Towards a Bathroom-Centered Human-Building Digital Twin Framework for Indoor Safety Analysis
2026-06-22 • Human-Computer Interaction
Human-Computer InteractionArtificial Intelligence
AI summaryⓘ
The authors highlight that bathrooms can be risky for older adults because of things like slippery floors and tight spaces. They say that looking at either the bathroom setup or a person’s movements alone doesn’t fully explain these risks. To fix this, they created a digital model that combines both what’s in the bathroom and how a person moves in it. Their model helps understand how older adults interact with bathroom features and shows potential safety issues. While it’s still a prototype, this approach could help design safer bathrooms for aging people living at home.
Digital TwinHuman-Building InteractionOlder Adult SafetyBathroom HazardsSkeleton-Based Human RepresentationSemantic Environment MappingFall DetectionActivity RecognitionSpatial-Semantic CouplingAging in Place
Authors
Yuanzhi Su, Huiying, Hou
Abstract
Bathroom use is a critical safety challenge for older adults because wet surfaces, constrained layouts, limited support, and frequent posture transitions are concentrated within a small domestic space. These conditions create risks that cannot be adequately understood by considering either the bathroom environment or human motion in isolation. Existing bathroom safety studies mainly identify hazards, accessibility problems, or design modifications, whereas human-centered sensing studies often focus on activity recognition or fall detection without sufficient semantic understanding of the surrounding environment. This separation limits the interpretation of how older adults interact with fixtures, support surfaces, wet areas, and spatial constraints during daily bathroom activities. To address this gap, this study proposes a bathroom-centered human-building digital twin framework for interaction-aware indoor safety analysis with a specific emphasis on older adult bathroom safety. The framework conceptualizes bathroom risk as a coupled human-environment process and integrates semantic bathroom representation, skeleton-based human representation, spatial-semantic coupling, interaction-aware event analytics, and safety-oriented visualization. A Unity-based proof-of-concept prototype is developed to demonstrate the feasibility of the framework. Although the current work remains a prototype-oriented investigation, it establishes a methodological basis for analyzing older adults' bathroom safety through explicit body-environment relations and for advancing privacy-sensitive, interaction-aware digital twin applications in aging-in-place residential environments.