Developing a Brain Computer Interface

Developing a consciousness computing machine portholeASeminar Report On mind Computer InterfaceSubmitted byName Sachin Kumar Roll No 1214310301ABSTRACTBrain Computer Interface allows drug mathematical functionrs to communicate with each others by using only champion activities with come go forth of the closet using any peripheral nerves and muscles of human body. On BCI enquiry the Electroencephalogram (pneumoencephalogram) is used for go intoing the galvanisingal body process along the scalp. electroencephalogram is used to measure the voltage fluctuations resulting from ionic current flows inside the neurons of the head. Hans Berger a German neuroscientist, in 1924 observed the electrical activity of human brain by using EEG. Hans Berger was the first one who recorded an alpha Wave from a human brain.In 1970, Defense Advanced query Projects Agency of USA initiated the architectural plan to explore brain colloquy using EEG. The papers published after this look as w ell position the first appearance of the expression braincomputer substance abuser interface in scientific literature. The field of BCI research and development has since focused primarily on neuroprosthetics applications that aim at restoring damaged hearing, sight and movement.Nowadays BCI research is going on in a full swing using non-invasive neural imaginary proficiency mostly the EEG. The future research on BCI leave be dependent mostly in nanotechnology. interrogation on BCI is radically increased over the last decade. From the last decade the maximum reading imparting pastures of BCI was 5-25 bits/min but at present BCIs maximum data transfer rate is 84.7bits/min.2.INTRODUCTIONBrain-computer interface (BCI) is alliance between a brain and a winding that enables argues from the brain to compute near external activities, such(prenominal) as control of a cursoror a prosthetic limb.The Brain computing interface enables a direct conversations pathway between the brain and the object to be controlled. For example, the channelise is contagious directly from the brain to the mechanism directing the cursor moves, rather than taking the normal ways with the bodys neuromuscular system from the brain to the finger on a mouse then directing the curser.BCIs Research began in the 1970s at the University of California Los Angeles(UCLA) under an allowance from the National Science Foundation, followed by a contract fromDARPA.Thanks to the remarkable cortical plasticity of the brain, signals from seted prostheses whoremaster, after adaptation, be handled by the brain like natural sensor or effector channels. Animal experimentation for years, the first neuroprosthetic devices implanted in humans appe bed in the mid-1990s.Current brain computing interface devices require calculated conscious conceit some future applications, such as prosthetic control, be likely to work without difficulty. Development of electrode devices and/or surgical methods that a re minimally invasive is one of the biggest challenges in developing BCI technology .Though Brain Computer Interface (BCI) facilitates direct communication between brain and computer or other device so nowadays it is astray used to enhance the possibility of communication for people with severe neuromuscular disorders, spinal cord injury. Except the medical applications BCI is also used for multimedia applications, which becomes possible by decode information directly from the users brain, as reflected in electroencephalographic (EEG)signals which are recorded non-invasively from users scalp.3.LITERATURE REVIEWCurrent Trends in Graz BrainComputer Interface (BCI)ResearchPfurtscheller, C. Neuper, C. Guger, W. Harkam, H. Ramoser,Schlgl, B. Obermaier, and M. PregenzerThe Graz BrainComputer Interface (BCI) project is aimed at developing a technical system that can support communication possibilities for patients with severe neuromuscular disabilities, who are in particular need of gai ning reliable control via non-muscular devices.This BCI system uses oscillating electroencephalogram (EEG) signals, recorded during specific mental activity, as input and provides a control option by its output. The withstand goted output signals are presently evaluated for different purposes, such as cursor control, selection of letters or words, or control of prosthesis.Between 1991 and 2000, the Graz BCI project moved through various stages of prototypes. In the first years, chiefly EEG patterns during willful limb movement were used for classification of single EEG trials. In these experiments, a cursor was moved e.g. to the left, right or downwards, depending on planning of left hand, right hand or foot movement. Extensive off-line analyses make believe shown that classification accuracy improved, when the input holds, such as electrode positions and oftenness mountains, were optimized in each subject. Apart from studies in healthy volunteers, BCI experiments were also p erformed in patients, e.g., with an amputated upper limb.The main separate of any BCI system areSignal acquisition system involves the electrodes, which pick up the electrical activity of the brain and the amplifier and analog filters.The feature extractor converts the brain signals into relevant feature components. At first, the EEG fond signals are filtered by a digital band pass filter. Then, the amplitude samples are squared to obtain the power samples. The power samples are averaged for all trials. Finally, the signal is smoothed by averaging over time samples.The feature translator classifies the feature components into logical controls.The control interface converts the logical controls into semantic controls.The device controller changes the semantic controls to physical device commands, which differ from one device to another depending on the application.Finally, the device commands are kill by the device.The early work of BCI was done byinvasivemethods with electrodes in serted into the brain tissue to read the signals of a single neuron. Although the spatio-temporal resolution was high and the results were highly accurate, there were complications in the long term. These were mostly attributable to the start tissue formation, which leads to a gradual weakening of the signal and even complete signal loss within months because of the brain tissue reaction towards the foreign objects.A proof of concept experiment was done by Nicolelis and Chapin on monkeys to control a robotic arm in real time using the invasive method. new-fashionedly, less(prenominal) invasive methods have been used by applying an array of electrodes in the subdural space over the cerebral cortex to record the Electrocorticogram (ECoG) signals. It has been found that ordinary Electroencephalogram pickup signals are averaged over several EEG signal bands (Hz) square inches, whereas ECoG electrodes can measure the electrical activity of brain cells over a often little area, thereb y providing much high spatial resolution and a higher signal to noise proportion because of the thinner barrier tissue between the electrodes and the brain cells. The superior susceptibility to record the gamma band signals of the brain tissue is another important advantage of this type of BCI system. Gamma rhythms (30-200 Hz) are produced by cells with higher oscillations, which are not easy to record by ordinary EEGs. The human skull is a thick filter, which blurs the EEG signals, especially the higher frequency bands (i.e. gamma band).Noninvasivetechniques were demonstrated mostly by electroencephalographs (EEG). Others used working(a) Hz, Magneto-Resonance Imaging (fMRI), Positron Electron Tomography (PET), Magneto encephalography (MEG) and Single Photon Emission Computed Tomography There (SPECT). EEGs have the advantage of higher temporal resolution, reaching a few milliseconds and are relatively low cost.Recent EEG systems have better spatiotemporal resolution of up to 256 electrodes over the total area of the scalp. Nevertheless, it cannot record from the deep parts of the brain. This is the main reason why the multi one million million million dollar fMRI systems are still the preferable method for the functional study of the brain. However, EEG systems are still the best candidate for BCI systems spatial as they are easy to use, portable and cheap.The main problems that reduce the reliability and accuracy of BCI and which prevent this technology from existence clinically useful, are the sensory interfacing problems and the translation algorithm problems. In order to make a clinically useful BCI the accuracy of the detection of intention needs to be very high and certainly much higher than the currently achieved accuracy with different types of BCI.The intermediate compromise between accuracy and safety is the ECoG establish BCI, which has shown considerable promise. The sensory arrays of electrodes areless invasive and provide comparable accuracy and high spatial resolution compared to the implanted type. The ECoG based BCI needs much less training than the EEG based BCI and researchers have shown that highly accurate and fast response.4.TECHNICAL DETAILSREASON BEHIND WORKINGThe reason a BCI workings at all is because of the way our brains function. Our brains are filled withneurons, individual nerve cells affiliated to one another by dendrites and axons. Every time we think, move, feel or remember something, our neurons are at work. That work is carried out by small electric signals that zip from neuron to neuron as fast as 250 mph. The signals are generated by differences in electric potential carried by ions on the membrane of each neuron.Although the paths the signals take are insulated by something called myelin, some of the electric signal escapes. Scientists can detect those signals, interpret what they mean and use them to direct a device of some kind. It can also work the other way around.For example, researchers could figure out what signals are sent to the brain by the optic nerve when someone imagines the color red. They could rig a camera that would send those exact signals into someones brain whenever the camera saw red, allowing a blind psyche to see without eyes.BCI INPUT AND OUTPUTOne of the biggest challenges facing brain-computer interface researchers today is the basic mechanics of the interface itself.The easiest and to the lowest degree invasive method is a set of electrodes a device known as anelectroencephalograph(EEG) attached to the scalp. The electrodes can read brain signals. However, the skull blocks a lot of the electrical signal, and it distorts what does get through.To get a higher-resolution signal, scientists can implant electrodes directly into the gray matter of the brain itself, or on the surface of the brain, beneath the skull. This allows for much more direct reception of electric signals and allows electrode placement in the specific area of the brain wh ere the appropriate signals are generated. This approach has many problems, however. It requires invasive surgery to implant the electrodes, and devices left in the brain long-term pitch to cause the formation of scar tissue in the gray matter. This scar tissue ultimately blocks signals. disregardless of the location of the electrodes, the basic mechanism is the same The electrodes measure minute differences in the voltage between neurons. The signal is then amplified and filtered. In current BCI systems, it is then interpreted by a computer program, although you might be familiar with older analogue encephalographs, which displayed the signals via pens that automatically wrote out the patterns on a continuous sheet of paper.In the case of a sensory input BCI, the function happens in reverse. A computer converts a signal, such as one from a video camera, into the voltages necessary to trigger neurons. The signals are sent to an implant in the proper area of the brain, and if everyt hing works correctly, the neurons fire and the subject receive a visual image alike to what the camera sees.SENSORY INPUTThe most common and oldest way to use a BCI is a cochlear implant. For the average person, sound waves enter the ear and pass through several tiny organs that in the end pass the vibrations on to the auditory nerves in the form of electric signals. If the mechanism of the ear is intemperately damaged, that person will be unable to hear anything. However, the auditory nerves may be work perfectly well. They just arent receiving any signals.A cochlear implant bypasses the non functioning part of the ear, processes the sound waves into electric signals and passes them via electrodes right to the auditory nerves. The result A previously deaf person can now hear. He might not hear perfectly, but it allows him to understand conversations.The processing of visual information by the brain is much more complex than that of audio information, so artificial eye developme nt isnt as advanced. Still, the rule is the same. Electrodes are implanted in or near the visual cortex, the area of the brain that processes visual information from the retinas. A pair of glasses holding small cameras is connected to a computer and, in turn, to the implants. after(prenominal) a training period similar to the one used for remote thinking-controlled movement, the subject can see. Again, the plenty isnt perfect, but refinements in technology have improved it tremendously since it was first attempted in the 1970s. Jens Naumann was the recipient of a second-generation implant. He was completely blind, but now he can navigate New York Citys subways by himself and even drive a car around a parking lot. In terms of lore fiction becoming reality, this process gets very close. The terminals that connect the camera glasses to the electrodes in Naumanns brain are similar to those used to connect the VISOR (Visual Instrument and Sensory Organ) worn by blind utilise scie nce officer Geordi La Forge in the Star Trek The Next Generation TVshow and films, and theyre both fundamentally the same technology. However, Naumann isnt able to see invisible portions of the electro magnetised spectrum.ApplicationsApplications of BCI are described as followsNeurogamingCurrently, there is a new field of gaming called Neurogaming, which uses non-invasive BCI in order to improve gameplay so that users can interact with a console without the use of a traditional controller. Some Neurogaming software use a players brain waves, kernel rate, expressions, pupil dilation, and even emotions to complete tasks or effect the mood of the game. For example, game developers at Emotiv have created non-invasive BCI that will determine the mood of a player and adjust music or scenery accordingly.This gaming palpate will introduce a real-time experience in gaming and will introduce the ability to control a video game by thought.Prosthesis controlNon-invasive BCIs have also been ap plied to enable brain-control of prosthetic upper and lower extremity devices in people with paralysis. For example, Gert Pfurtscheller of Graz University of Technology and colleagues demonstrated a BCI-controlled functional electrical stimulation system to restore upper extremity movements in a person with tetraplegia due to spinal cord injury. Between 2012 and 2013, researchers at the University of California, Irvine demonstrated for the first time that it is possible to use BCI technology to restore brain-controlled walking after spinal cord injury.Synthetic telepathy/silent communicationIn a $6.3 million Army initiative to invent devices for telepathic communication, Gerwin Schalk, underwritten in a $2.2 million grant, found that it is possible to use ECoG signals to discriminate the vowels and consonants embedded in spoken and in imagined words. The results shed luminousness on the distinct mechanisms associated with production of vowels and consonants, and could provide the b asis for brain-based communication using imagined speech. On February 27, 2013Duke University researchers successfully connected the brains of two rats with electronic interfaces that allowed them to directly share information, in the first-ever direct brain-to-brain interface.MEG and MRIMagnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) have both been used successfully as non-invasive BCIs. In a widely reported experiment, fMRI allowed two users being scanned to play Pongin real-time by altering their haemodynamic response or brain blood flow through biofeedback techniques.fMRI measurements of haemodynamic responses in real time have also been used to control robot arms with a seven second delay between thought and movement. nervous InternetAccess to the internet opens a myriad of opportunities for those with severe disabilities, including shopping, entertainment, education, and possibly even employment. Neural control users cannot control a cursor with a great degree of precision, so, therefore, the challenge of adapting a mesh browser for neural control is in making linkswhich are spatially organizedaccessible. The University of Tuebingen real a web browser controller to be used with their thought translation device, but it requires the user to select from an alphabetized list of links, causing problems if the link names are identical. They have developed a neurally controlled web browser that serializes the spatial internet interface and allows logical control of a web application.BrainTrainer mental object TrainingThe BrainTrainer project researches the most effective ways of teaching a person the brain-signal control unavoidable to interact with a device. The BrainTrainer toolset allows researchers to compose trials by providing simple tasks, such as targeting, navigation, selection, and timing, that can be feature to produce an appropriate-level task for a particular subject.