2013-03-16

Initial Concept

Figure 1 is an over simplified block diagram for the initial concept. This may or may not be achievable, probably will change and is definitely not complete.
Figure 1

The Placer Application will be a web app or portlet. It will communicate with the backend using HL7 v2.x SIU messages. HAPI's draft standard for HL7 over HTTP will be explored as the transport.

The initial HL7 v2.x set of scheduling messages are:
  • SIU-S12 – Notification of new appointment booking
  • SIU-S15 – Notification of appointment cancellation

The Filler Channel will create or update an iCalendar document inside an IHE XDS repository. Upon successfully storing the appointment in XDS, the Filler Channel will notify VistA (playing an Auxiliary Application Role) that a new appointment was created using a HL7 SIU message.

External applications, such as email clients (Outlook, Thunderbird, etc), can request the iCalendar document using an HTTP Get request.

Finally, XACML will be used to enforce authorization.