database implementing CORBAmed's Lexicon Query ... - Europe PMC

Graphical navigation of the UMLS meta-thesaurus on a locally installed database implementing CORBAmed's Lexicon Query Service Thomas Frankewitsch, M.D., Ulrich Prokosch, Ph.D. Department of Medical Informatics and Biomathematics, University of Muenster, Germany Introduction: In 1998 the CORBAmed division of the Object Management Group (OMG) released one of their first definitions of medical information services: the lexicon query services (LQS).1 One of the basic intentions of the LQS is to support browsing by querying the terminology services to determine the structure and meaning of a terminology system.2 Because of the requirement for navigating and manipulating the vocabulary both in concepts and relations between existing concepts, graphical tools have been developed based on this standard. Methods: Using an Oracle8i database a locally installed copy of the Unified Medical Language System's (UMLS) meta-thesaurus serves as a repository for a structured description of medical multi-media data.3 Implementing an entity-attribute-value (EAV) construct in database design provides a high flexibility and scalability.4 Since querying databases with SQL usually results in a table-oriented design, lacking in clarity to understand the hierarchies in semantic networks, the "node and arc"-design seems to be more adequate. On this background an explorer-like graphical user interface has been realized (see figure 1). The CORBAmed interface definition language (IDL) specification defines a huge amount of services, but only demands a little subset as basis. Within this project the "LexExplorer interface" has been implemented. "JacORB" is used as the underlying object request broker (ORB), which is freely available and completely written in JAVA, developed at the Free University of Berlin.5 Discussion: A controlled and inter-application-wide valid data dictionary is required in almost all medical applications and all medical institutions. In our project we have shown that with the use of an additional graphical user interface it is possible to import such a database for the needs of nearly any institution and specific task. The tree representation offers a detailed view of intercomnections between concepts on a commonly accepted design pattern. The CORBA implementation of the client-sever interaction offers more flexibility for combining multiple programs, but needs more time for implementation and tuning. For example compiled

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interfaces and methods Ph&_p - CHb of CORBA from different vendors are not fully. compatible with each other. Therefore, the real ; cd integration of different. i*30 COrlUILSS CORBA systems has to be proved within medical ,, s. c environments. iidul But the LQS is designed *+1 Radia. SubeMer for navigation and not a1 &ujl_ for inserting concepts. j~>' Cd Nudleu Consequently we had to implement an additional tool for manipulating our dictionary, which works F 2gure 1:To n axon on the database directly, using an ODBC-bridge. Another problem is the central and distributed definition of concepts in one repository. Defining a well designed index pattem, which distinguishes between local and central data, allows the modified mirroring of a central vocabulary: Using the central one (UMLS) but extending it according the needs of the local environment offers the opportunity of a rich thesaurus and the maximnm of flexibility. Acknowledgement This work has been funded by the medical faculty of the university of Muenster, Germany, within the project "innovative researches in medicine" (Project Fi-l-2-II/96-17), within the HSP-fI program of the "Ministry for schools, higher education, science and research of the state of North Rhine-Westphalia" and by SUN

Microsystems. References 1. http://www.omg.org/cgi-bin/doc?corbamed/98-03-22.doc; available: 11.01.2000 2. Wang C, Ohe K. A CORBA-based object framework with patient identification translation and dynamic linking. Methods for exchanging patient data. Methods Inf Med 1999; 38(1):56-65. 3. Frankewitsch T, Prokosch U. Multimedia explorer. image database, image proxy-server and search-engine. Proc AMIA Symp 1999;765-769. 4. Nadkami PM, Marenco L, Chen R, Skoufos E, Shepherd G, Miller P. Organization of heterogeneous scientific data using the EAV/CR representation. J Am Med Inform Assoc 1999; 6(6):478-493. 5. Brose G, Bokowski B. Ein Object Request Broker fur Java. Infonnatik/Informatique 1997; 3:27-30.

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