The document discusses BrainGate technology, which involves implanting a neuroprosthetic device into the brain that can detect brain signals and convert them into computer commands. It describes how BrainGate was developed in 2003 and involves implanting an electrode array on the motor cortex. The underlying principle is that intact brain function generates neural signals even if they can't be sent to the limbs. It explains how the device works by sending brain activity data through wires to a computer for processing and allows paralyzed individuals to control external devices with their thoughts.

1. SEMINAR BY:
NAMRATA KOLEY(C.S.E. III YEAR)
OM DAYAL GROUP OF INSTITUTION,ULUBERRIA
WEST BENGAL

2. INTRODUCTION
What is Brain Gate Technology?
• Brain gate is a neuroprosthetic device that converts
brain activity into computer commands.
• This system is designed to help those
who have lost control of their limbs,
or other bodily functions, such as patients
with amyotropic lateral sclerosis (ALS) or
spinal cord injury.

3. DEVELOPMENT
BrainGate is a brain implant system developed by the bio-tech
company Cyberkinetics in 2003 in conjunction with the
Department of Neuroscience at Brown University .
In July 2009, a second clinical trial (dubbed "BrainGate2") was
initiated by researchers at Massachusetts General Hospital,
Brown University, and the Providence VA.
Judy Hackett Jeff Stibel Nicholas Hatsopoulos

4. UNDERLYING PRINCIPLE
The brain is hardwired with connections, which are made by
billions of neurons that make electricital signals whenever
they are stimulated.
”The principle of operation of the
BrainGate Neural Interface System
is that with intact brain function,
neural signals are generated even
though they are not sent to the arms,
hands and legs”.

5. WORKING
A sensor is implanted on the brain, and electrodes are hooked up to wires
that travel to a pedestal on the scalp. From there, a fiber optic cable carries
the brain activity data to a preprocessor ,then digitizer and then to a nearby
computer.

6. WORKING ALGORITHM

7. NEUROCHIP
The chip uses 100 hair-thin electrodes that 'hear' neurons firing in specific
areas of the brain It is made of silicon that is doped in such a way that it
contains EOSFETs (that can sense the electrical activity of the neurons. It
also contains capacitors for the electrical stimulation of the neurons. It is
embeddedd in primary motor cortex region .

8. INVASIVE
 Invasive BCIs are implanted directly into the
grey matter of the brain during neurosurgery .
 Invasive BCI provides the highest quality of
signals among BCIs but are prone to scar –tissue
build- ups.
PARTIALLY INVASIVE
Partially invasive BCI devices are implanted inside the skull but rest outside
the brain rather than within the grey matter. They produce better resolution
signals than non-invasive BCIs where the bone tissue of the cranium deflects
and deforms signals and have a lower risk of forming scar-tissue
Eg:::::ELECTROCORTICOGRAPH (ECoG)
NON -INVASIVE
No break in the skin is made .Activities are carried out on the scalp.
Eg :Electroencephalography(EEG)
Magnetoencephalography(EEG)

9. PREPROCESSING
• The raw EEG signal requires some preprocessing before the
feature extraction. This preprocessing includes removing
unnecessary frequency bands, averaging the current brain activity
level, transforming the measured scalp potentials to cortex
potentials and denoising. Frequency bands of the EEG :
Band Frequecny [Hz] Amplitude Location
Alpha (_) 8-12 10 -150 Occipital/
Parietal regions
μ-rhythm 9-11 varies Precentral/
Postcentral
regions
Beta (_) 14 -30 25 typically
Frontal regions
Theta (_) 4-7 varies varies
Delta (_) <3 varies varies

10. DETECTION
• The detection means to try to find out these mental tasks from the EEG
signal. It can be done in time-domain, e.g. by comparing amplitudes of
the EEG and in frequency-domain. This involves usually digital signal
processing for sampling and band pass filtering the signal, then
calculating these time -or frequency domain features and then
classifying them.
• These classification algorithms include simple comparison of amplitudes
linear and non-linear equations and artificial neural networks. By
constant feedback from user to the system and vice versa, both partners
gradually learn more from each other and improve the overall
performance.

11. CONTROL
The final part consists of applying
the will of the user to the used
application. The user chooses an
action by controlling his brain
activity, which is then detected
and classified to corresponding
action. Feedback is
provided to user by audio-visual
means

12. TRAINING
The training is the part where the
user adapts to the BCI system.
This training begins with very simple
exercises where the user is familiarized
with mental activity which is used to
relay the information to the computer.
Motivation, frustration, fatigue, etc.
apply also here and their effect should
be taken into consideration when
planning the training procedures.Users
learn over a series of 40-min sessions
to control the cursor.
They participate in 2–3 sessions
per week for about six months.

13. BIO FEEDBACK
• The definition of the biofeedback is biological
information which is returned to the source
that created it, so that source can understand
it and have control over it. This biofeedback
in BCI systems is usually provided by visually,
e.g. the user sees cursor moving up or down
or letter being selected from the alphabet.

14. COMPONENTS
NEUROCHIP
CONNECTOR(PEDESTAL)
PREPROCESSING SECTION
COMPUTER
EXERNAL DEVICES

15. Software behind Brain Gate…
The computers translate brain activity and
create the communication output using custom
decoding software.
System uses translation algoithm in which
a linear equation translates mu-rhythm or
beta-rhythm into cursor movement of
10 times/s,adaptive algorithms and
pattern-matching techniques to facilitate
communication. The algorithms are written in C,
JAVA and MATLAB

16. DENOISING AMPLIFIER
averaging the current brain
activity level
Measure scalp potentials to
cortex potentials
removing unnecessary
frequency bands

17. CURSOR
In our brain–computer interface (BCI) people
motor disabilities learn to control mu- and/or
beta-rhythm amplitudes to move a cursor in
one or two dimensions to choices on a
computer screen
the user controls vertical cursor movement by
controlling the amplitude of a 12-Hz mu
rhythm focused over left
sensorimotor cortex.
With this control, users can move the cursor to
answer spoken yes/no questions with
accuracies >95%

19. DO YOU WANT TO MOVE YOUR HAND
RIGHT?
• YES N O

21. Brain Gate Research in animals:
At first, rats were
implanted with BCI .
Signals recorded from
the cerebral cortex of rat
to operate BCI to carry
out the movement.

22. Researchers at the University of Pittsburgh had demonstarted on
a monkey that can feed itself with a robotic arm simply by using
signals from its brain. Using only its mind the monkey was able
to control a cursor on a computer monitor via Brain Gate.

23. APPLICATIONS:
In Foxborough, a 25-
year-old quadriplegic sits
in a wheelchair with
wires coming out of a
bottle-cap-size connector
stuck in his skull. The
wires run from 100 tiny
sensors implanted in his
brain and out to a
computer. Using just his
thoughts, he was playing
the computer game Pong.

26. CONCLUSION
 According to the Cyberkinetics' website, two patients have been implanted
with the Brain Gate system.
 Using the system, called Brain Gate, the patient can read e-mail, play video
games, turn lights on or off and change channels or adjust the volume of a
television set.
 In early test sessions, the patient was able to control the TV and carry on a
conversation and move his head at the same time.
 The results are spectacular and almost unbelievable.
 Brain Gate can help paralyzed people move by controlling their own electric
wheelchairs, communicate by using e-mail and Internet-based phone systems,
and be independent by controlling items such as televisions and thermostats.
 Finally BRAIN GATE has proved to be a boon for paralyzed patient .