Posted on January 11th, 2023.

An innovative new insole has been pioneered that may help diabetics with foot ulcers heal more quickly, by supplying more oxygen to them. 

The invention has been developed at Purdue University in Indiana, US, with the insoles being made from silicone-based rubber.

A key feature is the installation of reservoirs of oxygen that release the gas to the very point where the ulcer is located, due to each insole being tailor-made.

They are designed to release oxygen for a minimum of eight hours a day for someone who weighs between 53 and 81 kg, although it can be customised according to the weight of the patient. 

Oxygen is released at a rate of 1.8 mmHg/min/cm2, and crucially, the insole will still work when the wearer is sitting down. 

Initially, the insoles have been printed as a mould and then have had patterns laser-machined into them to create the oxygen reservoirs. However, the design team hopes to be able to 3D print them going forward.

The sole will now need to be tested on wearers who have foot ulcers to establish how much it helps the healing process. A patent is also pending on the technology and the team is seeking corporate partners to help fund the widespread production of the insoles if they are shown to be a success. 

Podiatrist Desmond Bell, who works in the field of wound management and amputation prevention at the Memorial Hospital in Jacksonville, Florida, said normal treatment involves removing damaged tissue from the wound and keeping the pressure off it. 

He added: "The gold standard for treating an ulcer is a patient wearing a total-contact cast, which provides a protective environment for the foot. 

"If we could test how well this insole delivers oxygen to the wound site from within the cast, then this could be a way of aiding the healing process."

Original article. Mediplacements.