A Wearable Oscillator Tag for Heart Health Monitoring

This paper presents a chest-worn oscillator tag for monitoring the heart health of an exercising person without direct contact with the skin. The tag operates at 5.8 GHz based on the self-injection-locking (SIL) Doppler radar principle and consists mainly of an oscillator and an antenna. For validation, a heart health monitoring system was developed with the proposed tag to detect the cardiac intervals of a wearer who performs various activities including walking and running. The results thus obtained agree closely with electrocardiogram (ECG) measurements.