ARTEMIS: A SEMANTIC WEB SERVICE-BASED P2P
IINFRASTRUCTURE FOR THE INTEROPERABILITY OF MEDICAL
A. Dogac, G. Laleci, Y. Kabak, V. Bicer, S. Unal, O. Gulderen
Software Research and Development Center
Middle East Technical University (METU), Turkiye
Interoperability is an important problem in the healthcare informatics domain since most of
the health information systems are proprietary. Interoperability can be addressed in two
Functional (syntactic) level interoperability is the ability of two or more systems to
exchange information. This involves agreeing on the common network protocols such
as Internet or Value Added Networks; the transport binding such as HTTP, FTP,
SMT, etc. and the message format like XML or EDI (Electronic Data Interchange).
Semantic level interoperability, on the other hand, is the ability for information shared
by systems to be understood at the level of formally defined domain concepts so that
the information is computer processable by the receiving system.
Currently the most promising functional interoperability technology is the Web Services.
Web services are application functions that can be programmatically invoked over the
Internet. The information that an application must have in order to programmatically invoke a
Web service is defined by two universally accepted standards: Web Services Description
Language (WSDL) and Simple Object Access Protocol (SOAP). WSDL of a Web service
defines its interface and establishes its public contract with the outside world. The network
protocol used is usually http and binding is SOAP. The importance of Web services in
providing functional interoperability has been recognized by the healthcare industry and
recently Integrating Healthcare Enterprise (IHE) initiative has proposed a set of Web services
for some of the basic functionality in healthcare information systems. Also HL7 has recently
approved Web services and ebXML standards as “draft standards for trial use”.
However for full machine interoperability we also need to define the semantic level
interoperability. In Web service technology this translates to describing the semantics of Web
services. Semantics is domain specific knowledge and medical informatics is one of the few
domains to have considerable domain knowledge exposed through standards.
The talk will describe the architecture of the Artemis project, which exploits ontologies based
on the domain knowledge exposed by the healthcare information standards like HL7, CEN
TC251, ISO TC215 and GEHR. I will explain how these standards can be used in expressing
the semantics of both the functionality of Web services (i.e., what a Web service does) and
the semantics of the messages they exchange. Artemis interoperability architecture does not
propose globally agreed ontologies; rather healthcare institutes reconcile their semantic
differences through a mediator component. The mediator component uses ontologies based
on prominent healthcare standards as references to facilitate semantic mediation among
involved institutes. Artemis mediators have a Peer-to-Peer communication architecture to
provide scalability and to facilitate the discovery of other mediators.
Keywords: Healthcare, Semantic Web, Web Services, Peer-to-Peer