Contactless and Short-Range Vital Signs Detection with Doppler Radar Millimeter-Wave (76 - 81 GHz) Sensing Firmware

Vital signs such as heart rate (HR) and respiration rate (RR) are essential physiological parameters used to assess human health and bodily functions. These can be measured via methods that either require or do not require direct contact. A non-contact Doppler radar millimeter (mm)-wave sensing firmware utilizes a 76–81 GHz (W-band) electromagnetic wave over a short-range path to the human body. It then processes the reflected electromagnetic wave to filter and extract human heartbeat and breathing rhythm signals. The short-range sensor system proposed herein eliminates the need for electrodes, electric patches, photoelectric sensors, and conductive wires, as well as the requirement for direct contact with the human body when measuring physiological signals. The W-band Doppler mm-wave sensing firmware, paired with frequency-modulated continuous wave radar, enables continuous monitoring of HR and RR. Short-wavelength mm-waves are employed in short-range detection to deliver highly precise measurements of physiological signals with minimal noise interference. Consequently, experimental tests were conducted in a laboratory setting to measure the heartbeats and breathing rhythm signals of healthy young men. Their HR and RR were estimated through frequency- and time-domain analyses. The experimental results confirm the feasibility of the proposed mm-wave radar for continuous human vital sign detection.