A new advance in health monitoring which uses radar to "listen" to patients' heart sounds with remarkable accuracy could lead to a new generation of contactless medical monitoring equipment. Researchers from the University of Glasgow led the development of the new system, which uses radar to track patients' heart sounds like a doctor uses a stethoscope. It improves significantly on previous methods of measuring heart rate using radar waves, which take readings from measurements of patients' chest movements.

In a new paper published in the journal IEEE Journal of Biomedical and Health Informatics , the team demonstrates how they used advanced signal processing techniques to isolate and measure the heart sounds of human volunteers. Using a 24Ghz continuous-wave radar system, they bounced electromagnetic waves off volunteers' bodies as they lay down, fully-clothed. The reflections of the waves allowed the team to measure not just the movement of their chests but also the sounds their hearts produced as valves opened and closed—a method similar to the way doctors use stethoscopes to hear how patients' hearts are beating.

They used sophisticated filters to remove signal noise and other interference, allowing them to get a clear pulse signal and calculate patients' heart rate. To test the effectiveness of their method, they collected heart sound and chest movement data from male and female volunteers using radar over periods of 30 seconds, 60 seconds, and five minutes. For each t.