Jia Xiaofeng, Koenig Matthew A, Zhang Xiaowen, Zhang Jian, Chen Tongyi, Chen Zhongwei
Department of Orthopedic Surgery, Zhong Shan Hospital, Fudan University, Shanghai, PR China.
J Hand Surg Am. 2007 May-Jun;32(5):657-66. doi: 10.1016/j.jhsa.2007.02.021.
The residual motor pathways after amputation have not been fully elucidated. We sampled potentials from peripheral nerve stumps with intrafascicular electrodes to study residual motor transmission and explore the feasibility of nerve signal-controlled artificial limbs.
Six intrafascicular electrodes were inserted into the ulnar, radial, and median nerves in the stump of an amputee. An electrode was placed outside the fascicle as a reference. Potentials from 4 of the 6 electrodes per trial were monitored using a 4-channel electromyogram machine, and 32 groups of electrophysiologic tests were conducted under volitional control. Actions included finger extension and flexion, forearm pronation and supination, and wrist extension and flexion. Each action was carried out with light, intermediate, and full efforts. Then, 2 of 6 electrodes randomly chosen per trial were interfaced to a nerve signal-controlled artificial limb. Finger extension and flexion of the prosthesis were tested under volitional control.
The volitional motor nerve potentials uniquely associated with the missing limb were recorded successfully with intrafascicular electrodes. The signal amplitude from the radial nerve was 5.5 microV +/- 0.8 (mean +/- SD), which was greater than the amplitudes from the ulnar (2.5 microV +/- 0.4) and median (2.2 microV +/- 0.3) nerves. Under volitional control of the subject, finger extension of the artificial limb was triggered by the radial nerve signal, but the remaining actions were unsuccessful.
The long-term amputee was able to generate motor neuron activity related to phantom limb movement. Intrafascicular electrodes can be used to monitor residual motor nerve activity in the stump, and the amplitude may predict successful control of artificial limbs.
截肢后残留的运动通路尚未完全阐明。我们使用束内电极从周围神经残端采集电位，以研究残留的运动传导，并探索神经信号控制的假肢的可行性。
将六个束内电极插入一名截肢者残端的尺神经、桡神经和正中神经。在束外放置一个电极作为参考。每次试验使用四通道肌电图仪监测六个电极中四个电极的电位，并在自主控制下进行32组电生理测试。动作包括手指伸展和屈曲、前臂旋前和旋后以及手腕伸展和屈曲。每个动作都以轻度、中度和全力进行。然后，每次试验随机选择六个电极中的两个与神经信号控制的假肢相连。在自主控制下测试假肢的手指伸展和屈曲。
使用束内电极成功记录了与缺失肢体唯一相关的自主运动神经电位。桡神经的信号幅度为5.5微伏±0.8（平均值±标准差），大于尺神经（2.5微伏±0.4）和正中神经（2.2微伏±0.3）的幅度。在受试者的自主控制下，假肢的手指伸展由桡神经信号触发，但其余动作未成功。
长期截肢者能够产生与幻肢运动相关的运动神经元活动。束内电极可用于监测残端残留的运动神经活动，其幅度可能预测假肢控制的成功与否。
