A Qualitative and Quantitative Analysis of Research in Mobility Technologies for Visually Impaired People

Assistive technology in rehabilitation programs is vital for people with vision impairments worldwide. The term "blind assistive technology" refers to mobility devices specifically designed to provide position, orientation and mobility assistance for visually impaired individuals during indoor and outdoor activities. The paper presents a comprehensive evaluation of 140 research articles published over the past 75 years (1946 to 2022). This research analyses the evolution of assistive technology aids in depth, in terms sensing technique followed, algorithms employed for obstacle detection, localization, object recognition, depth estimation and scene understanding. It also includes, the functional attributes of the aid, feedback type, and assistive solutions embedded in aid. It evaluates the assistive aids for their usability index, portability, battery life, feedback type, and aesthetics. The survey findings reveal that optical and sonic sensor-based aids prioritize speed, weight, and battery life but lack major functionalities, achieving an average performance score of 62%. Stereo, monocular, SLAM, and 3-D point cloud-based aids excel in obstacle distance estimation and avoidance but require greater memory resources, with a lower performance score of 41%. Artificial intelligence and cloud-based aids offer comprehensive scene details but demand complex computational capabilities, achieving a performance score of 44%. However, the most suitable technology for developing state-of-the-art solutions for blind individuals is the multisensor fusion-based and guide robot-based aids, providing a majority of the essential assistive functions with a performance score of 51%. The study highlights possible challenges associated with implementing assistive technology aids, emphasizes the importance of user acceptability, and stresses the need for real-time evaluation of blind aids. The paper lays a concrete foundation and direction for future development, emphasizing the critical challenges faced by blind users, including boarding trains, traveling on public transport, shopping in a supermarket, avoiding dynamic obstacles, and real-time understanding of the surrounding scene. Addressing these key concerns is crucial for the continued development and improvement of assistive technology aids for the visually impaired, leading to enhanced independence, mobility, and ultimately, a higher quality of life.