The Importance of Distributed, Component-Based Healthcare Information Systems: The Role of a Service-Based Architecture David W. Forslund Los Alamos National Laboratory dwf@lan1.~o v
Internet2 mkrntz(i2i.internetZ.enti
James E. George Los Alamos National Laborator), &@ lan 1.go v
Los Alamos National Laboratory koeni&i)laul.gov .~
Robert Carter
Mary Kratz
Sascha Koenig
Torsten Staab
Duke University __
[email protected]. _ _ _ _ edir ___~
Los Alamos National Laboratory tstaah(~lanl.,oov ___ ~
INTRODUCTION The high cost of healthcare information systems (HIS) is driven by a number of factors. Proprietary systems drive the cost of interchanging data much higher than if the systems implemented standard interfaces, by not being able to leverage competitive reusable components. The HL7 data standards have been an excellent help, but provide only partial solutions, because of the normal customization that occurs at each organization. The monolithic nature of most large HIS systems make it difficult for them to be best of breed in an area and very expensive to upgrade or replace. Service-oriented, component-based technologies enable systems to be constructed of replaceable, best-of-breed components. This enables much more competition on lower-cost components, with the promise of much lower overall costs. This lower cost is driven not just by competition, but also by providing a mechanism to deal with change, by replacing software parts as newer more powerful ones become available without having to replace the entire system. The value of components is not just in their modularity, but also in the use of standard interfaces to facilitate interoperability. In addition, the ultimate value to the consumer of components is to enable the ad hoc assembly of a patient's virtual medical record over the Internet across multiple healthcare organizations'. Los Alamos National Laboratory (LANL) describes the successful implementation of standard components in an open-source system, called OpenEMed', which can be used for a variety of healthcare related applications.
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BACKGROUND The Internet has enabled much more connectivity between healthcare information systems than was possible a decade ago. However, so far, it hasn't had a major impact on the ability of organizations to interchange data4. The advent of the popularity of XML will certainly have a
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major impact on this data interchange once it thoroughly penetrates the healthcare market place. However, as implied earlier, something more than data interchange is required to really provide interoperability. There are typical operations people want to do on data, which, if standardized, will help provide the foundation for a virtual medical record. A simple example of this concept is the Domain Naming Service (DNS). It relies on a standard data format for naming computers, but also relies on a standard way of looking up a computer by name. The same applies to the popular LDAP’ service, for loolung up information about individuals. Without these fundamental services, the Internet woul’dnot be able to function, even if we could exchange data in a completely standard form. This combination of data and welldefined methods to operate on the data constitute a simple representation of an object. A set of objects with well-defined operations can constitute a scrvice. Middleware, or “glue” is the focus of an Inte1net2~initiative to define the layer of software between the network and the applications. Current services such as identification, authentication, authorization, directories and security are the center of the Internet2 Middleware activities. Today’s software applications usually have to provide these services themselves, which leads to competing and incompatible standards. By promoting standardization and interoperability, middleware will rnake advanced network applications much easier to use. The Internet2 middleware activities have spurned the formation of a Medical Middleware group. The Medical Middleware initiative is working toward the deployment of core middleware services in the medical domain for Internet2 Medical Schools and teaching hospitals. Internet2 is interested in using the Object Management Group process as a mechanism to define standard middleware components for the medical domain. Academic leadership will provide the requirements for necessary software component definitions.
DISTRIBUTED OBJECT-BASED SERVICES Standard interface requirements for medical applications are defined as service specifications by the Object Management Group Healthcare Taskforce’. These standard healthcare middleware specifications include: Person Identification Service (PIDS) provides a standardized way of managing the unique identification of individuals. Terminology Query Service (TQS) provides a standard way of looking up equivalent terms and their definitions. Clinical Observation Access Service (COAS) provides a standard way of represented a complex set of clinical observations and providing powerful retrieval methods. Resource Access Decision (RAD) service enables the implementation of a standard, access control mechanism based on information content. Clinical Image Access Service is an extension of COAS to provide robust image access mechanisms, which support the DICOM standard. These components are not intended to define the structure of a system, but rather enable a variety of systems to be developed. Standard components do not suppress innovation in an HIS, but rather encourage innovation in both implementations and in integration of these
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components. They also provide a framework for providing compliance with the new Federal HIPAA security and privacy requirements'. It is imperative that standards be based in working implementations to provide the industry with solutions, not simply paper on a shelf. Open source provides a model for standard based implementations of OMG specifications. Los Alamos National Laboratory has developed an implementation of a system using these standard middleware component definitions. OpenEMed is an open-source implementation of most of these interfaces in Java, providing extreme portability without sacrificing the ability to interoperate with a variety of different implementations of the same standards. It has been desiped to be used with a variety of database storage systems, both object-oriented and relational, with little or no recoding to move between these different persistence mechanisms. It is being deployed as the underlying infrastructure for a rapid syndrome surveillance system (RSVP)9being deployed as a pilot in the State of New Mexico and as a pilot for a New Mexico statewide immunization system.
A diagram of the system in use through the Web is shown in Figure 1. This demonstrates the flexibility of the design and how the.various components can be readily replaced or replicated without changing the overall functioning of the system.
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Figure 1: Diagram of how various components work together in the OpenEMed system utilizing standard http protocols as well as the Internet InterOrb Protocol (IIOP) between components.
Conclusion New federal regulation, such as the Health Information Portability and Accountability Act (HIPAA) will bring to bear, in the next two years, conflicting demands on the nation’s healthcare infrastructures. New regulation from the Department of Health and Human Services (HHS) will both require that healthcare providers make patient records information easily available to patients and require that they provide for the absolute security and privacy of those records. Simultaneously, developments in high-bandwidth wide-area networking will allow healthcare providers to expand their scope beyond the confines of the traditional medical campus to provide patient care in a variety of new, distributed venues. The Internet2 Medical Middleware group’s efforts are directed at designing standardized middleware infrastructures which can cope with these competing demands, providing the security, accessibility and reliability required under new HHS regulations in a more widely-distributed academic and clinical environment. As the nation’s healthcare providers strive to meet these new challenges, the combination of standardized application modules and standards-based middleware infrastructures will be critical to their success.
References
’ Health Level Seven, Inc., htt~:liwwm.hl7.ore!
* Kilman, D. G., & Forslund D.W. (1997). An International Coll;iboratory Based on Virtual Patient Records. Communicutions of the ACM. 40, I IO- I17.
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Forslund, D.W. and Kilman, D. G., The Impact ofthe Global, Ecxtensible Electronic Health Record in “Munuging Heulthcure Informution Svsrems with Web-Enubled ;rechnologies”, ed. Lauren Eder, Idea Group Publishing, 2000. Lightweight Directory Access Protocol, httr,:ii~vw.\r..innosoft.comildapworldlldanv3.httnl ht~:’lwww.intemztZ.edui http:!/licalthcare.om~.or 7 Healthcare Insurance Pckability and Accountability Act, ~ a s ~ e . h h s . e o v ! a d m n s i t n p / The Rapid Syndrome Validation Project is a joint project of Sandia National Laboratories, Los Alamos National Laboratory, New Mexico Dept. of Health, and the Univcrsity of New Mexico Hospital.
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