An in-shoe sensor to help prevent diabetic foot ulcers is being developed in the UK.
Diabetes affects over 4.5 million people in the UK, of whom 2.5 per cent will develop a diabetic foot ulcer (DFU), a debilitating condition that has a huge impact on the patient’s quality of life, and costs the NHS up to £1.13bn annually.
Diabetes affects the nerve and blood supply to peripheral areas of the body, such as the feet, according to Dr Peter Culmer at Leeds University, who is leading the EPSRC-funded project.
“This means your skin is likely to become damaged and ulcerate, but you are also less likely to feel it,” he said. “It can get to the point where an amputation is the only possible solution.”
Over 125 such amputations are carried out in the UK every week, according to Diabetes UK.
To prevent DFUs, and to diagnose and treat those that do occur, clinicians need to understand the behaviour of the sole of the patient’s foot. However, existing in-shoe digital analysis systems are expensive, and measure only a small part of the information needed.
So the research team, which includes specialists from Leeds Teaching Hospitals and the Leeds NIHR Biomedical Research Centre, plans to develop and test an in-shoe sensor capable of measuring pressures on the foot, including normal and sheer forces, and detecting abnormal regions with elevated pressures that are at risk of developing ulcers.
“We want [the device] to be able to monitor the pressures on the soles of people’s feet and identify at-risk patients, and also to collect data that could be used to inform improved footwear for people with the condition,” said Culmer.
The silicon-based tactile sensors will consist of small electronic coils that can be easily printed onto thin flexible films. Each coil will be made up of three layers: a bottom coil layer, a thin, “squashable” middle layer, and a top contact layer.
An array of the sensors will be placed across the film, creating a sensing “sole” capable of taking measurements at various key regions of the foot. This will be combined with a mobile data logging system, to collect the information gathered by the sensors.