Assistive mobility cane exploiting skin-stroke tactile haptic feedback mechanism for visually impaired persons

This study aims at providing assistive mobility to visually impaired persons through a proposed novel tactile haptic display of skin-stroke on ordinary cane's handle grip for avoiding obstacles in the path. For this purpose, the proposed ETA model has been designed to be accessible and easily mountable onto any ordinary cane due to its inherent modular structure. Additionally, it is aimed at detecting aerially suspended obstacles as well as moving objects in the path. Thus, a revamped design for vibrotactile haptic feedback ETA was also developed in order to test the proposed skin-stroke cane and the ordinary cane with it. In order to evaluate the proposed design's feasibility, it is tested with 5 blindfolded subjects and the experimental results show the comparison between the ordinary white cane, the proposed modification of a vibrotactile cane and the novel skin-stroke tactile haptic feedback cane. The purpose of this study is to find which one of the three canes delivers more intuitive perception of directions, adaptability, rate of least obstacle collision and preferred walking speed for the subjects. The proposed design comprises of: (1) an ultrasonic sensors' module, (2) a skin-stroke tactile haptic feedback mechanism on the handle grip of the cane to provide the rotational skin-stroking forces on the hand of the subjects. Also, the proposed study incorporates a rotating ultrasonic sensor for detecting overhanging, aerially suspended objects in front of the user, which is aimed at providing a more effective modification of the existing vibrotactile based ETAs.