Developing an Intra-cortical Visual Prosthesis
The goal of any sensory neural prosthesis is to transmit information from an artificial sensor (e.g. video camera, microphone) directly to the part of the brain that normally receives such information from the corresponding biological sensor (e.g. eye, ear). The past 30 years has seen the development of technologies and experimental surgeries towards the goal of implementing a cortical visual prosthesis for restoration of vision in individuals with blindness. Despite some key successes, communication of continuous visual sensory information to the cortex of a human subject has not yet been demonstrated. For this to be effective, electrical stimulation must be applied in a well-controlled temporo-spatial pattern that mimics the pattern of neural activity normally associated with the biological sensory information, and exploits the natural tuning of the neurological system. Our efforts are focused on development of a cortical visual prosthesis using large numbers of intra-cortical micro-electrodes that penetrate the visual cortex. Although significant advances in electrode technology and establishment of criteria for safe stimulation in the cortex have been realized, the integration of electrodes into reliable, interconnected multi-channel arrays, implantable multi-channel stimulators, and the fundamental visual science studies to determine the potential functional usefulness of an intra-cortical prosthesis are lacking. An essential component of a visual prosthesis system is the translation of electronic-based image information into electrical signals that communicate the visual perception to the cortex.
The overall objectives of our multi-institutional team-based project are to advance the technology sufficiently to provide a reasonable expectation of reliability and safety for implantable hardware, and to develop an animal model to perform crucial psychophysical and electrical stimulation studies, so that a multi-model decision process about proceeding to human volunteer can be defined. We plan that our program will converge in an analysis of data from the fundamental electrical stimulation and psychophysical studies of the animal model, and the development of a completely implantable multi-channel stimulation system, including chronically implantable stimulation electrodes.
Dr. Troyk is
on the faculty of the Pritzker Institute of Bionedical Science and
Engineering, IIT, and is director of the Neural Engineering Program
which offers a Ph.D. in Biomedical Engineering in cooperation with the
Committee on Computational Neuroscience at the