Bulletin Spring‧Summer 1997

highlights of RGC-funded Projects A World of Imprecision Precise and definite information about real world objects is difficult to obtain, and, in the realm of medicine, such information is not always accessible to doctors for diagnosis and treatment. This is not so surprising as the relationship between symptom and disease is sometimes vague, and the state of a patient can be very hard to define. The explosion of medical knowledge further complicates the problem. Doctors are faced with a large amount of fuzzy and uncertain information, from which medical conclusions have to be derived and on which therapeutic actions have to be based. Who can they turn to for help? Prof. K. S. Leung of the Department of Computer Science and Engineering has come up with a fuzzy expert shell called Z-III With this development tool he and other researchers at the University have built several medical expert systems that can be applied to obstetrics and gynaecological cases. The project, entitled 'An Expert Computer System on Medical Consultation and Management', was financed by an earmarked grant of HK$310,000 from the Research Grants Council in 1989. A FuzzyExpertShell— Z - I I I Z-III is a structured and modular rule- based shell (see figure A) that is menu-driven and easy to learn. It incorporates both fuzzy logic as propounded by L.A. Zadeh and the certainty factor model used in MYCIN — a medical expert system. Fuzzy concepts such as 'very dry' or 'rather heavy' are represented Figure A : The Structure of Z-III Medical Decisions Based on Fuzziness and Uncertainty 37