Untangle the Web: Communicating Through the Web Services Using SemanticsAsuman DogacMETU, Turkey

The Interoperability Problem in the Healthcare DomainCan be investigated in the following categories:Interoperability of the healthcare messages exchanged (HL7 v3, HL7 v2, Proprietary messages)Interoperability of Electronic Healthcare Records (EHRs): HL7 CDA, CEN EHRcom, openEHRInteroperability of Coded Terms (ICD10, SNOMED, )Interoperability of Patient Identifiers, Healthcare Business Processes, Clinical Guide Lines,

Exchanging Messagesjohnsmith12345HL7-I12 Patient ReferralNetwork(e.g., VAN)11011010HL7-I12 Patient Referral12345smithjohn^^Application 1: HIS Database and back end applicationsApplication 2: HIS Database and back end applicationsInterface EngineInterface Engine

Ability to Communicate: Bits Running on the WiresTransport Protocols: TCP/IP, VANNetwork Protocols: HTTP, EDITransport Binding: Simple Object Access Protocol (SOAP) Web Services and ebXML messaging use SOAP HL7 approved Web Services and ebXML as DSTUIHE XDS uses ebXML

SOAP is Important

Why Use Web Services?Web services are application functions that can be programmatically invoked over the InternetAdvantages of Web services: They are supported by every major corporationThey have a flexible core language which is XML Two universally accepted standards: Web Services Description Language (WSDL), and,Simple Object Access Protocol (SOAP) Web services exploit the ubiquity and access simplicity of the Internet

The Use of Web Services in the Healthcare DomainIHE has developed Retrieve Information for Display (RID) Profile as a set of Web services

The Netherlands Institute for ICT in Healthcare (NICTIZ) has implemented the Dutch national infrastructure for healthcare messaging by wrapping HL7v3 messages as Web services

Also, Health Level Seven (HL7) has announced the approval of a Web Services Profile as Draft Standards for Trial Use (DSTUs) as Version 3 Transport Specifications within the HL7 Messaging Standard in May 2004

Communicating through Web Servicesjohnsmith12345

HL7-I12Patient Referral Web ServiceHTTP over TCP/IP11011010

HL7-I1212345smithjohn

Example: Deploying an Existing Application as Web ServiceRetrieveCriticalHealthcareData functionality of Care2xCare2x: A public domain HIS used in many countriesA Care2x SQL Query:SELECT *FROM care_encounter CE, WHERE CP.pid=patientpid

Example: Deploying an Existing Application as Web ServicePrepare the WSDL file:Determine operation, e.g., RetrieveCriticalHealthCareDataSpecify Input and Output ParametersSpecify how it will be accessed, i.e., transport binding like SOAPSpecify endpoint where the Web service will be deployed and invokedDeploy it to a Web Container

Example: Exposing Care2x RCHD as a Web ServiceSQL QuerySelect * From care_encounter CEWhere CE.pid=pid

Example: Invoking Care2x RCHD Web serviceSELECT * FROM care_encounter CEWHERE CE.pid=10000101RetrieveCriticalHealthcareDataWeb Service...10000101

Extracting and FormattingInformation10000101:intBuilding SQL Update QueryPatient Encounters:Result

Patient Encounter

Prepare Output MessageProcess Client RequestReturn Output MessageWebContainer

IHE Retrieve Information for Display (RID)Two Web services :Retrieve Specific Information:Patient centric: patient IDType of RequestDate, Time, nMostRecentRetrieve a DocumentObject Unique Instance Identifier (OID)Type of RequestContent Type Expected

IHE Retrieve Information for DisplayRetrieve Specific Info for DisplayTypes of RequestsSummary of All ReportsSummary of Laboratory ReportsSummary of Radiology ReportsSummary of Cardiology ReportsSummary of Surgery ReportsSummary of Intensive Care ReportsSummary of Emergency ReportsSummary of Discharge ReportsList of AllergiesList of Medications

Retrieve Document for DisplayPersistent DocumentIHE-RID WSDL

Functional InteroperabilityAbility of two or more applications to exchange information Achieved by fixing Network protocols such as Internet or Value Added Networks; The application protocols and transport bindings such as HTTP, FTP, SMTP and SOAP The message format like HL7v3What if applications use different message standards?

Interoperability of Message Standards

Semantic InteroperabilityAbility for information shared by systems to be understood through formally defined domain concepts

Annotating the information to be shared through ontologies and performing semantic mediation

How do we achieve semantic interoperability through Web services?Annotating Web service functionality through ontologiesAnnotating Web service messages through ontologiesAt the message schema level: Mapping disjoint but overlapping ontologies one into other At the message instance level: Using the mapping definition produced for automated mapping of message instances one into other

What is an Ontology?The word ontology comes from the Greek ontos (being) and logos (word)An ontology describes objects and concepts as classes These classes are arranged in a hierarchy, and then class attributes and relationships are described with propertiesClassSubclassSubclasspropertiespropertiesproperties

Why use an ontology?An Ontology provides: A common vocabulary: An ontology describes consensual knowledge, that is, it describes meaning which has been accepted by a group not by a single individual Ability to define relationships among classes, properties and instances Automated ProcessingQueryingReasoning

An Example Web Service Functionality OntologyHealthCareServicesPatient AdministrationPatient ReferralPatient CareObservationReportingSchedulingClinicalObservationReportingObservationReportingOfClinialTrialsResponseForClinicalObservationRequestForClinicalObservationRetrieveCriticalHealthDataserviceQualitylocationProperties of theGeneric ServiceClass

Semantic Mediation !

A Motivating ScenarioMr. John Smith is hospitalized with a cardiac episode at the Care2x HospitalPreviously, Mr. Smith had a Coronary artery bypass operation at the Istanbul Hospital The doctor at the Care2x Hospital wishes to retrieve Mr. Smiths Critical Health Data from Istanbul HospitalIstanbul Hospital uses HL7 v2.3 EDI messages and has exposed the critical healthcare data of its patients to the authorized users through semantically enriched Web servicesCare2x hospital, on the other hand, uses HL7 v3 XML messages.

First Problem: How to Handle Patient Identifiers?It is not feasible to maintain a master patient index for any two healthcare organization in the world that wish to communicate We have devised a mechanism to match the patient identifiers based on commonly available patient demographics described in: Eichelberg, M., Aden, T., Thoben, W.,"A Distributed Patient Identification Protocol based on Control Numbers with Semantic Annotation", Int'l Journal on Semantic Web & Information Systems, Vol. 1, No.4, October 2005.

HL7v2.3 EDI Message Sent by Istanbul Hospital

Semantic Mediation of Web Service MessagesC-Normalization EngineHL7 v2.3MessageSchema(XSD)NormalizationMapOWL WrapperRDFHL7 v2.3OntologyHL7 v2.3OntologyHL7 v3OntologyMappingDefinitionC-Normalization EngineOWL WrapperHL7 v3MessageSchema(XSD)RDFOWLHL7 v3OntologyNormalizationMapOWL

Additional Tools Used for creating HL7 v3 Message SchemasHL7 RoseTree Tool is used to create HL7 v3 messages

RoseTree allows the user to graphically build a HMD (Hierarchical Message Definition) from the HL7 v3 Reference Information Model

In order to translate the HMD to XSD, HL7 v3 Schema Generator Tool is used

Semantic MediationHL7 v2.3MessageSchema(XSD)HL7 v2.3Ontology NormalizationMapHL7 v2.3Message(EDI)HL7 v3MessageSchema(XSD)HL7 v3OntologyNormalizationMapEDI2XML ConverterD-Normalization EngineOWL WrapperXMLRDFHL7 v2.3Message(OWL)HL7 v3Message(OWL)HL7 v3Message(XML)MappingDefinitionHL7 v2.3Message(OWL)HL7 v3Message(OWL)D-Normalization EngineOWL WrapperRDF

Additional Tools Used for InstanceTransformationEDI to XML Conversion in HL7: HL7 Application Programming Interface (HAPI) Assembler/Disassembler Tool is used to transform the HL7 v2 EDI messages into their XML representations

Data Normalization Engine of the Harmonize project is used to transform XML Message instances to OWL instances

OWL Mapping Tool

An Example Mapping through OWLmtPersonRoleOrganizationAddrNameclassCodeNamePIDPDIXADXONPID.5.NameOrganization_NameSimilarToSimilarToSimilarTo

An Example Mapping through OWLmtDG1PulmonaryHypertensionwith extremeobesityDG1.4DG1.3CE27679008CE.1MessageActDiagnosisoutboundRelationshipDiagnosisSimilarToDataPropertyTransformactDiagnosisDescriptionactDiagnosisCodePrimary Pulmonary HypertensionI27.2DataPropertyTransform

HL7 v3 Message Received by the Care2x Hospital

I27.2 Primary Pulmonary Hypertension 93501 Right Hearth Catheterization

Important NoteWe are considering only the messages exchanged through a limited set of well-defined Web services!

Reasoning: An ExampleSNOMED27679008-Pulmonary Hypertension with extreme obesity

rdf:subClassOfSimilarityinstanceOfDG1-code:27679008instanceOfactDiagnosisCode:I27.2Mapping(rdf:subClassOf cls1 cls2)(rdf:type ind1 cls1) (rdf:type ind1 cls2)Ontology LevelInstance LevelInferred Info

ConclusionsWeb service based access and Semantic Mediation among healthcare institutes is becoming a reality

The technologies described have been implemented within the scope of the IST-2103 Artemis project funded by the European Commission

http://www.srdc.metu.edu.tr/webpage/projects/artemis/

Please come to booth 6147 to see a live demo of the technologies described!

ConclusionsCurrently, Artemis infrastructure is used to semantically mediate among different healthcare information systems of the end users of the project, namely, TEPE Technologies Corttex Hospital Information System (HIS),SEBT Paris system as well as the Care2x HIS

The source code of the OWL mapping tool described is publicly available at SourceForge, http://sourceforge.net/projects/owlmt

We are starting the RIDE Project supported by the European Commission which aims to develop a Roadmap for Interoperability of eHealth Systems for EU member states

Thank you very much for your attentionQuestions?