Innovative Multi Vibrotactile-Skin Stretch (MuViSS) haptic device for sensory motor feedback from a robotic prosthetic hand

Abstract

In the field of upper limb prosthetics, the incorporation of sensory feedback is critical to cognitive processes and behavior. Studies have demonstrated that haptic feedback improves amputees’ control over their prostheses.

This study presents the development of the MuViSS (Multi Vibrotactile-Skin Stretch) haptic device, which is worn on the wrist and forearm and provides sensory-motor feedback from a robotic prosthetic hand. An innovative feedback strategy is presented that has not been explored in the existing literature. By combining two already established strategies – namely, stretching the skin in conjunction with proprioception and incorporating cues on contact – the research offers an unexplored approach to sensory feedback. Adaptations were made to a commercially available Taska prosthetic hand to integrate sensors and capture data for haptic feedback.

Two classes of tests performed on non-amputee subjects have shown promising efficacy and performance. A first class of tests, designed to assess the effectiveness of MuViSS feedback, was conducted with five participants, testing each feedback separately. In order to evaluate the effectiveness of the entire system, tests were also performed on nine subjects with MuViSS and the prosthetic hand being controlled. They allowed the comparison of the MuViSS feedback with the classical force feedback by vibration and with the condition without haptic feedback.

The results showed that the new feedback solution was able to provide size and stiffness information in the absence of vision. In addition, the feedback improved the performance of a motor task, specifically grasping a marble, with vision. The study demonstrates that the system has the potential to improve control, enhance performance, and positively impact the user’s overall experience when operating prosthetic devices.