‘MAGIC’ INSOLE WARNS OF FOOT ULCER RISK
HiGH-tecH shoe insoles worn daily could detect foot ulcers weeks before they start to show. the hope is that the insoles could help to reduce the number of diabetes-related amputations made necessary by foot ulcers that will not heal — around 6,000 people a year in england alone have leg, foot or toe amputations due to diabetes complications. the new, high-tech insoles, which are just a few millimetres thick, contain eight tiny sensors to measure pressure on different areas of the soles of the feet.
When there is too much pressure — for example, from walking too far or standing in one position for too long — the blood supply is reduced, starving the tissue of oxygen and increasing the chance of a tiny cut developing into an ulcer (an open sore).
the sensors detect this excess pressure and transmit a warning, via a gadget that clips to the top of the shoe, to a special ‘smart’ watch worn by the patient. this shows which foot is affected and the location of the problem. the patient can then act to prevent an ulcer forming — shifting weight to another part of the foot, walking around to spread the load, or sitting down for five to ten minutes to allow blood to flow back into the high-risk area.
More than four million people in the UK have type 1 or type 2 diabetes. At least one in ten — around 400,000 people — develops poor circulation to the legs and feet because high sugar levels in the blood thicken the walls of capillaries (tiny blood vessels) in the lower leg, making them less efficient at delivering blood. this, in turn, makes the healing process slower and less efficient.
the risks are heightened as those with type 1 or type 2 diabetes often have nerve damage in the feet, so feel little pain and don’t know they have tiny injuries until they become infected and harder to heal.
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with type 1 diabetes are at greatest risk, but ulcers can also affect the two million people with peripheral arterial disease, where arteries in the lower legs become narrowed due to fatty deposits.
Up to 40 per cent of diabetic ulcers take at least three months to heal and, in around 14 per cent of cases, the wounds persist after a year despite treatment, which involves antibiotics and a plaster cast to take pressure off the ulcer.
A recent trial by Manchester Metropolitan University, the University of Manchester and the Manchester Diabetes centre tested the insoles on 90 diabetes patients who had already suffered a foot ulcer that had healed, but were at high risk of developing another.
All volunteers wore the insoles every day, but in half the system was disabled so they received no alerts.
the results, reported in the latest edition of the Lancet Digital Health, showed those given regular smartwatch warnings were 71 per cent less likely to suffer another foot ulcer during the 18-month experiment.
Dr caroline Abbott, a research fellow at Manchester Metropolitan University, who led the study, said: ‘smart insoles could become available on prescription for highrisk diabetics in the UK.’
But David Matthews, a professor of diabetes medicine at oxford University, said that larger studies were needed before the insoles could be used on the NHs.