Diabetic mellitus patients have foot problems such as loss of sensation, insufficient blood flow to lower extremities and alterations in shape of their pressure patterns causing concentrated high pressure regions. These peaks are due to the disfunctional feed back system from their mechanoreceptors and may lead to complex problems such as amputation if not identified and treated in timely manner. Our main objective is to protect the foot by sensing the abnormal peaks and redistribute the pressure from excessive pressure regions. Therefore, we are developing a design layout for an adaptable shoe insert useful for diabetic foot care. In this paper, the design of adaptive footwear using multi airbag measurement system is presented as a part of our design phase I. The human foot anatomy and anthropometry is studied and insole footwear is designed to auto sense the pressure distribution of the diabetic foot. The biomechanical foot design using a spring-mass-damper mathematical model is used to analyze the mechanical energy distribution and the patterns of stress and strain affecting the foot. The proposed multi airbag shoe insert has a sensing grid that measures the actual pressure of the diabetic patient. The optimal pressure distribution pattern is calculated using foot and insert models and the contact foot pressures are adjusted accordingly reducing the error between the normal and abnormal distribution. The pressure control unit adjusts the airbag shoe insert controlled by the dynamical system. The proposed adaptive multi airbag shoe insert design prototype can be very useful for diabetic foot care.
Available at: http://works.bepress.com/uwe_reischl/14/