Comparison of Signal and Gap-Detection Thresholds for Focused and Broad Cochlear Implant Electrode Configurations
Comparison of Signal and Gap-Detection Thresholds for Focused and Broad Cochlear Implant Electrode Configurations
复制标题
DOI：
10.1007/s10162-015-0507-y
复制
发表时间：
2015-04-01
影响因子：
2.4
通讯作者：
Carlyon, Robert P.
中科院分区：
文献类型：
--
作者：
Bierer, Julie Arenberg;Deeks, John M.;Carlyon, Robert P.
人工耳蜗术(CI)患者通常在“聚焦”刺激模式下表现出明显的跨电极检测阈值差异，例如部分三极(PTP)模式。这可能反映了局部神经存活或电极到蜗牛的距离的差异。为了阐明这两种解释，我们使用1031-PPS脉冲串，对10名Advanced Bionics CI用户每人至少四个电极的刺激检测阈值和缺口检测阈值(GDT)进行了舒适的大声比较。在PTP模式下，为每个用户选择的电极具有广泛的刺激检测阈值。我们还在单极(MP)模式下测量了刺激检测任务和间隙检测任务中的跨电极差异。刺激检测阈值和间隙检测阈值在不同模式下都是相关的。然而，在这两种模式下，刺激检测阈值和缺口检测阈值之间都没有显著的相关性。因此，间隙检测阈值可能会利用刺激检测阈值所揭示的跨电极变异的来源，或者不同于刺激检测阈值所揭示的来源。在两种模式下，心尖电极的刺激检测阈值明显低于基底电极；只有在PTP模式下的间隙检测才是如此。最后，虽然刺激检测阈值的跨电极标准差在PTP模式下比在MP模式下更大，但这些差异的可靠性--通过将跨电极标准偏差除以每个电极的自适应运行的标准偏差--对于两种模式是相似的；对于间隙检测，这种度量在模式之间也是相似的。因此，使用临床上可用的MP刺激可以揭示跨电极的差异，其可靠性与使用聚焦刺激观察到的可靠性相当。
Cochlear implant (CI) users usually exhibit marked across-electrode differences in detection thresholds with "focused" modes of stimulation, such as partial-tripolar (pTP) mode. This may reflect differences either in local neural survival or in the distance of the electrodes from the modiolus. To shed light on these two explanations, we compared stimulus-detection thresholds and gap-detection thresholds (GDTs) at comfortably loud levels for at least four electrodes in each of ten Advanced Bionics CI users, using 1031-pps pulse trains. The electrodes selected for each user had a wide range of stimulus-detection thresholds in pTP mode. We also measured across-electrode variations in both stimulus-detection and gap-detection tasks in monopolar (MP) mode. Both stimulus-detection and gap-detection thresholds correlated across modes. However, there was no significant correlation between stimulus-detection and gap-detection thresholds in either mode. Hence, gap-detection thresholds likely tap a source of across-electrode variation additional to, or different from, that revealed by stimulus-detection thresholds. Stimulus-detection thresholds were significantly lower for apical than for basal electrodes in both modes; this was only true for gap detection in pTP mode. Finally, although the across-electrode standard deviation in stimulus-detection thresholds was greater in pTP than in MP mode, the reliability of these differences-assessed by dividing the across-electrode standard deviation by the standard deviation across adaptive runs for each electrode-was similar for the two modes; this metric was also similar across modes for gap detection. Hence across-electrode differences can be revealed using clinically available MP stimulation, with a reliability comparable to that observed with focused stimulation.