Kairong Qin^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 13-14, 2019, DOI:10.32604/mcb.2019.05703

Abstract Common carotid arteries (CCAs) are the major arteries supplying blood to the brain, and the hemodynamic variables in which are closely associated with the cardiovascular diseases. Exercise can induce the hemodynamic responses in the CCAs, including variations in blood pressure, circumferential stretch, and wall shear stress (WSS). Mechanosensors in the endothelial cells (ECs) are able to sense and distinguish these variations as mechanical signals, and transmit them into the interior of cells to affect cellular morphology and gene expression. Notably, reasonable exercises improve arterial structure and function, while unreasonable exercises cause endothelial dysfunction. Therefore, studies on the modulation of common… More >

Qi Zhang¹, Bin Gao¹, Yue Shi¹, Chang Yu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 247-262, 2018, DOI: 10.31614/cmes.2018.04082

Abstract Although pulsatile ECMO, as novel kinds of ECMO, has been attracted more and more attention, the differences of the hemodynamic effects of the pulsatile ECMO on the aorta, the cerebral perfusion, and left ventricular work were still under-investigated. The aim of this study was to clarify the hemodynamic differences of the cardiovascular system between the pulsatile and non-pulsatile VA ECMO. In this study, three ECMO support modes, named as “constant flow mode”, “co-pulse mode” and “counter pulse mode”, were designed. The computational fluid dynamics (CFD) study was carried out. The distribution of the oxygenated blood, the blood velocity vector, the… More >

Yohsuke Imai, Hitoshi Kondo, Young Ho KANG, Takuji Ishikawa Chwee Teck Lim, Takami Yamaguchi

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.3, pp. 205-206, 2009, DOI:10.3970/icces.2009.009.205

Abstract Malaria is one of the most serious infectious diseases on earth. We have about five hundred million patients with two million deaths. When a malaria parasite invades and matures inside a red blood cell (RBC), the infected RBC (IRBC) becomes stiffer and cytoadherent. We propose a numerical model of hemodynamics arising from malaria infection. Our model is based on a Lagrangian and free mesh method (particle) method. A spring network model is employed to compute elastic force generated by the deformation of IRBC membrane. Adhesive property of IRBCs to surrounding cells is also expressed by using a local spring model.… More >

Xi Zhao^∗, Youjun Liu^∗,†, Wenxin Wang^∗

Molecular & Cellular Biomechanics, Vol.12, No.1, pp. 49-66, 2015, DOI:10.3970/mcb.2015.012.049

Abstract Purpose: Sequential graft and Y-type graft are two different surgical procedures in coronary artery bypass grafting (CABG). The hemodynamic environment of them are different, that may cause different short-term surgical result and long-term patency. In this study, the short-term and long-term result of sequential and Y-type graft was discussed by comparing the hemodynamics of them. Materials and Methods: Two postoperative 3-dimensional (3D) models were built by applying different graft on a patient-specific 3D model with serious stenosis. Then zero-dimensional (0D)/3D coupled simulation was carried out by coupling the postoperative 3D models with a 0D lumped parameter model of the cardiovascular… More >

Bhaskar Chandra Konala^∗, Ashish Das^∗, Rupak K Banerjee^∗,†

Molecular & Cellular Biomechanics, Vol.8, No.1, pp. 1-20, 2011, DOI:10.3970/mcb.2011.008.001

Abstract Hemodynamic endpoints such as flow and pressure drop are often measured during angioplasty procedures to determine the functional severity of a coronary artery stenosis. There is a lack of knowledge regarding the influence of compliance of the arterial wall-stenosis on the pressure drop under hyperemic flows across coronary lesions. This study evaluates the influence in flow and pressure drop caused by variation in arterial-stenosis compliance for a wide range of stenosis severities. The flow and pressure drop were evaluated for three different severities of stenosis and tested for limiting scenarios of compliant models. The Mooney-Rivlin model defined the non-linear material… More >

Abhijit Sinha Roy^*, Lloyd H. Back^†, Rupak K. Banerjee^‡

Molecular & Cellular Biomechanics, Vol.5, No.4, pp. 229-246, 2008, DOI:10.3970/mcb.2008.005.229

Abstract The in vivo and ex vivo compliance of arteries are expected to be closely related and estimated. Fluid-structure interaction analysis can assess the agreement between the two compliances. To evaluate this hypothesis, a pulsatile fluid-structure interaction analysis of blood flow in femoral artery of a dog was conducted using: (1) measured in vivo mean pressure (72.5 mmHg), mean pressure drop (0.59 mmHg), mean velocity (15.1 cm/sec); and (2) ex vivo measurements of non -- linear elastic properties of femoral artery. Additional analyses were conducted for physiological pressures (104.1 and 140.7 mmHg) and blood flow using a characteristic linear pressure --… More >

E. Shaik^∗, K.A. Hoffmann^∗, J-F. Dietiker^∗

Molecular & Cellular Biomechanics, Vol.4, No.1, pp. 41-54, 2007, DOI:10.3970/mcb.2007.004.041

Abstract A potential interaction between the local hemodynamics and the artery wall response has been suggested for vascular graft failure by intimal hyperplasia (IH). Among the various hemodynamic factors, wall shear stress has been implicated as the primary factor responsible for the development of IH. In order to explore the role of hemodynamics in the formation of IH in end-to-side anastomosis, computational fluid dynamics is employed. To validate the numerical simulations, comparisons with existing experimental data are performed for both steady and pulsatile flows. Generally, good agreement is observed with the velocity profiles whereas some discrepancies are found in wall shear… More >

Zhou Zhao¹, Boyan Mao², Youjun Liu², Haisheng Yang², Yu Chen^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 229-245, 2018, DOI: 10.31614/cmes.2018.04192

Abstract In coronary artery bypass grafting (CABG), graft’s poor instant patency may lead to an abnormal hemodynamic environment in anastomosis, which could further cause graft failure after the surgery. This paper investigates the graft hemodynamics with different instant patency, and explores its effect on graft postoperative efficiency. Six CABG 0D/3D coupling multi-scale models which used left internal mammary artery (LIMA) and saphenous vein (SVG) as grafts were constructed. Different types of grafts were examined in the models, including normal grafts, grafts with competitive flow and grafts with anastomotic stenosis. Simulation results indicated that comparing with SVG grafts, there was a greater… More >

Sihan Chen¹, Bao Li¹, Haisheng Yang¹, Jianhang Du², Xiaoling Li², Youjun Liu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 149-162, 2018, DOI: 10.31614/cmes.2018.04133

Abstract Enhanced external counterpulsation (EECP) is able to treat myocardial ischemia, which is usually caused by coronary artery stenosis. However, the underlying mechanisms regarding why this technique is effective in treating myocardial ischemia remains unclear and there is no patient-specific counterpulsation mode for different rates of coronary artery stenosis in clinic. This study sought to investigate the hemodynamic effect of varied coronary artery stenosis rates when using EECP and the necessity of adopting targeted counterpulsation mode to consider different rates of coronary artery stenosis. Three 3-dimensional (3D) coronary models with different stenosis rates, including 55% (Model 1), 65% (Model 2), and… More >

Guangliang Pan¹, Yu Chang^1,*, Mingrui Fu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 199-213, 2018, DOI: 10.31614/cmes.2018.04080

Abstract Patients with extracorporeal membrane oxygenation still suffer from high rates of complication that linked to the flow field within the blood pump. So it is essential to optimise the geometry of the pump. The specification of shroud design is arguably the necessary design parameter in the centrifugal pump. However, the hemodynamic performances of the different shroud designs have not been studied extensively. In this study, ten different shroud designs were made and divided into two groups as the different covering locations (A: Covering the blade leading edge, B: Covering the blade trailing edge). In every group, six shroud designs with… More >