Explainable Multimodal Fall Detection via Ontology-Guided Sensor Fusion and Semantic Reasoning

Explainable Multimodal Fall Detection via Ontology-Guided Sensor Fusion and Semantic Reasoning | 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 Research Article Explainable Multimodal Fall Detection via Ontology-Guided Sensor Fusion and Semantic Reasoning Thi Thu Thuy Pham, Chi Thanh Bui This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8242584/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 Falls remain a critical safety concern in elder care, yet existing detection systems often suffer from poor generalization and lack of explainability. This paper introduces a novel ontology-guided multimodal framework that integrates vision-based pose estimation, inertial sensing, and semantic reasoning for accurate and transparent fall detection. Unlike black-box deep learning approaches, our system embeds domain knowledge into an OWL ontology and SWRL rule engine, enabling human-interpretable decision-making. We demonstrate that this hybrid symbolic-subsymbolic architecture not only achieves competitive performance - up to 98.8% accuracy and 0.985 F1-score on benchmark datasets - but also significantly reduces false alarms. Furthermore, our modular design allows for extensibility across domains, including preliminary transfer to mobile trust assessment. We validate the effectiveness of the approach through comparative experiments and share the full source code for reproducibility at https://github.com/thuthuypht/fall_detection_app . This work contributes to the emerging field of knowledge-infused AI, offering a scalable, interpretable, and high-precision solution for safety-critical applications such as elder monitoring. Ontology-Based Reasoning Fall Detection Mobile Health Monitoring IoT Sensor Systems Health Risk Assessment Full Text 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-8242584","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":559492237,"identity":"5b5eb574-9e37-4c1f-ac3f-5cdeceb5af87","order_by":0,"name":"Thi Thu Thuy Pham","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwUlEQVRIiWNgGAWjYDACCQYGZiAlB+GxEaGDR4KBsRlIG0NUk6IlsYFoLfbSPeaPC9sOp2+X7zFg+FB2mMHgdgMBW2TOGDbPbDucu7ONx4BxxjmgljsHCDksx7CZF6hlwzEeA2Ygg0FyRgJxWtINQFr+kqIlAayFEaiFX4KQlhtphbN5zqUbbjiWVnCw51w6D0Et7DOSN3zmKbOWNzh8eOODH2XWcmyEtEBBM5g8ALKWKPVAUEeswlEwCkbBKBiJAAAN5z4+QDeyjAAAAABJRU5ErkJggg==","orcid":"","institution":"Nha Trang University","correspondingAuthor":true,"prefix":"","firstName":"Thi","middleName":"Thu Thuy","lastName":"Pham","suffix":""},{"id":559492238,"identity":"51304846-f2ee-478e-b0a5-b4f64745d2a7","order_by":1,"name":"Chi Thanh Bui","email":"","orcid":"","institution":"Nha Trang University","correspondingAuthor":false,"prefix":"","firstName":"Chi","middleName":"Thanh","lastName":"Bui","suffix":""}],"badges":[],"createdAt":"2025-11-30 14:23:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8242584/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8242584/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98440369,"identity":"6befa2ac-1cc8-4608-b3c0-d49e78863bbb","added_by":"auto","created_at":"2025-12-17 17:03:47","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1373291,"visible":true,"origin":"","legend":"","description":"","filename":"Ontologyfalldedectionv3docx.docx","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/8222549e4a1e07808478c231.docx"},{"id":98369438,"identity":"df0eb59b-283d-4124-9eac-1fda2ef880ce","added_by":"auto","created_at":"2025-12-17 05:10:59","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":4184,"visible":true,"origin":"","legend":"","description":"","filename":"105688f333114b4791a38da5dcf267ce.json","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/b4faa087287be259c0bb209c.json"},{"id":98440407,"identity":"bcccd165-685c-477f-a1d4-2384487300c2","added_by":"auto","created_at":"2025-12-17 17:03:50","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":136587,"visible":true,"origin":"","legend":"","description":"","filename":"105688f333114b4791a38da5dcf267ce1enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/b729300946ceccf3c3be19a8.xml"},{"id":98438628,"identity":"f8f7fd16-82ca-4208-a4ce-1071cf2ef38d","added_by":"auto","created_at":"2025-12-17 16:59:40","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":68864,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/fd8e32d03215aa338e857854.png"},{"id":98440477,"identity":"c8671b1a-a25a-48c9-b922-6db396fddeed","added_by":"auto","created_at":"2025-12-17 17:03:54","extension":"png","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":187196,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/beb128bcbce06eb9e2edd60b.png"},{"id":98369439,"identity":"40236c44-92c5-45d5-97b8-a7049b4c6c40","added_by":"auto","created_at":"2025-12-17 05:10:59","extension":"png","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":190038,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/7fbdd47f626d9a1bac37489a.png"},{"id":98369442,"identity":"8f458f64-3c62-442d-8b3c-deb61958bac3","added_by":"auto","created_at":"2025-12-17 05:10:59","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":249732,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/0ebd7b8a49d7afc8b32f4d88.png"},{"id":98439032,"identity":"7b00b79f-f917-4d6b-8ae9-99dda97e0cdc","added_by":"auto","created_at":"2025-12-17 17:00:46","extension":"jpeg","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":500078,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/cba6ec7511ce970a4491063c.jpeg"},{"id":98440556,"identity":"04d7ac25-26af-45a0-8f0e-a1b7f2ba6b44","added_by":"auto","created_at":"2025-12-17 17:04:00","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":48710,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/1ca0810b58227910ab079653.png"},{"id":98438927,"identity":"d8eee079-eeb0-4ce1-88e4-851e5a6d57ce","added_by":"auto","created_at":"2025-12-17 17:00:29","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64035,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/3cfdde8ac92e89befc79389d.png"},{"id":98440887,"identity":"efc5133b-c2c9-4636-bfc2-52d227a321c5","added_by":"auto","created_at":"2025-12-17 17:04:34","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":52377,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/45e2384ffa7975b45e5df859.png"},{"id":98369446,"identity":"5075739a-a1ee-45d2-a3da-0cecec84d58f","added_by":"auto","created_at":"2025-12-17 05:10:59","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":25828,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/f23cb5cca6ae6d18f2f4e71b.png"},{"id":98369449,"identity":"06719379-5124-4635-b748-d4890b00170e","added_by":"auto","created_at":"2025-12-17 05:10:59","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":32784,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/46f15e37f1b9ed1eff7a9e2f.png"},{"id":98439024,"identity":"4b4a5d18-272d-440a-b6f1-477c57dd0275","added_by":"auto","created_at":"2025-12-17 17:00:45","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":33475,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/714e07adf3a440192f033f81.png"},{"id":98439570,"identity":"c4984752-7f1a-401f-afc2-eb7e16a4eb62","added_by":"auto","created_at":"2025-12-17 17:02:08","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":52697,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/6f3c1ad4db79fdf5cd652f1f.png"},{"id":98439549,"identity":"e6fe5825-e2ed-4e9f-b224-1067433e460e","added_by":"auto","created_at":"2025-12-17 17:02:04","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":218307,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/3ce4dc00139a7d16b2da1684.png"},{"id":98439127,"identity":"2f1c1b6f-01d4-4260-85aa-b84178cb6354","added_by":"auto","created_at":"2025-12-17 17:01:14","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14202,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/95c9ccc30018eaf989ce9b64.png"},{"id":98369452,"identity":"11aedfde-6e8e-40a6-a512-142e913fe7df","added_by":"auto","created_at":"2025-12-17 05:10:59","extension":"png","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":20093,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/e6ffd71c828844c51d0ff3a7.png"},{"id":98369455,"identity":"b0d3517e-c19d-479e-a922-6734bcc8849e","added_by":"auto","created_at":"2025-12-17 05:11:00","extension":"png","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13129,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/07ebca110a36d5c9d84c243c.png"},{"id":98369456,"identity":"43b75fec-9d5e-429d-98de-e130538bdf57","added_by":"auto","created_at":"2025-12-17 05:11:00","extension":"xml","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":131956,"visible":true,"origin":"","legend":"","description":"","filename":"105688f333114b4791a38da5dcf267ce1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/5c97ebf8e3fef6a097a3bd88.xml"},{"id":98369457,"identity":"953a71b5-c7d8-4fe1-b900-546f9d7d9bc0","added_by":"auto","created_at":"2025-12-17 05:11:00","extension":"html","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":155336,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1/2f0d441b6f698d47c7c46c99.html"},{"id":98622556,"identity":"2a22a5ae-d0dc-4984-8801-6948c97731cb","added_by":"auto","created_at":"2025-12-19 16:57:48","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1196501,"visible":true,"origin":"","legend":"","description":"","filename":"Ontologyfalldedectionv3docx.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8242584/v1_covered_1dcd00a7-f44b-41a2-98bb-99d10142bf62.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Explainable Multimodal Fall Detection via Ontology-Guided Sensor Fusion and Semantic Reasoning","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"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":"Ontology-Based Reasoning, Fall Detection, Mobile Health Monitoring, IoT Sensor Systems, Health Risk Assessment","lastPublishedDoi":"10.21203/rs.3.rs-8242584/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8242584/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFalls remain a critical safety concern in elder care, yet existing detection systems often suffer from poor generalization and lack of explainability. This paper introduces a novel ontology-guided multimodal framework that integrates vision-based pose estimation, inertial sensing, and semantic reasoning for accurate and transparent fall detection. Unlike black-box deep learning approaches, our system embeds domain knowledge into an OWL ontology and SWRL rule engine, enabling human-interpretable decision-making. We demonstrate that this hybrid symbolic-subsymbolic architecture not only achieves competitive performance - up to 98.8% accuracy and 0.985 F1-score on benchmark datasets - but also significantly reduces false alarms. Furthermore, our modular design allows for extensibility across domains, including preliminary transfer to mobile trust assessment. We validate the effectiveness of the approach through comparative experiments and share the full source code for reproducibility at \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://github.com/thuthuypht/fall_detection_app\u003c/span\u003e\u003cspan address=\"https://github.com/thuthuypht/fall_detection_app\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. This work contributes to the emerging field of knowledge-infused AI, offering a scalable, interpretable, and high-precision solution for safety-critical applications such as elder monitoring.\u003c/p\u003e","manuscriptTitle":"Explainable Multimodal Fall Detection via Ontology-Guided Sensor Fusion and Semantic Reasoning","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-17 05:10:50","doi":"10.21203/rs.3.rs-8242584/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":"a65ab5e8-5b25-4831-a0e8-27a5b9e6e687","owner":[],"postedDate":"December 17th, 2025","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-23T04:05:39+00:00","index":25,"fulltext":""},{"type":"reviewerAgreed","content":"72716902621527610310307016440152665761","date":"2026-05-18T09:54:02+00:00","index":24,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-17T05:10:50+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-17 05:10:50","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8242584","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8242584","identity":"rs-8242584","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}