Experimental Device Heals Wounds With Low-Frequency Ultrasound

NIH funds five-year study

Researchers at Drexel University in Philadelphia are working on a potential new treatment for the millions of patients with slow-healing chronic wounds. The battery-powered applicator—as small and light as a watch—is the first portable and potentially wearable device to heal wounds with low-frequency ultrasound.

The National Institutes of Health has awarded the research team an estimated $3 million to test the therapy in 120 patients during the next five years. By using diagnostic monitoring of blood flow in the wound tissue, the clinical trial will also determine how nutrition and inflammation affect wound closure, making treatment customization a possibility.

“There is no other existing treatment you can compare it with,” said principal investigator Peter Lewin, PhD. “If we can prove this is effective for a large group of patients, then we have the potential to solve a very costly and debilitating health problem.”

The portable device heals by sending low-frequency (20 kHz) ultrasonic sound waves directly to the chronic wound. While the healing potential of ultrasound to reduce swelling in injuries is well known, high energy levels are not optimal for treating damaged tissue over long periods.

The device Lewin and his colleagues have developed operates at a level of energy much lower than the ultrasound units used to monitor pregnancy. Once the device is fully developed, the applicator may be applied directly to the wound using a thin piece of tegaderm, gel, and medical tape. Then, with the flip of switch, the palm-sized battery pack is turned on, driving the set of transducers inside the device to create acoustic energy and begin the wound-healing process.

Since the device is compact, lightweight, and portable, patients may one day be able to use it in their homes, avoiding the high costs and other inconveniences associated with frequent visits to a doctor’s office.

In 2013, the researchers successfully tested the device in 20 patients at a wound healing clinic. Applying the ultrasound at a frequency of 20 kHz for 15-minute intervals proved to be the most effective combination of energy and duration. All five patients that received this combination of treatment had healed completely by the end of the four-week treatment period. Overall, the study demonstrated that the new treatment improved healing by 15% per week compared with placebo.

If the researchers can substantiate the device’s efficacy and safety during a planned phase 2 trial, in which they will monitor 120 patients during a 16-week period, then they will treat a larger cohort in a third clinical study.

Source: Drexel University; November 29, 2016.