Visual cortex responses to suprachoroidal electrical stimulation of the retina: effects of electrode return configuration
Visual cortex responses to suprachoroidal electrical stimulation of the retina: effects of electrode return configuration
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DOI：
10.1088/1741-2560/9/3/036009
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发表时间：
2012-06-01
影响因子：
4
通讯作者：
Williams, Chris E.
中科院分区：
文献类型：
--
作者：
Cicione, Rosemary;Shivdasani, Mohit N.;Williams, Chris E.
临床上有效的视网膜假体必须响应于每个视网膜电极的刺激以视网膜定位方式唤起局部光幻视，在宽动态范围内唤起亮度提示，并在安全刺激限制内起作用。视网膜刺激的不同返回配置的影响目前尚不清楚。为了研究这一点，我们植入了一个灵活的，7 × 12电极阵列到脉络膜上腔的正常视力，麻醉猫。使用各种返回配置：单极玻璃体（MPV）、共同接地（CG）、六边形（HX）、单极远程（MPR）和双极（BPN）记录初级视皮层中响应于电刺激的多单位活动。MPV刺激被认为是最有效的充电，是最有可能在安全充电范围内诱导皮质活动。HX和CG刺激被发现表现出更大的视网膜选择性相比，MPV返回的代价是较低的皮质产量和较高的P50电荷水平，而皮质选择性不受返回的选择。使用MPR和宽间距BPN配置的响应与使用MPV返回的响应相似。这些结果表明，视网膜假体的返回配置的选择将在安全充电限制内的分辨率和刺激之间进行平衡。
A clinically effective retinal prosthesis must evoke localized phosphenes in a retinotopic manner in response to stimulation of each of the retinal electrodes, evoke brightness cues over a wide dynamic range and function within safe stimulus limits. The effects of varying return configuration for retinal stimulation are currently unknown. To investigate this, we implanted a flexible, 7 x 12 electrode array into the suprachoroidal space of normally-sighted, anesthetized cats. Multi-unit activity in the primary visual cortex was recorded in response to electrical stimulation using various return configurations: monopolar vitreous (MPV), common ground (CG), hexagonal (HX), monopolar remote (MPR) and bipolar (BPN). MPV stimulation was found to be the most charge efficient and was most likely to induce cortical activity within safe charge limits. HX and CG stimulation were found to exhibit greater retinal selectivity compared to the MPV return at the expense of lower cortical yield and higher P50 charge levels, while cortical selectivity was unaffected by choice of return. Responses using MPR and widely spaced BPN configurations were similar to those using the MPV return. These results suggest that choice of return configuration for a retinal prosthesis will be balanced between resolution and stimulation within safe charge limits.