Appendix D - IPF context
The Open eHealth Framework is an endavour of the Open eHealth Foundation to ease and support the development of both messaging-oriented integration solutions and data-centric web applications in the healthcare domain. Data-centric web-applications are developed on top of the Open eHealth Application Platform whereas messaging-oriented integration solutions are developed on top of the Open eHealth Integration Platform. In context of the Open eHealth Foundation the Open eHealth Framework will be mainly used to provide open-source implementations of IHE profiles and actors. However, the Open eHealth Framework is not limited to the IHE domain and may be also used as a general-purpose framework for the development of distributed or standalone enterprise applications.
IHE
This section outlines how Open eHealth Framework applications relate to IHE profiles. Core concepts of IHE profiles are:
| Concept | IHE Definition (Technical Framework, Volume 1) | Description | Example |
|---|---|---|---|
| Actor | Actors are information systems or components of information systems that produce, manage, or act on categories of information required by operational activities in the enterprise. | An application role in a distributed system. | Patient identity cross-reference manager aka PIX manager. |
| Transaction | Transactions are interactions between actors that communicate the required information through standards-based messages. | A message exchange between actors. | Patient identitiy feed between the patient identity source and the PIX manager |
| Profile | Each integration profile is a representation of a real-world capability that is supported by a set of actors that interact through transactions. | A set of actors and transactions. | PIX profile |
The Open eHealth Framework is a development framework with special support for the implementation of IHE concepts (i.e. profiles). This is illustrated with the abstract IHE profile in Figure 1. The profile defines three actors and two transactions. Transaction 1 is between actor 1 and actor 2 whereas transaction 2 is between actor 1 and actor 3.
Figure 1: Abstract IHE profile
IHE actors are usually represented by a single application or application component i.e. the actor - component relationship is 1:1 (IHE actor - component relationships may also be 1:n or n:1). Hospital information systems often play the role of IHE actors. If you plan to develop an IHE actor from scratch the Open eHealth Application Platform is the development framework recommended by the Open eHealth Foundation.
Usually custom developed clinical information systems expose interfaces that are not aligned to IHE profiles. In order to play the role of an IHE actor in IHE transactions these interfaces must be translated to IHE-compliant interfaces. Here's where the Open eHealth Integration Platform comes into play. Integration components, developed on top of the Open eHealth Integration Platform, translate internal proprietary actor interfaces to external IHE-compliant interfaces. In addition to interface translations, integration components may also coordinate the message exchanges between other actors (e.g. using a process engine). Other integration components may also implement IHE cross-cutting concerns e.g. logging relevant message exchanges (transactions) between IHE actors to a central logging server (see IHE ATNA).
Deployment options
Figure 2 gives an overview of the most relevant deployment options of application and integration components. In this overview actor implementations always run in separate processes whereas the deployment of integration components vary:
- Embedded deplyoment: Integration components run within the same process as actor implementations
- Standalone deployment: Integration components run on a single standalone integration hub (EAI style)
- Federated deployment: Integration components run on a distributed/federeted integration platform (ESB style)
Deployment options can of course be combined for IHE profile implementations. The Open eHealth Integration Platform supports all of the above deployment options.
Figure 2: IHE Profile deployment options