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Harnessing Brain Power
Georgia Tech research assists direct By Gary Goettling |
F-I-V-E.
At the Veteran's Administration Hospital in Decatur, Ga.,
53-year-old Johnny Ray focuses his thoughts to move a cursor across
a keyboard displayed on a computer screen near his bed. Slowly
and deliberately he selects the letters to correctly answer the
question: How many children do you have?
A device developed at Georgia Tech is helping Ray, the victim
of a massive stroke that left him mute and almost completely
paralyzed, communicate through a computer using the tiny
electrical impulses generated by his brain.
Dr. Philip R. Kennedy, a clinical assistant professor of
neurology at Emory University
in Atlanta, developed and patented
the "neurotrophic electrode" in the mid-1980s while working as a
neural prosthetics researcher at Tech. His work capitalizes on
the basic fact that the act of thinking prompts physical activity
in the brain in the form of electrical impulses. Implanted into a
patient's brain, the electrode detects and captures those
electrical signals, which are processed by customized
microelectronics and software applications to move a cursor and
select icons on the screen. In effect, the brain's neural signals
become a computer mouse.
A Carrollton, Ga., drywall contractor, Ray received the
implant in the spring of 1998. By the end of the year he learned
to select icons representing phrases such as "I am too cold."
After a few more months of practice, he mastered the keyboard and
began forming his own words — even holding short conversations
with his doctors.
"It works, and I knew it would work," says Kennedy of the
neural implant. "Fourteen months after implantation we're still
getting strong signals, and that's incredible — very hopeful."
Years of Research
"It basically began at Tech and it's very much a Tech project,
but everyone's essential," says Kennedy, a naturalized U.S.
citizen originally from County Limerick, Ireland. "I call the
project a child of the Atlanta Village — we've got people from
Georgia State, as well as from Tech and Emory working on it. It's
a big, combined effort."
Kennedy earned a medical degree at the National University of
Ireland and trained as a surgeon in Dublin. In 1976 he immigrated
to Canada to study neurosurgery, then moved to Chicago and earned
a Ph.D. at Northwestern University studying neurophysiology and
neuroanatomy. Kennedy joined Georgia Tech in 1986 as a research
scientist, when he also started developing his neurotrophic
electrode. From 1990 to 1997, he served as director of Tech's
Neuroscience Laboratory. For the past two years Kennedy has
divided his time among a private neurology practice and his
research, the latter facilitated by an affiliation with Emory's
School of Medicine.
The key component of Kennedy's cortical control device is the
hollow glass, cone-shaped neurotrophic electrode. About the size
of a ballpoint pen tip, the device contains a pair of microscopic
gold wires and is coated with a biocompatible substance. That
coating encourages neurites — tentacle-like structures extending
from neurons — to migrate into the electrode, thereby ensuring a
solid electrical connection and also holding the device firmly in
place. In fact, the ability to remain stationary distinguishes
Kennedy's electrode from similar efforts. It's a critical
attribute if a patient is to achieve control with consistent
results.
The low-amplitude signals traveling across the local neurons
pass through the electrode, which relays the impulses to a tiny
power induction amplifier and FM transmitter inserted just under
the scalp. Those signals, amplified about 1,000 times, are
broadcast to a computer where signal-recognition software
translates them into cursor movement.
Two electrodes are employed because basic computer operation
is a two-step process. The first requires moving a cursor among a
number of options; the second involves selecting one of those
options.
If the electrode is implanted in the motor cortex in an area
associated with, say, finger movement, the patient can generate
electrical signals to move the cursor by concentrating on moving
a finger. Another electrode, implanted in an area associated with
a different kind of movement, can facilitate the computer's
"select" function.
Because the location of movement-specific cells varies from
person to person, a magnetic resonance imaging scan performed
before implantation helps identify the best location for the
electrodes.
"It's actually not very high-tech," Kennedy says. "One thing
that has made it possible is that small computers can do so much.
It's amazing what they can do."
Human Trials
Kennedy and his co-researchers must be very selective for the
human trials.
"This will not help people in a coma," Kennedy explains.
"People have to be cognitively intact and know what's going on,
but be unable to communicate." The best candidates at this stage
of the experiment are individuals with ALS or those with high
brain stem or high spinal cord injuries, or patients with
advanced degenerative muscle disease, he says.
The latest patient has been bedridden for the past four years
and in a severely weakened state for the past 10. The metabolic
muscle disease afflicting T.T. has left him with only slight eye
movement left and right, and slight head movement, Kennedy says.
"His brain is not affected," Kennedy adds, "and that makes him
a good candidate for the procedure."
Human/Computer Interaction
The collaborative, multidisciplinary effort's short-term goal
is to devise new and more efficient means of human-computer
interaction, thereby opening a communications window to the
outside world for severely paralyzed individuals. Eventually the
technology could enable many other interactive functions as well.
For victims of paralysis, the ability to manipulate a computer
holds implications far greater than the simple ability to
communicate wants and needs, Kennedy says.
"You can run businesses off the Internet," he says. "So why
couldn't these people do that? All they have to do is run the
computer. The technology opens up that possibility."
Kennedy is also convinced that his neurotrophic electrode
portends many possibilities of its own, including operating
complex robotic prosthetics or muscle stimulators.
Easier Communication
Now an assistant professor in the Computer Information Systems
Department at Georgia State University,
Moore also teaches
software engineering to Tech students and involves them in her
part of the research.
"My students wrote a communications program that allows him to
choose an icon that stands for critical phrases like, ‘I'm too
cold' or ‘I need the nurse,' " Moore says. "By selecting one
button, he can communicate a whole phrase instead of having to
spell everything out."
As Ray's proficiency has increased, so has the sophistication
of the communication, Moore says.
"We're actually having conversations with him," she explains.
"Instead of asking him to spell Phil or Mel, we're asking things
like, ‘What's the best book you've read? What's your favorite
movie?' He moves the cursor around and selects the letters to go
into a writing program, and then he's able to speak them because
we added a voice synthesizer.
"He's definitely improving. It's such a thrill for all of us,
and it has improved his motivation, too."
Ray may soon begin navigating the Web with a browser built for
him by Moore and her students. The group is also perfecting a
virtual "dart game" to help future patients learn to control the
cursor, and analysis software to track the learning curves of
patients.
"We're trying everything we can think of," Moore says.
"Nobody's ever done this before — this is a totally new area.
It's definitely cutting-edge, very futuristic technology, but the
neatest thing about it is that it works."
Ray's recent progress is all the more gratifying because it
follows a long period of health troubles.
"Anybody with a complete paralysis has health problems, but
they are exacerbated by things like skin problems, bed sores and
infections," Moore explains. "Sometimes it's hard to work with
him because he's on so many painkillers, the brain signals don't
happen. But lately he's been feeling better, he's off the
ventilator, and he is really doing well."
Collaborative Effort
Andy Hopper and Barry Sudduth, research engineers at the
Biomedical Interactive Technology Center, built the electronics
that interface with the electrode.
"We have recently changed the design of the electronics from
surface-mount components that were soldered to each other to a
more robust PC board-based design using surface-mount
components," Hopper says.
At the Georgia Tech Center for Rehabilitation Technology,
graduate student Kim Adams and research scientist John
Goldthwaite have provided valuable, though unofficial,
assistance.
"We're trying to help with the rehab engineering part —
technical equipment, assisted technology, recommending software
and things like that," Goldthwaite says, adding that he hopes the
center can take a more active role in the future.
"We're trying to stay in it, but we don't have the funding to
participate as much as we'd like to," he explains. "At some
point, we would like to work with the patients and help them use
computer-based augmented communications."
Also, Dr. Steven Sharpe and Neal Hollenbeck of the Georgia
Tech Research Institute were deeply involved in the early work to
develop a telemetry device for transmitting brain signals to a
receiver.
Now, a research team including Emory University professor Dr.
Roy A.E. Bakay is leading the way in implanting cone electrodes
in human trial patients.
Determined and Dedicated
The National Institutes of Health provided a grant for his
first three human trials, but that support does not extend beyond
T.T.'s implantation.
Various grant proposals are in the hopper, and while there's
nothing concrete to report yet, Kennedy remains determined.
"I'm never going to give up."
For more information, contact Dr. Philip Kennedy at his private practice office at 770-622-2230. Or, you may contact him at Emory University at 404-727-3818.
Photo by Gary Meek
Dr. Philip R. Kennedy, a clinical assistant professor of
neurology at Emory University in Atlanta, developed a device that
helps disabled patients communicate through a computer.
The success with Johnny Ray follows 13 years of research,
testing and animal trials for the electrode and other components
of the system collectively called a "cortical control device."
Kennedy received U.S. Food and Drug Administration approval to
conduct human trials and an enabling grant from the National
Institutes of Health.
Photo by Gary Meek
Dr. Kennedy
patented the "neurotrophic electrode" in the mid-1980s while
working as a neural prosthetics researcher at Tech.
Ray is the second person to receive the electrode. The first
patient, a woman in the final stages of amyotrophic lateral
sclerosis (ALS) — also known as Lou Gehrig's disease — died
from the disease 77 days after surgery and before she could
master the computer-control technique. A third patient
identified only by his initials, T.T., has been selected for
implantation.
While computers have been helping paralysis victims for years
through various kinds of adaptive interfaces, Kennedy's project
is the first to establish a direct connection between the brain
and a computer.
Exploring possibilities for the cortical control technology is
the job of Dr. Melody Moore, a former graduate student and
faculty member at Georgia Tech's College of Computing.
Photo by Gary Meek
Former Georgia Tech computing professor Dr. Melody Moore, now
at Georgia State University, led her students in writing a
communications program that allows patients to choose an icon
that stands for critical phrases like, "I'm too cold" or "I need
the nurse."
In addition to Moore and Kennedy, the cortical control device
owes its success to the work of many other Tech scientists.
But even with all its promise, Kennedy's research has been
beset with frustrating funding problems throughout its history.
At one point several years ago, when Kennedy was making the
transition from basic research to application of his electrode,
there were fears the work may have to be put on hold for lack of
money. With typical determination, he decided to raise research
money by obtaining dollar pledges for each mile he ran in the
Atlanta Track Club's Thanksgiving Day Marathon. The Georgia Tech
Research Corporation matched the pledges.
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