Design Of Above-knee Prosthesis Controlled By Emg

Since ancient times, there have been millions of amputee in our society because of the war, diseases, accidents and injuries. With the accelerated development of industry and traffic, the number of amputee is increasing at an astonishing speed. Meanwhile, with the improvement of people's living condition, the requirement of amputee is also increasing. The amputees nowadays do not only pay more attention to the moveable function of prosthesis, but also desire it to be beautiful and replaceable. The prosthesis products of our country is most traditional, weight, and the performance is poor and there is still a big grap with the world's advanced level. Now, it is also an important task to improve the quality of life for amputee and vigorously develop modern prosthesic products. Based on the requirements of amputee, this dissertation designed a six-bar knee prosthesis system controlled with electromyography (EMG).The dissertation was divided into three parts.In section one, the dissertation detailed the transferring ability of instant inactive joints on six-bar mechanism, which can maintain the above-knee (A-K) prosthesis system stable, and the priority of six-bar mechanism on following normal people's gait compared with four-bar mechanism. In one gait period, the six-bar mechanism can enable the mean square error of the ankle less than 1.01% and the mean square error of the knee less than 1.39%. The geometrical relationship of the six-bar mechanism was analyzed. The structure parameter of it was optimized with Complex Penalty Method and computer simulation. The kinematics and dynamics of the mechanism were analyzed. The work principle of mechanism was validated and the interference of it was checked by Pro/ENGINEER.In section two, a method controlled with EMG was put forward, which enabled the subjects to control the A-K prosthesis system freely and voided the embarrass of hand control. Six healthy subjects'quadriceps signals under different conditions (sitting-state, standing-state and walking-state) were analyzed. The research showed that there was a rule when the knee joint rotated. The results above provided necessary fundamental theory for the control of A-K prosthesis system with the EMG At last, the parameters of motor, work principle and timing function of H Bridge, LMD18200 were introduced. Meanwhile a LMD18200 circuit diagram suitable for the project was designed. The character and structure of singlechip AT89C2051 used to control motors were introduced, and the circuit connection diagram of AT89C2051 was designed too.