scholarly journals The Impact of Function-Flow Interaction on Left Ventricular Efficiency in Patients with Conduction Abnormalities: A Particle Image Velocimetry and Tissue Doppler Study

2016 ◽  
Vol 29 (5) ◽  
pp. 431-440 ◽  
Author(s):  
Emre Gürel ◽  
Christian Prinz ◽  
Lieve Van Casteren ◽  
Hang Gao ◽  
Rik Willems ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Tissue Doppler ◽  
Left Ventricular ◽  
Flow Interaction ◽  
Conduction Abnormalities ◽  
Doppler Study ◽  
Image Velocimetry ◽  
Ventricular Efficiency ◽  
The Impact

Particle image velocimetry study of the celiac trunk hemodynamic induced by continuous-flow left ventricular assist device

2017 ◽  
Vol 47 ◽  
pp. 47-54 ◽  
Author(s):  
Francesco Scardulla ◽  
Diego Bellavia ◽  
Leonardo D'Acquisto ◽  
Giuseppe M Raffa ◽  
Salvatore Pasta
Keyword(s):  
Particle Image Velocimetry ◽  
Continuous Flow ◽  
Particle Image ◽  
Celiac Trunk ◽  
Left Ventricular ◽  
Assist Device ◽  
Ventricular Assist ◽  
Image Velocimetry ◽  
Left Ventricular Assist ◽  
Particle Image Velocimetry Study

The impact of optical turbulence on particle image velocimetry

2017 ◽  
Author(s):  
Silvia Matt ◽  
Gero Nootz ◽  
Samuel Hellman ◽  
Weilin Hou
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Optical Turbulence ◽  
Image Velocimetry ◽  
The Impact

Abstract 13873: Quantitative Characteristics of Left Ventricular Vortex Flow in the Short and Long Axis Views by High Frame Rate Echocardiographic Particle Image Velocimetry

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Haruhiko Abe ◽  
Kasumi Masuda ◽  
Toshihiko Asanuma ◽  
Hikaru Koriyama ◽  
Yukihiro Koretsune ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Vortex Flow ◽  
Cardiac Cycle ◽  
Particle Image ◽  
Left Ventricular ◽  
Frame Rate ◽  
Vortex Strength ◽  
High Frame Rate ◽  
Image Velocimetry ◽  
Quantitative Characteristics

Background: Vortex flow in the left ventricle (LV) has three-dimensional structure and plays an important role in avoiding excessive dissipation of energy. However, quantitative characteristics of long and short axis (LAX and SAX) vortex flow have not been elucidated. Echocardiographic particle image velocimetry (Echo-PIV) is an emerging technique to evaluate instantaneous vortical flow inside the LV. However, it has a limitation of underestimation of high velocities due to limited frame rate. Moreover, previous investigations have mainly focused on vortex from LAX view. Therefore, we used high frame rate Echo-PIV to quantitate vortex flow in SAX as well as in LAX views to understand characteristics of vortex three-dimensionally. Methods: Echocardiographic contrast images of the LV SAX and LAX were acquired from 8 open-chest healthy dogs. The acquisition frame rate was 135 frames per second and the contrast bubbles density was optimized for blood flow analysis. Echo-PIV analysis was performed off-line by using commercially available software and vorticity data were calculated in the region of interest (ROI) throughout the cardiac cycle. ROI was manually placed on the vortex. Vortex strength was defined as the averaged vorticity within the ROI. Results: In SAX, counterclockwise vortex was seen near the anterior wall, and in LAX clockwise vortex was seen in the anterior mid-ventricle. Both in SAX and LAX views, vortex strength showed significant phasic variations being largest in isovolumic contraction (vortex strength, SAX 9.2±2.3/s, p<0.001; LAX -12.0±2.4/s, p<0.001), and smallest in isovolumic relaxation (SAX -0.8±0.8/s, p<0.001; LAX -1.9±1.9/s, p<0.001). Conclusion: High frame rate Echo-PIV successfully demonstrated a complicated pattern of intracardiac vortex with phasic variation of its strength throughout a cardiac cycle in both SAX and LAX. This method may be a useful tool to assess physiological role of vortex in the flow dynamics.

Study of the impact of aeration on the lubricant behavior in a tapered roller bearing: innovative numerical modelling and validation via particle image velocimetry

2021 ◽  
pp. 107301
Author(s):  
Lorenzo Maccioni ◽  
Valery G. Chernoray ◽  
Marco N. Mastrone ◽  
Christof Bohnert ◽  
Franco Concli
Keyword(s):  
Particle Image Velocimetry ◽  
Numerical Modelling ◽  
Particle Image ◽  
Roller Bearing ◽  
Tapered Roller Bearing ◽  
Image Velocimetry ◽  
Tapered Roller ◽  
The Impact

Analysis of left ventricular fluid dynamics in dilated cardiomyopathy by echocardiographic particle image velocimetry

2017 ◽  
Vol 35 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Chouchou Tang ◽  
Yizhong Zhu ◽  
Jing Zhang ◽  
Chengcheng Niu ◽  
Dan Liu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Particle Image Velocimetry ◽  
Dilated Cardiomyopathy ◽  
Particle Image ◽  
Left Ventricular ◽  
Image Velocimetry

scholarly journals Evaluation of patients with a HeartMate 3 left ventricular assist device using echocardiographic particle image velocimetry

2020 ◽  
Author(s):  
Arend F. L. Schinkel ◽  
Sakir Akin ◽  
Mihai Strachinaru ◽  
Rahatullah Muslem ◽  
Dan Bowen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Vortex Formation ◽  
Left Ventricular ◽  
Flow Dynamics ◽  
Lv Function ◽  
Image Velocimetry ◽  
Intraventricular Flow ◽  
Blood Flow Dynamics

Abstract Purpose Poor left ventricular (LV) function may affect the physiological intraventricular blood flow and physiological vortex formation. The aim of this study was to investigate the pattern of intraventricular blood flow dynamics in patients with LV assist devices (LVADs) using echocardiographic particle image velocimetry. Materials and methods This prospective study included 17 patients (mean age 57 ± 11 years, 82% male) who had received an LVAD (HeartMate 3, Abbott Laboratories, Chicago, Illinois, USA) because of end-stage heart failure and poor LV function. Eleven (64%) patients had ischemic cardiomyopathy, and six patients (36%) had nonischemic cardiomyopathy. All patients underwent echocardiography, including intravenous administration of an ultrasound-enhancing agent (SonoVue, Bracco, Milan, Italy). Echocardiographic particle image velocimetry was used to quantify LV blood flow dynamics, including vortex formation (Hyperflow software, Tomtec imaging systems Gmbh, Unterschleissheim, Germany). Results Contrast-enhanced ultrasound was well tolerated in all patients and was performed without adverse reactions or side effects. The LVAD function parameters did not change during or after the ultrasound examination. The LVAD flow was on average 4.3 ± 0.3 L/min, and the speed was 5247 ± 109 rotations/min. The quantification of LV intraventricular flow demonstrated substantial impairment of vortex parameters. The energy dissipation, vorticity, and kinetic energy fluctuation indices were severely impaired. Conclusions Echo particle velocimetry is safe and feasible for the quantitative assessment of intraventricular flow in patients with an LVAD. The intraventricular LV flow and vortex parameters are severely impaired in these patients.

Particle Image Velocimetry Measurement and Computational Fluid Dynamic Simulations of the Unsteady Flow Within a Rotating Disk Cavity

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Xiang Luo ◽  
Dongdong Liu ◽  
Hongwei Wu ◽  
Zhi Tao
Keyword(s):  
Particle Image Velocimetry ◽  
Computational Fluid Dynamic ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Rotating Disk ◽  
Turbine Rotor ◽  
Dynamic Simulations ◽  
Image Velocimetry ◽  
The Impact

In this article a combined experimental and numerical investigation of the unsteady mixing flow of the ingestion gas and rim sealing air inside a rotating disk cavity was carried out. A new test rig was set up, and the experiments were conducted on a 1.5-stage turbine rotor disk and included pressure measurements. The flow structure of the mixing region of the ingestion gas and sealing air in cavity was measured using the particle image velocimetry (PIV) technique. To complement the experimental investigation and to aid in understanding the flow mechanism within the cavity, a three-dimensional (3D) unsteady computational fluid dynamic (CFD) analysis was undertaken. Both simulated and experimental results indicated that near the rotating disk, (i) a large amount of the ingestion gas will turn around and flow out the cavity due to the impact of the centrifugal force and the Coriolis force, (ii) a small amount of ingestion gas will mix transiently with the sealing air inside the cavity, whereas near the static disk, (iii) the ingestion gas will flow into the cavity along the static wall and mix with the sealing air.

scholarly journals Optimized Time-Resolved Echo Particle Image Velocimetry– Particle Tracking Velocimetry Measurements Elucidate Blood Flow in Patients With Left Ventricular Thrombus

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Kaushik Sampath ◽  
Thura T. Harfi ◽  
Richard T. George ◽  
Joseph Katz
Keyword(s):  
Blood Flow ◽  
Particle Image Velocimetry ◽  
Particle Tracking ◽  
Particle Tracking Velocimetry ◽  
Particle Image ◽  
Left Ventricular ◽  
Time Resolved ◽  
Ventricular Thrombus ◽  
Image Velocimetry ◽  
Contrast Ultrasound

Contrast ultrasound is a widely used clinical tool to obtain real-time qualitative blood flow assessments in the heart, liver, etc. Echocardiographic particle image velocimetry (echo-PIV) is a technique for obtaining quantitative velocity maps from contrast ultrasound images. However, unlike optical particle image velocimetry (PIV), routine echo images are prone to nonuniform spatiotemporal variations in tracer distribution, making analysis difficult for standard PIV algorithms. This study introduces optimized procedures that integrate image enhancement, PIV, and particle tracking velocimetry (PTV) to obtain reliable time-resolved two-dimensional (2D) velocity distributions. During initial PIV analysis, multiple results are obtained by varying processing parameters. Optimization involving outlier removal and smoothing is used to select the correct vector. These results are used in a multiparameter PTV procedure. To demonstrate their clinical value, the procedures are implemented to obtain velocity and vorticity distributions over multiple cardiac cycles using images acquired from four left ventricular thrombus (LVT) patients. Phase-averaged data elucidate flow structure evolution over the cycle and are used to calculate penetration depth and strength of left ventricular (LV) vortices, as well as apical velocity induced by them. The present data are consistent with previous time-averaged results for the minimum vortex penetration depth associated with LVT occurrence. However, due to decay and fragmentation of LV vortices, as they migrate away from the mitral annulus, in two cases with high penetration, there is still poor washing near the resolved clot throughout the cycle. Hence, direct examination of entire flow evolution may be useful for assessing risk of LVT relapse before prescribing anticoagulants.

Validation of Echodynamography in Comparison with Particle-image Velocimetry

2019 ◽  
Vol 41 (6) ◽  
pp. 336-352 ◽  
Author(s):  
Sri Oktamuliani ◽  
Naoya Kanno ◽  
Moe Maeda ◽  
Kaoru Hasegawa ◽  
Yoshifumi Saijo
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Velocity ◽  
Relative Error ◽  
Radial Direction ◽  
Particle Image ◽  
Left Ventricular ◽  
Perpendicular Direction ◽  
Percentage Error ◽  
Doppler Velocity ◽  
Image Velocimetry

Echodynamography (EDG) is a computational method to estimate and visualize two-dimensional flow velocity vectors by applying dynamic flow theories to color Doppler echocardiography. The EDG method must be validated if applied to human cardiac flow function. However, a few studies of flow estimated have compared by EDG to the flow data were acquired by other methods. In this study, EDG was validated by comparing the analysis of estimating and visualizing flow velocity vectors obtained by original particle image velocimetry (PIV) based on a left ventricular (LV) phantom hydrogel (in vitro studies) and by EDG based on the virtual Doppler velocity. Velocity measured by PIV method and velocity estimated by EDG method in the perpendicular direction and the radial direction were compared. Regression analysis for the velocity estimated in the radial direction revealed an excellent correlation ([Formula: see text], slope = 0.96) and moderate correlation in the perpendicular direction ([Formula: see text], slope = 0.46). As revealed by the Bland–Altman plot, however, overestimations and higher relative error were observed in the perpendicular direction (0.51 ± 2.75 mm/s) and in the radial direction (–2.15 ± 21.13 mm/s). The percentage error of the norm-wise relative error of the velocity discrepancy is less than [Formula: see text], and velocity magnitude followed the same trends and are of comparable magnitude. These findings indicate that good estimates of velocity can be obtained by the EDG method. Therefore, the EDG method was appropriate for estimating and visualizing velocity vectors in clinical studies for higher measurement accuracy and reliability. The clinical in vivo application showed that the EDG method has the ability to visualize blood flow velocity vectors and differentiate the clinical information of vortex parameters both in normal and abnormal LV subjects. In conclusion, the EDG method has potentially greater clinical acceptance as a tool assessment of LV during the cardiac cycle.

Echocardiographic Particle Image Velocimetry: A Novel Technique for Quantification of Left Ventricular Blood Vorticity Pattern

2010 ◽  
Vol 23 (1) ◽  
pp. 86-94 ◽  
Author(s):  
Arash Kheradvar ◽  
Helene Houle ◽  
Gianni Pedrizzetti ◽  
Giovanni Tonti ◽  
Todd Belcik ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Left Ventricular ◽  
Novel Technique ◽  
Image Velocimetry
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