The nerve-electrode interface of the cochlear implant: Current spread
The nerve-electrode interface of the cochlear implant: Current spread
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DOI：
10.1109/10.736751
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发表时间：
1999-01-01
影响因子：
4.6
通讯作者：
White, RL
中科院分区：
文献类型：
--
作者：
Liang, DH;Lusted, HS;White, RL
为了准确地预测电刺激对听神经的影响，必须了解人工耳蜗的一个基本方面是神经-电极界面。这个界面的一个方面是电极传递的电流扩散到远离它的神经元的程度。本文报告了使用来自猫听觉神经的单个单元的记录对这种电流传播的直接映射。不同单元对不同位置电极的选择性反应程度有很大的差异，根据它们对不同电极的选择性反应，可以在线性阵列中识别出三种类型的单元。第一类单元随着刺激点从鼓室的顶端向基底移动，其阈值逐渐增加；第二类单元表现出急剧的局部最小值，在最小值附近阈值迅速增加，超过6 dB/mm。在远离局部极小值的电极位置，阈值的变化率接近于第一类单元的变化率。最后一种类型的单元也表现出阈值随着电极位置的变化而逐渐变化，但是可以识别出两个局部极小值，一个是顶端的，一个是基部的。假设这三种类型对应于起源于顶端到电极阵列，沿着电极阵列和基部到电极阵列的单位。
One of the fundamental facets of the cochlear implant that must be understood to predict accurately the effect of an electrical stimulus on the auditory nerve is the nerve-electrode interface. One aspect of this interface is the degree to which current delivered by an electrode spreads to neurons distant from it. This paper reports a direct mapping of this current spread using recordings from single units from the cat auditory nerve.Large variations were seen in the degree to which the differ ent units are selective in responding to electrodes at different positions within the scala tympani, Three types of units could be identified based on the selectiveness of their response to the different electrodes in a linear array, The first type of unit exhibited a gradual increase in threshold as the stimulating site was moved from more apical to more basal locations within the scala tympani, The second type of unit exhibited a sharp local minimum, with rapid increases in threshold in excess of 6 dB/mm in the vicinity of the minimum. At electrode sites distant from the local minima the rate of change of the threshold approached that of the first type of units. The final type of unit also demonstrated a gradual change in threshold with changing electrode position, however, two local minima, one apical and one basal, could be identified.These three types are hypothesized to correspond to units which originate apical to the electrode array, along the electrode array and basal to the electrode array.