lifex-cfd: An open-source computational fluid dynamics solver for cardiovascular applications

Africa, Pasquale Claudio; Fumagalli, Ivan; Bucelli, Michele; Zingaro, Alberto; Fedele, Marco; Dede', Luca; Quarteroni, Alfio

doi:10.1016/j.cpc.2023.109039

Cited by 15 publications

(2 citation statements)

References 110 publications

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“…To numerically solve system (3), we employ a BDF first-order semi-implicit scheme [73] for time discretization and ℙ 1 − ℙ 1 Finite Elements for space discretization, together with SUPG/PSPG stabilization technique [86]. At each time step, the corresponding linear system is solved with a Simple preconditioned GM-RES method, implemented in the multi-physics high performance library life x [1, 2] (https://lifex.gitlab.io/) based on the deal.II core [4].…”

Section: Methodsmentioning

confidence: 99%

Cardiac hemodynamics computational modeling including chordae tendineae, papillaries, and valves dynamics

Crispino,

Bennati,

Vergara

2024

Preprint

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In the context of dynamic image-based computational fluid dynamics (DIB-CFD) modeling of cardiac system, the role of sub-valvular apparatus (chordae tendineae and papillary muscles) and the effects of different mitral valve (MV) opening/closure dynamics, have not been systemically determined. To provide a partial filling of this gap, in this study we performed DIB-CFD numerical experiments in the left ventricle, left atrium and aortic root, with the aim of highlighting the influence on the numerical results of two specific modeling scenarios: i) the presence of the sub-valvular apparatus, consisting of chordae tendineae and papillary muscles; ii) different MV dynamics models accounting for different use of leaflet reconstruction from imaging. This is performed for one healthy and one MV regurgitant subjects. Specifically, a systolic wall motion is reconstructed from time-resolved Cine-MRI images and imposed as boundary condition for the CFD numerical simulation. Analyzing the numerical results, we found that sub-valvular apparatus do not affect the global fluid dynamics quantities, although it creates local variations, such as the developing of vortexes or flow disturbances, which lead to different stress distributions on cardiac structures. Moreover, different MV dynamics are considered starting from Cine-MRI MV segmentation at different temporal configurations, and then they are compared and managed numerically through a resistive approach. The obtained results highlight the importance of including a sophisticated diastolic model of MV dynamics, which accounts for MV geometries during diastasis and A-wave, in terms of describing the disturbed flow and ventricular turbulence.

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Section: Methodsmentioning

confidence: 99%

Cardiac hemodynamics computational modeling including chordae tendineae, papillaries, and valves dynamics

Crispino,

Bennati,

Vergara

2024

Preprint

View full text Add to dashboard Cite

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“…To numerically solve system (1), we used first-order Finite Elements together with first order semi-implicit discretization in time [51]. The numerical scheme was stabilized by means of the SUPG-PSPG scheme [52] implemented in the multiphysics high performance library life x [53, 54] (https://lifex.gitlab.io/) based on the deal.II core [55]. We run the simulations using 192 parallel processes on the GALILEO100 supercomputer (https://www.hpc.cineca.it/hardware/galileo100) at the CINECA high-performance computing center (Italy).…”

Section: Methodsmentioning

confidence: 99%

Image-based computational fluid dynamics to compare two mitral valve reparative techniques for the prolapse

Bennati,

Puppini,

Giambruno

et al. 2023

Preprint

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ObjectiveNowadays, the treatment of mitral valve prolapse involves two distinct repair techniques: chordal replacement (Neochordae technique) and leaflet resection (Resection technique). However, there is still a debate in the literature about which is the optimal one. In this context, we performed an image-based computational fluid dynamic study to evaluate blood dynamics in the two surgical techniques.MethodsWe considered a healthy subject (H) and two patients (N and R) who underwent surgery for the prolapse of the posterior leaflet and were operated with the Neochordae and Resection technique, respectively. Computational Fluid Dynamics (CFD) was employed with prescribed motion of the entire left heart coming from cine-MRI images, with a Large Eddy Simulation model to describe the transition to turbulence and a resistive method for managing valve dynamics. We created three different virtual scenarios where the operated mitral valves were inserted in the same left heart geometry of the healthy subject to study the differences attributed only to the two techniques.ResultsWe compared the three scenarios by quantitatively analyzing ventricular velocity patterns and pressures, transition to turbulence, and the ventricle ability to prevent thrombi formation. From these results we found that both the operated cases were able to restore almost physiological blood dynamic conditions, with some differences due to the reduced mobility of the Resection posterior leaflet. Conclusions: Our findings suggest that the Neochordae technique developed a slightly more physiological flow with respect to the Resection technique. The latter gave rise to a different direction of the mitral jet during diastole increasing the turbulence that is associated with ventricular effort and hemolysis, with also a larger ability to washout the ventricular apex preventing from thrombi formation.

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Modeling isovolumetric phases in cardiac flows by an Augmented Resistive Immersed Implicit Surface method

Zingaro,

Bucelli,

Fumagalli

et al. 2023

Numer Methods Biomed Eng

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A major challenge in the computational fluid dynamics modeling of the heart function is the simulation of isovolumetric phases when the hemodynamics problem is driven by a prescribed boundary displacement. During such phases, both atrioventricular and semilunar valves are closed: consequently, the ventricular pressure may not be uniquely defined, and spurious oscillations may arise in numerical simulations. These oscillations can strongly affect valve dynamics models driven by the blood flow, making unlikely to recovering physiological dynamics. Hence, prescribed opening and closing times are usually employed, or the isovolumetric phases are neglected altogether. In this article, we propose a suitable modification of the Resistive Immersed Implicit Surface (RIIS) method (Fedele et al., Biomech Model Mechanobiol 2017, 16, 1779–1803) by introducing a reaction term to correctly capture the pressure transients during isovolumetric phases. The method, that we call Augmented RIIS (ARIIS) method, extends the previously proposed ARIS method (This et al., Int J Numer Methods Biomed Eng 2020, 36, e3223) to the case of a mesh which is not body‐fitted to the valves. We test the proposed method on two different benchmark problems, including a new simplified problem that retains all the characteristics of a heart cycle. We apply the ARIIS method to a fluid dynamics simulation of a realistic left heart geometry, and we show that ARIIS allows to correctly simulate isovolumetric phases, differently from standard RIIS method. Finally, we demonstrate that by the new method the cardiac valves can open and close without prescribing any opening/closing times.

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lifex-cfd: An open-source computational fluid dynamics solver for cardiovascular applications

Cited by 15 publications

References 110 publications

Cardiac hemodynamics computational modeling including chordae tendineae, papillaries, and valves dynamics

Cardiac hemodynamics computational modeling including chordae tendineae, papillaries, and valves dynamics

Image-based computational fluid dynamics to compare two mitral valve reparative techniques for the prolapse

Modeling isovolumetric phases in cardiac flows by an Augmented Resistive Immersed Implicit Surface method

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