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Dec. 29, 2004 –
University of Utah researchers have won about $6.7 million in federal
grants to develop wireless electrodes that would be implanted to
provide blind people with artificial vision and stimulate paralyzed
body parts and so disabled people could walk, talk or control a
computer with their thoughts.
“We plan to spend this $6.7 million to further develop technology
that we hope will someday help blind individuals see, allow paraplegics
to stand and eventually walk, and let people with vocal cord problems
speak,” says Richard Normann, a professor of bioengineering
and ophthalmology who is helping spearhead the project.
The money is in the form of four grants from the National Institutes
of Health to scientists at the university’s College of Engineering
and University of Utah Health Sciences Center. The projects receiving
the funding are intended to expand the Utah Electrode Array technology
that Normann first developed in 1989.
The Utah Electrode Array is a silicon chip measuring a quarter-inch
on each side and containing 100 tiny electrodes in a 10-by-10 grid.
The array is implanted under the dura, which is the membrane covering
the brain.
Normann pursued commercial development of the Utah Electrode Array
by forming a spin-off company name Bionic Technologies, LLC, which
he and co-owner Brian Hatt sold to Cyberkinetics Neurotechnology
Systems, Inc. in 2002. Cyberkinetics incorporated the array and
other technologies into its BrainGate System, and implanted a Utah
Electrode Array into a paralyzed human patient for the first time
in June 2004. The electrodes, which poke into the part of the brain
controlling movement, allowed the patient to control a computer
screen cursor by thinking about moving the cursor.
Now, “we are trying to make the system even better”
by developing a “smart” wireless electrode array so
it won’t be necessary for people using the device to have
100 wires emerging from their skull, something that raises the possibility
of infection and also of getting the wires snagged while the person
is using a wheelchair, Normann says.
“To go from a bundle of wires sticking out of somebody’s
head to a totally implantable system that is invisible will be a
major advance in this technology,” he adds.
Normann has spent more than a decade developing the Utah Electrode
Array so it eventually can be implanted in the brains of blind people.
They would wear a tiny eyeglass-mounted camera to collect visual
information, and then relay it to electrodes in the brain's visual
cortex. The wireless array would make such an artificial vision
system easier for blind people to wear and use.
Here are details of the four grants, which total as much as $6.658
million:
-- The largest grant is for $2.816 million for four years to Florian
Solzbacher and Reid Harrison – both assistant professors of
electrical and computer engineering – along with Normann.
They will develop a wireless version of Utah Electrode Array, which
will look much like the original but will be slightly larger and
“will have electronic circuitry integrated into it to amplify
the signals from each of the 100 electrodes, do signal processing
on those signals [to filter out noise and other unimportant information]
and send those signals wirelessly to a receiver located outside
of the body,” Normann says.
-- A four-year grant of $2.048 million was requested by Normann;
Gregory Clark, an associate professor of bioengineering; Nicholas
Brown, a research assistant professor in orthopedic surgery and
James Martin, an assistant professor of exercise and sport science.
Normann received verbal confirmation the grant was approved, but
says the final amount may be somewhat smaller than what was requested.
The researchers will use a version of the electrode array that has
electrodes of varying lengths, from 0.5 to 1.5 millimeters, so that
when it is implanted on nerves that control the legs or arms, it
will come into contact with multiple nerve fibers within a nerve
and not just those at a single depth within the nerve.
“This opens up a whole bunch of new applications, one of which
is to implant these electrodes in the peripheral nerves of the legs
of a paraplegic,” says Normann. “We believe that if
we implant three Utah Electrodes Arrays into three different nerves
in each leg – a total of six electrode arrays – and
stimulate them appropriately, we should be able to help the paraplegic
to get out of the wheelchair, stand up and eventually walk using
his or her muscles,” although that won’t be tried until
after pre-clinical feasibility studies.
Another use would be to implant the array in nerves that control
the bladder, with the array run by a switch. This could allow a
paraplegic to regain control of urination.
-- A $1.383 million grant for four years was awarded to bioengineering
Professor Patrick Tresco and Normann to make new Utah Electrode
Arrays even more biocompatible than they already are.
So far, nonfunctioning arrays have been implanted in nine temporal
lobe epilepsy patients before they underwent unrelated brain surgery
for their disorder. The tests found no problems. The arrays have
been implanted in animals for up to three years. Nevertheless, the
body’s immune system tends to “wall off” any foreign
material implanted in the brain, so Tresco and Normann will develop
new coatings for the array “so the brain is even more unaware
of the fact it has been implanted,” Normann says.
-- The final grant, for $411,000 over two years, was awarded to
Marshall Smith – an associate professor of otolaryngology/head
and neck surgery – and to Normann.
Smith says the project will determine the feasibility of using a
Utah Electrode Array to restore the ability to speak in certain
people by stimulating nerves that control the vocal folds (also
known as vocal cords), which are the voice-producing folds of tissue
in the voice box or larynx.
The vocal folds open when we breathe and close when we speak. Some
people lose their voice when a vocal fold is paralyzed by stroke;
trauma; damage during surgery of the neck, thyroid or chest; or
a tumor that impinges on the nerve to the vocal fold.
“This device is going to be used in an attempt to reanimate
the vocal folds to restore the normal movement, both the opening
and closing movement of the vocal folds,” Smith says.
The existing Utah Electrode Array will be used in initial tests,
but Smith says he hopes a wireless version ultimately will be available
to help restore speech.
Scientists at the New York State Department of Health recently gained
publicity for a noninvasive method of allowing paralyzed people
to control computers or other devices by reading brain signals using
64 electrodes in a cap placed on the scalp. Its major advantage
is that nothing needs to be surgically implanted.
But Normann says the method has a big disadvantage, namely, that
signals from nerve cells in the brain are weak and “smeared”
together by the fact that the skull and scalp jumble the signals,
meaning a paralyzed person using the device could control a computer
or other device only very slowly and with considerable training.
Implanted electrodes can more precisely “listen” to
individual nerve cells and record their activity, allowing paralyzed
people to control computers or their own limbs much more quickly,
Normann says.
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| Media Contacts: |
| Richard Normann, professor of bioengineering
and ophthalmology |
office (801) 581-7645, cellular (801)
673-5589, normann@utah.edu |
| Lee Siegel, science news specialist, University of
Utah Public Relations |
office (801) 581-8993, cellular (801) 244-5399, leesiegel@ucomm.utah.edu |
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