The Design of a "Functional" Database System and its use in the Management of the Critically III

This paper reports on the design and implementation of the database used in the Quantitative Sentinal, a commercial patient data management system. This system was designed and has been in clinical use at the Maryland Institute for Emergecy Medical Services Systems, in Baltimore, Maryland, for over 5 years. The system has also been installed at several other medical facilities throughout the United States and Canada. The report emphasizes a "model" for clinical information which describes clinical data as a collection of discrete value functions with certain properties. A database design based on the "functional" model is described. Typical data accesses of the database are examined in relationship to sample clinical questions. Within the implementation discussion, a special emphasis on database redundancy is also provided.