Researchers at Drexel University in Philadelphia found that the application of low-intensity ultrasound directly to a wound significantly accelerated the healing process, according to a study published in the Journal of the Acoustical Society of America.

The researchers treated patients with 15 minutes of 20 kilohertz (kHz) ultrasound, 45 minutes of 20 kHz ultrasound, 15 minutes of 100 kHz ultrasound or 15 minutes of a placebo ultrasound. They found that the patients receiving 15 minutes of 20 kHz ultrasound showed the greatest improvement, with all five patients in that group experiencing complete healing by the fourth treatment. They also found that the patients who received low-frequency ultrasound treatment in addition to compression therapy during their weekly check-up showed a net reduction in wound size after 4 weeks, whereas patients who did not receive ultrasound therapy experienced an average increase in wound size during the same period.

The study authors also designed and created a lightweight, battery-operated ultrasound patch that can be worn directly on the wound site like a bandage. This allows for use of the device in a home environment and prevents unnecessary doctor’s visits.

“Most ultrasound transducers require a large apparatus and need to be plugged into the wall. We wanted this to be fully wearable as well as portable, so we needed to make it battery-powered. To achieve that, we had had to design a transducer that could produce medically relevant energy levels using minimum voltage,” Peter A. Lewin, PhD, lead researcher and Richard B. Beard professor of biomedical engineering at Drexel, stated in a news release.