Bionic eye for treating blindness
by Nigel Lovell
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This silicon chip, encapsulated in ceramic and with a
100-wire electrode array attached, is to be surgically
implanted in the eyeball. The whole device is about the
size of a five-cent piece.
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A joint research team led by UNSW’s Associate Professor
Nigel Lovell and the University of Newcastle’s Dr Gregg
Suaning, has taken major steps towards producing a bionic
eye for the treatment of blindness, with the development of
a silicon chip that replaces the sensory part of the eye —
the retina.
The chip would be implanted inside the body and connected
into the nervous system through miniature platinum electrodes.
The device receives signals from a pair of glasses fitted
with a camera and worn by the patient.
The camera feeds the visual information into a separate
imageprocessing unit, which makes ‘sense’ of the
image by extracting certain features. It might find a door,
for example, by contrasting the bright open door with a dark
room.
The unit then breaks down the image into pixels and sends
the information, one pixel at a time, to the implanted silicon
chip, which then reconstructs the image. Electronic impulses
from the chip are used to stimulate 100 unique sites on the
retina. It is hoped these excited nerves will send signals
to the brain to give the sensation of sight.
The chip also includes a two-way radio communication system
that allows visual perceptions. However, whether these perceptions
could be interpreted in the human brain as useful vision remains
to be shown. The team is now looking towards short-term testing
in human patients in 2003. If the trials are successful, a
commercially available device would still be five to ten years
away.
Likely candidates for future ‘bionic eye’ technology
would be people with progressive eye diseases that lead to
loss of vision, like retinitis pigmentosa and age-related
macular degeneration, but who were born with vision and therefore
have the necessary brain pathways established for processing
visual information, unlike those who were born blind.
For further information, please contact Associate Professor
Nigel Lovell at N.Lovell@unsw.edu.au
or visit the website at bionic.gsbme.unsw.edu.au
