Testing a Prosthetic Haptic Feedback Simulator With an Interactive Force Matching Task

Prosthetic technology is a prime candidate for the integration of sensory feedback. Functional user testing of various haptic feedback modes is a necessary step to encourage commercial adoption. A haptic feedback simulator, using both a visual and vibrotactile representation of force, is coupled with an interactive force-matching task. This task provides an objective means to assess control of grasp force at three different target force levels. Results from eight subjects using a myoelectric prosthetic device show that visual feedback of force improved user performance at all force levels by reducing average force-matching error by 65%. Vibrotactile feedback led to improved performance in an experienced subgroup of subjects, showing 25% error reduction at the medium target force level. Furthermore, multiple practice sessions with the simulator are shown to reduce error rates. These findings suggest that prosthesis users may be able to improve their control of grasping force with a haptic feedback system. A haptic feedback simulator, such as the platform described here, will allow prosthesis users to practice with and customize the feedback to improve functionality and comfort.