Computer-aided design of a prosthetic socket for an above-knee amputee.

A computer-aided design process for fabricating the rectified cast for an above-knee prosthetic socket is described. The methodology for collecting the parameters required for the computer analysis is discussed. The input variables include the unloaded shape of the residual limb, the mechanical properties of the soft tissues that comprise the limb, and the surface loading that deforms the tissue. The technologies that have been developed to ascertain these parameters are presented, and the clinical experience of using the computer-generated shape is presented.

Measuring the shape and volume of an above-knee stump.

A set of design criteria for sensing the shape of an above-knee (AK) stump is presented and used as the basis for evaluating various shape sensing technologies. A mechanical probe type shape sensing system is described and its use in quantifying the external shape of the AK stump is discussed as it relates to generating a grid for finite element analysis in CAD/CAM studies and comparing the segmental volumes of the loaded and unloaded stump. This study also discusses a method that uses circumferential measurements to compute total and incremental volumes of the stump.