A team of researchers from Glasgow University has created a radar system that measures heart rate without patient contact.

According to its makers, the device uses a 24 GHz continuous-wave radar system that bounces electromagnetic waves off fully clothed bodies. The team added that advanced signal processing is then applied to the reflections of the sound waves to offer an accurate pulse reading.

When tested on volunteers, the radar stethoscope matched electrocardiogram (ECG) readings with a 99% rate of accuracy. This suggests that the device could potentially be used to non-invasively monitor patients around the clock.

“What we’ve been able to with this research is take a big step towards enabling the full potential of radar as a contact-free health monitoring tool. Our signal processing approach has enabled much more accurate detection of heart sounds and measurement of heart rate, which bring it close to the performance of ECG monitoring,” the researchers explained.

The team tested the device by collecting heart sound and chest movement data from male and female volunteers using radar over periods of 30 seconds, 60 seconds and five minutes. The team also measured three different intensities of heartbeat — including a ‘resting’ state of between 60 and 80 beats per minute (bpm), an ‘anxiety’ state of 100 bpm to 130 bpm, and a ‘transition’ state of between 80 bpm and 130 bpm. The team reported that readings differed from the simultaneous ECG measurements by less than 1 bpm.

An article detailing the findings, “Contactless Heart Sound detection using Advanced Signal Processing Exploiting Radar Signals,” appears in the journal IEEE Journal of Biomedical and Health Informatics.

To contact the author of this article, email mdonlon@globalspec.com