Measurement of wall shear stress in an in vitro model of cerebral aneurysm at pulsatile flow(1D2 Cardiovascular Mechanics II)

2007 ◽  
Vol 2007.3 (0) ◽  
pp. S63
Author(s):  
Yoshinori Bando ◽  
Marie Oshima ◽  
Masamichi Oishi
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Cerebral Aneurysm ◽  
Pulsatile Flow ◽  
In Vitro Model ◽  
Cardiovascular Mechanics ◽  
Wall Shear ◽  
Vitro Model

Endothelial cells in culture: An in vitro model of the wall shear stress gradient effect

1998 ◽  
Vol 31 ◽  
pp. 173 ◽  
Author(s):  
O. Boutherin Falson ◽  
C. Haond ◽  
M. Chaslon ◽  
M. Moenner ◽  
S. Naili ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
In Vitro Model ◽  
Stress Gradient ◽  
Gradient Effect ◽  
Cells In Culture ◽  
Wall Shear Stress Gradient ◽  
Vitro Model

In vitro measurements of velocity and wall shear stress in a novel sequential anastomotic graft design model under pulsatile flow conditions

2014 ◽  
Vol 36 (10) ◽  
pp. 1233-1245 ◽  
Author(s):  
Foad Kabinejadian ◽  
Dhanjoo N. Ghista ◽  
Boyang Su ◽  
Mercedeh Kaabi Nezhadian ◽  
Leok Poh Chua ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Pulsatile Flow ◽  
Design Model ◽  
Flow Conditions ◽  
In Vitro Measurements ◽  
Wall Shear

Identification of Quantifiable Hemodynamic Factors in the Assessment of Cerebral Aneurysm Behavior On behalf of the Subcommittee on Biorheology of the Scientific and Standardization Committee of the ISTH

1996 ◽  
Vol 76 (01) ◽  
pp. 118-123 ◽  
Author(s):  
Arrmelle C Burleson ◽  
Vincent T Turitto
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Cerebral Aneurysm ◽  
Flow Recirculation ◽  
Treatment Techniques ◽  
Aneurysm Wall ◽  
Wall Shear ◽  
Intravascular Treatment ◽  
Experimental And Theoretical Studies

SummaryPrevious experimental and theoretical studies on the hemodynamics of saccular intracranial aneurysms have provided evidence that aneurysms tend to grow, thrombose and rupture when (1) wall shear stress and mural tension are increased compared to normal values, and (2) flow deviates from a laminar unidirectional pattern (for example flow recirculation). Aneurysm wall shear stress, however, is the only hemodynamic factor which has received special attention in terms of estimation. Additional flow-related parameters exist which could potentially bring increased insight into mechanisms for cerebral aneurysm behavior; they could also help categorize the severity of such malformations and design effective intravascular treatment techniques. The purpose of this paper is thus to present an overview of such hemodynamic factors that could assist in determining the geometries which present the greatest risks to patients. These parameters include (1) hemodynamic shear stress, (2) pressure and related stresses, (3) impingement force on the aneurysm wall, (4) inflow rate into the aneurysm, and (5) residence time of blood within the aneurysmal sac. In addition, these factors can also be currently estimated in an in vitro setting.

In-Vitro Blood Flow and Wall Shear Stress Measurements in Idealised and Patient Specific Models of the Carotid Artery Bifurcation

2008 ◽  
Author(s):  
Nicolas A. Buchmann ◽  
Mark C. Jermy
Keyword(s):  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Three Dimensional ◽  
Patient Specific ◽  
Specific Geometry ◽  
Wall Shear ◽  
Magnetic Resonance Imaging Mri ◽  
Vitro Model

This work presents Particle Image Velocimetry (PIV) measurements in idealised and patient specific human carotid artery bifurcations (CAB) under steady and pulsatile flow. The geometry and corresponding boundary conditions were obtained by Magnetic Resonance Imaging (MRI) and replicated in an in-vitro model. A complex three-dimensional flow structure exists inside the CAB and vorticity and wall shear stress data are used to quantify the differences between the idealised and patient specific geometry.

scholarly journals Investigation of Wall Shear Stress in Cardiovascular Research and in Clinical Practice—From Bench to Bedside

2021 ◽  
Vol 22 (11) ◽  
pp. 5635
Author(s):  
Katharina Urschel ◽  
Miyuki Tauchi ◽  
Stephan Achenbach ◽  
Barbara Dietel
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Cell Function ◽  
Computational Techniques ◽  
Apical Surface ◽  
Cardiovascular Research ◽  
Endothelial Cell Function ◽  
Wall Shear

In the 1900s, researchers established animal models experimentally to induce atherosclerosis by feeding them with a cholesterol-rich diet. It is now accepted that high circulating cholesterol is one of the main causes of atherosclerosis; however, plaque localization cannot be explained solely by hyperlipidemia. A tremendous amount of studies has demonstrated that hemodynamic forces modify endothelial athero-susceptibility phenotypes. Endothelial cells possess mechanosensors on the apical surface to detect a blood stream-induced force on the vessel wall, known as “wall shear stress (WSS)”, and induce cellular and molecular responses. Investigations to elucidate the mechanisms of this process are on-going: on the one hand, hemodynamics in complex vessel systems have been described in detail, owing to the recent progress in imaging and computational techniques. On the other hand, investigations using unique in vitro chamber systems with various flow applications have enhanced the understanding of WSS-induced changes in endothelial cell function and the involvement of the glycocalyx, the apical surface layer of endothelial cells, in this process. In the clinical setting, attempts have been made to measure WSS and/or glycocalyx degradation non-invasively, for the purpose of their diagnostic utilization. An increasing body of evidence shows that WSS, as well as serum glycocalyx components, can serve as a predicting factor for atherosclerosis development and, most importantly, for the rupture of plaques in patients with high risk of coronary heart disease.

In-Vitro Wall Shear Stress Measurements for Microfluid Flows by Using Second-Order SPE Micro-PIV

2007 ◽  
Author(s):  
Han-Sheng Chuang ◽  
Steven T. Wereley
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Measurement Errors ◽  
Pearson Correlation ◽  
Second Order ◽  
Bias Error ◽  
Central Difference ◽  
Micro Piv ◽  
Wall Shear

Conventional single pixel evaluation (SPE) significantly improves the spatial resolution of PIV measurements to the physical limit of a CCD camera based on the forward difference interrogation (FDI). This paper further enhances the computational algorithm to second-order accuracy by simply modifying the numerical scheme with the central difference interrogation (CDI). The proposed central difference scheme basically superposes the forward-time and the backward-time correlation domains, thus resulting in reduced bias error as well as rapid background noise elimination. An assessment of the CDI SPE algorithm regarding the measurement errors was achieved via numerous synthetic images subject to a four-roll mill flow. In addition, preliminary wall shear stress (WSS) measurements regarding different algorithms are also evaluated with an analytical turbulent boundary flow. CDI scheme showed a 0.32% error deviated from the analytical solution and improved the same error in FFT-based correlation correlation (FFT-CC) by 32.35%. To demonstrate the performance in practice, in-vitro measurements were implemented in a serpentine microchannel made of polydimethyl siloxane (PDMS) for both CDI SPE and spatial cross-correlation. A series of steady-state flow images at five specified regions of interest were acquired using micro-PIV system. Final comparisons of the WSS regarding the Pearson correlation coefficient, R2, between the numerical schemes and the simulations showed that an overall result was improved by CDI SPE due to the fine resolution and the enhanced accuracy.

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