利用单电极不对称双向脉冲电刺激实现有髓神经传导阻断的仿真研究

Simulation analysis of myelinated axon block using asymmetric biphasic electrical current with a monopolar point electrode

基于McNeal的神经电缆模型,以有限长度的有髓神经纤维F-H模型为研究对象,探讨采用单电极不对称双向脉冲刺激实现有髓神经传导阻断的规律。仿真结果表明,当刺激脉冲的频率高于9kHz时,不对称双向脉冲可实现不同直径(2～20μm)神经纤维的完全阻断,并且阻断电流的强度随刺激频率的升高而增大。粗纤维具有更低的阻断阈值。刺激电极-神经纤维距离增大时,神经纤维实现完全阻断所需电流强度随之增大。仿真温度从20℃升高到37℃时,神经纤维的阻断阈值降低。研究结果将为相关的动物实验和功能电刺激的临床应用提供更多的信息。

Based on the McNeal cable model, taking the myelinated nerve fiber with limited length as the research object, this paper investigated the possibility and regularity of nerve conduction block with a monopolar point electrode using asymmetry bipbasic pulses. The results show that axons of different diameters （2 -20μm） can be blocked completely when the stimulation frequency is above 9kHz. At higher frequency a higher, stimulation intensity is needed to block nerve conduction. Larger diameter axons have lower block threshold . When the electrode-axon distance gets further, the stimulation intensity needed to block the propagation of action potential is higher. The block threshold is also influenced by the temperature, the block intensity gets lower when temperature is increased from 20℃ （ laboratory temperature） to 37℃ （ body temperature）. This simulation study can provide more information for animal experiments as well as clinical applications of electrical nerve block.