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Brain Computer Interface

Submitted in partial fulfilment of the requirement

for the award of the degree of MASTER OF COMPUTER

APPLICATIONS

HMR INSTITUTE OF TECHNOLOGY AND MANAGEMENT.

GURU GOBIND SINGH INDRAPRASTHA UNIVERSITY

Under the guidance of Submitted By:

Mr.Hiten Singh

Amit Kumar

DESIGNATION:Lecturer Enrollement no: 05013304409

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CERTIFICATE

This is to certify that the dissertation/project report () entitled Brain Machine Interface

done by Mr Hiten Singh, Roll No.05013304409 is an authentic work carried out by her/his at

HMR Institute of Technology and Management under my guidance. The matter embodied in

this report has not been submitted earlier for the award of any degree to the best of my

knowledge and belief.

Date: Signature of the Guide

NAME:Mr Hiten Singh

Designation:Lecturer

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ACKNOWLEDGEMENT

I would like to thank my Guide, Mr Hiten Singh, for his timely and valuable guidance and

direction for this work. It has been a great learning experience working under her supervision.

Her vast domain knowledge helped me to have deep insight on the subject. Her suggestion

and recommendations from time to time helped me immensely. She continuously encouraged

me while doing the project work and throughout the preparation of the report.

I would also like to thank the committee members and other staff members of the University

for their Support. Further I would like to thank my friends and family member for providing

unrelenting encouragement throughout the preparation of the report.

Date: 04.10.2011 NAME:Amit

(MCA 5 th Semester)

Enroll. No. :05013304409

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ABSTRACT

A brain-computer interface (BCI), sometimes called a direct neural interface or a brain-

machine interface, is a direct communication pathway between a human or animal brain and

an external device. In one-way BCIs, computers either accept commands from the brain or

send signals to it (for example, to restore vision) but not both. Two-way BCIs would allow

brains and external devices to exchange information in both directions but have yet to be

successfully implanted in animals or humansIn this definition, the word brain means the brain

or nervous system of an organic life form rather than the mind. Computer means any

processing or computational device, from simple circuits to silicon chips. Research on BCIs

began in the 1970s, but it wasn't until the mid-1990s that the first working experimental

implants in humans appeared. Following years of animal experimentation, early working

implants in humans now exist, designed to restore damaged hearing, sight and movement.

With recent advances in technology and knowledge, pioneering researchers could now

conceivably attempt to produce BCIs that augment human functions rather than simply

restoring them, previously only a possibility in science fiction Brain-machine interfaces

promise to aid paralyzed patients by re-routing movement-related signals around damaged

parts of the nervous system. A new study demonstrates a human with spinal injury

manipulating a screen cursor and robotic devices by thought alone. Implanted electrodes in

his motor cortex recorded neural activity, and translated it into movement commands. A

second study, in monkeys, shows that brain-machine interfaces can operate at high speed,

greatly increasing their clinical potential.

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TABLE OF CONTENTS

CHAPTER Page No

Title Page. ...i

Certificate....ii

Acknowledgement......iii

Abstract.......iv

Chapter1 INTRODUCTION.1

Chapter23

2.1 General Principal Behind BCI 9

2.2 Schematic of Brain Computer BCI..11

2.3Types of BCI...........................................................................................................13

2.3.1 INVASIVE BCI

2.3.2 NON INVASIVE BCI

2.4 History.......................................................................................................................14

Chapter 3..17

3.1 Human Brain..............................................................................................................18

3.2 Different sections of Brain.........................................................................................19

3.2.1 Diffrerent parts of Brain Stem

Chapter4..21

4.1 Cognitive Engineering

Chapter 5..25

5.1Brain Gate

5.2 Darpa...............................................................................................................................26

Chapter 6 BCI Application.27

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6.1 Introduction

6.2. Brain Gate

6.3 BCI offers treatment to paralyzed..............................................................................28

Chapter 7....29

7.1 BCI Advantages

7.2 BCI Disadvantages

Chapter8 Conclusion..30

Chapter 9 References..31

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Chapter 1.

INTRODUCTION

Man machine interface has been one of the growing fields of research and

development in recent years. Most of the effort has been dedicated to the design of user-

friendly or ergonomic systems by means of innovative interfaces such as voice recognition,

virtual reality. A direct brain-computer interface would add a new dimension to man-machine

interaction. interface, is a direct communication pathway between a human or animal brain(or

brain cell culture) and an external A brain-computer interface, sometimes called a direct

neural interface or a brain machine device. In one BCIs, computers either accept commands

from the brain or send signals to it but not both. Two way BCIs will allow brains and external

devices to exchange information in both directions but have yet to be successfully implanted

in animals or humans. Brain-Computer interface is a staple of science fiction writing. In its

earliest incarnations no mechanism was thought necessary, as the technology seemed so far

fetched that no explanation was likely. As more became known about the brain however, the

possibility has become more real and the science fiction more technically sophisticated.

Recently, the cyberpunk movement has adopted the idea of 'jacking in', sliding 'biosoft' chips

into slots implanted in the skull(Gibson, W.1984).Although such biosofts are still science

fiction, there have been several recent steps toward interfacing the brain and computers.

In this definition, the word brain means the brain or nervous system of an organic life form

rather than the mind. Machine means any processing or computational device, from simple

circuits to silicon chips (including hypothetical future technologies like quantum computing).

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Machine means any processing or computational device, from simple circuits to silicon chips

(including hypothetical future technologies like quantum computing). Research on BCIs has

been going on for more than 30 years but from the mid 1990s there has been dramatic

increase working experimental implants. The common thread throughout the research is the

remarkable cortical-plasticity of thebrain, which often adapts to BCIs treating prostheses

controlled by implants and natural limbs.With recent advances in technology and knowledge,

pioneering researches could now conceivably attempt to produce BCIs that augment human

functions rather than simply restoring them, previously only the realm of science fiction.

Chapter 2

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2.1. GENERAL PRINCIPLE BEHIND BCI

Main principle behind this interface is the bioelectrical activity of nerves and muscles. It is

now well established that the human body, which is composed of living tissues, can be

considered as a power station generating multiple electrical signals with two internal sources,

namely muscles and nerves. We know that brain is the most important part of human body. It

controls all the emotions and functions of the human body. The brain is composed of millions

of neurons. These neurons work together in complex logic and produce thought and signals

that control our bodies. When the neuron fires, or activates, there is a voltage change across

the cell,(~100mv) which can be read through a variety of devices. When we want to make a

voluntary action, the command generates from the frontal lobe. Signals are generated on the

surface of the brain. These electric signals are different in magnitude and frequency. By

monitoring and analyzing these signals we can understand the working of brain. When we

imagine ourselves doing something, small signals generate from different areas of the brain.

These signals are not large enough to travel down the spine and cause actual movement.

These small signals are, however, measurable. A neuron depolarizes to generate an impulse;

this action causes small changes in the electric field around the neuron. These changes are

measured as 0 (no impulse) or 1 (impulse generated) by the electrodes. We can control the

brain functions by artificially producing these signals and sending them to respective parts.

This is through stimulation of that part of the brain, which is responsible for a particular

function using implanted electrodes.

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Fig 2.1 BCI Mechanism

Scientific progress in recent years has successfully shown that, in principle, it is feasible to

drive prostheses or computers using brain activity. The focus of worldwide research in this

new technology, known as Brain Machine Interface or Brain Computer Interface, has been

based on two different prototypes: Non-invasive Brain Machine Interfaces, which measure

activity from large groups of neurons with electrodes placed on the surface of the scalp

(EEG), and Invasive Brain Machine Interfaces, which measure activity from single neurons

with miniature wires placed inside the brain. Every mental activityfor example, decision

making, intending to move, and mental arithmeticis accompanied by excitation and

inhibition of distributed neural structures or networks. With adequate sensors, we can record

changes in electrical potentials, magnetic fields, and (with a delay of some seconds)

metabolic supply Consequently, we can base a Brain Computer Interface on electrical

potentials, magnetic fields, metabolic or haemodynamic recordings. To employ a BCI

successfully, users must first go through several training sessions to obtain control over their

brain potentials (waves) and maximize the classification accuracy of different brain states. In

general, the training starts with one or two predefined mental tasks repeated periodically. In

predefined time we record the brain signals and use them for offline analyses. In this way, the

computer learns to recognize the users mental-task-related brain patterns. This learning

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process is highly subject specific, so each user must undergo the training individually. Visual

feedback has an especially high impact on the dynamics of brain oscillations that can

facilitate or deteriorate the learning process.

2.2. SCHEMATIC OF A BRAIN COMPUTER INTERFACE

Brain Computer Interface (BCI) is a collaboration between a brain and a device that enables

signals from the brain to direct some external activity, such as control of a cursor or a

prosthetic limb. The interface enables a direct communication pathway between the brain and

the object to be controlled. In the case of cursor control, for example, the signal is transmitted

directly from the brain to the mechanism directing the cursor, rather than taking the normal

route through the body's neuromuscular system from the brain to the finger on a mouse.

Fig 2.2. Schematic of a Brain Computer Interface (BCI) System.

By reading signals from an array of neurons and using computer chips and programs to

translate the signals into action, Brain Computer Interface can enable a person suffering from

paralysis to write a book or control a motorized wheelchair or prosthetic limb through

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Shrinking electronics and faster computers made his artificial eye more portable and allowed

him to perform simple tasks unassisted. BCIs focusing on motor Neuroprosthetics aim to

either restore movement in paralyzed individuals or provide devices to assist them, such as

interfaces with computers or robot arms.

2.3.2. Non-Invasive BCI:

As well as invasive experiments, there have also been experiments in humans using non-

invasive neuroimaging technologies as interfaces. Signals recorded in this way have been

used to power muscle implants and restore partial movement in an experimental volunteer.

Although they are easy to wear, non-invasive implants produce poor signal resolution

because the skull dampens signals, dispersing and blurring the electromagnetic waves created

by the neurons

Fig.2.3: Recordings of brainwaves produced by an electroencephalogram

Electroencephalography(EEG) is the most studied potential non-invasive interface, mainly

due to its fine temporal resolutions, ease of use, portability and low set-up cost. But as well as

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the technology's susceptibility to noise, another substantial barrier to using EEG as a brain-

computer interface is the extensive training required before users can work the technology.

2.4. History

Studies that developed algorithms to reconstruct movements from motor cortex neurons, which

control movement, date back to the 1970s. Work by groups led by Schmidt, Fetz and Baker in the

1970s established that monkeys could quickly learn to voluntarily control the firing rate of

individual neurons in the primary motor cortex after closed-loop operant conditioning, a training

method using punishment and rewards.

In the 1980s, Apostolos Georgopoulos at Johns Hopkins University found a mathematical

relationship between the electrical responses of single motor-cortex neurons in rhesus macaque

monkeys and the direction that monkeys moved their arms (based on a cosine function). He also

found that dispersed groups of neurons in different areas of the brain collectively controlled

motor commands but was only able to record the firings of neurons in one area at a time because

of technical limitations imposed by his equipment.

There has been rapid development in BCIs since the mid-1990s. Several groups have been able to

capture complex brain motor centre signals using recordings from neural ensembles (groups of

neurons) and use these to control external devices, including research groups led by Richard

Andersen, John Donoghue, Phillip Kennedy, Miguel Nicolelis, and Andrew Schwartz. Phillip

Kennedy and colleagues built the first intracortical brain-computer interface by implanting

neurotrophic-cone electrodes into monkeys.

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Fig.2.4.: Garrett Stanley's recordings of cat vision using a BCI implanted in the lateral geniculate

nucleus (top row: original image; bottom row: recording)

In 1999, researchers led by Garrett Stanley at Harvard University decoded neuronal firings to

reproduce images seen by cats. The team used an array of electrodes embedded in the thalamus

(which integrates all of the brains sensory input) of sharp-eyed cats. Researchers targeted 177

brain cells in the thalamus lateral geniculate nucleus area, which decodes signals from the retina.

The cats were shown eight short movies, and their neuron firings were recorded. Using

mathematical filters, the researchers decoded the signals to generate movies of what the cats saw

and were able to reconstruct recognisable scenes and moving objects.Miguel Nicolelis has been a

prominent proponent of using multiple electrodes spread over a greater area of the brain to obtain

neuronal signals to drive a BCI. Such neural ensembles are said to reduce the variability in output

produced by single electrodes, which could make it difficult to operate a BCI.After conducting

initial studies in rats during the 1990s, Nicolelis and his colleagues developed BCIs that decoded

brain activity in owl monkeys and used the devices to reproduce monkey movements in robotic

arms. Monkeys have advanced reaching and grasping abilities and good hand manipulation skills,

making them ideal test subjects for this kind of work. By 2000, the group succeeded in building a

BCI that reproduced owl monkey movements while the monkey operated a joystick or reached

for food.The BCI operated in real time and could control a separate robot remotely over Internet

protocol. But the monkeys could not see the arm moving and did not receive any feedback, a so-

called open-loop BCI.

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Inside the cortex, the cerebrum is largely made up of white matter. White matter is tissue

made only of nerve fibres. The middle region is deep inside the brain. It's chief purpose is to

connect the front and the back of the brain together. It acts as a "switchboard", keeping the

parts of your brain in touch with each other. The back area of the brain is divided into three

different partsThe pons is a band of nerve fibres which link the back of the brain to the

middle. The cerebellum sees to it that all the parts of your body work as a team. It also makes

sure you keep your balance. The medulla is low down at the back of your head. It links the

brain to the top of the spinal cord. The medulla controls the way your heart pumps blood

through your body. It also looks after your breathing and helps you digest food.

3.2.1. The Differet Part of the Brain Stem:

The brainstem is one of the oldest parts of the brain. It controls such functions as breathing,

blood pressure, swallowing and heart rate.

THE HYPOTHALMUS: This part of the brain is located directly above the brain stem.

The hypothalmus controls basic drives like hunger and sex and as well as our response to

threat and danger. The hypothalmus also controls the pituitary.

THE PITUITARY: The pituitary produces hormones such as testosterone that circulate

throughout the body. THE THALAMUS: The thalamus is like a relay area; it receives

messages from lower brain areas such as the brainstem and hypothalamus and sends them to

the two brain hemispheres. The thalamus is located in between above the lower brain and

under the two hemispheres.

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Most of the above mentioned parts of the brain were produced early in evolution but the

higher mammals especially humans went on to produce a sort of "thinking cap" on top of

these parts. This "thinking cap" was divided into two different parts, the left hemisphere and

the right hemisphere. If the left side of your brain is more developed like most people's are,

you are right handed. On the other hand if the right side of your brain is more developed, then

you will be left handed. The right side of your brain is more artistic and emotional while the

left side of your brain is your "common sense" and practical side, such as figuring out math

and logic problems.

THE CEREBELLUM: One of the most important parts of the Human brain is the

cerebellum. The cerebellum is involved with the more complex functions of the brain and

sometimes is even referred to as "the brain within the brain". The cerebellum acts as a control

and coordination centre for movement. The cerebellum carries small "programs" that have

been previously learned. For example, how to write, move, run and jump are all previously

learned activities that the brain recorded and can playback when needed.

Every time you practice, the brain rewrites the program and makes it better. You may have

heard the saying "practice makes perfect". Well this saying is not entirely true; another way

of "practicing" is just to imagine what you wish to do. Since the cerebellum can't actually

feel, it will think that you are doing what your imagining and respond by rewriting it's

previous program and carrying out any other actions needed for that function. This is one

why to explain wet dreams.

THE CEREBRAL CORTEX: The cerebral cortex makes up the top of the two hemispheres

of the brain. The cortex is a sheet of greyish matter which produces our thoughts, language

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and plans. It also controls our sensations and voluntary movements, stores our memories and

gives us the ability to imagine, in short it's what makes humans, humans.

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and a reference electrode. The peak-to-peak amplitude of the waves that can be picked up

from the scalp is normally 100 microV or less while that on the exposed brain, is about 1mV.

The frequency varies greatly with different behavioural states. The normal EEG frequency

content ranges from 0.5 to 50 Hz. Frequency information is particularly significant since the

basic frequency of the EEG range is classified into five bands for purposes ofEEG analysis.

These bands are called brain rhythms and are named after Greek letters.

Five brain rhythms are displayed in Table.. Most of the brain research is concentrated in these

channels and especially alpha and beta bands are important for BCI research. The reason why

the bands do not follow the greek letter magnitudely (alpha is not the lowest band) is that this

is the order in which they were discovered.

Fig.4.1. Different waves f brains

Fig.4.2. Different location of electrodes of EEG Fig.4.3. EEG Chart

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fMRI

It stands for Functional Magnetic Resonance Imaging. fMRI is based on the same technology

asmagnetic resonance imaging(MRI) -- a noninvasive test that uses a strong magnetic

field and radio waves to create detailed images of the body. But instead of creating images of

organs and tissues like MRI, fMRI looks at blood flow in the brain to detect areas of activity.

These changes in blood flow, which are captured on a computer, help doctors understand

more about how the brain works.

fMRI is based on the idea that blood carrying oxygen from the lungs behaves differently in a

magnetic field than blood that has already released its oxygen to the cells. In other words,

oxygen-rich blood and oxygen-poor blood have a different magnetic resonance. Scientists

know that more active areas of the brain receive more oxygenated blood. The fMRI picks up

this increased blood flow to pinpoint greater activity. The measurement of blood flow, blood

volume and oxygen use is called the blood-oxygen-level-dependent (BOLD) signal.

When you lie inside the cylindrical MRI machine, it aims radio waves at protons --

electrically charged particles in the nuclei of hydrogen atoms -- in the area of your body

being studied. As the magnetic field hits the protons, they line up. Then the machine releases

a short burst of radio waves, which knocks the protons out of alignment. After the radio-wave

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burst has ended, the protons fall back in line, and as they do, they release signals that the MRI

picks up. The protons in areas of oxygenated blood produce the strongest signals.

A computer processes these signals into a three-dimensional image of the brain that doctors

can examine from many different angles. Brain activity is mapped in squares called voxels.

Each voxel represents thousands ofnerve cells (neurons). Color is added to the image to

create a map of the most active areas in the brain.

This application determines which parts of the brain handle particular functions. For example,

researchers are trying to identify the regions of the brain that handle pain, in order to create

more effective pain relieving therapies. Other researchers are looking at where in the

brain time is perceived, to create new treatments for people who have difficulty with time

perception.

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Chapter 5.

5.1. Brain Gate

fig.4.1:Dummy unit illustrating the design of a Brain Gate interface

Brain Gate is a brain implant system developed by the bio-tech company Cyber kinetics in

2003 in conjunction with the Department of Neuroscience at Brown University. The device

was designed to help those who have lost control of their limbs, or other bodily functions,

such as patients with amyotrophic lateral sclerosis (ALS) or spinal cord injury. The computer

chip, which is implanted into the brain, monitors brain activity in the patient and converts the

intention of the user into computer commands.

Currently the chip uses 100 hair-thin electrodes that sense the electro-magnetic signature of

neurons firing in specific areas of the brain, for example, the area that controls arm

movement.

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Chapter 6

BCI Applications

6.1. Introduction

After we go through the various techniques of BCI the first question that comes to our mind

is, what does BCI do to us and what are its applications.So BCI in todays time turns useful to

us in many ways. Whether it be any medical field or a field leading to enhancement of human

environment.

Some of the BCI applications:

6.2.BRAINGATE

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. The device

was designed to help those who have lost control of their limbs, or other bodily functions,

such as patients with amyotrophic lateral sclerosis (ALS) or spinal cord injury. The computer

chip, which is implanted into the brain, monitors brain activity in the patient and converts the

intention of the user into computer commands.

Currently the chip uses 100 hair-thin electrodes that sense the electro-magnetic signature of

neurons firing in specific areas of the brain, for example, the area that controls arm

movement capable of recording electrical data for later analysis. A potential use of this

feature would be for a neurologist to study seizure patterns in a patient with epilepsy.

Cyberkinetics has a vision, CEO Tim Surgeon explained to Gizmag, but it is not promising

"miracle cures", or that quadriplegic people will be able to walk again - yet. Their primary

goal is to help restore many activities of daily living that are impossible for paralysed people

and to provide a platform for the development of a wide range of other assistive devices.

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"Today quadriplegic people are satisfied if they get a rudimentary connection to the outside

world. What we're trying to give them is a connection that is as good and fast as using their

hands. We're going to teach them to think about moving the cursor using the part of the brain

that usually controls the arms to push keys and create, if you will, a mental device that can

input information into a computer. That is the first application, a kind of prosthetic, if you

will. The applications are discussed below.

6.2. BCI offers treatment to Paralyzed

Tuebingen, Germany. A braincomputer interface installed early enough in patients with neuron-

destroying diseases can enable them to be taught to communicate through an electronic device

and slow destruction of the nervous system. Fundamental theories regarding consciousness,

emotion and quality of life in sufferers of paralysis from Amyotrophic Lateral Sclerosis (ALS,

also known as 'Lou Gerhig's disease') are being challenged based on new research on brain-

computer interaction. ALS is a progressive disease that destroys neurons affecting movement

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7.1 BCI ADVANTAGES

1. BCIs will help creating a direct communication pathway between a human or animalbrain and any external devices like computers.

2. BCI has increased the possibility of treatment of disabilities related to nervous systemalong with the old technique of Neuroprosthetics.3. Techniques like EEG, MEG and neurochips have come into discussions since the BCI

application have started developing.

4. This has provided a new work area for scientists and researchers around the world

7.2 BCI DISADVANTAGES

1. In case of Invasive BCI there is a risk of formation of scar tissue.2. There is a need of extensive trainin g before user can use techniques

like EEG

3. BCI techniques still requi re much enhancement before they can be usedby users as they are slow

4. BCI techniques are costly. It requires a lot of money to set up the BCIenvironment

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CONCLUSION

Brain-Computer Interface (BCI) is a method of communication based on voluntary neural activity

generated by the brain and independent of its normal output pathways of peripheral nerves and

muscles.The neural activity used in BCI can be recorded using invasive or noninvasive

techniques. We can say as detection techniques and experimental designs improve, the BCI will

improve as well and would provide wealth alternatives for individuals to interact with their

environment.

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REFERENCES: WWW.HOWSTUFFWORKS.COM WWW.WIKEPEDIA.COM WWW.YOUTUBE.COM WWW.Scribd.com