Adams, C, Cowell, DMJ, Nie, L et al. (2 more authors) (2017) A miniature HIFU excitation scheme to eliminate switching-induced grating lobes and nullify hard tissue attenuation. In: IEEE International Ultrasonics Symposium. 2017 IEEE International Ultrasonics Symposium (IUS), 06-09 Sep 2017, Washington, DC. IEEE ISBN 9781538633830
Abstract
Phased array transducers are increasingly prevalent in a therapeutic contex as they facilitate precise control of the beam intensity and focus. To produce enough acoustic energy for ablation, large and costly amplifiers are required. Miniaturised switched circuits provide an alternative that is both more cost effective and more efficient. However, the high Q factor and curved geometry of a therapeutic transducer lends itself to grating lobes that deposit energy in undesirable areas when driven with switched circuitry. In this work, harmonic reduction pulse with modulation (HRPWM) is applied to a simulation of a therapeutic array. An array was simulated along with a skull that varied in attenuation. A number of switching schemes were tested and where possible, their amplitude was adjusted to reduce pressure variation in the acoustic field after propagation through the skull. Of the switched schemes tested, HRPWM performed best; reducing harmonically induced grating lobes by 12 dB and limiting pressure field variance to 0.1 dB which increases intensity at the focal point and makes therapy more efficient.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 IEEE. This is an author produced version of a paper published in IEEE International Ultrasonics Symposium. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | frequency modulation, ultrasonic transducers, harmonic distortion, ultrasonic therapy |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) |
Funding Information: | Funder Grant number Wellcome Trust 105615/Z/14/Z |
Depositing User: | Symplectic Publications |
Date Deposited: | 26 Jan 2018 15:34 |
Last Modified: | 31 Jan 2018 15:23 |
Status: | Published |
Publisher: | IEEE |
Identification Number: | 10.1109/ULTSYM.2017.8091887 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:126657 |