Research On Biomechanical Assessment And CAE Technology For Lower-limb Prosthetic Socket

The comfort and functional performance of a lower-limb prosthesis are ultimately determined by socket design. However, to date, there was a lack of quantitative assessment technology, and socket modification was still based on prosthetists'personal experiences.Computational simulation based on FEA (Finite Element Analysis) has now become a powerful tool to investigate the stress distribution between the stump and socket, but the model construction is burdensome and can usually be used in basic research only.Accordingly, the research described in this thesis has been carried out to integrate FEA with current CASD/CASM (Computer Aided Socket Design & Manufacture) systems to meet the requirements of biomechanical assessment in clinical prosthetic socket design.3D visualization of stump/socket has been realized based on OpenGL by obtaining geometric information from current CASD/CASM system; according to prosthetists'custom, the information interaction enables user to access information easily and directly on 3D model, and it can also be used to measure modulus or thickness of soft tissues visually in-vivo.A special procedure has been developed to construct FE model of stump/socket. In this procedure, a standard model of tibia and fibula was scaled and positioned according to the thickness of soft tissue at Patellar Tendon and Fibular Head, and then nodes and elements could be generated automatically according to the preference ofuser. Soft tissues modulus in FE models was obtained with in-vivo measurement of the individual, the socket rectification was simulated by applying radial displacements to corresponding nodes.A multimedia database using ADO to access data has been constructed as the platform and interface of the assessment system, it will be very useful in the establishment of design principles.The research described in this thesis played an important role in the first assessment system that can be clinically used in lower-limb socket design. The system can offer designers more quantitative information and make the current CASD/CASM system more effective. It can also be used as an effective tool to perform parametric evaluations. So it will be valuable in both academic research and clinical practice.