title: Advanced Joystick Algorithms for Computer Access Tasks.
abstract: OBJECTIVE
  To compare 2 correction algorithms and 2 joysticks (a conventional movement-sensing joystick and a custom-designed isometric joystick) in computer access tasks.
  
  
  METHODS
  Repeated-measures, within-subject.
  
  
  METHODS
  National Veterans Wheelchair Games.
  
  
  METHODS
  Fifteen participants with various diagnoses including multiple sclerosis, spinal cord injury, traumatic brain injury, Wilson disease, and Parkinson disease.
  
  
  METHODS
  A computer access test scenario was used to evaluate the effects of applying proportional integral derivative (PID)-based and least means-based algorithms to suppress unintentional cursor motions by users with upper extremity spasticity.
  
  
  METHODS
  Trial completion time, reaction time, and trajectory-based measures: movement offset, movement variability, and percentage of out-of-path motion on test tracks.
  
  
  RESULTS
  The quantitative outcome measures showed a high correlation with clinical measures for spasticity and functional independence. On small test tracks, compared to when no correction algorithms were used, both algorithms performed equally well in suppressing unintentional cursor motions. On longer test tracks, participants navigated most accurately while using the PID algorithm. Participants moved the cursor more accurately using the isometric joystick compared to the movement-sensing joystick, with only a slight increase in the task completion times.
  
  
  CONCLUSIONS
  The joysticks and the advanced correction algorithms show promise for use in wide-ranging applications as control interfaces.
authors.affiliation: Human Engineering Research Laboratories and Center of Excellence in Wheelchairs and Related Technology, VA Pittsburgh HealthCare System, 6425 Penn Avenue, Suite 400, Bakery Square, Pittsburgh, PA 15206; and Department of Rehabilitation Science and Technology and 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: Human Engineering Research Laboratories and Center of Excellence in Wheelchairs and Related Technology, VA Pittsburgh HealthCare System, Pittsburgh, PA; Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA(†).
authors.forename: Harshal
authors.initials: H
authors.lastname: Mahajan
authors.affiliation: Human Engineering Research Laboratories and Center of Excellence in Wheelchairs and Related Technology, VA Pittsburgh HealthCare System, Pittsburgh, PA; Department of Rehabilitation Science and Technology, Department of Physical Medicine and Rehabilitation, and Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA(‡).
authors.forename: Rory A
authors.initials: RA
authors.lastname: Cooper
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000503:physiopathology / Q000523:psychology*; D011597:Psychomotor Performance / Q000502:physiology*; D013647:Task Performance and Analysis; D014584:User-Computer Interface; D055815:Young Adult