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Photovoltaic Retinal Prosthesis

机译:光伏视网膜假体

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摘要

Electronic retinal prostheses seek to restore sight to patients suffering from retinal degenerative disorders. Implanted electrode arrays apply patterned electrical stimulation to surviving retinal neurons, producing visual sensations. All current designs employ inductively coupled coils to transmit power and/or data to the implant. We present here the design and initial testing of a photovoltaic retinal prosthesis fabricated with a pixel density of up to 177 pixels/mm2. Photodiodes within each pixel of the subretinal array directly convert light to stimulation current, avoiding the use of bulky coil implants, decoding electronics, and wiring, and thereby reducing surgical complexity. A goggles-mounted camera captures the visual scene and transmits the data stream to a pocket processor. The resulting images are projected into the eyes by video goggles using pulsed, near infrared (-900 nm) light. Prostheses with three pixel densities (15,55, and 177 pix/mm2) are being fabricated, and tests indicate a charge injection limit of 1.62 mC/cm2 at 25Hz. In vitro tests of the photovoltaic retinal stimulation using a 512-element microelectrode array have recorded stimulated spikes from the ganglion cells, with latencies in the 1-100ms range, and with peak irradiance stimulation thresholds varying from 0.1 to 1 mW/mm2. With lms pulses at 25Hz the average irradiance is more than 100 times below the IR retinal safety limit. Elicited retinal response disappeared upon the addition of synaptic blockers, indicating that the inner retina is stimulated rather than the ganglion cells directly, and raising hopes that the prosthesis will preserve some of the retina's natural signal processing.
机译:电子视网膜假体试图恢复患有视网膜退行性疾病的患者的视线。植入的电极阵列将图案化的电刺激施加到存活的视网膜神经元上,从而产生视觉感觉。当前所有的设计都采用电感耦合线圈来将功率和/或数据传输到植入物。我们在这里介绍了像素密度高达177像素/ mm2的光伏视网膜假体的设计和初始测试。视网膜下阵列的每个像素内的光电二极管将光直接转换为刺激电流,从而避免了使用笨重的线圈植入物,解码电子设备和布线,从而降低了手术的复杂性。装有护目镜的摄像机捕获视觉场景并将数据流传输到袖珍处理器。产生的图像通过使用脉冲近红外(-900 nm)光的视频护目镜投影到眼睛中。正在制造具有三个像素密度(15、55和177 pix / mm2)的假体,测试表明在25Hz时的电荷注入极限为1.62 mC / cm2。使用512元素微电极阵列进行的光伏视网膜刺激的体外测试已记录了神经节细胞的刺激尖峰,潜伏期在1-100ms范围内,峰值辐照刺激阈值从0.1到1 mW / mm2不等。对于25Hz的lms脉冲,平均辐照度比IR视网膜安全极限低100倍以上。加入突触阻滞剂后,消失的视网膜反应消失,这表明内部视网膜被刺激而不是神经节细胞被直接刺激,并提出了假体将保留视网膜某些自然信号处理的希望。

著录项

  • 来源
    《Ophthalmic technologies XXI》|2011年|p.788513-1-788513-13|共13页
  • 会议地点 San Francisco CA(US)
  • 作者单位

    Depts. of aApplied Physics, Stanford University, 450 Serra Mall, Stanford University, Stanford, CA, USA 94305;

    Dept. of Physics and Astronomy, University of Glasgow, G12 8QQ, Glasgow, UK;

    Depts. of Electrical Engineering, Stanford University, 450 Serra Mall, Stanford University, Stanford, CA, USA 94305;

    Depts. of Electrical Engineering, Stanford University, 450 Serra Mall, Stanford University, Stanford, CA, USA 94305;

    Depts. of Electrical Engineering, Stanford University, 450 Serra Mall, Stanford University, Stanford, CA, USA 94305;

    et al;

  • 会议组织
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 眼科学;
  • 关键词

    retinal prosthesis; photodiode; neural stimulation; neurophysiology; electrophysiology;

    机译:视网膜假体光电二极管神经刺激神经生理学电生理;

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