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Brain Gate Technology
BRAIN GATE TECHNOLOGY
ABSTRACT:
BrainGate is a brain implant system developed by the bio-tech company Cyberkinetics in
2008 in conjunction with the Department of Neuroscience at Brown University. The mind-tomovement system that allows a quadriplegic man to control a computer using only his
thoughts is a scientific milestone. It was reached, in large part, through the brain gate system.
This system has become a boon to the paralyzed. 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 principle of operation behind the Brain Gate
System is that with intact brain function, brain signals are generated even though they are not
sent to the arms, hands and legs.The signals are interpreted and translated into cursor
movements, offering the user an alternate Brain Gate pathway to control a computer with
thought,just as individuals who have the ability to move their hands use a mouse. A longterm goal of the BrainGate research team is to create a system that, quite literally, turns
thought into action – and is useful to people with neurologic disease or injury, or limb loss.
Currently, the system consists of a “sensor” (a device implanted in the brain that records
signals directly related to imagined limb movement); a “decoder” (a set of computers and
embedded software that turns the brain signals into a useful command for an external device);
and, the external device – which could be a standard computer desktop or other
communication device, a powered wheelchair, a prosthetic or robotic limb, or, in the future, a
functional electrical stimulation device that can move paralyzed limbs directly.
The 'Brain Gate' contains tiny spikes that will extend down about one millimetre into the
brain after being implanted beneath the skull,monitoring the activity from a small group of
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neurons.It will now be possible for a patient with spinal cord injury to produce brain signals
that relay the intention of moving the paralyzed limbs,as signals to an implanted sensor,which
is then output as electronic impulses. These impulses enable the user to operate mechanical
devices with the help of a computer cursor. . Matthew Nagle,a 25-year-old Massachusetts
man with a severe spinal cord injury,has been paralyzed from the neck down since 2001.After
taking part in a clinical trial of this system,he has opened e-mail,switched TV channels,turned
on lights.He even moved a robotic hand from his wheelchair. This marks the first time that
neural movement signals have been recorded and decoded in a human with spinal cord
injury.The system is also the first to allow a human to control his surrounding environment
using his mind.
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1. INTRODUCTION
1.1 GENERAL
Brain and Neurons
Brain is the center of nervous system which is present inhead, protected by the skull.
#Brain controls the whole body actions and reactions.
#Neurons are the responsive cells in nervous system thatprocesses and transmits information
by electrochemicalsignals.
#There are 100 billion neurons are available in human body
Neurons and Nervous system
Neurons are the constituents of Nervous system and plays the vital role inour daily life.
#Neurons have very complex operation to perform and if it stops workingthen one cannot be
able to work.
#Nervous system is linked with Brain and is controlled by it. The commandsspecified by the
brain is carried to the various organs through them
How does the brain control motor function work?
The brain is "hardwired" with connections, which are made by billions of neurons that make
electricity whenever they are stimulated. The electrical patterns are called brain waves.
Neurons act like the wires and gates in a computer, gathering and transmitting
electrochemical signals over distances as far as several feet. The brain encodes information
not by relying on single neurons, but by spreading it across large populations of neurons, and
by rapidly adapting to new circumstances.
Motor neurons carry signals from the central nervous system to the muscles, skin and glands
of the body, while sensory neurons carry signals from those outer parts of the body to the
central nervous system. Receptors sense things like chemicals, light, and sound and encode
this information into electrochemical signals transmitted by the sensory neurons. And
interneurons tie everything together by connecting the various neurons within the brain and
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spinal cord. The part of the brain that controls motor skills is located at the ear of the frontal
lobe.
How does this communication happen? Muscles in the body's limbs contain embedded
sensors called muscle spindles that measure the length and speed of the muscles as they
stretch and contract as you move. Other sensors in the skin respond to stretching and
pressure. Even if paralysis or disease damages the part of the brain that processes movement,
the brain still makes neural signals. They're just not being sent to the arms, hands and legs.

A technique called neurofeedback uses connecting sensors on the scalp to translate
brain waves into information a person can learn from. The sensors register different
frequencies of the signals produced in the brain. These changes in brain wave patterns
indicate whether someone is concentrating or suppressing his impulses, or whether he
is relaxed or tense.
NEUROPROSTHETIC DEVICE:
A neuroprosthetic device known as Braingate converts brain activity into computer
commands. 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 nearby computer.
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1.2 HISTORY:

Research on BCIs has been going on for more than 30 years, but from the mid-1990s
there has been a dramatic increase in working experimental implants.

Brain gate was developed by the bio-tech company Cyberkinetics in 2003 in
conjuction with the Department of Neuroscience at Brown University.
Fig 1. Experiment on rat
Rats implanted with BCIs in Theodore Berger's experiments.Several laboratories have
managed to record romsignals f monkey and rat cerebral cortexes in order to operate BCIs to
carry out movement. Monkeys have navigated computer cursors on screen and commanded
robotic arms to perform simple tasks simply by thinking about the task and without any
motor output. Other research on cats has decoded visual signals.
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 brain’s 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 recognizable scenes and moving objects.
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In the 1980s, Apostolos Georgopoulos at Johns Hopkins University found a mathematical
relationship between the (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.
Fig 2. Diagram
of the BCI
Diagram of the BCI developed by Miguel Nicolelis and collegues for use on Rhesus onkeys
Later experiments by Nicolelis using rhesus monkeys, succeeded in closing the feedback loop
and reproduced monkey reaching and grasping movements in a robot arm. With their deeply
cleft and furrowed brains, rhesus monkeys are considered to be better models for human
neurophysiology than owl monkeys. The monkeys were trained to reach and grasp objects on
a computer screen by manipulating a joystick while corresponding movements by a robot arm
were hidden.The monkeys were later shown the robot directly and learned to control it by
viewing its movements. The BCI used velocity predictions to control reaching movements
and simultaneously predicted hand gripping force.
Other labs that develop BCIs and algorithms that decode neuron signals include John
Donoghue from Brown University, Andrew Schwartz from the University of Pittsburgh and
Richard Andersen from Caltech. These researchers were able to produce working BCIs even
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though they recorded signals from far fewer neurons than Nicolelis (15–30 neurons versus
50–200 neurons).
Donoghue's group reported training rhesus monkeys to use a BCI to track visual targets on a
computer screen with or without assistance of a joystick (closed-loop BCI). Schwartz's group
created a BCI for three-dimensional tracking in virtual reality and also reproduced BCI
control in a robotic arm.
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1.3 PRINCIPLE:
"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. These signals are interpreted by the System and a cursor is shown to the user on a
computer screen that provides an alternate "BrainGate pathway". The user can use that cursor
to control the computer, just as a mouse is used."
Fig 3. Brain Computer Interface
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 patient and converts the intention of the user into computer
commands.
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Fig 4. Brain Gate Technology
NUERO CHIP:
Fig 5. Nuero Chip
Currently the chip uses 100 hair-thin electrodes that 'hear' neurons firing in specific areas of
the brain, for example, the area that controls arm movement. The activity is translated into
electrically charged signals and are then sent and decoded using a program, which can move
either a robotic arm or a computer cursor. According to the Cyberkinetics' website, three
patients have been implanted with the BrainGate system. The company has confirmed that
one patient (Matt Nagle) has a spinal cord injury, whilst another has advanced ALS.
In addition to real-time analysis of neuron patterns to relay movement, the Braingate array is
also 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.
Braingate is currently recruiting patients with a range of neuromuscular and
neurodegenerative conditions for pilot clinical trials in the United States.
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The human brain is a parallel processing supercomputer with the ability to instantaneously
process vast amounts of information. BrainGate's™ technology allows for an extensive
amount of electrical activity data to be transmitted from neurons in the brain to computers for
analysis. In the current BrainGate™ system, a bundle consisting of one hundred gold wires
connects the array to a pedestal which extends through the scalp. The pedestal is connected
by an external cable to a set of computers in which the data can be stored for off-line analysis
or analyzed in real-time. Signal processing software algorithms analyze the electrical activity
of neurons and translate it into control signals for use in various computer-based applications.
Intellectual property has been developed and research is underway for a wireless device as
well.
Fig 6. Signal Processing
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1.4 BRAIN-COMPUTER INTERFACE
New research into how signals from the brain can be captured by a computer or other device
to carry out an individual's command may allow people with motor disabilities to more full
communicate and function in their daily lives.
The technique relies on the fact that multiple sensors acting together provide the central
nervous system with important feedback for controlling movement. For example, sensors
called muscle spindles that are embedded in muscle fibers measure the length and speed of
muscle stretch, while other sensors in the skin respond to stretch and pressure. When an
individual is paralyzed by injury or disease, neural signals from these sensors cannot reach
the brain, and thus cannot be used to control motor responses. Paralysis also keeps neural
signals originating in the motor regions of the brain from reaching the muscles.
The work of Weber and his colleagues shows that it is possible to extract feedback
information from the body's natural sensors that could then be used to control a prosthetic
device, allowing an individual to regain some command and control of his or her own
movements.
A sterile surgical procedure is used to implant arrays of 36 microelectrodes into the dorsal
root ganglion, part of the spinal nerve that contains the nerve cell bodies that house these
natural sensors. Historically, it was difficult to record from these sensors because their cell
bodies are located in this difficult-to-reach nerve bundle entering the spinal cord. The wires
from the microelectrode array are led out through the skin to a small electrical conductor. The
procedure allows simultaneous recordings from many sensory nerves during normal motor
activities such as walking. A digital camera tracks the position of the leg, and a mathematical
analysis relates ! the sensory activity to leg movement. The investigators found that fewer
than 10 neurons are needed to accurately predict the path of the leg. This finding is
encouraging because it suggests that a small number of neurons could provide the feedback
signals needed to control a prosthetic device.
"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. These signals are interpreted by the System and a cursor is shown to the user on a
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computer screen that provides an alternate "BrainGate pathway". The user can use that cursor
to control the computer, just as a mouse is used".
(From Forbidden Planet 1956)
Cyberkinetics has plans to implant the devices in 4 more subjects; the company cautions that
BrainGate is an investigational device for clinical testing only. It is not an approved device.
Development:Experiments were performed on dogs who were raised confined in cages. When released, the
dogs were excited, constantly ran around, and required several attempts to learn to avoid
pain. When pain such as a pinch or contact with a burning match was encountered, the
animals could not take action to avoid the stimulus immediately. This finding seemed to
demonstrate that pain is understood and avoided only by experience- aversion to it is not
inbuilt or automatic, and the organism has no way to know what will cause repeated pain
without a repeated experience.
Physiology:Afferent pain-receptive nerves, those that bring signals to the brain, comprise at least two
kinds of fibers - a fast, relatively thick, myelinated "A8" fiber that carries messages quickly
with intense pain, and a small, unmyelinated, slow "C" fiber that carries the longer-term
throbbing and chronic pain. Large-diameter Afi fibers are nonnociceptive and inhibit the
effects of firing by A8 and C fibers. The central nervous system has centers at which pain
stimuli can be regulated. Some areas in the dorsal horn of the spinal cord that are involved in
receiving pain stimuli from A8 and C fibers, called laminae, also receive input from Ap
fibers. In other parts of the laminae, pain fibers also inhibit the effects of nonnociceptive
fibers, 'opening the gate'.
An inhibitory connection may exist with AP and C fibers, which may form a synapse on the
same projection neuron. The same neurons may also form synapses with an inhibitory
interneuron that also synapses on the projection neuron, reducing the chance that the latter
will fire and transmit pain stimuli to the brain. The C fiber's synapse would inhibit the
inhibitory interneuron, indirectly increasing the projection neuron's chance of firing. The Ap
fiber, on the otherhand, forms an excitatory connection with the inhibitory interneuron, thus
decreasing the projection neuron's chance of firing (like the C fiber, the AP fiber also has an
excitatory connection on the projection neuron itself). Thus, depending on the relative rates
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of firing of C and AP fibers, the firing of the nonnociceptive fiber may inhibit the firing of
the projection neuron and the transmission of pain stimuliGate control theory thus explains
how stimulus that activates only nonnociceptive nerves can inhibit pain. The pain seems to be
lessened when the area is rubbed because activation of nonnociceptive fibers inhibits the
firing of nociceptive ones in the laminae In transcutaneous electrical stimulation (TENS),
nonnociceptive fibers are selectively stimulated with electrodes in order to produce this effect
and thereby lessen pain.
One area of the brain involved in reduction of pain sensation is the periaqueductal gray
matter that surrounds the third ventricle and the cerebral aqueduct of the ventricular system.
Stimulation of this area produces analgesia (but not total numbing) by activating descending
pathways that directly and indirectly inhibits nociceptors in the laminae of the spinal cord. It
also activates opioid receptor-containing parts of the spinal cord.
Afferent pathways interfere with each other constructively, so that the brain can control i the
degree of pain that is perceived, based on which pain stimuli are to be ignored to pursue J
potential gains. The brain determines which stimuli are profitable to ignore over time. Thus,
the brain controls the perception of pain quite directly, and can be "trained" to turn off forms
of pain that are not "useful". This understanding led Melzack to point out that pain is in the
brain.
Brain-computer interface:A brain-computer interface (BCI), sometimes called a direct neural interface or a brainmachine interface, is a direct technological interface between a brain and a computer not
requiring any motor output from the user. That is, neural impulses in the brain are intercepted
and used to control an electronic device. This is a rather broad, ill-defined term used to
describe many versions of conventional and theoretical interfaces. For purposes of this term,
the word brain is understood to imply the physical brain of an organic life form and computer
is understood to imply a mechanical/technological processing/computational device. These
semantic notations are crucial in the contemplation of a direct brain-computer interface, as
there is great debate in the philosophy of mind regarding the reduction of consciousness and
mind to the physical qualities of the brain. Because of cortical plasticity, the brain is likely to
adapt during learning to operate a BCI.
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Simple brain-computer interfaces already exist in the form of neuroprosthetics, with a great
deal of neuroscience, robotics, and computer science research currently dedicated to
furthering these technologies. Recent achievements demonstrate that it is currently possible to
implement crude brain-computer interfaces (brain dishes) that allow in vitro neuronal clusters
to directly control computers. Laboratories led by investigators Andrew Schwartz (U.
Pittsburgh), Richard Andersen (Caltech), Miguel Nicolelis (Duke), and John Donoghue
(Brown University) have all successfully used a variety of algorithms, including the vector
sum of motor cortical neuron spiking, to record directly from the cortex of monkeys to
operate a BCI. This design allowed a i monkey to navigate a computer cursor on screen, as
well as command a robotic arm to perform simple tasks, simply by thinking about moving the
cursor without any motor output from the monkey.
Studies that developed algorithms to reconstruct movements from the activity of motor cortex
neurons date back to the 1970s. Work by groups led by Schmidt, Fetz, and Baker in the 1970s
established that monkeys could quickly achieve voluntary control over the firing rate of
individual neurons in primary motor cortex under closed-loop operant conditioning. Phillip
Kennedy and colleagues built the first wireless, intracortical brain-computer interface by
implanting neurotrophic cone electrodes first into monkeys and then into the brains of
paralyzed patients. Several groups have explored real-time reconstruction of more complex
motor parameters using recordings from neural ensembles, including research groups lead by
Miguel Nicolelis, John Donoghue, Andrew Schwartz, Richard Andersen and more recently
Krishna Shenoy, Nicho Hatsopoulos, Ad Aertsen, Eilon Vaadia, Lee Miller, Andrew Fagg,
Dawn Taylor, and Eric Leuthardt.
BCIs in monkeys.
There has been explosive development in BCIs since the mid-1990s. Miguel Nicolelis has
been a prominent proponent of multi-unit, multi-area recordings from neural ensembles to
obtain high-quality neuronal signals to drive a BCI. After conducting initial studies in rats
during the 1990s, Nicolelis and his colleagues started to develop BCIs that decoded brain
activity in monkeys and used it to reproduce monkey movements in robotic arms. Monkeys
have advanced reaching and grasping abilities and good hand manipulation skills making the
ideal test subjects for this kind of work.
Nicolelis' group conducted their initial primate experiments using owl monkeys. By 2000,
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they had gained experience in implanting owl monkeys with electrode arrays in multiple <
brain areas and built a BCI that reproduced monkey movements while the monkey operated a
joystick or reached for food.
Later experiments led by Miguel Nicolelis on rhesus monkeys succeeded in closing the loop.
Rhesus monkeys are also considered to be better models for human neurophysiology than
owl monkeys. The monkeys were trained to reach and grasp objects on a computer screen by
manipulating a joystick .Their BCI used velocity predictions to control reaching movements.
The BCI simultaneously predicted hand gripping force. Reaching and grasping was produced
by a robot, which remained invisible to the monkeys. The feedback of the robot's
performance was provided by a visual display. Later, the monkeys learned to control the
robots directly using their implants while directly viewing the movement of the arm.
Other leading labs that develop BCIs and neuroprosthetic decoding algorithms include John
Donoghue from Brown University, Andrew Schwartz from the University of Pittsburgh and
Richard Andersen from Caltech. Although these researchers initially could not record from as
many neurons as Nicolelis and coworkers (15-30 neurons versus 50-200 neurons), they were
able to make important advances. A study by Donoghue's group reported that monkeys were
able to use the team's BCI without training to track visual targets on a computer screen.
Schwartz's group created a BCI for three-dimensional tracking (Taylor et al., 2002).
Andersen's group incorporated in their BMI design cognitive signals recorded in the posterior
parietal cortex, such as encoding of reaching the target and anticipated reward. John
Donoghue and Nicho Hatsopoulos also took this research to the business arena by starting
Cyberkinetics, the company that puts development of practical BCIs for humans as its major
goal.
In addition to predicting kinematic and kinetic parameters of limb movements, BCIs that
predict electromyographic activity of muscles are being developed (Santucci et al. 2005).
Such BCIs could be used in neuroprosthetic devices that restore mobility in paralyzed limbs
by electrical stimulation of muscles.
A brain–computer interface (BCI), often called a mind-machine interface (MMI), or
sometimes called a direct neural interface or a brain–machine interface (BMI), is a direct
communication pathway between the brain and an external device. BCIs are often directed at
assisting, augmenting, or repairing human cognitive or sensory-motor functions.
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Research on BCIs began in the 1970s at the University of California Los Angeles (UCLA)
under a grant from the National Science Foundation, followed by a contract from
DARPA.The papers published after this research also mark the first appearance of the
expression brain–computer interface in scientific literature.
The field of BCI research and development has since focused primarily on neuroprosthetics
applications that aim at restoring damaged hearing, sight and movement. Thanks to the
remarkable cortical plasticity of the brain, signals from implanted prostheses can, after
adaptation, be handled by the brain like natural sensor or effector channels. Following years
of animal experimentation, the first neuroprosthetic devices implanted in humans appeared in
the mid-1990s.
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2. WORKING:
Operation of the BCI system is not simply listening the EEG of user in a way that let’s tap
this EEG in and listen what happens. The user usually generates some sort of mental activity
pattern that is later detected and classified.
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 :
.
DETECTION:
The detection of the input from the user and them translating it into an action could be
considered as key part of any BCI system. This 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.
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 e.g. when typing
with virtual keyboard, letter appears to the message box etc.
TRAINING:
The training is the part where the user adapts to the BCI system. This training begins with
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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
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.
A boon to the paralyzed –Brain Gate Neural Interface System
The first patient, Matthew Nagle, a 25-year-old Massachusetts man with a severe spinal cord
injury, has been paralyzed from the neck down since 2001. Nagle is unable to move his arms
and legs after he was stabbed in the neck. During 57 sessions, at New England Sinai Hospital
and Rehabilitation Center, Nagle learned to open simulated e-mail, draw circular shapes
using a paint program on the computer and play a simple videogame, "neural Pong," using
only his thoughts. He could change the channel and adjust the volume on a television, even
while conversing. He was ultimately able to open and close the fingers of a prosthetic hand
and use a robotic limb to grasp and move objects. Despite a decline in neural signals after few
months, Nagle remained an active participant in the trial and continued to aid the clinical
team
in
producing
valuable
feedback
concerning
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the
BrainGate`
technology.
Brain Gate Technology
Fig 7. Mathew Nagle
NAGLE’S STATEMENT:
“I can't put it into words. It's just—I use my brain. I just thought it. I said, "Cursor go up to the top right." And it
did, and now I can control it all over the screen. It will give me a sense of independence.”
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3. APPLICATIONS:

In classification of EEG signal.

In multimedia communication.

In evaluation of spike detection algorithms.

Actuated control of mobile robot by human EEG.

As a brain controlled switch for asynchronous control.

In evaluating the machine learning algorithms.
Fig 8. Applications
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4. CASE STUDY:
The robotic arm clutched a glass and swung it over a series of coloured dots that
resembled a Twister gameboard. Behind it, a woman sat entirely immobile in a
wheelchair. Slowly, the arm put the glass down, narrowly missing one of the dots. "She's
doing that!" exclaims Professor John Donoghue, watching a video of the scene on his
office computer – though the woman onscreen had not moved at all. "She actually has the
arm under her control," he says, beaming with pride. "We told her to put the glass down
on that dot."
The woman, who is almost completely paralysed, was using Donoghue's groundbreaking
technology to control the robot arm using only her thoughts. Called BrainGate, the device
is implanted into her brain and hooked up to a computer to which she sends mental
commands. The video played on, giving Donoghue, a silver-haired and neatly bearded
man of 62, even more reason to feel pleased. The patient was not satisfied with her near
miss and the robot arm lifted the glass again. After a brief hover, the arm positioned the
glass on the dot.
Fig 9. The Brain Sensor
The tiny BrainGate sensor. Photograph: Chitose Suzuki/AP This is the remarkable world
of the brain-computer interface, or BCI, of which BrainGate is one of the leading devices
and Donoghue one of its most successful pioneers. It is a branch of science exploring how
computers and the human brain can be meshed together. It sounds like science fiction
(and can look like it too), but it is motivated by a desire to help chronically injured
people. They include those who have lost limbs, people with Lou Gehrig's disease, or
those who have been paralysed by severe spinal-cord injuries. But the group of people it
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might help the most are those whom medicine assumed were beyond all hope: sufferers of
"locked-in syndrome". These are often stroke victims whose perfectly healthy minds end
up trapped inside bodies that can no longer move. The most famous example was French
magazine editor Jean-Dominique Bauby who managed to dictate a memoir, The Diving
Bell and the Butterfly, by blinking one eye. In the book, Bauby, who died in 1997 shortly
after the book was published, described the prison his body had become for a mind that
still worked normally.Donoghue believes that BrainGate would have opened Bauby's
prison door, even if just a little. "I would have every expectation that if we had put
BrainGate in his brain, it would have immediately started giving us signals," Donoghue
says. Donoghue and his team have devoted years of research to BrainGate, first
successfully testing the technology on monkeys and then moving to a groundbreaking set
of clinical trials using human subjects. Now the project is involved with a second set of
human trials, pushing the technology to see how far it goes and trying to miniaturise it
and make it wireless for a better fit in the brain. BrainGate's concept is simple. It posits
that the problem for most patients does not lie in the parts of the brain that control
movement, but with the fact that the pathways connecting the brain to the rest of the
body, such as the spinal cord, have been broken. BrainGate plugs into the brain, picks up
the right neural signals and beams them into a computer where they are translated into
moving a cursor or controlling a computer keyboard. By this means, paralysed people can
move a robot arm or drive their own wheelchair, just by thinking about it.In his book
Bauby called his immobilised body a diving bell and his mind a butterfly trapped inside.
He described his sadness at being unable to talk back when his loved ones spoke to him
on the phone. "How dearly I would love to be able to respond with something other than
silence to those tender calls," he wrote. The woman on the video that Donoghue just
played has almost the exact same condition Bauby had. Now she is able to talk to
Donoghue over the internet, moving a cursor over a keyboard with her mind and
communicating much faster than Bauby did.
Donoghue works from inside a rambling old mansion perched on top of a hill. But the
offices of the Brown Institute for Brain Science are not really the stuff of old horror
movies. The pleasant-looking building is part of Brown University in the pretty college
town of Providence, Rhode Island, on the New England coast.
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It is here that he and his team are decoding the language of the human brain. This
language is made up of electronic signals fired by billions of neurons and it controls
everything from our ability to move, to think, to remember and even our consciousness
itself. Donoghue's genius was to develop a deceptively small device that can tap directly
into the brain and pick up those signals for a computer to translate them. Gold wires are
implanted into the brain's tissue at the motor cortex, which controls movement. Those
wires feed back to a tiny array – an information storage device – attached to a "pedestal"
in the skull. Another wire feeds from the array into a computer. A test subject with
BrainGate looks like they have a large plug coming out the top of their heads. Or, as
Donoghue's son once described it, they resemble the "human batteries" in The Matrix.
BrainGate's highly advanced computer programs are able to decode the neuron signals
picked up by the wires and translate them into the subject's desired movement. In crude
terms, it is a form of mind-reading based on the idea that thinking about moving a cursor
to the right will generate detectably different brain signals than thinking about moving it
to the left.
The technology has developed rapidly, and last month BrainGate passed a vital milestone
when one paralysed patient went past 1,000 days with the implant still in her brain and
allowing her to move a computer cursor with her thoughts. The achievement, reported in
the prestigious Journal of Neural Engineering, showed that the technology can continue to
work inside the human body for unprecedented amounts of time.
Donoghue talks enthusiastically of one day hooking up BrainGate to a system of
electronic stimulators plugged into the muscles of the arm or legs. That would open up
the prospect of patients moving not just a cursor or their wheelchair, but their own bodies.
"We are working on a system where there is a stimulator in another part of the body wired
to the muscle, and when it's activated you can get opening and closing of the hand and
movement of the arm."
The late Matt Nagle, who first tested the BrainGate device. He was paralysed by a spinal
cord injury. Photograph: Rick Friedman It is a remarkable idea with humble beginnings.
The first BrainGate patient, a quadraplegic called Matthew Nagle, was plugged into a
computer in 2004. Nagle, a keen young sports fan, had been stabbed while trying to help
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a friend in a fight. The blade had severed his spinal cord. Donoghue had no idea if Nagle's
motor cortex would still be able to send the right signals for movement. "The big moment
was when we first turned on the recording electrode so we could peer into the brain.
Except for brief moments in the operating room, we never had the opportunity to do that
in humans," Donoghue says of BrainGate's big breakthrough moment. It was tense. If
Nagle's motor cortex was no longer working healthily, the entire BrainGate project could
have been rendered pointless. But when Nagle was plugged in and asked to imagine
moving his limbs, the signals beamed out with a healthy crackle. "We asked him to
imagine moving his arm to the left and to the right and we could hear the activity,"
Donoghue says. When Nagle first moved a cursor on a screen using only his thoughts, he
exclaimed: "Holy shit!"
Nagle rapidly became a poster boy for BrainGate, eventually learning to play simple
computer games, operate a TV and send and receive emails. Sadly, he died in 2007 of an
infection. "It was awful. Just awful when Matt died. We were all very much attached,"
Donoghue says. "I am trying to make people who are in a terrible state have a much better
life. Right now, anything that we can do for them is a huge improvement." That is no
doubt true. But BrainGate and other BCI projects have also piqued the interest of the
government and the military. BCI is melding man and machine like no other sector of
medicine or science and there are concerns about some of the implications. First, beyond
detecting and translating simple movement commands, BrainGate may one day pave the
way for mind-reading. A device to probe the innermost thoughts of captured prisoners or
dissidents would prove very attractive to some future military or intelligence service.
Second, there is the idea that BrainGate or other BCI technologies could pave the way for
robot warriors controlled by distant humans using only their minds. At a conference in
2002, a senior American defence official, Anthony Tether, enthused over BCI. "Imagine a
warrior with the intellect of a human and the immortality of a machine." Anyone who has
seen Terminator might worry about that. Donoghue acknowledges the concerns but has
little time for them. When it comes to mind-reading, current BrainGate technology has
enough trouble with translating commands for making a fist, let alone probing anyone's
mental secrets. "There are unrealistic fears. So I am not too worried that we are going to
tap into your brain," he says.
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As for robot warriors, Donoghue was slightly more circumspect. At the moment most
BCI research, including BrainGate projects, that touch on the military is focused on
working with prosthetic limbs for veterans who have lost arms and legs. But Donoghue
thinks it is healthy for scientists to be aware of future issues. "As long as there is a
rational dialogue and scientists think about where this is going and what is the reasonable
use of the technology, then we are on a good path," he says.
Donoghue comes across as a pragmatic and careful scientist. Perhaps that comes from his
humble background as the son of a working-class Boston Irish bricklayer father and a
housewife mother. Or from an academic career spent almost entirely in the same
institution. But he does allow himself to dream, just a little, of where BrainGate's
technology might go one day. His team are already working on a miniaturised and
wireless version. Although it has not been implanted in a human yet, that new version of
BrainGate will remove the need for a "plug" in the skull and could allow patients to be
permanently hooked up. The prototype looks like a large, flattened memory stick and will
go inside the head. It would communicate wirelessly with a computer worn on a belt. So
no wonder Donoghue can dream of a future where BrainGate and other devices can
restore full mobility to those from whom physical movement has been stolen. "The really
way-off treatment, which I will never see, is that we connect BrainGate, maybe four
arrays in the two leg and two arm areas of the brain, and put it out to all the muscles with
stimulators and then the subject is playing basketball or something," he says. "There is no
reason why with enough knowledge and enough time that we couldn't do that." It will not
be soon though; almost certainly not in Donoghue's lifetime. "One hundred years from
now, when people are walking around with an artificial nervous system made of wires
and chips, people will say, 'I bet they didn't imagine this.'"
One person who did think about it was Bauby. At the end of The Diving Bell and the
Butterfly he dreams of one day being let out of his prison. "Does the cosmos contain keys
for opening up my diving bell? A subway line with no terminus? A currency strong
enough to buy my freedom back? We must keep looking." Bauby died before there was
much hope for that. Others similarly stricken in the future may be luckier.
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5. FUTURE SCOPE:

Enable individuals with paralysis to use e-mail and telephones to communicate.

Provide access to environmental controls, such as bed positioning, television, lights,

and thermostats through a desktop application.

Improve mobility by interfacing with powered wheelchairs.

Provide patients with the ability to adjust their body position to avoid pressure sores.

Facilitate control over all of these actions and a range of other software and

external device applications through a single, universal integrated interface
Cyberkinetics has a vision, CEO Tim Surgenor 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.
"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. Then it is possible to use the computer to control a robot arm or their own arm, but that
would be down the road."
Existing technology stimulates muscle groups that can make an arm move. The problem
Surgenor and his team faced was in creating an input or control signal. With the right control
signal they found they could stimulate the right muscle groups to make arm movement.
"Another application would be for somebody to handle a tricycle or exercise machine to help
patients who have a lot of trouble with their skeletal muscles. But walking, I have to say,
would be very complex. There's a lot of issues with balance and that's not going to be an easy
thing to do, but it is a goal."Cyberkinetics hopes to refine the BrainGate in the next two years
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to develop a wireless device that is completely implantable and doesn't have a plug, making it
safer and less visible. And once the basics of brain mapping are worked out there is potential
for a wide variety of further applications, Surgenor explains.
"If you could detect or predict the onset of epilepsy, that would be a huge therapeutic
application for people who have seizures, which leads to the idea of a 'pacemaker for the
brain'. So eventually people may have this technology in their brains and if something starts
to go wrong it will take a therapeutic action. That could be available by 2007 to 2008."
Surgenor also sees a time not too far off where normal humans are interfacing with BrainGate
technology to enhance their relationship with the digital world - if they're willing to be
implanted."If we can figure out how to make this device cheaper, there might be applications
for people to control machines, write software or perform intensive actions. But that's a good
distance away. Right now the only way to get that level of detail from these signals is to
actually have surgery to place this on the surface of the brain. It's not possible to do this with
a non-invasive approach. For example, you can have an EEG and if you concentrate really
hard you can think about and move a cursor on a screen, but if someone makes a loud noise
or you get interrupted, you lose that ability. What we're trying to make here is a direct
connection. The [BrainGate] is going to be right there and you won't have to think about it."
DARPA
The Brown University group was partially funded by the Defence Advanced Research
Projects Agency (DARPA), the central research and development organisation for the US
Department of Defence (DoD). DARPA has been interested in Brain-Machine-Interfaces
(BMI) for a number of years for military applications like wiring fighter pilots directly to
their planes to allow autonomous flight from the safety of the ground. Future developments
are also envisaged in which humans could 'download' memory implants for skill
enhancement, allowing actions to be performed that have not been learned directly.
Surgenor discounts the near term possibility of this type of 'memory enhancement', however,
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saying several critical factors would have to be overcome.
"I don't know about memory but I do think that it will be possible to augment sense.
Instantaneous sensation will be possible. In order to do memory we'd have to figure out how
the brain actually stores that information, which is not well understood at this point.
"You can learn to interpret an electrical stimulation pattern in your ear and turn that into
sound. So that's a sensation. Some companies are interested in connecting television cameras
to the retina of the eye, and there's other groups - academics, not companies - that are
interested in putting a connector directly to the part of the brain that processes vision. Those
are the cortical applications envisaged at the moment - vision and hearing."
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6. CONCLUSION
The idea of moving robots or prosthetic devices not by manual control, but by mere
“thinking” (i.e., the brain activity of human subjects) has been a fascinated approach. Medical
cures are unavailable for many forms of neural and muscular paralysis. The enormity of the
deficits caused by paralysis is a strong motivation to pursue BMI solutions. So this idea helps
many patients to control the prosthetic devices of their own by simply thinking about the task.
This technology is well supported by the latest fields of Biomedical Instrumentation,
Microelectronics, signal processing, Artificial Neural Networks and Robotics which has
overwhelming developments. Hope these systems will be effectively implemented for many
Biomedical applications.
 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.
 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 .
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7. BIBLIOGRAPHY
7.1 Book

How the Brain Is Shaping the Future of the Internet
7.2 Websites

www.cyberkineticsinc.com,

http://www.wired.com/news/medtech/0,1286,66259,00.html

http://www.youtube.com/watch?v=VLymwjTMC_Y

www.howstuffworks.com
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