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    1. 1. BRAIN COMPUTER INTERFACE (BCI) Popular Science Feb. 2004
    2. 2. <ul><li>A brain-computer interface is a direct communication pathway between a human or animal brain ( or brain cell culture) and an external device. </li></ul><ul><li>Sometimes called a direct neural interface or a brain machine interface (BMI). </li></ul>Brain Computer Interface
    3. 3. <ul><li>In USA, more than 200,000 patients live with the motor sequelae (consequences) of serious injury. There are two ways to help them restore some motor function: </li></ul><ul><li>Repair the damaged nerve axons. </li></ul><ul><li>Build neuroprosthetic device. </li></ul>Nicolelis, 2001 Motivation for BCI/BMI Research
    4. 4. <ul><li>Invasive BCI </li></ul><ul><li>Non-Invasive BCI </li></ul>Detecting neural activity
    5. 5. <ul><li>Invasive BCI are directly implanted into the grey matter of the brain during neurosurgery. </li></ul><ul><li>They produce the highest quality signals of BCI devices . </li></ul><ul><li>Prone to building up of scar-tissue </li></ul><ul><li>Targeted repairing damaged sight and providing new functionality to paralyzed people (neuroprosthetics). </li></ul>Invasive BCI
    6. 6. Invasive BCI
    7. 7. <ul><li>Neuroimaging technologies as interfaces are used. </li></ul><ul><li>Signals recorded in this way have been used to power muscle implants and restore partial movement in an experimental volunteer. </li></ul><ul><li>Non-invasive implants produce poor signal resolution . </li></ul>Non Invasive BCI
    8. 8. Non Invasive BCI
    9. 9. EEG <ul><li>Electroencephalography (EEG) is the measurement of electrical activity produced by the brain as recorded from electrodes placed on the scalp. </li></ul>Mussa-Ivaldi & Miller, 2003
    10. 10. EEG Data Recordings of brainwaves produced by an electroencephalogram
    11. 11. Typing words by mind
    12. 12. Help impaired hands to grasp by mind EEG-MRP Hold cup for drinking
    13. 13. Play videogames by mind Leuthardt et al.,2004 ECoG based BCI Video Pfurtscheller et al., 2003
    14. 14. Neuron spike based BCI <ul><li>high speed real time control </li></ul><ul><li>precise control of movement </li></ul><ul><li>invasive </li></ul><ul><li>high risk for clinical application </li></ul>Nicolelis, 2001
    15. 15. Miguel Nicolelis Experiment Diagram of the BCI developed by Miguel Nicolelis and collegues for use on Rhesus monkeys
    16. 16. Real time movement of 2d/3d objects 2D movement control 3D movement control
    17. 17. Animal BCI Research Garrett Stanley's recordings of cat vision using a BCI implanted in the lateral geniculate nucleus (top row: original image; bottom row: recording)
    18. 18. Working of Simple BCI Schematic diagram of a BCI system
    19. 19. <ul><li>P300 detection </li></ul><ul><li>EEG mu-Rhythm Conditioning </li></ul><ul><li>VEP Detection </li></ul>BCI Methods
    20. 20. <ul><li>How can you type words by mind? </li></ul><ul><li>The P300 (P3) wave is an event related potential (ERP) which can be recorded via electroencephalography (EEG) as a positive deflection in voltage at a latency of roughly 300 ms in the EEG. </li></ul>P300 Detection
    21. 21. Experiment Design <ul><li>Alphabet row/column was flashing randomly on the computer screen </li></ul><ul><li>Human subject was gazing at the screen </li></ul><ul><li>Human EEG was recorded simultaneously </li></ul><ul><li>P300 components in EEG was extracted in real time for letter guess </li></ul>EEG amplifier Human subject Visual feedback
    22. 22. Experiment Design (Donchin, 1988, 2000) Flashing of rows/columns containing the desired letter will elicit P300 response at vertex
    23. 23. Application Release The Power of Brain
    24. 24. 1.Artificial Sensory channel Artificial Hearing Since 1978, about 70,000 cochlear recipients worldwide.
    25. 25. Artificial Vision
    26. 26. 2. Artificial Motor Channel Nicolelis, 2001 Nicolelis, 2001
    27. 27. 3. Neural Disorder Control Parkinson’s disease Seizure prediction and control Nicolelis, 2001
    28. 28. <ul><li>BrainGate is a brain implant system developed by the bio-tech company Cyberkinetics in 2003 in conjunction with the Department of Neuroscience at Brown University. </li></ul>FDA approval for brain implant Cyberkinetics Inc. Neural Signals Inc.
    29. 29. Future: Silicon Cognition Ted Berger , University of Southern California MIT Technology Review, May 2003
    30. 30. Silicon Cognition Ted Berger , University of Southern California MIT Technology Review, May 2003
    31. 31. <ul><li>BCIs will help creating a Direct communication pathway between a human or animal brain and any external devices like computers. </li></ul><ul><li>BCI has increased the possibility of treatment of disabilities related to nervous system along with the old technique of Neuroprosthetics. </li></ul><ul><li>Techniques like EEG, MEG and neurochips have come into discussions since the BCI application have started developing. </li></ul><ul><li>This has provided a new work area for scientists and researchers around the world. </li></ul>Advantages
    32. 32. Disadvantages <ul><li>In case of Invasive BCI there is a risk of formation of scar tissue. </li></ul><ul><li>There is a need of extensive training before user can use techniques like EEG </li></ul><ul><li>BCI techniques still require much enhancement before they can be used by users as they are slow. </li></ul><ul><li>Ethical implications of BCI will arise in future </li></ul><ul><li>BCI techniques are costly. It requires a lot of money to set up the BCI environment. </li></ul>
    33. 33. <ul><li>Brain-Computer Interface (BCI) is a method of communication based on voluntary neural activity generated by the brain and independent of its normal output pathways of peripheral nerves and muscles. </li></ul><ul><li>The neural activity used in BCI can be recorded using invasive or noninvasive techniques. </li></ul><ul><li>We can say as detection techniques and experimental designs improve, the BCI will improve as well and would provide wealth alternatives for individuals to interact with their environment. </li></ul>Conclusion
    34. 34. Refrences <ul><li> </li></ul><ul><li> </li></ul><ul><li> </li></ul>