Development of a Low-technology Prosthetic Swing-phase Mechanism

作者：Furse Alex^*; Cleghorn William; Andrysek Jan

来源：Journal of Medical and Biological Engineering, 2011, 31(2): 145-150.

DOI：10.5405/jmbe.821

• Prosthetics
• Above-knee amputee
• Swing-phase control
• Gait
• Biomechanics

Although a number of accessible low-technology prosthetic devices have been developed, most only provide very basic function during the swing-phase. A prosthetic swing-phase control mechanism simulates the action of the upper leg musculature to aid in increased gait function. More specifically, swing-phase control mechanisms limit the maximum knee flexion and allow the shank to smoothly decelerate into full knee extension without excessive impact. In this study, a single above-knee amputee was fitted with a prosthetic knee, and different low-technology swing-phase setups were clinically assessed. Clinical testing included walk tests utilizing a mobile computer setup connected to electrogoniometers (to measure knee flexion angle and time) and accelerometers (to measure terminal impact decelerations) mounted on the sound and prosthetic limbs. As hypothesized, incorporating friction and a spring system improved gait function. The dual spring system, two springs in series, as predicted by our computational model and mechanical testing, out-performed the single spring system. The swing-phase knee torque versus flexion pattern of the dual spring system best matched baseline data from a high-end hydraulic swing-phase controller. Clinical trials revealed increased walking velocity, decreased and more normal maximum prosthetic knee flexion and lower terminal impact with the dual spring systems. The new dual spring mechanism is simple, improves the performance of a prosthesis, and is ideal for use in applications where size, weight and cost may be constraining factors. This includes the provision of prostheses to children and to individuals in developing countries.

• 出版日期2011