RESUMO
Objective To design a constant-force extrusion unit to meet the functional requirements of the prosthesis socket. Methods Based on the operational principle that the constant-force derives from offsetting of the positive and negative stiffness, the leaf spring was simulated based on the finite element analysis software. According to the simulation result of the leaf spring, the coefficient of spring stiffness was calculated. The constant-force unit after processing and assembling was tested by compression experiment. Results The simulation result was consistent with experimental result and the constant force of extrusion unit obtained an error about 2% within 3.5-mm range. Conclusions The constant-force characteristic is confirmed by experiment, which lays the foundation of realizing the time-shared and load-bearing hand prosthesis socket.
RESUMO
Objective Aiming at reducing the restrictions on lower limbs imposed by traditional knee brace, a design scheme for knee brace complying with internal-external rotation is proposed. Methods By adding the internal-external hinge, the knee brace could help to release the degree of freedom (DOM) of internal-external rotation of the knee. In the experimental group, the subject was required to wear the bilateral unloading knee brace with or without internal-external hinges, respectively, while in the control group, the subject did not wear the knee brace. Then gait experiment and mechanical testing were conducted. Results In gait experiment, the bilateral unloading knee brace with internal-external hinges imposed less restriction on the knee than that from the knee brace without internal-external hinges, and it could also provide some distractive force for the knee joint. Conclusions The internal-external hinge design can help to reduce restrictions on the knee imposed from bilateral unloading knee brace.