Optimization of important relief areas in prosthetic socket for below-knee amputees using design of experiment and finite element model

Abstract

Background: In developing countries, there is a need to investigate new methods of a prosthetic socket design for transtibial amputees to provide comfort and satisfaction by using technological advances. Study design: Cases for socket designs were investigated and optimized using finite element model (FEM) and design of experiment (DOE). Objectives: This study focused on the pressure distribution at the limb-socket interface, changes in material properties, socket alignment, and socket rectification; it compares optimized sockets with traditional sockets using three patients. Methods: Finite element modeling and DOE were used for the comparison of pressure distribution and relief areas. The analysis is relevant to loading during stance in a patellar-tendon-bearing transtibial design of socket. Canfit software shows a realistic representation of a refined residual limb where the actual shape was refined then converted to .IGES via SOLIDWORKS 2010 to be properly imported into ANSYS 13. Results: Data collected were used to optimize the final outcome for the prosthetic socket for final fabrication. The socket relieved areas were altered to increase displacement without compromising the socket structural integrity. The prosthetist followed DOE-optimized data during fabrication. Patients were comfortable with the model sockets and irritations were minimized. Conclusion: Results suggest that using the Canfit system with FEM and DOE analysis is an effective method to point out significant local contact pressures, especially at the patellar tendon and fibular head, and improves the functional performance of prosthetic sockets. Clinical relevance: The pressure reliefs at designated areas are seen to be critical in determination of amputees comfort and are very important to clinical applications. This type of analysis may provide better and faster cooperation between rehabilitation centers in developed and underdeveloped countries.