Real-Time Optimization of Retinal Ganglion Cell Spatial Activity in Response to Epiretinal Stimulation.
Real-Time Optimization of Retinal Ganglion Cell Spatial Activity in Response to Epiretinal Stimulation.
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DOI：
10.1109/tnsre.2021.3138297
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Weiland JD
中科院分区：
文献类型：
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作者：
Haji Ghaffari D;Akwaboah AD;Mirzakhalili E;Weiland JD
视网膜假体旨在改善因感光细胞变性而失明的患者的视觉感知。然而，由于空间分辨率低，这些设备的形状和字母感知目前受到限制。先前的研究表明，视网膜神经节细胞（RGC）的空间活动和光幻视的形状可以由于视网膜结构和电极-视网膜相互作用的复杂性而变化。对于同一对象内的不同电极，单个电极引起的视觉感知在尺寸和形状上不同，导致光幻视之间的干扰和不清晰的图像。先前的工作表明，更好的患者结果与空间分离的光幻视相关。在这项研究中，我们使用钙成像，在体外视网膜，神经网络（NN），和优化算法，以证明一种方法来迭代搜索最佳的刺激参数，创造局灶性RGC激活。我们的研究结果表明，我们可以收敛到刺激参数，导致局灶性RGC激活采样不到1/3的参数空间。临床上实施的类似过程可以减少优化植入手术所需的时间，并实现视网膜假体的个性化拟合。
Retinal prostheses aim to improve visual perception in patients blinded by photoreceptor degeneration. However, shape and letter perception with these devices is currently limited due to low spatial resolution. Previous research has shown the retinal ganglion cell (RGC) spatial activity and phosphene shapes can vary due to the complexity of retina structure and electrode-retina interactions. Visual percepts elicited by single electrodes differ in size and shapes for different electrodes within the same subject, resulting in interference between phosphenes and an unclear image. Prior work has shown that better patient outcomes correlate with spatially separate phosphenes. In this study we use calcium imaging, in vitro retina, neural networks (NN), and an optimization algorithm to demonstrate a method to iteratively search for optimal stimulation parameters that create focal RGC activation. Our findings indicate that we can converge to stimulation parameters that result in focal RGC activation by sampling less than 1/3 of the parameter space. A similar process implemented clinically can reduce time required for optimizing implant operation and enable personalized fitting of retinal prostheses.