Here is a cute, little interface project that I knocked out in a couple of days.
One of our business partners is sending us what they call "patient list" data. This is information on patient groupings. For example, a patient could be on the "Gastroenterology Consults" list. This is information that does not come across in the organizations ADT stream, and the likelihood of getting it added to that was pretty low. Instead, they send us a patient list file which would contain a record for each patient and the patient list that they are on. They generate this as a Comma Separated Value (CSV) file and would send that to us as a flat file. I built a route and a mapping in the engine to take the flat file, generate an HL7 A08 (patient udate) message for each patient and place the Patient List information into the PV2-23 field (ClinicOrganizationName). The route then places each ADT message into the ADT stream for the appropriate system.
The A08 updates the basic patient demographic information by only adding the patient list information to the PV2-23 field ClinicOrganizationName. They can then select all patients that are currently in the Neurology list, for example. The receiving system gets the Patient List information with no changes required.
We already had a mechanism in place to exchange flat files, so they added this file to the stream. On the receiving end I have a script that looks at each file, identifies which one it is and routes it for processing. I added the new file to the script and built a new route to process the patient list file.
I then had to build a data structure for the CSV, which was pretty straightforward. I then built a special ADT structure that contained multiple A08 messages, and then a Map (that is the Rhapsody term, in Cloverleaf, this would be a Translate) to map the data from the CSV file to the ADT Message. After this, I added a DeBatch filter to the route to split each of the A08s into a separate message.
I had not built this sort of interface before, so I learned a little bit doing it. The trickiest part was getting the file structure definitions set up correctly. The actual mapping took about an hour to build and test.