need urgent answers HL7 interface( need in 3 or 4 hours )

The system should work as follows: 1. Clinician sees a patient at the health center, decides that they need to see a specialist and creates a referral order in the health center EHR. 2. Specialist visit request appears in the e-referral portal where a referral coordinator contacts the patient and then manually schedules the visit in the hospital scheduling system. 3. Patient is examined by specialist, the specialist documents the findings from the visit in the hospital EHR. 4. After the specialist visit the results of the specialist visit appear in the health center EHR and the visit request is marked as completed in the e-referral portal. The following conditions exist: 1. There is network connectivity between all involved entities. 2. There will be no interface between the e-referral portal and the hospital scheduling system this is a manual process. 3. The hospital has a modern interface engine and all HL7 messages flow through that both inbound and outbound. 4. The health center does not have an interface engine but their EHR is set up to send and receive HL7 v2.x messages for orders and results. 5. The only messages you need to be concerned with are orders and the results of the specialist examination (it will be a visit note) Answer the following: 1. List all HL7 interfaces you feel will be required for this overall system including the source system, destination system, and what data is being sent (order or result). 2. Will the order messages be pushed from the health center to the hospital or pulled by the hospital? Why? 3. If the hospital EHR system produces results messages using a CCD format, what challenges will that pose to the overall system?