An AI-based communication system for motor and speech disabled persons: design methodology and prototype testing

An intelligent communication device is developed to assist nonverbal, motor-disabled persons in the generation of written and spoken messages. The device is centered on a knowledge base of the grammatical rules and message elements. A belief reasoning scheme based on both the information from external sources and the embedded knowledge is used to optimize the process of message search. The search for the message elements is conceptualized as a path search in the language graph, and a special frame architecture is used to construct and to partition the graph. Bayesian belief reasoning from the Dempster-Shafer theory of evidence is augmented to cope with time-varying evidence. An information fusion strategy is also introduced to integrate various forms of external information. Experimental testing of the prototype system is discussed.