HL7 Overview Gliwice January 10 th, 2009

 What is HL7?  HL7 in Healthcare Management Systems  Message structure  Message encoding schemes  HL7 tools Agenda

Protocol for data exchange between computer systems in health care environments. Defines messages as they are exchanged and the procedures used for exchanging them. Refers to the top layer (Level 7) of OSI/ISO layer model (see next slide). ANSI standard since 1997 most widely used in USA, Canada, Australia, New Zealand and Japan. What is HL7 (Health Level Seven)?

Application Type of network communication ( , telnet, FTP, HL7) Data conversion, encryption Presentation Session Controlling dialogues (sessions). Establishing, terminating and restarting connection. Transport Network Data-Link Physical Network adapter: Ethernet, wireless Ethernet Physical link: Ethernet cable, RS-232, optical link TCP/IP Routing, reliable data transport between two computers

What is HL7 (Health Level Seven)? HL7 contains message standards covering: Patient Administration Orders for Clinical Services and Observations, Pharmacy, Nutrition and Supplies order entry Patient Accounting and Charges Observation Reporting Document Management Services Appointment Scheduling Laboratory Automation Personnel Management …

 What is HL7?  HL7 in Healthcare Management Systems  Message structure  Message encoding schemes  HL7 tools Agenda

HL7 in Healthcare Management System

 What is HL7?  HL7 in Healthcare Management Systems  Message structure  Message encoding schemes  HL7 tools Agenda

Message structure HL7 messages are made up of segments Segments are units that comprise messages. A segment is defined as a sequence of fields. Both segments and fields may appear more than once in a message. Examples of HL7 message segments: MSH - Message Header information about a message EVN - Event Type event information PID - Patient Identification information about a patient NK1 - Next of Kin information about the patient's other related parties OBR - Observation Request information about an order OBX - Observation Report information about a result

Message structure HL7 Message Example

Message structure Types of messages Most applicable HL7 messages for communicating HIS and diagnostic systems: ACK – General Acknowledgment message ORM – General Order message ORR – General Order Response message ORU – Unsolicited Transmission of Observation

Message structure Data Exchange No data exchange, messaging and communication technologies are determined by HL7. Frequently used protocols in HL7 implementations: LLP (Lower Layer Protocol) – TCP/IP based SOAP (Simple Object Access Protocol) – XML based Batch Files – messages in text files exchanged by FTP and SMTP or offline via a tape or a diskette

 What is HL7?  HL7 in Healthcare Management Systems  Message structure  Message encoding schemes  HL7 tools Agenda

Message encoding schemes HL7 uses two encoding schemes: HL7 ER, also known as 'traditional' HL7 format; used for HL7 versions 2.x XML primary encoding scheme for HL7 v 3.0 can be used for HL7 v 2.x in environments where sender and receiver both understand XML

Message encoding schemes HL7 ER Sample message encoded in HL7 ER format

Message encoding schemes XML Sample message encoded using XML scheme | ^~\& LAB foo bar ADT

Message encoding schemes HL7 is not Plug & Play Some vendors do not follow HL7 rules close enough. The same data could be placed in different segments of different HL7 implementations. Not all data types may be coded using standard HL7 format. For these types vendor specific messages and fields must be used. When deploying system utilizing HL7 interface, it still must be adapted to hospital-specific requirements.

 What is HL7?  HL7 in Healthcare Management Systems  Message structure  Message encoding schemes  HL7 tools Agenda

HL7 tools There are many HL7 tools assisting developers in the following areas: Parsing and converting messages. Validating messages in accordance with HL7 standard and user-defined rules. Simulating HL7 message sender (e.g. HIS) for diagnostic purposes. Networking features required for HL7: TCP/IP sockets, FTP, SOAP, other.

HL7 tools Chameleon, Iguana, Interfaceware ProtoGen/HL7 BizTalk Server and BizTalk Accelerator for HL7 default.mspx default.mspx

Many thanks for your attention! Iwona Machowska Marketing & New Business Manager Ul. Toszecka Gliwice, Poland Tel