Effects of Asymmetric Electrical Pulse on Retinal Excitement for Retinal Prostheses
Effects of Asymmetric Electrical Pulse on Retinal Excitement for Retinal Prostheses
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DOI：
10.18494/sam.2018.1701
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发表时间：
2018-01-01
影响因子：
1.2
通讯作者：
Fujikado, Takashi
中科院分区：
文献类型：
--
作者：
Nakano, Yukari;Terasawa, Yasuo;Fujikado, Takashi
用于失明的视网膜假体通过电刺激视网膜，使感光细胞变性，从而引起伪光感（光幻觉）。具有电荷平衡的双相对称脉冲通常用于视网膜假体中的电刺激。据报道，电荷平衡双相不对称脉冲可以降低人工耳蜗中电诱发反应的阈值。在这项研究中，为了确定不对称脉冲的有效性，我们将单相双相对称和不对称脉冲经视网膜应用于麻醉大鼠的眼球。我们发现，与具有相同电荷的对称脉冲相比，应用持续时间较短和电流幅度较高的阳极脉冲会在上丘（SC）中引起大的场响应。该结果表明，阳极相中具有短脉冲持续时间和高电流幅度的不对称脉冲比具有相同电荷的对称脉冲对于视网膜假体更有效。
Retinal prostheses for blindness electrically stimulate retinas with photoreceptor cell degeneration to evoke a pseudolight sensation (phosphenes). Biphasic symmetric pulses with charge balancing are commonly used for electrical stimulation in retinal prostheses. It has been reported that a charge-balanced biphasic asymmetric pulse can reduce the threshold for electrical evoked responses in cochlear implants. In this study, in order to determine the effectiveness of an asymmetric pulse, we applied single biphasic symmetric and asymmetric pulses transretinally to the eyeball of anesthetized rats. We found that the application of an anodal pulse with a shorter duration and a higher current amplitude evoked a large field response in the superior colliculus (SC) in comparison with a symmetric pulse with the same electrical charge. This result suggests that an asymmetric pulse with a short pulse duration and high current amplitude in the anodal phase is more effective for retinal prostheses than a symmetrical pulse with the same electrical charge.