Field patterns in a 3D tapered spiral model of the electrically stimulated cochlea
Field patterns in a 3D tapered spiral model of the electrically stimulated cochlea
复制标题
DOI：
10.1016/s0378-5955(00)00104-0
复制
发表时间：
2000-10-01
期刊：
影响因子：
2.8
通讯作者：
Frijns, JHM
中科院分区：
文献类型：
--
作者：
Briaire, JJ;Frijns, JHM
尽管耳蜗植入物在临床实践中得到了广泛而成功的应用，但迄今为止对它们在耳蜗中建立的电场模式知之甚少。基于现有的测量和建模结果，鼓阶通常被认为是一个优先的电流通路，其作用类似于泄漏的传输线。因此，大多数作者假设电流阈值沿鼓阶的长度沿着呈指数衰减。在这里，我们提出了一个完全三维的，螺旋体积传导模型的豚鼠耳蜗计算的电位分布，并试图确定其优先电流通路。相对良好的传导鼓阶事实上是主要的，但电流的指数衰减（J类似于e（-z））只是远场行为的一个很好的描述。在附近的电极，即附近的纤维，最容易激发，更高的电流密度被发现，这是最好的描述由球形传播的电流（J类似于1/R-2）的结果进行比较与我们以前的，旋转对称的，模型的变体，并与文献中的测量。根据模拟的神经反应的研究结果的影响进行了讨论。(C)2000 Elsevier Science B. V.保留所有权利。
Despite the fact that cochlear implants are widely and successfully used in clinical practice, relatively little is known to date about the electric field patterns they set up in the cochlea. Based upon the available measurements and modelling results, the scala tympani is usually considered to be a preferential current pathway that acts like a leaky transmission line. Therefore, most authors assume the current thresholds to decay exponentially along the length of the scala tympani. Here we present potential distributions calculated with a fully three-dimensional, spiralling volume conduction model of the guinea pig cochlea, and try to identify its preferential current pathways. The relatively well conducting scala tympani turns out to be the main one indeed, but the exponential decay (J similar to e(-z)) of current is only a good description of the far-field behaviour. In the vicinity of the electrodes, i.e. near the fibres that are most easily excited, higher current densities are found, that are best described by a spherical spread of the current (J similar to 1/R-2) The results are compared with those obtained with a variant of our previous, rotationally symmetric, model and with measurements in the literature. The implications of the findings are discussed in the light of simulated neural responses. (C) 2000 Elsevier Science B.V. All rights reserved.