Kantor G, Alon G, Ho H S
Electrophysics Branch (HFZ 133), Food and Drug Administration, Rockville, MD 20857.
Phys Ther. 1994 Oct;74(10):951-62. doi: 10.1093/ptj/74.10.951.
The purposes of this investigation were to determine the effect of five commonly used voltage waveforms (four pulsed and one sinusoidal) on excitation of sensory and motor nerves and to characterize variables associated with reaching threshold.
Eighteen healthy subjects were stimulated during one session via surface electrodes placed over the forearm and leg.
Stimulation amplitude was increased at a constant rate, and the threshold of sensory and motor excitation was determined. Measured variables included peak voltage, peak current, phase charge, and total pulse charge.
Three-factorial, repeated-measures analysis of variance and Newman-Keuls tests revealed that phase charge varied the least during excitation induced by the five waveforms. Total pulse charge markedly increased when bursts of 10 symmetrical pulses, 25 symmetrical pulses, or amplitude-modulated waveforms were used. Monophasic and symmetrical biphasic waveforms required the least amount of total pulse charge. All measurements were higher during motor threshold than during sensory threshold, and the measurements were higher in the leg than in the forearm.
The authors concluded that all five studied waveforms were effective at threshold excitation of peripheral sensory and motor nerves. Of the five waveforms, the symmetrical biphasic waveform, having a low total pulse charge, may be the preferred waveform, and the 25 symmetrical pulses and amplitude-modulated waveforms may be considered the least preferred due to high total pulse charge.
本研究旨在确定五种常用电压波形（四种脉冲波形和一种正弦波形）对感觉神经和运动神经兴奋的影响，并确定与达到阈值相关的变量。
在一次实验中，通过放置在前臂和腿部的表面电极对18名健康受试者进行刺激。
以恒定速率增加刺激幅度，确定感觉和运动兴奋的阈值。测量的变量包括峰值电压、峰值电流、相电荷和总脉冲电荷。
三因素重复测量方差分析和纽曼-基尔斯检验显示，在五种波形诱发的兴奋过程中，相电荷变化最小。当使用10个对称脉冲、25个对称脉冲或调幅波形的脉冲串时，总脉冲电荷显著增加。单相和对称双相波形所需的总脉冲电荷量最少。运动阈值时的所有测量值均高于感觉阈值时的测量值，且腿部的测量值高于前臂。
作者得出结论，所有五种研究波形在外周感觉神经和运动神经的阈值兴奋方面均有效。在这五种波形中，总脉冲电荷较低的对称双相波形可能是首选波形，而25个对称脉冲和调幅波形由于总脉冲电荷较高，可能被认为是最不理想的波形。
