Loading...

Multiple wavelet denoising for embolic signal enhancement

Marvasti, S ; Sharif University of Technology | 2007

582 Viewed
  1. Type of Document: Article
  2. DOI: 10.1109/ICTMICC.2007.4448575
  3. Publisher: 2007
  4. Abstract:
  5. Transcranial Doppler ultrasound can be used to detect circulating cerebral eraboli. Embolie signals have characteristic transient chirps suitable for wavelet analysis. We have implemented and evaluated the first online selective selective wavelet transient enhancement filter to amplify embolic signals in a preprocessing system. Our approach is similar to wavelet de-noising for signal enhancement, but, in order to retain blood flow information, we do not use traditional threshold methods. The selective wavelet amplifier uses the matched filter properties of wavelets to enhance embolic signals significantly and improve classification performance using a novel noise tolerant approach. Even the smallest embolic signals are enhanced. We show an increase of over 2dB (on average) in embolie signal strength and a significant improvement in detection accuracy when our filter is applied both to a commercially available detection system and an in house frequency based detection system. The implementation of the filter is simplified by using an optimized matrix form. The block matrix form is significantly faster than the normal recursive discrete wavelet transform implementation6. ©2007 IEEE
  6. Keywords:
  7. Adaptive filtering ; Automatic detection ; Block matrices ; Blood flows ; Cerebral embolism ; Classification performance ; Denoising ; Detection accuracy ; Detection systems ; Embolic signals ; International conferences ; Malaysia ; Matched filtering ; Noise-Tolerant ; Signal enhancement ; Signal strengths ; Threshold methods ; Transcranial Doppler ultrasound ; Wavelet de-noising ; Wavelets ; Discrete wavelet transforms ; Electric fault currents ; Hemodynamics ; Imaging techniques ; Matrix algebra ; Medical imaging ; Sensors ; Signal detection ; Telecommunication systems ; Wave filters ; Wavelet transforms ; Ultrasonic applications
  8. Source: 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 658-664 ; 1424410940 (ISBN); 9781424410941 (ISBN)
  9. URL: https://ieeexplore.ieee.org/document/4448575