title: Stability and Workload of the Virtual Reality-Based Simulator-2.
abstract: To assess the stability of clinicians' and users' rating of electric-powered wheelchair (EPW) driving while using 4 different human-machine interfaces (HMIs) within the Virtual Reality-based SIMulator-version 2 (VRSIM-2) and in the real world (accounting for a total of 5 unique driving conditions).
  
  
  
  Within-subjects repeated-measures design.
  
  
  
  Simulation-based assessment in a research laboratory.
  
  
  
  A convenience sample of EPW athletes (N=21) recruited at the 31st National Veterans Wheelchair Games.
  
  
  
  Not applicable.
  
  
  
  Composite PMRT scores from the Power Mobility Road Test (PMRT); Raw Task Load Index; and the 6 subscale scores from the Task Load Index developed by the National Aeronautics and Space Administration (NASA-TLX).
  
  
  
  There was moderate stability (intraclass correlation coefficient between .50 and .75) in the total composite PMRT scores (P<.001) and the users' self-reported performance scores (P<.001) among the 5 driving conditions. There was a significant difference in the workload among the 5 different driving conditions as reflected by the Raw Task Load Index (P=.009). Subanalyses revealed this difference was due to the difference in the mental demand (P=.007) and frustration (P=.007) subscales. Post hoc analyses revealed that these differences in the NASA-TLX subscale scores were due to the differences between real-world and virtual driving scores, particularly attributable to the conditions (1 and 3) that lacked the rollers as a part of the simulation.
  
  
  
  Further design improvements in the simulator to increase immersion experienced by the EPW user, along with a standardized training program for clinicians to deliver PMRT in VRSIM-2, could improve the stability between the different HMIs and real-world driving.
authors.affiliation: Center of Excellence in Wheelchairs and Related Technology, Veterans Affairs Pittsburgh Healthcare System and Human Engineering Research Laboratories, Pittsburgh, PA; Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Deepan C
authors.initials: DC
authors.lastname: Kamaraj
authors.affiliation: Center of Excellence in Wheelchairs and Related Technology, Veterans Affairs Pittsburgh Healthcare System and Human Engineering Research Laboratories, Pittsburgh, PA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA. Electronic address: dicianno@pitt.edu.
authors.forename: Brad E
authors.initials: BE
authors.lastname: Dicianno
authors.affiliation: Center of Excellence in Wheelchairs and Related Technology, Veterans Affairs Pittsburgh Healthcare System and Human Engineering Research Laboratories, Pittsburgh, PA.
authors.forename: Harshal P
authors.initials: HP
authors.lastname: Mahajan
authors.affiliation: Center of Excellence in Wheelchairs and Related Technology, Veterans Affairs Pittsburgh Healthcare System and Human Engineering Research Laboratories, Pittsburgh, PA.
authors.forename: Alhaji M
authors.initials: AM
authors.lastname: Buhari
authors.affiliation: Center of Excellence in Wheelchairs and Related Technology, Veterans Affairs Pittsburgh Healthcare System and Human Engineering Research Laboratories, Pittsburgh, PA; Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Rory A
authors.initials: RA
authors.lastname: Cooper
mesh_terms: D003198:Computer Simulation; D006801:Humans; D015588:Observer Variation; D026741:Physical Therapy Modalities / Q000592:standards*; D015203:Reproducibility of Results; D014481:United States; D014493:United States Department of Veterans Affairs; D014584:User-Computer Interface; D014910:Wheelchairs; D016526:Workload / Q000523:psychology*
keywords: Durable medical equipment; Process assessment (health care); Rehabilitation; Reproducibility of results; Simulation training; Virtual reality exposure therapy; Wheelchairs