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UNIFIED MEDICAL LANGUAGE SYSTEMS (UMLS). The Unified Medical Language System (UMLS) is a long term research and development project that started in 1986 by the U.S. National Library of Medicine (NLM) The UMLS is not a gigantic and comprehensive medical vocabulary
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UNIFIED MEDICAL LANGUAGE SYSTEMS (UMLS) • The Unified Medical Language System (UMLS) is a long term research and development project that started in 1986 by the U.S. National Library of Medicine (NLM) • The UMLS is not a gigantic and comprehensive medical vocabulary • The UMLS is a relational database connecting “by concept” over 60 vocabularies, thesauri, medical problem lists etc.
Purpose • To aid the development of systems that help health professionals and researchers retrieve and integrate electronic biomedical information form a variety of sources, such as: • Computer-based Patient Records • Bibliographic databases • Factual (full text) databases • Administrative health data • Expert systems
UMLS Uses • Electronic patient records • Natural language processing • Information retrieval • Thesaurus construction • Automated indexing
UMLS COMPONENTS Metathesaurus Semantic Network Lexicon
UMLS Source “Vocabularies” • Widely varying purposes, structures, properties that do not add up to single ontology or view of the world: • Thesauri, e.g., MeSH (Medical Subject Headings) • Statistical Classifications, e.g., ICD • Billing Codes, e.g., CPT • Clinical coding systems, e.g., SNOMED • Lists of controlled terms, e.g., HL7 valid values
How to combine them? Not reallly ...
METATHESAURUS • Contains more than 60 vocabularies and classifications. • 776.940 concepts • 2,1 millions of concept names • 11 millions of relationships between concepts
Metathesaurus - Relations • Preserves the structure of the original sources. • Add news relationships between the concepts
Synonymous terms CUI Preferred term METATHESAURUS Organization
Metathesaurus structure CONCEPTs TERMs STRING CUI’s LUI’s SUI’s STRING Is organized by concept or meaning; its purpose is to link alternative names and views of the same concept together and to identify useful relationships between different concepts.. STRING STRING
Semantic Network • All information about specific concepts is found in the Metathesaurus • The Network provides information about the basic semantic types that are assigned to these concepts, and it defines the relationships that may hold between the semantic types • It defines these types, both with textual descriptions and by means of the information inherent in its hierarchies
Semantic Network Example “BIOLOGIC FUNTION” HIERARCHY EXPERIMENTAL MODEL OF DISEASE
LEXICON • It provide the lexical information needed for the SPECIALIST Natural Language Processing System • It is a general English lexicon that includes many biomedical terms (commonly occurring English words and biomedical vocabulary) • The lexicon entry for each word (or term) records the • syntactic • morphological • orthographic information needed by the SPECIALIST natural language processing system
UNIFIED MEDICAL LANGUAGE SYSTEM - Summary • Standard source of concepts and synonyms. • Multilingual • Broad extension. • Allow integration between applications
REFERENCES • http://www.nlm.nih.gov/pubs/factsheets/umls.html • http://www.nlm.nih.gov/research/umls/META2.HTML • http://www.nlm.nih.gov/research/umls/META3.HTML • http://www.nlm.nih.gov/research/umls/META4.HTML • http://www.nlm.nih.gov/pubs/cbm/umlscbm.html#6