25-01-2013, 03:57 PM
Brain-Computer Interfaces:Where Human and Machine Meet
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BCI BACKGROUNDER
BCI research includes disciplines
such as nanotechnology, biotechnology,
information technology, cognitive
science, computer science,
biomedical engineering, neuroscience,
and applied mathematics.
History
Scientists have been actively
researching BCI since the early
1970s. At that time, Jacques Vidal,
now a University of California, Los
Angeles, emeritus professor, led the
university’s federally sponsored
Brain-Computer Interface Project.
Over time, researchers have experimented
with implanting simple BCI
sensors within rats, mice, monkeys,
and humans.
In the late 1990s, researchers at the
Georgia Institute of Technology and
Emory University demonstrated BCI’s
medical potential by implanting an
electrode in the motor cortex of a
patient who was paralyzed below the
neck and unable to speak. The technique
let the patient communicate by
moving a computer cursor.
In 1999, scientists at the MCP
Hahnemann School of Medicine and
Duke University Medical Center
trained rats to use their brain signals
to move a robotic water-dispensing
arm.
Invasive versus
noninvasive approaches
There are two principal BCI
approaches: invasive techniques,
which implant electrodes directly
onto a patient’s brain; and noninvasive
techniques, in which medical
scanning devices or sensors
mounted on caps or headbands read
brain signals.
Both approaches have drawbacks,
according to University of Southern
California professor Theodore Berger,
chair of the World Technology
Evaluation Center’s Panel on Brain
Computer Interfaces.
Noninvasive approaches are less
intrusive but can also read brain signals
less effectively because the electrodes
cannot be located directly on
the desired part of the brain. Invasive
techniques, however, require surgery
and carry the risk of infection or
brain damage.
Moreover, noninvasive approaches’
ability to read signals from many
points in the brain could help identify
a wider range of brain activity. This
would be helpful because the cells that
address the multiple types of motions
and movement of various body parts
are in different parts of the brain,
noted Berger.
However, he added, processing the
large amount of data that neurons
in multiple parts of the brain would
Brain-Computer
Interfaces:Where
Human and
Machine Meet
Sixto Ortiz Jr.
Eventually, Cyberkinetics hopes to
augment the system to wirelessly
send brain signals to amplifiers and
then a computer, which would eliminate
the need for connectors and
cables, said company president and
CEO Timothy Surgenor.
Wadsworth Center:
A noninvasive approach
The New York State Public Health
Department’s Wadsworth Center, a
public health laboratory, is using a
noninvasive electroencephalogram
(EEG) cap to acquire brain signals
by recording neuronal electrical
activity.
The research team—led by
Jonathan Wolpaw, chief of Wadsworth’s
Laboratory of Nervous
System Disorders and a University of
Albany professor—has developed
the BCI2000 research system.
The BCI2000 uses an EEG cap,
which includes up to 200 electrodes
that are placed on the scalp along
with conductive paste to aid in the
capture of electrical signals emitted
by neurons in the brain.
The system uses a 16-channel
biosignal amplifier to boost the captured
signals. Its DSPs then extract
and measure signal features, which
a digitizer prepares for computer
processing.