Computer-Controlled Neurostimulation for a Visual Implant

Current research in therapies for restoring a functional form of sight to the blind includes interfacing electronic neurostimulators with some point of the visual pathway. This approach requires controlling a number of waveform parameters which might vary for every implanted patient and for every channel in an interface that may have hundred or thousands of electrodes. Therefore, the clinical, acute research stage of the implant should be controlled in a flexible and easy way, in order to obtain the information that will lead to a chronic implantable device. We describe such a system, based on a PC connected to an electronic neurostimulator, which delivers bi-phasic pulses to a set of implanted microelectrodes. This platform performs an automated patient-driven procedure to find stimulation thresholds. The system implements a set of physchophysical tests in order to determine the properties of the elicited visual perceptions, and applies an automatic re-mapping of the electrodes to obtain better recognizable patterns of percepts. Our platform can interface some other tools oriented to obtain, in a next research stage, a portable and chronic version of