Numerical investigation on effect of leaflet thickness on structural stresses developed in a bileaflet mechanical heart valve for its sustainable manufacturing

Abbas, Syed Samar; Nasif, Mohammad Shakir; Said, Mohd Ismid Mohd; Al-Waked, Rafat; Kadhim, Saleem Khalefa

doi:10.1051/matecconf/201713104004

Cited by 5 publications

(3 citation statements)

References 16 publications

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“…Optimization of the design of mechanical valves is achieved using computational and experimental methods [9][10][11] to improve the velocity profiles and minimize the complications that are caused by prosthetics. Modern numerical simulation methods such as DNS, URANS, LES, and DES are used for calculations [12][13][14]. Hemodynamic and hydrodynamic tests of heart valves are an important step for conducting preclinical research of a new device.…”

Section: Methodsmentioning

confidence: 99%

Hydrodynamic Noise of Pulsating Jets through Bileaflet Mechanical Mitral Valve

Voskoboinick

Voskoboinyk

Chertov

et al. 2020

BioMed Research International

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Experimental research results of hydrodynamic noise of pulsating flow through a bileaflet mechanical mitral valve are presented. The pulsating flow of pure water corresponds to the diastolic mode of the cardiac rhythm heart. The valve was located between the model of the left atrium and the model of the left ventricle of the heart. A coordinate device, on which a block of miniature sensors of absolute pressure and pressure fluctuations was installed, was located inside the model of the left ventricle. It is found that the hydrodynamic noise of the pulsating side jet of the semiclosed valve is higher than for the open valve. The pressure fluctuation levels gradually decrease with the removal from the mitral valve. It is established that at the second harmonic of the pulsating flow frequency, the spectral levels of the hydrodynamic noise of the semiclosed bileaflet mechanical mitral valve are almost 5 times higher than the open valve. With the removal from the mitral valve, spectral levels of hydrodynamic noise are decreased, especially strongly at the frequency of the pulsating water flow and its higher harmonics.

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Section: Methodsmentioning

confidence: 99%

Hydrodynamic Noise of Pulsating Jets through Bileaflet Mechanical Mitral Valve

Voskoboinick

Voskoboinyk

Chertov

et al. 2020

BioMed Research International

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“…FSI of blood and heart valve leaflets could be considered as a coupled system consisting of two domains, blood being the fluid domain and leaflets of the heart valves being the structural domain, where neither domain can be solved while separated from the other. 10,11 For the blood domain, the governing equations are the three-dimensional unsteady Navier–Stokes and continuity equations in their incompressible, index notation form:…”

Section: Introductionmentioning

confidence: 99%

State-of-the-art numerical fluid–structure interaction methods for aortic and mitral heart valves simulations: A review

2021

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Numerical fluid–structure interaction (FSI) methods have been widely used to predict the cardiac mechanics and associated hemodynamics of native and artificial heart valves (AHVs). Offering a high degree of spatial and temporal resolution, these methods circumvent the need for cardiac surgery to assess the performance of heart valves. Assessment of these FSI methods in terms of accuracy, realistic modeling, and numerical stability is required, which is the objective of this paper. FSI methods could be classified based on how the computational domain is discretized, and on the coupling techniques employed between fluid and structure domains. The grid-based FSI methods could be further classified based on the kinematical description of the computational fluid (blood) grid, being either fixed grid, moving grid, or combined fixed–moving grid methods. The review reveals that fixed grid methods mostly cause imprecise calculations of flow parameters near the blood–leaflet interface. Moving grid methods are more accurate, however they require cumbersome remeshing and smoothing. The combined fixed–moving grid methods overcome the shortcomings of fixed and moving grid methods, but they are computationally expensive. The mesh-free methods have been able to encounter the problems faced by grid-based methods; however, they have been only limitedly applied to heart valve simulations. Among the coupling techniques, explicit partitioned coupling is mostly unstable, however the implicit partitioned coupling not only has the potential to be stable but is also comparatively cheaper. This in-depth review is expected to be helpful for the readers to evaluate the pros and cons of FSI methods for heart valve simulations.

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“…In term of implantation position, it is found that under similar physiological conditions, the von-mises stresses of the BMHV placed at the root of aorta with axisymmetric sinus are 47% higher than stresses of the BMHV placed at the aorta with axisymmetric bulb. In addition, the leaflet thickness has a significant effect on the flow of the blood [21]. When the leaflet thickness is reduced by 0.1 mm, the equivalent stress is 75% higher than the allowable equivalent stress.…”

mentioning

confidence: 99%

Transient Study of Flow and Cavitation Inside a Bileaflet Mechanical Heart Valve

Gao

Jin

et al. 2020

Applied Sciences

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A mechanical heart valve (MHV) is an effective device to cure heart disease, which has the advantage of long life and high reliability. Due to the hemodynamic characteristics of blood, mechanical heart valves can lead to potential complications such as hemolysis, which have damage to the blood elements and thrombosis. In this paper, flowing features of the blood in the valve are analyzed and the cavitation mechanism in bileaflet mechanical heart valve (BMHV) is studied. Results show that the water hammer effect and the high-speed leakage flow effect are the primary causes of the cavitation in the valve. Compared with the high-speed leakage flow effect, the water hammer has a greater effect on the cavitation strength. The valve goes through four kinds of working condition within one heart beating period, including, fully opening stage, closing stage and fully closing stage. These four stages, respectively, make up 8.5%, 16.1%, 4.7% and 70.7% of the total period. The cavitation occurs on the fully closing stage. When the valve is in closing stage, the high pressure downstream of the valve lasts for about 20 ms and the high-speed leakage flow lasts for about 200 ms. This study systematically analyzes the causes of cavitation emerged in the process of periodic motion, which proposes the method for characterizing the intensity of the cavitation, and can be referred to for the cavitation suppression of the BHMV and similar valves.The main concerns of valve research have been the performance [3] and the internal flow properties [4]. In order to study the hydrodynamic characteristics of the mechanical heart valve, numerical simulation based on CFD is one powerful tool to study cardiovascular risk factors, especially those related to mechanical properties of artificial heart valve [5]. It is an effective way to improve the performance of the valve by structure optimization, which is applicable to many valves +(e.g., Tesla valve) [6,7], and the BMHV is no exception. Many works on the effect of geometric features of the BMHV on blood stream are performed by simulations in the past years. For example, it has been found that the maximum shear stress within the range of platelet activation can lead to thrombosis [8,9]. The strategy of self-adapting mesh is used to capture the motion of the leaflet realizing by user-defined functions (UDF) in the commercial software [10]. It is found that the valve leaflet and the valve pivot are continuously exposed to shear stress higher than 52.3 Pa, which can cause damage to the platelets. The problem of thrombosis can be solved by increasing the curvature of the leaflet of the bileaflet mechanical heart valve [11]. Results show that increasing the curvature of the leaflet can provide larger central circulation area and reduce the risk of thrombosis. Another way [12] is proposed by using BMHV with SH coating to reduce the interaction between blood and BMHV. Based on effect analysis of BMHV with SH coating on blood substances and hemodynamics, the performance index of BMHV with SH coating, w...

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Numerical investigation on effect of leaflet thickness on structural stresses developed in a bileaflet mechanical heart valve for its sustainable manufacturing

Cited by 5 publications

References 16 publications

Hydrodynamic Noise of Pulsating Jets through Bileaflet Mechanical Mitral Valve

Hydrodynamic Noise of Pulsating Jets through Bileaflet Mechanical Mitral Valve

State-of-the-art numerical fluid–structure interaction methods for aortic and mitral heart valves simulations: A review

Transient Study of Flow and Cavitation Inside a Bileaflet Mechanical Heart Valve

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