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Biomedical subjects

A T McCray

Publications and source records attributed to A T McCray.

12 recordsLinked to original sources
PubMed1996

The UMLS Knowledge Source Server: a versatile Internet-based research tool.

The National Library of Medicine's Unified Medical Language System (UMLS) project regularly distributes a set of Knowledge Sources to the research community. In 1995 the UMLS data were made available for the first time through the Internet-based UMLS Knowledge Source Server. The server can be accessed through three different client interfaces. The World Wide Web interface allows users to browse and explore the data and to see how those data are organized in the UMLS. The command-line interface is best suited for batch processing, and the application programming interface allows developers at remote sites to embed calls in their application programs to the Knowledge Source Server.

Computer Communication Networks↗
PubMed1995

ASN.1: defining a grammar for the UMLS knowledge sources.

The unified Medical Language System (UMLS) project provides resources on an experimental basis to the research community. In 1995 the four UMLS Knowledge Sources have been provided in an additional data format, Abstract Syntax Notation One (ASN.1). The benefits of ASN.1 are that it provides a standard, formal grammar for complex data and allows exchange of that data in a way which is independent of the particular software and hardware environment in which the data are created and stored. The paper begins with an introduction to the ASN.1 standard itself. It continues with a discussion of the ASN.1 implementation of the UMLS Knowledge Sources and some of the consequences for the newly released UMLS Knowledge Source Server. It concludes with a discussion of some of the benefits of using ASN.1 encoded data.

Computer Communication Networks↗
PubMed1995

The UMLS Knowledge Source server.

The UMLS Knowledge Source server is an evolving tool for accessing information stored in the UMLS Knowledge Sources. The system architecture is based on the client-server paradigm wherein remote site users send their requests to a centrally managed server at the U.S. National Library of Medicine. The client programs can run on platforms supporting the TCP/IP communication protocol. Access to the system is provided through a command-line interface and through an Application Programming Interface.

Computer Communication Networks↗
PubMed1995

The representation of meaning in the UMLS.

The UMLS knowledge sources provide detailed information about biomedical naming systems and databases. The Metathesaurus contains biomedical terminology from an increasing number of biomedical thesauri, and the Semantic Network provides a structure that encompasses and unifies the thesauri that are included in the Metathesaurus. This paper addresses some fundamental principles underlying the design and development of the Metathesaurus and Semantic Network. It begins with a description of the formal properties of thesauri, including the Metathesaurus, and the formal properties of the Semantic Network. It continues with consideration of the principle of semantic locality and how this is reflected in the UMLS knowledge sources. The paper concludes with a discussion of the issues involved in attempting to re-use knowledge and the potential for re-use of the UMLS knowledge sources.

Artificial Intelligence↗
PubMed1994

Lexical methods for managing variation in biomedical terminologies.

Access to biomedical terminologies is hampered by the high degree of variability inherent in natural language terms and in the terminologies themselves. The lexicon, lexical programs, databases, and indexes included with the 1994 release of the UMLS Knowledge Sources are designed to help users manage this variability. We describe these resources and illustrate their flexibility and usefulness in providing enhanced access to data in the UMLS Metathesaurus.

Biology↗
PubMed1993

The Unified Medical Language System.

In 1986, the National Library of Medicine began a long-term research and development project to build the Unified Medical Language System (UMLS). The purpose of the UMLS is to improve the ability of computer programs to "understand" the biomedical meaning in user inquiries and to use this understanding to retrieve and integrate relevant machine-readable information for users. Underlying the UMLS effort is the assumption that timely access to accurate and up-to-date information will improve decision making and ultimately the quality of patient care and research. The development of the UMLS is a distributed national experiment with a strong element of international collaboration. The general strategy is to develop UMLS components through a series of successive approximations of the capabilities ultimately desired. Three experimental Knowledge Sources, the Metathesaurus, the Semantic Network, and the Information Sources Map have been developed and are distributed annually to interested researchers, many of whom have tested and evaluated them in a range of applications. The UMLS project and current developments in high-speed, high-capacity international networks are converging in ways that have great potential for enhancing access to biomedical information.

Information Storage and Retrieval↗
PubMed1993

UMLS knowledge for biomedical language processing.

This paper describes efforts to provide access to the free text in biomedical databases. The focus of the effort is the development of SPECIALIST, an experimental natural language processing system for the biomedical domain. The system includes a broad coverage parser supported by a large lexicon, modules that provide access to the extensive Unified Medical Language System (UMLS) Knowledge Sources, and a retrieval module that permits experiments in information retrieval. The UMLS Metathesaurus and Semantic Network provide a rich source of biomedical concepts and their interrelationships. Investigations have been conducted to determine the type of information required to effect a map between the language of queries and the language of relevant documents. Mappings are never straightforward and often involve multiple inferences.

Humans↗
PubMed1991

Extending a natural language parser with UMLS knowledge.

Over the past several years our research efforts have been directed toward the identification of natural language processing methods and techniques for improving access to biomedical information stored in computerized form. To provide a testing ground for some of these ideas we have undertaken the development of SPECIALIST, a prototype system for parsing and accessing biomedical text. The system includes linguistic and biomedical knowledge. Linguistic knowledge involves rules and facts about the grammar of the language. Biomedical knowledge involves rules and facts about the domain of biomedicine. The UMLS knowledge sources, Meta-1 and the Semantic Network, as well as the UMLS test collection, have recently contributed to the development of the SPECIALIST system.

Information Storage and Retrieval↗
PubMed1990

Automated access to a large medical dictionary: online assistance for research and application in natural language processing.

Online dictionaries can be important tools for research and application in natural language processing. This paper describes work with a machine-readable version of "Dorland's Illustrated Medical Dictionary". First the characteristics of the dictionary are briefly described, and then the complex process of converting the tape to an online interactive dictionary is discussed. The results of several experiments in automatically deriving information from the online dictionary are presented, and the paper ends with a discussion of the use of the online dictionary as a tool in the development of a natural language processing system designed for the biomedical domain.

Abstracting and Indexing↗
PubMedDate not supplied

Planned NLM/AHCPR large-scale vocabulary test: using UMLS technology to determine the extent to which controlled vocabularies cover terminology needed for health care and public health.

The National Library of Medicine (NLM) and the Agency for Health Care Policy and Research (AHCPR) are sponsoring a test to determine the extent to which a combination of existing health-related terminologies covers vocabulary needed in health information systems. The test vocabularies are the 30 that are fully or partially represented in the 1996 edition of the Unified Medical Language System (UMLS) Metathesaurus, plus three planned additions: the portions of SNOMED International not in the 1996 Metathesaurus Read Clinical Classification, and the Logical Observations Identifiers, Names, and Codes (LOINC) system. These vocabularies are available to testers through a special interface to the Internet-based UMLS Knowledge Source Server. The test will determine the ability of the test vocabularies to serve as a source of controlled vocabulary for health data systems and applications. It should provide the basis for realistic resource estimates for developing and maintaining a comprehensive "standard" health vocabulary that is based on existing terminologies.

Computer Communication Networks↗