Qualia Oto, Inc., Dallas, TX, United States of America.
Department of Bioengineering, Phil and Penny Knight Campus for Accelerating Scientific Impact, University of Oregon, Eugene, OR, United States of America.
J Neural Eng. 2024 Nov 28;21(6). doi: 10.1088/1741-2552/ad9404.
. Kilohertz (kHz) frequency stimulation has gained attention as a neuromodulation therapy in spinal cord and in peripheral nerve block applications, mainly for treating chronic pain. Yet, few studies have investigated the effects of high-frequency stimulation on the performance of the electrode materials. In this work, we assess the electrochemical characteristics and stability of sputtered iridium oxide film (SIROF) microelectrodes under kHz frequency pulsed electrical stimulation.. SIROF microelectrodes were subjected to 1.5-10 kHz pulsing at charge densities of 250-1000C cm(25-100 nC phase), under monopolar and bipolar configurations, in buffered saline solution. The electrochemical behavior as well as the long-term stability of the pulsed electrodes was evaluated by voltage transient, cyclic voltammetry, and electrochemical impedance spectroscopy measurements.. Electrode polarization was more pronounced at higher stimulation frequencies in both monopolar and bipolar configurations. Bipolar stimulation resulted in an overall higher level of polarization than monopolar stimulation with the same parameters. In all tested pulsing conditions, except one, the maximum cathodal and anodal potential excursions stayed within the water window of iridium oxide (-0.6-0.8 V vs Ag|AgCl). Additionally, these SIROF microelectrodes showed little or no changes in the electrochemical performance under continuous current pulsing at frequencies up to 10 kHz for more than 10pulses.e. Our results suggest that 10 000mSIROF microelectrodes can deliver high-frequency neural stimulation up to 10 kHz in buffered saline at charge densities between 250 and 1000C cm(25-100 nC phase).
千赫兹（kHz）频率刺激作为脊髓和周围神经阻滞应用中的神经调节治疗方法引起了关注，主要用于治疗慢性疼痛。然而，很少有研究调查高频刺激对电极材料性能的影响。在这项工作中，我们评估了溅射氧化铱薄膜（SIROF）微电极在 kHz 频率脉冲电刺激下的电化学特性和稳定性。在缓冲盐溶液中，SIROF 微电极在单极和双极配置下以 250-1000C cm(25-100 nC 相)的电荷密度经受 1.5-10 kHz 的脉冲。通过电压瞬变、循环伏安法和电化学阻抗谱测量评估了脉冲电极的电化学行为和长期稳定性。在单极和双极配置下，在较高的刺激频率下，电极极化更为明显。在相同参数下，双极刺激比单极刺激导致更高的整体极化水平。在所有测试的脉冲条件下，除了一种情况外，最大阴极和阳极电位偏移都保持在氧化铱的水窗内（-0.6-0.8 V 对 Ag|AgCl）。此外，在高达 10 kHz 的频率下，这些 SIROF 微电极在连续电流脉冲下连续 10 次以上的情况下，电化学性能几乎没有变化或没有变化。我们的结果表明，在 250 至 1000C cm(25-100 nC 相)的电荷密度下，10000mSIROF 微电极可以在缓冲盐水中提供高达 10 kHz 的高频神经刺激。
