A computer-aided socket design procedure for above-knee prostheses

A computer-aided socket design procedure (CASD) has been developed whereby an above-knee socket shape can be created based on anthropometric measurements taken from an amputee. The anthroometric measurements are used to select a subset of three reference shapes from a Reference Shape Library stored in the computer in the form of three-dimensional numerical data. Transformation procedures then scale the reference shapes at each cross-sectional level to match the amputee's cross-sectional areas. Blending of the three shapes is determined by tissue mass weighting factors, to yield a single custom socket configuration, known as the "basic socket shape." Subsequent graphical procedures in the CASD system allows further sculpting of the shape in the form of interactive adjustments of the numerical data to reach the socket shape desired by the prosthetist. The resultant shape data can then be transferred to a computer numerically controlled (CNC) milling machine to carve a model of the socket shape.