Despite many advances in the development of retinal prostheses, clinical reports show that current retinal prosthesis subjects can only perceive prosthetic vision with poor visual acuity. A possible approach for improving visual acuity is to produce virtual electrodes (VEs) through electric field modulation. Generating controllable and localized VEs is a crucial factor in effectively improving the perceptive resolution of the retinal prostheses. In this paper, we aimed to design a microelectrode array (MEA) that can produce converged and controllable VEs by current steering stimulation strategies. Through computational modeling, we designed a three-dimensional concentric ring–disc MEA and evaluated its performance with different stimulation strategies. Our simulation results showed that electrode–retina distance (ERD) and inter-electrode distance (IED) can dramatically affect the distribution of electric field. Also the converged VEs could be produced when the parameters of the three-dimensional MEA were appropriately set. VE sites can be controlled by manipulating the proportion of current on each adjacent electrode in a current steering group (CSG). In addition, spatial localization of electrical stimulation can be greatly improved under quasi-monopolar (QMP) stimulation. This study may provide support for future application of VEs in epiretinal prosthesis for potentially increasing the visual acuity of prosthetic vision.

中文翻译：

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基于建模研究的三维微电极阵列生成视网膜前假体虚拟电极

尽管视网膜假体的发展取得了许多进展，但临床报告表明，目前的视网膜假体受试者只能感知视力较差的假体视力。提高视力的一种可能方法是通过电场调制产生虚拟电极 (VE)。生成可控和局部的 VE 是有效提高视网膜假体感知分辨率的关键因素。在本文中，我们旨在设计一种微电极阵列 (MEA)，该微电极阵列 (MEA) 可以通过当前的转向刺激策略产生收敛和可控的 VE。通过计算建模，我们设计了一个三维同心圆盘 MEA，并评估了其在不同刺激策略下的性能。我们的模拟结果表明，电极-视网膜距离 (ERD) 和电极间距离 (IED) 可以显着影响电场的分布。当适当设置三维MEA的参数时，也可以产生收敛的VE。VE 位点可以通过控制电流控制组 (CSG) 中每个相邻电极上的电流比例来控制。此外，在准单极（QMP）刺激下，电刺激的空间定位可以大大改善。该研究可能为未来在视网膜前假体中应用 VE 提供支持，以潜在地提高假体视力的视力。当适当设置三维MEA的参数时，也可以产生收敛的VE。VE 位点可以通过控制电流控制组 (CSG) 中每个相邻电极上的电流比例来控制。此外，在准单极（QMP）刺激下，电刺激的空间定位可以大大改善。该研究可能为未来在视网膜前假体中应用 VE 提供支持，以潜在地提高假体视力的视力。当适当设置三维MEA的参数时，也可以产生收敛的VE。VE 位点可以通过控制电流控制组 (CSG) 中每个相邻电极上的电流比例来控制。此外，在准单极（QMP）刺激下，电刺激的空间定位可以大大改善。该研究可能为未来在视网膜前假体中应用 VE 提供支持，以潜在地提高假体视力的视力。