title: The removal of wall components in Doppler ultrasound signals by using the empirical mode decomposition algorithm.
abstract: Doppler ultrasound systems, used for the noninvasive detection of the vascular diseases, normally employ a high-pass filter (HPF) to remove the large, low-frequency components from the vessel wall from the blood flow signal. Unfortunately, the filter also removes the low-frequency Doppler signals arising from slow-moving blood. In this paper, we propose to use a novel technique, called the empirical mode decomposition (EMD), to remove the wall components from the mixed signals. The EMD is firstly to decompose a signal into a finite and usually small number of individual components named intrinsic mode functions (IMFs). Then a strategy based on the ratios between two adjacent values of the wall-to-blood signal ratio (WBSR) has been developed to automatically identify and remove the relevant IMFs that contribute to the wall components. This method is applied to process the simulated and clinical Doppler ultrasound signals. Compared with the results based on the traditional high-pass filter, the new approach obtains improved performance for wall components removal from the mixed signals effectively and objectively, and provides us with more accurate low blood flow.
authors.affiliation: Department of Electronic Engineering, Information School, Yunnan University, Kunming City, Yunnan Province 650091, China. yfengzhang@yahoo.com
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yali
authors.initials: Y
authors.lastname: Gao
authors.forename: Le
authors.initials: L
authors.lastname: Wang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Chen
authors.forename: Xinling
authors.initials: X
authors.lastname: Shi
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001783:Blood Flow Velocity / Q000502:physiology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D015150:Echocardiography, Doppler / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity