Identifying Relations between Medical Concepts by Parsing UMLS^® Definitions

Abstract

To automatically analyse medical narratives, one needs linguistic and conceptual resources which support capturing of important information from texts and its representation in a structured way. Thus the conceptual structures encoding domain concepts and relations are crucial for the development of reliable and high-performance information extraction system. We present research work enabling automatic extraction of relations between medical concepts. The lack of conceptual resources with Bulgarian ontological vocabulary provoked us to reuse already existing resources with English labels, more especially the UMLS^®  Metathesaurus^®. We form a terminological dictionary of the Bulgarian terms of interest, translate them to English and extract their UMLS definitions which are short English statements in free text. These definitions are processed automatically by a semantic parser; afterwards we apply additional extraction, alternation and validation rules and built a set of new relations to be inserted in our conceptual resource. The article presents the input data and available tools, the knowledge chunks extracted from UMLS and their processing, as well as a discussion of the present results.