Transcript VISUAL PROSTHESIS

VISUAL PROSTHESIS
By Richard Jones
and David Henley
OVERVIEW
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Various methods of helping (partially) blind
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Brain implant
Seeing with sound
Eye implant
The First Useful Artificial Eye
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First implanted in 1978
Allowed ‘Jerry’ to see shades
of grey
– Whilst connected to a 10ft
by 7ft, 2 ton computer
Now computer weighs 5kg,
and Jerry sees phosphenes
Edge detection algorithms applied to images from camera
‘Jerry’ can navigate New York subway
Very limited field of view
Neural Implants
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Camera mounted on glasses
Computer converts signals
into a form that can be
‘understood’ by the brain
Signal passes down wires
into the skull
Connect to an electrode array on the surface of the visual
cortex.
Since the 1950s it has been known that stimulating the visual
cortex produces phosphenes
The Second Generation
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Costs $80,000 US
Percutaneous
pedestals - were
sunk into both sides
of Jens skull
Connected to platinum
electronic arrays
lying on surface of
visual cortex
Phosphene images had to be mapped
He drove a car
Alternative methods
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Implant described sits on top of the visual
cortex
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Many neurons are stimulated at once
Richard Normann, is working on device
that will be implant into the visual cortex
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Lower voltages required, so safer
Much more accurate
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Potential to stimulate individual neurons
vOICe DEVICE
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Visual Cortex can be stimulated by sound
Typically 4000 pixels (vocals) / sec
Perception 1000-4000
$2500 (exc training/adaptation)
Environment /web etc
HOW IT WORKS
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1) Left and Right
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2) Top and Bottom
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Scanning, stereo
Pitch = elevation
3) Dark and Light
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Loudness = brightness
EXAMPLE
Oscilloscope
other sound?
EXAMPLE 2
USER THOUGHTS
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A late-blinded user of The vOICe commented
on August 29, 2002, saying: ``Just sound?....
No, It is by far more, it is sight ! There IS true
light perception generated by the vOICe. When
I am not wearing the voice the light I perceive
from a small slit in my left eye is a grey fog.
When wearing the vOICe the image is light
with all the little greys and blacks. Yet a definite
light image .” …….
ADVANTAGES
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Cheap (1/10 implant cost)
Fewer risks
Quick
No implants, no electrodes, no surgery
Unobtrusive
DISADVANTAGES
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Cannot hear anything else
Limited information
Brain can only perceive so much sound
Training is equivalent to learning a foreign
language
EYE IMPLANT
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Artificial Retina
Optic nerves and ganglia are intact
Partially sighted
Infra-red positioning/info/power
EYE IMPLANT
EYE IMPLANT
EXAMPLE OF PIXELATION
CONCLUSON
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Field is advancing all the time
Three routes mentioned here have adv/disadv
Dr. Dobelle has predicted that guide dogs /
Braille will be obsolete by 2100
Geordi LaForge here we come!!!