Doppler Vital Signs Detection in the Presence of Large-Scale Random Body Movements

Noncontact detection of human vital signs based on miniaturized Doppler radar systems (DRSs) can be widely used in healthcare and biomedical applications. Although significant progresses have been achieved, a reliable wireless vital signs detection in the presence of large-scale random human body movements remains a technical challenge. In this paper, based on a comprehensive use of the high-dynamic-range radar architecture and linearized Doppler phase demodulation algorithms, we further introduce matched filters to retrieve the respiration and heartbeat spectra completely concealed under the wideband noise floor caused by large-scale body movements. Along with an existing 5.8-GHz system, a single-board integrated DRS operating at 24 GHz was designed to verify the effectiveness of the used architecture and algorithms. Experimental results comply with the theoretical expectation. The obtained results imply the potential to implement practical bioradar systems for human noncontact vital signs detections.