A laser plantar pressure sensor for the diabetic foot

This paper describes the design and development of a high-resolution pressure sensor for use in the field of foot pressure measurement. The device uses an interferometry technique that involves the use of a laser light directed onto a pressure sensitive plate. The pressure plate compresses when a load is applied, and it is this compression which is measured by the interferometry technique. The interference pattern (interferogram) produced represents the pressure distribution across the plate. The interferogram is inputted into the computer using a high pixel CCD camera and video capture card. A fringe analysis program then converts the interferogram into a three-dimensional image of the pressure distribution. A prototype system is described and the initial results show that the system can produce a high resolution image with dynamic capabilities.