Hemodynamic Assessment of Hollow-Fiber Membrane Oxygenators Using Computational Fluid Dynamics in Heterogeneous Membrane Models

2021 ◽  
Author(s):  
Daniele Dipresa ◽  
Panagiotis Kalozoumis ◽  
Michael Pflaum ◽  
Ariana Peredo ◽  
Bettina Wiegmann ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Blood Flow ◽  
Shear Stress ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Thrombus Formation ◽  
Shear Stresses ◽  
Fiber Membrane ◽  
Hemodynamic Assessment

Abstract Extracorporeal membrane oxygenation (ECMO) has been used clinically for more than 40 years as a bridge to transplantation, with hollow-fiber membrane (HFM) oxygenators gaining in popularity due to their high gas transfer and low flow resistance. In spite of the technological advances in ECMO devices, the inevitable contact of the perfused blood with the polymer hollow-fiber gas-exchange membrane, and the subsequent thrombus formation, limits their clinical usage to only 2-4 weeks. In addition, the inhomogeneous flow in the device can further enhance thrombus formation and limit gas-transport efficiency. Endothelialisation of the blood contacting surfaces of ECMO devices offers a potential solution to their inherent thrombogenicity. However, abnormal shear stresses and inhomogeneous blood flow might affect the function and activation status of the seeded endothelial cells (ECs). In this study, the blood flow through two HFM oxygenators, including the commercially-available iLA® MiniLung Petite Novalung (Xenios AG, Germany) and an experimental one for the rat animal model, was modelled using computational fluid dynamics (CFD), with a view to assessing the magnitude and distribution of the shear stress on the wall of the hollow fibers and flow fields in the oxygenators. This work demonstrated significant inhomogeneity in the flow dynamics of both oxygenators, with regions of high hollow-fiber wall shear stress and regions of stagnant flow, implying both regions of increased flow-induced blood damage and a variable flow-induced stimulation on seeded ECs in a biohybrid setting.

scholarly journals Computational Study of the Blood Flow in Three Types of 3D Hollow Fiber Membrane Bundles

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Jiafeng Zhang ◽  
Xiaobing Chen ◽  
Jun Ding ◽  
Katharine H. Fraser ◽  
M. Ertan Taskin ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Hollow Fiber ◽  
Computational Study ◽  
Hollow Fiber Membrane ◽  
Cfd Modeling ◽  
Fiber Membrane ◽  
Wall Shear ◽  
Average Wall Shear Stress

The goal of this study is to develop a computational fluid dynamics (CFD) modeling approach to better estimate the blood flow dynamics in the bundles of the hollow fiber membrane based medical devices (i.e., blood oxygenators, artificial lungs, and hemodialyzers). Three representative types of arrays, square, diagonal, and random with the porosity value of 0.55, were studied. In addition, a 3D array with the same porosity was studied. The flow fields between the individual fibers in these arrays at selected Reynolds numbers (Re) were simulated with CFD modeling. Hemolysis is not significant in the fiber bundles but the platelet activation may be essential. For each type of array, the average wall shear stress is linearly proportional to the Re. For the same Re but different arrays, the average wall shear stress also exhibits a linear dependency on the pressure difference across arrays, while Darcy's law prescribes a power-law relationship, therefore, underestimating the shear stress level. For the same Re, the average wall shear stress of the diagonal array is approximately 3.1, 1.8, and 2.0 times larger than that of the square, random, and 3D arrays, respectively. A coefficient C is suggested to correlate the CFD predicted data with the analytical solution, and C is 1.16, 1.51, and 2.05 for the square, random, and diagonal arrays in this paper, respectively. It is worth noting that C is strongly dependent on the array geometrical properties, whereas it is weakly dependent on the flow field. Additionally, the 3D fiber bundle simulation results show that the three-dimensional effect is not negligible. Specifically, velocity and shear stress distribution can vary significantly along the fiber axial direction.

Effect of the Red Blood Cells on the Primary Thrombus Formation

2007 ◽  
Author(s):  
Koichiro Yano ◽  
Daisuke Mori ◽  
Ken-ichi Tsubota ◽  
Takuji Ishikawa ◽  
Shigeo Wada ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Blood Flow ◽  
Blood Cell ◽  
Blood Cells ◽  
Thrombus Formation ◽  
The Other ◽  
Biochemical Processes ◽  
Mechanical Factors ◽  
Molecular Bridge

It has been pointed out that some mechanical factors play important roles in a series of physiological or biochemical processes during the thrombus formation. Recently, many studies including the authors’ work qualitatively demonstrated how the thrombus is regulated under the influences of the blood flow and the intercellular molecular bridge using computational fluid dynamics techniques[1–4]. They verified the importance of the balance of them in the process of the thrombus formation. However, few studies have taken into account the existence of the other cell constituents than the platelet such as red blood cell (RBC).

Computational simulation of CO2removal from gas mixtures by chemical absorbents in porous membranes

RSC Advances ◽  
2015 ◽  
Vol 5 (46) ◽  
pp. 36787-36797 ◽  
Author(s):  
Reza Fazaeli ◽  
Seyed Mohammad Reza Razavi ◽  
Mehdi Sattari Najafabadi ◽  
Rezvan Torkaman ◽  
Alireza Hemmati
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Hollow Fiber Membrane ◽  
Computational Simulation ◽  
Porous Membranes ◽  
Gas Mixture ◽  
Fiber Membrane ◽  
Chemical Absorption ◽  
Membrane Contactors ◽  
Dynamics Method

In this study chemical absorption of CO2from a N2/CO2gas mixture in tetramethylammonium glycinate ([N1111][Gly]) solution using hollow-fiber membrane contactors by employing the CFD (computational fluid dynamics) method was investigated.

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