22-05-2012, 01:50 PM
BIONIC EYE
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INTRODUCTION
A Bionic Eye is a device, which acts as an artificial eye. It is a broad term for the
entire electronics system consisting of the image sensors, processors, radio transmitters &
receivers, and the retinal chip. Based on the institute developed these devices are
developed but with minor to major differences, of these the devices with functional
capability and those which are clinically tested and results proved are discussed here.
Here the designer’s objective is to go for a system that is technically perfect with no loop
holes and that is harmless to the human body which receives the system and that is
commercially viable both in terms of ease of manufacture, cost and the process of
implanting.
Blindness means loss of vision. Rods and Cones, millions of them are in the back
of every healthy human eye. They are biological solar cells in the retina that convert light
to electrical impulses -- impulses that travel along the optic nerve to the brain where
images are formed. Without them, eyes lose the capacity to see, and are declared blind.
Degenerative retinal diseases result in death of photoreceptors--rod-shaped cells at the
retina's periphery responsible for night vision and cone-shaped cells at its center
responsible for color vision. Worldwide, 1.5 million people suffer from retinitis
pigmentosa (RP), the leading cause of inherited blindness. In the Western world, agerelated
macular degeneration (AMD) is the major cause of vision loss in people over age
65, and the issue is becoming more critical as the population ages. Each year, 700,000
people are diagnosed with AMD, with 10 percent becoming legally blind, defined by
20/400 vision. Many AMD patients retain some degree of peripheral vision.
Currently, there is no effective treatment for most patients with AMD and RP, the
researchers say . However, if one could bypass the photoreceptors and directly stimulate
the inner retina with visual signals, one might be able to restore some degree of sight.
Need for the BIONIC EYE:
It has been shown that electric stimulation of retinal neurons can produce
perception of light in patients suffering from retinal degeneration. Using this property the
eye and make uses of the functional cells to retain the vision with the help of electronic
devices that assist this cells in performing the task of vision, we can make these lakhs of
people get back their vision at least partially. A design of an optoelectronic retinal
prosthesis system that can stimulate the retina with resolution corresponding to a visual
acuity of 20/80—sharp enough to orient yourself toward objects, recognize faces, read
large fonts, watch TV and, perhaps most important, lead an independent life. The
researchers hope their device may someday bring artificial vision to those blind due to
retinal degeneration.
BIONIC EYE DEFINED:
Bionic Eye, Bio Electronic eye, is a device that can provide sight -- the
detection of light. It replaces the functionality of a part or whole of eye. it is used to
replace functionality as well as add functionality. It is a complex combination of
multiple devices which work together for restoration of the vision of the subject
The Diseases that cause blindness:
Retinitis Pigmentosa
Macular Degeneration
Of these, retinitis pigmentosa is a disease, which is a hereditary genetic disease in which
peripheral rods degenerate gradually progresses towards center of eye and results in
tunnel vision.
As for macular degeneration, it is also genetically related , it degenerates cones in
macula region, causing damage to central vision but spares peripheral retina.
MIT- HARVARD DEVICE:
This device follows an Epi-Retinal Approach. In this Microelectrode array
replaces damaged photoreceptors, which act in the place of rods and cones
to send the signals to optic nerve. The power source – Laser(820nm
wavelength). For image acquisition it uses a CCD Camera. Patient spectacle
holds the camera and power source.