Ultrasound-based tech measures fluid in the lungs

The new approach, demonstrated by a team at North Carolina State University, works by using special algorithms to carefully analyse the echoes of multiple ultrasound waves and thereby build up a picture of the fluid levels in the lungs.

"Historically, it has been difficult to use ultrasound to collect quantitative information on the lung, because ultrasound waves don't travel through air- and the lung is full of air," explained Marie Muller, an assistant professor of mechanical engineering at North Carolina State University and co-author of a paper on the work. "However, we've been able to use the reflective nature of air pockets in the lung to calculate the amount of fluid in the lung."

When ultrasound waves travel through the body, most of each wave's energy passes through the tissue. But some of that energy is reflected as an echo. By monitoring these echoes, an ultrasound scanner is able to create an image of the tissue that the waves passed through. All of this happens in microseconds.