24 July 2009

On the way to the electronic eye

Electronics restored sight to the blindAlexey Timoshenko, GZT.RU
Scientists at the California University of Technology have managed to create a prosthesis capable of performing the functions of the retina in cases of its damage.

While using it, a person sees an image in the form of a blurry picture. But a more advanced version of the prosthesis is already being prepared.

For their work as one of the 100 best inventions of the year, the team of researchers received an award from R&D Magazine. The prosthesis is designed in such a way that a camera is fixed on the frame of the glasses, the image from which is transmitted directly to the surviving neurons in the retina of the eye.

On the way to the electronic eyeIn order to create a video camera with retinal functions, scientists and doctors had to overcome many different problems.

So, the eye, unlike the camera with its matrix of photosensitive elements, has its own nervous system, which carries out the preliminary processing of information. And this process in the eye is organized differently in comparison with the functions of the processor in the video camera.

In addition, nerves are not just conductors like electrical wires. The propagation of the pulse through them is not electromagnetic, but chemical in nature, so it turned out to be very difficult to connect them.

Scientists had to create a special processor capable of translating a standard video signal into a series of pulses perceived by nerve cells. And only then it was the turn of surgeons, who implanted microelectrodes into the retina of the eye for the first 29 patients so that the signal reached their own nerve cells. The work was done with jewelry precision. But, despite this, after the operation, the camera processor had to be further adjusted, ensuring that it transmitted the correct image to the person, and, for example, did not flip the picture and did not change its parts in places.

Pixels The picture that patients with implanted artificial retina saw is still far from perfect.

A mosaic of 16 or even 60 squares (the best result for today) could be completely useless, but the prosthesis already allows you to distinguish light from darkness and at least avoid major obstacles in the course of the patient's movement. Further improvement of the technology will certainly improve the image quality, which will allow people with damaged retinas to see at close range and, if they do not return to work requiring good eyesight, then at least move freely through the streets without guides.

Image from the press release of the California University of Technology.
This is how a patient will see a person who has been implanted with electrodes from a camera and a special processor instead of the affected retinal cells.

Retinal lesionHowever, the method has some limitations.

Firstly, it must be borne in mind that retinal surgery is always a very complex surgical intervention in the body. Secondly, all the operated patients suffered damage to the retina during the aging process, without affecting the nerve cells of the eye. If microsurgery patients had a damaged optic nerve or there were no nerve cells in the retina of the eye from birth, the new development of scientists and doctors would be meaningless. However, progress in the field of microelectronics, growing knowledge about the work of the eye and the creation of new materials for microelectrodes allow us to hope that sooner or later most of the currently incurable lesions will at least be compensated with prosthetics.

Portal "Eternal youth" http://vechnayamolodost.ru24.07.2009

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