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Force control strategies while driving electric powered wheelchairs with isometric and movement-sensing joysticks

Dicianno, BE and Spaeth, DM and Cooper, RA and Fitzgerald, SG and Boninger, ML and Brown, KW (2007) Force control strategies while driving electric powered wheelchairs with isometric and movement-sensing joysticks. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 15 (1). 144 - 150. ISSN 1534-4320

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Innovations to control interfaces for electric powered wheelchairs (EPWs) could benefit 220 000 current users and over 125 000 individuals who desire mobility but cannot use a conventional motion sensing joystick (MSJ). We developed a digital isometric joystick (IJ) with sophisticated signal processing and two control functions. In a prior study, subjects' driving accuracy with our IJ was comparable to using an MSJ. However, we observed subjects using excessive force on the IJ possibly because its rigid post provides no positional feedback. Thus, this paper examines the time-series data recorded in the previous study to characterize subjects' force control strategies since weakness is a concern. Eleven EPW users with upper limb impairments drove an EPW using an IJ with two different control functions and an MSJ in a Fitts' law paradigm. Subjects relied upon positional feedback from the MSJ and used appropriate force. In contrast, subjects using the IJ with either control function applied significantly higher force than necessary (p< 0.0001 and p=0.0058). Using higher average force was correlated with quicker trial times but not associated with accuracy. Lack of positional feedback may result in use of excess isometric force. Modifying control functions, adjusting gain, or providing additional training or feedback might address this problem. © 2007 IEEE.


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Item Type: Article
Status: Published
CreatorsEmailPitt UsernameORCID
Dicianno, BEdicianno@pitt.eduDICIANNO0000-0003-0738-0192
Spaeth, DM
Fitzgerald, SG
Boninger, MLboninger@pitt.eduBONINGER
Brown, KW
Centers: Other Centers, Institutes, Offices, or Units > Human Engineering Research Laboratories
Date: 1 March 2007
Date Type: Publication
Journal or Publication Title: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Volume: 15
Number: 1
Page Range: 144 - 150
DOI or Unique Handle: 10.1109/tnsre.2007.891394
Schools and Programs: School of Health and Rehabilitation Sciences > Rehabilitation Science and Technology
Refereed: Yes
ISSN: 1534-4320
MeSH Headings: Adolescent; Adult; Aged; Aged, 80 and over; Arm--physiopathology; Computer Peripherals; Female; Humans; Isometric Contraction; Male; Man-Machine Systems; Middle Aged; Movement; Muscle, Skeletal--physiopathology; Psychomotor Performance; Stress, Mechanical; User-Computer Interface; Wheelchairs
PubMed ID: 17436887
Date Deposited: 12 Oct 2012 18:29
Last Modified: 05 Feb 2019 00:55


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