Use of cortical electrodes in solving visual prosthesis problems

There are two main approaches to visual function prosthesis in blindpatients with the use of brain-computer interfaces on the basisof either retinal or cortical stimulation by implanted electrodes. Themost complex in visual prosthesis is creation of the specific part ofthe interface that directly contacts with the tissues. In the paper discussed are questions of biocompatibility of microelectrode arraysand behavioral effects on animals (cats) for evaluating functionalityof the bioprosthetic device and its ability to induce phosphenes(visual sensations without light). Presented are new experimentalmethods and obtained results that allowed to determine phospheneinducing parameters of brain cortex electric stimulation in cats.Special attention is focused on description of the microelectrodearray properties necessary for safe application in humans during thelong time span, which is essential in cortical visual prosthesis.