Evaluation of Strategies for Generalised Cases within a
Case-Based Reasoning Antibiotics Therapy
Advice System

Rainer Schmidt and Lothar Gieri

Institut fr Medizinische Informatik und Biometrie, Universitt Rostock
Rembrandtstr. 16 /17, D-18055 Rostock, Germany
{rainer.schmidt, lothar.gieri}@medizin.uni-rostock.de


Abstract. For an intensive care unit, we have developed an antibiotics
therapy advice system, called ICONS. To speed-up the process of
finding suitable therapy recommendations we have applied Case-based
Reasoning techniques. As in a medical expert system all required
information should always be up-to-date, a static case base is
inappropriate. New cases should be incrementally incorporated into the
case base and outdated ones should be updated or erased. For reasons of
space limitations and of retrieval time an indefinite growth of the case
base should be avoided. To fulfil these requirements we propose to
generalise from single cases to prototypical cases and to erase redundant
cases. In this paper, we mainly focus on results of extended experiments
with generation strategies of generalised cases (prototypes).
Additionally, we compare measured retrieval times for two indexing
retrieval algorithms: For simple indexing and Tree-Hash retrieval.
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