title: Toward brain-computer interface based wheelchair control utilizing tactually-evoked event-related potentials.
abstract: BACKGROUND
  People with severe disabilities, e.g., due to neurodegenerative disease, depend on technology that allows for accurate wheelchair control. For those who cannot operate a wheelchair with a joystick, brain-computer interfaces (BCI) may offer a valuable option. Technology depending on visual or auditory input may not be feasible as these modalities are dedicated to processing of environmental stimuli (e.g., recognition of obstacles, ambient noise). Herein we thus validated the feasibility of a BCI based on tactually-evoked event-related potentials (ERP) for wheelchair control. Furthermore, we investigated use of a dynamic stopping method to improve speed of the tactile BCI system.
  
  
  METHODS
  Positions of four tactile stimulators represented navigation directions (left thigh: move left; right thigh: move right; abdomen: move forward; lower neck: move backward) and N = 15 participants delivered navigation commands by focusing their attention on the desired tactile stimulus in an oddball-paradigm.
  
  
  RESULTS
  Participants navigated a virtual wheelchair through a building and eleven participants successfully completed the task of reaching 4 checkpoints in the building. The virtual wheelchair was equipped with simulated shared-control sensors (collision avoidance), yet these sensors were rarely needed.
  
  
  CONCLUSIONS
  We conclude that most participants achieved tactile ERP-BCI control sufficient to reliably operate a wheelchair and dynamic stopping was of high value for tactile ERP classification. Finally, this paper discusses feasibility of tactile ERPs for BCI based wheelchair control.
authors.affiliation: Department of Psychology I, University of Würzburg, Marcusstr 9-11, Würzburg 97070, Germany. tobias.kaufmann@uni-wuerzburg.de.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kaufmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Herweg
authors.forename: Andrea
authors.initials: A
authors.lastname: Kübler
mesh_terms: D000293:Adolescent; D000328:Adult; D062207:Brain-Computer Interfaces; D005071:Evoked Potentials / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D014110:Touch; D014910:Wheelchairs; D055815:Young Adult