A Purely Mechanical Plantar Pressure Evaluation Device for Diabetic Foot Assessment in Low-Resource Healthcare Settings

Abstract

As global diabetes rates skyrocket, diabetic foot complications constitute a massive and rapidly growing global health problem, causing at least one million lower-extremity amputations every year. These amputations are typically preceded by largely preventable diabetic foot ulcers. However, 80% of the world’s more than half a billion diabetics now live in low- and middle-income countries (LMICs), where many healthcare settings lack the resources to implement recommended diabetic foot assessment and ulcer prevention practices. Evidence from LMICs suggests the need for a novel method of diabetic foot risk evaluation specifically for low-resource contexts. In this study, we present the design of a device that enables a new mode of measuring plantar pressure, a variable established in the medical literature as an accurate predictor of future diabetic foot ulceration. The purely mechanical pressure evaluation device consists of a grid of plastic bistable compliant mechanisms that a subject can step onto and off of with natural gait. Under a relevant pressure threshold, the compliant mechanisms move to a second stable position, an event that can be observed and interpreted by a healthcare provider as indicative of high risk for future ulceration. In settings where standard diabetic foot risk screening is infeasible or insufficient, healthcare providers may evaluate patient foot ulcer risk using the device in a matter of seconds with no need for electricity, computation, or a specialist. Using this simple screening method, strained health systems may be able to allocate scarce healthcare resources more efficiently to prevent costly diabetic foot ulcers and amputations.