Intelligent signal processing routine for instantaneous heart rate detection using a Six-Port microwave interferometer

Instantaneous heart rate detection is one of the key parameters in medical vital parameter monitoring. In medical centers e.g., real time monitoring of the vital signs of a patient under surveillance is necessary. Nowadays, the dominant technologies are electrocardiogram (ECG) or ballistocardiogram (BCG), but the required direct contact to the person-under-surveillance is a common drawback of these sensors. In this paper, a Six-Port microwave interferometer is presented and used to detect the current heart rate of a person-under-test. An intelligent signal processing routing is proposed that avoids the fast Fourier transform (FFT) due to the implicated longsome observation window and operates directly in the time domain instead. A commercial ECG product is used to proof the reliability of the presented signal processing routine to establish Six-Port microwave interferometers for instantaneous heart rate detection.