Vibrotactile Feedback of Pose Error Enhances Myoelectric Control of a Prosthetic Hand

Advanced prosthetic hands offer the promise of great dexterity; however, myoelectric control techniques, successful with low degree-of-freedom prosthetics, are often set aside by amputees due to the lack of important sensations of touch and effort experienced in the interaction between prosthetic hand and task. In this paper, we explore the efficacy of various modalities of feedback (visual, tactile, visual and tactile, and none) conveying proprioceptive information, specifically the error in joint angles between a desired and actual pose of a virtual prosthetic hand. Our analysis of performance in achieving and maintaining a desired prosthetic hand pose indicates a significant effect of feedback condition, with visual and visual+tactile outperforming tactile alone and a no-feedback condition. Further, the combination of tactile and visual feedback does not seem to have significant drawbacks over visual feedback alone. For tasks that rely on proprioception in the absence of visual feedback, or when attention must be focused elsewhere, we see a performance benefit to the inclusion of tactile cueing, with no lags in reaction times or requirements for increased effort measured by muscle activation.