The HELIOS project

The Division of Medical Informatics was one of the members of the HELIOS project, and the aim was to provide methods and tools for development and realization of data driven decision support that can be integrated into ward information systems. The DSS components (see figure below) include tools for knowledge acquisition and knowledge base construction, provide trigger mechanisms for evokation of the knowledge base, and an inference engine, controlling the execution. The work is based on the Arden Syntax, a standard for knowledge representation which allows medical logic modules (MLMs) to be shared and transferred between institutions. During the DSS building process, the knowledge modules are pre-compiled to the object-oriented programming language C++. The pre-compiler also produces an evoke table to be used during run-time, and a trigger table to be used by the database manager. The DSS contains a library of knowledge modules and a run-time controller or MLM engine (also implemented as a C++ program) which contains an inference engine with an event handler, a library with all operators of the Arden Syntax (LASO), and a communication interface, sending and receiving messages over the HELIOS Unification Bus. If appropriate triggers are set up in the patient database according to the evoke definitions, the DSS will be able to execute parts of its knowledge base according to actions in the patient database, that is a data driven DSS is realized.