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