Phase aberration correction in two dimensions using a deformable array transducer.

Published

Journal Article

Phase aberrations due to tissue inhomogeneities degrade medical ultrasound images by disrupting the ultrasound beam focus. Currently, phase correction algorithms are implemented by adjusting the electronic phase delays uses to steer and focus the ultrasound beam. This means that a two-dimensional array is necessary to completely correct two-dimensional aberrations in tissue. However, two-dimensional arrays are a complex option due to their large number of elements and poor sensitivity. Instead of using a full two-dimensional array, a new technique is proposed, similar to one used in adaptive optics, which used a deformable transducer of significantly fewer channels for two-dimensional phase correction. Phase correction in azimuth is achieved by altering the electronic phase delay of the element. However, phase correction in elevation is achieved by tilting the element in elevation with a piezoelectric actuator. Comparison of simulations of the new phase correction transducer versus the conventional phase correction technique have shown that a deformable 1 x N or 2 x N transducer can approach the image quality of a 4 x N two-dimensional array or greater. A prototype 1 x 32 array with eight low frequency piezoelectric actuators has been constructed such that every four ultrasonic transducer elements in azimuth are mounted on one independently controlled actuator. This prototype transducer was used to test the ability of a deformable array to produce real time phased array scans and to simulate on-line phase correction by tilting the elements in the elevation direction.

Full Text

Duke Authors

Cited Authors

  • Ries, LL; Smith, SW

Published Date

  • July 1995

Published In

Volume / Issue

  • 17 / 3

Start / End Page

  • 227 - 247

PubMed ID

  • 8772265

Pubmed Central ID

  • 8772265

Electronic International Standard Serial Number (EISSN)

  • 1096-0910

International Standard Serial Number (ISSN)

  • 0161-7346

Digital Object Identifier (DOI)

  • 10.1177/016173469501700303

Language

  • eng