Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"Acoustic Radiation Force"”.
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Acoustic Radiation Force Impulse Imaging of Myocardial Performance
… myocardial performance is myocardial stiffness. Acoustic radiation force impulse (ARFI) imaging has been demonstrated to be capable of visualizing variations in local stiffness within soft tissue. </p><p>In this thesis, the initial investigations into the visualization of myocardial performance …
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Volumetric Acoustic Radiation Force Impulse Imaging Using Intracardiac Echocardiography
… helicoid array transducers to perform ICE-based acoustic radiation force impulse (ARFI) imaging on multiple elevation planes at once, improving on current methods in terms of speed and ease-of-use.</p><p>The Siemens Acuson SC2000 ultrasound scanner was programmed with sequences to perform SWEI …
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Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging
… dissertation evaluates the hypothesis that Acoustic Radiation Force Impulse (ARFI) imaging can noninvasively identify lipid regions, that have been shown to increase a plaque's propensity to rupture, within carotid artery plaques <italic>in vivo</italic>. The work detailed herein describes …
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Mapping Myocardial Elasticity with Intracardiac Acoustic Radiation Force Impulse Methods
… on an intracardiac echocardiography transducer, acoustic radiation force methods may provide a useful means of characterizing the heart's elastic properties. Elasticity imaging may be of benefit for diagnosis and characterization of infarction and heart failure, as well as for guidance of …
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Acoustic Radiation Force Impulse-Driven Shear Wave Velocimetry in Cardiac Tissue
<p>Acoustic radiation force impulses (ARFI) have been used to generated transverse-traveling mechanical waves in various biological tissues. The velocity of these waves is related to a medium's stiffness and thus can offer useful diagnostic information. Consequently, shear wave velocimetry has the …
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Acoustic Radiation Force on a Fluid to Fluid Boundary by Phase Plate Focused Ultrasound
… the physics and applications of the ultrasonic radiation force at the interface between two immiscible fluids were investigated. These studies were performed using low-profile discrete-stepped lenses to the modify the phase of the incident radiation generating multiple field morphologies. In its …
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Assessment of Cardiac Function by Acoustic Radiation Force (ARF) Based Methods of Ultrasound Elastography
… measurement of cardiac function. </p><p>Acoustic radiation force (ARF) based ultrasound elastography techniques were developed in early 2000s and have been used to measure the static stiffness of tissue. These techniques are being used in the clinic for diagnosis of disorders and …
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Formation Process of Acoustophoretic Patterns
The acoustic radiation force is a nonlinear wave effect that exerts a non-zero time- averaged force on objects in the wave. In recent years, the acoustic radiation force has been widely explored for manipulating objects and small particles. These applications range from moving a few objects at a …
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Experimental and numerical investigation of steady-state and transient ultrasound directed self-assembly of spherical particles in a viscous medium
… directed self-assembly (DSA) utilizes the acoustic radiation force associated with a standing ultrasound wave field to organize particles dispersed in a fluid medium into specific patterns. The ability to tailor the organization and packing density of spherical particles using ultrasound …
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Super-Resolution Force Spectroscopy for Revealing Sub-nucleotide Motion in Ribosomal Frameshifting and DNA Methylation
… focuses on applying super-resolution force spectroscopy (SURFS) as a unique tool to resolve frameshifting products and intermediate states, with unprecedented resolution. Two different forms of forces have been studied, centrifugal force and acoustic radiation force. Using centrifugal …
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System identification and control of a miniature external mechanical vibration device towards clinical ultrasound shear wave elastography
An acoustic radiation force (ARF) is commonly used to generate shear waves in ultrasound systems for shear wave elastography (SWE). However, ARF requires complex hardware that produces thermal stresses in tissues and electronic components. External mechanical vibration (EMV) is less …
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Ultrasound shear wave elastography imaging with external mechanical vibration
… SWE systems generate shear waves using acoustic radiation force (ARF), which requires complex hardware and is therefore only available on high-end and premium systems. External mechanical vibration (EMV) is an alternative to induce shear waves without expensive electronics, which …
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Multi-frequency Ultrasound Directed Self-assembly
… directed self-assembly (DSA) relies on the acoustic radiation force associated with a standing ultrasound wave to organize particles dispersed in a fluid medium into specific patterns. State-of-the-art ultrasound DSA methods can only organize particles into (quasi-)periodic patterns, limited …
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Attachment mechanisms of a novel, targeted, lipid-based, ultrasound contrast agent
… successfully targeted to SK-Hep-1 cells using acoustic radiation force. In addition attachment of the microbubbles to SK-Hep-1 cells has been observed under 0.03Pa WSS in the Ibidi μ-slides.
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Novel Development of Super-Resolution Force Spectroscopy and Applications in Biological Systems
… however, has been rare. Super-resolution force spectroscopy (SURFS) was developed based on the integration of these two techniques, and it has unique biophysical applications in studying drug-DNA interactions and ribosomal translocations. I demonstrate that SURFS has a high force …
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Ultrasonic agitation for surface plasmon resonance biosensors
… is slow, particularly for large molecules. Acoustic streaming has been proposed as a solution to overcome the limitation of mixing in surface based biosensing devices.<br/><br/>This thesis reviews the effects of integrating ultrasonic technology into surface-based biosensors. The …
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Perturbed spherical objects in acoustic and fluid flow fields
In this study, the time averaged acoustic radiation force and drag on a small, nearly spherical object suspended freely in a stationary sound wave field in a compressible, low viscosity fluid is to be calculated. This problem has been solved for a spherical object, and it has many important …
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Novel Systems Physiology Instrumentation: Addressing Limitations in Heart Failure Reseearch
… for the failure of current HIFU technology: acoustic cavitation, acoustic radiation force, and discontinuous linear lesions. Improving our understanding of these mechanisms and their role in the creation of transmural lesions will facilitate the development of new HIFU technologies that would …
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