Objective. We derive and demonstrate how residual voltage (RV) from a biphasic electrical stimulation pulse can be used to recognize degradation at the electrode-tissue interface. Approach. Using a first order model of the electrode-tissue interface and a rectangular biphasic stimulation current waveform, we derive the equations for RV as well as RV growth over several stimulation pulses. To demonstrate the use of RV for damage detection, we simulate accelerated damage on sputtered iridium oxide film (SIROF) electrodes using potential cycling. RV measurements of the degraded electrodes are compared against standard characterization methods of cyclic voltammetry and electrochemical impedance spectroscopy. Main results. Our theoretical discussion illustrates how an intrinsic RV arises even from perfectly balanced biphasic pulses due to leakage via the charge-transfer resistance. Preliminary data in in-vivo rat experiments follow the derived model of RV growth, thereby validating our hypothesis that RV is a characteristic of the electrode-tissue interface. RV can therefore be utilized for detecting damage at the electrode. Our experimental results for damage detection show that delamination of SIROF electrodes causes a reduction in charge storage capacity, which in turn reflects a measurable increase in RV. Significance. Chronically implanted electrical stimulation systems with multi-electrode arrays have been the focus of physiological engineering research for the last decade. Changes in RV over time can be a quick and effective method to identify and disconnect faulty electrodes in large arrays. Timely diagnoses of electrode status can ensure optimal long term operation, and prevent further damage to the tissue near these electrodes.

客观的。我们推导并演示了如何使用双相电刺激脉冲的残余电压 (RV) 来识别电极-组织界面处的退化。方法。使用电极-组织界面的一阶模型和矩形双相刺激电流波形，我们推导出 RV 以及多个刺激脉冲上 RV 生长的方程。为了演示使用 RV 进行损伤检测，我们使用电位循环模拟溅射氧化铱膜 (SIROF) 电极的加速损伤。将退化电极的 RV 测量值与循环伏安法和电化学阻抗谱的标准表征方法进行比较。主要结果。我们的理论讨论说明了即使由于电荷转移电阻的泄漏，即使是完美平衡的双相脉冲也会产生内在的 RV。体内大鼠实验的初步数据遵循 RV 生长的衍生模型，从而验证了我们的假设，即 RV 是电极-组织界面的特征。因此，RV 可用于检测电极处的损坏。我们的损伤检测实验结果表明，SIROF 电极的分层导致电荷存储容量降低，这反过来又反映了 RV 的可测量增加。意义。在过去十年中，具有多电极阵列的长期植入电刺激系统一直是生理工程研究的重点。RV 随时间的变化可以是一种快速有效的方法来识别和断开大型阵列中的故障电极。及时诊断电极状态可以确保最佳的长期操作，并防止对这些电极附近的组织造成进一步的损害。