A Flexible Electrode Array for Acute In-Vitro Stimulating on Animal

Electrical stimulation of the remaining retinal neurons to restore useful vision has been recently proposed in patients with retinitis pigmentosa(RP) or age-related macular degeneration(AMD). A critical element of a retinal prosthesis is the stimulating electrode array, which is placed in close proximity to the retina. It is via the retinal-electrode interface that a retinal prosthesis electrically stimulates nerve cells to produce the perception of light. In this paper, a flexible flat electrode array was developed and used for this study. The electrode array is made of polymide and Au, which has excellent biocompatibility. Computer simulation is used to calculate the electric field by means of the finite element method. The impedance of the electrode array was measured. The electrode array was inserted into the suprachoroidal space in the posterior portion of the rabbit´s eye. For electrical stimulation, a biphasic pulse was used. When the electrical stimulation from the suprachoroidal space was applied, the EEP could be recorded with an epidural electrode.