IEEE Trans Biomed Eng. 2021 Nov;68(11):3228-3240. doi: 10.1109/TBME.2021.3066876. Epub 2021 Oct 19.
Over the last two decades, radar-based contactless monitoring of vital signs (heartbeat and respiration rate) has raised increasing interest as an emerging and added value to health care. However, until now, the flaws caused by indoor multipath propagation formed a fundamental hurdle for the adoption of such technology in practical healthcare applications where reliability and robustness are crucial. Multipath reflections, originated from one person, combine with the direct signals and multipaths of other people and stationary objects, thus jeopardizing individual vital signs extraction and localization. This work focuses on tackling indoor multipath propagation.
We describe a methodology, based on accurate models of the indoor multipaths and of the radar signals, that enables separating the undesired multipaths from desired signals of multiple individuals, removing a key obstacle to real-world contactless vital signs monitoring and localization.
We also demonstrated it by accurately measure individual heart rates, respiration rates, and absolute distances (range information) of paired volunteers in a challenging real-world office setting.
The approach, validated using a frequency-modulated continuous wave (FMCW) radar, was shown to function in an indoor environment where radar signals are severely affected by multipath reflections.
Practical applications arise for health care, assisted living, geriatric and quarantine medicine, rescue and security purposes.
在过去的二十年中，基于雷达的非接触式生命体征（心跳和呼吸率）监测作为一种新兴的、对医疗保健有附加值的技术引起了越来越多的关注。然而，直到现在，室内多径传播造成的缺陷仍然是该技术在实际医疗保健应用中采用的一个基本障碍，因为这些应用对可靠性和稳健性有很高的要求。多径反射源于一个人，与其他人的直接信号和多径以及静止物体的多径相结合，从而危及个体生命体征的提取和定位。这项工作专注于解决室内多径传播问题。
我们描述了一种基于室内多径和雷达信号的精确模型的方法，该方法能够将不需要的多径与多个个体的期望信号分离，从而消除了非接触式生命体征监测和定位的一个关键障碍。
我们还通过在具有挑战性的现实办公室环境中对配对志愿者进行精确测量个体心率、呼吸率和绝对距离（距离信息）来证明了这一点。
该方法使用调频连续波（FMCW）雷达进行了验证，在雷达信号受到多径反射严重影响的室内环境中，该方法能够正常工作。
该方法为医疗保健、辅助生活、老年医学和检疫医学、救援和安全目的提供了实际应用。
