Untangle the Web: Communicating Through the Web Services Using Semantics

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Untangle the Web Communicating Through the Web
Services Using Semantics

• Asuman Dogac
• METU, Turkey

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The Interoperability Problem in the Healthcare
Domain

• Can 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, openEHR
• Interoperability of Coded Terms (ICD10, SNOMED,
  )
• Interoperability of Patient Identifiers,
  Healthcare Business Processes, Clinical Guide
  Lines,

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Exchanging Messages
Interface Engine
Interface Engine
Transmitting
HL7-I12 Patient Referral
HL7-I12 Patient Referral


12345
smith
john
11011010
Network (e.g., VAN)
12345
smith
john
Application 1 HIS Database and back end
applications
Application 2 HIS Database and back end
applications
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Ability to Communicate Bits Running on the Wires

• Transport Protocols TCP/IP, VAN
• Network Protocols HTTP, EDI
• Transport Binding Simple Object Access Protocol
  (SOAP)
• Web Services and ebXML messaging use SOAP
• HL7 approved Web Services and ebXML as DSTU
• IHE XDS uses ebXML

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SOAP is Important
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Why Use Web Services?

• Web services are application functions that can
  be programmatically invoked over the Internet
• Advantages of Web services
• They are supported by every major corporation
• They 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

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The Use of Web Services in the Healthcare Domain

• IHE 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

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Communicating through Web Services
Processing
Processing
Transmitting
HL7-I12
Patient Referral Web Service
HL7-I12
ltpatientgt
ltpatientgt
ltidgt
lt/idgt
ltidgt
lt/idgt
12345
ltnamegt
ltnamegt
john
lt/namegt
lt/namegt
ltsurnamegt
ltsurnamegt
smith
11011010
lt/surnamegt
lt/surnamegt
lt/patientgt
lt/patientgt
HTTP over TCP/IP
12345
smith
john
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Example Deploying an Existing Application as Web
Service

• RetrieveCriticalHealthcareData functionality of
  Care2x
• Care2x A public domain HIS used in many
  countries
• A Care2x SQL Query
• SELECT
• FROM care_encounter CE,
• WHERE CP.pidpatientpid

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Example Deploying an Existing Application as Web
Service

• Prepare the WSDL file
• Determine operation, e.g., RetrieveCriticalHealthC
  areData
• Specify Input and Output Parameters
• Specify how it will be accessed, i.e., transport
  binding like SOAP
• Specify endpoint where the Web service will be
  deployed and invoked
• Deploy it to a Web Container

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Example Exposing Care2x RCHD as a Web Service
Care2X Web Interface
SQL Query Select From care_encounter CE Where
CE.pidpid
Client
Care2X Retrieve Critical Healthcare Data Web
Service
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Example Invoking Care2x RCHD Web service
Extracting and Formatting Information
Process Client Request
ltRCHDInputMessagegt... ltlocalPatientIDgt10000101 lt/l
ocalPatientIDgt
Web Container
RetrieveCriticalHealthcareData Web Service
Building SQL Update Query
10000101int
Return Output Message
SELECT FROM care_encounter CE WHERE
CE.pid10000101
ltRCHDOutputMessagegt ltresultgtPatient
Encounterlt/resultgt lt/APOutputMessagegt
Prepare Output Message
Patient EncountersResult
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IHE Retrieve Information for Display (RID)

• Two Web services
• Retrieve Specific Information
• Patient centric patient ID
• Type of Request
• Date, Time, nMostRecent
• Retrieve a Document
• Object Unique Instance Identifier (OID)
• Type of Request
• Content Type Expected

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IHE Retrieve Information for Display
Persistent Document

• Types of Requests
• Summary of All Reports
• Summary of Laboratory Reports
• Summary of Radiology Reports
• Summary of Cardiology Reports
• Summary of Surgery Reports
• Summary of Intensive Care Reports
• Summary of Emergency Reports
• Summary of Discharge Reports
• List of Allergies
• List of Medications

Retrieve Specific Info for Display
Retrieve Document for Display
IHE-RID WSDL lt?xml version"1.0"
encoding"utf8"?gt ltdefinitions xmlnshttp"http//
schemas.xmlsoap.org/wsdl/http/"
xmlnss"http//www.w3.org/2001/XMLSchema"
xmlnss0"http//rsna.org/ihe/IHERetrieveForDispla
y" targetNamespace"http//rsna.org/ihe/IHERetriev
eForDisplay" xmlns"http//schemas.xmlsoap.org/wsd
l/"gt lttypesgt ltsschema elementFormDefault"qualifi
ed" targetNamespace"http//rsna.org/ihe/IHERetrie
veForDisplay"gt ltssimpleType name"summaryRequest
Type"gt ltsrestriction base"sstring"gt
ltsenumeration value"SUMMARY" /gt
ltsenumeration value"SUMMARY-RADIOLOGY" /gt
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Functional Interoperability

• Ability 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 HL7v3
• What if applications use different message
  standards?

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Interoperability of Message Standards
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Semantic Interoperability

• Ability 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

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How do we achieve semantic interoperability
through Web services?

• Annotating Web service functionality through
  ontologies
• Annotating Web service messages through
  ontologies
• At 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

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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 properties

Class
properties
Subclass
Subclass
properties
properties
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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 Processing
• Querying
• Reasoning

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An Example Web Service Functionality Ontology
HealthCareServices
Patient Administration
Patient Referral
ObservationReporting
Patient Care
Scheduling
ClinicalObservationReporting
ObservationReportingOfClinialTrials
ResponseForClinicalObservation
RequestForClinicalObservation
RetrieveCriticalHealthData
Properties of the Generic Service Class
serviceQuality
location
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Semantic Mediation ?!
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A Motivating Scenario

• Mr. John Smith is hospitalized with a cardiac
  episode at the Care2x Hospital
• Previously, 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 Hospital
• Istanbul 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 services
• Care2x hospital, on the other hand, uses HL7 v3
  XML messages.

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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.

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HL7v2.3 EDI Message Sent by Istanbul Hospital
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Semantic Mediation of Web Service Messages
C-Normalization Engine
HL7 v2.3 Message Schema (XSD)
Normalization Map
HL7 v2.3 Ontology
RDF
OWL
OWL Wrapper
HL7 v2.3 Ontology
HL7 v3 Ontology
Mapping Definition
OWL Wrapper
OWL
HL7 v3 Message Schema (XSD)
RDF
HL7 v3 Ontology
Normalization Map
C-Normalization Engine
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Additional Tools Used for creating HL7 v3
Message Schemas

• HL7 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

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Semantic Mediation
EDI2XML Converter
XML
HL7 v2.3 Message Schema (XSD)
HL7 v2.3 Ontology
HL7 v2.3 Message (EDI)
HL7 v2.3 Message (OWL)
Normalization Map
D-Normalization Engine
RDF
OWL Wrapper
Mapping Definition
HL7 v2.3 Message (OWL)
HL7 v3 Message (OWL)
OWL Wrapper
Normalization Map
HL7 v3 Message (OWL)
HL7 v3 Message (XML)
HL7 v3 Ontology
HL7 v3 Message Schema (XSD)
RDF
D-Normalization Engine
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Additional Tools Used for InstanceTransformation

• EDI to XML Conversion in HL7 HL7 Application
  Programming Interface (HAPI) Assembler/Disassemble
  r 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

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OWL Mapping Tool
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An Example Mapping through OWLmt
SimilarTo
Person
PID
SimilarTo
Addr
XAD
Name
PID.5.Name
PDI
Role
classCode
XON
SimilarTo
Organization
Organization_Name
Name
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An Example Mapping through OWLmt
DG1
Message
SimilarTo
DG1.4
Pulmonary Hypertension with extreme obesity
outboundRelationshipDiagnosis
DG1.3
ActDiagnosis
DataPropertyTransform
CE
actDiagnosisDescription
CE.1
Primary Pulmonary Hypertension
27679008
actDiagnosisCode
I27.2
DataPropertyTransform
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HL7 v3 Message Received by the Care2x Hospital
ltMessage xmlns"http//corttex.com/MSCorttex.xsd"gt
ltcontrolActgt ltoutboundRelationshipDia
gnosisgt ltactDiagnosisgt
ltactDiagnosisCodegtI27.2lt/actDiagnosisCodegt
ltactDiagnosisDescriptiongt Primary
Pulmonary Hypertensionlt/actDiagnosisDescript
iongt lt/actDiagnosisgt
lt/outboundRelationshipDiagnosisgt
ltoutboundRelationshipOperationgt
ltactOperationgt ltoperationCodegt9350
1lt/operationCodegt
ltoperationDescriptiongt Right Hearth
Catheterizationlt/operationDescriptiongt
lt/actOperationgt lt/outboundRelationshipO
perationgt lt/controlActgt lt/Messagegt
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Important Note

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

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Reasoning An Example
Similarity
rdfsubClassOf
SNOMED27679008-Pulmonary Hypertension with
extreme obesity
Ontology Level
instanceOf
Inferred Info
Instance Level
instanceOf
Mapping
actDiagnosisCodeI27.2
DG1-code27679008
(rdfsubClassOf cls1 cls2)(rdftype ind1 cls1)
?(rdftype ind1 cls2)
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Conclusions

• Web 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/artem
  is/
• Please come to booth 6147 to see a live demo of
  the technologies described!

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Conclusions

• Currently, 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

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Thank you very much for your attention

• Questions?