Assessment technique for computer-aided manufactured sockets

Abstract

This article presents an assessment technique for testing the quality of prosthetic socket fabrication processes at computer-aided manufacturing facilities. The assessment technique is potentially useful to both facilities making sockets and companies marketing manufacturing equipment seeking to assess and improve product quality. To execute the assessment technique, an evaluator fabricates a collection of test models and sockets using the manufacturing suite under evaluation, then measures their shapes using scanning equipment. Overall socket quality is assessed by comparing socket shapes with electronic file (e-file) shapes. To characterize carving performance, model shapes are compared with e-file shapes. To characterize forming performance, socket shapes are compared with model shapes. The mean radial error (MRE), which is the average difference in radii between the two compared shapes, provides insight into sizing quality. Interquartile range (IQR), the range of radial error for the best-matched half of the points on the compared socket surfaces, provides insight into regional shape quality. The source(s) of socket shape error may be pinpointed by separately determining MRE and IQR for carving and forming. The developed assessment technique may provide a useful tool to the prosthetics community and industry to help identify problems and limitations in computer-aided manufacturing and give insight into appropriate modifications to overcome them.