Eyes

Similar to the cochlear implant, an intact nervous system is required.

Better 'bionic eye' offers new hope of restored vision

14:39 16 February 2007

NewScientist.com news service

Gaia Vince

Trials of the new retinal prosthesis will begin shortly, following the success of a prototype that has enabled six blind people to see again. The prototypes were fitted in 2002 to patients who had lost their sight entirely.

If the trial is successful, the new device may be available commercially by 2009, priced around $30,000 - similar to a cochlear implant,

http://technology.newscientist.com/article.ns?id=dn11200

Retinal Implant Helps Restore Vision

This prothesis links with the ganglion cells at the back of the eye and the signals travel over the optic nerve to the brain.

After a prototype was successfully used in six people, further trials are set to begin.

The device is still preliminary; the resolution is quite limited, naturally. But it is interesting that the brains of the patients seem to adapt to the limited visual input, and their vision improved over time.

http://imparo.wordpress.com/2007/02/19/retinal-implant-helps-restore-vision/

See the following picture of a bionic eye implant

How the bionic eye implant works

The system has several components. The user wears a pair of glasses with a built-in camera. The information is then transmitted to a wireless computer around the size of a mobile telephone that the user must keep with him.

See the following diagram on “How the bionic eye implant works”

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/02/17/nsight17.xml

The Artificial Synapse Chip: A Flexible Retinal Interface Based on Directed Retinal Cell Growth and Neurotransmitter Stimulation

Mark C. Peterman, †Neville Z. Mehenti, ‡Kalayaan V. Bilbao, †Christina J. Lee,

‡Theodore Leng, ‡Jaan Noolandi, †Stacey F. Bent, ‡Mark S. Blumenkranz,

and ‡Harvey A. Fishman

The Artificial Synapse Chip is an evolving design for a flexible retinal interface that aims to improve visual resolution of an electronic retinal prosthesis by addressing cells individually and mimicking the physiological stimulation achieved in synaptic transmission. We describe three novel approaches employed in the development of the Artificial Synapse Chip: (i) micropatterned substrates to direct retinal cell neurite growth to individual stimulation sites; (ii) a prototype retinal interface based on localized neurotransmitter delivery; and (iii) the use of soft materials to fabricate these devices.

we have fabricated and implanted an equivalent device using soft flexible materials that conform to the retinal tissue more effectively. As many of the current retinal prosthesis devices use hard materials and electrical excitation at a lower resolution, our approach may provide more physiologic retinal stimulation.

http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1525-1594.2003.07307.x?cookieSet=1

Sensors Skip the Eyes, Go Straight to the Brain

By Brandon Keim April 26, 2007 | 11:51:31 AM

Several types of sight-boosting prostheses are currently under development, with some already being tested in humans.

Harvard researchers chose to focus on part of the visual system called the lateral geniculate nucleus (LGN), a relay station along the route from the optic nerve to the visual cortex, where visual information is processed.

See the following diagram of a sight-boosting prostheses.

http://blog.wired.com/wiredscience/2007/04/sensors_skip_th.html

Retinal implants may soon restore lost vision

The chip in the eye connects via a wire underneath the skin to a processor implanted behind the ear

Two millimeters in diameter and thinner than a human hair, the Optobionics implant is covered with microscopic solar cells. They gather energy from incoming light, without the need for wiring or external power sources, said Jacek Kotowski, medical director at Optobionics. No artificial image-processing is needed because the chip is meant to stimulate photoreceptors that might still be alive in the retina, keeping them awake.

http://news.zdnet.com/2100-9595-6057581.html

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