Investigation of the Blood Flow and Mitral-Septal Opposition in the Left Ventricle With the Obstructive Hyperthrophic Cardiomyopathy During Systole Using Fluid-Structure Interaction Technique

2010 ◽  
Author(s):  
Ahmad Moghaddaszade Kermani ◽  
Afzal Suleman
Keyword(s):  
Blood Flow ◽  
Mitral Valve ◽  
Left Ventricle ◽  
Fluid Structure Interaction ◽  
Left Ventricular ◽  
Anterior Leaflet ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Narrow Passage ◽  
Aortic Orifice

In this article, fluid-structure interaction methodology was used to analyze the blood flow and Mitral-Septal opposition in the Left ventricle with the Obstructive Hyperthrophic Cardiomyopathy (OHCM). The geometry of the computational model includes the diseased left ventricle with thickened septum and Mitral valve. A semi-ellipsoidal geometry was developed with the dimensions, extracted from MR images of the diseased left ventricle. Also, the geometry of the Mitral valve was created using anatomical data provided in literature [1]. The three element Windkessel model and atrial pressure [2, 3] were used to introduce mass flow and pressure boundary conditions to the aortic orifice and left atrium respectively. Effect of the fibers was taken into account by varying the Young’s modulus of the mitral valve tissue with circumferential and radial coordinates. The fluid-structure interaction algorithm started at the beginning of the systole (when the mitral valve is fully open with zero stress) by applying the left ventricular pressure on the left ventricular wall and aortic mass flow outlet on the aortic orifice. The Navier-Stokes equations were solved with SIMPLE algorithm and finite volume method to calculate the blood flow inside the diseased left ventricle. The calculated pressure was applied to the surface of the mitral valve and the structural model of the tissue was solved using non-linear finite element. The deformation of the mitral valve was transferred to the blood by moving the fluid mesh. In the next time step, the same procedure was repeated with the new mesh. This algorithm was followed up to the end of the systole. The thickened septum creates a narrow passage for the blood flowing out of the left ventricle, thus a jet of blood flow is developed in this narrow passage which applies high shear stress on the anterior leaflet of the mitral valve. The drag force deforms the anterior leaflet toward the septum, obstructing the blood flow rushing toward the aortic orifice.

Fluid-Structure Interaction Simulation of Blood Flow Inside a Diseased Left Ventricle With Obstructive Hypertrophic Cardiomyopathy in Early Systole

2009 ◽  
Author(s):  
Ahmad Moghaddaszade-Kermani ◽  
Peter Oshkai ◽  
Afzal Suleman
Keyword(s):  
Blood Flow ◽  
Hypertrophic Cardiomyopathy ◽  
Left Ventricle ◽  
Fluid Structure Interaction ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Systolic Phase

Mitral-Septal contact has been proven to be the cause of obstruction in the left ventricle with hypertrophic cardiomyopathy (HC). This paper presents a study on the fluid mechanics of obstruction using two-way loosely coupled fluid-structure interaction (FSI) methodology. A parametric model for the geometry of the diseased left ventricular cavity, myocardium and mitral valve has been developed, using the dimensions extracted from magnetic resonance images. The three-element Windkessel model [1] was modified for HC and solved to introduce pressure boundary condition to the aortic aperture in the systolic phase. The FSI algorithm starts at the beginning of systolic phase by applying the left ventricular pressure to the internal surface of the myocardium to contract the muscle. The displacements of the myocardium and mitral leaflets were calculated using the nonlinear finite element hyperelastic model [2] and subsequently transferred to the fluid domain. The fluid mesh was moved accordingly and the Navier-Stokes equations were solved in the laminar regime with the new mesh using the finite volume method. In the next time step, the left ventricular pressure was increased to contract the muscle further and the same procedure was repeated for the fluid solution. The results show that blood flow jet applies a drag force to the mitral leaflets which in turn causes the leaflet to deform toward the septum thus creating a narrow passage and possible obstruction.

Fluid-Structure Interaction Modeling and Validation of Idealized Left Ventricular Blood Flow

2020 ◽  
Author(s):  
Megan Laughlin ◽  
Sam Stephens ◽  
Hanna Jensen ◽  
Morten Jensen ◽  
Paul Millett
Keyword(s):  
Blood Flow ◽  
Fluid Structure Interaction ◽  
Flow Analysis ◽  
Left Ventricular ◽  
Maximum Pressure ◽  
Flow Loop ◽  
Fluid Structure ◽  
Pressure Drops ◽  
Structure Interaction ◽  
Custom Made

Abstract Fluid Structure Interaction (FSI) models are an essential tool in understanding the complex coupling of blood flow in the heart. The objective of this study is to establish a method of comparing data obtained from FSI models and benchtop measurements from phantoms to identify sources of flow changes for use in intraventricular flow analysis. Two geometries are considered: 1) a vascular model consisting of a straight channel with an ellipsoidal swell and 2) an idealized left ventricle (LV) model representative “acorn” shape. Two phantoms are created for each of the two geometries: 3D printed rigid phantoms from a resin and custom-made tissue-mimicking phantoms from a medical gel. Benchtop measurements are made using the phantoms within a custom flow loop setup with pulsatile flow. Computational Fluid Dynamics (CFD) simulations are conducted with a Smoothed Particle Hydrodynamics (SPH) model. The two flow channel geometries utilized in the experiments are replicated for the simulations. The cavity walls are defined by ghost particles that are rigidly fixed. Maximum pressure drops were 57 mmHg and 196 mmHg for the rigid swell and rigid LV, respectively, whereas maximum pressure drops were 155 mmHg for the gel swell and 140 mmHg for the gel LV. Calculations from the simulations resulted in a maximum pressure drop of 55 mmHg for the swell and 110 mmHg for the LV. This data serves as a first step in corroborating our methodology to utilize the information obtained from both methods to identify and better understand mutual sources of changes in flow patterns.

scholarly journals A coupled mitral valve—left ventricle model with fluid–structure interaction

2017 ◽  
Vol 47 ◽  
pp. 128-136 ◽  
Author(s):  
Hao Gao ◽  
Liuyang Feng ◽  
Nan Qi ◽  
Colin Berry ◽  
Boyce E. Griffith ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Left Ventricle Model

Modeling of aortic valve stenosis using fluid-structure interaction method

Perfusion ◽  
2021 ◽  
pp. 026765912199854
Author(s):  
Mohammad Javad Ghasemi Pour ◽  
Kamran Hassani ◽  
Morteza Khayat ◽  
Shahram Etemadi Haghighi
Keyword(s):  
Blood Flow ◽  
Aortic Valve ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Relaxation Phase ◽  
Exercise Condition ◽  
Time Dependent Domain ◽  
Comparison Of The Results

Background and objectives: Fluid structure interaction (FSI) is defined as interaction of the structures with contacting fluids. The aortic valve experiences the interaction with blood flow in systolic phase. In this study, we have tried to predict the hemodynamics of blood flow through a normal and stenotic aortic valve in two relaxation and exercise conditions using a three-dimensional FSI method. Methods: The aorta valve was modeled as a three-dimensional geometry including a normal model and two others with 25% and 50% stenosis. The geometry of the aortic valve was extracted from CT images and the models were generated by MMIMCS software and then they were implemented in ANSYS software. The pulsatile flow rate was used for all cases and the numerical simulations were conducted based on a time-dependent domain. Results: The obtained results including the velocity, pressure, and shear stress contours in different systolic time sequences were explained and discussed. The maximum blood flow velocity in relaxation phase was obtained 1.62 m/s (normal valve), 3.78 m/s (25% stenosed valve), and 4.73 m/s (50% stenosed valve). In exercise condition, the maximum velocities are 2.86, 4.32, and 5.42 m/s respectively. The maximum blood pressure in relaxation phase was calculated 111.45 mmHg (normal), 148.66 mmHg (25% stenosed), and 164.21 mmHg (50% stenosed). However, the calculated values in exercise situation were 129.57, 163.58, and 191.26 mmHg. The validation of the predicted results was also conducted using existing literature. Conclusions: We believe that such model are useful tools for biomechanical experts. The further studies should be done using experimental data and the data are implemented on the boundary conditions for better comparison of the results.

Fluid-Structure Interaction Simulation of the Edge-to-Edge Repair of the Mitral Valve in Functional and Degenerative States

2012 ◽  
Author(s):  
K. D. Lau ◽  
G. Burriesci ◽  
V. Díaz-Zuccarini
Keyword(s):  
Mitral Valve ◽  
Fluid Structure Interaction ◽  
Mitral Valve Regurgitation ◽  
Fluid Structure ◽  
Explicit Finite Element ◽  
Structure Interaction ◽  
Modelling Techniques ◽  
Induced Stresses ◽  
Annular Dilation ◽  
Ventricular Filling

The most common dysfunction of the mitral valve (MV) is mitral valve regurgitation (MVR) which accounts for approximately 70% of native MV dysfunction [1]. During closure, abnormal amounts of retrograde flow enter the left atrium altering ventricular haemodynamics, an issue which can lead to cardiac related pathologies. MVR is caused by a variety of different mechanisms which are either degenerative (myxomatous degeneration) or functional (annular dilation or papillary muscle displacement) [2]. Correction of MVR is performed by repairing existing valve anatomy or replacement with a prosthetic substitute, however repair is preferred as mortality rates are reduced (2.0% against 6.1% for replacement) along with other valve related complications [3]. A common and popular method of repair is the edge-to-edge repair (ETER), which aims to correct MVR by surgically connecting the regurgitant region through reducing the inter-leaflet distance. Although MV function is improved in systole, induced stresses are significantly increased in diastole where the MV is typically in a low state of stress. In order to assess the effect of this technique in diastole, where the dynamics of both the MV and ventricular filling are disrupted it is required to use fluid-structure interaction (FSI) modelling techniques. Here a FSI model of the of the MV has been described, using this model the resulting induced stresses from the ETER in both functional and degenerative states of the MV have been simulated and assessed using the explicit finite element code LS-DYNA.

Axisymmetric fluid-structure interaction model of the left ventricle

2003 ◽  
pp. 1669-1672 ◽  
Author(s):  
Dimitri Deserranno ◽  
Zoran B. Popovic ◽  
Neil L. Greenberg ◽  
Mohammad Kassemi ◽  
James D. Thomas
Keyword(s):  
Left Ventricle ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Fluid Structure ◽  
Structure Interaction
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