UHF measurement of breathing and heartbeat at a distance

The detection of breathing and heartbeat from a distance is important for medical triage and mass casualty events as well as routine monitoring of higher-risk patients. Typical approaches include wiring up patients to devices and wearable devices, but remote detection and monitoring is both easier on the patient and easier to administer. Monitoring at low frequencies means that there is less patient risk as well as extended range and reduced power. In this paper we look at the measurement of breathing and heartbeat of human subjects at UHF frequencies. We characterize the system design and capabilities as well as the algorithmic approach to extracting the signal. We measure biometric ground truth using heartbeat sensors, respiration monitors, and accelerometers. We do accurately measure breathing, and can measure heartbeat when the subject is holding his breath, but have not yet separated the heartbeat from breathing when both are being done simultaneously.