TIME-FREQUENCY AND TIME-SCALE ANALYSIS, DECOMPOSITION AND CLASSIFICATION OF ADVENTITIOUS PULMONARY SOUNDS
Pulmonary diseases affect the quality of life and disturb the patients throughout their life. Due to some disadvantages of auscultation with a traditional stethoscope, computerized lung sound analysis has become a necessity. In this thesis, novel non-dyadic overcomplete wavelet based methods are proposed to decompose, detect and classify primary indicators (crackle and wheeze) of pulmonary diseases using various machine learning algorithms. Crackle (explosive and discontinuous), wheeze (musical and continuous) and normal lung sounds are classified using Rational Dilation Wavelet Transform based extracted features and compared with related works. It is shown that the proposed method is more successful and faster than its competitors. Moreover, in an ensemble learning scheme it is shown that the optimal representations of signal of interest can be achieved employing the proposed method. Resonance based decomposition using Tunable Q-factor Wavelet Transform and Morphological Component Analysis techniques is proposed to decompose adventitious lung sounds and to localize crackles successfully. The proposed method is compared with related works on adventitious lung sound decomposition and is shown to perform better than other methods in terms of root mean square error, crackle localization accuracy and visual validation. Within class problem in wheeze type classification is explored using non-dyadic wavelet based features and adaptive peak energy ratio metric. It is shown that either using fixed parameter settings in wavelet transform or fixed time-frequency (TF) based features, the optimum representation and high performance can not be achieved. After repetitive experiments, it is shown that by using the proposed novel wavelet based methods, optimum and better TF and time-scale representation can be achieved.
Sezer Ulukaya received the B.Sc. degree in Electronics Engineering from Ankara University and the M.Sc. degree in Electrical and Electronics Engineering from Bahçeşehir University in 2008 and 2011, respectively. He is currently a Ph.D. candidate in the Electrical and Electronics Engineering Department at Boğaziçi University. His research interests are in pattern recognition, machine learning and signal processing with applications to facial biometrics and lung acoustics.