The purpose of this report is to examine different transport mechanisms
and to evaluate their effectiveness in performing health care
related tasks. We selected five different transport mechanisms
to examine: CORBA (Common Object Request Broker), OLE (Object
Linking and Embedding), PII (Portable Independent Interfaces,
specifically sockets), SQL/RDA (Remote Database Access) and RPC
(Remote Procedure Call). Each of these were evaluated using five
criteria:
A demonstration project was created in conjunction with this report. The goal of the demonstration project was to give an example of how the various communication technologies can be used in an actual application. We built two viewers of patient record data. One viewer was a POSIX (Portable Operating System Interface for Computer Environments, see [IEEE1003.1c] and others) client that used a Hyper Text Markup Language (HTML) browser to examine patient data. The HTML browser found its data through a CORBA interface. The CORBA interface determined where the data of interest was located and queried the remote database using SQL/RDA.
The second viewer used OLE. Since OLE is not yet a distributed mechanism, this viewer had a different function. The viewer was used to contain patient data that has already been collected from other sites into a patient report. Additional documents created by other applications could also be added to the patient report. For example, an article concerning new treatment taken from a medical journal could be incorporated. The viewer also had limited database querying ability. Local databases which support the ODBC (Open Database Connectivity) protocol could be queried. This viewer was more limited than the previous viewer in the sense that it had to know the exact host on which the data resided.
In this section of the report we have presented a general project overview. The next section will review each of the distributed communication methods and apply the evaluation criteria to each. After that is the section presenting a technical overview of role-based access control. The following section covers the demonstration project. Finally, we will present our conclusions.