Engineers at the University of California San Diego developed a soft and stretchy ultrasound patch that can be worn on the skin to monitor blood flow through major arteries and veins deep inside a person's body.

Knowing how fast and how much blood flows through a patient's blood vessels is important because it can help clinicians diagnose various cardiovascular conditions, including blood clots; heart valve problems; poor circulation in the limbs; or blockages in the arteries that could lead to strokes or heart attacks.

This soft, stretchy skin patch uses ultrasound to monitor blood flow to organs like the heart and brain. This image was selected as the cover image for the July 2021 issue of Nature Biomedical Engineering.

The new ultrasound patch developed at UC San Diego can continuously monitor blood flow—as well as blood pressure and heart function—in real time. Wearing such a device could make it easier to identify cardiovascular problems early on.

A team led by Sheng Xu, a professor of nanoengineering at the UC San Diego Jacobs School of Engineering, reported the patch in a paper published July 16 in Nature Biomedical Engineering.

The patch can be worn on the neck or chest. What's special about the patch is that it can sense and measure cardiovascular signals as deep as 14 centimeters inside the body in a non-invasive manner. And it can do so with high accuracy.

"This type of wearable device can give you a more comprehensive, more accurate picture of what's going on in deep tissues and critical organs like the heart and the brain, all from the surface of the skin," said Xu.