The mechanical and thermal effects of focused ultrasound in a model biological material

2005 ◽  
Vol 117 (4) ◽  
pp. 2347-2355 ◽  
Author(s):  
Feng Feng ◽  
Ajit Mal ◽  
Michael Kabo ◽  
Jeffrey C. Wang ◽  
Yoseph Bar-Cohen
Keyword(s):  
Biological Material ◽  
Thermal Effects ◽  
Focused Ultrasound

Modeling of nonlinear shock wave propagation and thermal effects in high‐intensity focused ultrasound fields.

2010 ◽  
Vol 127 (3) ◽  
pp. 1827-1827 ◽  
Author(s):  
Vera A. Khokhlova ◽  
Olga V. Bessonova ◽  
Mikhail V. Averiyanov ◽  
Joshua E. Soneson ◽  
Robin O. Cleveland
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
High Intensity ◽  
Thermal Effects ◽  
Focused Ultrasound ◽  
Shock Wave Propagation ◽  
High Intensity Focused Ultrasound ◽  
Nonlinear Shock

MPI Parallelization for Two-Way Coupled Euler-Lagrange Simulation of Microbubble Enhanced HIFU

2021 ◽  
Author(s):  
Jingsen Ma ◽  
Aswin Gnanaskandan ◽  
Chao-Tsung Hsiao ◽  
Georges L. Chahine
Keyword(s):  
Thermal Effects ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Tissue Ablation ◽  
Computational Domain ◽  
Tumor Treatment ◽  
Time Step ◽  
Thermal Fields ◽  
Before And After ◽  
Gas Volume

Abstract Microbubble enhanced High Intensity Focused Ultrasound (HIFU) is of great interest to tissue ablation for tumor treatment such as in liver and brain cancers, where microbubbles are injected to the targeted region to promote focal heating while reducing pre-focal damage. To accurately characterize the acoustic and thermal fields during this process, a compressible Euler-Lagrange model is used, and a domain decomposition based MPI parallelization scheme is developed for its speedup. The Eulerian computational domain is subdivided into several subdomains, and the Lagrangian bubbles are subdivided based on their locations corresponding to each subdomain. During each time step, MPI processors, each handling one subdomain, are sequentially used to execute 1) the fluid, and 2) bubble computations, 3) followed by the coupling which maps the void fraction from Lagrangian bubbles into Eulerian grids. Steps 1) and 2) are relatively straightforward by routinely following regular MPI procedures. However, step 3) becomes challenging as a bubble near borders needs to spread its effects to cells in different subdomains. This is addressed by a special utilization of ghost cells surrounding each fluid subdomain, which allows bubbles to spread their void effects across subdomain edges without the need of directly exchanging bubble information between subdomains and significantly increasing overhead. This is verified by gas volume conservation before and after spreading the bubble effects. Bubbles' thermal effects are handled in a similar way. This parallelization scheme is validated and illustrated on a typical microbubble enhanced HIFU problem, followed by parallelization scaling tests and efficiency analysis.

scholarly journals In VitroDemonstration of Focused Ultrasound Thrombolysis Using Bifrequency Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Izella Saletes ◽  
Bruno Gilles ◽  
Vincent Auboiroux ◽  
Nadia Bendridi ◽  
Rares Salomir ◽  
...  
Keyword(s):  
Thermal Effects ◽  
Focused Ultrasound ◽  
Power Level ◽  
Pharmacological Agent ◽  
Inertial Cavitation ◽  
Blood Clots ◽  
Before And After ◽  
Passive Acoustic ◽  
Cavitation Activity

Focused ultrasound involving inertial cavitation has been shown to be an efficient method to induce thrombolysis without any pharmacological agent. However, further investigation of the mechanisms involved and further optimization of the process are still required. The present work aims at studying the relevance of a bifrequency excitation compared to a classical monofrequency excitation to achieve thrombolysis without any pharmacological agent.In vitrohuman blood clots were placed at the focus of a piezoelectric transducer. Efficiency of the thrombolysis was assessed by weighing each clot before and after sonication. The efficiencies of mono- (550 kHz) and bifrequency (535 and 565 kHz) excitations were compared for peak power ranging from 70 W to 220 W. The thrombolysis efficiency appears to be correlated to the inertial cavitation activity quantified by passive acoustic listening. In the conditions of the experiment, the power needed to achieve 80% of thrombolysis with a monofrequency excitation is reduced by the half with a bifrequency excitation. The thermal effects of bifrequency and monofrequency excitations, studied using MR thermometry measurements in turkey muscle samples where no cavitation occurred, did not show any difference between both types of excitations when using the same power level.

Thermal effects of focused ultrasound on the brain: determination with MR imaging.

Radiology ◽  
1997 ◽  
Vol 204 (1) ◽  
pp. 247-253 ◽  
Author(s):  
K Hynynen ◽  
N I Vykhodtseva ◽  
A H Chung ◽  
V Sorrentino ◽  
V Colucci ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Thermal Effects ◽  
Focused Ultrasound ◽  
The Brain

scholarly journals The inhibitory thermal effects of focused ultrasound on an identified, single motoneuron

eNeuro ◽  
2021 ◽  
pp. ENEURO.0514-20.2021
Author(s):  
Morgan N. Collins ◽  
Wynn Legon ◽  
Karen A. Mesce
Keyword(s):  
Thermal Effects ◽  
Focused Ultrasound
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