Ulcers of diabetes? New shoe sole could heal on the go

WEST LAFAYETTE, Ind. – Diabetes can cause ulcers that patients do not feel or notice before seeing blood. And because ulcers can not cure themselves, 14 to 24 percent of people in the United States who experience it end up losing their toes, foot or leg.

Researchers at Purdue University have developed a shoe sole that could help make the healing process more portable for the 15% of Americans who develop ulcers as a result of diabetes.

"One of the ways to heal these wounds is to give them oxygen," said Babak Ziaie, professor of electrical engineering and computer science at Purdue. "We have created a system that gradually releases oxygen throughout the day so that a patient can have more mobility."

Diabetic ulcers usually result from hyperglycemia caused by nerve damage that removes any sensation of sensation on the toes or feet.

Without the ability to feel pain, blows and bumps tend to go unnoticed and the skin tissue breaks down forming ulcers. A large amount of sugar in the blood, as well as a dry skin resulting from diabetes, further slow down the healing process of the ulcer.

"We usually treat ulcers by removing devitalized tissue from the wound surface and helping the patient find ways to relieve the affected foot," said Desmond Bell, a pediatric specialist in wound management and wound management. prevention of amputation at the Memorial Hospital. in Jacksonville, Florida, and the founder of the Save a Leg Foundation, Save a Life.

"The benchmark for treating an ulcer is that a patient is wearing a full-contact cast, which provides a protective environment for the foot.If we could test how far this insole provides of Oxygen at the wound site from plaster, a means of aiding the healing process, "he said.

Purdue researchers used lasers to shape silicone rubber into insoles and then create oxygen – free reservoirs only on the part of the foot where the ulcer is located. A YouTube video is available at https://youtu.be/DX30YU5rmUM.

The work aligns with the celebration of Purdue's giant steps, recognizing the university's global advances in health, longevity and quality of life as part of Purdue's 150th anniversary. This is one of the four themes of the Festival of Ideas for the year-long celebration and aims to introduce Purdue as an intellectual center solving real-world problems.

"Silicone is flexible and has good permeability to oxygen," said Hongjie Jiang, a postdoctoral researcher in electrical and computer engineering. "Laser machining helps us adjust this permeability and target only the site of the wound, which is hypoxic, rather than poisoning the rest of the foot with too much oxygen."

According to the team's simulations, the insole can provide oxygen at least eight hours a day under the pressure of a person weighing about 53-81 kg (117-179 pounds). But the insoles can be customized to take any weight, say the researchers.

The team plans to send a package of pre-filled and customized soles to a patient based on the site of the wound, based on the "wound profile" obtained from the doctor's prescription and a picture of the foot.

"This is a low-cost mass customization," said Vaibhav Jain, a recent graduate of Purdue's MSc program in Mechanical Engineering and a current research associate in Electrical and Computer Engineering.

Then researchers want to create a way to 3D print the entire insole, rather than print a mold in the first place, then make a laser pattern. They also plan to test the insole on actual diabetic ulcers, to better measure their progress in the healing process.

"We want to bring this technology to the user by addressing the technical issues that may be needed to simplify the manufacturing process," said Jain.

The team published its work in the September issue of Communications from the Materials Research Society, a Cambridge Core journal. Funding for this work was provided by the NextFlex PC 1.0 project.

A patent is pending on the technology of the insole. The team is currently looking for corporate partners.