The broad long-term objective of this project is a clinically useful tool for assessing, monitoring, and ultimately predicting skin breakdown from mechanical pressure and shear stress as encountered at the residual limb/prosthetic socket interface during ambulation with a prosthetic limb. ? ? The Specific Aims are to establish relationships between thermal recovery time (TRT) and tissue bioresponse after a controlled mechanical stress is applied, and then to evaluate TRT as a screening test to predict future skin breakdown in amputee subjects. An additional aim is to better understand how biomechanical features of the applied load that can be controlled by a prosthetist through socket design and fitting decision affect TRT and thus tissue response. ? ? To accomplish the aims, first an infrared thermal imaging system is integrated with an existing mechanical loading apparatus to assess TRT after load application. Then well-controlled cyclic pressures and shear stresses are applied to an animal skin model, and quantitative relationships between TRT and physiologic response and between TRT and rapid skin breakdown investigated. The TRT assessment system is then used to monitor amputee subjects in the clinic at monthly intervals to determine if TRT is an effective screening test to predict future skin breakdown. High absolute value TRTs as well as high changes in TRT from one session to the next are expected strong indicators of imminent skin trauma. Then TRT sensitivity to slip vs. stick between the skin and load applicator, a feature that can be controlled by a prosthetist clinically through socket design, is assessed. ? ? The health relatedness of this application is knowledge of importance to the development of an instrument to identify imminent skin breakdown in prosthesis users. Such an instrument could have important clinical impact since collected data could be used to modify prostheses or design treatments to avoid imminent skin breakdown. If effective, potentially this technology could be applied to other areas of rehabilitation, for example, shoe design for patients with insensate feet, cushion design for wheelchair users, and mattress design for bedridden patients ? ?
