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Nonlinear and linear propagation of diagnostic ultrasound pulses
Ultrasound in Medicine & Biology, 1999The effect of nonlinear propagation in fluid followed by soft tissue was studied both theoretically and experimentally for a most crucial case in obstetrical ultrasonography. For this purpose, short pressure pulses, with the duration time of 1.3 micros and a carrier frequency of 3 MHz, radiated by a concave transducer into water, with maximum ...
L, Filipczyński +3 more
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Nonlinearities in the bioeffects of ultrasound
The Journal of the Acoustical Society of America, 1998Biological effects of ultrasound involve nonlinear phenomena (1) in the propagation of sound itself, (2) in the generation of acoustic cavitation, and (3) in the biochemistry, physiology, and pathology of the biological system. Most nonthermal bioeffects of interest to users of diagnostic ultrasound require acoustic pressures great enough that the wave
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Nonlinear coded excitation method for ultrasound contrast imaging
Ultrasound in Medicine & Biology, 2003Coded excitation with compression on receive is used in medical ultrasound (US) imaging to increase signal-to-noise ratio (SNR) and penetration depth. We performed a computer simulation study to investigate if chirped pulse excitation can be applied in US contrast agent imaging to increase SNR and contrast-to-tissue ratio (CTR) and, thus, reduce ...
Borsboom, J., Chin, C., de Jong, N.
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Nonlinear resonant ultrasound for damage detection
AIP Conference Proceedings, 2000Nonlinear resonance measurements provide the means to make very precise determination of material properties (e.g., modulus) as well as to ascertain damage. Nonlinear resonance measurements made on concrete cores show many similarities to measurements made on earth materials. Resonance peak shifts and memory effects can both be used to ascertain damage.
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Nonlinear bulk elasticity imaging using dual frequency ultrasound
The Journal of the Acoustical Society of America, 2019The nonlinear acoustic bulk properties of tissue, e.g., the coefficient of nonlinearity, βn, or the nonlinear bulk elasticity, βp=βnκ0, have been shown to be promising parameters for tissue characterization due to their sensitivity to tissue structure.
Johannes, Kvam +4 more
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Nonlinear propagation of ultrasound in superfluid3He
Journal of Statistical Physics, 1985After introducing the physics of sound propagation in normal and superfluid3He, nonlinear phenomena are discussed. These bear close resemblance to optical effects, including saturation of the absorption, amplitude dependence of the group velocity, pulse break-up, and pulse compression.
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Nonlinear viscoelastic properties of tissue assessed by ultrasound
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2006A technique to assess qualitatively the presence of higher-order viscoelastic parameters is presented. Low-frequency, monochromatic elastic waves are emitted into the material via an external vibrator. The resulting steady-state motion is detected in real time via an ultra fast ultrasound system using classical, one-dimensional (1-D) ultrasound speckle
Ralph, Sinkus +7 more
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Moderately nonlinear ultrasound propagation in blood-mimicking fluid
Ultrasound in Medicine & Biology, 2004In medical diagnostic ultrasound (US), higher than-in-water nonlinearity of body fluids and tissue usually does not produce strong nonlinearly distorted waves because of the high absorption. The relative influence of absorption and nonlinearity can be characterized by the Gol'dberg number Gamma. There are two limiting cases in nonlinear acoustics: weak
Nikolay A, Kharin, D Geoffrey, Vince
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Nonlinear pulsing schemes for diagnostic ultrasound.
The Journal of the Acoustical Society of America, 2009With the introduction of ultrasound contrast agents and the development of tissue harmonic imaging (THI), nonlinear acoustics has become a major research direction in diagnostic ultrasound. In THI an image is formed from the nonlinear components (due to nonlinear propagation) of the backscattered signal.
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Nonlinearities in ultrasonic flow measurement
Flow Measurement and Instrumentation, 2008Abstract The governing equations of flow acoustics including nonlinearities are solved and analyzed in terms of ultrasonic flow-measurement properties. The effect of nonlinearities for sound propagation is expected to be most significant for gas-flow measurement applications as gas-sound speeds are much smaller while fluid flows generally are much ...
Willatzen, Morten, Kamath, Hemant
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