Fish Heart Rate Monitoring by Body-Contact Doppler Radar

This paper presents results demonstrating detection of cardiac motion and heart rate monitoring by radar for fish using a contact antenna, as a less-invasive alternative to surgical electrocardiogram (ECG) measurements. Tilapia are used as test subjects with a patch antenna. The frequency of operation, 2.4 GHz, is chosen as a tradeoff between antenna size and propagation. Single lead ECG measurements are used as a reference for comparison with two electrode configurations. The heart rate detected by the radar matched the heart rate detected by ECG. With water temperature near 30
$^{\circ}{\rm C}$
, measured heart rates varied with sedation level and over time, in the range of 30–80 bpm.