Forming acoustic attraction force to concentrate microbubbles in flow using a matrix array transducer

Hosaka, Naoto; Miyazawa, Shinya; Sawaguchi, Toi; Koda, Ren; Onogi, Shinya; Mochizuki, Takashi; Masuda, Kohji

doi:10.1109/ultsym.2014.0442

Cited by 4 publications

(2 citation statements)

References 8 publications

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“…To generate a local energy density difference near a thin catheter, we have generated multiple focal points to induce microbubbles between these focal points. 31) Bjerknes force is proportional to the slope of sound pressure; therefore, microbubbles are concentrated in an acoustic field between two focal points. Using multiple sound sources simultaneously, it is possible to realize a steeper slope between the focal points with phase variation.…”

Section: Generation Of Two Focal Points Of Opposite Phasesmentioning

confidence: 99%

Thin catheter bending in the direction perpendicular to ultrasound propagation using two-dimensional array transducer

Suzuki¹,

Mochizuki²,

Ushimizu³

et al. 2017

Jpn. J. Appl. Phys.

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Although we have already experimented on the bending of a thin catheter with acoustic radiation force using a single transducer, it is necessary to develop a method of bending a catheter in an arbitrary direction because the installation position of ultrasound transducers on a body surface is limited for application to various shapes of in vivo blood vessels. Therefore, we examined the bending of a thin catheter in the direction perpendicular to ultrasound propagation using a two-dimensional array transducer (1 MHz), which realizes not only the temporospatial design but also the dynamic variation of acoustic fields. Forming two focal points with opposite phases, where the amplitudes of the two points instantaneously have the positive and negative relationship, we confirmed the bending of a thin catheter in the direction perpendicular to ultrasound propagation. We used a thin catheter (diameter, 200 µm; length, 50 mm) to obtain the maximum displacement of 220 µm, where the displacement was proportional to the square of the maximum sound pressure and the duty ratio. From these results, the acoustic energy densities observed in front of and behind the catheter are dominant for the bending of the thin catheter independent of ultrasound propagation. We also found that the distance between two focal points may improve the bending performance without requiring a precise position setting.

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Section: Generation Of Two Focal Points Of Opposite Phasesmentioning

confidence: 99%

Thin catheter bending in the direction perpendicular to ultrasound propagation using two-dimensional array transducer

Suzuki¹,

Mochizuki²,

Ushimizu³

et al. 2017

Jpn. J. Appl. Phys.

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“…The acoustic radiation force (ARF) [50] is proportional to the (momentum) transport cross-section (TCS) of the structure [51], which is also known as diffusion cross-section [52]. Mechanical manipulation of small particles using ultrasonic beams is a promising tool for non-invasive surgery [53] and various microfluidic [54,55] and biomedical [56,57] technologies. Engineering acoustic TCSs of manmade structures comparable in size with the wavelength presents an interesting challenge for such technologies.…”

Section: Introductionmentioning

confidence: 99%

Three forms of omnidirectional acoustic invisibility engineered using fast elastodynamic transfer-matrix method

Bowen¹,

Urzhumov²

2016

J. Opt.

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Acoustic metamaterial structures with discrete and continuous rotational symmetries attract interest of theorists and engineers due to the relative simplicity of their design and fabrication. They are also likely candidates for omnidirectional acoustic cloaking and other transformationacoustical novelties. In this paper, we employ a stratified description of such structures, and develop the theory and an efficient symbolic/numerical algorithm for analyzing the scattering properties of such structures immersed in homogeneous fluid environments. The algorithm calculates the partial scattering amplitudes and the related scattering phases for an arbitrary layered distribution of acoustic material properties. The efficiency of the algorithm enables us to find approximate solutions to certain inverse scattering problems through quasi-global optimization. The scattering problems addressed here are the three forms of cloaking: (1) extinction cross-section suppression, the canonical form of cloaking, (2) monostatic sonar invisibility (backscattering suppression), and (3) acoustic force cloaking (transport cross-section suppression). We also address the efficiency-bandwidth tradeoff and design approximate cloaks with wider bandwidth using a new optimization formulation.

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Thin catheter bending in arbitrary direction using tempo-spatial variation of acoustic distribution

Hosaka

Ushimizu

Suzuki

et al. 2017

2017 10th Biomedical Engineering International Conference (BMEiCON)

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Forming acoustic attraction force to concentrate microbubbles in flow using a matrix array transducer

Cited by 4 publications

References 8 publications

Thin catheter bending in the direction perpendicular to ultrasound propagation using two-dimensional array transducer

Thin catheter bending in the direction perpendicular to ultrasound propagation using two-dimensional array transducer

Three forms of omnidirectional acoustic invisibility engineered using fast elastodynamic transfer-matrix method

Thin catheter bending in arbitrary direction using tempo-spatial variation of acoustic distribution

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