Directional Dual-Tree Rational-Dilation Complex Wavelet Transform

Serbes G. , Gulcur H. O. , AYDIN N.

36th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society (EMBC), Illinois, United States Of America, 26 - 30 August 2014, pp.1465-1468 identifier identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1109/embc.2014.6943877
  • City: Illinois
  • Country: United States Of America
  • Page Numbers: pp.1465-1468


Dyadic discrete wavelet transform (DWT) has been used successfully in processing signals having nonoscillatory transient behaviour. However, due to the low Qfactor property of their wavelet atoms, the dyadic DWT is less effective in processing oscillatory signals such as embolic signals (ESs). ESs are extracted from quadrature Doppler signals, which are the output of Doppler ultrasound systems. In order to process ESs, firstly, a pre-processing operation known as phase filtering for obtaining directional signals from quadrature Doppler signals must be employed. Only then, wavelet based methods can be applied to these directional signals for further analysis. In this study, a directional dual-tree rational-dilation complex wavelet transform, which can be applied directly to quadrature signals and has the ability of extracting directional information during analysis, is introduced.