Use of general-purpose negation detection to augment concept indexing of medical documents: a quantitative study using the UMLS.

ABSTRACT:

Objectives

To test the hypothesis that most instances of negated concepts in dictated medical documents can be detected by a strategy that relies on tools developed for the parsing of formal (computer) languages-specifically, a lexical scanner ("lexer") that uses regular expressions to generate a finite state machine, and a parser that relies on a restricted subset of context-free grammars, known as LALR(1) grammars.

Methods

A diverse training set of 40 medical documents from a variety of specialties was manually inspected and used to develop a program (Negfinder) that contained rules to recognize a large set of negated patterns occurring in the text. Negfinder's lexer and parser were developed using tools normally used to generate programming language compilers. The input t

SUBMITTER: Mutalik PG 

PROVIDER: S-EPMC130070 | biostudies-literature | 2001 Nov-Dec

REPOSITORIES: biostudies-literature