Wideband Proximity Coupling Sensor for Wrist Heart Rate Monitoring

Accurate and reliable heart rate monitoring is vital for diagnosing various pathologies and ensuring optimal outcomes during surgical procedures. Microwave-based sensors for physiological signal monitoring have gained momentum in recent years. In particular, planar proximity coupling sensors have emerged as a highly desirable option due to their compatibility with wearable devices and surgical technology integration. In this study, we present a microstrip sensor for heart rate monitoring. By taking advantage of its wideband capability, the sensor enables analysis of physiological signals in both the time and frequency domains. The sensor achieves heart rate measurements that are on par with state-of-the-art narrowband sensors, demonstrating its effectiveness in monitoring the heart rate using the phase of the measured forward gain, S
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, within the frequency range from 1 to 6 GHz.