Attracting retinal cells to electrodes for high-resolution stimulation
Attracting retinal cells to electrodes for high-resolution stimulation
复制标题
将视网膜细胞吸引到电极上以进行高分辨率刺激
DOI：
10.1117/12.529757
复制
发表时间：
2004
影响因子：
1.6
通讯作者：
M. Blumenkranz
中科院分区：
文献类型：
--
作者：
D. Palanker;P. Huie;A. Vankov;Yev Freyvert;H. Fishman;M. Marmor;M. Blumenkranz
开发用于使患有退行性视网膜疾病的患者恢复视力的电子视网膜假体面临着许多技术挑战。为了使低视力患者获得显着改善，视力需要达到 20/80，这对应于视网膜植入物中 20μm 的像素尺寸。强烈（二次）刺激电流取决于电极和细胞之间的距离。为了实现刺激阈值的均匀性，避免电极腐蚀和组织过热，并减少相邻像素之间的串扰，神经细胞与电极的距离不应超过几微米。沿着植入物的整个表面实现如此紧密的接近是高分辨率视网膜植入物的主要障碍之一。为了确保细胞和电极的接近，我们开发了一种促进视网膜细胞向刺激部位迁移的技术。该装置由多层膜组成，膜上有一系列直径为数（5-15）微米的穿孔，可在其中嵌入可寻址电极。在使用 P7 大鼠整个视网膜外植体的体外实验以及使用成年兔子和 RCS 大鼠的体内实验中，当膜位于视网膜下侧时，视网膜组织生长到孔中。组织学证明，迁移细胞保留了与孔外细胞的突触连接，从而允许信号转导到植入物上方的视网膜。通过该技术实现细胞与电极的紧密接近，可以将 10μm 电极处的刺激电流减少至 2μA。具有 18,000 个像素的 3mm 磁盘阵列可以以 50Hz 的 0.5 ms 脉冲刺激细胞，同时将植入物表面的温升保持在 0.3°C 以下。原则上，这种植入物可以提供与10°视野中20/80的视力相对应的几何空间分辨率。
Development of the electronic retinal prosthesis for restoration of sight in patients suffering from the degenerative retinal diseases faces many technological challenges. To achieve significant improvement in the low vision patients the visual acuity of 20/80 would be desirable, which corresponds to the pixel size of 20μm in the retinal implant. Stimulating current strongly (quadratically) depends on distance between electrode and cell. To achieve uniformity in stimulation thresholds, to avoid erosion of the electrodes and overheating of tissue, and to reduce the cross-talk between the neighboring pixels the neural cells should not be separated from electrodes by more than a few micrometers. Achieving such a close proximity along the whole surface of an implant is one of the major obstacles for the high resolution retinal implant. To ensure proximity of cells and electrodes we have developed a technique that prompts migration of retinal cells towards stimulating sites. The device consists of a multilayered membrane with an array of perforations of several (5-15) micrometers in diameter in which addressable electrodes can be embedded. In experiments in-vitro using explants of the whole retina of P7 rats, and in-vivo using adult rabbits and RCS rats the retinal tissue grew into the pores when membranes were positioned on the sub-retinal side. Histology has demonstrated that migrating cells preserve synaptic connections with cells outside the pores, thus allowing for signal transduction into the retina above the implant. Intimate proximity of cells to electrodes achieved with this technique allows for reduction of the stimulation current to 2μA at the 10μm electrode. A 3mm disk array with 18,000 pixels can stimulate cells with 0.5 ms pulses at 50Hz while maintaining temperature rise at the implant surface below 0.3°C. Such an implant can, in principle, provide spatial resolution geometrically corresponding to the visual acuity of 20/80 in a visual field of 10°.
暗适应虎蝾螈视网膜中杆状和锥状双极细胞突触的响应灵敏度和电压增益。
DOI：
10.1152/jn.1997.78.5.2662
发表时间：
1997
期刊：
Journal of neurophysiology.
影响因子：
--
作者：
Yang,XL;Wu,SM
通讯作者：
Wu,SM
视网膜脱离引起的视网膜内增殖。
影响因子：
4.4
作者：
Fisher,SK;Erickson,PA;Lewis,GP;Anderson,DH
通讯作者：
Anderson,DH