Recent advancements in indoor electronic travel aids for the blind or visually impaired: a comprehensive review of technologies and implementations

The human sense of vision is a critical tool for interaction and exploration in the physical world. However, this valuable faculty can be impaired by a range of causes, such as congenital disabilities, accidents, or illnesses. Blind or visually impaired persons (BVIP) face considerable challenges in navigation, especially in unfamiliar settings, impeding their autonomy and exposing them to potential hazards. Electronic travel aids (ETAs) have emerged as a solution, providing support for mobility and facilitating autonomous navigation through information on the environment, the user's location, and directional instructions. Despite the existence of these systems, the literature lacks a comprehensive approach to integrating various functions into ETAs to enhance their support of indoor navigation activities for BVIP. This systematic literature review analysed previous ETAs and evaluated them based on the technologies employed and the functions they fulfil. A thorough search was conducted across ten journal databases, focusing on articles published between 2017 and 2022 to capture the most recent advancements in related ETA technologies. The results of this review highlight a promising avenue for future research in developing advanced ETAs for indoor navigation by BVIP.