journal
MENU ▼
Read by QxMD icon Read
search

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control

journal
https://www.readbyqxmd.com/read/28436860/effect-on-high-intensity-fields-of-a-tough-hydrophone-with-hydrothermal-pzt-thick-film-vibrator-and-titanium-front-layer
#1
Nagaya Okada, Shinichi Takeuchi
A novel tough hydrophone was fabricated by depositing hydrothermally synthesized lead zirconate titanate polycrystalline film on the back-side surface of a titanium plate. Our developed tough hydrophone resisted damage in a high-pressure field (15 MPa) at a focal point of a sinusoidal continuous wave driven by a concave high-intensity focused ultrasound (HIFU) transducer with up to 50 W of power input to the sound source. The hydrophone was suitable for the HIFU field, even though the hydrophone has a flat-shape tip of 3...
April 24, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28436859/in-vivo-intracardiac-vector-velocity-imaging-using-phased-array-transducers-for-pediatric-cardiology
#2
Solveig Fadnes, Morten Wigen, Siri Ann Nyrnes, Lasse Lovstakken
Two-dimensional blood speckle tracking has shown promise for measuring complex flow patterns in neonatal hearts using linear arrays and high-frame-rate plane wave imaging. For general pediatric applications, however, the need for phased array probes emerges due to the limited intercostal acoustic window available. In this work, a clinically approved real-time duplex imaging setup with phased array probes was used to investigate the potential of blood speckle tracking for 2-D vector velocity imaging of children with congenital heart disease...
April 24, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28422658/equivalent-magnetic-noise-in-magnetoelectric-laminates-comprising-bidomain-linbo-sub-3-sub-crystals
#3
Joao Vidal, Andrey V Turutin, Ilya V Kubasov, Mikhail D Malinkovich, Yurii N Parkhomenko, Svetlana P Kobeleva, Andrei L Kholkin, Nikolai A Sobolev
The anisotropic direct magnetoelectric (ME) properties of bi-layered composites comprising magnetostrictive metglas foils and single-crystalline piezoelectric bidomain plates of 127ºY-cut LiNbO<sub>3<sub> (LNO) have been studied theoretically and experimentally. The LNO plates possessed an engineered ferroelectric macrobidomain structure with opposite spontaneous polarization vectors. Impedance, ME effect and equivalent magnetic noise density measurements have been performed under quasi-static and resonant conditions...
April 13, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28422657/phased-array-ultrasound-system-for-planar-flow-mapping-in-liquid-metals
#4
Kevin Mader, Richard Nauber, Vladimir Galindo, Hannes Beyer, Lars Buttner, Sven Eckert, Jurgen Czarske
Controllable magnetic fields can be used to optimize flows in technical and industrial processes involving liquid metals in order to improve quality and yield. However, experimental studies in magnetohydrodynamics (MHD) often involve complex, turbulent flows and require planar, two-component velocity measurements through only one acoustical access. We present the phased array ultrasound Doppler velocimeter (PAUDV) as a modular research platform for flow mapping in liquid metals. It combines the pulse wave Doppler method with the phased array technique to adaptively focus the ultrasound beam...
April 12, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28422656/fast-plane-wave-2-d-vector-flow-imaging-using-transverse-oscillation-and-directional-beamforming
#5
Jonas Jensen, Carlos A Villagomez-Hoyos, Matthias B Stuart, Caroline Ewertsen, Michael R Nielsen, Jorgen Jensen
Several techniques can estimate the 2-D velocity vector in ultrasound. Directional beamforming (DB) estimates blood flow velocities with a higher precision and accuracy than transverse oscillation (TO), but at the cost of a high beamforming load when estimating the flow angle. In this paper, it is proposed to use TO to estimate an initial flow angle, which is then refined in a DB step. Velocity magnitude is estimated along the flow direction using cross-correlation. It is shown that the suggested TO-DB method can improve the performance of velocity estimates compared to TO, and with a beamforming load, which is 4...
April 12, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28410103/the-ultrasound-needle-pulse
#6
Kevin Parker, Shujie Chen, Miguel Alonso
Recent theoretical developments have defined the conditions for forming a broadband beam that is narrow in axial extent but extended in range. The formulation is based on the classical Angular Spectrum decomposition and the requirement for arranging all spatial and temporal frequencies such that all components have constant phase propagation between planes. Analytic formulations are given for a one dimensional source and a 2D axisymmetric source, and comparisons are made against conventional focused Gaussian beams under similar conditions relevant to medical imaging systems...
April 7, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28410102/scanned-three-dimensional-intracardiac-arfi-and-swei-for-imaging-radiofrequency-ablation-lesions
#7
Peter Hollender, Lily Kuo, Virginia Chen, Stephanie Eyerly, Patrick Wolf, Gregg Trahey
Radiofrequency ablation (RFA) is used to locally disrupt electrical propagation in myocardium and treat arrhythmias, and direct visualization of ablation lesions by acoustic radiation force methods may benefit RFA procedures. This work compares four imaging modalities, B-Mode, ARFI, STL-SWEI and MTL-SWEI, in their ability to resolve RFA lesions in four ex vivo experiments. Ablation lesions are shown to be marked by at least a local halving of ARFI displacements and doubling of shear wave speeds. In a controlled ablation of ex vivo porcine and canine cardiac tissue, STL-SWEI and ARFI are shown to have similar CNR, better than MTL-SWEI and B-Mode...
April 7, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28391195/development-of-a-low-complexity-cost-effective-digital-beamformer-architecture-for-high-frequency-ultrasound-imaging
#8
Changhan Yoon, Hyung Ham Kim, K K Shung
This paper presents a low-complexity, cost-effective digital beamformer architecture for a high-frequency ultrasound imaging system. The proposed beamformer uses a look-up-table (LUT) and linear interpolation methods for computing the dynamic receive focusing delays and a post-filtering technique to minimize hardware complexity. In the post-filtering technique, channel radio-frequency (RF) data having the same fractional delay (i.e., 16f0 resolution) are aggregated prior to interpolation. Thus, only four polyphase structure filters are required in the developed beamformer...
April 4, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28391194/acoustic-wave-filter-technology-a-review
#9
Clemens Ruppel
Today, acoustic filters are the filter technology to meet the requirements with respect to performance dictated by the cellular phone standards and their form factor. Around 2 billion cellular phones are sold every year, and smart phones are of a very high percentage of approximately two thirds. Smart phones require a very high number of filter functions ranging from the low double-digit range up to almost triple digit numbers in the near future. In the frequency range up to 1 GHz surface acoustic wave (SAW) filters are almost exclusively employed, while in the higher frequency range bulk acoustic wave (BAW) and SAW filters are competing for their shares...
April 4, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28391193/ultrasonic-imaging-in-highly-attenuating-materials-with-hadamard-codes-and-the-decomposition-of-the-time-reversal-operator
#10
Eduardo Lopez Villaverde, Sebastien Robert, Claire Prada
In this work, defects in a high density polyethylene pipe are imaged with the total focusing method. The viscoelastic attenuation of this material greatly reduces the signal level and leads to a poor signal-to-noise ratio due to electronic noise. To improve the image quality, the decomposition of the time reversal operator method is combined with the spatial Hadamard coded transmissions before calculating images in the time domain. Because the Hadamard coding is not compatible with conventional imaging systems, the paper proposes two modified coding methods based on sparse Hadamard matrices with +1/0 coefficients...
April 3, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28371775/acoustic-radiation-force-impulse-arfi-induced-peak-displacements-reflect-degree-of-anisotropy-in-transversely-isotropic-elastic-materials
#11
Md Murad Hossain, Christopher Moore, Caterina Gallippi
In transversely isotropic (TI) materials, mechanical properties (Young's modulus, shear modulus, and Poisson's ratio) are different along versus across the axis of symmetry (AoS). In this work, the feasibility of interrogating such directional mechanical property differences using acoustic radiation force impulse (ARFI) imaging is investigated. We herein test the hypotheses that 1) ARFI-induced peak displacements (PDs) vary with TI material orientations when an asymmetrical ARFI excitation point spread function (PSF) is used, but not when a symmetrical ARFI PSF is employed; and 2) the ratio of PDs induced with the long axis of an asymmetrical ARFI PSF oriented along versus across the material's AoS is related to the degree of anisotropy of the material...
March 31, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28358682/curvilinear-3-d-imaging-using-row-column-addressed-2-d-arrays-with-a-diverging-lens-feasibility-study
#12
Hamed Bouzari, Mathias Engholm, Christopher Beers, Matthias B Stuart, Svetoslav I Nikolov, Erik V Thomsen, Jorgen A Jensen
Constructing a double-curved row-columnaddressed (RCA) 2-D array or applying a diverging lens over the flat RCA 2-D array can extend the imaging field-of-view (FOV) to a curvilinear volume without increasing the aperture size, which is necessary for applications such as abdominal and cardiac imaging. Extended FOV and low channel count of double-curved RCA 2-D arrays make 3-D imaging possible with equipment in the price range of conventional 2-D imaging. This study proposes a delay-and-sum beamformation scheme specific to double-curved RCA 2-D arrays and validates its focusing ability based on simulations...
March 24, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28358681/fast-nonlinear-ultrasound-propagation-simulation-using-a-slowly-varying-envelope-approximation
#13
Francois Varray, Matthieu Toulemonde, Adeline Bernard, Olivier Basset, Christian Cachard
Medical systems usually consider linear propagation of ultrasound, an approximation of reality. However, numerous studies have attempted to accurately simulate the nonlinear pressure wave distortion and to evaluate the contribution of harmonic frequencies. In such simulations, the computation time is very large, except for the method based on the angular spectrum scheme where the derivative order is reduced using the Fourier transform. However, the harmonic computation is usually limited to the second harmonic because of quasi-linear approximation...
March 24, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28358679/ultrasound-pixel-based-beamforming-with-phase-alignments-of-focused-beams
#14
Nghia Q Nguyen, Richard Prager
We previously developed unified pixel-based beamforming to generate high-resolution sonograms, based on field pattern analysis. In this framework, we found the transmit wave-shape away from the focus could be characterized by two spherical pulses. These correspond to the maximal and minimal distances from the imaging point to the active aperture. The beamformer uses this model to select the highest-energy signals from backscattered data. A spatiotemporal interpolation formula is used to provide a smooth transition in regions near the focal depth where there is no dominant reflected pulse...
March 24, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28358680/fast-orthogonal-row-column-electronic-scanning-forces-with-top-orthogonal-to-bottom-electrode-tobe-arrays
#15
Christopher Ceroici, Tyler Harrison, Roger Zemp
Recently, Top-Orthogonal-to-Bottom Electrode (TOBE) 2D arrays were introduced as a practical design for 3D ultrasound imaging without requiring the wiring a 2D grid of elements. However, previously proposed imaging schemes suffered from speed or image quality limitations. Here we propose a new imaging scheme which we call Fast Orthogonal Row-Column Electronic Scanning (FORCES). This new approach takes advantage of bias-sensitivity to enable high-quality and fast B-scan imaging. We compare this imaging scheme with an equivalent linear array, a previously proposed row-column imaging scheme, as well as with the Explososcan imaging scheme for 2D arrays through simulations...
March 23, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28333626/temperature-dependence-of-domain-contributions-as-a-function-of-ageing-in-soft-and-hard-lead-zirconate-titanate-piezoelectric-ceramics
#16
Sayyed A Qaisar, Timothy P Comyn, Andrew J Bell
The stress and temperature dependence of three different PZT ceramics have been measured at 48 hours and 1 month after poling. The data were fitted to a modified Rayleigh law in which a negative quadratic stress term accounts for a saturation of the domain wall contributions at higher stress. The relative changes to the fitting parameters can be explained by the materials possessing differences in the concentration of orientable defect dipoles, but with similar distributions of relaxation time constants.
March 22, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28333625/real-time-nonlocal-means-based-despeckling
#17
Lars H Breivik, Sten Roar Snare, Erik N Steen, Anne H Solberg
In this paper we propose a multiscale nonlocal means based despeckling method for medical ultrasound. The multiscale approach leads to large computational savings and improves despeckling results over single scale iterative approaches. We present two variants of the method. The first, denoted multiscale nonlocal means, yields uniform robust filtering of speckle both in structured and homogeneous regions. The second, denoted unnormalized multiscale nonlocal means, is more conservative in regions of structure assuring minimal disruption of salient image details...
March 22, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28333624/a-fast-and-robust-beamspace-adaptive-beamformer-for-medical-ultrasound-imaging
#18
Ali Mohades Deylami, Babak Mohammadzadeh Asl
Minimum variance beamformer (MVB) increases the resolution and contrast of medical ultrasound imaging compared to non-adaptive beamformers. These advantages come at the expense of high computational complexity that prevents this adaptive beamformer to be applied in a real-time imaging system. A new beamspace based on discrete cosine transform (DCT) is proposed in which the medical ultrasound signals can be represented with less dimensions compared to the standard beamspace. This is because of symmetric beampattern of the beams in the proposed beamspace compared to the asymmetric ones in the standard beamspace...
March 21, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28328505/blocked-elements-in-1-d-and-2-d-arrays-part-ii-compensation-methods-as-applied-to-large-coherent-apertures
#19
Marko Jakovljevic, Nick Bottenus, Lily Kuo, Shalki Kumar, Jeremy J Dahl, Gregg E Trahey
In Part I of the paper, we detected elements blocked by ribs during simulated and in vivo transcostal liver scans, and we turned those elements off to compensate for the loss in visibility of liver vasculature. Here, we apply blocked-element detection and adaptive compensation to large synthetic aperture data collected through rib samples ex vivo, in order to reduce near-field clutter and to recover lateral resolution. To construct large synthetic transmit and receive apertures, we collected the individual channel signals from a fully-sampled matrix array at multiple and know array locations across the tissue samples...
March 16, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28328504/blocked-elements-in-1-d-and-2-d-arrays-part-i-detection-and-basic-compensation-on-simulated-and-i-in-vivo-i-targets
#20
Marko Jakovljevic, Gianmarco Pinton, Jeremy J Dahl, Gregg Trahey
During a transcostal ultrasound scan, ribs and other highly attenuating and/or reflective tissue structures can block parts of the array. Blocked elements tend to limit the acoustic window and impede visualization of structures of interest. Here, we demonstrate a method to detect blocked elements and we measure the loss of image quality they introduce in simulation and in vivo. We utilize a fullwave simulation tool and a clinical ultrasound scanner to obtain element signals from fullysampled matrix arrays during simulated and in vivo transcostal liver scans, respectively...
March 16, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
journal
journal
33912
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"