Health level seven: the cornerstone of medical informatics tutorial presentation
Authors: George Whitson
Venue: Journal of Computing Sciences in Colleges (2009)

Medical informatics is the intersection of computer science, information systems and the medical system. The cost of medical care has increased greatly over the past twenty years and many have expressed an interest in using medical informatics as a way to reduce this cost. Originally, Health Level Seven (HL7) was introduced as an OSI application layer network protocol to support the interchange of medical information among a wide variety of medical applications and devices. This culminated in the approval of version 2.5 of HL7 in 2003 by the Health Level Seven Organization. HL7 version 2.5 was a robust network protocol that has been implemented by many organizations. While HL7 version 2.5 supported the exchange of information between applications and devices reasonably well when implemented by a single vendor, it suffered from the same problems as many of the OSI layer seven protocols (FTP, for example) in that applications from different vendors could not communicate. In 2000, the HL7 Organization began work on version 3 of HL7. HL7 version 3 had the same goal as the earlier versions of HL7, that is to support universal communications among medical applications and devices, but it plans to do this using the full power UML to specify the entire medical process. Once this has been accomplished, HL7 version 3 provides a process for many Implementation Technology Specifications (ITSs) to actually represent medical data and the exchange of messages. The first ITS will be to represent all medical data and messages in XML. The work on implementing HL7 as the backbone of medical informatics, and creating an electronic health record, is moving forward at a rapid pace. One example is the work of Microsoft's work with the Kaiser Permanente Health Organization, its integration of Office and BizTalk Server to support HL7 and its Connected Health Framework (CHF) as an architecture to tie everything together. HL7 is a massive application of computer and information science to medical informatics, but it is just beginning to be taught in courses. This tutorial will give an overview of medical informatics and HL7 that will make entry into this field easier. It will also provide some examples of how this important topic can be introduced into computer science and information science curriculums. Topics covered in the tutorial will include: &bull; A HL7 View of Medical Informatics &bull; Some basic definitions in medical informatics &bull; The Electronic Health Record (HER) of an individual &bull; A UML view of medical informatics &bull; The Reference Information Model (RIM) &bull; The key RIM pattern &bull; The main RIM classes &bull; A Historical Introduction to HL7 &bull; The beginnings of HL7 &bull; Version 2.5 &bull; The structure of a message &bull; Message protocols &bull; Version 3 &bull; The RIM and Domains &bull; Medical scenarios &bull; Vocabularies and Data Types &bull; Messages and Hierarchical Message Descriptions &bull; Clinical Document Architecture (CDA) &bull; A HL7 Version 3 Example &bull; A doctor orders a blood test &bull; The doctor and the test &bull; The order &bull; Some Interesting HL7 Areas &bull; HL7, security and privacy &bull; Implementing HL7 using Web Services &bull; Some Examples of Using HL7 in Teaching &bull; HL7 in Capstone Courses &bull; HL7 in Web Design courses &bull; An Enterprise Systems Course Emphasizing Medical Systems