Non-Invasive BCI
1929
Hans Berger – Discovered the EEG
Electroencephalograph –
Signal Reflecting the electrical field produced by trillions
of individual synaptic connections in the cortex and
subcortical structures of the brain
EEG
EEG
EEG
Niels Birbaumer –
Trained severely paralyzed people to self-regulate the slow
cortical potentials in their EEG in such a way that these
signals could be used as a binary signal to control a
computer cursor (1990s)
Tests included writing characters with the cursor
System users require training just as any person is trained
to use a keyboard or a computer
Those who depend
ALS
Amyotrophic Lateral sclerosis –
Muscle weakness and atrophy throughout the body caused
by the degeneration of upper and lower motor neurons.
Individuals may ultimately lose ability to initiate and
control all voluntary movement
For the most part, cognitive function is preserved
Sensory nerves and the autonomic nervous system are
generally unaffected
ALS
BCI systems have the ability to allow a paralyzed,
“locked-in” patient to communicate words, letters and
simple commands to a computer interface that
recognizes different outputs of EEG signals and
translates them through use of assigned algorithms into
a specific function or computing output that the user
has the ability to control.
A complex mechanical BCI system would allow a user to
control an external system possibly an artificial limb by
creating an output of specific EEG frequency
P300 Speller
User observes 6x6 matrix where each cell contains a
character or symbol
User receives stimuli that coordinate with a specific
output
User learns to recognize certain stimuli that exist in
relation to a specific output
System created successful feedback when tested among
the ALS population
EEG Rhythms
For analyzing EEG signals, studies suggest that
frequencies of 8-12 Hz (mu) and 13-28 Hz (Beta) are
most sensible for human control
The form or magnitude of a voltage change evoked by a
stereotyped stimulus is known as an evoked potential
and can serve as a command
ie. The amplitude of the EEG in a particular frequency
band, can be used to control movement of a cursor on a
computer screen
Non-Invasive BCI
Forefront of human experimentation
Cost effective
No implantation
Susceptible to noise
Cranial barrier dampens signal
What about right now
Today, BCIs are already being incorporated into modern
technologically dependent society
As they were once thought to be strictly
a bridge between a neurologically
disconnected brain to an outside mechanism
of replacing neuromuscular function,
the commercial exploitations have already
begun as devices can now be purchased that
allow users to control an exterior system
and navigate and control a graphical
Interface using only EEG output signals
NeuroSky
Developers at NeuroSky created the Brainwave, a
comprehensive non-invasive BCI that connects the user
to iOS and Android platforms, and transfers all signal
information through Bluetooth as opposed to radio.
The EEG outputs for this setup are controlled primarily
by variations in brain-state. In order to achieve a
specific level of EEG the user may be prompted to relax
or improve focus, thus altering the specific output of
brain energy and ultimately changing the level of
expressed EEG signals
Emotiv
Devolped a BCI called the EPOC
16 sensors capture EEGs to the extent of which the
system can return feedback to let the user know
whether or not they blinked, or sneezed, or smiled
The device allows a user to connect to a computer, and
perform all basic functions that they otherwise would
control using a keyboard, but with the mind. That
includes control of gaming platforms as well
Future
For the future, BCI technology seems very applicable in
a wide variety of areas whether it be medically or
commercially
The possibilities of how far the systems can go is
virtually limitless
Control of subvocalization and more advanced EEG
processing could lead to telepathic communication and
active learning mechanisms
This all would bring up an unfeasible amount of ethical
discomfort and confrontation
Bibliography
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Wikipedia: Biomedical Engineering <en.wikipedia.org/wiki/ Biomedical_engineering>.
"Disruptions: Brain Computer Interfaces Inch Closer to Mainstream." Bits Disruptions Brain Computer Interfaces Inch Closer to Mainstream
Comments. N.p., n.d. Web. 23 Sept. 2013."Brain–computer Interface." Wikipedia. Wikimedia Foundation, 21 Sept. 2013. Web. 23 Sept.
2013.
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Schalk, S., McFarland , D., Hinterberger, T., Birbaumer, N., & Wolpaw , J. (2004 ). Bci2000: A general-purpose brain-computer interface
(bci) system . IEEE Transactions on Biomedical Engineering , 51(6), 1034-1043. Retrieved from http://bpv-tese.googlecode.com/hghistory/095dce5394352001ef2ddaefe6f10678ca6413d5/src/referencias/10.1.1.115.7600.pdf
Heetderks , W., McFarland , D., Hinterberger, T., Birbaumer, N., Wolpaw , J., Peckham, P., Donchin, E., & Quatrano, L. (2000). Braincomputer interface technology: A review of the first international meeting . IEEE Transactions on Rehabilitation Engineering , 8(2), 164173. Retrieved from http://www.ocf.berkeley.edu/~anandk/neuro/BCI Overview.pdf
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