Imagine a chip, strategically placed in the brain,
that could prevent epileptic seizures or allow someone
who has lost a limb to control an artificial arm just
by thinking about it.
It may sound like science fiction, but University
of Florida researchers are developing devices that can
interpret signals in the brain and stimulate neurons
to perform correctly, advances that might someday make
it possible for a tiny computer to fix diseases or
even allow a paralyzed person to control a prosthetic
device with his thoughts.
Armed with a $2.5 million grant they received this
year from the National Institutes of Health, UF
researchers from the College of Medicine, the College
of Engineering and the McKnight Brain Institute have
teamed up to create a “neuroprosthetic” chip designed
to be implanted in the brain. They are currently
studying the concept in rats but are aiming to develop
a prototype of the device within the next four years
that could be tested in people.
The initial goal? To correct conditions such as
paralysis or epilepsy.
“We really feel like if we can do this, we’ll have
the technology to offer new options for patients,”
said Justin Sanchez, director of the UF
Neuroprosthetics Research Group and an assistant
professor of pediatric neurology, neuroscience and
biomedical engineering. “There’s kind of a revolution
going on right now in the neurosciences and biomedical
engineering. People are trying to take engineering
approaches for directly interfacing with the brain.
“The hope is we can cure more immediately a variety
of diseases.”
Researchers have been able to decode brain activity
for years using electroencephalography. Referred to
commonly as an EEG, this technology involves placing a
sensor-wired net over the head to measure brain
activity through the scalp. But the technology wasn’t
quite sensitive enough to allow researchers to decode
brain signals as precisely as needed, Sanchez said.
Now researchers are focusing on decoding signals from
electrodes placed directly into the brain tissue using
wires the width of a strand of hair.
“(Scientists have) realized that by going inside
the brain we can capture so much more information, we
can have much more resolution,” Sanchez said.
The chip UF researchers are seeking to develop
would be implanted directly into the brain tissue,
where it could gather data from signals, decode them
and stimulate the brain in a self-contained package
without wires. In the interim, UF researchers are
studying implantable devices in rats and are
evaluating an intermediate form of the technology —
placing electrodes on the surface of the brain — in
people.
UF researchers have developed new techniques using
surface electrodes to access signals almost as
precisely as they could with sensors implanted in the
brain, according to findings the researchers published
in May in the Journal of Neuroscience Methods.
Developing these techniques is a big step forward in
understanding how to best decode a patient’s intent
from their brain waves and should have broad
implications for delivering therapy, Sanchez said.
To gather data about the brain’s sophisticated
cues, which vary from person to person, Sanchez
studies the brain signals of children with epilepsy
who are scheduled to undergo surgery to remove the
part of the brain that is causing seizures. These
patients often must be monitored for several days to
weeks with electrodes placed directly on the brain.
Doctors use this to pinpoint the problem area when a
child has another seizure.
Because the children already have electrodes in
place, Sanchez is able to use the data gathered from
them to understand more about the brain’s signals in
general.
UF researchers are also working on intermediate
concepts that could be wearable, like a diabetes pump,
Sanchez said.
“We have intermediate designs that connect to the
brain, interpret signals and can wirelessly send
commands to devices,” he said. “This is another path
of technology we’re pursuing.”
To create these technologies, Sanchez is in the
process of developing a center for brain-machine
interfaces at UF with faculty from the College of
Engineering, including Jose C. Principe; John G.
Harris; Toshikazu Nishida; and Rowan Bashirullah.
But several challenges face researchers in bringing
these technologies to patients, said Dr. Steven J.
Schiff, a professor of engineering and neuroscience at
The Pennsylvania State University and director of the
Penn State Center for Neural Engineering.
For patients with epilepsy, who often have to take
several medications or undergo surgery for relief from
debilitating seizures, a neuroprosthetic device could
be the best form of treatment, Schiff said, adding
that more work needs to be done to understand the
mechanics of what causes diseases such as epilepsy and
Parkinson’s.
“The challenge is not so much the technology,”
Schiff said. “The challenge is to use that technology
wisely.”
The day may not be too far off when patients can
control a prosthetic hand or leg just by thinking
about it, Sanchez said.
“It’s becoming a reality,” Sanchez said. “We’re
designing electronics that we can interface with
biological systems and we can use that to help
people.”
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Source:
University of Florida
Published on 26th
July 2007
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