Modelling encapsulation tissue around cochlear implant electrodes
Modelling encapsulation tissue around cochlear implant electrodes
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DOI：
10.1007/bf02345122
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发表时间：
2005-01-01
影响因子：
3.2
通讯作者：
Hanekom, T
中科院分区：
文献类型：
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作者：
Hanekom, T
本研究旨在探讨纤维瘢痕组织包裹电极对电位分布和听神经纤维兴奋模式的影响。有限元模型结合听觉神经纤维模型被用来预测阈值电流和听觉神经纤维兴奋模式的变化。该模型表明，在存在包囊组织的情况下，靶神经纤维和电极触点处的电位发生变化。这导致了阈值电流的变化和激励的传播。电极封装对阈值电流和兴奋传播的影响取决于将纤维组织封装和电极阵列分开的外淋巴层的厚度、神经纤维存活状态、电极几何形状和配置以及阵列位置。模型结果表明，位于蜗轴附近的阵列对由电极封装引起的阈值变化最敏感（变化在-0.26和2.41 dB之间），而当阵列位于鼓阶的侧位时，电极阵列的封装对阈值电流的影响较小（变化在-0.64和1.5 dB之间）。对于位于内侧的阵列，在激发的传播变化之间的增加0.21毫米和减少0.33毫米沿着长度的基底膜，和0.18毫米的增加和减少0.66毫米沿着长度的基底膜计算为位于外侧的阵列。
The objective of the study was to explore the effect of electrode encapsulation by fibrous scar tissue on electrical potential distributions and auditory nerve fibre excitation patterns. A finite element model in combination with an auditory nerve fibre model was used to predict changes in threshold currents and auditory nerve fibre excitation patterns. The model showed that electrical potentials at the target nerve fibres and the electrode contacts changed in the presence of encapsulation tissue. This led to changes in threshold currents and spread of excitation. The effect of electrode encapsulation on threshold currents and spread of excitation depended on the thickness of the perilymph layer separating the fibrous tissue encapsulation and the electrode array, nerve fibre survival status, electrode geometry and configuration, and array location. Model results suggested that arrays located close to the modiolus were most sensitive to threshold changes caused by electrode encapsulation (changes were between -0.26 and 2.41 dB), whereas encapsulation of an electrode array had less effect on threshold currents when the array was located in a lateral position in the scala tympani (changes were between -0.64 and 1.5dB). For medially located arrays, changes in the spread of excitation varied between an increase of 0.21 mm and a decrease of 0.33 mm along the length of the basilar membrane, and an increase of 0.18 mm and a decrease of 0.66 mm along the length of the basilar membrane were calculated for laterally located arrays.