ECAP信号伪迹与人工耳蜗阻抗模型电学组件之间的关联

文献信息

中文摘要

电诱发复合动作电位（ECAP）是临床实践中可用的少数客观听觉神经活动测量方法之一，可为患者的神经状态提供有价值的见解。ECAP记录通常使用不同的电极进行刺激和记录，以避免电极极化引起的放大器饱和。然而，同电极记录可减少神经激活部位与记录部位之间的空间分离，可能提供更局部的神经活动评估，并提高基于ECAP的生物标志物的敏感性。在此，我们介绍一种利用先前发表的阻抗模型来表征刺激伪迹并估计其参数的方法。伪迹波形由共享的双指数函数描述，而等效电路的电学组件则通过使用多个脉冲持续时间获取的阻抗测量来估计。伪迹记录表现出明显的极性依赖性行为。尽管如此，快速指数分量的幅度与其基于阻抗的估计值显示出显著关联（阳极-阴极和阴极-阳极刺激的固定效应系数分别为β=0.37和β=0.44；p<0.001）。此外，快速指数分量的纵向变化与近场阻抗子组件的变化相似，提示ECAP伪迹可能部分受到电极-电解质界面术后变化的影响。

英文摘要

electrically evoked compound action potentials (ECAPs) are among the few objective measures of auditory nerve activity available in clinical practice and provide valuable insight into a patient's neural status. ECAP recordings are typically performed using different electrodes for stimulation and recording to avoid amplifier saturation caused by electrode polarization. However, same-electrode recording could reduce the spatial separation between the site of neural activation and the recording site, potentially providing a more localized assessment of neural activity and improving the sensitivity of ECAP-based biomarkers. Here, we introduce a method to characterize stimulation artifacts and estimate their parameters using a previously published impedance model. The artifact waveform was described by a shared double exponential function, while electrical components of an equivalent circuit were estimated from impedance measurements acquired with multiple pulse durations. Artifact recordings exhibited clear polarity-dependent behavior. Nevertheless, the amplitude of the fast exponential component showed a significant association with its impedance-based estimate (fixed-effect coefficient β=0.37 and β=0.44 for anodic-cathodic and cathodic-anodic stimulation, respectively; p<0.001). Furthermore, longitudinal changes in the fast exponential component were similar to changes in near-field impedance subcomponent, suggesting that the ECAP artifact could be partially influenced by postoperative changes at the electrode-electrolyte interface.