Research And Implementation Of Non-Contact Vital Signs Monitoring In Physical Activity Based On Bio-Radars

With high range resolution and strong penetration,bio-radars detect rich information about range,angle,and phase.During the physical activity,effective vital signs monitoring,i.e.breath,heartbeat,and blood pressure,is of great significance for daily healthcare.However,most existing researches request that the targets keep still,which don’t deal with the interference caused by body motions during exercising.And there are few researches about contactless blood pressure monitoring using the bio-radar.This paper aims to research vital signs monitoring in physical activity based on two kinds of bio-radars,including Impulse Radio UltraWideBand(IR-UWB)radar and Frequency Modulated Continuous Wave(FMCW)radar.The breathing and heartbeat are detected during motion,and the feasibility of non-contact blood pressure monitoring is explored,providing a research foundation for vital signs monitoring in full time.During physical activity,the breath and heart rate are estimated without contact based on the IR-UWB radar.In order to deal with the vital signal distortion induced by body motions,a novel joint chest-abdomen cardiopulmonary signal estimation(JCA-CSE)approach is proposed.Breathing and heartbeat are monitored simultaneously by detecting the target’s chest and abdomen movements.The Empirical Wavelet Transform(EWT)is to remove clutter and mitigate movement interference.Moreover,an Improved-Spectrum-Segmentation EWT(ISS-EWT)is applied on each radar to decompose vital signals obtained from chest or abdomen.After that,cross-correlation functions are calculated among chest and abdomen sub-signals to estimate breath and heartbeat.The results of experiments indicate the effectiveness and robustness of the proposed approach,which are published in sensors Journal entitled "Contactless Simultaneous Breathing and Heart Rate Detections in Physical Activity Using IR-UWB Radars".During the rest period after and before exercise,the blood pressure is estimated without contact based on the FMCW radar.Considering the close correlation among the heartbeat,pulse waves,and the blood pressure,a heartbeat-assisted individualized blood pressure estimation(HIBPE)is proposed.With the guidance of heartbeat,the apex signal is extracted,and the pulse wave is recovered with motion interference elimination based on Variational Mode Decomposition(VMD).The signal-beat pulse wave is obtained.Moreover,a blood pressure monitoring network is built.The single-beat pulse wave and individual physiological parameters are applied as network inputs to estimate blood pressure.Experimental results demonstrate the effectiveness and robustness of the proposed algorithm.