Seyed Yahya Moradi, Sajjad Jazini, Mohammad Oukati

Introduce

&

Processing

Brain-Computer-Interface (BCI) ?

“A system for controlling a device e.g. computer, wheelchair or a neuroprothesis by human intention which does not depend on the brain’s normal output pathways of peripheral nerves and muscles” [Wolpaw et al., 2002].

HCI – Human Computer Interface

DBI – Direct Brain Interface (University of Michigan)

TTD – Thought Translation Device (University of Tübingen)

1929 : HANS BERGER : EEG 1979 : DARPA : BCI

© http://en.wikipedia.org/wiki/Hans_Berger#mediaviewer/File:HansBerger_Univ_Jena.jpeg © http://upload.wikimedia.org/wikipedia/commons/thumb/6/6e/DARPA_Logo.jpg/1280px-DARPA_Logo.jpg

Some examples of BCI applications

BCI

BCI_

© Leeb et al., Computational Intelligence and Neuroscience, 2007 (doi:10.1155/2007/79642)

Brain Computer Interfaces

● Allow patients to control a computer by concious changes of brain activity

● Provide a means of communication to completeley paralysed patients:amyotrophic lateral sclerosis (ALS), cerebral palsy, locked in syndrome

● Have a very low data rate, typical a few bit per second or less

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Brain Computer Interfaces

Principles of operation:

© http://www.cortechsolutions.com/Applications/BCI2000_1.aspx

Brain Computer Interfaces – Electrophysilogical Activities used

● SCP Slow Cortical Potentials

● Mu Movement Imagination

● cortical neurons, direct brain interfaces

● P300, SSVEP ERP-Analysis

© http://en.wikipedia.org/wiki/Hans_Berger#mediaviewer/File:HansBerger_Univ_Jena.jpeg

Brain Computer Interfaces – SSVEP

● Steady State Visual Evoked Potentials derived from the visual (occipital) cortex

● focussing attention to visual stimuli of different frequency shows up in the EEG freqeuncy bands

● relibable and high transfer rate, but some prerequisites (eyes)

© http://www.cortechsolutions.com/Applications/BCI2000_1.aspx

Brain Computer Interfaces - P300 BCIs

● P300 wave – posivite component in the event related potential, 300msafter a stimulus

● natural response to events consideredas important

● selection of a symbol: count the flashes, algorithm averages trails and finds a P300

P300 runtime user interface

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