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In this study, we estimated and validated the pressure distribution profile between the residuum and two types of prosthetic sockets for transfemoral amputees by utilizing a finite element analysis. Correct shaping of the socket for an appropriate load distribution is a critical process in the design of lower-limb prosthesis sockets. The pressure distribution profile provides an understanding of the relationship between the socket design and the level of subject comfortability. Estimating the pressure profile is important, as it helps improve the prosthesis through an evaluation of the socket design before it undergoes the fabrication process. This study focused on utilizing a magnetic resonance imaging (MRI)-based three-dimensional (3D) model inside a predetermined finite element simulation. The simulation was predetermined by mimicking the actual socket-fitting environment. The results showed that the potential MRI-based 3D model simulation could be used as an estimation tool for a pressure distribution profile due to the high correlation coefficient value (R 2 > 0.8) calculated when the pressure profiles were compared to the experiment data. The simulation also showed that the pressure distribution in the proximal area was higher (~30%) than in the distal area of the prosthetic socket for every subject. The results of this study will be of tremendous interest for fabricators through the use of a finite element model as an alternative method for the prefabrication and evaluation of prosthetic sockets. In future prosthetic socket fabrications, less intervention will be required in the development of a socket, and the participation of the subject in the socket-fitting session will not be necessary. The results suggest that this study will contribute to expanding the development of an overall prefabrication evaluation system to allow healthcare providers and engineers to simulate the fit and comfort of transfemoral prosthetics.

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Most cases of malformed ears in neonates can be treated by mounting a suitably shaped orthosis. Our objective was to develop a computer-assisted orthosis design and manufacturing system for the treatment of malformed ears. Also, we aimed to manufacture a first experimental orthosis made of nitinol shape-memory alloy wire. First, the target posttherapeutic auricular shape is input from computed tomography scans, and characteristic points and contours are extracted. The shape of the orthosis is then created by tracing the necessary contours automatically. Finally, the orthosis shape data are projected onto one or more approximate planes and autoconverted into numerical control (NC) data for plate groove processing. The nitinol shape-memory alloy wires are inserted in the groove and the shape is memorized by heat treatment. The shape of the manufactured orthosis can be memorized from the generated NC data within 1.0 mm of error. Stahl's ear in a 9-month-old baby was treated 7 months ago by mounting the orthosis manufactured by the system. The developed system allows the design and manufacture of orthoses made of nitinol shape-memory alloy wire for the treatment of malformed ears.

Prosthesis is an artificial part used by amputees as an alternative device to support activities of daily life. It is used to replace the amputated limb and mimic the human movement and locomotion. This paper aims to analyze the stress distribution of a transtibial prosthetic leg during gait cycle using CATIA V5. The dimension of the prototype was based on an average dimension of an actual human foot of Malaysian. The prototype implemented the integration of mechanical and electrical components. Furthermore, the movement of the prototype are based on deviations of angle between pylon and foot. The deviations were detected by rotary angle sensor which then triggered the DC motor to operate. Static analysis had been done using Generative Structural Analysis workbench in CATIA V5 software. Peak von Mises stress were found on the foot at toe off. The highest von Mises stress at the pylon beam was 995MPa and has stress of 156MPa on top of the pylon during heel strike. Furthermore, the foot has peak stress up to 3.18MPa. The result presented here may facilitate improvement of costeffective prosthetic leg. 