Enhancing grasping ability with vibrational guidance for individuals who are blind or partially sighted

Abstract

Abstract This study investigates the effectiveness of a vibrotactile bracelet in supporting goal-directed hand movements and grasping tasks for visually conditioned individuals. The research addresses the challenge of object manipulation without visual feedback, comparing tactile to auditory cues. The primary research question explores whether vibrotactile signals delivered via a wrist-worn device can accurately guide hand movements and improve grasping precision. Forty-one participants with varying degrees of limited vision completed a localization task and a grasping task under tactile and auditory guidance conditions and filled out a questionnaire featuring Likert scale items and open-ended questions. The results revealed a mean localization accuracy of 90.6% for vibrotactile signals, with some confusion between neighboring directions. In the grasping task, auditory feedback elicited quicker response times, yet 15 participants exhibited superior performance with tactile feedback. Factor analysis of participant feedback uncovered three key dimensions: confidence, comfort, and learning. Qualitative analysis underscored the need for customizable vibration intensity, enhanced precision, and ergonomic design. Findings suggest that vibrotactile feedback, while slightly slower than auditory cues, is a promising, alternative for supporting grasping without interfering with auditory awareness. Improvements in device design and personalized calibration could enhance its practical application, contributing to greater independence for visually conditioned individuals.