title: Comparison of active-set method deconvolution and matched-filtering for derivation of an ultrasound transit time spectrum.
abstract: The quality of ultrasound computed tomography imaging is primarily determined by the accuracy of ultrasound transit time measurement. A major problem in analysis is the overlap of signals making it difficult to detect the correct transit time. The current standard is to apply a matched-filtering approach to the input and output signals. This study compares the matched-filtering technique with active set deconvolution to derive a transit time spectrum from a coded excitation chirp signal and the measured output signal. The ultrasound wave travels in a direct and a reflected path to the receiver, resulting in an overlap in the recorded output signal. The matched-filtering and deconvolution techniques were applied to determine the transit times associated with the two signal paths. Both techniques were able to detect the two different transit times; while matched-filtering has a better accuracy (0.13 μs versus 0.18 μs standard deviations), deconvolution has a 3.5 times improved side-lobe to main-lobe ratio. A higher side-lobe suppression is important to further improve image fidelity. These results suggest that a future combination of both techniques would provide improved signal detection and hence improved image fidelity.
authors.affiliation: Biomedical Engineering & Medical Physics Discipline, Science & Engineering Faculty and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
authors.forename: M-L
authors.initials: ML
authors.lastname: Wille
authors.forename: M
authors.initials: M
authors.lastname: Zapf
authors.forename: N V
authors.initials: NV
authors.lastname: Ruiter
authors.forename: H
authors.initials: H
authors.lastname: Gemmeke
authors.forename: C M
authors.initials: CM
authors.lastname: Langton
mesh_terms: D003198:Computer Simulation; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D014465:Ultrasonics; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water