A small, liquid-filled sensor can continuously and accurately measure heart and lung sounds, detecting cardiac problems or shortness of breath at an early stage, something which could warn heart failure patients of health deterioration and also help pick up early signs of infections such as Covid-19.
Many of us own smart watches or fitness trackers, a large number of which now include heart rate monitors. However, while their accuracy has improved, they offer fairly limited information about heart health. They mostly measure heart rate by shining a green light through the skin, a method called photoplethysmography, which controversially works much better on lighter rather than darker skin.
Heart sounds, such as those heard by a stethoscope, can give a more accurate picture of heart health as they can pick up inconsistencies of rhythm as well as rate. But have been historically harder to track using a wearable device.
To try and get round this problem, Yong Xu, a professor of…