Summary
Objectives:
Fuzzy rules automatically derived from a set of training examples quite often produce
better classification results than fuzzy rules translated from medical knowledge.
This study aims to investigate the difference in domain representation between a knowledge-based
and a data-driven fuzzy system applied to an electrocardiography classification problem.
Methods:
For a three-class electrocardiographic arrhythmia classification task a set of fifteen
fuzzy rules is derived from medical expertise on the basis of twelve electrocardiographic
measures. A second set of fuzzy rules is automatically constructed on thirty-nine
MIT-BIH database’s records. The performances of the two classifiers on thirteen different
records are comparable and up to a certain extent complementary. The two fuzzy models
are then analyzed, by using the concept of information gain to estimate the impact
of each ECG measure on each fuzzy decision process.
Results:
Both systems rely on the beat prematurity degree and the QRS complex width and neglect
the P wave existence and the ST segment features. The PR interval is not well characterized
across the fuzzy medical rules while it plays an important role in the data-driven
fuzzy system. The T wave area shows a higher information gain in the knowledge based
decision process, and is not very much exploited by the data-driven system.
Conclusions:
The main difference between a human designed and a data driven ECG arrhythmia classifier
is found about the PR interval and the T wave.
Keywords
Arrhythmia - Fuzzy Logic - Artificial Intelligence
