Intracortical multiunit implant to create vision for blinds : Integration and validation

美国合法失明人数超过100万，其中约10%的人完全看不到光。该项目旨在回答大规模视觉假体使用直接电刺激为盲人创造视觉的基本问题。几个研究小组已经选择设计视觉假体。对视网膜或视神经的电刺激可以用来逆转由视网膜色素变性等疾病或甚至年龄相关性黄斑变性引起的视网膜外部退化所导致的视力丧失。然而，这些技术对影响内层或全层视网膜或视神经的疾病没有帮助，对失明的情况也没有帮助。然而，这种疾病可以通过使用皮质内视觉假体来逆转。植入视觉皮质的电极矩阵被用来创建由一系列视觉感知或膦组成的视觉图像。这个拟议项目的起点是一个完善的初步设计，其中包括已经在传统电子测试台上制造和测试的ASIC。正在进行的工作涉及四个不同和互补的方面，即1)建模、刺激技术和参数，2)植入实施和优化，包括电极矩阵制造和设备封装，3)外部控制器，包括图像采集和处理，以及4)慢性动物体内植入和测试。我们希望为有效、安全和有效的皮质慢性刺激提供一套参数。由于该项目涉及设备的实际植入，一个重要的目标是确定可靠的手术技术和最佳的设备物理特性，并获得关于小型化和组装的技术诀窍。我们还旨在通过使用先进的采集和处理技术来最大限度地利用设备，这涉及到在高效和低功耗设备上设计和集成图像传感器、处理算法和硬件。

The number of legally blind Americans exceeds 1 million with around 10% of them having no perception of light whatsoever. This project is intended to answer the fundamental questions of creating vision for blinds using direct electrical stimulation for large scale visual prostheses. Several research groups have opted to design visual prostheses. Electrical stimulation of the retina or of the optic nerve can be used to reverse the loss of sight induced by outer retinal degeneration caused by diseases the likes of retinitis pigmentosa or even by age-related macular degeneration. These techniques, however, are not helpful for the case of diseases affecting the inner or whole thickness retina or the optic nerve, nor as well for the case of eye loss. Such diseases, nonetheless, can be reversed by using intracortical visual prostheses. Matrices of electrodes implanted in the visual cortex are used to create a visual image consisting of an array of visual perceptions, or phosphenes. The starting point of this proposed project is a well-established preliminary design which includes ASICs that have already been fabricated and tested on conventional electronic test benches. The ongoing work tackles four different and complementary facets of the problem, namely 1) Modeling, stimulation techniques and parameters, 2) implant implementation and optimization, including electrode matrices fabrication and device encapsulation, 3) an external controller, including image acquisition and processing, and 4) in-vivo implantation in chronic animal and testing. We wish to provide sets of parameters for efficient, safe and effective chronic stimulation of the cortex. As the project involves actual implantation of devices, one important objective is to define reliable surgical techniques and optimal device physical characteristics and to acquire know-how regarding miniaturization and assembly. We also aim at maximizing the exploitation of the device by using advanced acquisition and processing techniques, which involve the design and integration of image sensors, processing algorithms and hardware on efficient and low power devices.