Bibliographies thématiques / Pulsed Ultrasound Velocimetry (PUV)

Littérature scientifique sur le sujet « Pulsed Ultrasound Velocimetry (PUV) »

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Publié le 10 mars 2023

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Articles de revues sur le sujet "Pulsed Ultrasound Velocimetry (PUV)"

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K, Anusha, Sadasiva Rao K, Srinivas M, Sreenu M et Aswani Kumar K. « Doppler Velocimetry of Uterine Artery in Bitches with Cystic Endometrial Hyperplasia-Pyometra Complex ». Indian Journal of Veterinary Sciences & ; Biotechnology 18, no 5 (7 novembre 2022) : 51–55. http://dx.doi.org/10.48165/ijvsbt.18.5.10.

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Doppler ultrasound is a useful diagnostic tool to evaluate uterine blood flow in different canine reproductive states. The aim of this study was to describe and compare uterine blood flow in bitches suffering from pyometra according to the ultrasonographic appearance of uterus. Seventy-five bitches with pyometra confirmed clinically, haematologically and ultrasonographically were included in the study. Ten healthy bitches with no haematological and ultrasonographic abnormality of uterus were also included in the study as control group. The bitches with pyometra were divided into four groups based on the sonographic characterization of uterus and its luminal contents, viz., B (few small cysts, normal endometrial surface, anechoic uterine content, n=11), C (many large cysts, irregular surface and hypertrophic endometrium, n=24), DH (many large cysts, irregular surface and hypertrophic endometrium, hyperechoic content, n=31) and DA (many large cysts, irregular surface and atrophic endometrium, hyperechoic content, n=9). The uterine horn diameter and uterine wall thickness was measured with two-dimensional ultrasonography. With the use of pulsed-wave Doppler, flow velocity waveforms of uterine artery were obtained. Parameters of blood flow velocity such as peak systolic velocity (PSV), end diastolic velocity (EDV), as well as haemodynamic parameters such as resistance index (RI), pulsatility index (PI) and systolic-diastolic ratio (S/D) were calculated electronically. Peak systolic velocity and end diastolic velocity were significantly higher in pyometra group than control with highest velocities recorded in DA group (P<0.05). The RI, PI and S/D were significantly lower in pyometra group than in control (P<0.05). The RI was significantly lower in group C and DA compared to groups B and DH (P<0.05). However, no significant difference was reported in PI and S/D among the groups of pyometra (P>0.05). It was concluded that the uterine artery blood flow velocity of bitches suffering from pyometra differs, not only from normal bitches, but also varies with the type of pyometra with varying pathological nature. Furthermore, haemodynamic parameters appear as useful markers to differentiate uterine pathologic conditions and to understand the pathological type of pyometra.
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Lin, Wei-Cheng, Ruei-Wen Ou, Hsiao-Chuan Liu et Jian-Xing Wu. « Particle image velocimetry for estimating shear wave elasticity imaging (SWEI) in the esophagus dysplasia ». Journal of the Acoustical Society of America 152, no 4 (octobre 2022) : A76. http://dx.doi.org/10.1121/10.0015599.

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In this study, a 128-channel high-frequency pulse generator/receiver system was used to emit multi-angle wave propagation, and the generator plane excitation was used to generate a focused beam, which induced the phenomenon of particle displacement in the esophagus phantom recorded. Shear wave electrography is generated by using a micro-ultrasound probe (ARFI), which excites the shear waves with the output acoustic energy. In addition, we perform the method of PIV proper orthogonal decomposition to better qualify and quantify the differences between the PIV and Doppler, especially for analysis block into PIV for particle tracking, in which the external environment, with a Doppler similarity index of 82%, and PIV mainly uses the Doppler algorithm for analysis and obtains 97 frames, and fixed 0.33 ms time difference to output pictures. Each pass interrogation area is set to 128 in sequence, the distance is defined in calibration, in which the low filter contrast of image-based validation is set to 0.004, and the bright filter objects are set to 0.5. Through the analysis results of PIV, each particle's speed and movement are critical for the hospital to think. The relative position of the lesion and the effect of ARFI on the lesion are to be understood by understanding the direction of movement of the contrast agent. Overall, the shear wave and Doppler output amplitudes provided the best image quality and PIV results for esophagus dysplasia.
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Blair, William F., Thomas D. Brown et E. R. Greene. « Pulsed ultrasound doppler velocimetry in the assessment of microvascular hemodynamics ». Journal of Orthopaedic Research 6, no 2 (mars 1988) : 300–309. http://dx.doi.org/10.1002/jor.1100060219.

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Schovanec, Petr, Darina Jasikova, Michal Kotek, Karel Havlicek, Magda Nechanicka, Jakub Eichler, Jiri Cech et Petra Subrtova. « Sterilization of Biofilm in Foam Using a Single Cavitation Bubble ». MATEC Web of Conferences 328 (2020) : 05003. http://dx.doi.org/10.1051/matecconf/202032805003.

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This article presents the sterilization of bacteria using cavitation bubbles. Cavitation generated by ultrasound creates a cavitation cloud. Therefore is more advantageous to generate the cavitation bubbles by laser-induced breakdown, because it is possible to generate individual bubbles for the purpose of study single impact and physical mechanism of acting. The cavitation bubble is generated by a Nd: YAG 532nm laser beam, a short 10ns pulse. Here, we used optics to focus the laser beam and a high-speed camera to visualize characteristics the bubble. We used the method of long-distance microscopy and shadowgraph lightening for the visualization. We used the particle image velocimetry (PIV) method to determine the interaction of the bubble with the surrounding liquid and solid surface. The main goal of the research is to use cavitation to sterilize bacteria and biofilm in impact of single bubble collapse on living cells.
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Grayburn, Paul A., John E. Willard, Donald R. Haagen, M. Elizabeth Brickner, Luis Alvarez et Eric J. Eichhorn. « Measurement of coronary flow using high-frequency intravascular ultrasound imaging and pulsed doppler velocimetry ». Journal of the American College of Cardiology 17, no 2 (février 1991) : A234. http://dx.doi.org/10.1016/0735-1097(91)91901-p.

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Eichhorn, Eric J., Luis G. Alvarez, Michael E. Jessen, Steven M. Fass, Robert Y. Chao, Donald Haagen et Paul A. Grayburn. « Measurement of coronary and peripheral artery flow by intravascular ultrasound and pulsed Doppler velocimetry ». American Journal of Cardiology 70, no 4 (août 1992) : 542–45. http://dx.doi.org/10.1016/0002-9149(92)91208-l.

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Brown, T. D., L. D. Bell, D. R. Pedersen et W. F. Blair. « A Three-Dimensional Computational Simulation of Some Sources of Measurement Artifact in Microvascular Pulsed Ultrasound Doppler Velocimetry ». Journal of Biomechanical Engineering 107, no 3 (1 août 1985) : 274–80. http://dx.doi.org/10.1115/1.3138553.

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Recent applications of 20 MHz pulsed ultrasound Doppler velocimetry (PUDVM) in microsurgical research have necessarily employed piezoelectric crystals whose diameter is not negligible compared to the lumen size (1–2 mm) of many vessels of interest. A three-dimensional numerical model was developed to explore relationships between actual and detected flow field parameters, for (steady) Poiseuille flow, when appreciable velocity gradients exist within the PUDVM sample volume. Validation studies showed that highly accurate velocity profiles could be obtained in the limiting case of a very small sample volume (0.1 mm radius), but that for currently employed crystals ( ≈ 0.5 mm radius) there was appreciable underestimation of the centersteam velocity, and appreciable overestimation of the flow stream diameter. Errors in perceived velocity and flow rate were found to be relatively insensitive to perturbations in the sample volume thickness, in the size of the sampling range increment, or in the angle of insonation beam divergence. By contrast, these apparent flow parameters were found to be very sensitive to perturbations of sample volume diameter or of the Dopper angle. Small variations in the degree of partial sample volume overlap of the flowstream periphery were shown to be capable of causing large fluctuations in apparent flow stream diameter.
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Messer, Matthias, et Cyrus K. Aidun. « Main effects on the accuracy of Pulsed-Ultrasound-Doppler-Velocimetry in the presence of rigid impermeable walls ». Flow Measurement and Instrumentation 20, no 2 (avril 2009) : 85–94. http://dx.doi.org/10.1016/j.flowmeasinst.2008.11.002.

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Grayburn, Paul A., John E. Willard, Donald R. Haagen, M. Elizabeth Brickner, Luis G. Alvarez et Eric J. Eichhorn. « Measurement of Coronary Flow Using High-Frequency Intravascular Ultrasound Imaging and Pulsed Doppler Velocimetry : In Vitro Feasibility Studies ». Journal of the American Society of Echocardiography 5, no 1 (janvier 1992) : 5–12. http://dx.doi.org/10.1016/s0894-7317(14)80098-9.

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Kasparek, Milos, Ludmila Novakova et Jan Malik. « Effect of Roller Pump Pulse in the Arterial Needle Area during Hemodialysis ». Diagnostics 11, no 11 (29 octobre 2021) : 2010. http://dx.doi.org/10.3390/diagnostics11112010.

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Vascular access is a lifeline for hemodialysis patients. Its lifetime is affected by many hemodynamic factors such as pressure, flow regime and wall shear stress. During hemodialysis, changes in hemodynamic parameters occur due to the flow from needles inserted into the vascular system. Primarily, there is a change in shear stress that affects the vascular wall. Pathological effects of high or low WSS are known. The effect of jet from a venous needle on hemodynamics parameters was studied, but the influence of the arterial needle on hemodynamics parameters is not sufficiently studied. To understand its possible effects, we performed in vivo and in vitro studies. Methods. In vivo experiment: The existence of flow reversal around the suction needle was visualized in a group of 12 randomly selected patients using ultrasound velocity profiling (Doppler ultrasonography) during hemodialysis. In vitro experiment: The flow field was measured using the stereo particle image velocimetry method (stereo PIV). Two regimes were studied. In the first regime, the fluid in the extracorporeal circuit was pumped by a peristaltic pump. In the second regime, the continuous pump was used in the extracorporeal circuit. The conditions were set to resemble those in vascular access during a hemodialysis session. Flow volume was set to 600 mL/min for vascular access and 200 mL/min for the extracorporeal circuit. Results. The main finding of this study was that the wall in the region of the arterial needle was stressed by backflow through the arterial needle. Since this was a variable, low-shear stress loading, it was one of the risk factors for the development of stenosis. Cyclic flow reversal was apparent in all of the included hemodialysis patients. The stereo PIV in vitro experiment revealed the oscillating character of wall shear stress (WSS) inside the model. High shear stress was documented upstream of the injection point of the arterial needle. An area of very low WSS was detected right behind the injection point during a pulse of the peristaltic pump. The minimal and maximal values of the WSS during a pulse of the peristaltic pump in the observed area were −0.7 Pa and 6 Pa, respectively. The distribution of wall shear stress with the continual pump used in the extracorporeal circuit was similar to the distribution during a pulse of the peristaltic one. However, the WSS values were continual; the WSS did not oscillate. WSS ranged between 4.8 Pa and 1.0 Pa.
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Thèses sur le sujet "Pulsed Ultrasound Velocimetry (PUV)"

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Kotze, Reinhardt. « Detailed non-Newtonian flow behaviour measurements using a pulsed ultrasound velocimetry method : Evaluation, optimisation and application ». Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/2183.

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Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2011
Ultrasonic Velocity Profiling (UVP) is both a method and a device to measure an instantaneous one-dimensional velocity profile along a measurement axis by using Doppler echography. UVP is an ideal technique since it is non-invasive, works with opaque systems, inexpensive, portable and easy to implement relative to other velocity profile measurement methods. Studies have suggested that the accuracy of the measured velocity gradient close to wall interfaces need to be improved. The reason for this is due to, depending on the installation method, distortion caused by cavities situated in front of ultrasonic transducers, measurement volumes overlapping wall interfaces, refraction of the ultrasonic wave as well as sound velocity variations. A new ultrasonic transducer, which incorporates a delay line material optimised for beam forming could reduce these problems (Wiklund, 2007). If these could be addressed, UVP could be used for the measurement of velocity profiles in complex geometries (e.g. contractions, valves, bends and other pipe fittings) where the shape of the velocity profile is critical to derive models for estimating fluid momentum and kinetic energy for energy efficient designs. The objective of this research work was to optimise the UVP system for accurate complex flow measurements by evaluating a specially designed delay line transducer and implementing advanced signal processing techniques. The experimental work was conducted at the Material Science and Technology (MST) group at the Cape Peninsula University of Technology (CPUT). This work also formed part of a collaborative project with SIK - The Swedish Institute for Food and Biotechnology. Acoustic characterisation of the ultrasonic transducers using an advanced robotic setup was done at SI K. Different concentrations of the following non-Newtonian fluids exhibiting different rheological characteristics were used for testing: carboxymethyl cellulose (CMC) solutions, kaolin and bentonite suspensions. Water was used for calibration purposes.
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Messer, Matthias. « Pulsed ultrasonic doppler velocimetry for measurement of velocity profiles in small channels and capplilaries ». Thesis, Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-09022005-131744/.

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Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2006.
Cyrus K. Aidun, Committee Member ; Farrokh Mistree, Committee Member ; Yves H. Berthelot, Committee Member ; Philip J. W. Roberts, Committee Member. Includes bibliographical references.
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Shamu, Tafadzwa John. « Evaluation and characterisation of an ultrasound based in-line rheometric system for industrial fluids ». Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2189.

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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology.
Pulsed Ultrasound Velocimetry combined with Pressure Difference (PUV+PD) measurement is a non-invasive in-line rheometric technique which is used to analyse the complex flow properties of industrial fluids for quality control purposes. Cape Peninsula University of Technology (CPUT) and Technical Research Institute of Sweden (SP) have developed and patented a new PUV+PD based system, called Flow-Viz™. Despite this advancement, the system and ultrasound sensor technology have not been fully tested and evaluated in a wide range of industrial fluids. Acoustic characterisation tests were carried out at SP, with the aim of understanding the ultrasound beam properties after propagating through industrial stainless steel (316L) pipe walls. For these tests, a high-precision robotic XYZ-scanner and needle hydrophone setup were used. Different ultrasound sensor configurations were mounted to a stainless steel pipe while using different coupling media between the transducer-to-wedge and sensor wedge-to-pipe boundaries. The ultrasound beam propagation after the wall interface was measured by navigating the needle hydrophone within a predefined 2-dimensional spatial grid. The most suitable coupling material was determined from the acoustic characterisation, and then used in the in-line rheological characterisation tests to evaluate the performance of the Flow-VizTM rheometric unit against conventional tube viscometry. The in-line rheological tests were conducted with bentonite, kaolin and Carboxymethyl cellulose (CMC) model fluids. The flow loop used consisted of three different pipe test sections; and two concentrations of each fluid were tested in order to ascertain the consistency of the measurements. The in-line rheological tests showed good agreement (±15%) between the two techniques and Flow-VizTM was able to provide important data at very low shear rates. Acoustic characterisation indicated that variations in the beam properties were highly dependent on the acoustic couplants used to mount the sensors to the stainless steel pipes. Furthermore, the in-line results showed the effectiveness of Flow-VizTM as an industrial rheometer. The non-invasive ultrasound sensor technology, was for the first time acoustically characterised through stainless steel. This information will now be used to further optimise the unique technology for advanced industrial applications, e.g. oil drilling fields, complex cement grout and food processing applications.
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MEACCI, VALENTINO. « Novel Ultrasound Imaging Techniques ». Doctoral thesis, 2017. http://hdl.handle.net/2158/1076931.

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Ultrasound Imaging is widely used in biomedical and industrial applications, due to its non-invasive, non-destructive and non-ionizing nature. In the last 20 years, Ultrasound imaging has been continuously growing in both of these fields, since it has benefited from advances in electronic technologies and in signal processing methods. For industrial applications, a wide variety of instruments, based on ultrasound, have been designed to measure the properties and composition of materials and products. In particular, monitoring all of the steps of a production chain is crucial for process optimization and product quality in industries. In the medical area, ultrasound systems are widely used to investigate the tissue, by 2D morphological imaging, and the blood movement, by Doppler analysis. The large use of ultrasound equipment has further increased the research and the development activity of new investigation methods. Consequently, “open” systems capable of satisfying the research needs are in great demand. The activity of this PhD was focused on the design of new electronic architectures and systems capable of addressing some of the emerging needs in medical and industrial fields. In several industrial fields the products are checked by taking samples from the production chain, which are lately analyzed in specialized laboratories by using manual, expensive and time consuming operations. Systems capable of in-line and on-site monitoring products and materials would be of high value. For these reasons, we developed an ultrasound system for monitoring the properties of the fluids or suspensions flowing in pipes and another system to assess the concrete strength during the hydration process. The first one is a system with a wide range of applications, since a lot of products as food, medicines and cosmetics are in a fluid or suspension state during the production. It is a pulse wave system that measures the velocity profile of the fluids flowing in a pipe and uses the relation between the velocity profile and the fluid rheological properties to evaluate the quality of the products and keep the production chain under control. The second system evaluates the concrete strength, a parameter of paramount importance to guarantee durable and safe constructions. It is a pulse wave system that exploits a reflectometry technique to monitor the concrete strength evolution during the hardening process by analyzing the reflected signal at interface concrete-Plexiglas. In medical applications, High Frame Rate (HFR) imaging methods based on the transmission of defocused, plane-wave (PW) or multi-focused beams rather than single-focused beams, are increasingly popular. These methods lead to unprecedented performance that enables the reconstruction of 2D vector maps of the blood velocity distribution, or 3D investigations with improved resolution, but they are unfortunately very demanding in term of processing power. Therefore, the design and development of novel HFR methods and systems capable to efficiently implement the HFR imaging methods, is a crucial challenge. Toward this goal the Micro Systems Design Laboratory (MSD Lab) of the University of Florence developed a novel research scanner called ULtrasound Advanced Open Platform 256 (ULA-OP 256). ULA-OP 256 can independently manage up to 256 transmit/receive (TX-RX) channels. It has high computational power in a small size, compatible with mobility. The system supports a wide range of transmission/receiving strategies, processes data in real time, stores data for post-processing, and can be connected to matrix probes. In particular, the platform implements an advanced beamformer architecture, named Multi-Line Parallel Beamformer (MLPBF). MLPBF exploits a combination of parallel and serial processing strategies that make HFR imaging possible.
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Actes de conférences sur le sujet "Pulsed Ultrasound Velocimetry (PUV)"

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Peronneau, Pierre. « Ultrasound pulsed Doppler velocimetry ». Dans 1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 1992. http://dx.doi.org/10.1109/iembs.1992.5761728.

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Peronneau. « Ultrasound Pulsed Doppler Velocimetry ». Dans Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 1992. http://dx.doi.org/10.1109/iembs.1992.593832.

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Furlan, John M., Mohamed Garman, Jaikrishnan Kadambi, Robert J. Visintainer et Krishnan V. Pagalthivarthi. « Ultrasonic Measurements of Local Particle Velocity and Concentration Within the Casing of a Centrifugal Pump ». Dans ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-31217.

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In the design of slurry transport equipment used in the mining and dredging industries, the effects of solid particle velocity and concentration on hydraulic performance and wear need to be considered. Two ultrasonic techniques have been used to investigate slurry flows through a centrifugal pump casing: a local particle concentration measurement technique (Furlan et al., 2012) and a pulsed ultrasonic Doppler Velocimetry (PUDV) technique (Hanjiang, 2003, Garman, 2015). Local particle velocities and concentrations have been obtained in a flow of soda lime glass particles (diameter of 195 μm) and water through the casing of a centrifugal slurry pump operating close to the best efficiency point using the two ultrasound techniques. For the concentration measurements, the acoustic properties of slurry flows such as sonic velocity, backscatter, and attenuation are correlated to the volume fraction of solid particles. The algorithm utilizes measurements obtained from homogeneous vertical pipe flow fields as calibration data in order to obtain experimental concentration profiles in the non-homogenous flow regimes which are encountered in the pump casing. The PUDV technique correlates the Doppler shift in frequency associated with the movement of particles towards or away from the transducer. A two measurement (angle) technique is applied within the pump casing in order to account for the components of particle velocity which are orthogonal to the casing side wall. The techniques are utilized to obtain concentration and velocity profiles within the pump casing for overall average loop particle concentrations ranging from 7–11 % by volume. The experimental results are compared with the concentration and velocity fields that are predicted by in-house finite element computational fluid dynamics (CFD) codes (Pagalthivarthi and Visintainer, 2009) which are used to predict wear in centrifugal slurry pump wet end components. Reasonable agreement is observed for both the concentration and velocity fields. Specifically, measurements indicate that there is a reduction of in-situ concentration and hence a corresponding radial acceleration of the particles with respect to the fluid occurring within the impeller which has also been predicted by computational predictions of flow through the impeller (Pagalthivarthi et al., 2013). Additionally, the prediction of the existence of secondary flow patterns by the casing computational code has been supported with the velocity measurements.
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Koutsouridis, G. G., N. Bijnens, P. J. Brands, F. N. van de Vosse et M. C. M. Rutten. « In-Vivo Real-Time Contrast-Free Ultrasonic Blood Flow Velocity Profile Measurement ». Dans ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80542.

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Recently, Ultrasonic Perpendicular Velocimetry (UPV) based algorithms, as opposed to commonly used Doppler technique (Figure 1), were applied to Radio Frequency (RF)-data acquired in an in-vitro setup [1,3]. Thus, the estimation of velocity components perpendicularly to the ultrasound beam and the simultaneous and accurate assessment of wall position and axial velocity profiles were made feasible. By integrating the measured velocity profile an accurate flow estimation was made possible. Furthermore, the ratio between the changes in flow Q(t) and the changes in cross-sectional area of the vessel A(t) was found to offer an accurate estimation of the local Pulse Wave Velocity (PWV). By combining the PWV with the diameter waveform, accurate local pressure estimation was obtained indicating that a non-invasive pressure assessment by means of ultrasound is feasible [3]. However, the abovementioned method is time consuming due to the data size and the post-processing procedure required. Additionally, the Fast Fourier Transform (FFT) on Butterworth Band Pass Filters (BPF) for vessel’s wall removal requires contrast agents dispersion in the fluid for the application of UPV. A real-time approach, of the previously described techniques, was applied [2] in-vitro using a Blood Mimicking Fluid (BMF), as contrast agent, resembling the rheological (shear thinning) and acoustical (backscattering) properties of blood and ex-vivo using BMF or contrast-free real blood implementing Wavelet Transform (WT) filtering. The use of a Graphics Processing Unit (GPU) [4], succeeded in considerable acceleration and WT [5] filtering on the rough RF-data, in improvement of the discrimination between reflections from the vessel wall and scattering from small particles. In this research the method is extended to include in-vivo measurements.
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