Photovoltaic restoration of sight in animals blinded by retinal degeneration
Abstract/Contents
- Abstract
- Retinal degenerative diseases, such as age-related macular degeneration and retinitis pigmentosa, are the leading untreatable cause of blindness in the world. In these diseases, the progressive demise of the image-capturing photoreceptors renders the eye unable to translate visual information into neural signals. However, to a large extent, the image-processing inner retinal neurons survive the degeneration process. Building up on the success of cochlear prostheses, retinal prostheses aim at partial restoration of sight by electrical stimulation of these surviving neurons. While several types of retinal implants demonstrated their ability to elicit percepts of light in blind patients, they suffer from a number of shortcomings. Power cables and bulky intraocular electronics make the implantation procedure very difficult, prone to complications, and the devices often fail over time. Visual percepts are frequently distorted, spatial resolution is low, and patients report only a very limited number of levels of gray. This work presents the design and characterization of a fully wireless subretinal visual prosthesis, in which photovoltaic pixels are activated by pulsed near infrared light (880-915 nm). Pixels that are 140 µm and 70 µm-wide safely elicit retinal and cortical responses both in-vitro and in-vivo in animal models of retinal degeneration. Network-mediated retinal stimulation is highly localized, restoring up to half the normal spatial resolution in blind rats, and geometrically translating to the spatial resolution expected from a person with 20/250 visual acuity. Furthermore, it preserves many features of natural vision, including flicker fusion, adaptation to static images and transient responses to changes in luminance. We conclude by describing the contrast sensitivity of prosthetic vision, and show how image processing prior to projection onto the implant can enhance system performance.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2015 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Goetz, Georges Armand |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Palanker, Daniel |
| Thesis advisor | Palanker, Daniel |
| Thesis advisor | Chichilnisky, E. J |
| Thesis advisor | Wandell, Brian A |
| Advisor | Chichilnisky, E. J |
| Advisor | Wandell, Brian A |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Georges Armand Goetz. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2015. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2015 by Georges Armand Goetz
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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