###### Abstract  
Recent technologies have suggested the utilization of three-dimensional (3D) printing technology to enhance the fabrication accuracy of prosthetics. Accordingly, simulations are used to obtain precise parameters for subject-specified prosthetic socket. This study proposes an evaluation system to measure the accuracy of a subject-specific 3D transfemoral residuum model during the 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 is based on the measurement of the residuum's soft tissue deformation inside two types of prosthetic sockets. In comparison with other studies, the 3D models were constructed with magnetic resonance images (MRI) with the aid of computer-aided design (CAD) software. The measurement of soft tissue deformation was conducted based on the measurement of the volumetric value of fat, muscle and skin in the pre- and post-donning phases. The result yielded a promising correlation coefficient value between the simulation and the experiment in the soft tissue deformation evaluation. The relation of the muscle-fat ratio in the residuum is extremely important in the determination of the ability of the prosthetic to deform. The environment during the socket fitting session was similar to that defined by the set boundary conditions in simulations. In view of the promising results of this study, the evaluation system proposed herein is considered reliable and is envisaged to be used in future research. prosthetic socket; finite element method; finite element analysis; transfemoral residuum; biomechanics; bipedal stances; 3D model +
Footnote †: journal: Applied  
compared to the statistic reported five years ago because the number of patients with peripheral vascular disease has increased [1]. Conventional prosthetic device manufacturing has been depended on hand craftsmanship, expertise skills and experience. As a result, current socket design and fitting are inconsistent and vary among prosthetic manufacturers. Furthermore, the process requires considerable time before the end product is obtained and it is really exhausting for the patients who are mostly elderly citizens [2]. Recent developments and applications in biomechanics introduced the utilization of a three-dimensional (3D) printing system to enhance the process of socket design. As reported by [PERSON] [3], 3D printers have been utilized to develop prosthetic devices using antibacterial filaments. The investigation found that the 3D printer is capable of developing effective antibacterial finger prosthesis. Furthermore, the potential of 3D printing in the fabrication of the transfemoral prosthetic socket has also been discussed. According to [PERSON] et al. [4], the design and 3D printing of the transfemoral prosthetic socket required less time compared to conventional methods. However, the evaluation for 3D printing prefabrication has not been discussed in most of the previously published research studies [3; 5; 6; 7]. Finite element analysis (FEA) is extensively used in the evaluation of human anatomy models. For example, in Reference [5], internal strains of transtibial prosthetics have been investigated during load bearing using FEA. Furthermore, investigation of specified prosthetic socket interactions with the transfemoral residuum was also conducted with the same method by measuring the interface pressure on the surface of the residuum [6]. In addition to the prosthetic and orthotic field, FEA was also extensively used in dentistry to develop a future implant. In Reference [7], the development of finite element models from medical images was presented using automated methods. As a result, the proposed methodology revealed its potential to solve linear elasticity problems in two-dimensional (2D) and 3D implementations.