Functional Electrical Stimulation System for Motion Control of Lower and Upper Extremities.

恢复脊髓损伤或脑损伤的截瘫或四肢瘫痪患者的行为功能是其日常生活的巨大社会需求。功能电刺激（FES）是一种重建基本功能的康复技术，因为FES可以激活患者的无神经肌肉。采用开环控制系统和机械支撑系统对截瘫患者的步态功能进行初步恢复。然而，为了获得稳定的双足步态和站立，需要闭环控制系统。本研究采用带闭环控制系统的FES对正常人的关节角度和下肢肌肉收缩力进行闭环控制。整个FES系统由微型计算机、电刺激器、角度和力传感器、模数转换器、数模转换器和电极组成。在研究的第一阶段，明确了下肢FES的生理机制，并在此基础上研制了具有较高电安全性的微机控制刺激器。利用FES系统，分别对踝关节和膝关节的屈伸两个运动方向分别准备了两个PID控制器，实现了关节角度的控制。在控制器中附加命令滤波器，减小了无负载状态下控制角的超调量和波动。在肌力控制方面，采用PID控制器和调节器的FES系统，获得了良好的控制响应。为了研究负载对控制对象的影响，采用模型参考自适应控制系统（MRACS）。在无负载状态下，得到了与设计好的PID控制器相似的控制性能。当载荷变化时，MRACS提供了关节角振荡行为的减少。综上所述，所开发的PID控制器和指令滤波的FES系统以及MRACS系统对于踝关节和膝关节关节角度的控制以及肌肉收缩力的控制都具有很高的实用性。在不久的将来，FES系统可能会用于截瘫患者行为功能的恢复。少

Restoring behavioral functions of paraplegic or quadriplegic patients who have been suffered from spinal cord injury or brain damage is a great social demands for their everday livings. Functional Electrical Stimulation (FES) is one of the rehabilitation techniques to reconstruct the basic functions since the FES can activate the denerved muscles of the patients. Primary restoration of gait functions of the paraplegic patient was attained by using the FES with open-loop control system and mechanical support system. In order to obtain stable biped gait and standing, however,closed-loop control system is required.In this study, closed-loop control of joint angle and muscle contractile force of lower extremety was carried out on normal human subjects by using the FES with closed-loop control system. The total FES system consisted of micro-computer, electrical stimulator, angle and force sensors, AD converter, DA converter, and electrodes. On the first stage of the study, physiological mec … More hanism of the FES on lower extremity was made clear, and then computer controlled stimulator satisfying high electrical safety was developed. Using the FES system, joint angle controls of ankle and knee were carried out with two PID controllers prepared for both moving directions of flexion and extension. Appendant use of command filter in the controllers provided decrease in overshoot and fluctuation of the controlled angle in the load free state. As for the muscle force control, FES system with PID controller and modulator was used and a good control response was obtained. In order to investigated load effect on the control objects, model reference adaptive control system (MRACS) was used. Similar controlled performances to those of the well designed PID controls were obtained in the load free state. When the load changed, MRACS provided decrease in the oscillatory behavior of the joint angle.In conclusion, it can be stated that the developed FES system with PID controller and command filter as well as MRACS are highly available for the joint angle controls of ankle and knee, and also for the control of muscle contractile force. Practical use for restoration of behavioral functions of paraplegic patients might be available using the FES system in the near future. Less