Remotely induced shear acoustic waves in tissues by radiation force of focused ultrasound.

1996 ◽  
Vol 99 (4) ◽  
pp. 2465-2500 ◽  
Author(s):  
Armen P. Sarvazyan ◽  
Oleg V. Rudenko
Keyword(s):  
Acoustic Waves ◽  
Focused Ultrasound ◽  
Radiation Force

The radiation force on a rigid sphere in standing surface acoustic waves

2018 ◽  
Vol 124 (10) ◽  
pp. 104503 ◽  
Author(s):  
Shen Liang ◽  
Wang Chaohui ◽  
Hu Qiao
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Radiation Force ◽  
Rigid Sphere

scholarly journals Measurement and modeling of acoustic radiation force of focused ultrasound beam on an elastic sphere in water

2017 ◽  
Author(s):  
Maria Karzova ◽  
Anastasia Nikolaeva ◽  
Sergey Tsysar ◽  
Vera Khokhlova ◽  
Oleg Sapozhnikov
Keyword(s):  
Focused Ultrasound ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Elastic Sphere ◽  
Ultrasound Beam

scholarly journals Acoustophoretic Control of Microparticle Transport Using Dual-Wavelength Surface Acoustic Wave Devices

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 52 ◽  
Author(s):  
Jin-Chen Hsu ◽  
Chih-Hsun Hsu ◽  
Yeo-Wei Huang
Keyword(s):  
Particle Motion ◽  
Acoustic Waves ◽  
Acoustic Pressure ◽  
Acoustic Radiation ◽  
Surface Acoustic Waves ◽  
Microfluidic Channel ◽  
Radiation Force ◽  
Dual Wavelength ◽  
Single Frequency ◽  
Motion Trajectories

We present a numerical and experimental study of acoustophoretic manipulation in a microfluidic channel using dual-wavelength standing surface acoustic waves (SSAWs) to transport microparticles into different outlets. The SSAW fields were excited by interdigital transducers (IDTs) composed of two different pitches connected in parallel and series on a lithium niobate substrate such that it yielded spatially superimposed and separated dual-wavelength SSAWs, respectively. SSAWs of a singltablee target wavelength can be efficiently excited by giving an RF voltage of frequency determined by the ratio of the velocity of the SAW to the target IDT pitch (i.e., f = cSAW/p). However, the two-pitch IDTs with similar pitches excite, less efficiently, non-target SSAWs with the wavelength associated with the non-target pitch in addition to target SSAWs by giving the target single-frequency RF voltage. As a result, dual-wavelength SSAWs can be formed. Simulated results revealed variations of acoustic pressure fields induced by the dual-wavelength SSAWs and corresponding influences on the particle motion. The acoustic radiation force in the acoustic pressure field was calculated to pinpoint zero-force positions and simulate particle motion trajectories. Then, dual-wavelength SSAW acoustofluidic devices were fabricated in accordance with the simulation results to experimentally demonstrate switching of SSAW fields as a means of transporting particles. The effects of non-target SSAWs on pre-actuating particles were predicted and observed. The study provides the design considerations needed for the fabrication of acoustofluidic devices with IDT-excited multi-wavelength SSAWs for acoustophoresis of microparticles.

Radiation force on absorbing targets and power measurements of a high intensity focused ultrasound (HIFU) source

2010 ◽  
Vol 53 (10) ◽  
pp. 1780-1787 ◽  
Author(s):  
ZuWen Qian ◽  
ZheMin Zhu ◽  
ShiGong Ye ◽  
WenHua Jiang ◽  
HouQing Zhu ◽  
...  
Keyword(s):  
High Intensity ◽  
Focused Ultrasound ◽  
Radiation Force ◽  
High Intensity Focused Ultrasound ◽  
Power Measurements

scholarly journals Microscale concert hall acoustics to produce uniform ultrasound stimulation for targeted sonogenetics in hsTRPA1-transfected cells

2021 ◽  
Author(s):  
Aditya Vasan ◽  
Florian Allein ◽  
Marc Duque ◽  
Uri Magaram ◽  
Nicholas Boechler ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Focused Ultrasound ◽  
Electrical Response ◽  
Fold Increase ◽  
Normal Brain ◽  
Ultrasound Exposure ◽  
Ultrasound Stimulation ◽  
Normal Brain Function ◽  
Ultrasound Intensity ◽  
The Brain

The field of ultrasound neuromodulation has rapidly developed over the past decade, a consequence of the discovery of strain-sensitive structures in the membrane and organelles of cells extending into the brain, heart, and other organs. Notably, clinical trials are underway for treating epilepsy using focused ultrasound to elicit an organized local electrical response. A key limitation to this approach is the formation of standing waves within the skull. In standing acoustic waves, the maximum ultrasound intensity spatially varies from near zero to double the mean in one half a wavelength, and can lead to localized tissue damage and disruption of normal brain function while attempting to evoke a broader response. This phenomenon also produces a large spatial variation in the actual ultrasound exposure in tissue, leading to heterogeneous results and challenges with interpreting these effects. One approach to overcome this limitation is presented herein: transducer-mounted diffusers that result in spatiotemporally incoherent ultrasound. The signal is numerically and experimentally quantified in an enclosed domain with and without the diffuser. Specifically, we show that adding the diffuser leads to a two-fold increase in ultrasound responsiveness of hsTRPA1 transfected HEK cells. Furthermore, we demonstrate the diffuser allow us to produce an uniform spatial distribution of pressure in the rodent skull. Collectively, we propose that our approach leads to a means to deliver uniform ultrasound into irregular cavities for sonogenetics.

scholarly journals Measurement of the acoustic streaming pattern in a standing surface acoustic wave field

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Sebastian Sachs ◽  
Christian Cierpka ◽  
Jörg König
Keyword(s):  
Wave Field ◽  
Acoustic Waves ◽  
Acoustic Radiation ◽  
Electrical Power ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Radiation Force ◽  
Flow Measurements

The application of standing surface acoustic waves (sSAW) has enabled the development of many flexible and easily scalable concepts for the fractionation of particle solutions in the field of microfluidic lab-ona-chip devices. In this context, the acoustic radiation force (ARF) is often employed for the targeted manipulation of particle trajectories, whereas acoustically induced flows complicate efficient fractionation in many systems [Sehgal and Kirby (2017)]. Therefore, a characterization of the superimposed fluid motion is essential for the design of such devices. The present work focuses on a structural analysis of the acousticallyexcited flow, both in the center and in the outer regions of the standing wave field. For this, experimental flow measurements were conducted using astigmatism particle tracking velocimetry (APTV) [Cierpka et al. (2010)]. Through multiple approaches, we address the specific challenges for reliable velocity measurements in sSAW due to limited optical access, the influence of the ARF on particle motion, and regions of particle depletion caused by multiple pressure nodes along the channel width and height. Variations in frequency, channel geometry, and electrical power allow for conclusions to be drawn on the formation of a complex, three-dimensional vortex structure at the beginning and end of the sSAW.

scholarly journals Unsteady particle motion in an acoustic standing wave field

2019 ◽  
Author(s):  
S. Wanga ◽  
J. S. Allen ◽  
A. M. Ardekani
Keyword(s):  
Wave Field ◽  
Standing Wave ◽  
Particle Motion ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Particle Interaction ◽  
Inertial Force ◽  
Radiation Force ◽  
Acoustic Standing Wave ◽  
Standing Wave Field

The acoustic-based separation has attracted considerable attention in biomedical research, such as sorting of cells and particles. Current design principles used for acoustic systems are based on the steady Stokes theory, equating the Stokes drag with the primary radiation force. However, this approach is not valid for large cells/particles or in the presence of particle–particle interaction. In this work,we analytically examine unsteady inertial affects and particle–particle hydrodynamic interaction on the particle motion in a viscous fluid in the presence of an acoustic standing wave field. Comparing our results to the steady Stokes theory, we find that the unsteady inertial force decreases the particle’s velocity, while particle–particle interaction enhances it. For a particular acoustic-based separation approach ‘tilted-angle standing surface acoustic waves (taSSAW)’, we find that both effects of unsteady inertial force and particle–particle interaction are evident and should be considered for O(10μm) particles or larger. Our study improves the current predictions of particle trajectory in acoustic-based separation devices.

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