In-home elderly monitoring requires systems that can detect emergency events - such as falls or prolonged inactivity - while preserving privacy and requiring no user input. These systems must be embedded into the surrounding environment, capable of capturing activity, and responding promptly. This paper presents a low-cost, privacy-preserving solution using Passive Infrared (PIR) and Light Detection and Ranging (LiDAR) sensors to track entries, sitting, exits, and emergency scenarios within a home bathroom setting. We developed and evaluated a rule-based detection system through five real-world experiments simulating elderly behavior. Annotated time-series graphs demonstrate the system's ability to detect dangerous states, such as motionless collapses, while maintaining privacy through non-visual sensing.

翻译：居家老年人监护系统需能在保护隐私且无需用户主动交互的前提下，检测紧急事件（如跌倒或长时间静止）。此类系统必须嵌入生活环境，能够捕捉活动状态并及时响应。本文提出一种低成本、隐私保护的解决方案，利用被动红外（PIR）与激光探测与测距（LiDAR）传感器，在家庭浴室场景中追踪进入、就坐、离开及紧急事件。我们通过模拟老年人行为的五项真实场景实验，开发并评估了一套基于规则的检测系统。标注后的时序图表明，该系统能够通过非视觉传感方式在保护隐私的同时，检测危险状态（如静止性跌倒）。