Respiration and Heart Rate Monitoring in Smart Homes: An Angular-Free Approach with an FMCW Radar

Abstract

This paper proposes a new approach for wide angle monitoring of vital signs in smart home applications. The person is tracked using an indoor radar. Upon detecting the person to be static, the radar automatically focuses its beam on that location, and subsequently breathing and heart rates are extracted from the reflected signals using continuous wavelet transform ((Formula presented.)) analysis. In this way, leveraging the radar’s on-chip processor enables real-time monitoring of vital signs across varying angles. In our experiment, we employ a commercial multi-input multi-output (MIMO) millimeter-wave FMCW radar to monitor vital signs within a range of (Formula presented.) to (Formula presented.) m and an angular span of (Formula presented.) to (Formula presented.) deg. In the Bland–Altman plot, the measured results indicate the average difference of (Formula presented.) and (Formula presented.) beats per minute (BPM) relative to the reference for heart rate and breathing rate, respectively.