Novel Heartbeat Detection Method in Presence of Large-Scale Random Body Movement Using SFCW Radar: A Simulated Study

This paper introduces a novel signal processing method for wideband radar system to estimate heart rate in presence of large random body movement. The new method estimates the bulk body motion prior to range transformation by dividing the wideband signal into multiple narrowband continuous waves. Each subband is used to obtain a coarse estimate then combined to produce a refined estimate. The heart rate is indirectly estimated from radar heart sound signal by looking at the heart sound repetition frequency. Since the heart sound signal is mainly located at much higher frequencies than the fundamental heartbeat frequency, the final body motion estimate is low-passed version of the refined estimate to preserve the high frequency heart sound. The motion cancellation occurs at complex signal domain after locating the targeted range bins of interest without the need of judicious phase calibration. The proposed theory is validated using a simulated K-band stepped-frequency continuous wave radar system. Monte carlo simulation study shows that the developed signal processing technique and heart sound recovery based heart rate estimation almost achieve perfect accuracy in presence of large-scale body motion.