Human Vital Signs Sensing Based on Millimeter-Wave Radar

Breathing and heartbeat are the most crucial indicators of human vital signs. Compared to contact-based methods for detecting respiration and heartbeat, non-invasive methods, such as radar-based detection, offer a more comfortable and efficient experience. These methods are widely used in fields such as healthcare, disaster rescue, and counter-terrorism. Frequency Modulated Continuous Wave (FMCW) radar combines the ranging capabilities of ultra-wideband radar with the speed measurement capabilities of continuous wave radar. It can distinguish different targets based on distance, thereby reducing clutter interference. This paper conducts a non-contact vital sign detection method through capturing fine-grained chest vibrations caused by breathing and heartbeat. In this study, we utilized a millimeter-wave radar (AWR6843AOP) to extract respiration and heartbeat information with signals reflected from human body. To enhance the waveform, we employed an FIR low-pass filter. The feasibility and accuracy of millimeter-wave radar in detecting human vital signs were verified by comparing the true values obtained from contact measurements with the estimated values derived from radar sensing. A three-transmitter, four-receiver antenna configuration was used to form a 12-channel equivalent array. By using radar imaging to locate the human target, we were able to accurately extract vital sign information. This imaging method allows for the assessment of signal strength from different body parts and the determination of the target's position based on energy.