Search Results - "WEAR, Keith A"

Time-domain separation of interfering waves in cancellous bone using bandlimited deconvolution: simulation and phantom study by Wear, Keith A

“…In through-transmission interrogation of cancellous bone, two longitudinal pulses ("fast" and "slow" waves) may be generated. Fast and slow wave properties…”
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Variation of High-Intensity Therapeutic Ultrasound (HITU) Pressure Field Characterization: Effects of Hydrophone Choice, Nonlinearity, Spatial Averaging and Complex Deconvolution by Liu, Yunbo, Wear, Keith A., Harris, Gerald R.

“…Reliable acoustic characterization is fundamental for patient safety and clinical efficacy during high-intensity therapeutic ultrasound (HITU) treatment…”
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Estimation of fast and slow wave properties in cancellous bone using Prony's method and curve fitting by Wear, Keith A

“…The presence of two longitudinal waves in poroelastic media is predicted by Biot's theory and has been confirmed experimentally in through-transmission…”
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Improved measurement of acoustic output using complex deconvolution of hydrophone sensitivity by Wear, Keith, Gammell, Paul, Maruvada, Subha, Liu, Yunbo, Harris, Gerald

“…The traditional method for calculating acoustic pressure amplitude is to divide a hydrophone output voltage measurement by the hydrophone sensitivity at the…”
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Mechanisms of Interaction of Ultrasound With Cancellous Bone: A Review by Wear, Keith A.

“…Ultrasound is now a clinically accepted modality in the management of osteoporosis. The most common commercial clinical devices assess fracture risk from…”
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Decomposition of Two-Component Ultrasound Pulses in Cancellous Bone Using Modified Least Squares Prony Method – Phantom Experiment and Simulation by Wear, Keith A

“…Abstract Porous media such as cancellous bone often support the simultaneous propagation of two compressional waves. When small bone samples are interrogated…”
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Photoacoustic imaging phantoms for assessment of object detectability and boundary buildup artifacts by Palma-Chavez, Jorge, Wear, Keith A., Mantri, Yash, Jokerst, Jesse V., Vogt, William C.

“…Standardized phantoms and test methods are needed to accelerate clinical translation of emerging photoacoustic imaging (PAI) devices. Evaluating object…”
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Polyacrylamide hydrogel phantoms for performance evaluation of multispectral photoacoustic imaging systems by Hariri, Ali, Palma-Chavez, Jorge, Wear, Keith A., Pfefer, T. Joshua, Jokerst, Jesse V., Vogt, William C.

“…As photoacoustic imaging (PAI) begins to mature and undergo clinical translation, there is a need for well-validated, standardized performance test methods to…”
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Evaluation of Fluence Correction Algorithms in Multispectral Photoacoustic Imaging by Zhou, Xuewen, Akhlaghi, Nima, Wear, Keith A., Garra, Brian S., Pfefer, T. Joshua, Vogt, William C.

“…Multispectral photoacoustic imaging (MPAI) is a promising emerging diagnostic technology, but fluence artifacts can degrade device performance. Our goal was to…”
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Hydrophone Spatial Averaging Correction for Acoustic Exposure Measurements From Arrays-Part I: Theory and Impact on Diagnostic Safety Indexes by Wear, Keith A.

“…This article reports underestimation of mechanical index (MI) and nonscanned thermal index for bone near focus (TIB) due to hydrophone spatial averaging…”
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Spatiotemporal Deconvolution of Hydrophone Response for Linear and Nonlinear Beams-Part I: Theory, Spatial-Averaging Correction Formulas, and Criteria for Sensitive Element Size by Wear, Keith A.

“…This article reports spatiotemporal deconvolution methods and simple empirical formulas to correct pressure and beamwidth measurements for spatial averaging…”
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Considerations for Choosing Sensitive Element Size for Needle and Fiber-Optic Hydrophones-Part I: Spatiotemporal Transfer Function and Graphical Guide by Wear, Keith A.

“…The spatiotemporal transfer function for a needle or reflectance-based fiber-optic hydrophone is modeled as separable into the product of two filters…”
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Conventional, Bayesian, and Modified Prony's methods for characterizing fast and slow waves in equine cancellous bone by Groopman, Amber M, Katz, Jonathan I, Holland, Mark R, Fujita, Fuminori, Matsukawa, Mami, Mizuno, Katsunori, Wear, Keith A, Miller, James G

“…Conventional, Bayesian, and the modified least-squares Prony's plus curve-fitting (MLSP + CF) methods were applied to data acquired using 1 MHz center…”
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Nominal Versus Actual Spatial Resolution: Comparison of Directivity and Frequency-Dependent Effective Sensitive Element Size for Membrane, Needle, Capsule, and Fiber-Optic Hydrophones by Wear, Keith A., Shah, Anant

“…Frequency-dependent effective sensitive element radius <inline-formula> <tex-math notation="LaTeX">\boldsymbol{a}_{\text {eff}}{({f})}…”
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The dependencies of phase velocity and dispersion on trabecular thickness and spacing in trabecular bone-mimicking phantoms by WEAR, Keith A

“…Frequency-dependent phase velocity was measured in trabecular-bone-mimicking phantoms consisting of two-dimensional arrays of parallel nylon wires (simulating…”
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Directivity and Frequency-Dependent Effective Sensitive Element Size of Needle Hydrophones: Predictions From Four Theoretical Forms Compared With Measurements by Wear, Keith A., Baker, Christian, Miloro, Piero

“…Directivity is a hydrophone specification that describes response as a function of angle of incidence. The goal of this study was to compare, in the context of…”
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Interference between wave modes may contribute to the apparent negative dispersion observed in cancellous bone by ANDERSON, Christian C, MARUTYAN, Karen R, HOLLAND, Mark R, WEAR, Keith A, MILLER, James G

“…Previous work has shown that ultrasonic waves propagating through cancellous bone often exhibit a linear-with-frequency attenuation coefficient, but a decrease…”
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Spatiotemporal Deconvolution of Hydrophone Response for Linear and Nonlinear Beams-Part II: Experimental Validation by Wear, Keith A., Shah, Anant, Baker, Christian

“…This article reports experimental validation for spatiotemporal deconvolution methods and simple empirical formulas to correct pressure and beamwidth…”
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Directivity and Frequency-Dependent Effective Sensitive Element Size of Membrane Hydrophones: Theory Versus Experiment by Wear, Keith A., Baker, Christian, Miloro, Piero

“…It is important to know hydrophone frequency-dependent effective sensitive element size in order to account for spatial averaging artifacts in acoustic output…”
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Measurements of Ultrasonic Backscattered Spectral Centroid Shift From Spine In Vivo : Methodology and Preliminary Results by Garra, Brian S, Locher, Melanie, Felker, Steven, Wear, Keith A

“…Abstract Ultrasonic backscatter measurements from vertebral bodies (L3 and L4) in nine women were performed using a clinical ultrasonic imaging system…”
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