Resolution of the epiretinal prosthesis is not limited by electrode size.
Resolution of the epiretinal prosthesis is not limited by electrode size.
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DOI：
10.1109/tnsre.2011.2140132
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发表时间：
2011-08
期刊：
影响因子：
--
通讯作者：
Weiland JD
中科院分区：
文献类型：
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作者：
Behrend MR;Ahuja AK;Humayun MS;Chow RH;Weiland JD
用于盲人的视网膜前假体绕过视网膜中的病变感光细胞，直接电刺激视网膜神经元并唤起传递到大脑的信号。目前的临床植入物具有很少的电极并且提供有限的视觉灵敏度。可以通过识别增强或干扰视觉感知形成的电极阵列设计特征和操作细节来提高敏锐度。我们用钙报告分子标记了整个视网膜中的所有视网膜神经节细胞，然后在一定范围的电极直径和刺激持续时间内测量了细胞响应的数量和模式。对于60 μm及更大的电极，响应范围与电极直径成比例。短刺激脉冲宽度选择性地激活最接近电极的细胞。我们在蝾螈视网膜上的测量表明，空间分辨率为150 μm，相当于人类视网膜上的0.55°视野和相应的Snellen视力为20/660。有了这样的假肢，阅读大字体是可能的。
Epiretinal prostheses for the blind bypass diseased photosensitive cells in the retina, directly stimulating retinal neurons electrically and evoking signals that are relayed to the brain. Current clinical implants have few electrodes and provide limited visual acuity. Acuity may be improved by identifying electrode array design features and operational details that enhance or interfere with visual percept formation. We labeled all retinal ganglion cells in whole mount retina with a calcium reporter and then measured the number and pattern of cells responding, over a range of electrode diameters and stimulus durations. Span of the response scaled with electrode diameter for electrodes 60 μm and larger. Short stimulation pulse widths selectively activated cells nearest the electrode. Our measurements in the salamander retina suggest that the spatial resolution is 150 μm, which on a human retina is equivalent to 0.55° of human visual field and corresponding Snellen acuity of 20/660. Reading large print could be possible with such a prosthesis.