Computational Intelligence and Neuroscience
Volume 2007 (2007), Article ID 79642, 8 pages
doi:10.1155/2007/79642
Research Article

Self-Paced (Asynchronous) BCI Control of a Wheelchair in Virtual Environments: A Case Study with a Tetraplegic

Robert Leeb,1 Doron Friedman,2,3 Gernot R. Müller-Putz,1 Reinhold Scherer,1 Mel Slater,2,4 and Gert Pfurtscheller1

1Laboratory of Brain-Computer Interfaces, Institute for Knowledge Discovery, Graz University of Technology, Krenngasse 37, Graz 8010, Austria
2Department of Computer Science, University College London, Gower Street, London WC1E 6BT, UK
3Sammy Ofer School of Communications, The Interdisciplinary Center, P.O. Box 167, Herzliya 08010, Israel
4Catalan Institute of Research and Advanced Studies (ICREA), Polytechnic University of Catalunya, Barcelona 08010, Spain

Received 18 February 2007; Accepted 17 July 2007

Academic Editor: Andrzej Cichocki

Copyright © 2007 Robert Leeb et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The aim of the present study was to demonstrate for the first time that brain waves can be used by a tetraplegic to control movements of his wheelchair in virtual reality (VR). In this case study, the spinal cord injured (SCI) subject was able to generate bursts of beta oscillations in the electroencephalogram (EEG) by imagination of movements of his paralyzed feet. These beta oscillations were used for a self-paced (asynchronous) brain-computer interface (BCI) control based on a single bipolar EEG recording. The subject was placed inside a virtual street populated with avatars. The task was to “go” from avatar to avatar towards the end of the street, but to stop at each avatar and talk to them. In average, the participant was able to successfully perform this asynchronous experiment with a performance of 90%, single runs up to 100%.