A Novel Non-Contact Respiration and Heartbeat Detection Method Using Frequency-Modulated Continuous Wave Radar

Since respiration and heartbeat are important vital signs of humans, it is meaningful to measure them throughout the day with comfortable experience. This article proposes the use of the frequency-modulated continuous wave (FMCW) radar for non-contact and non-invasive vital signs measurement (VSM). Specifically, the fast Fourier transform (FFT) is applied to the intermediate frequency (IF) signal of the radar to obtain the human chest position, and the phase information on the measured position is collected. Then, the extracted phase is processed by the extended differential and cross-multiply algorithm. The eigenvalues selection based on singular spectrum analysis (SSA) method is proposed to suppress the interference and noise. Finally, a novel VItal SIigns signals recONstruction (VISION) scheme is further proposed to extract the intrinsic mode functions (IMFs) components and reconstruct the respiratory and heartbeat signals effectively. The test platform is built and the experiments are carried out to validate the feasibility and effectiveness of the proposed method, and the measured results are very close to those achieved by contact sensors.