Vital Signs Monitoring Using FMCW Radar for Different Body Orientations in the Presence of Random Body Movement

Abstract

AbstractIn this paper, the discussion is on non-contact vital signs monitoring using a frequency-modulated continuous-wave (FMCW) radar. Here, we analyze the phase of the intermediate frequency (IF) signal in detail. Any human or clutters exposed to the FMCW radar signal can reflect the chirp. The reflected chirp goes to the mixer to produce an IF signal. This paper deals with extracting vital signs such as breathing rate and heart rate from a subject who sits in front of the radar irrespective of the chest orientation toward the radar. The phase of the IF signal is processed to obtain the spectrum in the desired range-bin. The spectrum is further subjected to filtering and thresholding as will be detailed. Random body movements are detected, and those samples are discarded for the calculation of heart rate.KeywordsVital signsBreathe rateHeart rateFFTPhaseUnwrappingChirp