The Unified Medical Language System (UMLS)
UMLS is a system designed by the National Library of Medicine (NLM) to help health professionals and researchers retrieve and integrate electronic biomedical information from a variety of sources. It combines many well-established authoritative medical informatics terminologies in one knowledge representation system. UMLS contains a metathesaurus with medical concepts and a semantic network. It is a consolidated repository of medical terms and their relationships. Each biological concept in UMLS is associated with semantic classes.
"Designed initially by Donald Lindberg, M.D., Director of the US National Library of Medicine in 1986, the Unified Medical Language System (UMLS) is a controlled compendium of many vocabularies which also provides a mapping structure between them. The UMLS is composed of three main knowledge components: Metathesaurus®, Semantic Network and SPECIALIST Lexicon. " (Wikipedia, 2006).
"UMLS (Unified Medical Language System) is a system designed by the National Library of Medicine (NLM) to help health professionals and researchers retrieve and integrate electronic biomedical information from a variety of bibliographic databases, factual databases, and expert systems." (National Committee on Vital and Health Statistics. 2000).
Srinivasan (1999) writes that the Unified Medical Language System (UMLS) has a unique and leading position in the evolution of thesauri and metathesauri. Features that set it apart are: its composition from more than fifty component health care vocabularies; the sophisticated UMLS ontology linking the Metathesaurus with structures such as the Semantic Network and the SPECIALIST lexicon; and the high level of social collaboration invested in its construction and growth. It is our thesis that in order to successfully harness such a complex vocabulary for text retrieval we need sophisticated methods derived from a deeper understanding of the UMLS system. Thus we propose a theoretical framework based on the theory of rough sets, that supports the systematic and exploratory investigation of the UMLS Metathesaurus for text retrieval. Our goal is to make it more feasible for individuals such as patients and health care professionals to access relevant information at the point of need.
Gu et al. (2000) found that the UMLS is very large and complex and poses serious comprehension problems for users and maintenance personnel. The authors present a representation to support the user's comprehension and navigation of the UMLS. An object-oriented database (OODB) representation is used to represent the two major components of the UMLS—the Metathesaurus and the Semantic Network—as a unified system. The semantic types of the Semantic Network are modeled as semantic type classes. Intersection classes are defined to model concepts of multiple semantic types, which are removed from the semantic type classes. The authors provide examples of how the intersection classes help expose omission of: concepts, highlight errors of semantic type classification and uncover ambiguities of concepts in the UMLS. The resulting UMLS OODB schema is deeper and more refined than the Semantic Network, since intersection classes are introduced. The Metathesaurus is classified into more mutually exclusive, uniform sets of concepts. The scheme improves the user's comprehension and navigation of the Metathesaurus.
Literature:
Gu, H. Y.; Perl, Y.; Geller, J.; Halper, M.; Liu, L. M. & Cimino, J. J. (2000). Representing the UMLS as an object-oriented database: Modeling issues and advantages. Journal of the American Medical Informatics Association, 7(1), 66-80.
National Committee on Vital and Health Statistics. 2000. Report on Uniform Data Standards for Patient Medical Record Information. Available at: http://ncvhs.hhs.gov/hipaa000706.pdf
Srinivasan, P. (1999). Exploring the UMLS: A rough sets based theoretical framework. Journal of the American Medical Informatics Association, S, 156-160.
Wikipedia. The free encyclopedia. (2006). Unified Medical Language System. http://en.wikipedia.org/wiki/Unified_Medical_Language_System
See also: Medicine; Metathesauri;
Birger Hjørland
Last edited: 10-09-2006