Getting sending IP/Computer from HL7 event

Question

We are currently in the design phase of a product we are building for a hospital. We want to install a custom developed software on each computer and one on a central server. It should catch the event of updated patient information of any kind when for example a patient was edited and saved in the HIS. Then on the computer on which the patient was saved we want to display information about the patient in the locally installed software.

We thought about retrieving the HL7-event from a central server and then analyze the data and send back information to our software on the sending computer. But for this we would need the IP address of the computer that caused the HL7-event (e.g. the computer on which the patient was saved in the HIS). Is there any header in which we could find the original IP address? Or when the hospital has a central HL7-server will this give us the IP address of the originally sending computer?

Or can you think of any other way to receive an information about that a patient was saved on the same computer or by the same user? E.g. listening to outgoing traffic seems to be extremely difficult and not very clean. Another option could be to detect the sending user (e.g. AD-user or LDAP-user) but is that information documented within the HL7-event in any way?

Answer 1

1. TCP level
   This is the best option I can imagine; bypassing HL7. I hope you are going to communicate on TCP level. With TCP, on receiving connection, you easily get information about clients IP address. You can use this IP for your purpose.

2. Custom field in Z segment
   Implement ZDS segment and define some field (ZDS(2) may be) with mutual communication and pass the IP address in this field.

3. Use MSH(2) (Sending Application) and MSH(3) (Sending Facility)
   Data in these fields identify the sending application and facility. If this is configured different on each computer in network, you can maintain a table in your database to map IP address against this data.