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Báo cáo sinh học: " Research Article Noise and Speckle Reduction in Doppler Blood Flow Spectrograms Using an Adaptive Pulse-Coupled Neural Network"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Research Article Noise and Speckle Reduction in Doppler Blood Flow Spectrograms Using an Adaptive Pulse-Coupled Neural Network | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2010 Article ID 918015 11 pages doi 10.1155 2010 918015 Research Article Noise and Speckle Reduction in Doppler Blood Flow Spectrograms Using an Adaptive Pulse-Coupled Neural Network Haiyan Li Yufeng Zhang and Dan Xu School of Information Science and Engineering Yunnan University Kunming Yunnan 650091 China Correspondence should be addressed to Haiyan Li lLcannie@hotmail.com Received 1 January 2010 Accepted 14 May 2010 Academic Editor Lutfiye Durak Copyright 2010 Haiyan Li et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. A novel method called adaptive pulse coupled neural network AD-PCNN using a two-stage denoising strategy is proposed to reduce noise and speckle in the spectrograms of Doppler blood flow signals. AD-PCNN contains an adaptive thresholding PCNN and a threshold decaying PCNN. Firstly PCNN pulses based on the adaptive threshold filter a part of background noise in the spectrogram while isolating the remained noise and speckles. Subsequently the speckles and noise of the denoised spectrogram are detected by the pulses generated through the threshold decaying PCNN and then are iteratively removed by the intensity variation to speckle or noise neurons. The relative root mean square RRMS error of the maximum frequency extracted from the AD-PCNN spectrogram of the simulated Doppler blood flow signals is decreased 25.2 on average compared to that extracted from the MPWD matching pursuit with Wigner Distribution spectrogram and the RRMS error of the AD-PCNN spectrogram is decreased 10.8 on average compared to MPWD spectrogram. Experimental results of synthetic and clinical signals show that the proposed method is better than the MPWD in improving the accuracy of the spectrograms and their maximum frequency .