title: An adaptive ultrasonic backscattered signal processing technique for instantaneous characteristic frequency detection.
abstract: Ultrasonic diagnosis that is convenient and nondestructive to the human body is widely used in medicine. In clinical, ultrasonic backscattered signals characteristics are utilized to acquire information of the human body tissues to perform diagnosis. In this paper, an adaptive ultrasonic backscattered signal processing technique for instantaneous characteristic frequency detection based on the marginal spectrum is presented. In the beginning, the ultrasonic backscattered signal is decomposed into a series of intrinsic mode functions (IMFs) by the Ensemble Empirical Mode Decomposition (EEMD) algorithm. Then the Hilbert spectrum is gained by the Hilbert transform on the IMFs decomposed and screened. Finally, the time-frequency information in the Hilbert spectrum is utilized to extract the instantaneous characteristic frequency based on the marginal spectrum features to detect the objective. With this technique, the spacing between tissues can be estimated for tissue characterization by processing multiple echoes even in the complicated environment. In the simulation study, comparing with the FFT, the technique presented shows its strong noise immunity and indicates its validity in instantaneous characteristic frequency detection.
authors.affiliation: Biomedical Engineering Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jin
authors.affiliation: Biomedical Engineering Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, China State Key Laboratory of Analog and Mixed-Signal VLSI, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, China.
authors.forename: Mang I
authors.initials: MI
authors.lastname: Vai
mesh_terms: D000465:Algorithms; D019220:High-Energy Shock Waves; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D014463:Ultrasonography / Q000379:methods*
keywords: EEMD; Hilbert spectral analysis; Ultrasonics; instantaneous characteristic frequency; simulations