title: Application of complex discrete wavelet transform in classification of Doppler signals using complex-valued artificial neural network.
abstract: OBJECTIVE
  In biomedical signal classification, due to the huge amount of data, to compress the biomedical waveform data is vital. This paper presents two different structures formed using feature extraction algorithms to decrease size of feature set in training and test data.
  
  
  METHODS
  The proposed structures, named as wavelet transform-complex-valued artificial neural network (WT-CVANN) and complex wavelet transform-complex-valued artificial neural network (CWT-CVANN), use real and complex discrete wavelet transform for feature extraction. The aim of using wavelet transform is to compress data and to reduce training time of network without decreasing accuracy rate. In this study, the presented structures were applied to the problem of classification in carotid arterial Doppler ultrasound signals. Carotid arterial Doppler ultrasound signals were acquired from left carotid arteries of 38 patients and 40 healthy volunteers. The patient group included 22 males and 16 females with an established diagnosis of the early phase of atherosclerosis through coronary or aortofemoropopliteal (lower extremity) angiographies (mean age, 59 years; range, 48-72 years). Healthy volunteers were young non-smokers who seem to not bear any risk of atherosclerosis, including 28 males and 12 females (mean age, 23 years; range, 19-27 years).
  
  
  CONCLUSIONS
  Sensitivity, specificity and average detection rate were calculated for comparison, after training and test phases of all structures finished. These parameters have demonstrated that training times of CVANN and real-valued artificial neural network (RVANN) were reduced using feature extraction algorithms without decreasing accuracy rate in accordance to our aim.
authors.affiliation: Selcuk University, Department of Electrical & Electronics Engineering, Engineering and Architecture Faculty, 42075 Konya, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Ceylan
authors.forename: Rahime
authors.initials: R
authors.lastname: Ceylan
authors.forename: Yüksel
authors.initials: Y
authors.lastname: Ozbay
authors.forename: Sadik
authors.initials: S
authors.lastname: Kara
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D050197:Atherosclerosis / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016571:Neural Networks, Computer; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D018608:Ultrasonography, Doppler; D055815:Young Adult