The PROMIS Network

Abstract A network of minicomputers is used to support a highly interactive medical information system. The computer nodes are connected via a high-bandwidth CATV bus and conform to a polled communications discipline. Distributed across the network is a data base comprised of disjoint sets of patient medical records and a group of “network specific” files containing census information, population study data, and the like. An algorithm is employed when the network is configured to segment this data base such that the majority of accesses involve strictly intranode operation, with correspondingly rapid transaction times; the nodes thus form a loosely coupled set of processing universes communicating via “thin wire” protocols. Access to the network is granted the programmer explitly through commands such as SEND MESSAGE and COPY PARAGRAPH of a high level language developed at PROMIS and tailored to the requirements of the application. Budget constraints to date have restricted implementation to a two-node configuration which, used extensively in normal operation, has shown high reliability. Additionally, successful testing has been done with three nodes, validating the feasibility of the design.