Computer-Based Diagnostic Expert Systems in Rheumatology: Where Do We Stand in 2014?

Figure 2

Typical structure of a knowledge-based expert system. Based on Buchanan [3], the user interface allows the nonexpert to enter the symptoms and findings [3] and presents the diagnostic output. The knowledge base provides the knowledge. Different ways of representation, such as rules, models, or cases, can be chosen. The inference engine examines the knowledge base and produces reasoning [15]. The knowledge engineering tool allows for changing or enlarging the knowledge base by adding further rules, cases, or models [7]. There may also be an explaining component, which illustrates the diagnostic process and which gives a rationale [7]. A knowledge-based expert system with an empty knowledge base is called shell. It can be used for the development of other expert systems by adding a new knowledge base [7].