scholarly journals TRACKER: A particle image tracking (PIT) technique dedicated to nonsmooth motions involved in granular packings

2013 ◽  
Author(s):  
Gaël Combe ◽  
Vincent Richefeu
Keyword(s):  
Particle Image ◽  
Image Tracking ◽  
Granular Packings

Time-Resolved Echo-Particle Image/Tracking Velocimetry Measurement of Interactions Between Native Cardiac Output and Veno-Arterial ECMO Flows

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Zeng Zhang ◽  
Xun Zhou ◽  
Alejandro Suarez-Pierre ◽  
Cecillia Lui ◽  
Sean Kearney ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Flow Rate ◽  
Aortic Root ◽  
Particle Image ◽  
Blind Deconvolution ◽  
Secondary Flows ◽  
Time Resolved ◽  
Image Tracking ◽  
The Impact ◽  
Ecmo Flow

Abstract Determination of optimal hemodynamic and pressure–volume loading conditions for patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) would benefit from understanding the impact of ECMO flow rates (QE) on the native cardiac output in the admixing zone, i.e., aortic root. This study characterizes the flow in the aortic root of a pig with severe myocardial ischemia using contrast-enhanced ultrasound particle image/tracking velocimetry (echo-PIV/PTV). New methods for data preprocessing are introduced, including autocontouring to remove surrounding tissues, followed by blind deconvolution to identify the centers of elongated bubble traces in images with low signal to noise ratio. Calibrations based on synthetic images show that this procedure increases the number of detected bubbles and reduces the error in their locations by 50%. Then, an optimized echo-PIV/PTV procedure, which integrates image enhancement with velocity measurements, is used for characterizing the time-resolved two-dimensional (2D) velocity distributions. Phase-averaged and instantaneous flow fields show that the ECMO flow rate influences the velocity and acceleration of the cardiac output during systole, and secondary flows during diastole. When QE is 3.0 L/min or higher, the cardiac ejection velocity, phase interval with open aortic valve, velocity-time integral (VTI), and mean arterial pressure (MAP) increase with decreasing QE, all indicating sufficient support. For lower QE, the MAP and VTI decrease as QE is reduced, and the deceleration during transition to diastole becomes milder. Hence, for this specific case, the optimal ECMO flow rate is 3.0 L/min.

scholarly journals Application of Genetic Algorithms to 3-Dimensional Particle Image Tracking

1995 ◽  
Vol 15 (Supplement1) ◽  
pp. 157-160
Author(s):  
Ryu-ichiro OHYAMA ◽  
Yasuhiko KUNITOU ◽  
Kiyoji KANEKO
Keyword(s):  
Genetic Algorithms ◽  
Particle Image ◽  
3 Dimensional ◽  
Image Tracking

Three-dimensional particle image tracking for dilute particle-liquid flows in a pipe

2002 ◽  
Vol 13 (8) ◽  
pp. 1206-1216 ◽  
Author(s):  
X-H Pan ◽  
R Luo ◽  
X-Y Yang ◽  
H-J Yang
Keyword(s):  
Particle Image ◽  
Three Dimensional ◽  
Image Tracking ◽  
Liquid Flows
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