According to the American Podiatric Medical Association, approximately 15 percent of diabetics will develop chronic foot ulcers. A large percentage of those people will in turn require amputations. Help could be on the way, though … in the form of a rubber insole.

Developed at Indiana's Purdue University, the prototype two-layered insole is made of polydimethylsiloxane, which is a type of silicone. Its bottom layer is actually a chamber that contains oxygen gas, while the top layer is laser-ablated to be particularly oxygen-permeable right at the point where the ulcer is located.

The idea is that as the wearer walks throughout the day, placing pressure upon the insole, oxygen is continuously forced out of the bottom layer, up through the top layer and into the oxygen-deprived tissue of the ulcer – there, it helps accelerate healing. Even when they're sitting, the patient's foot will still exert enough pressure to deliver some oxygen to the wound.

Based on simulations, it is estimated that the present prototype could provide oxygen under the pressure of a person weighing 53 to 81 kg (117 to 179 lb) for at least eight hours. That said, the permeability of the insoles could be tweaked to accommodate patients of different weights.

And while the prototype was created from a mould via a laser-machining process, it is hoped that packs of the insoles could ultimately be 3D-printed for individual patients based on photos of the soles of their feet (see image above). Those patients could then stay mobile and go about their daily duties, while also treating their ulcers. By contrast, traditional hyperbaric oxygen therapy requires them to remain immobile for extended periods of time.

The team is now looking for corporate partners to help commercialize the patent-pending technology. Clinical trials on diabetic patients are also in the works.

A paper on the research was recently published in the journal Materials Research Society Communications.

View gallery - 2 images