From: Spudboy100@aol.com
Date: Mon Jan 17 2000 - 07:04:36 MST
http://news.bbc.co.uk/hi/english/sci/tech/default.htm
The first useful artificial eye is now helping a blind man walk safely around
and read large letters, researchers said on Monday.
The 62-year-old man, identified only as Jerry, demonstrated that he was able
to collect a black hat off a white wall, then locate a mannequin and place
the hat on its head.
The specks inside the box are what Jerry sees
Jerry, blinded by an accident at the age of 36, does not see an image but up
to 100 specks of light that appear and disappear as his field of vision
shifts. The specks show up the edges of objects. The constellation of dots,
called phosphenes, has been likened to stars that glitter and fade behind
passing clouds.
"He can do remarkably well," said William Dobelle, chairman of the Dobelle
Institute, the US medical device company that has developed the system.
Richard Normann, an artificial vision expert at the University of Utah,
stressed that the device is "a very limited navigational aid, and a far cry
from the visual experience that normal people enjoy".
However he added that the work suggests that even limited signals to the
brain will let blind people do relatively complicated visual tasks.
'Major step forward'
Dr Bill Heetderks, director of a US National Institutes of Health program to
develop electronic implants that work with the brain, believes an implant
that helps blind people navigate would be a major step forward.
"When Dr Dobelle provides additional details on his methodology that
establishes this result, we may be there," Dr Heetderks said. The device and
its performance are described in the January/February issue of the American
Society of Artificial Internal Organs Journal.
The artificial vision system works by taking an image from a miniature
television camera and distance information from an ultrasound sensor, each of
which is mounted on one lens of a pair of sunglasses.
These signals are processed by a five-kilogram (10 pounds) portable computer
and then a new signal is sent to 68 platinum electrodes implanted in the
person's brain. The electrodes are on the surface of the brain's visual
cortex and stimulate the person to 'see' the phosphenes.
Jerry has recognised five-centimetre-tall (two inches) letters from 1.5
metres (five feet) away, said Dr Dobelle. The device provides 'tunnel
vision', with the field of view being equivalent to a card 20 cm tall by five
centimetres wide (eight by two inches) held at arm's length.
Despite this, Dr Dobelle said that Jerry had been able to navigate in
unfamiliar environments including the New York City subway system. He added
that by replacing the camera with a special electronic interface, Jerry was
also learning to use a computer.
The computer software detects the edges of objects
Jerry, along with another volunteer, had the electrodes implanted in his
brain in 1978. Since then the computer used has shrunk in size and the
software improved.
One aspect of future development will focus on how best to provide depth
perception - during the demonstration Jerry had to walk cautiously as he
approached the mannequin and the wall, holding out an arm to prevent
collisions.
Dr Dobelle said a version of the device should go on sale outside the US
later this year.
The first useful artificial eye is now helping a blind man walk safely around
and read large letters, researchers said on Monday.
The 62-year-old man, identified only as Jerry, demonstrated that he was able
to collect a black hat off a white wall, then locate a mannequin and place
the hat on its head.
The specks inside the box are what Jerry sees
Jerry, blinded by an accident at the age of 36, does not see an image but up
to 100 specks of light that appear and disappear as his field of vision
shifts. The specks show up the edges of objects. The constellation of dots,
called phosphenes, has been likened to stars that glitter and fade behind
passing clouds.
"He can do remarkably well," said William Dobelle, chairman of the Dobelle
Institute, the US medical device company that has developed the system.
Richard Normann, an artificial vision expert at the University of Utah,
stressed that the device is "a very limited navigational aid, and a far cry
from the visual experience that normal people enjoy".
However he added that the work suggests that even limited signals to the
brain will let blind people do relatively complicated visual tasks.
'Major step forward'
Dr Bill Heetderks, director of a US National Institutes of Health program to
develop electronic implants that work with the brain, believes an implant
that helps blind people navigate would be a major step forward.
"When Dr Dobelle provides additional details on his methodology that
establishes this result, we may be there," Dr Heetderks said. The device and
its performance are described in the January/February issue of the American
Society of Artificial Internal Organs Journal.
The artificial vision system works by taking an image from a miniature
television camera and distance information from an ultrasound sensor, each of
which is mounted on one lens of a pair of sunglasses.
These signals are processed by a five-kilogram (10 pounds) portable computer
and then a new signal is sent to 68 platinum electrodes implanted in the
person's brain. The electrodes are on the surface of the brain's visual
cortex and stimulate the person to 'see' the phosphenes.
Jerry has recognised five-centimetre-tall (two inches) letters from 1.5
metres (five feet) away, said Dr Dobelle. The device provides 'tunnel
vision', with the field of view being equivalent to a card 20 cm tall by five
centimetres wide (eight by two inches) held at arm's length.
Despite this, Dr Dobelle said that Jerry had been able to navigate in
unfamiliar environments including the New York City subway system. He added
that by replacing the camera with a special electronic interface, Jerry was
also learning to use a computer.
The computer software detects the edges of objects
Jerry, along with another volunteer, had the electrodes implanted in his
brain in 1978. Since then the computer used has shrunk in size and the
software improved.
One aspect of future development will focus on how best to provide depth
perception - during the demonstration Jerry had to walk cautiously as he
approached the mannequin and the wall, holding out an arm to prevent
collisions.
Dr Dobelle said a version of the device should go on sale outside the US
later this year.
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