Low Cost IR-UWB Radar for Multisubject Non-Contact Vital Sign Detection

Impulse Radar Ultra-Wideband (IR-UWB) radar has a high range resolution due to its available wide band; thus, it can precisely localize more than one target along its range. However, it has been criticized for its inefficiency in terms of complexity and cost when used for vital sign detection. Here, we utilize a low-cost novel IR radar chip for non-contact vital-sign sensing that could be used for either single or multiple subjects' vital sign detection. The approach uses a commercial low cost 8 GHz IR-UWB Doppler radar chip with a combination of arctangent demodulation (AD) and Short-Time State-Space Method (ST-SSM) algorithms to successfully and accurately extract the phase variation signals to estimate the respiration rate and heart rate of a subject. Precise range information of the scene is utilized to clearly discern multiple targets, making it possible to detect vital signs multiple targets within the few cm range resolution. The proposed method can accurately operate in real time and it is feasible to be used for patients' health tracking, elderly care, emergency surveillance, and infant sleep apnea monitoring as well.