11-02-2010, 08:17 PM
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ABSTRACT
Brain Gate was developed by the bio-tech company Cyberkinetics in 2003 in Conjunction with the department of Neuroscience Brown University.
The device was designed to help those who have lost control of their limbs or other body function. The computer chip which is implanted into the brain, monitors brain activity in the patient and convert the intension of the user into computer hands. Currently the chip used 100 hair-thin electrodes that hear neurons firing in specific area of the brain. For e.g.: the area that control the arm movement .the activity is translated into eclectically charged signals and are then set and decoded using a program thus moving the arm. According to the Cyberkinetics website, 2 patients have been implanted with the Brain Gate.
The Brain Gate„¢ System is based on Cyber kinetics" platform technology to sense, transmit, analyze and apply the language of neurons. The System consists of a sensor that is implanted on the motor cortex of the brain and a device that analyzes brain signals. 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.
2. DESCRIPTION
2.1 A MEDICAL PRODUCT
The Brain Gate„¢ Neural Interface System is currently the subject of a pilot clinical trial being conducted under an Investigational Device Exemption (LDE) 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 to include the control of objects in the environment such as a telephone, a television and lights.
The Brain Gate„¢ System is based on Cyber kinetics' platform technology to sense, transmit, analyze and apply the language of neurons. The System consists of a sensor that is implanted on the motor cortex of the brain and a device that anah^es brain signals. 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.
Cyber kinetics is further developing the Brain Gate„¢ System to potentially provide limb movement to people with severe motor disabilities. The goal of this development program would be to allow these individuals to one day use their own arms and hands again. Limb movement developments are currently at the research stage and are not available for use with the existing Brain Gate„¢ System. In addition Cyber kinetics is developing products to allow for robotic control, such as a thought-controlled wheelchair.
2.2PLATFORM 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 developing products to restore function, as well as to monitor, detect, and respond to a variety of neurological diseases and disorders.
¢ Sense
Cyber kinetics' 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.
¢ Transmit and Analyze
The human brain is a super computer with the ability to instantaneously process vast amounts of information. Cyber kinetics' 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.
¢ 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 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.
¢ Brain Gate
Brain Gate was 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. 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 '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, thus moving the arm. According to the Cyber kinetics' website, two patients have been implanted with the Brain Gate system.
2.3 BRAINGATE INTERFACE
December 7,2004 an implantable, brain-computer interface the size of an aspirin has been clinically tested on humans by American company Cyber kinetics. The 'Brain Gate' device can provide paralysed 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.
Researchers at the University of Pittsburgh have already demonstrated that a monkey can feed itself with a robotic arm simply by using signals from its brain, an advance that could enhance prosthetics for people, especially those with spina] cord injuries. Now, using the Brain Gate system in the current human trials, a 25 year old quadriplegic has successfully been able to switch on lights, adjust the volume on a TV. change channels and read e-mail using only his brain. Crucially, the patient was able to do these tasks while carrying on a conversation and moving his head at the same time
About the Brain Gate device:-
The Brain Gate Neural Interface Device is a proprietary brain-computer interface that consists of an internal neural signal sensor and external processors that convert neural signals into an output signal under the users own control. The sensor consists of a tiny chip smaller than a baby aspirin, with one hundred electrode sensors each thinner than a hair that detect brain cell electrical activity.
2.4 BRAIN GATE
computer.
Again, the stuff of science fiction becomes a reality. A company called Cyber kinetics has created a technology that allows for the creation of direct, j'jjil!, jl^s reliable and bi-directional interfaces between the brain, nervous system and a
Their technology platform is called Brain Gate. It is the hope of this technology to translate thought into direct computer control. Cyber kinetics
describes that "such applications may include novel communications interfaces for motor impaired patients, as well as the monitoring and treatment of certain diseases which manifest themselves in patterns of brain activity, such as epilepsy and depression."
The Brain Gate neural interface device is based on ten years of development at Brown University; it is intended to provide severely disabled patients with a permanent, direct and reliable interface to a personal computer. Pending continued preclinical research success and regulatory approval by the Food and Drug Administration, the Company intends to initiate a pilot clinical trial this year.
2.5 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 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 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 stimuli
Gate 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 brain-machine 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.
Neuroprosthetics:-
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, 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.
2.6 BRAIN TAP
Scientists Gingerly Tap Into Brain's Power
by Kevin Maney - USA TODAY October 11, 2004
Today's science fiction could be tomorrow's reality - . .¢. 'JffiAudU^. and a
whole new world for everyone from paraplegics to fighter pilots
in a
Fox borough, Mass. - A 25-year-old quadriplegic sits
wheelchair with wires coming out of a bott'e-cap-size ft
connector stuck in his skull. *<¦
The wires run from 100 tiny sensors imp'anted in his ' ca^:'"2-X-:-.'-M'kW^S brain
and out to a computer. Using just his thoughts, this former high school football player is p!a>ing the computer game Pong.
It is part of a breakthrough trial, the first o^its kind, with far-reaching implications. Friday, early results were revealed at the American Academy of Physical Medicine and Rehabilitation annual conference. Cyberkinetics Neurotechnology Systems, the Foxborough-based company behind the technology, told attendees the man can use his thoughts to control a computer well enough to operate a TV, open e-mail and play Pong with "'0oo accuracy.
"The patient tells me this device has changed his life." says Jon Mukand, a physician caring for him at a rehabilitation facility in Warwick. R.I. The patient, who had the sensors implanted in June, has not been publicly identified. The significance of the technology, which Cyberkinetics call Braingate, goes far beyond the initial effort to help quadriplegics. It is an early step toward learning to read signals from an array of neurons and use computers and algorithms to translate the signals into action. That could lead to artificial limbs that work like the real thing: The user could think of moving a finger, and the finger would move.
j Neural activity V.Y.V VP converted to
r] output signal
The computer translates the signals into communication output, allowing a patiennomovea cursor on a computer screen merely by thinking about it.
Connecting brains to computers:-A way to help quadriplegics Cyber kinetics, a company commercializing technology developed
I
1 at Brown University, just reported the results of its first attempt to implant sensors into the brain of a quadriplegic. Signals from the sensor allow him to control a computer.
The brain in control:-
DMI is a field about to explode. At Duke University a research team has employed different methods to read and interpret neural signals directly from the human brain. Other research is underway at universities around the world. Atlanta-based Neural Signals - a pioneer in BMI for the handicapped - has also been developing a system for tapping directly into the brain
Patient gaining accuracy:-
Cyberkinetics technicians work with the former football player three times a week, trying to fine-tune the system so he can do more tasks. He can move a cursor around a screen. If he leaves the cursor on a spot and dwells on it, that works like a mouse click.
Once he can control a computer, the possibilities get interesting. A computer could drive a motorized wheelchair, allowing him to go where he thinks about going. It could control his environment - lights, heat, locking or unlocking doors. And he could tap out e-mails, albeit slowly,
3. CONCLUSION
The Brain Gate„¢ System is based on Cyber kinetics' platform technology to sense, transmit, analyze and apply the language of neurons. The System consists of a sensor that is implanted on the motor cortex of the brain and a device that analyzes brain signals. 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 brain in prior theories of neurochemistry had simply not been taken into account - pain was thought to be simply a direct response to a stimulus - the so-called pain/pleasure theory, a one-way "alarm system" like that proposed by Rene Descartes. This did not, for instance, explain why a carpenter can hit his thumb and not feel much pain, whereas a novice is doubled over in agony, nor did it explain phantom limb pain, when the signal is in fact impossible to receive, since the wiring for it is gone.
A major advantage of the theory is that those being taught pain control techniques can actually be told why they work. This seems to play a major role in achieving results - which is explained most readily by psychoneuroimmunology, in which the nerves are seen as the page link between the immune system and sensory and cognitive experience.
4. FUTURE SCOPE
Brain Gate, a tiny sensor array implanted in the brain, has allowed a quadriplegic man to check e-mail and play computer games - even manipulate the controls on a television. It is the most sophisticated implant of its kind.
In the future, the Brain Gate„¢ System could be used by those individuals whose injuries are less severe. Next generation products may be able to provide an individual with the ability to control devices that allow breathing, bladder and bowel movements Once he can control a computer, the possibilities get interesting. A computer could drive a motorized wheelchair, allowing him to go where he thinks about going. It could control his environment - lights, heat, locking or unlocking doors. And he could tap out e-mails, albeit slowly.
Further out, some experts believe, the technology could be built into a helmet or other device that could read neural signals from outside the skull, non-invasively. The Defense Advanced Research Projects Agency (DARPA) is funding research in this field, broadly known as Brain Machine Interface, or BMI.
To be certain, the technology today is experimental and crude, perhaps at a stage similar to the first pacemaker in 1950, which was the size of a boom box and delivered jolts through wires implanted in the heart.
1. Seminartopics.net.
2. Google.com.
3. wikipedia.com
5. BIBLIOGRAPHY
CONTENTS
Page No:
1. INTRODUCTION 1
2. DESCRIPTION
2.1) A MEDICAL PRODUCT 2
2.2) PLATFORM TECHNOLOGY 3
2.3) BRAINGATE INTERFACE 5
2.4) BRAINGATE 6
2.5) BRAIN-COMPUTER INTERFACE 7
2.6) BRAIN-TAP 14
3. CONCLUSION 18
4. FUTURE SCOPE 19
5. BIBLIOGRAPHY 20
ABSTRACT
Brain Gate was developed by the bio-tech company Cyberkinetics in 2003 in Conjunction with the department of Neuroscience Brown University.
The device was designed to help those who have lost control of their limbs or other body function. The computer chip which is implanted into the brain, monitors brain activity in the patient and convert the intension of the user into computer hands. Currently the chip used 100 hair-thin electrodes that hear neurons firing in specific area of the brain. For e.g.: the area that control the arm movement .the activity is translated into eclectically charged signals and are then set and decoded using a program thus moving the arm. According to the Cyberkinetics website, 2 patients have been implanted with the Brain Gate.
The Brain Gate„¢ System is based on Cyber kinetics" platform technology to sense, transmit, analyze and apply the language of neurons. The System consists of a sensor that is implanted on the motor cortex of the brain and a device that analyzes brain signals. 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.
2. DESCRIPTION
2.1 A MEDICAL PRODUCT
The Brain Gate„¢ Neural Interface System is currently the subject of a pilot clinical trial being conducted under an Investigational Device Exemption (LDE) 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 to include the control of objects in the environment such as a telephone, a television and lights.
The Brain Gate„¢ System is based on Cyber kinetics' platform technology to sense, transmit, analyze and apply the language of neurons. The System consists of a sensor that is implanted on the motor cortex of the brain and a device that anah^es brain signals. 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.
Cyber kinetics is further developing the Brain Gate„¢ System to potentially provide limb movement to people with severe motor disabilities. The goal of this development program would be to allow these individuals to one day use their own arms and hands again. Limb movement developments are currently at the research stage and are not available for use with the existing Brain Gate„¢ System. In addition Cyber kinetics is developing products to allow for robotic control, such as a thought-controlled wheelchair.
2.2PLATFORM 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 developing products to restore function, as well as to monitor, detect, and respond to a variety of neurological diseases and disorders.
¢ Sense
Cyber kinetics' 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.
¢ Transmit and Analyze
The human brain is a super computer with the ability to instantaneously process vast amounts of information. Cyber kinetics' 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.
¢ 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 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.
¢ Brain Gate
Brain Gate was 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. 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 '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, thus moving the arm. According to the Cyber kinetics' website, two patients have been implanted with the Brain Gate system.
2.3 BRAINGATE INTERFACE
December 7,2004 an implantable, brain-computer interface the size of an aspirin has been clinically tested on humans by American company Cyber kinetics. The 'Brain Gate' device can provide paralysed 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.
Researchers at the University of Pittsburgh have already demonstrated that a monkey can feed itself with a robotic arm simply by using signals from its brain, an advance that could enhance prosthetics for people, especially those with spina] cord injuries. Now, using the Brain Gate system in the current human trials, a 25 year old quadriplegic has successfully been able to switch on lights, adjust the volume on a TV. change channels and read e-mail using only his brain. Crucially, the patient was able to do these tasks while carrying on a conversation and moving his head at the same time
About the Brain Gate device:-
The Brain Gate Neural Interface Device is a proprietary brain-computer interface that consists of an internal neural signal sensor and external processors that convert neural signals into an output signal under the users own control. The sensor consists of a tiny chip smaller than a baby aspirin, with one hundred electrode sensors each thinner than a hair that detect brain cell electrical activity.
2.4 BRAIN GATE
computer.
Again, the stuff of science fiction becomes a reality. A company called Cyber kinetics has created a technology that allows for the creation of direct, j'jjil!, jl^s reliable and bi-directional interfaces between the brain, nervous system and a
Their technology platform is called Brain Gate. It is the hope of this technology to translate thought into direct computer control. Cyber kinetics
describes that "such applications may include novel communications interfaces for motor impaired patients, as well as the monitoring and treatment of certain diseases which manifest themselves in patterns of brain activity, such as epilepsy and depression."
The Brain Gate neural interface device is based on ten years of development at Brown University; it is intended to provide severely disabled patients with a permanent, direct and reliable interface to a personal computer. Pending continued preclinical research success and regulatory approval by the Food and Drug Administration, the Company intends to initiate a pilot clinical trial this year.
2.5 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 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 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 stimuli
Gate 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 brain-machine 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.
Neuroprosthetics:-
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, 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.
2.6 BRAIN TAP
Scientists Gingerly Tap Into Brain's Power
by Kevin Maney - USA TODAY October 11, 2004
Today's science fiction could be tomorrow's reality - . .¢. 'JffiAudU^. and a
whole new world for everyone from paraplegics to fighter pilots
in a
Fox borough, Mass. - A 25-year-old quadriplegic sits
wheelchair with wires coming out of a bott'e-cap-size ft
connector stuck in his skull. *<¦
The wires run from 100 tiny sensors imp'anted in his ' ca^:'"2-X-:-.'-M'kW^S brain
and out to a computer. Using just his thoughts, this former high school football player is p!a>ing the computer game Pong.
It is part of a breakthrough trial, the first o^its kind, with far-reaching implications. Friday, early results were revealed at the American Academy of Physical Medicine and Rehabilitation annual conference. Cyberkinetics Neurotechnology Systems, the Foxborough-based company behind the technology, told attendees the man can use his thoughts to control a computer well enough to operate a TV, open e-mail and play Pong with "'0oo accuracy.
"The patient tells me this device has changed his life." says Jon Mukand, a physician caring for him at a rehabilitation facility in Warwick. R.I. The patient, who had the sensors implanted in June, has not been publicly identified. The significance of the technology, which Cyberkinetics call Braingate, goes far beyond the initial effort to help quadriplegics. It is an early step toward learning to read signals from an array of neurons and use computers and algorithms to translate the signals into action. That could lead to artificial limbs that work like the real thing: The user could think of moving a finger, and the finger would move.
j Neural activity V.Y.V VP converted to
r] output signal
The computer translates the signals into communication output, allowing a patiennomovea cursor on a computer screen merely by thinking about it.
Connecting brains to computers:-A way to help quadriplegics Cyber kinetics, a company commercializing technology developed
I
1 at Brown University, just reported the results of its first attempt to implant sensors into the brain of a quadriplegic. Signals from the sensor allow him to control a computer.
The brain in control:-
DMI is a field about to explode. At Duke University a research team has employed different methods to read and interpret neural signals directly from the human brain. Other research is underway at universities around the world. Atlanta-based Neural Signals - a pioneer in BMI for the handicapped - has also been developing a system for tapping directly into the brain
Patient gaining accuracy:-
Cyberkinetics technicians work with the former football player three times a week, trying to fine-tune the system so he can do more tasks. He can move a cursor around a screen. If he leaves the cursor on a spot and dwells on it, that works like a mouse click.
Once he can control a computer, the possibilities get interesting. A computer could drive a motorized wheelchair, allowing him to go where he thinks about going. It could control his environment - lights, heat, locking or unlocking doors. And he could tap out e-mails, albeit slowly,
3. CONCLUSION
The Brain Gate„¢ System is based on Cyber kinetics' platform technology to sense, transmit, analyze and apply the language of neurons. The System consists of a sensor that is implanted on the motor cortex of the brain and a device that analyzes brain signals. 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 brain in prior theories of neurochemistry had simply not been taken into account - pain was thought to be simply a direct response to a stimulus - the so-called pain/pleasure theory, a one-way "alarm system" like that proposed by Rene Descartes. This did not, for instance, explain why a carpenter can hit his thumb and not feel much pain, whereas a novice is doubled over in agony, nor did it explain phantom limb pain, when the signal is in fact impossible to receive, since the wiring for it is gone.
A major advantage of the theory is that those being taught pain control techniques can actually be told why they work. This seems to play a major role in achieving results - which is explained most readily by psychoneuroimmunology, in which the nerves are seen as the page link between the immune system and sensory and cognitive experience.
4. FUTURE SCOPE
Brain Gate, a tiny sensor array implanted in the brain, has allowed a quadriplegic man to check e-mail and play computer games - even manipulate the controls on a television. It is the most sophisticated implant of its kind.
In the future, the Brain Gate„¢ System could be used by those individuals whose injuries are less severe. Next generation products may be able to provide an individual with the ability to control devices that allow breathing, bladder and bowel movements Once he can control a computer, the possibilities get interesting. A computer could drive a motorized wheelchair, allowing him to go where he thinks about going. It could control his environment - lights, heat, locking or unlocking doors. And he could tap out e-mails, albeit slowly.
Further out, some experts believe, the technology could be built into a helmet or other device that could read neural signals from outside the skull, non-invasively. The Defense Advanced Research Projects Agency (DARPA) is funding research in this field, broadly known as Brain Machine Interface, or BMI.
To be certain, the technology today is experimental and crude, perhaps at a stage similar to the first pacemaker in 1950, which was the size of a boom box and delivered jolts through wires implanted in the heart.
1. Seminartopics.net.
2. Google.com.
3. wikipedia.com
5. BIBLIOGRAPHY
CONTENTS
Page No:
1. INTRODUCTION 1
2. DESCRIPTION
2.1) A MEDICAL PRODUCT 2
2.2) PLATFORM TECHNOLOGY 3
2.3) BRAINGATE INTERFACE 5
2.4) BRAINGATE 6
2.5) BRAIN-COMPUTER INTERFACE 7
2.6) BRAIN-TAP 14
3. CONCLUSION 18
4. FUTURE SCOPE 19
5. BIBLIOGRAPHY 20
