The development of a client/server architecture for standardized medical application network services

Recently, there has been a great demand for distributed medical imaging systems to share information among medical institutions in an interoperable fashion. Connectivity between medical institutions requires sharing complete protocols defined by standards. The "DICOM" standard is evolving to define the communication messages and application services between two medical applications. We specify and design the client and server behaviour of the Upper Layer service of the DICOM standard using an object oriented pattern language. The hierarchy principle of statechart is used to facilitate the comprehensibility of the standard by providing a visual formalism for the specification. The specification distinguishes the behaviour of the Upper Layer services as a client or a server. A high level structure of the client/server is illustrated using a collaboration diagram for an association establishment scenario. Finally, a statechart object oriented pattern language is used to translate the specification into design, and a class diagram for the server is presented in UML notation.