Research on home patient lift transfer chair design of disabled elderly based on AD and TRIZ

Research on home patient lift transfer chair design of disabled elderly based on AD and TRIZ | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Research on home patient lift transfer chair design of disabled elderly based on AD and TRIZ Wei Liu, Wenhao Zhang, Hui Rong, Hailang Zhou, Xinyi Yang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6848008/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract With the rapid increase of China 's aging population, ensuring the safety of disabled elderly has become a prominent problem. Therefore, it is necessary to optimize the design of disabled elderly household patient lifts. Based on the multidisciplinary integration method, this research optimizes the design of a household patient lift for disabled elderly people. Firstly, the functional structure is analyzed by TRIZ functional modeling, and the function-structure mapping relationship is constructed based on axiomatic design theory(AD). Then TRIZ is used to analyze contradictory problems, find out the invention principle, and propose a reasonable patient lift transfer chair structure. The rationality and safety of the structure are verified by computer simulation, and the appearance design is determined based on the above results. The research results show that the method of integrating AD and TRIZ can effectively guide the design of patient lift products. The design of the chair is reasonable, easy to operate and stable in structure. It can effectively make up for the lack of research in related fields and promote the innovative development of the elderly auxiliary industry. Humanities/Health humanities Social science/Science technology and society patient lift disabled elderly axiomatic design TRIZ Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 1 Introduction As a developing country, China's population aging shows a trend of large scale and rapid growth [ 1 ]. With the irreversible evolution of China's aging population, the disability rate for activities of daily living(ADL) of the elderly population is significantly higher [ 2 ]. Due to chronic diseases, disabilities and other reasons, the ability of the elderly to take care of themselves is affected, so they need others to assist in completing daily activities [ 3 ]. lower extremity motor dysfunction is one of the most important manifestations of disability in the elderly [ 4 ]. It is difficult for the elderly with lower limb motor dysfunction to exercise stably with normal gait, and their daily life behaviors such as sitting up and walking are seriously affected [ 5 ]. Patient lifts are devices for lifting, transferring and repositioning to help the elderly with moderate or total disability to transfer horizontally and vertically. It is the first choice for nursing staff to reduce the risk of accidents and prevent the injury of disabled elderly when they carry out one-to-one or one-to-many nursing [ 6 ][ 7 ]. From the relevant data, the correct promotion of related technologies and the use of patient lift devices can effectively reduce the risk of injury in the disabled elderly [ 8 ]. However, at present, there are some problems in the household patient lifts on the market, such as scarcity of categories, single function, poor comfort, complicated operation steps and lack of aesthetic feeling. Therefore, in order to alleviate this situation, this research improves the design of a household patient lift on the Chinese market, improves the comfort and safety of the elderly during the transfer, reduces the operation complexity of the nursing staff, makes it more in line with the needs of users, and improves the user experience. Based on the design of rehabilitation aids [ 9 ], the principles of safety, ease of use, comfort, affinity and compensation (such as space accommodation, human physiology, mechanical structure and aesthetics) need to be considered in the design of the suitable-for-old patient lift [ 10 ]. Among them, comfort and safety during transportation are the most important [ 11 ]. The concept of patient lift product was first proposed by the United States and continuously optimized. In 1975, Brown of the United States created a precedent for the study of patient lifts [ 12 ], Hakamiun proposed a support leg structure that can be linearly retractable and angled to improve the passability of the patient lift device [ 13 ]. Martin et al.designed a stable and safe lifting device to make the lifting device easier to use and more comfortable [ 14 ]. The existing research on the design of patient lift device for elderly lower limb disorders mainly focuses on the following aspects : (1) Design improvement and optimization of mechanical structure based on ergonomics. For example, Alireza et al.improved the structure of the lift transfer chair with the motor as the lifting bracket as the main movement, and designed a special lifting auxiliary device ' Rakutateru ' that does not use the motor [ 15 ]. Based on ergonomics, Helen et al.proposed a mechanism to add suspenders to allow the device to be compatible with commercially available slings to reduce the load of the device and reduce the price of household person lift transfer aids [ 16 ]. (2) Application of computer simulation technology and advanced robot technology. Christensen et al.constructed a dynamic full-body exoskeleton ' FB-AXO ' that includes motion compatibility and modularization to assist the elderly in daily full-body movements, such as normal walking, standing, bending, and performing weight lifting and carrying tasks [ 17 ]. By testing the effectiveness of EMG sensors and IMU motion sensors as auxiliary equipment, Kong et al.reduced the workload of lifting auxiliary devices for nursing staff in performing patient lift tasks [ 18 ]. Wu et al.optimized and designed a transfer-assisted robot through biomechanical analysis software to help the elderly and the disabled stand and move. The robot uses traction-assisted methods to lift the patient to reduce the lower limb muscle force of the user during standing [ 19 ]. Tian et al.designed and analyzed a new type of personnel transfer auxiliary system named E-Pat based on the theory of relative static contact point and STM32 chip, and evaluated the performance of the equipment by analytic hierarchy process(AHP) [ 20 ]. (3) Focus on user experience and needs. Humphreys et al.tested the prototype lift and compared it with the lifts on the current market. By testing the user needs of 19 volunteers, they developed a new type of advanced machine-assisted lift [ 21 ]. Based on the needs of sitting to standing(STS) movement in the daily life of people with lower limb disorders, Purwar et al.designed a transfer-assist device to help STS movement [ 22 ]. Although these studies have performed well in technological innovation, they are less integrated in the disciplines of related research. This paper will use multidisciplinary research methods to carry out the improved design research of a patient lift, and carry out the structural design on the basis of user needs. Axiomatic design (AD) is a normative engineering design theory, which can provide a systematic basis for design decisions [ 23 ]. The concept of contradiction in TRIZ is similar to the coupling design in AD, the so-called coupling, that is, the adjustment of a design parameter, will affect multiple functional requirements variables at the same time [24][25], and the two have inherent consistency and compatibility. Through the relevant tools of TRIZ, the coupling design can be transformed into uncoupled or decoupled design [ 26 ]. By combining AD with TRIZ, the transformation of demand-function-structure contradiction is realized, and the contradiction analysis method is used to solve the problem objectively and accurately. The method of using AD and TRIZ to solve the problems encountered in product innovation has been applied in many fields. Combined with the concept of modular design, Yang et al.used AD to decompose the function and structure of the shield machine tool changer robot, and use TRIZ to solve the design contradiction [ 27 ].Xiao et al.designed a new type of giant SBM cutterhead, TRIZ tools were used to eliminate engineering conflicts in the design process and generate innovative ideas firstly, then based on the independence axiom in AD, functional requirements and design parameters were decomposed. [ 28 ]. Although these methods are feasible in various cases, the AD-TRIZ combination method has not been applied to the design of aging-friendly lift and transfer assist devices. There is a research gap in applying this method to the decision-making and evaluation system of patient lift transfer device design to meet the needs of different users [ 29 ]. In summary, the current research on the design of similar products mainly focuses on the optimization of mechanical structure or only focuses on the analysis of user needs, and lacks systematic design decision-making and evaluation methods of multidisciplinary integration. In order to optimize these problems, this study takes patient lift as the research center, and the research perspective is comprehensive and interdisciplinary. It aims to improve the use experience of household patient lift devices, help the innovative development of household patient lift transfer devices, and provide theoretical basis and case reference for the innovation research of related products. 2 Axiomatic design(AD) AD is devoted to enhancing the logic in the process of design scheme generation, and has significant theoretical advantages in conceptual decision-making. It can effectively decompose and hierarchically define the goal of the overall system in product design [30][ 31 ]. The Independent Axiom(IA) in the AD requires that the role and function of each product component in the product system in the design scheme are as independent as possible, that is, to try to ensure that the functions of the product components do not affect each other. When using the IA, it is necessary to construct the mapping relationship between function and structure and judge the coupling of the design matrix. According to Eq. 1 , it is judged whether the design matrix is coupled [ 32 ].In the figure, ' X ' indicates that the design parameters have an impact on the functional requirements, and ' O ' indicates that the design parameters have no effect on the functional requirements. Through AD, user needs can be transformed into specific product functions, and the contradiction between function and structure can be constructed and analyzed by using IA. $$\:\begin{array}{c}\left[A\right]=\left[\begin{array}{ccc}X&\:0&\:0\\\:0&\:X&\:0\\\:0&\:0&\:X\end{array}\right]\left[A\right]=\left[\begin{array}{ccc}X&\:0&\:0\\\:0&\:X&\:0\\\:X&\:X&\:X\end{array}\right]\left[A\right]=\left[\begin{array}{ccc}X&\:0&\:X\\\:0&\:X&\:X\\\:X&\:X&\:X\end{array}\right]\\\:\text{(}\text{a}\text{)}\text{U}\text{n}\text{c}\text{o}\text{u}\text{p}\text{l}\text{e}\text{d}\text{}\text{d}\text{e}\text{s}\text{i}\text{g}\text{n}\text{}\text{(}\text{b}\text{)}\text{Q}\text{u}\text{a}\text{s}\text{i}\text{-}\text{c}\text{o}\text{u}\text{p}\text{l}\text{i}\text{n}\text{g}\text{}\text{d}\text{e}\text{s}\text{i}\text{g}\text{n}\text{(}\text{c}\text{)}\text{C}\text{o}\text{u}\text{p}\text{l}\text{i}\text{n}\text{g}\text{}\text{d}\text{e}\text{s}\text{i}\text{g}\text{n}\end{array}$$ 1 3TRIZ TRIZ is an effective method to develop new systems (technologies). It can be used for product function modeling, analysis of functional relationships between product components, and help designers understand product structure and functional principles. It has incomparable advantages in solving problems and innovation [ 33 ]. In functional modeling, products and product components are defined by systems and components, and the environment, people and things that interact with products are defined as super-system components. Functional modeling decomposes the structure and function of the product through product component analysis and component function analysis. Finally, the functional model diagram is used to illustrate the relationship between product components, as shown in Fig. 1 [ 34 ]. The functional modeling of the product is helpful for the designer to understand the structure principle of the product and lay the foundation for the product optimization. Using contradiction to define problems and using contradiction matrix to solve problems is one of the most commonly used methods in TRIZ [ 35 ]. TRIZ defines two kinds of contradictions, namely technical contradiction and physical contradiction. When the technical contradiction occurs, the change of a certain attribute in the system will lead to the deterioration of other attributes. When the physical contradiction occurs, the same parameter in the system will not exist at the same time under different needs [ 36 ]. The design elements are transformed into the corresponding general engineering parameters, and the invention principles of solving problems can be found by comparing the contradiction matrix table. Table 1 is the general engineering parameters defined in TRIZ, and Table 2 is the inventive principles provided by TRIZ [ 37 ][ 38 ]. Table 1 General engineering parameters of TRIZ No. Engineering parameter No. Engineering parameter 1 Weight of moving object 21 Power 2 Weight of non-moving object 22 Waste of energy 3 Length of moving object 23 Waste of substance 4 Length of non-moving object 24 Loss of information 5 Area of moving object 25 Waste of time 6 Area of non-moving object 26 Amount of substance 7 Volume of moving object 27 Reliability 8 Volume of non-moving object 28 Accuracy of measurement 9 Speed 29 Accuracy of manufacture 10 Force 30 Harmful factors acting on object 11 Tension/pressure 31 Harmful side effects 12 Shape 32 Manufacturing 13 Stability of object 33 Convenience of use 14 Strength 34 Reparability 15 Durability of moving object 35 Adaptability 16 Durability of non-moving object 36 Complexity of device 17 Temperature 37 Complexity of control 18 Brightness 38 Level of automation 19 Energy spent by moving object 39 Productivity 20 Energy spent by non-moving object Table 2 Invention principles of TRIZ No. Principle No. Principle 1 Segmentation 21 Skipping 2 Taking out 22 Blessing in disguise 3 Local quality 23 Feedback 4 Asymmetry 24 Intermediary 5 Merging 25 Self-service 6 Universality 26 Copying 7 Nested doll 27 Cheap short-living object 8 Anti-weight 28 Mechanics substitution 9 Preliminary anti-action 29 Pneumatics and hydraulics 10 Preliminary action 30 Flexible shells and thin films 11 Beforehand cushioning 31 Porous materials 12 Equipotentiality 32 Color changes 13 The other way round 33 Homogeneity 14 Spheroidality-curvature 34 Discarding and recovering 15 Dynamics 35 Parameter change 16 Partial or excessive actions 36 Phase transition 17 Another dimension 37 Thermal expansion 18 Mechanical vibration 38 Strong oxidants 19 Periodic action 39 Inert atmosphere 20 Continuity of useful action 40 Composite materials The path of TRIZ to solve the problem is to abstract the specific problems to be solved into general problems [ 39 ]. The rational use of contradiction matrix can effectively solve the function-structure contradiction in product design. The general process is to use the above TRIZ tools to transform the elements in the product function-structure contradiction into general engineering parameters, analyze the improved parameters and corresponding deterioration parameters, draw the Archie Schuler conflict matrix, find the appropriate invention principle, optimize and adjust the existing product structure, and finally complete the product design based on the innovative structure. 4 Design process framework In this study, the research process is divided into three parts by means of multidisciplinary combination. Firstly, the TRIZ functional modeling is used to construct the function model of the patient lift and analyze the function structure. Secondly, the function-structure matrix of the device is constructed based on the IA in the AD and the contradiction between function and structure is analyzed. The contradiction analysis method in TRIZ is used to transform the elements in the function-structure contradiction into structural optimization design and verified by computer simulation. After the verification results are obtained, the appearance design of the patient lift is completed based on the best scheme of structural design. Figure 2 summarizes the research structure of this paper. 5 Functional structure analysis based on TRIZ Patient lift transfer chair is a kind of household patient lift device with high popularity. This paper focuses on the design and research of manual patient lift transfer chair which is suitable for use in home environment. Based on the typical products in the market, its structure is analyzed, and the functional modeling analysis framework in TRIZ is applied to construct the function model of the chair, as shown in Fig. 3 . According to the product function model, the component analysis of the chair is carried out. The chair is composed of backrest, joystick, armrest, seat plate, cushion, lifting mechanism (including outer pipe, bearing, screw, threaded pipe and other components), backrest lock, bracket lock, bracket, basin frame, basin, base, pedal, universal wheel, foot brake, directional wheel and other system components. In the process of use, it is necessary to interact with the elderly, nursing staff and the ground. Therefore, the elderly, nursing staff and the ground are super system components. The functional relationship between the components is analyzed, and the functional types (basic function, auxiliary function and harmful function) and functional levels (normal, insufficient and excessive) are judged, as shown in Table 3. Table.3 Component function analysis table Functional Carrier Function Object Function Type Function Level Backrest Module Support Elderly Basic Function Normal Lift Control Module Control Lifting Module Basic Function Normal Seat Module Support Elderly Basic Function Normal Lifting Module Lift Lift Control Module Auxiliary Function Normal Lift Push Handle Module Basic Function Normal Lift Seat Module Basic Function Normal Lift Sanitation Module Auxiliary Function Normal Safety Module Lock Backrest Module Basic Function Normal Lock Support Frame Module Basic Function Normal Support Frame Module Support Backrest Module Basic Function Normal Fix Seat Module Basic Function Normal Health module Service Elderly Basic Function Normal Base Module Support Lifting Module Basic Function Normal Fix Footrest Module Basic Function Normal Connect Mobility Module Basic Function Normal Footrest Module Support Elderly Basic Function Normal Mobility Module Move Base Module Basic Function Normal Caregiver Open/Close Backrest Module Basic Function Normal Push Backrest Module Auxiliary Function Normal Open/Close Seat Module Basic Function Normal Open/Close Support Frame Module Basic Function Normal Control Lift Control Module Basic Function Normal Lock Safety Module Basic Function Normal Clean Sanitation Module Basic Function Normal Push Push Handle Module Basic Function Normal Move Elderly Basic Function Normal Ground Support Mobility Module Basic Function Normal Ground Support Caregiver Basic Function Normal According to the component function analysis table, the function model diagram of the shift machine is drawn. In this study, the function model of the chair is mainly drawn with the elderly as the analysis target, as shown in Fig. 4 . 6 Contradiction analysis based on AD Based on the function model diagram drawn by TRIZ modeling analysis, the functional structure of the chair is listed. Using the IA in AD, the mapping relationship between the functional requirements and the structure is constructed. As shown in Table 4 , FR (Function Requirements) represents the functional requirements of the product, and DP (Design Parameters) represents the corresponding product structure [ 40 ]. Table 4 Mapping relationship between functional requirements and design parameters Functional Requirements (FR) Design Parameters (DP) Stable and sturdy body (FR 1 ) Frame structure (DP 1 ) Safe protective facilities (FR 2 ) Protective facilities (DP 2 ) Sensitive braking (FR 3 ) Brake structure (DP 3 ) Strong load-bearing capacity (FR 4 ) Frame material (DP 4 ) Reasonable size of the transfer device (FR 5 ) Frame structure (DP 5 ) Reasonable lifting range (FR 6 ) Lifting structure (DP 6 ) Reduce space occupied during transfer operations (FR 7 ) Optimized auxiliary transfer structure (DP 7 ) Rust-proof materials (FR 8 ) Frame material (DP 8 ) Aesthetically pleasing (FR 9 ) Appearance of the transfer device (DP 9 ) Height adjustment function (FR 10 ) Lifting structure (DP 10 ) Smooth movement and easy steering (FR 11 ) Wheels (DP 11 ) Auxiliary transfer function (FR 12 ) Open-close seat plate structure (DP 12 ) Auxiliary lifting function (FR 13 ) Auxiliary lifting structure (DP 13 ) Reduce the weight of the transfer device (FR 14 ) Frame material (DP 14 ) Improve seating comfort (FR 15 ) Seat material (DP 15 ) Adjustable toilet opening size (FR 16 ) Toilet opening structure (DP 16 ) Then, the interaction between functional requirements and design parameters is further analyzed, and the design matrix is listed, as shown in Eq. 2 . In the formula, ' X ' indicates that the design parameters have an effect on the functional requirements, and ' O ' indicates that the design parameters have no effect on the functional requirements. $$\:\left\{\begin{array}{c}F{R}_{1}\\\:F{R}_{2}\\\:F{R}_{3}\\\:F{R}_{4}\\\:F{R}_{5}\\\:F{R}_{6}\\\:F{R}_{7}\\\:F{R}_{8}\\\:F{R}_{9}\\\:F{R}_{10}\\\:F{R}_{11}\\\:F{R}_{12}\\\:F{R}_{13}\\\:F{R}_{14}\\\:F{R}_{15}\\\:F{R}_{16}\end{array}\right\}=\left[\begin{array}{cccccccccccccccc}X&\:O&\:O&\:X&\:X&\:O&\:X&\:X&\:O&\:O&\:O&\:X&\:O&\:X&\:O&\:O\\\:O&\:X&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O\\\:O&\:O&\:X&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O\\\:X&\:O&\:O&\:X&\:X&\:O&\:X&\:X&\:O&\:O&\:O&\:X&\:O&\:X&\:O&\:O\\\:X&\:O&\:O&\:O&\:X&\:X&\:X&\:O&\:O&\:X&\:O&\:X&\:O&\:O&\:O&\:O\\\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:O&\:O&\:O\\\:O&\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:O\\\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O\\\:X&\:X&\:O&\:X&\:X&\:O&\:X&\:X&\:X&\:O&\:O&\:X&\:O&\:X&\:X&\:O\\\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:O&\:O&\:O\\\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O\\\:O&\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:O&\:X&\:X&\:O&\:O&\:O\\\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:O\\\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:O&\:O&\:X&\:X&\:O\\\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:X&\:X\\\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:O&\:X&\:O&\:O&\:O&\:X\end{array}\right]\bullet\:\left\{\begin{array}{c}D{P}_{1}\\\:D{P}_{2}\\\:D{P}_{3}\\\:D{P}_{4}\\\:D{P}_{5}\\\:D{P}_{6}\\\:D{P}_{7}\\\:D{P}_{8}\\\:D{P}_{9}\\\:D{P}_{1O}\\\:D{P}_{11}\\\:D{P}_{12}\\\:D{P}_{13}\\\:D{P}_{14}\\\:D{P}_{15}\\\:D{P}_{16}\end{array}\right\}$$ 2 After analyzing the coupling of the design matrix, the following functional-structural contradictions are obtained: the contradiction between the body stability (FR 1 ) and the frame material (DP 4 ), the contradiction between body stability (FR 1 ) and retractable seat structure (DP 7 ), the contradiction between the strong bearing capacity (FR 4 ) and the retractable base plate structure (DP 7 ), reduce the contradiction between the shift operation space (FR 7 ) and the retractable seat structure (DP 7 ), improve the contradiction between seat comfort (FR 15 ) and retractable seat plate structure (DP 7 ), the contradiction between the size adjustment function of the hole (FR 16 ) and the retractable seat plate structure (DP 7 ). Through in-depth analysis of these contradictions, the structural optimization design of the chair can be carried out. 7 Structural optimization design based on TRIZ 7.1 Contradiction resolution Based on the function-structure contradiction obtained from the above analysis, the factors that need to be improved and the factors that may deteriorate in each group of contradictions are further analyzed : (1) The contradiction between body stability (FR 1 ) and frame material (DP 4 ). The stability of the body requires high strength of the frame material, but the high strength of the frame material will increase the weight of the body, which is contradictory to the functional requirements of reducing the weight of the chair. (2) The contradiction between body stability (FR 1 ) and retractable seat structure (DP 7 ). The retractable seat plate structure has the function of auxiliary transfer, but it will affect the stability and safety of the body. (3) The contradiction between strong load-bearing capacity (FR 4 ) and retractable base plate structure (DP 7 ). The retractable seat plate is fixed by safety lock and other devices, which will affect the bearing capacity of the chair to a certain extent. (4) Reduce the contradiction between the transfer operation space (FR 7 ) and the retractable seat structure (DP 7 ). Retractable seating plates can help transfer in existing products, but need to occupy a larger lateral space when fully deployed. (5) Improve the contradiction between seat comfort (FR 15 ) and retractable seat plate structure (DP 7 ). The structure of the retractable seat plate is affected by the processing, assembly and displacement operation. There is a situation where the seat plates on both sides are not aligned during the opening and closing, which has an impact on the seat comfort. (6) The contradiction between the hole size adjustment function (FR 16 ) and the retractable seat plate structure (DP 7 ). The position of the hole is set on both sides of the retractable seat plate, and the retractable seat plate will increase the complexity of the structure of the hole size adjustment. The factors that need to be improved and the factors that may deteriorate are extracted and transformed into general engineering parameters in TRIZ, as shown in Table 5 . Table 5 General factor conversion N Factors to Improve Factors That May Deteriorate O Factors General parameter Factors General parameter 1 Body stability factor Stability of object (NO.13) Body weight Weight of non-moving object (NO.2) 2 Achieving transfer function by adjusting seat plate position Shape (NO.12) Body stability Stability of object (NO.13) 3 Seat separates during transfer and merges when seated Adaptability(NO.35) Load-bearing capacity Strength (NO.14) 4 Assisting in repositioning the elderly Force (NO.10) Lateral distance when seat plate is fully extended Length of non-moving object (NO.4) 5 Ensuring alignment of seat plate during opening/closing for improved comfort Reliability (NO.27) Difficulty in manufacturing open-close seat plate structure Manufacturing (NO.32) 6 Toilet opening size adjustment mechanism Area of non-moving object(NO.6) Complexity of toilet opening structure Complexity of device (NO.36) The general parameters obtained from the conversion in Table 5 are combined with the Archie Schuler conflict matrix table to find the number of the invention principles corresponding to the intersection of the improved parameters and the deteriorated parameters, and Table 6 is sorted out. By comparing the obtained invention principles with the design objectives of the chair, the invention principles of No.1, No.2, No.8, No.10, No.15 and No.40 were finally selected as the guiding method for the design of the patient lift transfer chair, and the structural optimization design was carried out. Table 6 Invention principle Improved parameters Deterioration parameters Weight of non-moving object(NO.2) Length of non-moving object(NO.4) Stability of object(NO.13) Strength(NO.14) Manufacturing(NO.32) Complexity of device(NO.36) Area of non-moving object(NO.6) 30,2,14,18 26,7,9,39 2,38 40 40,16 1,18,36 Force(NO.10) 18,13,1,28 28,10 35,10,21 35,10,14,27 15,37,18,1 26,35,10,18 Shape(NO.12) 15,10,26,3 13,14,10,7 33,1,18,4 30,14,10,40 1,32,17,28 16,29,1,28 Stability of object(NO.13) 26,39,1,40 37 / 17,9,15 35,19 2,35,22,26 Reliability(NO.27) 3,10,8,28 15,29,28,11 / 11,28 / 13,35,1 The specific components of the chair include seat module, toilet hole adjustment module, seat lifting module, armpit lifting module and moving module. The following is the structural optimization design of each module. (1) Structure optimization of armpit lifting module Based on the principle of invention No.10, the principle of pre-action, pre-placed objects, so that it can play a role in the most convenient position. Then, based on the principle of invention No.8, the principle of weight compensation, a certain object is combined with another object that can provide lift to compensate its weight. According to the above two invention principles, a hydraulic rod is designed to provide lift for the armpit to lift the elderly so that their hips can leave the bed surface, and then the seat is moved under the elderly. After the seat is fixed, the elderly are placed on the seat to complete the transfer operation. This kind of operation process will reduce the physical burden of nursing staff and the elderly, and at the same time facilitate the behavior of the elderly, such as wearing and taking off their pants when they go to the toilet. The optimized armpit lifting module is fixedly connected to the seat lifting module. The lifting principle is as follows : the nursing staff adjusts the length of the hydraulic rod by pressing the control handle. When the hydraulic rod becomes longer, the bracket will rotate counterclockwise around the rotation axis, and the height of the armpit will decrease. When the hydraulic rod becomes shorter, the support will have a tendency to rotate clockwise around the rotation axis, and the height of the armpit will rise. (2) Seat module structure optimization Based on the principle of invention No.1, the principle of segmentation, an object is divided into independent parts. Then, based on the principle of invention No.2, the extraction principle, parts or attributes that have a negative impact are extracted from the object. According to the above two invention principles, the seat is separated from the main body of the chair and becomes a separate component. First, the ' separated ' attributes of the seat plate are extracted to make the seat a whole, which does not need to occupy a large lateral space when used, and also improves comfort. The ' bilateral ' attribute is extracted and the single-axis lifting is used to avoid the inconsistency of the height on both sides. The seat module no longer uses the retractable seat plate and the backrest, and is separated from the main body of the lift frame to become an independent component. When used, it is installed on the seat lifting module by means of plug-in. (3) Structure optimization of the toilet hole adjustment module Based on the principle of invention No.15, the dynamic principle, the performance of the object or environment is adjusted to achieve the optimal state in each stage of the work. According to this invention principle, the structure of the hole is optimized to improve the comfort of the seat, and the size adjustment mechanism is designed to make the hole open when needed and close when not needed, which can make the lift better suitable for sitting and resting. The elderly can sit on the chair for a long time. With the help of the iris structure, the adjustment of the size of the hole is realized. The toilet hole adjustment module is installed inside the seat module. The adjustment principle is as follows: the nursing staff rotates the control handle, and the driving rod drives the movable pin to move in the driving limit ring, thereby driving the panel to move, so as to realize the function of adjusting the size of the hole. (4) Material optimization Based on the principle of invention No.40, the principle of composite materials, composite materials are used instead of homogeneous materials to improve the problem that metal materials are the main components of the frame, seat plate and backrest of the current transfer machine, which leads to the overweight of the product. During the design process, the non-load-bearing parts can be replaced with other materials to reduce the weight of the chair. After the comprehensive application of the above invention principles, the structure of the patient lift transfer chair is shown in Fig. 5. In terms of product function, the design scheme has three main advantages compared with various types of patient lift transfer chairs on the market. First of all, this chair can lift the elderly more easily, reduce the manual labor of the nursing staff when assisting the elderly to move, and also reduce the difficulty of the elderly to get up. Secondly, this chair can help the elderly wear pants more easily by hydraulic lifting when assisting the elderly to go to the toilet. Finally, this chair can not only ensure the comfort of the elderly when they are sitting and resting, but also provide convenience for the elderly to go to the toilet by adjusting the size of the toilet hole on the seat surface. 7.2 Structure simulation In order to verify the safety of the chair structure, the main structure of the chair is simulated and verified. Because the density of high carbon steel and stainless steel is greater than that of aluminum alloy, the weight of the main structural material of the chair is large. Therefore, the selection range is reduced to aluminum alloy. Finally, 6061-T6 aluminum alloy with excellent comprehensive performance and wide application is determined. Its yield strength is usually between 240MPa and 300MPa, Poisson 's ratio is about 0.3, and elastic modulus is about 60GPa. In the method of safety inspection, Hu et al.have used SolidWorks simulation and ABAQUS finite element model simulation [ 41 ][ 42 ]. In this study, the model file is saved in igs format and imported into Ansys Workbench 19.0 for static analysis. After the meshing is completed, a force of 1000N is applied to the chair surface, and the constraint of the contact between the chair leg and the ground is set. Finally, the simulation solution is carried out. The yield strength of the aluminum alloy is set to 280MPa, the Poisson 's ratio is set to 0.3, and the elastic modulus is set to 60GPa to analyze the stress of the main structure of the chair. The simulation results are shown in Fig. 6 . The equivalent stress diagram shows that there is no stress area exceeding 280MPa in the main structure of the fuselage, and the maximum stress is 173.03MPa. Therefore, the main structure of the chair is reasonable and can bear at least 100kg, which meets the needs of most users. 8 Overall design of patient lift transfer chair The chair needs to be used in conjunction with furniture such as beds, sofas, toilets, etc. It also requires frequent access to relatively narrow spaces such as toilets. Therefore, according to the basic human body size data, as well as space size data such as furniture and toilets, the product size of the chair is determined, as shown in Table 7 . The main reference design standards are ' Chinese adult body size ' ( GB / T 1000–2023 ) and ' main size of furniture bed ' ( GB / T 3328 − 2016 ). Table 7 Survey of dimensions affecting the use of lifts Size category Size category(mm) Dimension requirement(mm) Bed height 400 H Maximum seat surface ≥650 Mattress 200–250 Sofa / Couch 350–420 H Minimum seat surface ≥350 Toilet 350–400 Under-bed clearance 120–180 H Bottom ≤120 Bathroom door width 600–700 W Fuselage ≤600 Male chest width 330 W Chest bracket =330 Female chest width 319 Male shoulder width 408 W Axillary support =385 Female shoulder width 378 According to the survey size, the height of most beds is 400mm, and the height of mattresses is between 200mm and 250mm. Therefore, the maximum height of the chair seat surface H Maximum seat surface ≥650mm, the height of the sofa is between 350-420mm, and the height of the toilet is between 350-400mm. Therefore, the minimum height of the seat surface of the chair is determined to be H Minimum seat surface ≥350mm. The gap distance under the bed is generally 120-180mm, so the bottom height of the chair is H Bottom ≤120mm. The width of the toilet door is generally 600-700mm, so the body width of the chair is W Fuselage ≤ 600mm. According to the national standard of Chinese adult body size GB / T 10000 − 2023, the 95th percentile sizes of chest width and shoulder width of adult males aged 61–70 are 330mm and 408mm, respectively, while the sizes of adult females aged 61–70 are 319mm and 378mm, respectively. Based on the above data research, the height adjustment range of the chair’s seat surface is set to 350–700 mm, the bottom height is 95 mm, the widest part of the lift transfer chair is 57mm, the chest width is 330mm, and the armpit spacing is 385mm. The final appearance effect and three-dimensional size of the product are shown in Fig. 7 . The modeling design and color selection of the lift transfer chair are mainly based on the home environment and the product attributes of medical assistance. The home use scenario of the lift is shown in Fig. 8 . The modeling of this chair avoids too complicated design, but mainly focuses on simple and smooth lines. Through the cutting of the cube and the division of the block surface, the modern sense of the design is increased, which reflects the professionalism of the equipment and can also adapt to most of the home environment. In the choice of color, the design scheme with blue, gray as the main color. Blue gives people a sense of quiet, trust and professionalism, and is suitable for medical and rehabilitation equipment. Gray represents stability, elegance and sense of technology, and enhances the professional image of the product. In order to ensure the high strength and light weight of the seat, PP material with low density, light weight, good mechanical properties, low production cost, fast and accurate production is selected as the material of the seat. The armpit and chest support are filled with sponge. This material has good elasticity and air permeability, which can provide comfortable support while reducing friction and discomfort. The hydraulic control handle is made of rubber material, and the surface is designed with anti-skid texture. The transfer operation steps of this chair are shown in Fig. 9 . First of all, the nursing staff moves the chair to the bed, and steps on the brake. The second step, the nursing staff adjusts the rotating handle, the chair to the appropriate height. The third step, the nursing staff controls armpit lift through the handle. In the fourth step, the nursing staff puts the armpit under the armpit of the elderly and then lifts the armpit. The fifth step, the nursing staff gets to install the seat on the chair. The sixth step, the nursing staff controls the armpit to drop the elderly on the seat. The operation steps of using this chair to go to the toilet are shown in Fig. 10 . First, the nurse pushes the chair over the toilet. In the second step, the nursing staff adjusts the height of the chair so that the seat can stay on the toilet. The third step, the nursing staff adjusts the size of the toilet hole through the handle on the side of the seat. The fourth step, in the process of toileting, the nursing staff uses the armrest to lift the elderly and assists the elderly to wear pants. 9 Results And Discussion Taking the innovative design of household patient lift device for the disabled elderly as an example, the feasibility of the design is verified. The design of age-appropriate patient lift devices based on AD-TRIZ combination method needs to consider a variety of factors, and the process is complex [ 43 ]. The research results show that the qualitative and quantitative research on the potential needs of the disabled elderly is carried out by using the AD, TRIZ invention principle and other theoretical methods. The qualitative and quantitative factors are integrated in the design of the lift transfer chair, and the decision-making process becomes more scientific and balanced. The improvement of its overall performance is mainly divided into four aspects: human-machine relationship, operation steps, effort saving and space requirements. In addition, the decision to integrate multiple disciplines greatly improves the feasibility of the solution and supports the results of previous studies. For example, through the combination of QFD and AHP, Chen et al.explored the research and development strategy of furniture laminated wood-based panels, providing a reference for the future application of similar environmentally friendly materials [44]. By integrating the Unified Theory of Acceptance and Use of Technology(UTAUT) and the Task-Technology Fit(TTF) model, Wang et al.developed and empirically tested a model to gain a deeper understanding of consumer acceptance of healthy wearable devices(HWDs)[ 45 ]. Yu et al.adopted the AHP-CRITIC-TOPSIS method to try to arouse the attraction of Chinese Funan wicker home furnishing products to young consumers in the Chinese market [ 46 ]. Xie et al.proposed an evaluation method based on AHP fusion gray correlation analysis(GCA ) to propose a green design reference scheme for kindergarten furniture [ 47 ]. Compared with previous studies, this study proposes a more novel product design method for patient lift device suitable for the elderly. The functional structure of the patient lift transfer chair is analyzed by using the functional modeling in TRIZ. The mapping relationship between the function and structure of the chair is constructed by establishing the design matrix based on the AD. The contradiction between function and structure is clarified based on the IA. Secondly, the factors that need to be optimized and the factors that may deteriorate in the contradiction are analyzed, and they are transformed into general parameters in TRIZ. With reference to the conflict matrix table of Archie Schuler, the appropriate invention principle is found, and a reasonable structure of the chair is proposed. Ansys Workbench 19.0 software is used to verify the load-bearing capacity of the lift transfer chair, and the final scheme of the optimal design of the chair is improved based on the verified feasible results. This research not only makes a breakthrough in the construction of product structure, but also proves the effectiveness of AD and TRIZ combination method as the guiding framework. In addition, this study also emphasizes multi-dimensional user experience to ensure that the design scheme is more in line with the actual needs, thereby improving the practicability and user satisfaction of the lift transfer chair. However, although significant progress has been made in the integration of related research content disciplines, there are still some limitations in this study. In the analysis of user needs, there is a lack of research on the subjective feelings of the elderly when using displacement aids; the preliminary test was carried out by computer simulation without verifying the strength and safety of the product structure. In addition, it is not possible to further optimize the design scheme through the feedback of market use. Therefore, in the future research, actual users can be invited to conduct qualitative research data to summarize and analyze the user's use characteristics, psychological characteristics and emotional needs, so as to improve the systematic and empirical nature of the research. In addition, in the future, the physical prototype will be made after the design scheme is put forward, so that the optimization of the design scheme will be more comprehensive after the user's actual use experience. 10 Conclusion In this study, AD and TRIZ innovation theory are successively applied to give full play to the complementary advantages of the two theoretical methods, and an interdisciplinary technical route suitable for the design and research of patient lift devices is formed, which effectively makes up for the weak integration of existing related research contents. It provides a clearer, specific and systematic theoretical guidance for the conceptual design process of the whole aging-oriented lift transfer devices, provides case reference for other people 's research, helps future designers to carry out more scientific and systematic design, improves the innovation, feasibility and user satisfaction of the design, promotes the innovation and development of the elderly assistive devices industry, and has made contributions to the cause of social pension. In addition, the research conclusions not only enrich the theoretical and practical research on the design of suitable aging lift transfer chair devices, but also provide a reference method and approach for the conceptual design of other product types. In summary, this study has important theoretical value, practical application value and social significance, but there are also some shortcomings. First of all, there is a lack of research on the subjective feelings of the elderly when using displacement aids, and there is a lack of emotional design in the proposed scheme. Secondly, after the functional structure is proposed, due to the large volume of the product and the lack of corresponding experimental environment, it is impossible to verify the strength and safety of the product structure, and can only be preliminarily tested by computer simulation. After the design scheme is put forward, the prototype and the actual product cannot be made due to the limitation of the actual conditions. The actual use effect of the design scheme has not been verified by experiments, and it cannot be further optimized through the use feedback scheme of the market. Future research can further discuss these technical principles in more detail. Declarations Funding The design, implementation, data analysis and conclusion writing of this study were not influenced by any financial sponsors. Author Contribution WL conceived the study and was responsible for the overall design and methodology, HR developed the framework ideas and content, WZ wrote the content and charted, and made a significant contribution to the interpretation of the results. HZ and XY participated in the literature review and manuscript preparation. All authors have read and agreed to the published version of the manuscript. Data availability Data sharing is not applicable to this research as no data were generated or analysed. References Zhang X, Han H (2023) Spatiotemporal Dynamic Characteristics and Causes of China’s Population Aging from 2000 to 2020. Sustainability 15:7212. https://doi.org/10.3390/su15097212 Wu H, Wang Y, Zhang H et al (2024) An investigation into the health status of the elderly population in China and the obstacles to achieving healthy aging. Sci Rep 14:31123. https://doi.org/10.1038/s41598-024-82443-2 Tian P, Wang G, Liu, Yaping Z, Juan (2021) Understanding Disabilities among the Elderly in China: Important Factors, Current Situation, and Future Perspective, Discrete Dynamics in Nature and Society, 6665351, 10 pages, 2021. https://doi.org/10.1155/2021/6665351 Wang T, Zhang B, Liu C, Liu T, Han Y, Wang S, Ferreira JP, Dong W, Zhang X (2022) A Review on the Rehabilitation Exoskeletons for the Lower Limbs of the Elderly and the Disabled. Electronics 11:388. https://doi.org/10.3390/electronics11030388 Li W, Liu K, Li C et al (2022) Development and Evaluation of a Wearable Lower Limb Rehabilitation Robot. J Bionic Eng 19:688–699. https://doi.org/10.1007/s42235-022-00172-6 Schoenfisch AL, Kucera KL, Lipscomb HJ, McIlvaine J, Becherer L, James T, Avent (2019) Susan. Use of Assistive Devices to Lift, Transfer, and Reposition Hospital Patients. Nursing Research 68(1):p 3–12, 1/2 | 10.1097/NNR.0000000000000325 Nelson A, Matz M, Chen F, Siddharthan K, Lloyd J, Fragala G (2006) Development and evaluation of a multifaceted ergonomics program to prevent injuries associated with patient handling tasks. Int J Nurs Stud 43:717–733 Sivakanthan S, Blaauw E, Greenhalgh M, Koontz AM, Vegter R, Cooper, Rory A (2019) Person transfer assist systems: a literature review. Disabil Rehabilitation: Assist Technol 1–10. 10.1080/17483107.2019.1673833 Venkat K, Vijay K, K. G A et al (1997) Design and Virtual Prototyping of Rehabilitation Aids[C]//University of Pennsylvania Strasser H Compatibility as guiding principle for ergonomics work design and preventive occupational health and safety[J]. Z für Arbeitswissenschaft 2021, 76(3):1–35 Tian Y et al (2021) Design and Evaluation of a Novel Person Transfer Assist System, in IEEE Access, vol. 9, pp. 14306–14318. 10.1109/ACCESS.2021.3051677 Brown CC Patient Lift and Exercise Apparatus: U.S. Patent 3,877,421[P].1975-04-15 Hakamiun R, Genereux DP, Falin MD et al Patient lift: U S Patent 6,289,534[P].2001-09-18. Martin WE, Barr R Patient Lift Device: U.S. Patent 8,793,822[P].2014-08-05 Ahrary A, Yang W-S, Inada M Kazumi Nakamatsu,Development of the Lift Assist Chair for the Elderly People Rakutateru,Procedia Computer Science,131,2018,Pages 31–37,ISSN 1877 – 0509, https://doi.org/10.1016/j.procs.2018.04.182 Heacock H, Paris-Seeley N, Tokuno C, Frederking S, Keane B, Mattie J, Kanigan R James Watzke,Development and evaluation of an affordable lift device to reduce musculo-skeletal injuries among home support workers,Applied Ergonomics,35, Issue 4,2004,Pages 393–399,ISSN 0003-6870, https://doi.org/10.1016/j.apergo.2004.02.006 Simon Christensen S, Rafique (2021) Shaoping Bai,Design of a powered full-body exoskeleton for physical assistance of elderly people,International Journal of Advanced Robotic Systems,Vol Issue 11, pp. -Issue published date: December-01-2021 Kong YK, Choi KH, Park SS, Shim JW, Shim HH (2023) Evaluation of the Efficacy of a Lift-Assist Device Regarding Caregiver Posture and Muscle Load for Transferring Tasks. Int J Environ Res Public Health 20(2):1174. 10.3390/ijerph20021174 PMID: 36673934; PMCID: PMC9858700 Wu R, Wang J, Chen W, Wang P (2020) Design of a transfer robot for the assistance of elderly and disabled. Adv Robot 35(3–4):194–204. https://doi.org/10.1080/01691864.2020.1819875 Tian Y et al (2021) Design and Evaluation of a Novel Person Transfer Assist System, in IEEE Access, vol. 9, pp. 14306–14318. 10.1109/ACCESS.2021.3051677 Humphreys HC, Choi YM, Book WJ (2017) Advanced patient transfer assist device with intuitive interaction control. Assist Technol 35(1):3–13. https://doi.org/10.1080/10400435.2017.1396564 Anurag Purwar K, Bhargava Edward Behan,A multi-functional mobility assist device for sit-to-stand motion,International Journal of Industrial Ergonomics,Volume 93,2023,103396,ISSN 0169–8141, https://doi.org/10.1016/j.ergon.2022.103396 Suh NP (1995) Designing-in of quality through axiomatic design. IEEE Transactions on Reliability, 44(2): pp. 256–264. Mann D.Axiomatic design and TRIZ: compatibilities and contradictions [J].TRIZ Journal 1999 4(6):34ཞ39 Mann D.Axiomatic design and TRIZ: compatibilities and contradictions(2) [J].TRIZ Journal 1999 4༈7༉:53ཞ58 Bai Z, Zhang S, ,Ding M et al Research on product innovation design of modularization based on theory of TRIZ and axiomatic design[J]. Adv Mech Eng 2018, 10(12):168781401881408–168781401881408 Mei Y, Yimin X, ,Lianhui J et al A modular design method based on TRIZ and AD and its application to cutter changing robot[J].Advances in Mechanical Engineering,2021,13(7) Jing X, Feixiang L, ,Mei Y et al An innovative design of mega shaft boring machine (SBM) cutterhead based on TRIZ and AD theory[J].Advances in Mechanical Engineering,2023,15(2) Wang T, Zhao Y, ,Zhang X et al Design of walking aids for the elderly based on the Kano-AHP-FEC method[J].Scientific Reports,2025,15(1):2663–2663 Qihua T, Yixian D, ,Xiangman Z et al Research on Integrated Model of Products' Conceptual Design Based on AD and TRIZ and its Application[C]//国际计算机辅助工业设计与概念设计学术会议主委会.Proceedings of 2011 IEEE 12th International Conference on Computer-Aided Industrial Design & Conceptual Design Vol.2.[出版者不详],2011:370–373 Osman Kulak S, Cebi Cengiz Kahraman,Applications of axiomatic design principles: A literature review,Expert Systems with Applications,Volume 37, Issue 9,2010,Pages 6705–6717,ISSN 0957–4174, https://doi.org/10.1016/j.eswa.2010.03.061 Gonçalves-Coelho AM, Neştian G, Cavique M et al (2012) Tackling with redundant design solutions through axiomatic design. Int J Precis Eng Manuf 13:1837–1843. https://doi.org/10.1007/s12541-012-0241-x Imoh M, Ilevbare D, Probert R, Phaal A review of TRIZ, and its benefits and challenges in practice,Technovation, 33, Issues 2–3,2013,Pages 30–37,ISSN 0166–4972, https://doi.org/10.1016/j.technovation.2012.11.003 Boxing T, Guohua G, ,Yongzhi L et al (2019) The Innovative Design of Seedling Transplanting Combination Mechanism with TRIZ[J].Journal of Physics: Conference Series,1267012073-012073 Sébastien Dubois, Guio RD, Rasovska I (2013) Resolution of Inventive Problems: Different Kind of Mechanisms[J]. Int J Syst Innov 1(4):2–10 Sheu D, Daniel (2020) Chiu Ming-Chuan, Cayard Dimitri.The 7 pillars of TRIZ philosophies[J]. Comput Ind Eng 146:106572 Lu S, Guo Y, Huang, Wei (2022) Shen, Min, Product Form Evolutionary Design Integrated with TRIZ Contradiction Matrix, Mathematical Problems in Engineering, 3844324, 12 pages, 2022. https://doi.org/10.1155/2022/3844324 Xie Q, Liu Q (2023) Application of TRIZ Innovation Method to In-Pipe Robot Design. Machines 11:912. https://doi.org/10.3390/machines11090912 Yan W, Liu H, Zanni-Merk C, Cavallucci D (2015) IngeniousTRIZ: An automatic ontology-based system for solving inventive problems. Knowl Based Syst 75:52–65. 10.1016/j.knosys.2014.11.015 Foley JT Sigrún Harðardóttir,Creative Axiomatic Design,Procedia CIRP, Volume 50,2016,Pages 240–245,ISSN 2212–8271, https://doi.org/10.1016/j.procir.2016.04.116 Li S, Hu W (2023) Study on mechanical strength of cantilever handrail joints for chair, BioResources. 18(1):209–219. 10.15376/biores.18.1.209-219 Yu R, Liu Y, Konukcu CA, Wengang H (2024) A method of simulating seat load for numerical analysis of wood chair structure. Wood Res 69(3):432–444. https://doi.org/10.37763/wr.1336-4561/69.3.432444 Wang T, Zhao Y, Zhang X et al (2025) Design of walking aids for the elderly based on the Kano-AHP-FEC method. Sci Rep 15:2663. https://doi.org/10.1038/s41598-025-85540-y Yushu Chen; Wenwen Sun. R&D Strategy Study of Customized Furniture with Film-Laminated Wood-Based Panels Based on an Analytic Hierarchy Process/Quality Function Deployment Integration Approach[J]. BioResources, (2023) 18(4): 8249–8263. 10.15376/biores.18.4.8249-8263 Wang H, Tao D, Yu N et al (2020) Understanding consumer acceptance of healthcare wearable devices: An integrated model of UTAUT and TTF[J]. Int J Med Informatics 139:104156 Yu S, Zhu Y, Liu F, Zhong Z, Sun J (2024) AHP-CRITIC-TOPSIS-based analysis of the influence of young people’s preferences on the design of Funan wicker home products, BioResources 19(4), 8216–8237 Xie X, Zhu J, Ding S, Chen J (2024) AHP and GCA Combined Approach to Green Design Evaluation of Kindergarten Furniture. Sustainability 16:1. https://doi.org/10.3390/su16010001 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6848008","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":496170435,"identity":"f65bfe93-49c1-400f-a547-7eedca9868f5","order_by":0,"name":"Wei Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyElEQVRIiWNgGAWjYBACPmYQaWDDwNh8AMhgI0ILG0RLGgNjWwKxWiDUYSCLaC3sPGYSHwrO5zG38RgwfCg7zMA/u4GQw3jMJGcY3C5mBGphnHHuMIPEnQOEtdzmMbid2Di/x4CZt+0wg4FEAhFa/hicS2wE2sL8l2gtDAYHIFoYidPCVv6zxyAZqIWt4GDPuXQeiRsEtPDzH95s8OOPXeLGNuaND36UWcvxzyCgBQ4MGxgYDgBpHiLVA4E88UpHwSgYBaNgpAEA6QA6hU5/4TwAAAAASUVORK5CYII=","orcid":"","institution":"Nanjing Forestry University","correspondingAuthor":true,"prefix":"","firstName":"Wei","middleName":"","lastName":"Liu","suffix":""},{"id":496170436,"identity":"c80e8141-cc36-4b48-b51e-84528299ead2","order_by":1,"name":"Wenhao Zhang","email":"","orcid":"","institution":"Nanjing Forestry University","correspondingAuthor":false,"prefix":"","firstName":"Wenhao","middleName":"","lastName":"Zhang","suffix":""},{"id":496170437,"identity":"b854223c-41ec-4601-8ff1-6e967842e29e","order_by":2,"name":"Hui Rong","email":"","orcid":"","institution":"Nanjing Forestry University","correspondingAuthor":false,"prefix":"","firstName":"Hui","middleName":"","lastName":"Rong","suffix":""},{"id":496170438,"identity":"ecd87e54-9361-43a8-9672-c4e3ebf053cd","order_by":3,"name":"Hailang Zhou","email":"","orcid":"","institution":"Nanjing Forestry University","correspondingAuthor":false,"prefix":"","firstName":"Hailang","middleName":"","lastName":"Zhou","suffix":""},{"id":496170439,"identity":"3b554335-5c99-457a-a94a-be8c8089fc70","order_by":4,"name":"Xinyi Yang","email":"","orcid":"","institution":"Nanjing Forestry University","correspondingAuthor":false,"prefix":"","firstName":"Xinyi","middleName":"","lastName":"Yang","suffix":""}],"badges":[],"createdAt":"2025-06-08 14:23:22","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6848008/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6848008/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88756222,"identity":"3c61f051-242c-4007-a92f-f8cd472798de","added_by":"auto","created_at":"2025-08-11 07:15:46","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":81558,"visible":true,"origin":"","legend":"\u003cp\u003eProduct functional model diagram\u003c/p\u003e","description":"","filename":"image1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/a209815d583663ee2357e3b8.jpeg"},{"id":88757180,"identity":"ef1354b5-2ffb-4d4d-8719-8acdf2eb3c25","added_by":"auto","created_at":"2025-08-11 07:23:46","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":220954,"visible":true,"origin":"","legend":"\u003cp\u003eDesign process frame\u003c/p\u003e","description":"","filename":"image2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/b17d78c2cffd04806501f10a.jpeg"},{"id":88756223,"identity":"2dbde6da-9989-4ea2-a512-2b52897d2e48","added_by":"auto","created_at":"2025-08-11 07:15:46","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":89791,"visible":true,"origin":"","legend":"\u003cp\u003eFunction model of the typical chair\u003c/p\u003e","description":"","filename":"image3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/4aeac19594d9c038ddb7da99.jpg"},{"id":88756225,"identity":"21a21caa-ad52-4482-a595-cf3caf151300","added_by":"auto","created_at":"2025-08-11 07:15:46","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":122319,"visible":true,"origin":"","legend":"\u003cp\u003eThe function model of the chair aiming at the elderly\u003c/p\u003e","description":"","filename":"image4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/d3180448c96fd61ffbfe5481.jpeg"},{"id":88756229,"identity":"4b348001-571f-4912-b22a-54c61c88184f","added_by":"auto","created_at":"2025-08-11 07:15:46","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":99935,"visible":true,"origin":"","legend":"\u003cp\u003eThe optimized structure of the chair\u003c/p\u003e","description":"","filename":"image5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/210c2f11d6e468c98bc0bb76.jpg"},{"id":88757184,"identity":"3cadedaa-d192-4072-8e17-4f4dca508259","added_by":"auto","created_at":"2025-08-11 07:23:46","extension":"jpeg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":117498,"visible":true,"origin":"","legend":"\u003cp\u003eEquivalent stress cloud diagram of main structure of chair\u003c/p\u003e","description":"","filename":"image6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/a536634a645e1b03ead16f55.jpeg"},{"id":88756232,"identity":"7ecff948-d948-4e6a-8a27-9fc717a83e0e","added_by":"auto","created_at":"2025-08-11 07:15:46","extension":"jpeg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":159172,"visible":true,"origin":"","legend":"\u003cp\u003eThree views of lift transfer chair\u003c/p\u003e","description":"","filename":"image7.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/9561469bb8c4018771cd0b13.jpeg"},{"id":88757187,"identity":"1b97a111-6f28-402a-9974-fc45450d9e3c","added_by":"auto","created_at":"2025-08-11 07:23:46","extension":"jpeg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":177674,"visible":true,"origin":"","legend":"\u003cp\u003eScene diagram of the use of the lift transfer chair\u003c/p\u003e","description":"","filename":"image8.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/fe2301432b192dc4fd832b95.jpeg"},{"id":88759185,"identity":"2203a268-f8ee-404a-b320-53383a3b7787","added_by":"auto","created_at":"2025-08-11 07:39:47","extension":"jpeg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":119078,"visible":true,"origin":"","legend":"\u003cp\u003eTransfer operation steps\u003c/p\u003e","description":"","filename":"image9.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/0780acac9eb84955c19c0294.jpeg"},{"id":88757192,"identity":"6cafbc52-a74a-4df8-9177-983c22df6a07","added_by":"auto","created_at":"2025-08-11 07:23:47","extension":"jpeg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":104059,"visible":true,"origin":"","legend":"\u003cp\u003eOperation steps of toileting\u003c/p\u003e","description":"","filename":"image10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/ffea122b379d074017e0fb44.jpeg"},{"id":91626662,"identity":"4f925af2-a550-4f64-8249-8f61aa3b4cb9","added_by":"auto","created_at":"2025-09-18 12:17:14","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2358080,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6848008/v1/36185d05-ad26-43db-afc4-51c27d732499.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Research on home patient lift transfer chair design of disabled elderly based on AD and TRIZ","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eAs a developing country, China's population aging shows a trend of large scale and rapid growth [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. With the irreversible evolution of China's aging population, the disability rate for activities of daily living(ADL) of the elderly population is significantly higher [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Due to chronic diseases, disabilities and other reasons, the ability of the elderly to take care of themselves is affected, so they need others to assist in completing daily activities [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. lower extremity motor dysfunction is one of the most important manifestations of disability in the elderly [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. It is difficult for the elderly with lower limb motor dysfunction to exercise stably with normal gait, and their daily life behaviors such as sitting up and walking are seriously affected [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Patient lifts are devices for lifting, transferring and repositioning to help the elderly with moderate or total disability to transfer horizontally and vertically. It is the first choice for nursing staff to reduce the risk of accidents and prevent the injury of disabled elderly when they carry out one-to-one or one-to-many nursing [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e][\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. From the relevant data, the correct promotion of related technologies and the use of patient lift devices can effectively reduce the risk of injury in the disabled elderly [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. However, at present, there are some problems in the household patient lifts on the market, such as scarcity of categories, single function, poor comfort, complicated operation steps and lack of aesthetic feeling. Therefore, in order to alleviate this situation, this research improves the design of a household patient lift on the Chinese market, improves the comfort and safety of the elderly during the transfer, reduces the operation complexity of the nursing staff, makes it more in line with the needs of users, and improves the user experience.\u003c/p\u003e\u003cp\u003eBased on the design of rehabilitation aids [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], the principles of safety, ease of use, comfort, affinity and compensation (such as space accommodation, human physiology, mechanical structure and aesthetics) need to be considered in the design of the suitable-for-old patient lift [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Among them, comfort and safety during transportation are the most important [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The concept of patient lift product was first proposed by the United States and continuously optimized. In 1975, Brown of the United States created a precedent for the study of patient lifts [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], Hakamiun proposed a support leg structure that can be linearly retractable and angled to improve the passability of the patient lift device [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Martin et al.designed a stable and safe lifting device to make the lifting device easier to use and more comfortable [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe existing research on the design of patient lift device for elderly lower limb disorders mainly focuses on the following aspects : (1) Design improvement and optimization of mechanical structure based on ergonomics. For example, Alireza et al.improved the structure of the lift transfer chair with the motor as the lifting bracket as the main movement, and designed a special lifting auxiliary device ' Rakutateru ' that does not use the motor [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Based on ergonomics, Helen et al.proposed a mechanism to add suspenders to allow the device to be compatible with commercially available slings to reduce the load of the device and reduce the price of household person lift transfer aids [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. (2) Application of computer simulation technology and advanced robot technology. Christensen et al.constructed a dynamic full-body exoskeleton ' FB-AXO ' that includes motion compatibility and modularization to assist the elderly in daily full-body movements, such as normal walking, standing, bending, and performing weight lifting and carrying tasks [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. By testing the effectiveness of EMG sensors and IMU motion sensors as auxiliary equipment, Kong et al.reduced the workload of lifting auxiliary devices for nursing staff in performing patient lift tasks [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Wu et al.optimized and designed a transfer-assisted robot through biomechanical analysis software to help the elderly and the disabled stand and move. The robot uses traction-assisted methods to lift the patient to reduce the lower limb muscle force of the user during standing [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Tian et al.designed and analyzed a new type of personnel transfer auxiliary system named E-Pat based on the theory of relative static contact point and STM32 chip, and evaluated the performance of the equipment by analytic hierarchy process(AHP) [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. (3) Focus on user experience and needs. Humphreys et al.tested the prototype lift and compared it with the lifts on the current market. By testing the user needs of 19 volunteers, they developed a new type of advanced machine-assisted lift [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Based on the needs of sitting to standing(STS) movement in the daily life of people with lower limb disorders, Purwar et al.designed a transfer-assist device to help STS movement [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAlthough these studies have performed well in technological innovation, they are less integrated in the disciplines of related research. This paper will use multidisciplinary research methods to carry out the improved design research of a patient lift, and carry out the structural design on the basis of user needs. Axiomatic design (AD) is a normative engineering design theory, which can provide a systematic basis for design decisions [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. The concept of contradiction in TRIZ is similar to the coupling design in AD, the so-called coupling, that is, the adjustment of a design parameter, will affect multiple functional requirements variables at the same time [24][25], and the two have inherent consistency and compatibility. Through the relevant tools of TRIZ, the coupling design can be transformed into uncoupled or decoupled design [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. By combining AD with TRIZ, the transformation of demand-function-structure contradiction is realized, and the contradiction analysis method is used to solve the problem objectively and accurately. The method of using AD and TRIZ to solve the problems encountered in product innovation has been applied in many fields. Combined with the concept of modular design, Yang et al.used AD to decompose the function and structure of the shield machine tool changer robot, and use TRIZ to solve the design contradiction [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e27\u003c/span\u003e].Xiao et al.designed a new type of giant SBM cutterhead, TRIZ tools were used to eliminate engineering conflicts in the design process and generate innovative ideas firstly, then based on the independence axiom in AD, functional requirements and design parameters were decomposed. [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Although these methods are feasible in various cases, the AD-TRIZ combination method has not been applied to the design of aging-friendly lift and transfer assist devices. There is a research gap in applying this method to the decision-making and evaluation system of patient lift transfer device design to meet the needs of different users [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn summary, the current research on the design of similar products mainly focuses on the optimization of mechanical structure or only focuses on the analysis of user needs, and lacks systematic design decision-making and evaluation methods of multidisciplinary integration. In order to optimize these problems, this study takes patient lift as the research center, and the research perspective is comprehensive and interdisciplinary. It aims to improve the use experience of household patient lift devices, help the innovative development of household patient lift transfer devices, and provide theoretical basis and case reference for the innovation research of related products.\u003c/p\u003e"},{"header":"2 Axiomatic design(AD)","content":"\u003cp\u003eAD is devoted to enhancing the logic in the process of design scheme generation, and has significant theoretical advantages in conceptual decision-making. It can effectively decompose and hierarchically define the goal of the overall system in product design [30][\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. The Independent Axiom(IA) in the AD requires that the role and function of each product component in the product system in the design scheme are as independent as possible, that is, to try to ensure that the functions of the product components do not affect each other. When using the IA, it is necessary to construct the mapping relationship between function and structure and judge the coupling of the design matrix. According to Eq.\u0026nbsp;\u003cspan refid=\"Equ1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, it is judged whether the design matrix is coupled [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e32\u003c/span\u003e].In the figure, ' X ' indicates that the design parameters have an impact on the functional requirements, and ' O ' indicates that the design parameters have no effect on the functional requirements. Through AD, user needs can be transformed into specific product functions, and the contradiction between function and structure can be constructed and analyzed by using IA.\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:\\begin{array}{c}\\left[A\\right]=\\left[\\begin{array}{ccc}X\u0026amp;\\:0\u0026amp;\\:0\\\\\\:0\u0026amp;\\:X\u0026amp;\\:0\\\\\\:0\u0026amp;\\:0\u0026amp;\\:X\\end{array}\\right]\\left[A\\right]=\\left[\\begin{array}{ccc}X\u0026amp;\\:0\u0026amp;\\:0\\\\\\:0\u0026amp;\\:X\u0026amp;\\:0\\\\\\:X\u0026amp;\\:X\u0026amp;\\:X\\end{array}\\right]\\left[A\\right]=\\left[\\begin{array}{ccc}X\u0026amp;\\:0\u0026amp;\\:X\\\\\\:0\u0026amp;\\:X\u0026amp;\\:X\\\\\\:X\u0026amp;\\:X\u0026amp;\\:X\\end{array}\\right]\\\\\\:\\text{(}\\text{a}\\text{)}\\text{U}\\text{n}\\text{c}\\text{o}\\text{u}\\text{p}\\text{l}\\text{e}\\text{d}\\text{}\\text{d}\\text{e}\\text{s}\\text{i}\\text{g}\\text{n}\\text{}\\text{(}\\text{b}\\text{)}\\text{Q}\\text{u}\\text{a}\\text{s}\\text{i}\\text{-}\\text{c}\\text{o}\\text{u}\\text{p}\\text{l}\\text{i}\\text{n}\\text{g}\\text{}\\text{d}\\text{e}\\text{s}\\text{i}\\text{g}\\text{n}\\text{(}\\text{c}\\text{)}\\text{C}\\text{o}\\text{u}\\text{p}\\text{l}\\text{i}\\text{n}\\text{g}\\text{}\\text{d}\\text{e}\\text{s}\\text{i}\\text{g}\\text{n}\\end{array}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"3TRIZ","content":"\u003cp\u003eTRIZ is an effective method to develop new systems (technologies). It can be used for product function modeling, analysis of functional relationships between product components, and help designers understand product structure and functional principles. It has incomparable advantages in solving problems and innovation [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. In functional modeling, products and product components are defined by systems and components, and the environment, people and things that interact with products are defined as super-system components. Functional modeling decomposes the structure and function of the product through product component analysis and component function analysis. Finally, the functional model diagram is used to illustrate the relationship between product components, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The functional modeling of the product is helpful for the designer to understand the structure principle of the product and lay the foundation for the product optimization.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eUsing contradiction to define problems and using contradiction matrix to solve problems is one of the most commonly used methods in TRIZ [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. TRIZ defines two kinds of contradictions, namely technical contradiction and physical contradiction. When the technical contradiction occurs, the change of a certain attribute in the system will lead to the deterioration of other attributes. When the physical contradiction occurs, the same parameter in the system will not exist at the same time under different needs [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. The design elements are transformed into the corresponding general engineering parameters, and the invention principles of solving problems can be found by comparing the contradiction matrix table. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e is the general engineering parameters defined in TRIZ, and Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e is the inventive principles provided by TRIZ [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e37\u003c/span\u003e][\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eGeneral engineering parameters of TRIZ\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEngineering parameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eEngineering parameter\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWeight of moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePower\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWeight of non-moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eWaste of energy\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLength of moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eWaste of substance\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLength of non-moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLoss of information\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eArea of moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eWaste of time\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eArea of non-moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAmount of substance\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVolume of moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eReliability\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVolume of non-moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAccuracy of measurement\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSpeed\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAccuracy of manufacture\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eForce\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHarmful factors acting on object\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTension/pressure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHarmful side effects\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eShape\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eManufacturing\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStability of object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eConvenience of use\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStrength\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eReparability\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDurability of moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdaptability\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDurability of non-moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eComplexity of device\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTemperature\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eComplexity of control\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBrightness\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLevel of automation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEnergy spent by moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eProductivity\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEnergy spent by non-moving object\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eInvention principles of TRIZ\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePrinciple\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePrinciple\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSegmentation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSkipping\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTaking out\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBlessing in disguise\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLocal quality\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eFeedback\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAsymmetry\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eIntermediary\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMerging\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSelf-service\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUniversality\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eCopying\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNested doll\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eCheap short-living object\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAnti-weight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMechanics substitution\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePreliminary anti-action\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePneumatics and hydraulics\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePreliminary action\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eFlexible shells and thin films\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBeforehand cushioning\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePorous materials\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEquipotentiality\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eColor changes\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eThe other way round\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHomogeneity\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSpheroidality-curvature\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eDiscarding and recovering\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDynamics\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eParameter change\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePartial or excessive actions\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePhase transition\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAnother dimension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eThermal expansion\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMechanical vibration\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eStrong oxidants\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePeriodic action\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eInert atmosphere\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eContinuity of useful action\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eComposite materials\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe path of TRIZ to solve the problem is to abstract the specific problems to be solved into general problems [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. The rational use of contradiction matrix can effectively solve the function-structure contradiction in product design. The general process is to use the above TRIZ tools to transform the elements in the product function-structure contradiction into general engineering parameters, analyze the improved parameters and corresponding deterioration parameters, draw the Archie Schuler conflict matrix, find the appropriate invention principle, optimize and adjust the existing product structure, and finally complete the product design based on the innovative structure.\u003c/p\u003e"},{"header":"4 Design process framework","content":"\u003cp\u003eIn this study, the research process is divided into three parts by means of multidisciplinary combination. Firstly, the TRIZ functional modeling is used to construct the function model of the patient lift and analyze the function structure. Secondly, the function-structure matrix of the device is constructed based on the IA in the AD and the contradiction between function and structure is analyzed. The contradiction analysis method in TRIZ is used to transform the elements in the function-structure contradiction into structural optimization design and verified by computer simulation. After the verification results are obtained, the appearance design of the patient lift is completed based on the best scheme of structural design. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e summarizes the research structure of this paper.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"5 Functional structure analysis based on TRIZ","content":"\u003cp\u003ePatient lift transfer chair is a kind of household patient lift device with high popularity. This paper focuses on the design and research of manual patient lift transfer chair which is suitable for use in home environment. Based on the typical products in the market, its structure is analyzed, and the functional modeling analysis framework in TRIZ is applied to construct the function model of the chair, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eAccording to the product function model, the component analysis of the chair is carried out. The chair is composed of backrest, joystick, armrest, seat plate, cushion, lifting mechanism (including outer pipe, bearing, screw, threaded pipe and other components), backrest lock, bracket lock, bracket, basin frame, basin, base, pedal, universal wheel, foot brake, directional wheel and other system components. In the process of use, it is necessary to interact with the elderly, nursing staff and the ground. Therefore, the elderly, nursing staff and the ground are super system components. The functional relationship between the components is analyzed, and the functional types (basic function, auxiliary function and harmful function) and functional levels (normal, insufficient and excessive) are judged, as shown in Table\u0026nbsp;3.\u003c/p\u003e\u003cp\u003e\u003cb\u003eTable.3\u003c/b\u003e Component function analysis table\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFunctional Carrier\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFunction\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eObject\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eFunction Type\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eFunction Level\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBackrest Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eElderly\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLift Control Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLifting Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSeat Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eElderly\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003eLifting Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLift\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLift Control Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAuxiliary Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLift\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePush Handle Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLift\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSeat Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLift\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSanitation Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAuxiliary Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eSafety Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLock\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBackrest Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLock\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSupport Frame Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eSupport Frame Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBackrest Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFix\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSeat Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHealth module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eService\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eElderly\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eBase Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLifting Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFix\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eFootrest Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eConnect\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMobility Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFootrest Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eElderly\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMobility Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMove\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBase Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"8\" rowspan=\"9\"\u003e\u003cp\u003eCaregiver\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOpen/Close\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBackrest Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePush\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBackrest Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAuxiliary Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOpen/Close\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSeat Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOpen/Close\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSupport Frame Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLift Control Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLock\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSafety Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eClean\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSanitation Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePush\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePush Handle Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMove\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eElderly\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGround\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMobility Module\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGround\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSupport\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eCaregiver\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBasic Function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAccording to the component function analysis table, the function model diagram of the shift machine is drawn. In this study, the function model of the chair is mainly drawn with the elderly as the analysis target, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"6 Contradiction analysis based on AD","content":"\u003cp\u003eBased on the function model diagram drawn by TRIZ modeling analysis, the functional structure of the chair is listed. Using the IA in AD, the mapping relationship between the functional requirements and the structure is constructed. As shown in Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e4\u003c/span\u003e, FR (Function Requirements) represents the functional requirements of the product, and DP (Design Parameters) represents the corresponding product structure [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e40\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMapping relationship between functional requirements and design parameters\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFunctional Requirements (FR)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDesign Parameters (DP)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStable and sturdy body (FR\u003csub\u003e1\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrame structure (DP\u003csub\u003e1\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSafe protective facilities (FR\u003csub\u003e2\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eProtective facilities (DP\u003csub\u003e2\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSensitive braking (FR\u003csub\u003e3\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBrake structure (DP\u003csub\u003e3\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStrong load-bearing capacity (FR\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrame material (DP\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eReasonable size of the transfer device (FR\u003csub\u003e5\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrame structure (DP\u003csub\u003e5\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eReasonable lifting range (FR\u003csub\u003e6\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLifting structure (DP\u003csub\u003e6\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eReduce space occupied during transfer operations (FR\u003csub\u003e7\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOptimized auxiliary transfer structure (DP\u003csub\u003e7\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRust-proof materials (FR\u003csub\u003e8\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrame material (DP\u003csub\u003e8\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAesthetically pleasing (FR\u003csub\u003e9\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAppearance of the transfer device (DP\u003csub\u003e9\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeight adjustment function (FR\u003csub\u003e10\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLifting structure (DP\u003csub\u003e10\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmooth movement and easy steering (FR\u003csub\u003e11\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWheels (DP\u003csub\u003e11\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAuxiliary transfer function (FR\u003csub\u003e12\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOpen-close seat plate structure (DP\u003csub\u003e12\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAuxiliary lifting function (FR\u003csub\u003e13\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAuxiliary lifting structure (DP\u003csub\u003e13\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eReduce the weight of the transfer device (FR\u003csub\u003e14\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrame material (DP\u003csub\u003e14\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eImprove seating comfort (FR\u003csub\u003e15\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSeat material (DP\u003csub\u003e15\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAdjustable toilet opening size (FR\u003csub\u003e16\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eToilet opening structure (DP\u003csub\u003e16\u003c/sub\u003e)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThen, the interaction between functional requirements and design parameters is further analyzed, and the design matrix is listed, as shown in Eq.\u0026nbsp;\u003cspan refid=\"Equ2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. In the formula, ' X ' indicates that the design parameters have an effect on the functional requirements, and ' O ' indicates that the design parameters have no effect on the functional requirements.\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:\\left\\{\\begin{array}{c}F{R}_{1}\\\\\\:F{R}_{2}\\\\\\:F{R}_{3}\\\\\\:F{R}_{4}\\\\\\:F{R}_{5}\\\\\\:F{R}_{6}\\\\\\:F{R}_{7}\\\\\\:F{R}_{8}\\\\\\:F{R}_{9}\\\\\\:F{R}_{10}\\\\\\:F{R}_{11}\\\\\\:F{R}_{12}\\\\\\:F{R}_{13}\\\\\\:F{R}_{14}\\\\\\:F{R}_{15}\\\\\\:F{R}_{16}\\end{array}\\right\\}=\\left[\\begin{array}{cccccccccccccccc}X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\\\\\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\\\\\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\u0026amp;\\:O\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:X\\\\\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:O\u0026amp;\\:X\\end{array}\\right]\\bullet\\:\\left\\{\\begin{array}{c}D{P}_{1}\\\\\\:D{P}_{2}\\\\\\:D{P}_{3}\\\\\\:D{P}_{4}\\\\\\:D{P}_{5}\\\\\\:D{P}_{6}\\\\\\:D{P}_{7}\\\\\\:D{P}_{8}\\\\\\:D{P}_{9}\\\\\\:D{P}_{1O}\\\\\\:D{P}_{11}\\\\\\:D{P}_{12}\\\\\\:D{P}_{13}\\\\\\:D{P}_{14}\\\\\\:D{P}_{15}\\\\\\:D{P}_{16}\\end{array}\\right\\}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAfter analyzing the coupling of the design matrix, the following functional-structural contradictions are obtained: the contradiction between the body stability (FR\u003csub\u003e1\u003c/sub\u003e) and the frame material (DP\u003csub\u003e4\u003c/sub\u003e), the contradiction between body stability (FR\u003csub\u003e1\u003c/sub\u003e) and retractable seat structure (DP\u003csub\u003e7\u003c/sub\u003e), the contradiction between the strong bearing capacity (FR\u003csub\u003e4\u003c/sub\u003e) and the retractable base plate structure (DP\u003csub\u003e7\u003c/sub\u003e), reduce the contradiction between the shift operation space (FR\u003csub\u003e7\u003c/sub\u003e) and the retractable seat structure (DP\u003csub\u003e7\u003c/sub\u003e), improve the contradiction between seat comfort (FR\u003csub\u003e15\u003c/sub\u003e) and retractable seat plate structure (DP\u003csub\u003e7\u003c/sub\u003e), the contradiction between the size adjustment function of the hole (FR\u003csub\u003e16\u003c/sub\u003e) and the retractable seat plate structure (DP\u003csub\u003e7\u003c/sub\u003e).\u003c/p\u003e\u003cp\u003eThrough in-depth analysis of these contradictions, the structural optimization design of the chair can be carried out.\u003c/p\u003e"},{"header":"7 Structural optimization design based on TRIZ","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e7.1 Contradiction resolution\u003c/h2\u003e\u003cp\u003eBased on the function-structure contradiction obtained from the above analysis, the factors that need to be improved and the factors that may deteriorate in each group of contradictions are further analyzed :\u003c/p\u003e\u003cp\u003e(1) The contradiction between body stability (FR\u003csub\u003e1\u003c/sub\u003e) and frame material (DP\u003csub\u003e4\u003c/sub\u003e). The stability of the body requires high strength of the frame material, but the high strength of the frame material will increase the weight of the body, which is contradictory to the functional requirements of reducing the weight of the chair.\u003c/p\u003e\u003cp\u003e(2) The contradiction between body stability (FR\u003csub\u003e1\u003c/sub\u003e) and retractable seat structure (DP\u003csub\u003e7\u003c/sub\u003e). The retractable seat plate structure has the function of auxiliary transfer, but it will affect the stability and safety of the body.\u003c/p\u003e\u003cp\u003e(3) The contradiction between strong load-bearing capacity (FR\u003csub\u003e4\u003c/sub\u003e) and retractable base plate structure (DP\u003csub\u003e7\u003c/sub\u003e). The retractable seat plate is fixed by safety lock and other devices, which will affect the bearing capacity of the chair to a certain extent.\u003c/p\u003e\u003cp\u003e(4) Reduce the contradiction between the transfer operation space (FR\u003csub\u003e7\u003c/sub\u003e) and the retractable seat structure (DP\u003csub\u003e7\u003c/sub\u003e). Retractable seating plates can help transfer in existing products, but need to occupy a larger lateral space when fully deployed.\u003c/p\u003e\u003cp\u003e(5) Improve the contradiction between seat comfort (FR\u003csub\u003e15\u003c/sub\u003e) and retractable seat plate structure (DP\u003csub\u003e7\u003c/sub\u003e). The structure of the retractable seat plate is affected by the processing, assembly and displacement operation. There is a situation where the seat plates on both sides are not aligned during the opening and closing, which has an impact on the seat comfort.\u003c/p\u003e\u003cp\u003e(6) The contradiction between the hole size adjustment function (FR\u003csub\u003e16\u003c/sub\u003e) and the retractable seat plate structure (DP\u003csub\u003e7\u003c/sub\u003e). The position of the hole is set on both sides of the retractable seat plate, and the retractable seat plate will increase the complexity of the structure of the hole size adjustment.\u003c/p\u003e\u003cp\u003eThe factors that need to be improved and the factors that may deteriorate are extracted and transformed into general engineering parameters in TRIZ, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e5\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eGeneral factor conversion\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eFactors to Improve\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eFactors That May Deteriorate\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eO\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFactors\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGeneral parameter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eFactors\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eGeneral parameter\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBody stability factor\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eStability of object (NO.13)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBody weight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eWeight of non-moving object (NO.2)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAchieving transfer function by adjusting seat plate position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eShape (NO.12)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBody stability\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eStability of object (NO.13)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSeat separates during transfer and merges when seated\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAdaptability(NO.35)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLoad-bearing capacity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eStrength (NO.14)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAssisting in repositioning the elderly\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eForce (NO.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLateral distance when seat plate is fully extended\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eLength of non-moving object (NO.4)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEnsuring alignment of seat plate during opening/closing for improved comfort\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eReliability (NO.27)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eDifficulty in manufacturing open-close seat plate structure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eManufacturing (NO.32)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eToilet opening size adjustment mechanism\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eArea of non-moving object(NO.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eComplexity of toilet opening structure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eComplexity of device (NO.36)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe general parameters obtained from the conversion in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e5\u003c/span\u003e are combined with the Archie Schuler conflict matrix table to find the number of the invention principles corresponding to the intersection of the improved parameters and the deteriorated parameters, and Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e6\u003c/span\u003e is sorted out. By comparing the obtained invention principles with the design objectives of the chair, the invention principles of No.1, No.2, No.8, No.10, No.15 and No.40 were finally selected as the guiding method for the design of the patient lift transfer chair, and the structural optimization design was carried out.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eInvention principle\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eImproved parameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"6\" nameend=\"c7\" namest=\"c2\"\u003e\u003cp\u003eDeterioration parameters\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWeight of non-moving object(NO.2)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLength of non-moving object(NO.4)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eStability of object(NO.13)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eStrength(NO.14)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eManufacturing(NO.32)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eComplexity of device(NO.36)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eArea of non-moving object(NO.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e30,2,14,18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e26,7,9,39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2,38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e40,16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e1,18,36\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eForce(NO.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e18,13,1,28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e28,10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e35,10,21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e35,10,14,27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e15,37,18,1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e26,35,10,18\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eShape(NO.12)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e15,10,26,3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e13,14,10,7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e33,1,18,4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e30,14,10,40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1,32,17,28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e16,29,1,28\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStability of object(NO.13)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e26,39,1,40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e/\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e17,9,15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e35,19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e2,35,22,26\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eReliability(NO.27)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3,10,8,28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e15,29,28,11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e/\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e11,28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e/\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e13,35,1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe specific components of the chair include seat module, toilet hole adjustment module, seat lifting module, armpit lifting module and moving module. The following is the structural optimization design of each module.\u003c/p\u003e\u003cp\u003e(1) Structure optimization of armpit lifting module\u003c/p\u003e\u003cp\u003eBased on the principle of invention No.10, the principle of pre-action, pre-placed objects, so that it can play a role in the most convenient position. Then, based on the principle of invention No.8, the principle of weight compensation, a certain object is combined with another object that can provide lift to compensate its weight. According to the above two invention principles, a hydraulic rod is designed to provide lift for the armpit to lift the elderly so that their hips can leave the bed surface, and then the seat is moved under the elderly. After the seat is fixed, the elderly are placed on the seat to complete the transfer operation. This kind of operation process will reduce the physical burden of nursing staff and the elderly, and at the same time facilitate the behavior of the elderly, such as wearing and taking off their pants when they go to the toilet.\u003c/p\u003e\u003cp\u003eThe optimized armpit lifting module is fixedly connected to the seat lifting module. The lifting principle is as follows : the nursing staff adjusts the length of the hydraulic rod by pressing the control handle. When the hydraulic rod becomes longer, the bracket will rotate counterclockwise around the rotation axis, and the height of the armpit will decrease. When the hydraulic rod becomes shorter, the support will have a tendency to rotate clockwise around the rotation axis, and the height of the armpit will rise.\u003c/p\u003e\u003cp\u003e(2) Seat module structure optimization\u003c/p\u003e\u003cp\u003eBased on the principle of invention No.1, the principle of segmentation, an object is divided into independent parts. Then, based on the principle of invention No.2, the extraction principle, parts or attributes that have a negative impact are extracted from the object. According to the above two invention principles, the seat is separated from the main body of the chair and becomes a separate component. First, the ' separated ' attributes of the seat plate are extracted to make the seat a whole, which does not need to occupy a large lateral space when used, and also improves comfort. The ' bilateral ' attribute is extracted and the single-axis lifting is used to avoid the inconsistency of the height on both sides.\u003c/p\u003e\u003cp\u003eThe seat module no longer uses the retractable seat plate and the backrest, and is separated from the main body of the lift frame to become an independent component. When used, it is installed on the seat lifting module by means of plug-in.\u003c/p\u003e\u003cp\u003e(3) Structure optimization of the toilet hole adjustment module\u003c/p\u003e\u003cp\u003eBased on the principle of invention No.15, the dynamic principle, the performance of the object or environment is adjusted to achieve the optimal state in each stage of the work. According to this invention principle, the structure of the hole is optimized to improve the comfort of the seat, and the size adjustment mechanism is designed to make the hole open when needed and close when not needed, which can make the lift better suitable for sitting and resting. The elderly can sit on the chair for a long time.\u003c/p\u003e\u003cp\u003eWith the help of the iris structure, the adjustment of the size of the hole is realized. The toilet hole adjustment module is installed inside the seat module. The adjustment principle is as follows: the nursing staff rotates the control handle, and the driving rod drives the movable pin to move in the driving limit ring, thereby driving the panel to move, so as to realize the function of adjusting the size of the hole.\u003c/p\u003e\u003cp\u003e(4) Material optimization\u003c/p\u003e\u003cp\u003eBased on the principle of invention No.40, the principle of composite materials, composite materials are used instead of homogeneous materials to improve the problem that metal materials are the main components of the frame, seat plate and backrest of the current transfer machine, which leads to the overweight of the product. During the design process, the non-load-bearing parts can be replaced with other materials to reduce the weight of the chair.\u003c/p\u003e\u003cp\u003eAfter the comprehensive application of the above invention principles, the structure of the patient lift transfer chair is shown in Fig.\u0026nbsp;5. In terms of product function, the design scheme has three main advantages compared with various types of patient lift transfer chairs on the market. First of all, this chair can lift the elderly more easily, reduce the manual labor of the nursing staff when assisting the elderly to move, and also reduce the difficulty of the elderly to get up. Secondly, this chair can help the elderly wear pants more easily by hydraulic lifting when assisting the elderly to go to the toilet. Finally, this chair can not only ensure the comfort of the elderly when they are sitting and resting, but also provide convenience for the elderly to go to the toilet by adjusting the size of the toilet hole on the seat surface.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e7.2 Structure simulation\u003c/h2\u003e\u003cp\u003eIn order to verify the safety of the chair structure, the main structure of the chair is simulated and verified.\u003c/p\u003e\u003cp\u003eBecause the density of high carbon steel and stainless steel is greater than that of aluminum alloy, the weight of the main structural material of the chair is large. Therefore, the selection range is reduced to aluminum alloy. Finally, 6061-T6 aluminum alloy with excellent comprehensive performance and wide application is determined. Its yield strength is usually between 240MPa and 300MPa, Poisson 's ratio is about 0.3, and elastic modulus is about 60GPa. In the method of safety inspection, Hu et al.have used SolidWorks simulation and ABAQUS finite element model simulation [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e41\u003c/span\u003e][\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. In this study, the model file is saved in igs format and imported into Ansys Workbench 19.0 for static analysis. After the meshing is completed, a force of 1000N is applied to the chair surface, and the constraint of the contact between the chair leg and the ground is set. Finally, the simulation solution is carried out. The yield strength of the aluminum alloy is set to 280MPa, the Poisson 's ratio is set to 0.3, and the elastic modulus is set to 60GPa to analyze the stress of the main structure of the chair. The simulation results are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e6\u003c/span\u003e. The equivalent stress diagram shows that there is no stress area exceeding 280MPa in the main structure of the fuselage, and the maximum stress is 173.03MPa. Therefore, the main structure of the chair is reasonable and can bear at least 100kg, which meets the needs of most users.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"8 Overall design of patient lift transfer chair","content":"\u003cp\u003eThe chair needs to be used in conjunction with furniture such as beds, sofas, toilets, etc. It also requires frequent access to relatively narrow spaces such as toilets. Therefore, according to the basic human body size data, as well as space size data such as furniture and toilets, the product size of the chair is determined, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e7\u003c/span\u003e. The main reference design standards are ' Chinese adult body size ' ( GB / T 1000\u0026ndash;2023 ) and ' main size of furniture bed ' ( GB / T 3328\u0026thinsp;\u0026minus;\u0026thinsp;2016 ).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSurvey of dimensions affecting the use of lifts\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSize category\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSize category(mm)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDimension requirement(mm)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBed height\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e400\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eH\u003csub\u003eMaximum seat surface\u003c/sub\u003e\u0026ge;650\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMattress\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e200\u0026ndash;250\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSofa / Couch\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e350\u0026ndash;420\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eH\u003csub\u003eMinimum seat surface\u003c/sub\u003e\u0026ge;350\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eToilet\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e350\u0026ndash;400\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUnder-bed clearance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e120\u0026ndash;180\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eH\u003csub\u003eBottom\u003c/sub\u003e\u0026le;120\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBathroom door width\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e600\u0026ndash;700\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eW\u003csub\u003eFuselage\u003c/sub\u003e\u0026le;600\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale chest width\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e330\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eW\u003csub\u003eChest bracket\u003c/sub\u003e=330\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale chest width\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e319\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale shoulder width\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e408\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eW\u003csub\u003eAxillary support\u003c/sub\u003e=385\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale shoulder width\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e378\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAccording to the survey size, the height of most beds is 400mm, and the height of mattresses is between 200mm and 250mm. Therefore, the maximum height of the chair seat surface H\u003csub\u003eMaximum seat surface\u003c/sub\u003e\u0026ge;650mm, the height of the sofa is between 350-420mm, and the height of the toilet is between 350-400mm. Therefore, the minimum height of the seat surface of the chair is determined to be H\u003csub\u003eMinimum seat surface\u003c/sub\u003e\u0026ge;350mm. The gap distance under the bed is generally 120-180mm, so the bottom height of the chair is H\u003csub\u003eBottom\u003c/sub\u003e\u0026le;120mm. The width of the toilet door is generally 600-700mm, so the body width of the chair is W\u003csub\u003eFuselage\u003c/sub\u003e\u0026le; 600mm. According to the national standard of Chinese adult body size GB / T 10000\u0026thinsp;\u0026minus;\u0026thinsp;2023, the 95th percentile sizes of chest width and shoulder width of adult males aged 61\u0026ndash;70 are 330mm and 408mm, respectively, while the sizes of adult females aged 61\u0026ndash;70 are 319mm and 378mm, respectively. Based on the above data research, the height adjustment range of the chair\u0026rsquo;s seat surface is set to 350\u0026ndash;700 mm, the bottom height is 95 mm, the widest part of the lift transfer chair is 57mm, the chest width is 330mm, and the armpit spacing is 385mm. The final appearance effect and three-dimensional size of the product are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e7\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe modeling design and color selection of the lift transfer chair are mainly based on the home environment and the product attributes of medical assistance. The home use scenario of the lift is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e8\u003c/span\u003e. The modeling of this chair avoids too complicated design, but mainly focuses on simple and smooth lines. Through the cutting of the cube and the division of the block surface, the modern sense of the design is increased, which reflects the professionalism of the equipment and can also adapt to most of the home environment. In the choice of color, the design scheme with blue, gray as the main color. Blue gives people a sense of quiet, trust and professionalism, and is suitable for medical and rehabilitation equipment. Gray represents stability, elegance and sense of technology, and enhances the professional image of the product.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eIn order to ensure the high strength and light weight of the seat, PP material with low density, light weight, good mechanical properties, low production cost, fast and accurate production is selected as the material of the seat. The armpit and chest support are filled with sponge. This material has good elasticity and air permeability, which can provide comfortable support while reducing friction and discomfort. The hydraulic control handle is made of rubber material, and the surface is designed with anti-skid texture.\u003c/p\u003e\u003cp\u003eThe transfer operation steps of this chair are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e9\u003c/span\u003e. First of all, the nursing staff moves the chair to the bed, and steps on the brake. The second step, the nursing staff adjusts the rotating handle, the chair to the appropriate height. The third step, the nursing staff controls armpit lift through the handle. In the fourth step, the nursing staff puts the armpit under the armpit of the elderly and then lifts the armpit. The fifth step, the nursing staff gets to install the seat on the chair. The sixth step, the nursing staff controls the armpit to drop the elderly on the seat.\u003c/p\u003e\u003cp\u003eThe operation steps of using this chair to go to the toilet are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e10\u003c/span\u003e. First, the nurse pushes the chair over the toilet. In the second step, the nursing staff adjusts the height of the chair so that the seat can stay on the toilet. The third step, the nursing staff adjusts the size of the toilet hole through the handle on the side of the seat. The fourth step, in the process of toileting, the nursing staff uses the armrest to lift the elderly and assists the elderly to wear pants.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"9 Results And Discussion","content":"\u003cp\u003eTaking the innovative design of household patient lift device for the disabled elderly as an example, the feasibility of the design is verified. The design of age-appropriate patient lift devices based on AD-TRIZ combination method needs to consider a variety of factors, and the process is complex [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e43\u003c/span\u003e]. The research results show that the qualitative and quantitative research on the potential needs of the disabled elderly is carried out by using the AD, TRIZ invention principle and other theoretical methods. The qualitative and quantitative factors are integrated in the design of the lift transfer chair, and the decision-making process becomes more scientific and balanced. The improvement of its overall performance is mainly divided into four aspects: human-machine relationship, operation steps, effort saving and space requirements.\u003c/p\u003e\u003cp\u003eIn addition, the decision to integrate multiple disciplines greatly improves the feasibility of the solution and supports the results of previous studies. For example, through the combination of QFD and AHP, Chen et al.explored the research and development strategy of furniture laminated wood-based panels, providing a reference for the future application of similar environmentally friendly materials [44]. By integrating the Unified Theory of Acceptance and Use of Technology(UTAUT) and the Task-Technology Fit(TTF) model, Wang et al.developed and empirically tested a model to gain a deeper understanding of consumer acceptance of healthy wearable devices(HWDs)[\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. Yu et al.adopted the AHP-CRITIC-TOPSIS method to try to arouse the attraction of Chinese Funan wicker home furnishing products to young consumers in the Chinese market [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. Xie et al.proposed an evaluation method based on AHP fusion gray correlation analysis(GCA ) to propose a green design reference scheme for kindergarten furniture [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e47\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eCompared with previous studies, this study proposes a more novel product design method for patient lift device suitable for the elderly. The functional structure of the patient lift transfer chair is analyzed by using the functional modeling in TRIZ. The mapping relationship between the function and structure of the chair is constructed by establishing the design matrix based on the AD. The contradiction between function and structure is clarified based on the IA. Secondly, the factors that need to be optimized and the factors that may deteriorate in the contradiction are analyzed, and they are transformed into general parameters in TRIZ. With reference to the conflict matrix table of Archie Schuler, the appropriate invention principle is found, and a reasonable structure of the chair is proposed. Ansys Workbench 19.0 software is used to verify the load-bearing capacity of the lift transfer chair, and the final scheme of the optimal design of the chair is improved based on the verified feasible results. This research not only makes a breakthrough in the construction of product structure, but also proves the effectiveness of AD and TRIZ combination method as the guiding framework. In addition, this study also emphasizes multi-dimensional user experience to ensure that the design scheme is more in line with the actual needs, thereby improving the practicability and user satisfaction of the lift transfer chair.\u003c/p\u003e\u003cp\u003eHowever, although significant progress has been made in the integration of related research content disciplines, there are still some limitations in this study. In the analysis of user needs, there is a lack of research on the subjective feelings of the elderly when using displacement aids; the preliminary test was carried out by computer simulation without verifying the strength and safety of the product structure. In addition, it is not possible to further optimize the design scheme through the feedback of market use. Therefore, in the future research, actual users can be invited to conduct qualitative research data to summarize and analyze the user's use characteristics, psychological characteristics and emotional needs, so as to improve the systematic and empirical nature of the research. In addition, in the future, the physical prototype will be made after the design scheme is put forward, so that the optimization of the design scheme will be more comprehensive after the user's actual use experience.\u003c/p\u003e"},{"header":"10 Conclusion","content":"\u003cp\u003eIn this study, AD and TRIZ innovation theory are successively applied to give full play to the complementary advantages of the two theoretical methods, and an interdisciplinary technical route suitable for the design and research of patient lift devices is formed, which effectively makes up for the weak integration of existing related research contents. It provides a clearer, specific and systematic theoretical guidance for the conceptual design process of the whole aging-oriented lift transfer devices, provides case reference for other people 's research, helps future designers to carry out more scientific and systematic design, improves the innovation, feasibility and user satisfaction of the design, promotes the innovation and development of the elderly assistive devices industry, and has made contributions to the cause of social pension. In addition, the research conclusions not only enrich the theoretical and practical research on the design of suitable aging lift transfer chair devices, but also provide a reference method and approach for the conceptual design of other product types. In summary, this study has important theoretical value, practical application value and social significance, but there are also some shortcomings. First of all, there is a lack of research on the subjective feelings of the elderly when using displacement aids, and there is a lack of emotional design in the proposed scheme. Secondly, after the functional structure is proposed, due to the large volume of the product and the lack of corresponding experimental environment, it is impossible to verify the strength and safety of the product structure, and can only be preliminarily tested by computer simulation. After the design scheme is put forward, the prototype and the actual product cannot be made due to the limitation of the actual conditions. The actual use effect of the design scheme has not been verified by experiments, and it cannot be further optimized through the use feedback scheme of the market. Future research can further discuss these technical principles in more detail.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eThe design, implementation, data analysis and conclusion writing of this study were not influenced by any financial sponsors.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eWL conceived the study and was responsible for the overall design and methodology, HR developed the framework ideas and content, WZ wrote the content and charted, and made a significant contribution to the interpretation of the results. HZ and XY participated in the literature review and manuscript preparation. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\u003ch2\u003eData availability\u003c/h2\u003e\u003cp\u003eData sharing is not applicable to this research as no data were generated or analysed.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eZhang X, Han H (2023) Spatiotemporal Dynamic Characteristics and Causes of China\u0026rsquo;s Population Aging from 2000 to 2020. Sustainability 15:7212. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/su15097212\u003c/span\u003e\u003cspan address=\"10.3390/su15097212\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu H, Wang Y, Zhang H et al (2024) An investigation into the health status of the elderly population in China and the obstacles to achieving healthy aging. Sci Rep 14:31123. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-024-82443-2\u003c/span\u003e\u003cspan address=\"10.1038/s41598-024-82443-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTian P, Wang G, Liu, Yaping Z, Juan (2021) Understanding Disabilities among the Elderly in China: Important Factors, Current Situation, and Future Perspective, Discrete Dynamics in Nature and Society, 6665351, 10 pages, 2021. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1155/2021/6665351\u003c/span\u003e\u003cspan address=\"10.1155/2021/6665351\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang T, Zhang B, Liu C, Liu T, Han Y, Wang S, Ferreira JP, Dong W, Zhang X (2022) A Review on the Rehabilitation Exoskeletons for the Lower Limbs of the Elderly and the Disabled. Electronics 11:388. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/electronics11030388\u003c/span\u003e\u003cspan address=\"10.3390/electronics11030388\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi W, Liu K, Li C et al (2022) Development and Evaluation of a Wearable Lower Limb Rehabilitation Robot. J Bionic Eng 19:688\u0026ndash;699. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s42235-022-00172-6\u003c/span\u003e\u003cspan address=\"10.1007/s42235-022-00172-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchoenfisch AL, Kucera KL, Lipscomb HJ, McIlvaine J, Becherer L, James T, Avent (2019) Susan. Use of Assistive Devices to Lift, Transfer, and Reposition Hospital Patients. Nursing Research 68(1):p 3\u0026ndash;12, 1/2 | \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/NNR.0000000000000325\u003c/span\u003e\u003cspan address=\"10.1097/NNR.0000000000000325\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNelson A, Matz M, Chen F, Siddharthan K, Lloyd J, Fragala G (2006) Development and evaluation of a multifaceted ergonomics program to prevent injuries associated with patient handling tasks. Int J Nurs Stud 43:717\u0026ndash;733\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSivakanthan S, Blaauw E, Greenhalgh M, Koontz AM, Vegter R, Cooper, Rory A (2019) Person transfer assist systems: a literature review. Disabil Rehabilitation: Assist Technol 1\u0026ndash;10. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1080/17483107.2019.1673833\u003c/span\u003e\u003cspan address=\"10.1080/17483107.2019.1673833\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVenkat K, Vijay K, K. G A et al (1997) Design and Virtual Prototyping of Rehabilitation Aids[C]//University of Pennsylvania\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStrasser H Compatibility as guiding principle for ergonomics work design and preventive occupational health and safety[J]. Z f\u0026uuml;r Arbeitswissenschaft 2021, 76(3):1\u0026ndash;35\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTian Y et al (2021) Design and Evaluation of a Novel Person Transfer Assist System, in IEEE Access, vol. 9, pp. 14306\u0026ndash;14318. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/ACCESS.2021.3051677\u003c/span\u003e\u003cspan address=\"10.1109/ACCESS.2021.3051677\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBrown CC Patient Lift and Exercise Apparatus: U.S. Patent 3,877,421[P].1975-04-15\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHakamiun R, Genereux DP, Falin MD et al Patient lift: U S Patent 6,289,534[P].2001-09-18.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMartin WE, Barr R Patient Lift Device: U.S. Patent 8,793,822[P].2014-08-05\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhrary A, Yang W-S, Inada M Kazumi Nakamatsu,Development of the Lift Assist Chair for the Elderly People Rakutateru,Procedia Computer Science,131,2018,Pages 31\u0026ndash;37,ISSN 1877\u0026thinsp;\u0026ndash;\u0026thinsp;0509,\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.procs.2018.04.182\u003c/span\u003e\u003cspan address=\"10.1016/j.procs.2018.04.182\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHeacock H, Paris-Seeley N, Tokuno C, Frederking S, Keane B, Mattie J, Kanigan R James Watzke,Development and evaluation of an affordable lift device to reduce musculo-skeletal injuries among home support workers,Applied Ergonomics,35, Issue 4,2004,Pages 393\u0026ndash;399,ISSN 0003-6870, \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.apergo.2004.02.006\u003c/span\u003e\u003cspan address=\"10.1016/j.apergo.2004.02.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSimon Christensen S, Rafique (2021) Shaoping Bai,Design of a powered full-body exoskeleton for physical assistance of elderly people,International Journal of Advanced Robotic Systems,Vol Issue 11, pp. -Issue published date: December-01-2021\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKong YK, Choi KH, Park SS, Shim JW, Shim HH (2023) Evaluation of the Efficacy of a Lift-Assist Device Regarding Caregiver Posture and Muscle Load for Transferring Tasks. Int J Environ Res Public Health 20(2):1174. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/ijerph20021174\u003c/span\u003e\u003cspan address=\"10.3390/ijerph20021174\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003ePMID: 36673934; PMCID: PMC9858700\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu R, Wang J, Chen W, Wang P (2020) Design of a transfer robot for the assistance of elderly and disabled. Adv Robot 35(3\u0026ndash;4):194\u0026ndash;204. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/01691864.2020.1819875\u003c/span\u003e\u003cspan address=\"10.1080/01691864.2020.1819875\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTian Y et al (2021) Design and Evaluation of a Novel Person Transfer Assist System, in IEEE Access, vol. 9, pp. 14306\u0026ndash;14318. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/ACCESS.2021.3051677\u003c/span\u003e\u003cspan address=\"10.1109/ACCESS.2021.3051677\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHumphreys HC, Choi YM, Book WJ (2017) Advanced patient transfer assist device with intuitive interaction control. Assist Technol 35(1):3\u0026ndash;13. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/10400435.2017.1396564\u003c/span\u003e\u003cspan address=\"10.1080/10400435.2017.1396564\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnurag Purwar K, Bhargava Edward Behan,A multi-functional mobility assist device for sit-to-stand motion,International Journal of Industrial Ergonomics,Volume 93,2023,103396,ISSN 0169\u0026ndash;8141,\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ergon.2022.103396\u003c/span\u003e\u003cspan address=\"10.1016/j.ergon.2022.103396\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSuh NP (1995) Designing-in of quality through axiomatic design. IEEE Transactions on Reliability, 44(2): pp. 256\u0026ndash;264. Mann D.Axiomatic design and TRIZ: compatibilities and contradictions [J].TRIZ Journal 1999 4(6):34ཞ39 Mann D.Axiomatic design and TRIZ: compatibilities and contradictions(2) [J].TRIZ Journal 1999 4༈7༉:53ཞ58\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBai Z, Zhang S, ,Ding M et al Research on product innovation design of modularization based on theory of TRIZ and axiomatic design[J]. Adv Mech Eng 2018, 10(12):168781401881408\u0026ndash;168781401881408\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMei Y, Yimin X, ,Lianhui J et al A modular design method based on TRIZ and AD and its application to cutter changing robot[J].Advances in Mechanical Engineering,2021,13(7)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJing X, Feixiang L, ,Mei Y et al An innovative design of mega shaft boring machine (SBM) cutterhead based on TRIZ and AD theory[J].Advances in Mechanical Engineering,2023,15(2)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang T, Zhao Y, ,Zhang X et al Design of walking aids for the elderly based on the Kano-AHP-FEC method[J].Scientific Reports,2025,15(1):2663\u0026ndash;2663\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQihua T, Yixian D, ,Xiangman Z et al Research on Integrated Model of Products' Conceptual Design Based on AD and TRIZ and its Application[C]//国际计算机辅助工业设计与概念设计学术会议主委会.Proceedings of 2011 IEEE 12th International Conference on Computer-Aided Industrial Design \u0026amp; Conceptual Design Vol.2.[出版者不详],2011:370\u0026ndash;373\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOsman Kulak S, Cebi Cengiz Kahraman,Applications of axiomatic design principles: A literature review,Expert Systems with Applications,Volume 37, Issue 9,2010,Pages 6705\u0026ndash;6717,ISSN 0957\u0026ndash;4174,\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.eswa.2010.03.061\u003c/span\u003e\u003cspan address=\"10.1016/j.eswa.2010.03.061\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGon\u0026ccedil;alves-Coelho AM, Neştian G, Cavique M et al (2012) Tackling with redundant design solutions through axiomatic design. Int J Precis Eng Manuf 13:1837\u0026ndash;1843. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s12541-012-0241-x\u003c/span\u003e\u003cspan address=\"10.1007/s12541-012-0241-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eImoh M, Ilevbare D, Probert R, Phaal A review of TRIZ, and its benefits and challenges in practice,Technovation, 33, Issues 2\u0026ndash;3,2013,Pages 30\u0026ndash;37,ISSN 0166\u0026ndash;4972,\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.technovation.2012.11.003\u003c/span\u003e\u003cspan address=\"10.1016/j.technovation.2012.11.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBoxing T, Guohua G, ,Yongzhi L et al (2019) The Innovative Design of Seedling Transplanting Combination Mechanism with TRIZ[J].Journal of Physics: Conference Series,1267012073-012073\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eS\u0026eacute;bastien Dubois, Guio RD, Rasovska I (2013) Resolution of Inventive Problems: Different Kind of Mechanisms[J]. Int J Syst Innov 1(4):2\u0026ndash;10\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSheu D, Daniel (2020) Chiu Ming-Chuan, Cayard Dimitri.The 7 pillars of TRIZ philosophies[J]. Comput Ind Eng 146:106572\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLu S, Guo Y, Huang, Wei (2022) Shen, Min, Product Form Evolutionary Design Integrated with TRIZ Contradiction Matrix, Mathematical Problems in Engineering, 3844324, 12 pages, 2022. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1155/2022/3844324\u003c/span\u003e\u003cspan address=\"10.1155/2022/3844324\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXie Q, Liu Q (2023) Application of TRIZ Innovation Method to In-Pipe Robot Design. Machines 11:912. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/machines11090912\u003c/span\u003e\u003cspan address=\"10.3390/machines11090912\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYan W, Liu H, Zanni-Merk C, Cavallucci D (2015) IngeniousTRIZ: An automatic ontology-based system for solving inventive problems. Knowl Based Syst 75:52\u0026ndash;65. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.knosys.2014.11.015\u003c/span\u003e\u003cspan address=\"10.1016/j.knosys.2014.11.015\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFoley JT Sigr\u0026uacute;n Har\u0026eth;ard\u0026oacute;ttir,Creative Axiomatic Design,Procedia CIRP, Volume 50,2016,Pages 240\u0026ndash;245,ISSN 2212\u0026ndash;8271,\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.procir.2016.04.116\u003c/span\u003e\u003cspan address=\"10.1016/j.procir.2016.04.116\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi S, Hu W (2023) Study on mechanical strength of cantilever handrail joints for chair, BioResources. 18(1):209\u0026ndash;219. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.15376/biores.18.1.209-219\u003c/span\u003e\u003cspan address=\"10.15376/biores.18.1.209-219\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYu R, Liu Y, Konukcu CA, Wengang H (2024) A method of simulating seat load for numerical analysis of wood chair structure. Wood Res 69(3):432\u0026ndash;444. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.37763/wr.1336-4561/69.3.432444\u003c/span\u003e\u003cspan address=\"10.37763/wr.1336-4561/69.3.432444\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang T, Zhao Y, Zhang X et al (2025) Design of walking aids for the elderly based on the Kano-AHP-FEC method. Sci Rep 15:2663. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-025-85540-y\u003c/span\u003e\u003cspan address=\"10.1038/s41598-025-85540-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYushu Chen; Wenwen Sun. R\u0026amp;D Strategy Study of Customized Furniture with Film-Laminated Wood-Based Panels Based on an Analytic Hierarchy Process/Quality Function Deployment Integration Approach[J]. BioResources, (2023) 18(4): 8249\u0026ndash;8263. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.15376/biores.18.4.8249-8263\u003c/span\u003e\u003cspan address=\"10.15376/biores.18.4.8249-8263\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang H, Tao D, Yu N et al (2020) Understanding consumer acceptance of healthcare wearable devices: An integrated model of UTAUT and TTF[J]. Int J Med Informatics 139:104156\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYu S, Zhu Y, Liu F, Zhong Z, Sun J (2024) AHP-CRITIC-TOPSIS-based analysis of the influence of young people\u0026rsquo;s preferences on the design of Funan wicker home products, BioResources 19(4), 8216\u0026ndash;8237\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXie X, Zhu J, Ding S, Chen J (2024) AHP and GCA Combined Approach to Green Design Evaluation of Kindergarten Furniture. Sustainability 16:1. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/su16010001\u003c/span\u003e\u003cspan address=\"10.3390/su16010001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"patient lift, disabled elderly, axiomatic design, TRIZ","lastPublishedDoi":"10.21203/rs.3.rs-6848008/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6848008/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWith the rapid increase of China 's aging population, ensuring the safety of disabled elderly has become a prominent problem. Therefore, it is necessary to optimize the design of disabled elderly household patient lifts. Based on the multidisciplinary integration method, this research optimizes the design of a household patient lift for disabled elderly people. Firstly, the functional structure is analyzed by TRIZ functional modeling, and the function-structure mapping relationship is constructed based on axiomatic design theory(AD). Then TRIZ is used to analyze contradictory problems, find out the invention principle, and propose a reasonable patient lift transfer chair structure. The rationality and safety of the structure are verified by computer simulation, and the appearance design is determined based on the above results. The research results show that the method of integrating AD and TRIZ can effectively guide the design of patient lift products. The design of the chair is reasonable, easy to operate and stable in structure. It can effectively make up for the lack of research in related fields and promote the innovative development of the elderly auxiliary industry.\u003c/p\u003e","manuscriptTitle":"Research on home patient lift transfer chair design of disabled elderly based on AD and TRIZ","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-11 07:15:41","doi":"10.21203/rs.3.rs-6848008/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c84db662-cd11-4ff2-994b-72ea678222b5","owner":[],"postedDate":"August 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":52698290,"name":"Humanities/Health humanities"},{"id":52698291,"name":"Social science/Science technology and society"}],"tags":[],"updatedAt":"2025-09-18T12:08:50+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-11 07:15:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6848008","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6848008","identity":"rs-6848008","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}