Millimeter-wave radar vital signs detection based on WSO-VMD algorithm

In this paper, a joint algorithm based on variational mode decomposition (VMD) algorithm and White Shark Optimizer (WSO) algorithm is proposed for non-contact vital signs detection. First, the phase information is obtained from the radar echo signal. Then, the respiratory and heartbeat components are separated using a bandpass filter. The separated respiratory component is processed by second-order differencing. At the same time, the heart rate is estimated by decomposing the separated heartbeat component using WSO-VMD. WSO algorithm makes VMD algorithm parameters adaptive, and filters out breathing harmonics from interfering with the heartbeat. Compared with the bandpass filtering method, the VMD method, and the WOA-VMD method, the mean relative error (MRE) is reduced by 3.61%, 2.99%, and 2.38% respectively. Therefore, the method in this paper can improve the detection accuracy.