scholarly journals Study of nonlinear acoustic field of high intensity focused ultrasound by the fractional wave

2013 ◽  
Vol 62 (5) ◽  
pp. 054301
Author(s):  
Sun Jian-Ming ◽  
Yu Jie ◽  
Guo Xia-Sheng ◽  
Zhang Dong
Keyword(s):  
Acoustic Field ◽  
High Intensity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Nonlinear Acoustic

scholarly journals Acoustic-electroelastic modeling of piezoelectric disks in high-intensity focused ultrasound power transfer systems

2020 ◽  
pp. 1045389X2097547
Author(s):  
Aarushi Bhargava ◽  
Shima Shahab
Keyword(s):  
Wave Propagation ◽  
Acoustic Field ◽  
High Intensity ◽  
Focused Ultrasound ◽  
Finite Size ◽  
High Intensity Focused Ultrasound ◽  
Power Transfer ◽  
Acoustic Structure ◽  
Nonlinear Acoustic ◽  
Ultrasound Power

Contactless ultrasound power transfer (UPT) has emerged as one of the promising techniques for wireless power transfer. Physical processes supporting UPT include the vibrations at a transmitting/acoustic source element, acoustic wave propagation, piezoelectric transduction of elastic vibrations at a receiving element, and acoustic-structure interactions at the surfaces of the transmitting and receiving elements. A novel mechanism using a high-intensity focused ultrasound (HIFU) transmitter is proposed for enhanced power transfer in UPT systems. The HIFU source is used for actuating a finite-size piezoelectric disk receiver. The underlying physics of the proposed system includes the coupling of the nonlinear acoustic field with structural responses of the receiver, which leads to spatial resonances and the appearance of higher harmonics during wave propagation in a medium. Acoustic nonlinearity due to wave kinematics in the HIFU-UPT system is modeled by taking into account the effects of diffraction, absorption, and nonlinearity in the medium. Experimentally-validated acoustic-structure interaction formulation is employed in a finite element based multiphysics model. The results show that the HIFU high-level excitation can cause disproportionately large responses in the piezoelectric receiver if the frequency components in the nonlinear acoustic field coincide with the resonant frequencies of the receiver.

Acoustic field characterization of a clinical magnetic resonance-guided high-intensity focused ultrasound system inside the magnet bore

2017 ◽  
Vol 44 (9) ◽  
pp. 4890-4899 ◽  
Author(s):  
Satya V.V.N. Kothapalli ◽  
Michael B. Altman ◽  
Ari Partanen ◽  
Leighton Wan ◽  
H. Michael Gach ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Acoustic Field ◽  
High Intensity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Ultrasound System

scholarly journals Effects of Nonlinear Propagation of Focused Ultrasound on the Stable Cavitation of a Single Bubble

Acoustics ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 14-34 ◽  
Author(s):  
Marjan Bakhtiari-Nejad ◽  
Shima Shahab
Keyword(s):  
Acoustic Field ◽  
High Intensity ◽  
Focused Ultrasound ◽  
Bubble Dynamics ◽  
Translational Motion ◽  
High Intensity Focused Ultrasound ◽  
Nonlinear Propagation ◽  
Resonance Excitation ◽  
Acoustic Nonlinearity ◽  
Shape Oscillations

Many biomedical applications such as ultrasonic targeted drug delivery, gene therapy, and molecular imaging entail the problems of manipulating microbubbles by means of a high-intensity focused ultrasound (HIFU) pressure field; namely stable cavitation. In high-intensity acoustic field, bubbles demonstrate translational instability, the well-known erratic dancing motion, which is caused by shape oscillations of the bubbles that are excited by their volume oscillations. The literature of bubble dynamics in the HIFU field is mainly centered on experiments, lacking a systematic study to determine the threshold for shape oscillations and translational motion. In this work, we extend the existing multiphysics mathematical modeling platform on bubble dynamics for taking account of (1) the liquid compressibility which allows us to apply a high-intensity acoustic field; (2) the mutual interactions of volume pulsation, shape modes, and translational motion; as well as (3) the effects of nonlinearity, diffraction, and absorption of HIFU to incorporate the acoustic nonlinearity due to wave kinematics or medium—all in one model. The effects of acoustic nonlinearity on the radial pulsations, axisymmetric modes of shape oscillations, and translational motion of a bubble, subjected to resonance and off-resonance excitation and various acoustic pressure, are examined. The results reveal the importance of considering all the involved harmonics and wave distortion in the bubble dynamics, to accurately predict the oscillations, translational trajectories, and the threshold for inertial (unstable) cavitation. This result is of interest for understanding the bubble dynamical behaviors observed experimentally in the HIFU field.

260: High Intensity Focused Ultrasound Combined with Endocrine Therapy in Treating High or Intermediate Risk Prostate Cancer

2006 ◽  
Vol 175 (4S) ◽  
pp. 86-86
Author(s):  
Makoto Sumitomo ◽  
Junichi Asakuma ◽  
Yasumasa Hanawa ◽  
Kazuhiko Nagakura ◽  
Masamichi Hayakawa
Keyword(s):  
Prostate Cancer ◽  
Endocrine Therapy ◽  
High Intensity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Intermediate Risk ◽  
Risk Prostate Cancer
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