BrainGate Systems Report

7/27/2019 BrainGate Systems Report

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1. INTRODUCTIONBrainGate 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.

Cyber kinetics describes that, "Such applications may include novel

communications interfaces for motor impaired patients, as well as the monitoring andtreatment of certain diseases which manifest themselves in patterns of brain activity,

such as epilepsy and depression."

According to the Cyber kinetics' website, three patients have been implanted with

the Brain Gate system. The company has confirmed that one patient (Matt Nagle) has a

spinal cord injury, while another has advanced ALS.

The remarkable breakthrough offers hope that people who are paralyzed will oneday be able to independently operate artificial limbs, computers or wheelchairs. The

implant, called Brain Gate, allowed Matthew Nagle, a 25-year-old Massachusetts man

who has been paralyzed from the neck down since 2001, to control a cursor on a

screen and to open and close the hand on a prosthetic limb just by thinking about the

relevant actions. Professor Donoghue's work is published today in Nature. He

describes how, after a few minutes spent calibrating the implant, Mr. Nagle could read

emails and play the computer game Pong. He was able to draw circular shapes using a

paint program and could also change channel and turn up the volume on a television,

even while talking to people around him. After several months, he could also operate

simple robotic devices such as a prosthetic hand, which he used to grasp and move

objects 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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Fig. 1.1 Mathew Nagle using Brain Gate

Nagles Statement:

I can't put it into words. It's justI 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.

In addition to real-time analysis of neuron patterns to relay movement, the Brain

gate 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. The 'BrainGate' device can provide paralyzed or motor-impaired patients a

mode of communication through the translation of thought into direct computer

control. The technology driving this breakthrough in the Brain-Machine-Interface field

has a myriad of potential applications, including the development of human

augmentation for military and commercial purposes.

The Brain Fate Neural Interface device consists of a tiny chip containing 100

microscopic electrodes that is surgically implanted in the brain's motor cortex. This

tiny chip contains tiny spikes that will extend down about one millimeter into the brain

after being implanted beneath the skull, monitoring the activity from a small group of

neurons. The chip can read signals from the motor cortex, send that information to a


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computer via connected wires, and translate it to control the movement of a computer

cursor or a robotic arm. 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. The

whole apparatus is the size of a baby aspirin.

According to Dr. John Donaghue of Cyber kinetics, there is practically no training

required to use Brain Gate because the signals read by a chip implanted, for example,

in the area of the motor cortex for arm movement, are the same signals that would be

sent to the real arm. A user with an implanted chip can immediately begin to move a

cursor with thought alone. However, because movement carries a variety of

information such as velocity, direction, and acceleration, there are many neurons

involved in controlling that movement. Brain Gate is only reading signals from an

extremely small sample of those cells and, therefore, only receiving a fraction of the

instructions. Without all of the information, the initial control of a robotic hand may

not be as smooth as the natural movement of a real hand. But with practice, the user

can refine those movements using signals from only that sample of cells.

Brain gate is currently recruiting patients with a range of neuromuscular and

neurodegenerative conditions for pilot clinical trials in the United States. Cyber

kinetics hopes to refine the Brain Gate in the next two years 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. Surgeon explains, "If you could detect or predict

the onset of epilepsy, which would be a huge therapeutic application for people who

have seizures, which leads to the idea of a 'Pacemaker for the Brain'. They have built a

wireless implantable microelectronic device for transmitting cortical signals

transcutaneously. The device is aimed at interfacing a microelectrode array cortical to

an external computer for neural control applications. The implantable microsystem

enables presently 16-channel broadband neural recording in a non-human primate

brain by converting these signals to a digital stream of infrared light pulses for

transmission through the skin. So eventually people may have this technology in their

brains and if something starts to go wrong it will take a therapeutic action.


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2. WHAT IS BRAINGATE SYSTEMS?2.1 Neural Interface System Device:

The Brain Gate Neural Interface System is currently the subject of a pilot clinical

trial being conducted under an Investigational Device Exemption (IDE) from the FDA.

The system is designed to restore functionality for a limited, immobile group of

severely motor-impaired individuals. It is expected that people using the Brain Gate

System will employ a personal computer as the gateway to a range of self-directed

activities. These activities may extend beyond typical computer functions (e.g.,

communication) to include the control of objects in the environment such as a

telephone, a television and lights.

The Brain Gate Neural Interface Device is a proprietary brain computer interface

that uses an internal sensor to detect brain activity and external processors that convert

these brain signals into a computer-mediated output under the persons own control.

The Brain Gate System is a hardware device that uses software. The sensor consists of

a tiny chip, smaller than a baby aspirin, which contains one hundred electrode sensors

that each tap into a separate neuron. Brain Gate senses, analyses, and transmits the

data from the brain to an outside system. This allows the user to interact with the

outside world in a more independent way. The ultimate goal of the Brain Gate System

development program is to create a safe, effective and unobtrusive universal operating

system that will enable those with motor impairments to control a wide range of

devices, including computers, assistive technologies and medical devices, by simply

using their thoughts.

Brain Gate contains a chip that is implanted on the surface of the motor cortex area

of the brain. In the pilot version of the device, a cable connects the sensor to an

external signal processor in a cart that contains three computers. The computers

translate hard-to detect brain signals to create the communication output using custom

decoding software. When the patient is connected to the system he or she can mentally

move the cursor just like a mouse would do. John Donoghue, the chair of the

Department of Neuroscience at Brown University, led the original project research and

went on to co-found Cyber kinetics, where he is currently chief scientific officer


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overseeing the clinical trial. Hugh Herr, another scientist, also helped in the

development of a neural interface system. Herr became very passionate about the

development of a technology that would give independence and movement back to

people that were physically impaired. Herr lost both legs at a young age from frostbite.

He then started research on combining both body and machine, his research has

already made a significant impact for people that are physically challenged. He has

helped in the development of many prosthetics.

The development of the Brain Gate System brain-computer interface is to

enable those with severe paralysis and other neurological conditions to live more

productively and independently. Also, scientists are developing the Brain Gate

Systems underlying core technology in the NeuroPort System to enable improved

diagnosis and treatment for a number of neurological conditions, such as epilepsy and

brain trauma. The NeuroPort System is a neural monitor designed for acute inpatient

applications and labeled for temporary recording and monitoring of brain electrical

activity. Brain Gate will be the first human device that has been designed to record,

filter, and amplify multiple channels of simultaneously recorded neural activity at a

very high spatial and temporal resolution. It has been thoroughly researched and will

contribute to the diagnosis and treatment of neurological conditions in patients whohave undergone a craniotomy. This will give neurologists and neurosurgeons a new

resource to detect, transmit and analyze neural activity.

Fig 2.1 Brain Gate Technology


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Dr. Steve Williams, a clinical advisor to Cyber kinetics, presented a description of

the Brain Gate Controller, a next generation, standardized interface system that is

under development. The development of this system would replace the initial

prototype controller which has been used in the Brain Gate trial until now. The

M*Power Controller is designed to allow a Brain Gate System patient to control a

standard wireless computer device. The new interface is also intended to be easier to

use for patients and their families, so they can access the capabilities of the system on

a routine basis without reliance on a technician. These two closely linked efforts are

intended to yield a Brain Gate System allowing patients significant control over their

environment, the ability to readily perform numerous daily activities that are currently

beyond their reach, and vastly enhance communications opportunities. For example,

use of the M*Controller as an interface control, by thought alone would allow patients

to perform a range of tasks including: making and receiving telephone calls,

controlling remote devices, accessing the internet, and communicating via e-mail.

The Brain Gate system includes hardware and software and may be used as a

telecommunication device in the future. This could greatly impact a business or

organization. It will give people with disabilities a chance to work at a business just

like anyone else. With this technology they will be able use a wide variety of devicesand may also lead to a decline in the use of hands on activities. With the development

of devices such as these, one day everyone may have chips in their brain that will

allow them to perform tasks without the use of their body.

Here is a recap of the main points:

Brain Gate is a neural interface system device that has a chip that reads brainactivity through the use of sensors and then transmits the activities to threecomputers which convert the thoughts into actions.

This system is used for people that are physically impaired; it helps give themthe independence and the capabilities of the norm. The scientists working on

Brain Gate hope to create an operating system that is safe, effective and

unobtrusive. The neurologists are constantly trying to come up with more ideas

to push this form of emerging technology further.


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2.2 History:

After 10 years of study and research, Cyber kinetics, a biotech company in

Foxboro, Massachusetts, has developed Brain Gate in 2003. Dr. John Donaghue,

director of the brain science program at Brown University, Rhode Island, and chief

scientific officer of Cyber kinetics, the company behind the brain implant, lead the

team to research and develop this brain implant system. He studied the functioning of

Brain gate in monkeys and proved that they were able to control a cursor on a

computer monitor with their thoughts. They have not only demonstrated in preclinical

studies that brain gate can remain safely implanted in the (monkey) brain for at least

two years, but have shown that it can safely be removed as well.

2.3 About the BrainGate Device:

The Brain gate pilot device consists of a Sensor of the size of a contact lens, a cable

and pedestal, which connects the chip to the computer, a cart which consists of the

signal processing unit.

Fig. 2.1(a) BrainGate Cable Assembly

Fig.2.2 BrainGate Cart

Fig. 2.1(b) BrainGate Cable Assembly


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2.4 The Neuro-Chip:

The chip, about the size of a baby

aspirin, contains 100 electrode sensors, eachthinner than a human hair. The sensors detect

tiny electrical signals generated when a user

imagines. The activity is translated into

electrically charged signals and is then sent

and decoded using a program, which can move

either a robotic arm or a computer cursor.

Though paralyzed, a quadriplegic still has theability to generate such signals -- they just don't get past the damaged portion of the

spinal cord. With BrainGate, the signals instead travel through a wire that comes out of

the skull and connects to a computer.

The Utah array has become a benchmark for multi-

channel, high-density neural recordings and

stimulation applications from large populations of

neurons. Over the past two decades, this patented

micro electrode array technology has undergone

numerous refinements and repeated validations in a variety of species and

preparations. This effort delivered a proven and well-documented method to obtain

stable and long-term neural recordings of action potentials (spikes) and field potentials

in brain and peripheral-nerve tissue.

In addition to real-time analysis of neuron patterns to relay movement, the Brain

gate 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.


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3. BCI TECHNOLOGY

Brain computer interfaces determine the intent of the user from a variety of

different electrophysiological signals which include slow cortical potentials, P300

potentials or beta rhythms recorded from the scalp.

Fig 3.1 BCI Working

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. The common thread throughout the research is

the remarkable cortical plasticity of the brain, which often adapts to BCIs, treating

prostheses controlled by implants as natural limbs. 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

the realm of science fiction.


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3.1BCI V/S Neuroprosthetics:Neuroprosthetics is an area of neuroscience concerned with neural prostheses

using artificial devices to replace the function of impaired nervous systems or sensory

organs. The most widely used neuroprosthetic device is the cochlear implant, which

was implanted in approximately 100,000 people worldwide as of 2006. There are also

several neuroprosthetic devices that aim to restore vision, including retinal implants,

although this article only discusses implants directly into the brain.

The differences between BCIs and neuroprosthetics are mostly in the ways the

terms are used: neuroprosthetics typically connect the nervous system, to a device,

whereas the term BCIs usually connects the brain (or nervous system) with a

computer system. Practical neuroprosthetics can be linked to any part of the nervous

system, for example peripheral nerves, while the term "BCI" usually designates a

narrower class of systems which interface with the central nervous system.

The terms are sometimes used interchangeably and for good reason.

Neuroprosthetics and BCI seek to achieve the same aims, such as restoring sight,

hearing, movement, ability to communicate, and even cognitive function. Both use

similar experimental methods and surgical techniques.

Based on the communicative Pathway BCI is classified as follows:

One way BCI: Computers either accept commands from the brain or sendsignals to it (for example, to restore vision) but not both.

Two ways BCI: Brains and external devices can exchange information in bothdirections but have yet to be successfully implanted in animals or humans.


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4. IMPLEMENTATION OF BRAIN GATE

4.1 Principle:

"The principle of operation of the Brain Gate 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 "Brain Gate

pathway". The user can use that cursor to control the computer, just as a mouse is

used."

4.2How does the brain control motor function?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 acomputer, 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 interneuron tie everything together by connecting the various

neurons within the brain and spinal cord. The part of the brain that controls motor

skills is located at the ear of the frontal lobe.


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4.3Neuron:A Neuron is an electrically excitable cell that processes and transmits information

through electrical and chemical signals. A chemical signal occurs via a synapse, a

specialized connection with other cells. Neurons connect to each other to form neural

networks. Neurons are the core

components of the nervous

system, which includes

the brain, spinal cord, and

peripheral ganglia. A number of

specialized types of neurons

exist: sensory neurons respond

to touch, sound, light and

numerous other stimuli affecting cells of the sensory organs that then send signals to

the spinal cord and brain. Motor neurons receive signals from the brain and spinal

cord, cause muscle contractions, and affect glands. Inter neurons connect neurons to

other neurons within the same region of the brain or spinal cord.

4.4 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 translatebrain 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.
http://en.wikipedia.org/wiki/Electricityhttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Synapsehttp://en.wikipedia.org/wiki/Neural_networkhttp://en.wikipedia.org/wiki/Neural_networkhttp://en.wikipedia.org/wiki/Nervous_systemhttp://en.wikipedia.org/wiki/Nervous_systemhttp://en.wikipedia.org/wiki/Brainhttp://en.wikipedia.org/wiki/Spinal_cordhttp://en.wikipedia.org/wiki/Gangliahttp://en.wikipedia.org/wiki/Sensory_neuronhttp://en.wikipedia.org/wiki/Sensehttp://en.wikipedia.org/wiki/Motor_neuronhttp://en.wikipedia.org/wiki/Muscle_contractionhttp://en.wikipedia.org/wiki/Glandhttp://en.wikipedia.org/wiki/Interneuronhttp://en.wikipedia.org/wiki/Interneuronhttp://en.wikipedia.org/wiki/Glandhttp://en.wikipedia.org/wiki/Muscle_contractionhttp://en.wikipedia.org/wiki/Motor_neuronhttp://en.wikipedia.org/wiki/Sensehttp://en.wikipedia.org/wiki/Sensory_neuronhttp://en.wikipedia.org/wiki/Gangliahttp://en.wikipedia.org/wiki/Spinal_cordhttp://en.wikipedia.org/wiki/Brainhttp://en.wikipedia.org/wiki/Nervous_systemhttp://en.wikipedia.org/wiki/Nervous_systemhttp://en.wikipedia.org/wiki/Neural_networkhttp://en.wikipedia.org/wiki/Neural_networkhttp://en.wikipedia.org/wiki/Synapsehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Electricity


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5. WORKING

Operation of the BCI system is not simply listening the EEG of user in a way that

lets tap this EEG in and listen what happens. The user usually generates some sort of

mental activity pattern that is later detected and classified.

5.1 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.

Fig. 5.1 Brain Computer Interface I

5.2Detection: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


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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.

5.3 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.

Fig. 5.2 Brain Computer Interface II

5.4 Software Used:

Software is necessary for transmission of the signals from the chip implanted on the

brain to the machine and for decoding these signals and to convert it to corresponding

action by the machine.


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The computers translate brain activity and create the communication output using

custom decoding software and the algorithms are written in languages like C, Java and

MATLAB. The software is a BCI based on trials which is a time interval where the

user generates brainwaves to perform an action. The signals are processed and

associated to a given class and is done by feeding a neural net with the preprocessed

EEG data. Further the neural nets output is processed and this final output

corresponds to the given class. The software has three operating modes and they are

Simulation, Recording and Training.

5.4.1 Simulation & Recording:The simulationmode is used to test the BCI. Recordingis the same as simulation,

with the difference that the EEG data is recorded and used as training examples. It

further has 3 operations within and they are Preparation, Prerecording and Recording.

5.4.2 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.

5.5 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.

5.6 Platform Technology:Neurons are cells that use a language of electrical impulses to communicate

messages from the brain to the rest of the body. At Cyber kinetics, we have the

technology to sense, transmit, analyze and apply the language of neurons. We are


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developing products to restore function, as well as to monitor, detect, and respond to a

variety of neurological diseases and disorders.

Cyber kinetics offers a systems approach with a core technology to sense, transmit,

analyze and apply the language of neurons in both short and long-term settings. Our

platform technology is based on the results of several years of research and

development at premier academic institutions such as Brown University, the

Massachusetts Institute of Technology, Emory University, and the University of Utah.

5.7 Sense:Cyberkinetics unique technology is able to simultaneously sense the electrical

activity of many individual neurons. Our sensor consists of a silicon array about the

size of a baby aspirin that contains one hundred electrodes, each thinner than a human

hair. The array is implanted on the surface of the brain. In the Brain Gate Neural

Interface System, the array is implanted in the area of the brain responsible for limb

movement. In other applications the array may be implanted in areas of the brain

responsible for other body processes.

5.8 Transmit And Analysis:The human brain is a super computer with the ability to instantaneously process

vast amounts of information. Cyberkinetics 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 Brain Gate 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.

5.9 Apply:Cyber kinetics ability to generate control signals and develop computer application

interfaces provides us with a platform to develop multiple clinical products. For

example, using the Brain Gate Neural Interface System, a person may be able to use


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his thoughts to control cursor motion and/or replicate keystrokes on a computer screen.

In another example, a doctor may study patterns of brain electrical activity in patients

with epilepsy before, during and after seizures.

5.10Implanting The Chip:There will be two surgeries, one to implant the Brain Gate and one to remove it.

Before surgery, there will be several precautionary measures in order to prevent

infection; patients will have daily baths with antimicrobial soap and take antibiotics. In

addition, MRI scans will be done to find the best place on the brain for the sensor.

Under sterile conditions and general anesthesia, Doctor will drill a small hole into the

skull and implant the sensor using the same methods as in the monkey studies. Patients

will receive post-surgical care including a CT scan, some blood tests, and wound care

in the hospital for 1 to 5 days after surgery. After surgery, one of the study doctors will

see the patients at least once a week for six weeks, then monthly and as needed. A

nurse will also check the patients regularly and will always carry a 24-hour pager. The

skin around the pedestal will need to be carefully monitored during the study. Detailed

instructions will be provided so that the patients daily care provider can help with skin

care.


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The sensor of the size of a contact lens is implanted in brains percental gyrus

which control hand and arm movements. A tiny wire connects the chip to a small

pedestal secured in the scull. A cable connects the pedestal to a computer. The brain's

100bn neurons fire between 20 and 200 times a second .The sensor implanted in the

brain senses these electrical signals and passes to the pedestal through the wire. The

pedestal passes these signals to the computer through the cable. The computer

translates the signals into a communication output, allowing a person to move a cursor

on a computer screen merely by thinking about it.


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6. BRAIN GATE RESEARCH IN ANIMALS

Rats implanted with BCIs in Theodore Berger's experiments. Several laboratories

have managed to record signals from 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.

Fig 6.1 Brain Gate Research in Animals

Garrett Stanley's recordings of cat vision using a BCI implanted in the lateral

geniculation 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 geniculation 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.

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,
http://en.wikipedia.org/wiki/Image:MouseBCI.jpg


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including research groups led by Richard Andersen, John Donoghue, Phillip Kennedy,

Miguel Nicolelis, and Andrew Schwartz.

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.

6.1 Wireless Recording for Neuroprosthetic Application:

They have built a wireless implantable microelectronic device for transmitting

cortical signals transcutaneously. The device is aimed at interfacing a microelectrode

array cortical to an external

computer for neural control

applications. Our implantable

microsystem enables presently

16-channel broadband neural

recording in a non-human

primate brain by converting

these signals to a digital stream

of infrared light pulses for

transmission through the skin. The implantable unit employs a flexible polymer

substrate onto which we have integrated ultra-low power amplification with analog

multiplexing, an analog-to-digital converter, a low power digital controller chip, and

infrared telemetry. The scalable 16-channel microsystem can employ any of several

modalities of power supply, including via radio frequency by induction, or infrared

light via a photovoltaic converter. As of today, the implant has been tested as a sub-

chronic unit in non-human primates (~ 1 month), yielding robust spike and broadband

neural data on all available channels.


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7. APPLICATIONS OF BRAIN GATE

Multi Device Patient Ambulation SystemA sensor with a number of electrodes for detecting multi cellular signals, a

processing unit configured to receive the multi cellular signals and produce aprocessed signal, and transmit the processed signal to a controlled device. This

helps the patient in achieving movement.

Biological Interface System With Patient Training ApparatusThe system includes a patient training apparatus configured to receive a

patient training signal that causes the patient training apparatus to controllably

move one or more joints of the patient.

Biological Interface System With Surrogate Controlled DeviceMulti cellular signals emanating from one or more living cells of a patient,

and a processing unit configured to receive the multi cellular signals from the

sensor and process the multi cellular signals to produce a processed signal. The

processing unit may be configured to transmit the processed signal to a

controlled device.

Limb And Digit Movement System:Data from the joint movement device is transmitted to the processing unit

for determining a value of a configuration parameter of the system and

controlled cables that produce the forces required.

DARPADARPA has been interested in Brain-Machine-Interfaces (BMI) for military

applications like wiring fighter pilots directly to their planes to allow

autonomous flight from the safety of the ground.

Mental TypewriterThis application demonstrates how a paralyzed patient could communicate

by using a mental typewriter alone without touching the keyboard.


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8. COMPETITIVE ADVANTAGES AND DISADVANTAGES

8.1 Advantages:

The BrainGate Neural Interface System is being designed to one day allow the user

to interface with a computer and/or other devices at a level of speed, accuracy and

precision that is comparable to, or even faster than, what is possible with the hands of

a non-disabled person.

The Brain Gate System may offer substantial improvement over existing assistive

technologies. Currently available assistive devices have significant limitations for both

the person in need and the caregiver. For example, even simple switches must be

adjusted frequently, a process that can be time consuming. In addition, these devices

are often obtrusive and may prevent the user from being able to simultaneously use the

device and at the same time establish eye contact or carry on conversations with

others. Potential advantages of the Brain Gate System over other muscle driven or

brain-based computer interface approaches include: its potential to interface with a

computer without weeks or months of training; its potential to be used in an interactive

environment, where the user's ability to operate the device is not affected by their

speech, eye movements or ambient noise; and the ability to provide significantly moreusefulness and utility than other approaches by connecting directly to the part of the

brain that controls hand movement and gestures.

8.2 With a BrainGate we can:

Turn on/off the lights on your room Check and read E-mails Play games in computer Use your PC Watch and control your Television Control a robotic arm

Fig 8.1 Advatages of BrainGate


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8.3Disadvantages: The disadvantage of the Brain Gate System is that at this time, while still being

perfected, the switches must be frequently adjusted which is a time consuming

process. As the device is perfected this will not be an issue. There is also a

worry that devices such as this will normalize society. The Brain Gate Neural

Interface System has not been approved by the FDA, but has been approved for

IDE status, which means that it has been approved for pre-market clinical

trials. There are no estimates on cost or insurance at this time.

Difficulty in adaptation and learning. Limitation in information transform rate. The latest technology is 20 bits/min.


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9. FUTURE ENHANCEMENTS Future Brain Gate system products may control devices that allow breathing,

bladder and bowel movements.

Development of second generation patient interface software that will enableusers to perform a wide variety of daily activities without the assistance of the

technician.

Development of a Brain Gate system which has a wireless interface betweenthe implanted server and the computer.

9.1 Future of Neural Interfaces:

BrainGate-Turning Thought into Action has a vision, The CEO 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 paralyzed people and to provide a platform for the

development of a wide range of other assistive devices. BrainGate hopes to refine the

BrainGate in the next two years to develop a wireless device that is completely

implantable and doesn't have a plug, making it safer and less visible. Surgeon also sees

a time not too far off where normal humans are interfacing with BrainGate technologyto enhance their relationship with the digital world - if they're willing to be implanted.

Scientists have for the first time developed a brain implant that allows people to

control electronic devices by thought alone.


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9. CONCLUSION

The invention of Brain gate is such a revolution in medical field. The remarkable

breakthrough offers hope that people who are paralyzed will one day be able to

independently operate artificial limbs, computers or wheelchairs.

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.

BrainGate Systems Report

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