Variable frequency field conjugate lenses for ultrasound hyperthermia

Author

Lalonde, Ron ; Hunt, John W.

Author_Institution

Dept. of Med. Phys., Hamilton Regional Cancer Centre, Ont., Canada

Volume

42

Issue

5

fYear

1995

Firstpage

825

Lastpage

831

Abstract

This paper describes variable frequency focusing with field conjugate lenses designed to mimic the multiple-focusing capabilities of large two-dimensional phased arrays. Simulations, experiments, and Fresnel diffraction analysis are used to show that both the size and the depth of a field conjugate lens focus may vary with frequency. Examples are given for field conjugate lens focusing with planar transducers, focused transducers, and ordinary refracting lenses.<>

Keywords

biomedical ultrasonics; hyperthermia; lenses; radiation therapy; ultrasonic diffraction; ultrasonic focusing; Fresnel diffraction analysis; field conjugate lens focus; focused transducers; large two-dimensional phased arrays; multiple-focusing capabilities; ordinary refracting lenses; planar transducers; simulations; ultrasound hyperthermia; variable frequency field conjugate lenses; variable frequency focusing; Acoustic transducers; Biomedical transducers; Frequency; Hyperthermia; Lenses; Medical treatment; Optical design; Phased arrays; Ultrasonic imaging; Ultrasonic transducers;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/58.464838

Filename

464838