Robinson C J, Flaherty B, Agarwal G C, Gottlieb G L
Rehabilitation R&D Center, Hines VA Hospital, IL.
Biomed Sci Instrum. 1990;26:101-5.
Electrical stimulation of muscle has been proposed as a technique to restore function to paralyzed muscles. But, from a control stand-point, little is known about how such artificial activation interacts with the still intact spinal reflex loops. We have developed instrumentation to measure and compare ankle compliance and muscle EMG activity when the ankle is subjected to perturbations in torque or angular position from bias positions that are achieved volitionally or via electrical muscle stimulation. We deliver precise torque or position perturbations (step, ramp, sinusoidal, random) to the ankle via a pivoting footplate driven by a computer-controlled torque motor. Angular displacement, torque, acceleration, and 2 to 4 channels of electromyographic (EMG) data are collected on analog (VHS) tape and simultaneously digitized and stored. Torque or position biases to normal ankle equilibrium position are applied volitionally (for the neurologically intact) or via electrical stimulation of the Gastroc/Soleus or the Tibialis Anterior muscle (for either the neurologically intact or spinal cord injured). A special stimulator/recording amplifier permits the recording of EMG signals from the muscle being stimulated. An overview of the features and response characteristics of the perturbation system and a comparison from preliminary studies of responses at different biases achieved volitionally versus those achieved by stimulation are presented.
肌肉电刺激已被提议作为一种恢复瘫痪肌肉功能的技术。但是，从控制的角度来看，对于这种人工激活如何与仍然完整的脊髓反射回路相互作用知之甚少。我们已经开发了一种仪器，用于测量和比较当踝关节受到来自通过自主或通过肌肉电刺激实现的偏置位置的扭矩或角位置扰动时的踝关节顺应性和肌肉肌电图（EMG）活动。我们通过由计算机控制的扭矩电机驱动的枢转踏板向踝关节施加精确的扭矩或位置扰动（阶跃、斜坡、正弦、随机）。角位移、扭矩、加速度和2至4通道的肌电图（EMG）数据被采集到模拟（VHS）磁带上，并同时进行数字化和存储。向正常踝关节平衡位置施加扭矩或位置偏置，对于神经功能正常的人通过自主方式进行，对于神经功能正常或脊髓损伤的人则通过对腓肠肌/比目鱼肌或胫骨前肌进行电刺激来实现。一种特殊的刺激器/记录放大器允许记录来自被刺激肌肉的EMG信号。本文介绍了扰动系统的特点和响应特性概述，以及对通过自主方式与通过刺激实现的不同偏置下的响应进行初步研究的比较结果。
