Simultaneous Monitoring of Multiple People’s Vital Sign Leveraging a Single Phased-MIMO Radar

Vital sign monitoring plays a critical role in tracking the physiological state of people and enabling various health-related applications (e.g., recommending change lifestyle, examining risk diseases). Traditional approaches rely on hospitalization or body-attached instruments, which are costly intrusive. However, recent years there is an emergence contact-less vital techniques that radio frequency signals. Early studies with continuous wave radars/WiFi devices have shown good success detecting signs single individual, while simultaneous multiple, closely spaced subjects remains challenge. In this paper, using off-the-shelf Texas Instrument automotive FMCW radar, we design implement time-division multiplexing (TDM) phased-MIMO radar sensing system allows high-precision multiple subjects. The proposed can steer beam towards desired directions micro-second delay. steerable enables capturing individuals at same radial distance to radar. formation virtual array aperture longer than physical array. A Capon beamformer used receiver side combine data collected from different transmit receive antenna pairs corresponding As all those provide independent information about targets, their combination significantly boosts signal-to-noise ratio. Based designed TDM develop automatically localize human estimate signs. Extensive evaluations show under two-subject scenarios, our achieve more 98.06% accuracy for breathing rate (BR) 82.89% heartbeat (HR) estimation, subject-to-radar $\text{1.6}\;m$ when targets facing minimal subject-to-subject angle separation notation="LaTeX">$30^\circ $ , close notation="LaTeX">$\text{0.3}\;m$ between two subjects, outperforms state-of-the-art.