Integrating the Healthcare Enterprise Retrieve ECG for Display Profile Barry D. Brown, Mortara Instrument, Inc. ECG Profile co-editor IHE Cardiology Technical Committee

September 13-15, 2004IHE Interoperability Workshop 2 ECG Needs ECGs Accessible Everywhere! Need broad distribution of ECGs using ubiquitous technology (Web). – Allow medical applications to easily retrieve and display ECGs in a platform/vendor neutral way. High-quality ECG documents. Avoid artifacts on zoomed ECGs and arbitrary display geometries. – Vector images required (not rasterized) Facilitate apps for serial comparison (side-by- side synchronized display).

September 13-15, 2004IHE Interoperability Workshop 3 Goal for Year 1 High ROI—value added problem solutions Standards in place (HTTP, PDF, SVG) No “political” challenges – just technical Restricted scope for a “quick win” Reuse successful IHE IT Infrastructure Retrieve Information for Display (RID) profile to meet similar needs

September 13-15, 2004IHE Interoperability Workshop 4 In Scope for Year 1 Provide ECGs and related documents to enterprise Reuse IHE-ITI RID – Retrieve list of documents; retrieve single document – ECGs served in ready-to-display format (PDF, SVG) Limited extension for ECG-specific needs – Add requirements on display format and quality – Include XML-based ECG report list

September 13-15, 2004IHE Interoperability Workshop 5 Out of Scope for Year 1 ECG acquisition and reading workflow. ECG raw data interchange. Export of reports to external repository. Central management and configuration of ECG devices.

September 13-15, 2004IHE Interoperability Workshop 6 Year 1 Strategy Reuse IHE-ITI RID as it is: – Retrieve list of cardiology documents, including ECGs in ready-to-display format (HTML) – Retrieve single document, including an ECG – ECGs served in ready-to-display formats (PDF, SVG) – Compatibility with existing RID clients

September 13-15, 2004IHE Interoperability Workshop 7 Year 1 Strategy (cont.) Make ECG-specific extensions to RID – Place requirements on ECG source to ensure high-quality ECG documents. – Add ECG-specific request for list of ECGs to be returned as XML allowing more client flexibility. – Add SVG as allowed ECG document format.

September 13-15, 2004IHE Interoperability Workshop 8 PDF ECG Source required to support PDF so it is compatible with existing RID clients. PDF is a common document type and most computers already have a viewer. ECG Source required to use vector graphics for waveforms in PDF. – Gives high quality line drawings at any screen resolution and zoom factor. – Rasterized (e.g. scanned, bitmapped) ECG “images” not allowed.

September 13-15, 2004IHE Interoperability Workshop 9 Example ECG in PDF Format

September 13-15, 2004IHE Interoperability Workshop 10 SVG Scalable Vector Graphics – “XML Graphics for the Web” – a W3C standard. Well suited for line drawings (e.g. waveforms) in a XML/Web environment. Currently supported through web browser plug-ins. Allows scripting to enable advanced user-side display control.

September 13-15, 2004IHE Interoperability Workshop 11 Example ECG in SVG Format

September 13-15, 2004IHE Interoperability Workshop 12 Use Case D1: Simple Display Display actor requests list of ECG documents for a specific patient ID. – RID profile SUMMARY-CARDIOLOGY request returns list as HTML. – ECG profile SUMMARY-CARDIOLOGY-ECG request returns list as XML with stylesheet. Display actor requests a specific ECG document using a unique document ID. – The ID of the requested document may not have been obtained from the previously retrieved list.

September 13-15, 2004IHE Interoperability Workshop 13 Example List as HTML

September 13-15, 2004IHE Interoperability Workshop 14 Use Case D2: Advanced Display Display actor requests list of ECG documents for a specific patient ID using ECG profile request type. – List of ECGs returned as structured XML. Display actor parses structured document list to select related ECGs for serial comparison, for example. Display actor requests the specific ECG documents using the unique document IDs obtained in structured list above. Display actor displays the ECGs in a meaningful way.

September 13-15, 2004IHE Interoperability Workshop 15 ECG List XML Details IHE uses DICOM and HL7 standards, methods, and information models when appropriate. HL7 V3 has Reference Information Model (RIM) and modeling method for creating general healthcare messages. HL7 V3 method produces XML schema. XML schema for IHE ECG list developed using HL7 V3 modeling method.

September 13-15, 2004IHE Interoperability Workshop 16 ECG List HL7 V3 R-MIM

September 13-15, 2004IHE Interoperability Workshop 17 ECG List XML Schema

September 13-15, 2004IHE Interoperability Workshop 18 ECG List XML Example (1/3)

September 13-15, 2004IHE Interoperability Workshop 19 ECG List XML Example (2/3)

September 13-15, 2004IHE Interoperability Workshop 20 ECG List XML Example (3/3)

September 13-15, 2004IHE Interoperability Workshop 21 ECG List XML Example Formatted with Stylesheet

September 13-15, 2004IHE Interoperability Workshop 22 ECG List XML Example Simple Serial Comparison App.

September 13-15, 2004IHE Interoperability Workshop 23 Serial Comparison Example 23-April :45:02 23-April :47:45

September 13-15, 2004IHE Interoperability Workshop 24 For more info: IHE Cardiology Technical Framework Version 1.0 for Trial Implementation at: – – ECG List XML schema and example available at same location. Submit questions and comments to: –