Vital Sign Detection Using Millimeter-Wave Radar Based on Two-Channel VMD with Channel Selection

Millimeter wave radar has been widely used in the field of health care because of its obvious advantages in noncontact vital signs detection technology. In this paper a two-channel variational mode decomposition (VMD) method based on channel selection is proposed. Specifically, a comprehensive index is constructed by combining signal-to-noise ratio and time-domain energy characteristics, and the two channels with the highest index value are selected to extract the characteristics of vital signs. For VMD operation, the number of decomposition layers is set to three to better extract the vital signs component from the filtered signal of vital signs. For the intrinsic mode function processed by two-channel VMD, the Pearson correlation coefficient is used to calculate the linear correlation between each modal component of each channel, and the IMF pair with the highest correlation is selected to determine the final estimation result. Experimental results show that compared with the existing time-frequency domain estimation(TFDE), two channel correlation(TCC), and single channel VMD methods(SCVMD), this method improves the detection accuracy and stability of vital signs.