刺激脉宽对电诱发复合动作电位阈值的影响

Effect of Stimulating Pulse Width on the Threshold of Electrically Evoked Compound Action Potential

本文研究了电诱发复合动作电位(ECAP)的刺激脉宽与阈值之间的关系。首先通过对已有实验结果的拟合得到了单根听神经动作电位的刺激脉宽和阈值关系式中的基强度和时基;而后基于ECAP的机制提出了一个描述其刺激脉宽与阈值之间关系的数学表达式;进一步通过豚鼠实验得到了表达式的参数并验证了表达式的适用性。研究结果表明,ECAP与单根听神经动作电位对比,二者的刺激脉宽与阈值之间存在相似的函数关系,但前者的基强度比后者小一个数量级,而时基比较接近。这些结果对于临床的ECAP测量与深入研究人工耳蜗的语音处理策略具有一定的指导意义。

This paper discusses the relationship between stimulating pulse width and the threshold of electrically evoked compound action potential （ECAP）. Firstly, the rheobase and chronaxy from strength-duration curve of nerve fiber was computed using the shepherd＇s experiment results. Secondly, based on the relationship between ECAP and the action potential of nerve fiber, a mathematical expression to describe the relationship between stimula- ting pulse width and ECAP threshold was proposed. Thirdly, the parameters were obtained and the feasibility was proved to the expression with the results of experiment using guinea pigs. Research result showed that with ECAP compared to the action potential of nerve fiber, their threshold function relationship with stimulating pulse width was similar, and rheobase from the former was an order smaller in the magnitude than the latter, but the chronaxy was close to each other. These findings may provide meaningful guidance to clinical ECAP measurement and studying speech processing strategies of cochlear implant.