A Haptic Solution to Assist Visually Impaired in Mobility Tasks

Electronic travel aids are used for detecting obstacles, identifying services, and, generally, obtaining useful information from the surroundings, thus enabling a safe and effective exploitation of the environment. A drawback is unnatural codification, which may lead to usability concerns. This paper introduces a haptic device aimed to provide the user with information on the presence of obstacles inside the environment. The haptic interface is intended to reproduce the stimuli provided by a traditional white cane, without any contact with the environment. A prototype, implemented through a short cane with an embedded smart sensing strategy and an active handle, is presented. Twenty-five blindfolded normally sighted users participated to assess system performance in detecting obstacles and correctly conveying their position by the haptic interface. With respect to detecting obstacles and their positions, the average values of the sensitivity in the case of left, center, and right positioned obstacles are 0.735, 0.803, and 0.830, while the specificity values are 0.924, 0.835, and 0.827, respectively.