OBJECTIVE:To overcome the shortcoming of manual method,computer-aided manufacturing (CAM) system of prosthetic socket is applied to improve socket's quality and processing efficiency,which also reduces the demand of operator's knowledge and experience.METHODS:Prosthetic socket CAM system was discussed based on an advanced manufacture technology,and the hardware and software were designed.The advanced manufacture platform was composed of an industrial personal computer (IPC),a motion control card,four sets of Panasonic digital AC servo control system,four lead screw guides,two spindle motor of milling cutter,a transducer,two switching power supply,limit switch and proximity switch.The software of prosthetic socket CAM system mainly included three function modules:parameter setting,machine testing and beginning processing.Through adjusting command pulse's input and driver's coefficient,the motor worked at different speeds.RESULTS:The result of experiment demonstrated that maximum rotational speed restriction was applied to protect the motor,and the motor could work very smoothly without vibration in very low speed.It was suitable for manufacture prosthetic sockets,and could manufacture the high quality prosthetic socket to satisfy the requirements of amputee.CONCLUSION:Prosthetic socket CAM system based on the advanced manufacture platform can overcome the shortcoming of traditional manual method,ensure product quality,and reduce the cost.The protracted experience of certified prosthetist was incorporated into the design program to reduce the demand of manipulator's knowledge and experience,increase the one-time success rate of manufacture prosthetic sockets,and improve the quality uncertainty of sockets.It can change the backward production mode of designing,measuring,taking model,and modifying model which depends on handwork.

Objective To establish a finite element model of the hallux valgus foot and study the stress and displacement changes in the first and second rays of the hallux valgus under different tensile forces.Methods Foot CT images of a patient with hallux valgus were imported into Mimics to reconstruct a three-dimensional(3D)skeletal model of the foot.The 3-matic software was used to mesh the reconstructed model and generate the volume mesh.The optimized model was imported into ANSYS for finite element analysis.The relationship between the tensile forces and the stress/displacement of the first and second rays of the hallux valgus was verified by changing the size and direction of the tensile forces.Results Tensile forces of different magnitudes and directions were applied to the first proximal phalanx.When the force was less than 12 N,with an increase in tension,the displacement of the first phalange changed more significantly.For every 2 N increase in tension,the displacement increased by approximately 1 mm.When the force was greater than 12 N,with an increase in tension,the stress on the first phalange increased,whereas the displacement only changed slightly.In addition,when the magnitude of the force remained unchanged at 12 N and the direction of the force changed at intervals of 15°,the stress and stress distributions of the first and second rays changed with direction,and the displacement also changed accordingly.When the direction of the force was perpendicular to that of the second phalanx,the displacement of the first phalanx increased.Conclusions Finite element analysis technology can vividly and accurately analyze the stress and displacement changes of the first and second rays of hallux valgus under different tensile forces,and it lays a foundation for the design of hallux valgus orthoses.