ECG Classification using Wavelet Transform and
Discriminant Analysis
Farah Nur Atiqah Francis Abdullah, Fazly Salleh Abas, Rosli Besar
Faculty of Engineering and Technology
Multimedia University
Jalan Ayer Keroh Lama
75450 Melaka
Malaysia
marianne_julie@yahoo.co.uk, fazly.salleh.abas@mmu.edu.my, rosli@mmu.edu.my
Abstract—This paper focuses on two cardiac conditions, the
supraventricular ectopy and the ventricular ectopy. Four
different mother wavelets are used to produce sets of features.
Results shows that each cardiac conditions beat has its own
unique characteristics and also decomposition of different
mother wavelet produced different degree in discriminative
power. The Discriminant Analysis Classifier of different
distance metric (linear, quadratic and mahalanobis) are tested.
Classification performance mostly reached more than 90% for
both individual feature and combined feature classification.
Keywords-cardiac conditions; wavelet; discriminant analysis;
distance metric
I. INTRODUCTION
Cardiac problem has been a major health issue in these
present days considering the amount of admission caused by
the cardiac disease. Many studies have been done to assist
the prevention and early detection of the cardiac cases
among people. Thus, a lot of new algorithms have been
developed and used for that purpose. ECG beat recorded
from a person proved to be very useful in determining types
of cardiac disease that an individual is suffering from
because each and every one of the cardiac problem may
produce different patterns of ECG signal. This also proved
to be useful to distinguish which cardiac problem class does
a person’s heartbeat belongs to.
The electrocardiogram (ECG) is a signal with unique
representations of bioelectric potential with respect to time
which can be called as the heartbeat. Figure 1 shows a
typical ECG beat pattern according to [1]. Its unique
behavior can be a very useful tool for the diagnosis of
cardiac disorder. However, the classification of ECG is
quite time consuming and tedious because different patient
with the same cardiac problem may produce different shape
and regularity in its signal. Which means the conduction of
electric impulse varies from one patient to another.
Detection algorithm of the ECG signal is studied in [3]
using wavelet transform decomposition property. The R
peak of each ECG signal is very important such as it is one
of the earliest processing steps before it undergoes signal
analysis.
Various methods have been used to extract features
from the ECG signal to provide identifications of different
classes of heartbeat for signal classification. Each method
produces different degree of results depending on the
features used for the classification. The most important
features to be included in the feature selections are the RR
intervals features. Figure 1 shows the typical pattern on an
ECG signal together with its P component, QRS component
and T component annotations for clearer view. These
features are always combined with other additional features
to enhance classification performance. The classifier used
for the classification of the ECG signal also plays an
important role. Selected classifiers performances were tested
first to determine the best classifier used that is suitable for
classification using those particular features. This is because
different group of features may give out different
classification performance when tested with different type
of classifier.
Figure 1. ECG signal pattern [1]
Effective and detail study for feature extractions and
classification of ECG signal is necessary to produce the
strong and stable classifier for ECG signal classification
regardless of the condition of the signal.
2012 International Conference on Biomedical Engineering (ICoBE),27-28 February 2012,Penang
978-1-4577-1991-2/12/$26.00 ©2011 IEEE 191