Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Geneva, 1202, Switzerland.
J Neural Eng. 2022 May 27;19(3). doi: 10.1088/1741-2552/ac6d7e.
Intraneural nerve interfaces often operate in a monopolar configuration with a common and distant ground electrode. This configuration leads to a wide spreading of the electric field. Therefore, this approach is suboptimal for intraneural nerve interfaces when selective stimulation is required.We designed a multilayer electrode array embedding three-dimensional concentric bipolar (CB) electrodes. First, we validated the higher stimulation selectivity of this new electrode array compared to classical monopolar stimulation using simulations. Next, we compared themby intraneural stimulation of the rabbit optic nerve and recording evoked potentials in the primary visual cortex.Simulations showed that three-dimensional CB electrodes provide a high localisation of the electric field in the tissue so that electrodes are electrically independent even for high electrode density. Experimentshighlighted that this configuration restricts spatial activation in the visual cortex due to the fewer fibres activated by the electric stimulus in the nerve.Highly focused electric stimulation is crucial to achieving high selectivity in fibre activation. The multilayer array embedding three-dimensional CB electrodes improves selectivity in optic nerve stimulation. This approach is suitable for other neural applications, including bioelectronic medicine.
神经内接口通常采用单极配置，共用一个远离的地电极。这种配置会导致电场的广泛扩散。因此，当需要选择性刺激时，这种方法对于神经内接口并不是最优的。我们设计了一种多层电极阵列，其中嵌入了三维同心双极 (CB) 电极。首先，我们通过模拟验证了这种新电极阵列比传统的单极刺激具有更高的刺激选择性。接下来，我们通过在兔视神经内刺激和在初级视觉皮层记录诱发电位来进行比较。模拟表明，三维 CB 电极在组织中提供了电场的高定位，因此即使在高电极密度下，电极也是电独立的。实验表明，由于电刺激在神经中激活的纤维较少，这种配置限制了视觉皮层中的空间激活。高度聚焦的电刺激对于实现纤维激活的高选择性至关重要。嵌入三维 CB 电极的多层阵列可提高视神经刺激的选择性。这种方法适用于其他神经应用，包括生物电子医学。
