Kang Soojin, Chwodhury Tanmoy, Moon Il Joon, Hong Sung Hwa, Yang Hyejin, Won Jong Ho, Woo Jihwan
School of Electrical Engineering, Biomedical Engineering, University of Ulsan, Ulsan 680-749, Republic of Korea.
Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University, Seoul 330-714, Republic of Korea.
Comput Math Methods Med. 2015;2015:934382. doi: 10.1155/2015/934382. Epub 2015 Feb 10.
A cochlear implant (CI) is an auditory prosthesis that enables hearing by providing electrical stimuli through an electrode array. It has been previously established that the electrode position can influence CI performance. Thus, electrode position should be considered in order to achieve better CI results. This paper describes how the electrode position influences the auditory nerve fiber (ANF) response to either a single pulse or low- (250 pulses/s) and high-rate (5,000 pulses/s) pulse-trains using a computational model. The field potential in the cochlea was calculated using a three-dimensional finite-element model, and the ANF response was simulated using a biophysical ANF model. The effects were evaluated in terms of the dynamic range, stochasticity, and spike excitation pattern. The relative spread, threshold, jitter, and initiated node were analyzed for single-pulse response; and the dynamic range, threshold, initiated node, and interspike interval were analyzed for pulse-train stimuli responses. Electrode position was found to significantly affect the spatiotemporal pattern of the ANF response, and this effect was significantly dependent on the stimulus rate. We believe that these modeling results can provide guidance regarding perimodiolar and lateral insertion of CIs in clinical settings and help understand CI performance.
人工耳蜗（CI）是一种听觉假体，通过电极阵列提供电刺激来实现听力。先前已经确定电极位置会影响人工耳蜗的性能。因此，为了获得更好的人工耳蜗效果，应考虑电极位置。本文使用计算模型描述了电极位置如何影响听神经纤维（ANF）对单个脉冲或低频率（250脉冲/秒）和高频率（5000脉冲/秒）脉冲序列的反应。使用三维有限元模型计算耳蜗中的场电位，并使用生物物理ANF模型模拟ANF反应。从动态范围、随机性和尖峰激发模式方面评估这些效应。分析了单脉冲反应的相对扩散、阈值、抖动和起始节点；并分析了脉冲序列刺激反应的动态范围、阈值、起始节点和峰间期。发现电极位置会显著影响ANF反应的时空模式，并且这种影响显著依赖于刺激速率。我们认为这些建模结果可以为临床环境中人工耳蜗的蜗周和外侧插入提供指导，并有助于理解人工耳蜗的性能。
