Foot to Shoe Friction Energy Proxy During Gait

Diabetic foot lesions are seen when excess friction develops between foot and shoe. The objective is to select appropriate sensors for frictional energy estimation to be included in a wearable device inside the shoe for diabetic foot lesion prevention. Foot to shoe frictional energy dissipation is estimated here as the product of displacement by shear force, which can be obtained as the vertical force or weight of the person multiplied by a coefficient of friction. We compared fifteen sensors’ characteristics: sensitivity, linearity, and accuracy. To evaluate the displacement, we used a giant magnetoresistance sensor. To simulate frictional energy, we used the magnetic field B as the magneto-resistive sensor voltage output with a Neodymium cylindric magnet N45 (3 mm × 1 mm). The NVE ALT023 was selected due to its sensibility 200 mV/v/mT, size (2.5 mm × 2.5 mm) and linearity kept in the range zero to 20 mm of displacement. The sensor is promising candidate for frictional energy measurement during gait, offering potential advancements in diabetic foot monitoring technology as a noninvasive element between the diabetic foot and hosiery.