The Development and Strength Reinforcement of Rapid Prototyping Prosthetic Socket Coated with a Resin Layer for Transtibial Amputee

摘要

This article proposed a computer-aided engineering process that is to fabricate a prosthetic socket using rapid prototyping technology. Moreover, since current RP machines use a layer-based process to manufacture products, this result in RP products liable to break along layers once bending moment is applied. To prevent RP prosthetic socket from breaking, this study proposes wrapping a layer of unsaturated polyester resin (UPR) around the prosthetic socket to reinforce its strength. Factors affecting the strength of the resin-reinforced RP socket include thickness and forming orientation of the preliminary RP socket, thickness of the UPR layer, and type of material used to make the preliminary RP socket. This study employed Taguchi experimental design method to design a series of test specimens for use by the 3-point bending test. Based on analysis of the results of the bending strength test, the design parameters for a resin-reinforced transtibial socket of appropriate strength can be determined. The preliminary RP socket for a specific transtibial amputee is fabricated using an FDM machine and then wrapped with a reinforcing layer of UPR. To confirm the applicability of the resin-reinforced socket developed in this study, the measurement of interface pressures between the residual limb and the socket was implemented. Analysis of the result of this measurement would assist a prosthetist to realize the distribution of interface pressures at the pressure-tolerant (PT) and pressure-relief (PR) areas of the residual limb while the resin-reinforced RP socket is being worn. The result of this study demonstrates that by integrating a CAD system, reverse engineering and RP technologies, a qualified resin-reinforced RP socket can be fabricated that meets the requirements of a transtibial amputee. The quality uncertainty of sockets can be improved if the proposed socket and the corresponding production procedure are adopted to replace the traditional manual method of fabrication.