Abstract
Providing semantic interoperability is a current challenge in the field of data integration. In healthcare environments, sharing information may be essential to ensure a good treatment to the patient. In addition, it is necessary to ensure the accuracy of the data that is being exchanged. In this paper we present the design and implementation of an ontology for the patient clinical evolution record, using the UMLS semantic network as an upper-level ontology, based on a clinical data structure. We show how our ontology can be used as a semantic connection between two distinct health databases in their data integration process.