Check out our paper about implementing an HL7 version 3 modeling tool from an Ecore model
One of the main challenges of achieving interoperability using the HL7 V3 healthcare standard is the lack of clear definition and supporting tools for modeling, testing, and conformance checking. Currently, the knowledge defining the modeling is scattered around in MIF schemas, tools and specifications or simply with the domain experts. Modeling core HL7 concepts, constraints, and semantic relationships in Ecore/EMF encapsulates the domain-specific knowledge in a transparent way while unifying Java, XML, and UML in an abstract, high-level representation. Moreover, persisting and versioning the core HL7 concepts as a single Ecore context allows modelers and implementers to create, edit and validate message models against a single modeling context. The solution discussed in this paper is implemented in the new HL7 Static Model Designer as an extensible toolset integrated as a standalone Eclipse RCP application.