FUZZY L sets and systems ELSEVIER Fuzzy Sets and Systems 77 (1996) 63 75 Fuzzy modelling of the expert's knowledge in ECG-based ischaemia detection J. Presedo a'*, J. Vila a, S. Barro a, F. Palacios b, R. Ruiz c, A. Taddei d, M. Emdin d =Dpto. Eleetr6niea y Computaei6n, University of Santiago de Compostela, 15706 Santia9o de Compostela, Spain b General Hospital ofElehe, Elche, Spain c University of Mureia, Cartagena, Spain d CNR Institute of Clinical Physiology, Pisa, Italy Abstract We concentrate on computational implementations of the detection ofischaemic episodes in order to allow continuous monitoring of patients interned in Coronary Care Units (CCU). The consideration of several alternatives led us to choosing an implementation based on the expert's knowledge as the most adequate. In order to solve the problem of transforming the imprecise knowledge provided by the expert into computable structures we have decided to make use of a fuzzy implementation. We illustrate and comment the operation of our solution over some records of the European ST-T Database, which is an electrocardiographic database specifically aimed at the validation of algorithms whose objective is the detection of ischaemic episodes. This work can be included in the more general problem of the design, physical implementation and validation of an electronic-computational system (SUTIL), which by means of the simultaneous, integrated and intelligent evaluation of a large amount of information extracted from real time processing of haemodynamic and electrocardiographic signals, performs an intensive and exhaustive follow up of patients with ischaemic cardiopathies interned in CCUs. Keywords: Approximate reasoning; Artificial intelligence; Expert systems; Medicine; Ischaemia detection; Patient monitoring 1. Introduction evolves towards a situation of permanent irrevers- Acute myocardial infarct (AMI), or ischaemic ible lesion, going through an ischaemic phase in necrosis of the left ventricle is the final result of the which the muscular mass of the heart affected can irreversible stoppage of the nutritious blood flow still be recovered as viable tissue. In a simple way, and the provision of oxygen to the heart muscle, we can consider as an ischaemic episode the process When an infarct occurs, the myocardial muscle between the stoppage of blood flow to a part of the miocardia and the return to normality of the tissue. Given the type of pathologies patients interned in Intensive Care Coronary Units (ICCUs) present, *Corresponding author. Email: elsuso@usc.es, ischaemic episodes are relatively frequent. Their 0165-0114/96/$09.50 © 1996 - Elsevier Science B.V. All rights reserved SSDI 0165-0114(95)00124-7