Simultaneous multi-person vital signs monitoring using multiple-input multiple-output FMCW millimeter wave radar

Non-contact radar-based vital signs measurement holds immense significance in the context of a rapidly ageing society, underscoring its pivotal role in modern healthcare. While substantial progress has been made in developing radar-based systems for single-person vital sign detection, there remains a conspicuous gap in the domain of simultaneous multi-person measurement. This challenge is compounded by the inherently weak heart signals captured by radar, further exacerbated when dealing with multiple individuals. This paper presents a cutting-edge non-contact measurement system with multiple-input multiple-output (MIMO) frequency modulated continuous wave (FMCW) millimeter wave (mmW) radar for simultaneous multi-person vital signs monitoring. Firstly, a fusion-based approach is presented for multi-person localization within sequential MIMO range-angle maps. Subsequently, an optimization-based method is outlined for the extraction of vital signs, adeptly retrieving respiratory and cardiac signals from the radar’s phase data for each individual. Through extensive experimental validations, the system demonstrates a remarkably low error rate of 1.03% for respiratory measurement and 2.70% for cardiac measurement, reaffirming its efficacy and reliability.