Philips Medical Systems Support for Open ECG and Standardization Efforts ED Helfenbein, R Gregg, S Zhou Advanced Algorithm Research Center Diagnostic ECG Division, Philips Medical Systems, Milpitas, CA, USA Abstract Philips Medical Systems developed a new ECG data format based on XML technology in response to increased demands for ECG data access and better ECG device interoperability. Philips has published the schema for the XML-based ECG format that is used by its electrocardiographs, bedside monitors, and defibrillators. To assist access to ECG data, Philips provides users with a set of software tools for XML-ECG waveform manipulation and display. In addition, Philips Medical Systems has been strongly supporting all national and international initiatives that are underway to standardize ECG formats and improve interoperability between diagnostic ECG devices and healthcare information systems. 1. Introduction Demands for access to electrocardiographic (ECG) data and for better interoperability among ECG devices have increased drastically in recent years. In response to such increased demands, Philips Medical Systems developed a new ECG data format based on XML (Extensible Markup Language) technology and published the schema of the data format in 2003. An XML-based ECG format is extremely well-suited for computerized interchange of information, and XML resources and tools are readily available. All Philips electrocardiographs, bedside monitors and defibrillators share and export ECGs in this XML-based format. To further assist users’ access to ECG data, Philips provides a set of software tools for XML-ECG waveform manipulation and display. This freely published set of converters can be used to transform the Philips XML ECGs into a number of formats, including Health Level 7 (HL7)/Food and Drug Administration (FDA) Annotated ECG, XML with plain text decompressed waveform values, and Scalable Vector Graphics (SVG) allowing ECG report viewing with an SVG enabled web browser. A PC-based ECG receiver program also supports electrocardiograph connectivity. On both the national and international levels, a number of efforts have been initiated to improve interoperability between diagnostic ECG devices and healthcare information systems. The HL7 Annotated ECG format adopted by the U.S. FDA for drug clinical trial ECG digital submissions has strengthened the movement towards common and publicly accessible ECG formats. The recently formed ACC (American College of Cardiology) sponsored IHE (Integrating the Healthcare Enterprise) Cardiology Technical Committee has developed a technical framework for retrieving and displaying diagnostic quality ECGs throughout the healthcare environment. Finally, the European Commission sponsored OpenECG project has initiated extensive discussions in the past two years regarding open ECG formats. As a major manufacturer of electrocardiographs, patient monitors, defibrillators and ECG management systems, Philips Medical Systems has actively participated in these efforts. 2. XML–based ECG File Format Until recently, the native format for ECG files produced by the major cardiograph manufacturers has been binary files with compression and encoding of waveform data. The compression and encoding schemes were not published, and easy access to the ECG waveform data itself by researchers and clinicians was not possible. In addition, the binary file format used to store patient demographics, measurement values, and automated interpretations forced users who wanted access to this information to write custom software based on descriptions of the binary file format. With the increased popularity and use of XML as a data interchange vehicle [1], it became clear that an XML file format for ECG storage and transmission would provide many advantages. XML is “a W3C-endorsed standard for document markup. It defines a generic syntax used to mark up data with simple, human-readable tags”[2]. XML document files are essentially tree-like structures containing labeled or “tagged” elements. Both the tags and the data elements are strings of text. Because of this, readily available text editors and web browsers can be used to 0276-6547/04 $20.00 © 2004 IEEE 393 Computers in Cardiology 2004;31:393-396.