Fish heart motion measurements with a body-contact Doppler radar sensor

This paper presents preliminary results demonstrating detection of cardiac motion and monitoring of fish heart rate using a contact antenna as a less-invasive alternative to surgical electrocardiogram (ECG) measurements. Ringtail Surgeonfish were used as initial test subjects with pcb patch and spiral antennas. The frequency of operation, 2.4 GHz, was chosen as a tradeoff between antenna size and propagation. The data show the importance of antenna placement for satisfactory heart motion detection. Measured heart rates varied with time and sedation level, generally near 60 bpm. Of the antennas used, the spiral antenna-provided signal most closely matched that seen with human test subjects.