A Low-Frequency Portable Continuous Wave Radar System for Vital Signs Monitoring

Abstract

Modalities for continuous real-time heart rate and respiration rate monitoring is a crucial diagnostic tool, specifically in the early detection of potential health risks and timely intervention to reduce fatality. A low-frequency chest-wearable continuous wave radar device ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RDR–SENSE</i> ) has been designed and developed for continuous monitoring of heart rate and respiration rate. The developed RDR–SENSE device detects the periodic movements in the human thoracic region associated with cardio-pulmonary activities. The chest-wearable low-power RDR–SENSE device has been designed and manufactured in small size (5cm x 5cm). Five volunteers’ cardio-pulmonary activities were collected using the device in five different respiratory scenarios, and a precise signal processing algorithm was applied to derive their heart rate and respiration rate data. The measured data were compared with reference signals to evaluate the RDR–SENSE’s performance. The measured heart and respiration rates were highly promising in terms of accuracy. The mean absolute error was one beat per minute for the heart rate and 0.75 respiration per minute for the respiration rate. The root mean square error was 1.55 BPM for the heart rate and 1.25 RPM for the respiration rate. The developed RDR–SENSE explores the prospects of a chest-wearable, compact, low-frequency radar device for accurate continuous heart rate and respiration rate measurements during seated activities that resemble daily-life study or work.