Ontology-based Personalized Wayfinding System Using Deviation Detecting for Individuals with Cognitive Impairments

According to psychological model of spatial navigation and the requirements of rehabilitation professionals, PDAs prompting with spatial photos at the right time and place can assist cognitively-impaired persons with navigating indoors or on the road. Passive RFID tags which can be imagined as a new traffic sign system, are posted to selected positions on routes. The navigational photos are served on demand to the user who uses the built-in RFID reader to sense the tag when it is in eyesight range. Ontology-based route personalization is proposed to adapt routes with respect to context and changing environment. A tracking function is integrated with a time constrained breadth-first search at the core of deviation detecting algorithm. The tracking system increases the sense of security and also lowers the entry threshold to accepting the assistive technology.