Gregg J. Suaning

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In the last decade several groups have been developing vision prostheses to restore visual perception to the profoundly blind. Despite some promising results from human trials, further understanding of the neural mechanisms involved is crucial for improving the efficacy of these devices. One of the techniques involves placing stimulating electrodes in the(More)
A visual tracking task was administered to 20 subjects afforded simulated prosthetic vision (a phosphene array); a total of 3h data was taken from each subject over the course of 10 visits. The experiment assessed prosthetic visual fixation, saccade and smooth pursuit and the effect of practice. Further, we demonstrated an image analysis technique that(More)
PURPOSE Research to restore some degree of vision to patients suffering from retinal degeneration is becoming increasingly more promising. Several groups have chosen electrical stimulation of the remaining network of a degenerate retina as a means to generate discrete light percepts (phosphenes). Approaches vary significantly, with the greatest difference(More)
This paper presents the results of the first investigations into the use of bipolar electrical stimulation of the retina with a suprachoroidal vision prosthesis, and the effects of different electrode configurations on localization of responses on the primary visual cortex. Cats were implanted with electrodes in the suprachoroidal space, and electrically(More)
With increasing research advances and clinical trials of visual prostheses, there is significant demand to better understand the perceptual and psychophysical aspects of prosthetic vision. In prosthetic vision a visual scene is composed of relatively large, isolated, spots of light so-called "phosphenes", very much like a magnified pictorial print. The(More)
A virtual-reality simulation tested prosthetic visual acuity for both rectangular and hexagonal phosphene grids. Thirteen normally sighted, untrained subjects were required to identify the Landolt C optotype over ten sessions. Overall performance, performance by filter setting (image analysis), and performance by size and orientation of the Landolt C(More)
A new method for fabrication of microelectrode arrays comprised of traditional implant materials is presented. The main construction principle is the use of spun-on medical grade silicone rubber as insulating substrate material and platinum foil as conductor (tracks, pads and electrodes). The silicone rubber and the platinum foil are patterned by laser(More)
Several approaches have been proposed for placement of retinal prostheses: epiretinal, subretinal and suprachoroidal. We aimed to systematically evaluate the effectiveness of varying a range of stimulus parameters and electrode geometry for a suprachoroidal electrode array, using cortical evoked responses to monopolar electrical stimulation in cats. Our(More)
Conducting polymer (CP) coatings on medical electrodes have the potential to provide superior performance when compared to conventional metallic electrodes, but their stability is strongly dependant on the substrate properties. The aim of this study was to examine the effect of laser roughening of underlying platinum (Pt) electrode surfaces on the(More)
OBJECTIVE Visual prostheses currently in development aim to restore some form of vision to patients suffering from diseases such as age-related macular degeneration and retinitis pigmentosa. Most rely on electrically stimulating inner retinal cells via electrodes implanted on or near the retina, resulting in percepts of light termed 'phosphenes'. Activation(More)