Indonesian Journal of Electrical Engineering and Computer Science
Vol. 12, No. 3, December 2018, pp. 984~994
ISSN: 2502-4752, DOI: 10.11591/ijeecs.v12.i3.pp984-994 984
Journal homepage: http://iaescore.com/journals/index.php/ijeecs
Comparison of Multiscale Entropy Techniques for Lung Sound
Classification
Achmad Rizal
1
, Risanuri Hidayat
2
, Hanung Adi Nugroho
3
1,2,3
Department of Electrical Engineering & Information Technology,
Universitas Gadjah Mada, Jl Grafika no 2, Mlati, Sleman, D.I. Yogyakarta, Indonesia
1
School of Electrical Engineering, Telkom University
Jl Telekomunikasi no 1, Ters. Buah Batu, Bojong Soang, Bandung, Indonesia
Article Info ABSTRACT
Article history:
Received Apr 27, 2018
Revised Aug 24, 2018
Accepted Oct 8, 2018
Lung sound is a biological signal that can be used to determine the health
level of the respiratory tract. Various digital signal processing techniques
have been developed for automatic classification of lung sounds. Entropy is
one of the parameters used to measure the biomedical signal complexity.
Multiscale entropy is introduced to measure the entropy of a signal at a
particular scale range. Over time, various multiscale entropy techniques have
been proposed to measure the complexity of biological signals and other
physical signals. In this paper, some multiscale entropy techniques for lung
sound classification are compared. The result of the comparison indicates
that the Multiscale Permutation Entropy (MPE) produces the highest
accuracy of 97.98% for five lung sound datasets. The result was achieved for
the scale 1-10 producing ten features for each lung sound data. This result is
better than other seven entropies. Multiscale entropy analysis can improve
the accuracy of lung sound classification without requiring any features other
than entropy.
Keywords:
Multiscale entropy
Lung sound
Coarse-grained procedure
Multilayer perceptron
Copyright © 2018 Institute of Advanced Engineering and Science.
All rights reserved.
Corresponding Author:
Achmad Rizal,
Department of Electrical Engineering & Information Technology,
Universitas Gadjah Mada,
Jl Grafika no 2, Mlati, Sleman, D.I. Yogyakarta, Indonesia.
Email: rizal.s3te14@mail.ugm.ac.id
1. INTRODUCTION
Lung sound is one of the biological signals that emerge from the respiration process. Any changes in
it are generated from foreign bodies or physiological changes in the respiratory tract caused by diseases [1].
Differences in patterns of lung sounds can be heard by a doctor using a stethoscope to diagnose diseases [2].
Auscultation technique, on the other hand, is very subjective for being dependent upon existing experience
and expertise of the doctor.
Various techniques for analyzing lung sounds using computers have been developed. Some of these
techniques include time-domain analysis techniques, such as statistical analysis based on Hjorth
descriptor [3], empirical mode decomposition (EMD) [4], or fractal analysis [5]. Several researchers
proposed to perform lung sound analysis in the frequency domain, such as quantile vector frequency [6] or
MFCC [7]. Meanwhile, wavelet analysis has been used in [8] for classifying abnormal lung sounds.
One of the popular biological signal analysis methods is multiscale entropy (MSE), proposed by
Costa et al. with a coarse-grained procedure for multiscale process and sample entropy for entropy
measurement [9]. Subsequently, several variants of MSE emerge such as refined-MSE, composite-MSE or
adaptive MSE (AME) [10]. Other researchers modified their entropy measurement techniques, which result
in multiscale permutation entropy (MPE) [11], multiscale approximate entropy (MApEN) [12], and
multiscale fuzzy entropy [13]. In the case of lung sounds, multiscale entropy has been used to analyze the