Healthcare is an increasingly collaborative enterprise involving many individuals and organizations that coordinate their efforts toward promoting quality and efficient delivery of healthcare through the use of interoperable healthcare information systems (HIS). Service-oriented architecture (SOA) provides a cost-effective solution to implementing interoperability between heterogeneous HIS which have resulted from extensive investments that most healthcare organizations have made in system resources over the course of many years. However, issues of semantic interoperability still remain unresolved while new challenges arise regarding web service interoperability. This chapter presents a mediator-based approach for achieving data and service interoperability among disparate and geographically dispersed HIS. The proposed system architecture provides a uniform interface to the underlying HIS, thus enabling decoupling of the client applications and the server-side implementations while it ensures security in all transactions. It is a distributed system architecture based on the agent paradigm for both healthcare process management and management of interactions among the participating systems. The healthcare processes and all interactions involved in each process are described according to the workflow metaphor. Thus, robustness, high flexibility and fault tolerance are provided in an environment as dynamic and heterogeneous as healthcare.
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Healthcare delivery involves a broad range of in-patient, out-patient and emergency healthcare services, typically performed by a number of geographically distributed and organizationally disparate healthcare providers who often invest significant resources in the development of large and complex information systems. Technologically innovative efforts of the past have often resulted in the development of disparate, incompatible and heterogeneous systems based on the traditional transaction processing paradigm rather than on supporting business processes. However, healthcare providers’ activities require increased collaboration and coordination in order to provide shared and integrated care when and where needed (Malamateniou and Vassilacopoulos, 2003). Thus, the integration of diverse and disparate information systems with emphasis on communication and collaboration is a challenge often faced by healthcare organizations (Lenz and Kuhn, 2004; Huizen and Backman, 2005). This challenge can be met by means of interoperable healthcare information systems (HIS) that support a process view of the healthcare delivery context and also facilitate communication among diverse systems on an ongoing basis, despite different purposes, structures, and underlying technologies. Such systems may assist in realizing collaboration among healthcare providers and in providing readily access to patients’ longitudinal health records by authorized users at the point of care. This, in turn, will improve the quality, efficiency, and effectiveness of healthcare delivery – dimensions of healthcare in need of innovation and improvement.
When an interoperable HIS is envisaged, communication-level interoperability issues need to be solved in order to ensure that existing systems using different transport protocols and data formats can exchange information. Such interoperable HIS can be realized according to the Service-Oriented Architecture (SOA) which can solve these issues to a great extent while protecting past investments since existing information assets and applications are preserved (Wang and Wang, 2005). However, data integration issues are not fully addressed while new challenges are created regarding interoperability due to inconsistencies in web service implementations (Cohen, 2002). Thus, the movement towards such an interoperable HIS requires an architecture that implements interoperability among existing information systems in all levels, including service and data levels. The effective management of interactions in such a heterogeneous and distributed environment is a fairly complex task. The conjunction of agent and workflow technologies provides the ability to execute such complex tasks and helps managing the complexity of the distribution in terms of both administration and fault tolerance. In particular, these technologies can be used for the integration of existing systems both within and across different healthcare organizations by integrating the common data and business logic into a specific architectural layer (i.e. middleware) distinct from individual applications and accessible through the whole HIS.
This chapter presents a, compatible to the EN 12967 standard (ISO/TC 215, 2008), mediator-based system architecture that addresses HIS interoperability issues while it complies with the most stringent requirements of high performance, reliability, robustness, scalability, high flexibility and fault tolerance. The proposed system architecture utilizes both workflow and agent technologies for supporting healthcare process collaboration and coordination requirements and for resolving data integration issues. In particular, it uses a set of cooperating agents for managing healthcare processes and handling all the interactions between the client applications and the existing HIS initiated during healthcare process enactment. Moreover, java-based workflows are used for modeling both the healthcare processes and the logics of all interactions as well as the internal behavior of system participating in these interactions. The latter are workflows that may involve several tasks such as data retrieval and transformation, computations and other low level auxiliary operations needed during execution of a process handling a client request.