1 / 22

Department of ECE

Department of ECE. Brain Computer Interface. Submitted By: Saurabh Gupta RD6801B44. Brain-Computer Interfaces Past, Present and Future. What is a BCI?.

francois-lesage
Download Presentation

Department of ECE

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Department of ECE Brain Computer Interface Submitted By: Saurabh Gupta RD6801B44

  2. Brain-Computer InterfacesPast, Present and Future

  3. What is a BCI? • BCIs read electrical signals or other manifestations of brain activity and translate them into a digital form that computers can understand, process, and convert into actions of some kind, such as moving a cursor or turning on a TV. • BCI can help people with inabilities to control computers, wheelchairs, televisions, or other devices with brain activity.

  4. The 3 major components of BCIs • Ways of measuring neural signals from the human brain • Methods and algorithms for decoding brain states/intentions from these signals and • Methodology and algorithms for mapping the decoded brain activity to intended behavior or action.

  5. History – Discovering the Basics • 1924: Hans Berger discovers the EEG • Analyses the interrelation of EEG and brain diseases • 1970: First developments to use brain waves as input • ARPA has vision of enhanced human • First step in the right direction Historical overview

  6. History - Monkey first … • 1990: First successful experiments with monkeys • Implanting electrode arrays into monkey brains • Recording of monkeys‘ brain waves • Offline reproducing of movements • 2000: Monkeys control robots by thoughts Historical overview

  7. History - … Humans follow • More non-invasive than invasive approaches • Brain reading by eg. EEG, MEG or fMRI • 2004: First human benefits from research • Matt Nagle is able to control a computer and move a prosthetic hand Historical overview

  8. Reading the brain… Electroencephalogy (EEG) Direct Neural Contact • Most accurate method • Highly invasive • Not possible with current technologies • Perhaps possible in future with e.g. nanobots • Measures electical activity in brain • Non-invasive • Susceptible to noise • Easy to use + low cost + portable • Most commonly used device in BCIs Reading the brain

  9. Invasive versus Non-invasive BCI • Invasive techniques, which implant electrodes directly onto a patient’s brain; • Noninvasive techniques, in which medical scanning devices or sensors mounted on caps or headbands read brain signals.

  10. …Reading the brain Functional Magnetic Resonance Imaging (fMRI) Magnetoencephalogy (MEG) • Measures magnetic fields produced by electrical activity in brain • Non-invasive • Very accurate • High equiment requirements and maintenance costs • Measures blood flow in brain using MRI (haemodynamics) • Blood flow correlates to neural activity • Studies the brain‘s function • Very accurate • Very high costs due to MRI Reading the brain

  11. Direct Interfaces via EEG • Required if haptic or linguistic interfaces inoperable (“locked in”) • Four typical techniques: • VEP • P300 • ERS/ERD • SSVEP Direct Interface Techniques

  12. VEP - Background • “visual evoked potential” • caused by visual stimulation • occurs with flashing lights (3 – 6 Hz) Direct Interface Techniques

  13. VEP - Application • Checkerboard with 64 fields • letters • words • “Splitting keyboard” Direct Interface Techniques

  14. P300 - Background • positive curve on EEG after 300ms • relevant & seldom stimulation • strongest signal at parietal lobe Direct Interface Techniques

  15. P300 - Application • Typing tool with 6x6 fields • Letter identification by column, row • Consecutive iteration • ~ 30 sec / letter Direct Interface Techniques

  16. ERS/ERD - Application • Event related synchronization / desynchronization • Imagined hand/foot movement • Cursor movement • FES coupling (functional electrical stimulation) Direct Interface Techniques

  17. SSVEP - Background • steady state visual evoked potential • steady amplitude on EEG • based on flickering neon tubes • amplitude consciously modifiable • biofeedback Direct Interface Techniques

  18. SSVEP - Example • Flight simulator • amplitude < threshold: left • amplitude > threshold: right Direct Interface Techniques

  19. BCI Applications… • Medical applications: • Possibly only communication channel for people suffering from e.g. paraplegia, amyotrophia • Neuroprosthetics: • Surgically implanted devices used as replacement for damaged neurons • Currently available: cochlear implant (bionic ear) BCI Applications

  20. …BCI Applications • Human enhancement • Cyberntic Organisms • Brainwave Synchronization • Exocortex (intelligence booster) • Human manipulation • Mind-Control • „Neurohacking“: unwanted reading of information from the brain BCI Applications

  21. Current Projects • Berlin Brain-Computer-Interface • Joint Venture of several German research organisations • Supported by the Ministry of Education and Research • Graz Brain-Computer-Interface • Wide range of research topics • Impressive combination of BCI and FES (Functional Electrical Stimulation)

  22. Questions ?

More Related