Lee S, Ahn J, Yoo H, Jung S, Oh S, Park S, Cho D
Annu Int Conf IEEE Eng Med Biol Soc. 2013;2013:3535-8. doi: 10.1109/EMBC.2013.6610305.
In order to provide high quality visual information to patients who have implanted retinal prosthetic devices, the number of microelectrode should be large. As the number of microelectrode is increased, the dimension of the microelectrode is decreased, which in turn results in the increased interface impedance of microelectrode and decreased dynamic range of injection current. In addition, the reduced maximum limit of injection current may not be sufficiently large to stimulate the ganglion cells in a retina. In order to improve the trade-off envelope between number of microelectrode and current injection limit, a 3D microelectrode structure can be used as an alternative. From the advancement of microfabrication technology, the fabrication of highly-accurate 3D structures with small dimensions is possible. This paper presents a first comprehensive electrical characterization of 2D and 3D microelectrodes for high-resolution retinal prostheses. Microelectrodes which differ in shapes and diameters are analyzed. Their interface impedances and charge injection limits are quantitatively analyzed. This research can be used to define requirements for further retinal prosthetic device research.
为了向植入视网膜假体装置的患者提供高质量视觉信息，微电极的数量应较多。随着微电极数量的增加，微电极的尺寸会减小，这反过来会导致微电极的界面阻抗增加，注入电流的动态范围减小。此外，注入电流的最大限制降低可能不足以充分刺激视网膜中的神经节细胞。为了改善微电极数量与电流注入限制之间的权衡关系，可以使用三维微电极结构作为替代方案。随着微制造技术的进步，制造具有小尺寸的高精度三维结构成为可能。本文首次对用于高分辨率视网膜假体的二维和三维微电极进行了全面的电学特性分析。分析了形状和直径不同的微电极。对它们的界面阻抗和电荷注入限制进行了定量分析。这项研究可用于确定进一步的视网膜假体装置研究的要求。
