Development of an Evaluation System for Magnetic Resonance Imaging Based Three-Dimensional Modeling of a Transfemoral Prosthetic Socket Using Finite Elements

Recent technologies have suggested the utilization of three-dimensional (3D) printingtechnology to enhance the fabrication accuracy of prosthetics. Accordingly, simulations are used toobtain precise parameters for subject-specified prosthetic socket. This study proposes an evaluationsystem to measure the accuracy of a subject-specific 3D transfemoral residuum model duringthe interaction with the socket in conjunction with the application of finite element methods.The proposed system can be used in future validations of socket fabrication. The evaluation isbased on the measurement of the residuum’s soft tissue deformation inside two types of prostheticsockets. In comparison with other studies, the 3D models were constructed with magnetic resonanceimages (MRI) with the aid of computer-aided design (CAD) software. The measurement of soft tissuedeformation was conducted based on the measurement of the volumetric value of fat, muscle andskin in the pre- and post-donning phases. The result yielded a promising correlation coefficient valuebetween the simulation and the experiment in the soft tissue deformation evaluation. The relationof the muscle–fat ratio in the residuum is extremely important in the determination of the abilityof the prosthetic to deform. The environment during the socket fitting session was similar to thatdefined by the set boundary conditions in simulations. In view of the promising results of thisstudy, the evaluation system proposed herein is considered reliable and is envisaged to be used infuture research

A Method to Analyze Dynamics Properties of Transfemoral Prosthesis

Abstract.The methodto compute gait cycle forces and moments acting on the hip and knee joints of a lower limb with a trans-femoral prosthesis were investigated. A 3D model of the lower limb with prosthesis was created using CAD software and based on MRI data and real size dimension. The transfemoral prosthesis was modelled as a coupled of links with two revolution joints at hip and knee joint. This coupled link was connected to a bar with translation joint to description the distance walked of people in gait cycle. All parts of the prosthesis were measured and a full-size 3D model was created.The kinematics parameters of a lower limb with a prosthesis were determined from motion-captured system data. The reaction force was measured with a force sensor in the footplate. The 3D model of the prosthesis was exported to MatlabSimmechanics. The input data which are kinematic parameters were applied to calculate the forces and moments acting on the joints. The results of this study present a method to analyse the dynamic properties of transfemoral prosthesis including speed of the gait. It could be used to calculate the load transferred from the socket to the residual limb. They could also be used to design the structure of a prosthesis and optimize the dynamic characteristics of such a prosthesis

A Method to Analyze Dynamics Properties of Transfemoral Prosthesis

Abstract.The methodto compute gait cycle forces and moments acting on the hip and knee joints of a lower limb with a trans-femoral prosthesis were investigated. A 3D model of the lower limb with prosthesis was created using CAD software and based on MRI data and real size dimension. The transfemoral prosthesis was modelled as a coupled of links with two revolution joints at hip and knee joint. This coupled link was connected to a bar with translation joint to description the distance walked of people in gait cycle. All parts of the prosthesis were measured and a full-size 3D model was created.The kinematics parameters of a lower limb with a prosthesis were determined from motion-captured system data. The reaction force was measured with a force sensor in the footplate. The 3D model of the prosthesis was exported to MatlabSimmechanics. The input data which are kinematic parameters were applied to calculate the forces and moments acting on the joints. The results of this study present a method to analyse the dynamic properties of transfemoral prosthesis including speed of the gait. It could be used to calculate the load transferred from the socket to the residual limb. They could also be used to design the structure of a prosthesis and optimize the dynamic characteristics of such a prosthesis

A Method to Analyze Dynamics Properties of Transfemoral Prosthesis

Abstract.The methodto compute gait cycle forces and moments acting on the hip and knee joints of a lower limb with a trans-femoral prosthesis were investigated. A 3D model of the lower limb with prosthesis was created using CAD software and based on MRI data and real size dimension. The transfemoral prosthesis was modelled as a coupled of links with two revolution joints at hip and knee joint. This coupled link was connected to a bar with translation joint to description the distance walked of people in gait cycle. All parts of the prosthesis were measured and a full-size 3D model was created.The kinematics parameters of a lower limb with a prosthesis were determined from motion-captured system data. The reaction force was measured with a force sensor in the footplate. The 3D model of the prosthesis was exported to MatlabSimmechanics. The input data which are kinematic parameters were applied to calculate the forces and moments acting on the joints. The results of this study present a method to analyse the dynamic properties of transfemoral prosthesis including speed of the gait. It could be used to calculate the load transferred from the socket to the residual limb. They could also be used to design the structure of a prosthesis and optimize the dynamic characteristics of such a prosthesis