1. A
Presentation
On
Prepared by
Mr.Rushi Prajapati
Monday, June 04, 2012 BCI A.I.E.T. Jaipur 1

2. Scope of presentation
Basic Idea
Generic BCI system
Types of BCI system
EEG technique
Applications
Advantages
Disadvantages
BCI Innovators
Future developments
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3. MAN AND THE WORLD
Man interacts with the world using his
five senses and limb movements
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4. THOUGHTS faster than
ACTIONS
 Actions are mechanical
movements while
thoughts are electrical
impulses.
 Thoughts are faster than
actions
 So direct interaction with
the world through
thoughts would be faster.
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5. Brain Computer Interface
 Brain-computer interface (BCI) is a fast-growing
emergent technology in which researchers aim to
build a direct channel between the human brain
and the computer.
BCI- The
Ultimate in
Human
Computer
Interfacing
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6. Components of BCI
Generation of
signals from brain
Preprocessing,
Feature extraction,
Classification,
Device control.
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7. Generic BCI System
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8. signal extraction techniques
Different neuroimaging methods are used to derive
meaningful interpretations from the brain signals which
are captured by microelectrodes:
EEG - Electro encephalography
ECoG - Electro cortico graphy
MEG - Magneto encephalo graphy
BOLD - Blood-Oxygen-Level-Dependent (signal)
MRI - Magnetic Resonance Imaging
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9. Types of BCI
Invasive-
inside grey matter of brain
Partially Invasive-
inside the skull but outside
the grey matter
Non Invasive-
outside the skull, on the
scalp
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10. Invasive BCI S
Electrode inserted
directly into grey matter
Highest quality signal
can obtain
But are prone to scar-
tissue build-up
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11. Sensors Used in BCI-
Microelectrodes
Silicon Microelectrode
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12. Microelectrodes
Microelectrodes are
used to capture
electrical/magnetic
signals of the brain.
Types:
Wire-type
Silicon-based
Ceramic-based
Polyimide-based. Diagram of silicon-based
ACREO microelectrode arrays
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13. Microwires emerging from the green and orange tubes connect to two
arrays of 16 microelectrodes embedded in a small mat of clear,
rubbery silicone - the larger, numbered electrodes are part of the
patient’s original surgery (Photo: University of Utah Department of
Neurosurgery) Monday, June 04, 2012 BCI 13

14. Partially Invasive BCIs
 Implanted inside the skull but rest outside the grey
matter of the brain
 Produce better resolution signals than non-invasive
BCIs where the bone tissue of the cranium deflects
and deforms signals
 Carry lower risk of forming scar-tissue in the brain
than fully-invasive BCIs.
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15. Non-Invasive BCIs
 low signal quality due
to electrodes are not
directly interact with
neurons
 It is safest as no
surgery required.
 EEG is widely used for
this technique
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16. EEG Technique for BCI
 Electrodes attached to the
scalp
 Electric signals of the brain
are amplified.
 Transmitted to the computer
 Software converts them into
technical control signals (
computer commands)
 These computer commands
controls the computer. June 04, 2012
Monday, BCI 16

17. EEG WAVES
There are 5 major types of EEG waves
1. Delta Waves
2. Theta Waves
3. Alpha Waves
4. Beta Waves
5. Gamma Waves
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18. Continuous Brain Waves
 Generally grouped by frequency: (amplitudes are about 100µV max)
Type Frequency Location Use
Delta <4 Hz everywhere occur during sleep, coma
Theta 4-7 Hz temporal and parietal correlated with emotional stress
(frustration & disappointment)
Alpha 8-12 Hz occipital and parietal reduce amplitude with sensory
stimulation or mental imagery
Beta 12-36 Hz parietal and frontal can increase amplitude during
intense mental activity
Mu 9-11 Hz frontal (motor diminishes with movement or
cortex) intention of movement
Lambda sharp, occipital correlated with visual attention
jagged
Vertex higher incidence in patients with
epilepsy or encephalopathy
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19. Electrode Placement
 Standard “10-20 System”
 Spaced apart 10-20%
 Letter for region
• F - Frontal Lobe
• T - Temporal Lobe
• C - Center
• O - Occipital Lobe
 Number for exact position
• Odd numbers - left
• Even numbers - right
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20. Electrode Placement
 A more detailed view:
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21. Area of implementation
Medical science
 Enabling disabled people
o Vision and hearing
o Paralysis treatment
o Prosthetic devices (legs, hands etc)
o Provide a means of communication to completely
paralyzed patients
o Surgically implanted devices used as replacement
for paralyzed patients 04, 2012 BCI
Monday, June 21

22. General application
Control a robot
Playing games
For physically weak persons to handle the computer
Cursor control
o Allow those with poor muscle control to
o communicate and control physical devices
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23. Example of BCI
application
A phsically
handicapped
man operates
a BCI
wheelchair
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24. More examples
Japanese student
walking in the virtual
world with the
character controlled
by his brain waves.
A single handed man
interfaced with BCI
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25. ADVANTAGES
• BCIs will help creating a Direct communication
between a human or animal brain and computers.
• Also it provides better living, more features, more
advancement in technologies etc.
• High Precision (can be used reliably)
• Low bandwidth
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26. Difficulty in Implementation
of BCI:
 COST require for BCI is very high.
 It is RISKy, because it operates with brain.
 Effective BCI technique requires invasive method.
 Requires magnetically shielded room and special
kind of helmet.
 It is SLOW
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27. BCI INNOVATORS
 Pioneers
 Nasa
 Cyberkinetics neurotechnology system,
 Japanese reaserch team
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28. Future developments
 Better signal detection
 Shortening training time
 Improvinglearning (neurobiological and
psychological basis)
 New recording methods (NIRS, ECoG)
 Broaderrange of applications (interface to
commercially available assistive devices;
treatment of diseases)
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29. Conclusion
 BCI is highly promising.
 Provide high standard of
living.
 Extend our limits.
 Impart a new level to the
popular quote-
“I think therefore I am!”
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