Effect of vibrotactile feedback on robotic object manipulation

Recently there have been increased demands to improve function of prosthetic hands. One of the directions is implementation of force feedback to improve object manipulation. Previously we have employed vibrotactile stimulation to safely and non-invasively provide force feedback, showing that participants could improve task performance in a virtual environment. This work used robotic devices to develop a physical experimental environment to replace the previous virtual experimental conditions and to test the efficacy of vibrotactile feedback. Unimpaired participants (N6) were asked to drag a box to a target location. Performance of users was measured based on total box displacement, average box velocity, their subjective difficulty ratings, exerted power, and average applied normal force on the box. With vibrotactile feedback, participants were able to statistically significantly improve their task performance as measured by all parameters except average velocity. This result strongly supports the use of vibrotactile feedback as a simple methodology to provide force feedback to prosthetic hand users.