Popovic D, Gordon T, Rafuse V F, Prochazka A
Division of Neuroscience, University of Alberta, Edmonton, Canada.
Ann Biomed Eng. 1991;19(3):303-16. doi: 10.1007/BF02584305.
Implanted wire electrodes are increasingly being used for the functional electrical stimulation of muscles in partially paralysed patients, yet many of their basic characteristics are poorly understood. In this study we investigated the selectivity, recruitment characteristics and range of control of several types of electrode in triceps surae and plantaris muscles of anaesthetized cats. We found that nerve cuffs are more efficient and selective (i.e., cause less stimulus spread to surrounding muscles) than intramuscular electrodes. Bipolar intramuscular stimulation was more efficient and selective than monopolar stimulation, but only if the nerve entry point was between the electrodes. Monopolar electrodes are efficient and selective if located close to the nerve entry point, but their performance declines with distance from it. Nonetheless, for a variety of reasons monopolar stimulation provides the best compromise in many current applications. Short duration pulses offer the best efficiency (least charge per pulse to elicit force) but high peak currents, increasing the risk of electrode corrosion and tissue damage. Electrode size has little effect on recruitment and should therefore be maximised because this minimises current density.
植入式线电极越来越多地用于对部分瘫痪患者的肌肉进行功能性电刺激，但其许多基本特性仍未得到充分了解。在本研究中，我们调查了麻醉猫的腓肠肌和跖肌中几种类型电极的选择性、募集特性和控制范围。我们发现，神经袖套比肌内电极更有效且更具选择性（即，刺激扩散到周围肌肉的情况更少）。双极肌内刺激比单极刺激更有效且更具选择性，但前提是神经进入点位于电极之间。单极电极如果位于靠近神经进入点的位置则有效且具选择性，但其性能会随着与神经进入点距离的增加而下降。尽管如此，由于多种原因，单极刺激在许多当前应用中提供了最佳折衷方案。短持续时间脉冲具有最佳效率（每脉冲引发力量所需的电荷量最少），但峰值电流较高，增加了电极腐蚀和组织损伤的风险。电极尺寸对募集影响很小，因此应将其最大化，因为这可使电流密度最小化。
