2. CONTENTS:
What is Brain-Computer Interface?
Principle behind BCI
Objective of BCI
Types of BCIs
History
Implementation
Software behind BCI
Applications
Limitations
Future Concerns
Conclusion
References
Brain-Computer Interface 2
3. What is Brain-Computer
Interface?
Brain Computer Interface is a direct technological
interface between a brain & a computer system not
requires a motor output from the user.
It is abbreviated as BCI.
It is also known as Direct Neural Interface (DNI) &
Brain – Machine Interface (BMI).
Brain-Computer Interface 3
4. Continued
Brain-computer interface is an
electrode chip which can be
implemented in the brain through
surgical procedure.
• When it is implemented in brain
the electrical signal exchanged by
neurons within the brain are sent to the
computer and then the computer is
controlled by person.
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5. Principle Behind BCI
This technology is based on to sense, transmit, analyze
and apply the language of neurons.
It consist of a sensor that is implanted in the motor cortex of
the
brain and a device that analyses brain signals. The signals
generated by brain are interpreted and translated into cursor
movement on computer screen to control the computer.
It consists of a silicon array about the size of an Aspirin tablet
that contains about 100 electrodes each thinner than a human
hair.
Brain-Computer Interface 5
7. KEY ISSUES IN BCI RESEARCH AND
USERS
Target users:
Researchers - clinical researchers, neuroscientists,
signal processing experts, etc.
Technical operators - caregivers, therapists who are in
charge of training someone on BCI operation.
End-users -people with disabilities who rely on the
system for communication
Casual end-users -those who use a BCI as an alternative
input for entertainment devices.
9. Structure of a BCI
1) Signal Acquisition: the EEG signals are obtained from
the brain through invasive or non-invasive methods (for
example, electrodes). After, the signal is amplified and
sampled.
2) Signal Pre-Processing: once the signals are acquired, it is
necessary to clean them.
3) Signal Classification: once the signals are cleaned, they
will be processed and classified to find out which kind of
mental task the subject is performing.
4) Computer Interaction: once the signals are classified,
they will be used by an appropriate algorithm for the
development of a certain application.
12. BCI vs Neuroprosthetics
Neuroprosthetics typically connect the nervous
system to a device, whereas BCIs usually connect the
nervous system with a computer system.
Practical neuroprosthetics can be linked to any part
of the nervous system—for example, peripheral
nerves
While the term "BCI" usually designates a narrower
class of systems which interface with the central
nervous system.Brain-Computer Interface 12
13. Objective of BCI:
The goal of the Brain-Computer Interface is to
develop a fast and reliable connection between the
brain of a severely disabled person and a personal
computer .
The ‘Brain Gate’ device can provide paralysed or
motor-impaired patients a mode of communication
through the translation of thought into direct
computer control.
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14. Types of BCIs:
• Invasive BCI
Invasive BCIs are implanted directly into the grey matter of
the brain during neurosurgery.
• Non Invasive BCI
Non-Invasive BCIs do not involve neurosurgery. They are
just like wearable virtual reality devices.
• Partially Invasive BCI
Partially invasive BCI devices are implanted inside the skull
but rest outside the brain rather than within the grey matter.
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15. History- Discovering the Basics
1924: Hans Berger discovers the EEG
Analyses the interrelation of EEG and brain
diseases.
1970: First developments to use brain waves as input
ARPA has vision of enhanced human
First step in the right direction
16. History of BCI:
• Research on BCIs has been going on for more than 20
years, but from the mid-1990s there has been a
dramatic increase in working experimental implants.
• Brain-Computer Interface was commercially
developed by the bio-tech company Cyberkinetics in
2003 in conjunction with the Department of
Neuroscience at Brown University.
Brain-Computer Interface 16
17. BCI Research On Animals:
At first, rats were implanted
with BCI .
Signals recorded from the
cerebral cortex of rat operate
BCI to carry out the movement.
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18. Contd…
• Researchers at the University
of Pittsburgh had demonstrated
on a monkey that can feed itself
with a robotic arm simply by
using signals from its brain.
Brain-Computer Interface 18
19. Functionality of BCI
Steps for the function of BCI.
1.user wired to a multi-electrode EEG skin cap, which is
connected to a pc running BCI2000.
2.user of the signal asked to generate a series of signals.
3.EEG potential record and analyze the signal
4.the software attempt to match these signal to
previous recorded signals.
5.at last identified words are wrapped on output devices
like-screen or speech synthesizer.
23. BCI On HUMANS
In December 7, 2004, brain-computer interface had been
clinically tested on a human by an American biotech
company Cyberkinetics.
The first participant in these trials was a 25-year-old
man who had sustained a spinal cord injury leading to
paralysis in all four limbs .
Brain-Computer Interface 23
24. Contd…
Over a period of nine months, he
took part in 57 sessions during
which the implanted Brain Gate
sensor recorded activity in his
motor cortex region while he
imagined moving his paralyzed
limbs and then used that imagined
motion for several computer-
based tasks such as, moving a
computer cursor to open e-mail,
draw shapes and play simple video
games.
Brain-Computer Interface 24
25. How BCI Implements?
A more difficult task is interpreting the brain signals for
movement in someone who can't physically move his own arm.
With a task like that, the subject must "train" to use the device.
With an implant in place, the subject would visualize
closing his or her disabled hand. After many trials, the software
can learn to recognize the signals associated with the thought of
hand-closing.
Software connected to a robotic hand is programmed to receive
the "close hand" signal and interpret it to mean that the robotic
hand should close. At that point, when the subject thinks about
closing the hand, the signals are sent and the robotic hand
closes.
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27. Contd…
This could even be accomplished without the
"robotic" part of the device. Signals could be sent to
the appropriate motor control nerves in the hands,
bypassing a damaged section of the spinal cord and
allowing actual movement of the subject's own hands.
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28. Software behind BCI
• The technology is comprised of four main
components; a signal capture system, a
signal processing system, a pattern
recognition system, and a device control
system.
• The signal capture system includes the
electrodes themselves and the isolated
electronic amplifiers
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29. Contd…
The signal processing system includes the
algorithms for the linear prediction of the signal.
The pattern recognition system often used to be
composed of neural networks as to recognize
which neurons are producing these signals.
Interfaces have been developed to control
different devices .
Brain - Computer Interface 29
30. Applications
One of the most exciting areas of BCI research is the
development of devices that can be controlled by
thoughts.
For a quadriplegic, something as basic as controlling a
computer cursor via mental commands would
represent a revolutionary improvement in quality of life.
Some of the applications of this technology are also
frivolous, such as the ability to control a video game by
thought , ability to change TV channels with your mind
etc.
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31. Limitations
At present ,the biggest impediment of BCI technology is
the lack of sensor modality that provides safe, accurate,
and robust access to brain signals.
It is very expensive.
• Information transformation rate is limited to 20 bits/min.
• Difficulty in adaptation and learning.
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32. Future Concerns
Light Reactive Imaging BCI devices are still in the realm
of theory.
This would involve implanting a laser inside the skull.
The laser would be focussed on a single neuron and the
neuron’s reflectance is measured by a separate sensor.
• When the neuron fires, the light pattern and wavelength it
reflects would change slightly . This would allow the
researchers to monitor a single neuron and require less
contact with the tissue.
Researchers of the Carleton University , Canada believe
that the same interface could form the basis of a mind-
controlled password system.
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33. Conclusion
• The results of BCI are spectacular and almost
unbelievable.
• BCI can help paralyzed people to move by controlling their
own electric wheelchairs, to communicate by using e-mail and
Internet-based phone systems, and to be independent by
controlling items such as televisions and electrical appliances.
• Conclusively, BCI has proved to be a boon for paralyzed
patients .
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35. ACKNOWLEDGEMENT
Most importantly, I would like to thank GB ma’am for
giving technical based topics which helped us in a big
way to get to know more of the core concepts.
Pratishruti Jain 35
