Research And Testing System On Flexible Microelectrode Arrays Of Epiretinal Prosthesis

Vision is the most important means of one's accessing to outside information.Blindness not only affect patients' quality of life, but also brings heavy burden to government and society.Blindness may be caused by damage to any stage(s) along the visual pathway, such as cortical, optic nerve, and retinal. The Implantation of Micro device to restore the sight could be a potential solution. The microelectrodes, by which the charges are injected into the visual cortex, retina or optic nerve, serve as the interface between the electronics and the biological tissue and are the key component of the visual prosthesis. Therefore, to study the property of the neuro-stimulating microelectrodes is of significant importance in the vision rehabilitation research.In this paper, we explained the theoretical research and the current status of visual prosthesis. We also analyzed several kinds of implantable neuro- stimulating electrode arrays. In order to meet research needs, we proposed a new design on dual-layer flexible microelectrode arrays (MEA) of epiretinal prosthesis, and we also design some modules and operation procedures to conserve, encapsulate and test the MEAs. The basic theory of electrode-electrolyte electrochemical process and the equivalent electrical circuit was studied in this paper, and thereafter proposed the precise three-electrode system to test the electrode-electrolyte interface impedance. For the purpose of protecting the microelectrodes from injuries which may be derived from manual and repetitive operation, we built a set of automatic testing system to evaluate and analyze the MEA. By using this system, we could also generated a seperate datasheet for every MEA.