Fuzzy temporal constraint networks for clinical information.

Modeling the temporal information in the medical record is an important area of research. This paper describes an extension of TimeText, a temporal reasoning system designed to represent, extract, and reason about temporal information in clinical text, to include the use of fuzzy temporal constraints. The addition of fuzzy temporal constraints increases TimeTexts ability to handle uncertainty in temporal relations. We use a three-state, staircase possibility distribution function in conjunction with earlier methods of finding solutions to fuzzy temporal constraint networks. We perform analysis to determine the complexity of using this staircase in conjunction with finding solutions to fuzzy temporal constraint satisfaction problems and show that these solutions can be efficiently computed in O(n3).