Through-the-Wall Concurrent Vital Signs Monitoring of Three Subjects Using Single-Channel CW Radar and Independent Component Analysis

This paper reports, for the first time, the capability of a single-channel continuous wave (CW) radar to perform through-the-wall concurrent vital sign monitoring of three subjects using a simpler radar system architecture. Initially, independent component analysis with the joint approximation diagonalization of eigenmatrices (ICA-JADE) was employed to isolate each subject's breathing rate (BR). Subsequently, maximal overlap discrete wavelet transform (MODWT) was implemented as a reinforcement post-processing scheme to denoise and suppress subharmonics in the heart rate (HR) waveforms following the application of ICA-JADE. The results demonstrate an accuracy of approximately 97% in isolating BR using ICA-JADE compared to a traditional chest belt measurement. Furthermore, employing MODWT as a reinforcement post-processing scheme achieved an accuracy of 92% in separating each subject's HR compared to ECG testing. This work has significant potential applications, including post-disaster search and rescue, surveillance, and monitoring vital signs through the wall for healthcare applications.