Foot ulceration is a diabetic complication estimated to result in over $1 billion worth of medical expenses per year in the United States alone. This multifaceted problem involves the response of plantar soft tissue to both external forces applied to the epidermis and internal changes such as vascular supply and neuropathy. Increasing evidence indicates that a combination of elevated external forces (pressure and shear) and altered tissue properties is of prime importance in the etiology of foot ulcers. The overall goal of this research is to develop a software package that will allow a clinician to see an accurate representation of three-dimensional (3-D) pressure and shear patterns on the plantar surface and identify areas of concern. Adaptable to a variety of measurement systems, the software uses innovative techniques to simultaneously visualize horizontal shear and vertical pressure. User options are available to enhance the visualization. Phase I results demonstrated that the visualization approach and prototype software can provide clear indication of both shear and pressure and the relationship between the two. Analysis algorithms have been created that identify location and magnitude of patterns of pressure and stress most likely to cause, pathological consequences to the skin. Orthopedic specialists have evaluated the software using baseline data from an experimental sensor array and simulated data in the same format and provided positive feedback regarding its utility. Based on these achievements, the Phase II work will focus on development of a complete software system for foot pressure and shear data visualization and analysis. Tasks include design of a flexible data model, an extensive suite of automated analysis tools, a comprehensive, easy-to use graphical user interface, and implementation of these features in a modular software architecture suitable for commercialization as either a turnkey system or a module for integration in a sensor vendor's existing software. Other Phase II activities include the establishment of licensing arrangements with one or more hardware vendors to use the software in conjunction with their systems. In conjunction with a new generation of measurement systems that monitor vertical pressure and horizontal shear forces, this software will emerge as a key tool for research in the etiology of foot ulcers and clinical evaluation of risk factors in diabetic patients.
