Developing a UMLS-based Ontology of Cardiology Procedures for Cognitive Support in Medical Decision Making

Modularity of mental processes is a structural and functional characteristic of their organizational complexity. Medical reasoning and decision making are conducted in specific, parallel and interconnected process levels. Ontology is a formal conceptualization of a particular knowledge about the world, through the explicit representation of basic concepts, relations, and inference rules about themselves. Domain ontologies can be used to provide knowledge support in underlying cognitive processes and inter-relations, and a methodology for connecting databases and facilitating professional communication, by supplying added-value information about structural and logical properties of the modeled conceptual network. An ontology of the cardiology procedure domain was developed, based on information provided by the Unified Medical Language System. Both intensional and extensional dimensions of UMLS concepts were taken into consideration. Semantic contents of cardiology procedure concepts definitions, and conceptual relations in the Metathesaurus and the Semantic Network were used in the research, with additional information provided by MeSH Journal Descriptors. Two methods were used for defining the subset of cardiology concepts, one lexical-based and another hierarchical-based. The resulting set was revised to exclude concepts not strictly pertinent to the specific study domain. The final definition set was submitted to natural language processing, analyzing phrases according to their basic elements and mapping the component concepts to UMLS ‘Semantic Types’. Conceptual categories were generated, and populated with the concepts, by using both a topdown and a bottom-up approach, and by defining a meronymic compositional structure for representing domain knowledge. Relations between classes were defined, according to two approaches, a formal-rationalistic and an empirical one. Tools used for developing the research consisted in a DBMS, the MetaMap, the Semantic Navigator, the Protégé platform for ontology development, and a graphic design tool. The methodology used for developing the work will be presented, as well as the produced results. These will be displayed in the specific developed taxonomy, and in Sowa’s Conceptual Graphs to represent some of the associative relations.