Disturbances of impulse formation: an expert system for ECG interpretation

This paper describes an expert system (ES) that aids in interpretation of some disturbances of impulse formation from electrocardiographic records. The system consists of a user interface, a knowledge base, an inference engine and an explanation facility. It is implemented using Turbo PROLOG and uses the built-in interpreter for goal proving or disproving. The user interface gets information about the case by interrogation through multiple choice or Yes/No questions. The response is processed and stored in a dynamic database. After the interview the processed data are stored in a permanent file for subsequent calls. The knowledge base contains domain rules of the If-Then variety. The inference engine supports the logic-based method of knowledge organization, which is controlled by backward-chaining. The explanation facility is able to give reasons for any fact in the dynamic database. The main diagnosis, the diagnostic criteria and the algorithm used are explained and illustrated with examples. Sample outputs of the system are also given.