title: Oculo-vestibular recoupling using galvanic vestibular stimulation to mitigate simulator sickness.
abstract: BACKGROUND
  Despite improvement in the computational capabilities of visual displays in flight simulators, intersensory visual-vestibular conflict remains the leading cause of simulator sickness (SS). By using galvanic vestibular stimulation (GVS), the vestibular system can be synchronized with a moving visual field in order to lessen the mismatch of sensory inputs thought to result in SS.
  
  
  METHODS
  A multisite electrode array was used to deliver combinations of GVS in 21 normal subjects. Optimal electrode combinations were identified and used to establish GVS dose-response predictions for the perception of roll, pitch, and yaw. Based on these data, an algorithm was then implemented in flight simulator hardware in order to synchronize visual and GVS-induced vestibular sensations (oculo-vestibular-recoupled or OVR simulation). Subjects were then randomly exposed to flight simulation either with or without OVR simulation. A self-report SS checklist was administered to all subjects after each session. An overall SS score was calculated for each category of symptoms for both groups.
  
  
  RESULTS
  The analysis of GVS stimulation data yielded six unique combinations of electrode positions inducing motion perceptions in the three rotational axes. This provided the algorithm used for OVR simulation. The overall SS scores for gastrointestinal, central, and peripheral categories were 17%, 22.4%, and 20% for the Control group and 6.3%, 20%, and 8% for the OVR group, respectively.
  
  
  CONCLUSIONS
  When virtual head signals produced by GVS are synchronized to the speed and direction of a moving visual field, manifestations of induced SS in a cockpit flight simulator are significantly reduced.
authors: Division of Otolaryngology-Head and Neck Surgery and Audiology, Aerospace Medicine and Vestibular Research Laboratory (AMVRL), Mayo Clinic, 13400 E. Shea Blvd, Scottsdale, AZ 85259, USA. mcevette@mayo.edu
authors: Michael J
authors: MJ
authors: Cevette
authors: Jan
authors: J
authors: Stepanek
authors: Daniela
authors: D
authors: Cocco
authors: Anna M
authors: AM
authors: Galea
authors: Gaurav N
authors: GN
authors: Pradhan
authors: Linsey S
authors: LS
authors: Wagner
authors: Sarah R
authors: SR
authors: Oakley
authors: Benn E
authors: BE
authors: Smith
authors: David A
authors: DA
authors: Zapala
authors: Kenneth H
authors: KH
authors: Brookler
mesh_terms: D000328:Adult; D000337:Aerospace Medicine; D004599:Electric Stimulation Therapy; D005260:Female; D006801:Humans; D008297:Male; D009041:Motion Sickness / Q000517:prevention & control*; D009949:Orientation; D012027:Reflex, Vestibulo-Ocular; D014584:User-Computer Interface; D014722:Vestibule, Labyrinth