Heart Rate Detection Based on Modified-RLMD Algorithm in the Presence of Random Body Movement Using FMCW Radars

The Modified-Robust Local Mean Decomposition (mRLMD) method is introduced as a novel approach for heart rate extraction using a Frequency Modulated Continuous Wave (FMCW) radar system. Based on RLMD, mRLMD utilizes the local median, instead of local mean to minimize the impact of outliers, significantly improving accuracy in challenging conditions. The proposed algorithm is designed to accurately extract heart rate under large-scale random body movement (RBM). By combining an Empirical Mode Decomposition (EMD), a matched filter and differential enhancement, the proposed mRLMD algorithm effectively suppresses RBM and other low-frequency components, such as respiration harmonics, while amplifying the heartbeat signal. Measurement results show that the method achieves an average relative heart rate error of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">${1.98 \%}$</tex>, demonstrating its reliability.