title: Vibrotactile grasping force and hand aperture feedback for myoelectric forearm prosthesis users.
abstract: BACKGROUND
  User feedback about grasping force and hand aperture is very important in object handling with myoelectric forearm prostheses but is lacking in current prostheses. Vibrotactile feedback increases the performance of healthy subjects in virtual grasping tasks, but no extensive validation on potential users has been performed.
  
  
  OBJECTIVE
  Investigate the performance of upper-limb loss subjects in grasping tasks with vibrotactile stimulation, providing hand aperture, and grasping force feedback.
  
  
  METHODS
  Cross-over trial.
  
  
  METHODS
  A total of 10 subjects with upper-limb loss performed virtual grasping tasks while perceiving vibrotactile feedback. Hand aperture feedback was provided through an array of coin motors and grasping force feedback through a single miniature stimulator or an array of coin motors. Objects with varying sizes and weights had to be grasped by a virtual hand.
  
  
  RESULTS
  Percentages correctly applied hand apertures and correct grasping force levels were all higher for the vibrotactile feedback condition compared to the no-feedback condition. With visual feedback, the results were always better compared to the vibrotactile feedback condition. Task durations were comparable for all feedback conditions.
  
  
  CONCLUSIONS
  Vibrotactile grasping force and hand aperture feedback improves grasping performance of subjects with upper-limb loss. However, it should be investigated whether this is of additional value in daily-life tasks.
  
  
  CONCLUSIONS
  This study is a first step toward the implementation of sensory vibrotactile feedback for users of myoelectric forearm prostheses. Grasping force feedback is crucial for optimal object handling, and hand aperture feedback is essential for reduction of required visual attention. Grasping performance with feedback is evaluated for the potential users.
authors.affiliation: Biomedical Signals and Systems, MIRA institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, The Netherlands h.j.b.witteveen@utwente.nl.
authors.forename: Heidi J B
authors.initials: HJ
authors.lastname: Witteveen
authors.affiliation: Roessingh Research and Development, Enschede, The Netherlands Biomechanical Engineering, MIRA institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, the Netherlands.
authors.forename: Hans S
authors.initials: HS
authors.lastname: Rietman
authors.affiliation: Biomedical Signals and Systems, MIRA institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Veltink
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000674:Amputees / Q000534:rehabilitation; D001186:Artificial Limbs; D016022:Case-Control Studies; D018592:Cross-Over Studies; D011211:Electric Power Supplies; D056228:Feedback, Sensory / Q000502:physiology*; D005260:Female; D005542:Forearm; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011884:Radius / Q000601:surgery; D014110:Touch / Q000502:physiology*; D016896:Treatment Outcome
keywords: Upper-limb prosthetics; grasping force feedback; hand aperture feedback; vibrotactile stimulation; virtual grasping tasks