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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Parametric array signal in confocal vibro-acoustography

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Baggio, Andre L. ; Kamimura, Hermes A. S. ; Henrique Lopes, J. ; Carneiro, Adilton A. O. ; Silva, Glauber T.
Total Authors: 5
Document type: Journal article
Source: APPLIED ACOUSTICS; v. 126, p. 143-148, NOV 2017.
Web of Science Citations: 2

In vibro-acoustography imaging systems, two ultrasound beams of distinct frequencies are employed to form an image of biological tissue at the difference-frequency. Three mechanisms contribute to the difference-frequency pressure, namely induced acoustic emission by a time-modulated radiation force, parametric array signal due to the superposition the beams along the propagation direction, and interaction of sound-with-sound effects. We analyze the strength of parametric array signal generated by a vibro-acoustography system composed of a two-element confocal transducer driven by two sinusoidal signals with center frequency 3.2 MHz. A 1-mm diameter tungsten sphere, placed at the transducer's focus, is used as the target object. We measure the difference-frequency pressure in water at room temperature with a calibrated hydrophone. The measurements are taken along the beam's axis in the farfield. In this configuration, the difference-frequency signal is mostly due to the parametric array phenomenon. Additionally, the acoustic emission and interaction of sound-with-sound signal levels are theoretically estimated. They are, respectively, 33 and 20 dB below the parametric array signal. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 11/10809-6 - Sonothrombolysis by focused and modulated acoustic radiation force using double beam
Grantee:Hermes Arytto Salles Kamimura
Support type: Scholarships in Brazil - Doctorate