Estimation of phosphene spatial variability for visual prosthesis applications.

Visual prostheses are the focus of intensive research efforts to restore some measure of useful vision to blind or near-blind patients. The development of such technology is being guided to an extent by tools that simulate prosthesis behavior for healthy sighted subjects in order to assess system requirements and configurations. These simulators, however, typically assume purely deterministic phosphene properties and thus do not apply any variability to phosphene size, intensity, or location. We address this issue by presenting data on phosphene variability measured in a blind human subject fitted with an optic nerve prosthesis. In order to correct for normal limitations in human-pointing accuracy, the experimental conditions were repeated with sighted subjects. We conclude that identical optic nerve stimulations can result in phosphenes whose perceived locations vary by up to 5 degrees of deviation angle and 10 degrees of position angle. The consistency of phosphenes presented in the peripheral field of view can vary by an additional 3 degrees.

[1]  E Zrenner,et al.  Retinal prosthesis: an encouraging first decade with major challenges ahead. , 2001, Ophthalmology.

[2]  C. Veraart,et al.  Creating a meaningful visual perception in blind volunteers by optic nerve stimulation , 2005, Journal of neural engineering.

[3]  S. Kelly,et al.  Perceptual efficacy of electrical stimulation of human retina with a microelectrode array during short-term surgical trials. , 2003, Investigative ophthalmology & visual science.

[4]  U. Leonards,et al.  Simulation of artificial vision: I. Eccentric reading of isolated words, and perceptual learning , 2003, Vision Research.

[5]  G.J. Suaning,et al.  Learning prosthetic vision: a virtual-reality study , 2005, IEEE Transactions on Neural Systems and Rehabilitation Engineering.

[6]  James Gordon,et al.  Accuracy of planar reaching movements , 1994, Experimental Brain Research.

[7]  P. O. Bishop,et al.  Some quantitative aspects of the cat's eye: axis and plane of reference, visual field co‐ordinates and optics , 1962, The Journal of physiology.

[8]  Benoît Gérard,et al.  Pattern recognition with the optic nerve visual prosthesis. , 2003, Artificial organs.

[9]  K W Horch,et al.  Reading speed with a pixelized vision system. , 1992, Journal of the Optical Society of America. A, Optics and image science.

[10]  Eduardo Fernandez,et al.  Toward the development of a cortically based visual neuroprosthesis , 2009, Journal of neural engineering.

[11]  M. Mladejovsky,et al.  Artificial Vision for the Blind: Electrical Stimulation of Visual Cortex Offers Hope for a Functional Prosthesis , 1974, Science.

[12]  C. Veraart,et al.  Position, size and luminosity of phosphenes generated by direct optic nerve stimulation , 2003, Vision Research.

[13]  George E Stelmach,et al.  Pointing to an Allocentric and Egocentric Remembered Target in Younger and Older Adults , 2004, Experimental aging research.

[14]  K. Horch,et al.  Mobility performance with a pixelized vision system , 1992, Vision Research.

[15]  G. Cosnard,et al.  Intraorbital implantation of a stimulating electrode for an optic nerve visual prosthesis. Case report. , 2006, Journal of neurosurgery.

[16]  J. Mortimer,et al.  Visual sensations produced by optic nerve stimulation using an implanted self-sizing spiral cuff electrode , 1998, Brain Research.

[17]  Benoît Gérard,et al.  Object localization, discrimination, and grasping with the optic nerve visual prosthesis. , 2006, Restorative neurology and neuroscience.

[18]  Avi Caspi,et al.  Feasibility study of a retinal prosthesis: spatial vision with a 16-electrode implant. , 2009, Archives of ophthalmology.

[19]  Melvyn A. Goodale,et al.  The effects of landmarks on the performance of delayed and real-time pointing movements , 2005, Experimental Brain Research.

[20]  Yves Rossetti,et al.  Effects of Visual Deprivation on Space Representation: Immediate and Delayed Pointing toward Memorised Proprioceptive Targets , 2006, Perception.

[21]  Gislin Dagnelie,et al.  Facial recognition using simulated prosthetic pixelized vision. , 2003, Investigative ophthalmology & visual science.

[22]  N H Lovell,et al.  A CMOS retinal neurostimulator capable of focussed, simultaneous stimulation , 2009, Journal of neural engineering.

[23]  Gislin Dagnelie,et al.  Visually guided performance of simple tasks using simulated prosthetic vision. , 2003, Artificial organs.

[24]  G. Brindley,et al.  The sensations produced by electrical stimulation of the visual cortex , 1968, The Journal of physiology.

[25]  Gislin Dagnelie,et al.  Visual perception in a blind subject with a chronic microelectronic retinal prosthesis , 2003, Vision Research.

[26]  Nigel H. Lovell,et al.  Simulated prosthetic visual fixation, saccade, and smooth pursuit , 2005, Vision Research.

[27]  B. Rappaz,et al.  Simulation of artificial vision: II. Eccentric reading of full-page text and the learning of this task , 2004, Vision Research.

[28]  A. Y. Chow,et al.  The artificial silicon retina microchip for the treatment of vision loss from retinitis pigmentosa. , 2004, Archives of ophthalmology.

[29]  C Veraart,et al.  The microsystems based visual prosthesis for optic nerve stimulation. , 2002, Artificial organs.