Compact Design of A Lightweight Rehabilitative Exoskeleton for Restoring Grasping Function in Patients with Hand Paralysis

Abstract BackgroundMillions of individuals suffer from upper extremity paralysis caused by neurological disorders including stroke, traumatic brain injury, spinal cord injury, or other medical conditions. In order to restore motor control and enhance the quality of life of these patients, daily exercises and strengthening training are necessary. Robotic hand exoskeletons can substitute for the missing motor control and help to restore the functions performed in daily operations. They can also facilitate neuroplasticity to help rehabilitate hand function through routine use. However, most of the hand exoskeletons are bulky, stationary, and cumbersome to use.Methods We have utilized a recent design of a hand exoskeleton (Tenoexo) and modified the design to prototype a motorized, lightweight, fully wearable rehabilitative hand exoskeleton by combining rigid parts with a soft mechanism capable of producing various grasps needed for the execution of daily tasks. We have tested the performance of our developed hand exoskeleton in restoring hand functions in two quadriplegics with chronic cervical cord injury.ResultsMechanical evaluation of our exoskeleton showed that it can produce fingertip force up to 8 N and can cover 91.5 degree of range of motion in just 3 seconds. We further tested the robot in two quadriplegics with chronic hand paralysis, and observed immediate success on independent grasping of different daily objects. ConclusionsThe results suggest that our exoskeleton is a viable option for hand function assistance, allowing patients to regain lost finger control for everyday activities.