A Codasyl-Type Schema for Natural Language Medical Records
Naomi Sager, Leo Joseph Tick, Guy Story, Lynette Hirschman · PubMed Central · 1980
This paper describes a CODASYL (network) database schema for information derived from narrative clinical reports. The goal of this work is to create an automated process that accepts natural language documents as input and maps this information into a database of a type managed by existing database management systems. The schema described here represents the medical events and facts identified through the natural language processing. This processing decomposes each narrative into a set of elementary assertions, represented as MEDFACT records in the database. Each assertion in turn consists of a subject and a predicate classed according to a limited number of medical event types, e.g., signs/symptoms, laboratory tests, etc. The subject and predicate are represented by EVENT records which are owned by the MEDFACT record associated with the assertion. The CODASYL-type network structure was found to be suitable for expressing most of the relations needed to represent the natural language information. However, special mechanisms were developed for storing the time relations between EVENT records and for recording connections (such as causality) between certain MEDFACT records. This schema has been implemented using the UNIVAC DMS-1100 DBMS.