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Ultrasound Transducer Characterization Using Angular Spectrum Backpropagation

  • Mark E. Schafer
  • Peter A. Lewin
Part of the Acoustical Imaging book series (ACIM, volume 18)

Abstract

This paper presents a measurement method for analyzing the surface velocity patterns of ultrasonic transmitters, based on the angular spectrum backpropagation method of wavefield analysis. With this approach, acoustic propagation between parallel planes is modelled by taking the two-dimensional Fourier transform of the wavefield, multiplying each element in the spatial frequency domain by the appropriate phase factor, and inverse transforming the resultant angular spectrum. The basic method was expanded from the monochromatic case to the wideband pulsed case, which is more typical of diagnostic instrumentation. An experimental system was designed built to measure the acoustic fields from various transducers, including single element and multi-element phased arrays. Results are given for circular planar, circular focussed, and rectangular phase steered transducers. The results demonstrate the method’s ability to reconstruct the surface velocity distributions of complex ultrasonic radiators.

Keywords

Angular Spectrum Phase Plot Acoustic Source Continuous Wave Mode Phase Array Transducer 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    J.W. Goodman, Introduction to Fourier Optics, (McGraw-Hill, New York), 1968.Google Scholar
  2. 2.
    F.P. Higgins, S. J. Norton, and M. Linzer, “Optical Interferometric Visualization and Computerized Reconstruction of Ultrasonic Fields,” JASA, 68(4), pp 1169–1176, 1980.CrossRefGoogle Scholar
  3. 3.
    P.R Stepanishen. and K.C. Benjamin, “Forward and Backward Projection of Acoustic Fields Using FFT Methods,” JASA, 71(4), pp. 803–812, 1982.CrossRefGoogle Scholar
  4. 4.
    M.M. Sondhi, “Reconstruction of Objects from Their Sound-Diffraction Patterns,” JASA, 46(5), pp. 1158–1164, 1969.CrossRefGoogle Scholar
  5. 5.
    M.E. Schafer, P.A. Lewin, and J.M. Reid, “A New Technique for Characterizing Transducers in Inhomogeneous Media,” in Acoustical Holography, Vol. 15, H. Jones, ed. (Plenum, New York) pp. 135–146, 1987.Google Scholar
  6. 6.
    M.E. Schafer, “Transducer Characterization in Inhomogeneous Media Using the Angular Spectrum Method,” Ph.D. Thesis, Drexel University, 1988.Google Scholar
  7. 7.
    J.P. Powers, “Computer Simulation of Linear Acoustic Diffraction,” in Acoustical Holography, Vol. 7, Kesler, L.W., ed. (Plenum, New York) pp. 193–205, 1976.Google Scholar
  8. 8.
    E.G. Williams and J.D. Maynard, “Numerical Evaluation of the Rayleigh Integral for Planar Radiators Using the FFT,” JASA, 72(6), pp. 2020–2030, 1982.MATHCrossRefGoogle Scholar
  9. 9.
    M.E. Schafer and P.A. Lewin, “A Computerized System for Measuring the Acoustic Output from Diagnostic Ultrasound Equipment,” IEEE Trans. Ultrasonics, Ferroelectrics, and Freqency Control, UFFC-35(2), pp. 102–109, 1988.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • Mark E. Schafer
    • 1
  • Peter A. Lewin
    • 2
  1. 1.International Sonic TechnologiesHorshamUSA
  2. 2.Department of Electrical and Computer Engineering, Biomedical Engineering and Science InstituteDrexel UniversityPhiladelphiaUSA

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