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A Phased Array Acoustic Imaging System for Medical Use

  • H. Edward Karrer
  • J. Fleming Dias
  • John D. Larson
  • Richard D. Pering
  • Samuel H. Maslak
  • David A. Wilson
Part of the Acoustical Imaging book series (ACIM, volume 10)

Abstract

An experimental linear phased array acoustic imaging system has been developed for cardiac, obstetric, and radiological use. This is a real time, pulsed B scan system using either a 2.5 MHz or a 3.5 MHz hand held transducer. The display format is a sector scan with dimensions of 90° × 24 cm and the system is dynamically focussed. The system uses an analog heterodyne architecture to greatly simplify the electronics for a densely packed array and to allow use with transducers of different frequencies. With a 20 mm aperture segmented into 64 elements, at 2.5 MHz, the system achieves a 6 dB resolution at 7 cm in water of 2.5 mm in azimuth, 1 mm in range, and 3.5 mm in elevation. Emphasis was put on a system with wide dynamic range; side lobe levels of the array beam plot less than −65 dB have been achieved over the sector. A digital scan converter is used to convert the sector scan to a raster display and for image processing. Images will be shown to demonstrate system performance.

Keywords

Element Spacing Side Lobe Acoustic Pulse Side Lobe Level Final Array 
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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Copyright information

© Plenum Press, New York 1982

Authors and Affiliations

  • H. Edward Karrer
    • 1
  • J. Fleming Dias
    • 1
  • John D. Larson
    • 1
  • Richard D. Pering
    • 1
  • Samuel H. Maslak
    • 2
  • David A. Wilson
    • 3
  1. 1.Hewlett-Packard LaboratoriesPalo AltoUSA
  2. 2.AcusonLos AltosUSA
  3. 3.SRI InternationalMenlo ParkUSA

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