Skin patch makes ultrasound images of your heart as you move

A small, flexible patch worn on the chest can create ultrasound images of the heart as people move. The first-of-its-kind device could help diagnose various medical conditions by imaging the heart during exercise.

Doctors currently carry out ultrasound imaging of the heart, called an echocardiogram, by placing a handheld device on the chest that sends and receives ultrasound waves. This is used to visualise the organ after a heart attack, for instance, or in someone who has heart failure, when blood isn’t pumped strongly enough around the body.

According to Hongjie Hu at the University of California, San Diego, doctors currently image someone’s heart before and after they exercise to assess problems that only become apparent when the organ has to work harder. Monitoring heart activity during exercise could aid diagnoses, he says.

Hu and his colleagues therefore made a wearable device for producing and receiving ultrasound waves out of a piezoelectric material, one that can turn electrical energy into mechanical energy and vice versa.

The patch, which is about the size of a postage stamp, converts electrical signals into vibrations to produce the ultrasound waves. It also detects reflected ultrasound waves, which it turns into electrical signals.

The first prototype is connected to a computer that analyses the electrical signals and turns them into images.

When worn by testers, the prototype produced images of the heart that were comparable to a standard handheld device, the team reports.

“There has never been a way to see the heart during exercise before,” says Hu.

A spokesperson for the British Heart Foundation says the device should be able to show the movement and output of the heart, which would be useful for diagnosing conditions such as heart failure and problems with the heart’s valves.

The team has also created a wireless version, the results of which are due to be published in a future paper.