Abstract : In ultrasound harmonic imaging with chirp-coded excitation a harmonic matched filter (HMF) is typic
more
Abstract : In ultrasound harmonic imaging with chirp-coded excitation a harmonic matched filter (HMF) is typically used on the received signal to perform pulse compression of the second harmonic component (SHC) to recover signal axial resolution. Designing the HMF for the compression of the SHC is a problematic issue because it requires optimal window selection. In the compressed second harmonic signal the sidelobe level may increase and the mainlobe width (MLW) widen under a mismatched condition resulting in loss of axial resolution. We propose the use of the fractional Fourier transform (FrFT) as an alternative tool to perform compression of the chirp-coded SHC generated as a result of the nonlinear propagation of an ultrasound signal. Two methods are used to experimentally assess the performance benefits of the FrFT technique over the HMF techniques. The first method uses chirp excitation with central frequency of 2.25 MHz and bandwidth of 1 MHz. The second method uses chirp excitation with pulse inversion to increase the bandwidth to 2 MHz. In this study experiments were performed in a water tank with a single-element transducer mounted coaxially with a hydrophone in a pitch-catch configuration. Results are presented that indicate that the FrFT can perform pulse compression of the second harmonic chirp component with a 14 reduction in the MLW of the compressed signal when compared with the HMF. Also the FrFT provides at least 23 reduction in the MLW of the compressed signal when compared with the harmonic mismatched filter (HMMF). The FrFT maintains comparable peak and integrated sidelobe levels when compared with the HMF and HMMF techniques.Copyright 2010 World Federation for Ultrasound in Medicine amp Biology. Published by Elsevier Inc. All rights reserved.PMID 20510187 PubMed - indexed for MEDLINEMeSH TermsMeSH TermsData CompressionFourier Analysis*Signal Processing Computer-Assisted*Ultrasonics*LinkOut - more resourcesFull Text SourcesElsevier ScienceEBSCOOhioLINK Electronic Journal CenterSwets Information ServicesOther Literature SourcesCOS Scholar Universe Supplemental Content Related citations Harmonic chirp imaging method for ultrasound contrast agent. IEEE Trans Ultrason Ferroelectr Freq Contro... Harmonic chirp imaging method for ultrasound contrast agent.Borsboom JM Chin CT Bouakaz A Versluis M de Jong N. IEEE Trans Ultrason Ferroelectr Freq Control. 2005 Feb 52(2)241-9. Quinary excitation method for pulse compression ultrasound measurements. Ultrasonics. 2008 Quinary excitation method for pulse compression ultrasound measurements.Cowell DM Freear S. Ultrasonics. 2008 Apr 48(2)98-108. Epub 2007 Nov 4. Short-time fractional Fourier methods for the time-frequency representation of chirp signals. J Acoust Soc Am. 2003 Short-time fractional Fourier methods for the time-frequency representation of chirp signals.Capus C Brown K. J Acoust Soc Am. 2003 Jun 113(6)3253-63. Review Use of modulated excitation signals in medical ultrasound. Part II Design and performance for medical imaging applications. IEEE Trans Ultrason Ferroelectr Freq Contro... Review Use of modulated excitation signals in medical ultrasound. Part II Design and performance for medical imaging applications.Misaridis T Jensen JA. IEEE Trans Ultrason Ferroelectr Freq Control. 2005 Feb 52(2)192-207. Review Use of modulated excitation signals in medical ultrasound. Part I Basic concepts and expected benefits. IEEE Trans Ultrason Ferroelectr Freq Contro... Review Use of modulated excitation signals in medical ultrasound. Part I Basic concepts and expected benefits.Misaridis T Jensen JA. IEEE Trans Ultrason Ferroelectr Freq Control. 2005 Feb 52(2)177-91. See reviews... See all... Recent activity Clear Turn Off Turn On Pulse compression of harmonic chirp signals using the fractional fourier transfo... Pulse compression of harmonic chirp signals using the fractional fourier transform.Ultrasound Med Biol. 2010 Jun 36(6)949-56. PubMed Your browsing activity is empty. Activity recording is turned off. Turn recording back on See more... You are here NCBI gt Literature gt PubMed Write to the Help Desk Simple NCBI Directory Getting Started NCBI Education NCBI Help Manual NCBI Handbook Training amp Tutorials Resources Chemicals amp BioassaysData amp SoftwareDNA amp RNADomains amp StructuresGenes amp ExpressionGenetics amp MedicineGenomes amp MapsHomologyLiteratureProteinsSequence AnalysisTaxonomyTraining amp TutorialsVariation Popular PubMed Nucleotide BLAST PubMed Central Gene Bookshelf Protein OMIM Genome SNP Structure Featured GenBank Reference Sequences Map Viewer Genome Projects Human Genome Mouse Genome Influenza Virus Primer-BLAST Sequence Read Archive NCBI Information About NCBI Research at NCBI NCBI Newsletter NCBI FTP Site NCBI on Facebook NCBI on Twitter NCBI on YouTube NIH DHHS USA.gov Copyright | Disclaimer | Privacy | Accessibility | Contact National Center for Biotechnology Information U.S. National Library of Medicine 8600 Rockville Pike Bethesda MD 20894 USA
less