An ultrasonic debriding device is used to help get rid of dead tissue in a wound and promote healing. Ordinary saline is run through it, heated, and then applied to the skin.

Dr. James Gleaves of Rush Hospital's Wound Care and Hyperbaric Center explained how it works.

"Basically just hold it next to the wound and the ultrasonic wave is carried by the saline into the wound and it'll actually debride the wound," said Gleave. "It leaves a fog and and looks an awful lot like a plant mister."

What the patient feels is warm or hot on the skin, depending on how fast the device is moved. Gleaves said the energy produced bounces off the skin and separates good tissue from the bad. It's less painful than a scalpel, and more efficient. A scalpel takes off both bad and good tissue.

"Once you get rid of the necrotic tissue in a wound, the wound will heal better. Necrotic tissue carries bacteria and other substances that basically delay wound healing. It also kills bacteria in the wound itself," said Gleaves. "Even once you get rid of the necrotic tissue it'll actually kill bacteria down through a depth of a centimeter or so. This particular tip is designed, particularly in diabetic feet and things that are numb, you can actually use this to cut tissue."

The procedure usually takes only 5 to 10 minutes for each wound.