Spatial spread of neural excitation in cochlear implant recipients: comparison of improved ECAP method and psychophysical forward masking
Spatial spread of neural excitation in cochlear implant recipients: comparison of improved ECAP method and psychophysical forward masking
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DOI：
10.1016/s0378-5955(03)00096-0
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发表时间：
2003-05-01
期刊：
影响因子：
2.8
通讯作者：
Cowan, RSC
中科院分区：
文献类型：
--
作者：
Cohen, LT;Richardson, LM;Cowan, RSC
这项研究介绍并评估了一种使用神经响应遥测(TM)D系统(NRT(TM))测量电诱发神经兴奋在耳蜗内的纵向扩散的方法，该系统可与Nucleus(TM)24人工耳蜗植入系统一起使用。最近发布的NRT软件版本(3.0版)可以在不同的电极上显示“掩蔽器”和“探头”。在本方法中，探头位置是固定的，而掩模位置在电极阵列上是变化的。对部分屏蔽的探头的响应的幅度提供了掩蔽量的测量，这取决于掩蔽器和探头的激发区域的重叠程度。这些测量是在7个植入Nucleus 24人工耳蜗系统的受试者身上进行的(4个是直形的，3个是Conour(TM)电极阵列)，分别是基极、中极和尖端的探头电极。使用标准的NRT减法范例或另一种‘Miller’方法获得了相似的激发曲线。将激发曲线与心理物理前向掩蔽的结果进行了比较，发现两者吻合较好。电诱发复合动作电位(ECAP)和前掩蔽曲线的宽度没有显著差异。而ECAP测量的宽度与最大舒适度和电极带到蜗牛的距离显著相关，而前掩蔽轮廓的宽度与之无关。(C)2003 Elsevier Science B.V.保留所有权利。
This study introduces and evaluates a method for measurement of the longitudinal spread of electrically evoked neural excitation in the cochlea, using the Neural Response Telemetry(TM) D system (NRT(TM)) available with the Nucleus(TM) 24 cochlear implant system. The recently released version of the NRT software (version 3.0) enables presentation of the 'masker' and 'probe' on different electrodes. In the present method the probe position was fixed, while the masker position was varied across the electrode array. The amplitude of the response to the partially masked probe provides a measure of the amount of masking, which is dependent on the extent of overlap of the excitation regions of the masker and probe. These measurements were performed in seven subjects implanted with the Nucleus 24 cochlear implant system (four with straight and three with Contour(TM) electrode arrays), for basal, middle and apical probe electrodes. Similar excitation profiles were obtained using either the standard NRT subtraction paradigm or an alternative 'Miller' method. The excitation profiles were compared with those obtained from psychophysical forward masking and good agreement was found. The widths of electrically evoked compound action potential (ECAP) and forward masking profiles did not differ significantly. Whereas the width of the ECAP measure was significantly correlated with both the maximum comfortable level and the distance of the electrode band from the modiolus, the width of the forward masking profile was not. (C) 2003 Elsevier Science B.V. All rights reserved.