A novel mixed reality assistive system to aid the visually and mobility impaired using a multimodal feedback system

Most of the people affected by vision impairments are over 50 years old, which amplifies cognitive impairments and the risk of falling. This paper proposes a mixed reality assistive system to aid the navigation of visually impaired people by using a Smart Walker, audio feedback to provide cues to be followed, and vibratory feedback to indicate obstacles. To validate this system, 24 volunteers participated of three tasks consisting in a combination of a control strategy (Free Roam, Steering-Assisted Navigation, and Virtual Trail) and a path. To evaluate the experiments, task performance metrics and three questionnaires (Quality of Experience, SUS, and NASA-TLX) were assessed. According to SUS, all control strategies scored above 70, indicating their acceptability. Analyzing and comparing the questionnaires results and the strategies used, the Steering-Assisted Navigation, in which the volunteers had to follow a path indicated only by the haptic feedback provided by the controller, was the most physically and mentally demanding. The other two strategies required less effort, physical, and mental demand. Despite requiring different cognitive loads for navigation, all control strategies combined with the multimodal sensory feedback guided the volunteers during the tasks, evidencing the feasibility of the system.