Modelling temporal distribution of symptoms and diseases with fuzzy logic

Although there is no doubting the importance of a time factor in medical diagnosis, a formalisation of time-varying situations (in particular, using fuzzy set theory and fuzzy logic methods) for computer-assisted diagnosis systems presents a lot of open problems for investigators. While each time-varying situation can be conditionally separated into non-temporal and temporal components, both expressed with fuzzy sets, e.g. "high temperature early in the morning", the question is how to formalise these kinds of situations and to use them in the inferencing mechanisms of medical expert systems