Detection of Vital Signs Based on Variational Mode Decomposition Using FMCW Radar

In this paper, a non-contact method of human vital signs detection is proposed. Frequency modulated continuous wave (FMCW) radar is used, and the variational mode decomposition (VMD) algorithm is applied to the separation of respiratory and heartbeat components in the vital signs. The FMCW radar measures the weak chest surface vibration caused by human respiration and heartbeat movement. After signal windowing and pre-processing, the vital signs of human body at different distances are obtained, and the respiratory and heartbeat components are separated by VMD algorithm. Compared with empirical mode decomposition (EMD), adaptive ensemble empirical mode decomposition (CEEMDAN), the method based on VMD improves the accuracy of the separated instantaneous frequencies of respiratory and heartbeat components, and reduces the fluctuation of real-time vital sign detection results.