Promising research suggests a method for healing difficult wounds
By Larry Kidder
There are people who have to worry about any tiny scratch or cut they receive on a foot. That’s because if an infection develops, they are at risk for losing that foot. A wound that won’t heal can lead to tissue death and potential amputation.
Jerrold S. Petrofsky, PhD, JD, professor of physical therapy and director of the research laboratories in Loma Linda University’s School of Allied Health Professions, is very interested in solving the puzzle of these non-healing wounds.
Diabetics, in particular, are prone to developing wounds that can eventually lead to amputation. The disease process affects the blood flow to the extremities. Reduced blood flow can lead to neuropathy, a condition where the nerve cells in a region die. Loss of sensation makes it easy to receive an injury and not even be aware.
Individuals who spend the majority of time in bed or in a wheelchair may also develop pressure sores, which are also very difficult to heal.
Reduced blood flow to an area has been shown to thwart the healing process. Wounds fester. When wound tissue becomes necrotic—where the tissues literally die—the condition is life-threatening and must be treated immediately. If enough tissue becomes necrotic, a foot may be lost.
Dr. Petrofsky and his research team have been studying the effects of a low electric current passing through a wound. Evidence shows that blood flow is increased when a small electric current passes through tissue.
The research team has looked at different arrays of electrodes, as well as various patterns of electrical currents, to determine which array and pattern deliver the best results.
In the September/October 2008 Journal of Medical Engineering & Technology, Dr. Petrofsky and his team shared their findings. The article, titled “A multi-channel stimulator and electrode array providing a rotating current whirlpool for electrical stimulation of wounds,” describes in a nutshell the team’s methodology.
“When electrical stimulation is used on wounds,” Dr. Petrofsky explains, “the electrical current has difficulty penetrating areas where there is necrotic tissue.”
This is especially true when only two electrodes are employed. “Further,” Dr. Petrofsky continues, “for an irregularly shaped wound, current distribution is poor in some areas of the wound, since conventional two-electrode delivery systems provide the greatest current in the line directly between the electrodes.”
To counter these problems, the research team devised a three-electrode system where each electrode was positive on an alternating basis, with the other two electrodes being negative. This rotating process should more evenly distribute the current across wounds, increasing blood flow to the area and improving the healing process.
To prove their theory, the team tested the stimulator on eight subjects—six normal subjects with no wounds, and two subjects with non-healing wounds. To determine the results, the team measured both the current and the blood flow around the target area.
“The three-electrode system provided even current distribution across a large area of skin,” Dr. Petrofsky reports. The best evidence for this, he adds, was the fact that blood flow increased over the entire area encircled by the three electrodes.
“The system was more predictable in response,” Dr. Petrofsky points out, “irrespective of the size of the area being stimulated.”
Dr. Petrofsky describes the three-electrode system as creating a “whirlpool effect.” This system has been patented by the School of Allied Health Professions.
“The implications for patients with diabetes and other non-healing wounds are immense,” Dr. Petrofsky suggests. “If we can successfully speed up the healing process for these patients, we not only save them pain and suffering, but we reduce the time they spend in the hospital or under other types of costly medical care.”
In the photo, Dr. Petrofsky poses with a paralyzed patient who benefited from research he and his team conducted from 1979-1987 at Wright State University's National Center for Rehabilitation Engineering.