IISc develops self-regulating footwear for diabetics

Bengaluru, June 16, 2022:

 

The Indian Institute of Science (IISc), Department of Mechanical Engineering, in association with the Karnataka Institute of Endocrinology and Research (KIER), has developed a set of self-regulating footwear for diabetic.  

Diabetic foot wounds heal at a slower rate than in healthy individuals, which increases the chance of infection, and may lead to complications that require amputation in extreme cases. 

The footwear developed by the IISc-led team is 3D printed and can be customised to an individual’s foot dimensions and walking style. Unlike conventional therapeutic footwear, a snapping mechanism in these sandals keeps the feet well-balanced, enabling faster healing of the injured region and preventing injuries from arising in other areas of the feet.

The footwear can be especially beneficial for people who have diabetic peripheral neuropathy – those who suffer from nerve damage caused by diabetes, leading to a loss of sensation in the foot. “Diabetic peripheral neuropathy is one of the long-term complications of diabetes, and its diagnosis is mostly neglected. The lack of sensation results in irregular walking patterns in persons with diabetes,” stated Pavan Belehalli, Head, Department of Podiatry, KIER, and one of the authors of the study published in Wearable Technologies.  

For example, a healthy person usually places their heel first on the ground, followed by the foot and toes, and then the heel again. Such a ‘gait cycle’ distributes the pressure evenly across the foot. But due to the loss of sensation, persons with diabetes may not always follow this sequence, which means that the pressure is unevenly distributed. Regions of the foot where the pressure exerted is high are at greater risk of developing ulcers, corns, calluses and other complications, stated the researchers.

There are several varieties of therapeutic footwear in the market. But the researchers observed that it is seen to be ineffective at off-loading the uneven pressure exerted by the ‘abnormal’ gait cycle of persons with diabetes. To address this challenge, they designed arches in their sandals that ‘snap’ to an inverted shape when a pressure beyond a certain threshold is applied. “When we remove the pressure, the arch will automatically come back to its initial position which is known as self-offloading,” stated Priyabrata Maharana, PhD student, Department of Mechanical Engineering, IISc and first author.

“We consider the individual’s weight, foot size, walking speed and pressure distribution to arrive at the maximum force that has to be off-loaded. Multiple arches have been designed along the length of the footwear to off-load the pressure effectively. This is a mechanical solution to a problem. Most of the time, people use electromechanical solutions which involve using sensors and actuators that makes it expensive,” pointed out Prof GK Ananthasuresh, Professor, Department of Mechanical Engineering, IISc, and senior author of the study. 
 
Now the team is collaborating with start-ups Foot Secure and Yostra Labs to commercialise their product. There are many commercial shoe manufacturers selling costly footwear in the name of giving comfort using what they call memory foam, but we have tested them, and they don’t have the required characteristics. This footwear can be used not only by diabetic neuropathy cases, but by others too, said Prof Ananthasuresh.  Pharmabiz