CCTOS:  Software Architecture

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Draft Version 6.5, 10 May 2011, Etienne Saliez, ---- Next - Previous - Index of CCTOS Issues,  

• Issues:
  • The main objective of the project is patient care.  A patient may need care from a very large panel of specialized services, requiring an integration platform.
  • To make distributed developments possible.
    
  • The logic of the intended medical applications require a relatively large set of temporary persistent information. More information than just a few data about the next HTML page to be displayed, as usual in many web frameworks.
  • The general philosophy should be real time and measures should be foreseen in order to prevent conflicts in case that 2 users would be working on the same record.
    
• Approaches:
  • A very modular approach:
    • A "Core" intended as a generic integration platform.
    • As far as possible reuse of software components available in Open Source and adapted as "services".  Interfaces allowing that these external component may be in different programming languages.
  • The Core itself is also a component to be upgraded step by step, although particularly critical.  The Core of the experimental prototype is in Python.  A choice in function of a good level of abstraction, a great flexibility, availability of large libraries and a growing and a mostly open source minded community.
    
  • Incremental development beginning by relatively simple components, to be upgraded one at a time.
    
  • A compromise between a traditional application logic and a stateless web framework.  This can be seen as 2 levels:
    • Core Patient Record Coordination Logic.  A multi-user setup, but during a user session, maintenance of a Session object containing temporary session data related to the current user.  Every user should have such a session object.  Session objects should be maintained on a fast type of memory.
    • Front-end web interface dealing with all the external communications, in principle called "views".  The most frequent views are intended for a web browser, but other types of "views" should also foreseen in the front-end, as smart phones, HL7 messages exchanges, etc...
  • .... more information at http://www.chos-wg.eu/Tech/VCT-Network-Architecture.html .