27-12-2012, 03:01 PM
PRESENTATION ON BIONIC EYE
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ABSTRACT
Here, we present a description of a block
scheme, specific features of design and results
of testing for a prototype of a bionic eye, types
of them and its applications. The bionic eye is
intended to provide vision, partially to the
visually impaired by use of the modern day
electronics devices like CCD cameras. The
comprises a computer chip that sits in the back
of the individual's eye, linked up to a mini
video camera built into glasses that they wear.
Images captured by the camera are beamed to
the chip, which translates them into impulses
that the brain can interpret. Although the
images produced by the artificial eye were far
from perfect, they could be clear enough to
allow someone who is otherwise blind to
recognize faces. The paper discusses the
differences working methodologies used in
each of them. During the tests and the clinical
trails, this device made six blind people to
regain their vision partially. The potential
advantage of using bionic eye is to be able to
remove the blindness completely by making
the advances in the present research and
improving manufacturing technologies. This
break through is likely to benefit
approximately one crore world population
who suffer from the most common causes of
blindness, Retinitis Pigmentosa, Macular
Degeneration. The implant bypasses the
diseased cells in the retina and stimulates the
remaining viable cells. This is a revolutionary
piece of technology and really has the
potential to change people's lives. But we need
to be aware it is still some way in the future.
INTRODUCTION
A visual prosthesis or bionic eye is a form
of neural prosthesis intended to partially
restore lost vision or amplify existing vision.
It usually takes the form of an externallyworn
camera that is attached to a stimulator
on the retina, optic nerve, or in the visual
cortex, in order to produce perceptions in the
visual cortex.
These experimental visual devices are
modeled on the cochlear implant or bionic
ear devices, a type of neural prosthesis in
use since the mid 1980s. These are an
externally-worn microphone and processor
that is attached to a stimulator in the
cochlea, auditory nerve, in order to produce
sound perception in the auditory cortex.
ACTUAL EYE SYSTEM
Our ability to see is the result of a process
similar to that of a camera. In a camera, light
passes through a series of lenses that focus
images onto film or an imaging chip. The
eye performs a similar function in that light
passes through the cornea and crystalline
lens, which together focus images onto the
retina—the layer of light sensing cells that
lines the back of the eye.
Once stimulated by light, the cells within
the retina process the images by converting
their analog light signals into digital electrochemical
pulses that are sent via the optic
nerve to the brain. A disruption or
malfunction of any of these processes can
result in loss of vision.
How an Artificial Retina Works
Normal vision begins when light enters and
moves through the eye to strike specialized
photoreceptor (light-receiving) cells in the
retina called rods and cones. These cells
convert light signals to electric impulses that
are sent to the optic nerve and the brain.
Retinal diseases like age-related macular
degeneration and retinitis pigmentosa
destroy vision by annihilating these cells.
The Bionic Eye System
The entire system runs on a battery pack
that's housed with the video processing unit.
When the camera captures an image -- of,
say, a tree -- the image is in the form of light
and dark pixels. It sends this image to the
video processor, which converts the treeshaped
pattern of pixels into a series of
electrical pulses that represent "light" and
"dark." The processor sends these pulses to a
radio transmitter on the glasses, which then
transmits the pulses in radio form to a
receiver implanted underneath the subject's
skin. The receiver is directly connected via a
wire to the electrode array implanted at the
back of the eye, and it sends the pulses down
the wire.
CONCLUSION
Its been 40 years since Arne Larsson
received the first fully implanted
cardiac pacemaker at the Karolinska
Institute in Stockholm.
Researchers throughout the world
have looked for ways to improve
people's lives with artificial, bionic
devices.
Bionic devices are being developed
to do more than replace defective
parts.
Researchers are also using them to
fight illnesses.
Providing power to run bionic
implants and making connections to
the brain's control system pose the
two great challenges for biomedical
engineering.