MYCIN was the first expert system designed for a medical application. It was developed by Dr. Edward Shortliffe in 1975 as part of his doctorate thesis. He was assisted by Ed Feigenbaum and Bruce Buchanan (who had worked on the earlier DENDRAL expert system).
MYCIN was a system for diagnosing bacterial infections in the blood, which assisted physicians to prescribe disease-specific drugs. It informed itself about particular cases by requesting information from the physician about a patient's symptoms, general condition, history, and laboratory test results. At each point, the question it asked was determined by its current hypothesis and the answers to all previous questions. Thus, the questions started as though taken from a checklist, but the questions then varied as evidence built.
The essence of MYCIN was its embedded rules of reasoning. It was made up of approximately 450 "IF-THEN" statements, such as:
IF the bacteria is a primary bacteremia
AND the suspected entry point is the gastrointestinal tract
AND the site of the culture is one of the sterile sites
THEN there is evidence that the bacteria is bacteroides
Then the succeeding questions would be directed at finding out whether bacteriode was the suspected disease agent, and what kind of bacteriode was it.
As a point of interest, MYCIN is still in use today, though not for diagnostic purposes. It is now utilised as an educational tool for medical students in the domain of bacterial infections.
The next section provides images related to the processing, rule set and user dialog of the MYCIN system. (These are thumbnail images hyperlinked to larger images.)
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This page was designed by Kersten Fernandes (Student Number: 9511727), Matthew Bird (Student Number: 9812292), and Fedja Hadzic (Student Number: 9909256),
for the COMP3330: Machine Intelligence subject within the Bachelor of Computer Science degree at the
University of Newcastle.
