Radar Sensing of Vital Signs in Assisted Living Applications

In order to be accepted by users, one of the most important requirement for any assisted living technology is unobtrusiveness. This is particularly true when this technology is intended for continuous monitoring of vital signs, since traditional approaches require the subject to be tethered to measurement devices. The radar sensing is a very promising technology, enabling the measurement of vital signs at a distance, and thus meeting both requirements of unobtrusiveness and accuracy. In particular, impulse-radio ultra-wideband radar has attracted considerable attention in recent years thanks to many properties that make it useful for assisted living purposes. The aim of this paper is to investigate such radar technology for vital signs monitoring in assisted living scenarios. An algorithmic framework for the detection of respiration and heart rates during various activities of daily living is presented, including a method for compensation of movements of both the monitored subject and a second person present in the same environment (e.g., family member, caregiver, etc.). Experiments are carried out in various conditions that can be frequently encountered in assisted living scenarios. The reported results show that vital signs can be detected also while carrying out ADLs, with accuracy varying according to the level of movements and kind of involved body's parts and postures.