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Welcome Fellow Ocularists
This section contains a selection of Coming Events, Articles,
News Items, Tips & Techniques, and Links to Articles
and Information that should be of interest to our fellow
Ocularists.
Coming Events
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Schedule and registration form (printer-friendy copy)
are online at the ASO
Site.
Your tips and techniques for better ocular prostheses are
welcome. We would like to use this forum as an informal
place for exchanging prosthetic techniques between peers.
If you come across any ocular prosthetic news and articles,
please inform us and
we will include them in our reference (with proper credit).
Articles of interest to the Ocularist
News Items
- Tuesday January 18, 2000:
Artificial Vision System for The Blind Announced by The
Dobelle Institute
-- Device Stimulating Visual Cortex of Brain Promises
Independence for the Totally Blind --
- New York, NY - A biomedical engineering team today
announced development of an artificial vision system providing
independent mobility to blind people. The system,
reflecting more than 30 years in development work by the
Dobelle Institute in New York City and its affiliates
on Long Island and in Switzerland, enables a totally blind
person to achieve visual acuity of about 20/400, in a
narrow visual "tunnel."
The "Dobelle Eye," as described
in the ASAIO
Journal (the journal of American Society of Artificial
Internal Organs) consists of a sub-miniature television
camera and an ultrasonic distance sensor, both of which
are mounted on a pair of eyeglasses. The sensors
connect through a cable to a miniature computer, which
is worn in a pack on a person's belt. After processing
the video and distance signals, the computer uses sophisticated
computer-imaging technology, including edge-detection
algorithms to simplify the image eliminating "noise."
The computer then triggers a second microcomputer that
transmits pulses to an array of 68 platinum electrodes
implanted on the surface of the brain's visual cortex.
Bringing wires through the skin for two decades without
discomfort or infection is one of many independent inventions
that has made the new visual prosthesis possible.
When stimulated, each electrode produces one to four closely
spaced phosphenes, which have been described as resembling
"stars in the sky." This white phosphene on a black
background "map" is roughly eight inches by two inches
at arms length.
The patient in the study reported in ASAIO Journal is
a 62-year-old male who was totally blinded by trauma when
he was 36 years old. After learning to use the system
and "read" the display, the patient is now able to read
two inch tall letters at a distance of five feet, representing
a visual acuity of about 20/400. Although the relatively
small electrode array produces tunnel vision, the patient
is also able to navigate in unfamiliar environments including
the New York City subway system. By replacing the
sub-miniature television camera with a special electronic
interface, the patient is also learning to "watch" television,
use a computer, and gain access to the Internet.
The computer package employed in the initial system was
the size of a large bookcase and weighed several thousand
pounds. After six generations of improvement over
the last 21 years, the external electronics package has
now been miniaturized so it is about the size of a dictionary
and weighs approximately ten pounds, including batteries.
Dr. Dobelle's first human experiments in this artificial
vision project took place beginning in 1970 and involved
cortical stimulation of 37 sighted volunteers undergoing
surgery on the occipital lobe under local anesthesia to
remove tumors and other lesions. Three blind volunteers
were then temporarily implanted with electrode arrays
to stimulate the visual cortex. Subsequent experiments
involved four blind volunteers who were implanted with
permanent electrode arrays employing percutaneous connecting
pedestals. The Dobelle system's electrodes and connecting
pedestal were surgically implanted in two blind volunteer's
brains in 1978 at the Columbia-Presbyterian Medical Center
in New York City. Both have retained their implants
and one is the subject of the study reported in the ASAIO
Journal.
Dr. Dobelle said that the new artificial vision systems
are expected to be made available, on a limited commercial
basis, starting later this year.
The Dobelle Institute and its affiliates constitute one
of the world's most sophisticated organizations for education,
research, development, manufacturing and clinical implementation
of medical devices. Over the last 30 years, the
Dobelle Institute has been responsible for the design,
manufacture and distribution of other neurological "pacemakers"
to control breathing, intractable pain and the urogenital
system of about 15,000 patients in more than 40 countries.
These clinical systems have gained full regulatory and
reimbursement approval from the FDA, Medicare and analogous
foreign agencies.
- Related Article:
- The
First Artificial Vision Systems in Commercial Distribution
By Wm. Dobelle, Joao Lobo Antunes,
Domingos Coiteiro, John Girvin
Other News Items
- Wednesday August 9, 2000:
Canadian Researchers to
Commercialize a Robotic Eye
By Julie Remy
Tips & Techniques
 Directory
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