Pith. sign in

REVIEW 4 major objections 7 minor 102 references

This paper introduces svMultiPhysics, an open-source C++ finite element solver that unifies cardiovascular fluid dynamics, solid mechanics, diffusion, and cardiac electrophysiology in a single computational framework.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-01 12:09 UTC pith:QHV3TWPM

load-bearing objection Solid infrastructure paper that inherits rather than demonstrates accuracy; useful to the community once a head-to-head svFSI check is added. the 4 major comments →

arxiv 2607.19631 v1 pith:QHV3TWPM submitted 2026-07-21 physics.flu-dyn

svMultiPhysics: a finite element-based solver for cardiovascular simulations

classification physics.flu-dyn
keywords svMultiPhysicscardiovascular simulationfinite element methodfluid-structure interactioncardiac electrophysiologySimVascularGPU accelerationpatient-specific modeling
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper presents svMultiPhysics, a new open-source finite element solver written in C++ that treats fluid dynamics, solid mechanics, scalar transport, and cardiac electrophysiology within one computational framework. The authors argue that because the code is an essentially direct line-by-line translation of the validated svFSI solver, it inherits that solver's numerical accuracy while gaining a more modular, extensible design and optional GPU-accelerated linear algebra. They support the claim with three patient-specific simulations — a rigid-wall abdominal aortic aneurysm CFD case, a monolithic ALE fluid–structure interaction case, and a biventricular electrophysiology case with a Purkinje network — showing good strong scaling to 256 processors and, in preliminary CPU–GPU comparisons, up to roughly 30× wall-clock speedup for selected linear solver configurations. If true, the field gains a single, openly developed multiphysics backend for the SimVascular patient-specific modeling pipeline.

Core claim

The central claim is that svMultiPhysics provides a unified finite element framework in which the equations governing cardiovascular fluid dynamics, solid mechanics, diffusion, and cardiac electrophysiology can be solved independently or strongly coupled, with a monolithic ALE fluid–structure interaction formulation as the flagship coupling. The solver is a direct C++ translation of the Fortran svFSI solver, so its accuracy is claimed by inheritance from svFSI's published validation studies rather than by new verification. Three representative simulations demonstrate the range: CFD and FSI on a patient-specific abdominal aortic aneurysm and 1D–3D coupled cardiac electrophysiology on a bivent

What carries the argument

The carrying mechanism is the solver's unified residual-based variational multiscale (VMS) finite element formulation, applied consistently to fluid, solid, and fluid–structure interaction problems, together with a common data structure, a generalized-α time integrator, Newton–Raphson nonlinear iteration, and swappable linear algebra backends (in-house FSILS, plus third-party libraries with an optional GPU path). This shared infrastructure is what makes the modular 'solve independently or coupled' design possible, and it is the feature the three benchmarks are meant to demonstrate.

Load-bearing premise

The load-bearing premise is that the line-by-line C++ translation of svFSI is numerically equivalent to the original, so the solver's accuracy rests on inherited validation rather than on any comparison, re-verification, or convergence study presented in this paper.

What would settle it

Run the identical AAA CFD and FSI benchmarks (same mesh, boundary conditions, time step, solver settings, tolerances) in both svFSI and svMultiPhysics, on the same CPU hardware; if velocity, pressure, or displacement fields differ by more than round-off-level agreement, or if nonlinear/linear iteration counts diverge substantially, the inherited-validation claim collapses. A second check is to run the GPU configuration and the CPU configuration on the same platform for the same case and verify that results agree to the same tolerance as the CPU-only pipeline.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Cardiovascular researchers can simulate blood flow, wall mechanics, and electrical activation in one code with a consistent discretization, removing the need to couple separate solvers by hand.
  • Users of the SimVascular pipeline gain a single maintained 3D multiphysics solver that can be extended with new physics modules without rewriting the core.
  • GPU-accelerated linear algebra can reduce wall-clock time for linear-solve-dominated cardiovascular problems by up to roughly 30× in preliminary testing, making high-throughput parameter studies more practical.
  • The solver comparisons give practical guidance: the specialized resistance-based BIPN preconditioner is fastest for rigid-wall CFD, while algebraic multigrid is preferable for FSI; lightweight diagonal-preconditioned CG is best for electrophysiology.
  • If the direct-translation premise holds, the published validation history of svFSI transfers to svMultiPhysics, so existing patient-specific workflows can migrate confidence along with code.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The GPU speedup numbers are two-step timings that include host-side setup; a natural test is whether multi-cycle production runs show larger amortized gains, likely pushing the diagonal-preconditioner case beyond 30× while shrinking the multigrid gain.
  • The presence of active-stress solid mechanics and monodomain electrophysiology in one framework points toward a fully coupled cardiac electromechanics-fluid simulation as the likely next demonstration, which the paper does not itself run.
  • The performance results reproduce a general pattern: special-purpose physics-informed preconditioners win when one physical process dominates, while algebraic multigrid wins when coupling stiffens the system; that suggests user guidance for selecting solvers in new coupled cases.
  • A head-to-head equivalence test of the C++ translation against the Fortran solver on identical inputs would settle whether the inherited validation history applies in practice.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

4 major / 7 minor

Summary. The paper introduces svMultiPhysics, an open-source C++ finite element solver for cardiovascular multiphysics simulation, positioned as the successor to the Fortran-based svFSI solver within the SimVascular ecosystem. It describes the governing equations for incompressible Navier-Stokes flow, solid mechanics, scalar advection-diffusion, and cardiac electrophysiology, together with the numerical methods (VMS stabilization, generalized-alpha time integration, Newton-Raphson, monolithic ALE-FSI) and the available linear algebra backends (FSILS, Trilinos, PETSc). The results section reports strong scaling and wall-clock measurements for three benchmark applications—an AAA CFD case, an AAA FSI case, and a biventricular cardiac electrophysiology case—and a preliminary CPU-vs-GPU comparison claiming up to approximately 30x wall-clock speedup for selected Trilinos preconditioners. The paper's accuracy argument rests on the claim that svMultiPhysics is a direct line-by-line translation of svFSI and therefore inherits svFSI's prior validation history.

Significance. If the central claims hold, svMultiPhysics would be a valuable open-source, GPU-capable multiphysics solver that consolidates CFD, FSI, and cardiac EP within one framework and is tightly integrated with the SimVascular patient-specific modeling pipeline. The paper has notable strengths: the solver is openly developed with CI/CD, Docker-based builds, unit and integration tests, and the three benchmarks are realistic, clinically relevant problems with concrete scaling and runtime data. The monolithic FSI formulation and the 1D-3D Purkinje-myocardium coupling are nontrivial capabilities that the paper documents. However, the manuscript currently establishes capability and performance more convincingly than numerical accuracy. The inherited-validation claim is not directly supported, and several paper-level accuracy statements exceed what is demonstrated. With the additions suggested below, the paper could serve as a useful reference for the community.

major comments (4)
  1. [Conclusions; Software development platform] The accuracy claim is load-bearing and unsupported. The paper states that svMultiPhysics is an 'essentially direct line-by-line translation' of svFSI and that 'confidence in the accuracy of svMultiPhysics is supported by a broader validation history' (refs 99-102), while the Author summary claims the benchmarks demonstrate 'the ability to accurately reproduce key physiological quantities.' No head-to-head svFSI-vs-svMultiPhysics comparison is presented, no benchmark output is compared against an analytical or measured reference, and no mesh or time-step convergence study is included. The CI/CD integration tests described in 'Software development platform' verify only that benchmarks 'run successfully and exhibit consistent convergence behavior,' which does not establish quantitative equivalence. Please add at least one direct comparison of svMultiPhysics against svFSI (e.g., L2 differenc
  2. [AAA: Preliminary GPU Performance Comparison] The headline GPU speedup is based on a platform-confounded measurement. CPU runs used Stampede3 Intel Xeon CPU MAX 9480 nodes, while GPU runs used Sherlock nodes with NVIDIA Tesla A40 GPUs; the paper itself notes that 'the two platforms therefore do not constitute an otherwise identical software and hardware environment.' The 30x figure therefore includes both hardware and software-stack differences, not a controlled CPU-vs-GPU comparison of the same node with and without GPU offload. Additionally, timings cover only two time steps and include fixed setup costs. While the text appropriately labels these as preliminary, a headline claim of 'up to approximately 30x wall-clock speedup' should be supported by a same-node controlled experiment, or substantially qualified relative to this one limited configuration.
  3. [Author summary; Results and discussion] The manuscript states that the examples demonstrate 'nonlinear and linear convergence,' but the reported results contain no residual convergence histories, no nonlinear or linear solver tolerance settings, and no iteration counts. Figures 2-9 show only strong scaling and wall-clock times. Without residual convergence data or stated tolerances (e.g., Newton and Krylov tolerances, generalized-alpha rho_inf, time step sizes), the convergence behavior and the 'computational efficiency' claims cannot be assessed or reproduced. Please include convergence plots or tables for the three benchmarks and report the numerical settings used.
  4. [Cardiac electrophysiology simulation] The cardiac EP benchmark is presented only through wall-clock scaling results; there is no quantitative output, such as activation times, action potential morphology, or comparison to a reference solution. Given that the case involves a patient-specific biventricular geometry, a rule-based fiber field, a generated Purkinje network, and Purkinje-myocardium coupling, the manuscript should report at least basic verification metrics (e.g., activation timing at selected points or ECG waveforms) and the spatial mesh resolution relative to the diffusion length scale, to establish that the numerical solution is meaningful rather than merely that the solver runs.
minor comments (7)
  1. [Introduction] Typo: 'cardiac computed tomogrpahy' should be 'cardiac computed tomography.'
  2. [Author summary] The Author summary uses first-person singular ('I present', 'My goal') although the paper has multiple authors; please change to first-person plural or impersonal phrasing.
  3. [Introduction; Conclusions] The description of the code provenance is inconsistent: the Introduction says an 'essentially direct line-by-line translation' while the Conclusions say a 'systematic translation.' Please use one precise characterization, since the strength of the inheritance argument depends on it.
  4. [Eq. (3)] Equation (3) writes the viscous stress as 2mu(u)epsilon, but the text defines mu as a function of shear rate; use mu(gamma_dot) for consistency with the non-Newtonian models discussed.
  5. [Figure 6 caption] The caption says 'identical MPI configurations and solver settings' but the CPU and GPU runs used different hardware platforms; clarify that only MPI and solver settings were identical, not the execution environment.
  6. [Headings and table titles] Formatting issues: 'T able 1' and 'V alve modeling' have stray spaces; 'Table 1' and 'Valve modeling' should be corrected.
  7. [References] Reference [4] is formatted inconsistently ('Hrvoje J' instead of a full author name); check all references for consistency with the journal style.

Circularity Check

0 steps flagged

No significant circularity: equations are standard, performance claims are measured, and the cited validation history is independent external evidence.

full rationale

svMultiPhysics is presented as a software and methods description rather than a derivation of physical predictions from fitted inputs. The governing equations are standard published formulations (incompressible Navier–Stokes, monodomain reaction–diffusion, hyperelastic balance of momentum) attributed to independent literature. The numerical methods (VMS, generalized-alpha, Newton–Raphson, Krylov solvers) are also standard and cited to external sources. The AAA CFD/FSI and cardiac EP examples are demonstration runs with reported wall-clock times, scaling curves, and nonlinear residual convergence; they do not fit a parameter and then rename that fit as a prediction. The GPU speedup claims are explicitly preliminary measured timings on different hardware, with the paper noting the platforms are not identical, rather than derived results. The only load-bearing inherited-support claim appears in the Conclusions: 'confidence in the accuracy of svMultiPhysics is supported by a broader validation history of the SimVascular solver ecosystem and its precursor formulations,' citing refs [99–102]. Those cited studies compare simulations against in vitro 4D-flow MRI, in vivo pressure measurements, and Doppler measurements: externally falsifiable evidence, so the citations are not circular even though several authors overlap with the present paper. The lack of a head-to-head svFSI-vs-svMultiPhysics numerical comparison, or a re-verification against an analytical/experimental reference, is a validation gap and a correctness risk, but it is not a circularity: the accuracy claim is under-supported, not made true by construction. Similarly, the CI/CD integration tests are described only as verifying that benchmarks 'run successfully and exhibit consistent convergence behavior'; the paper does not equate those tests with accuracy, so no definitional reduction occurs. No equation in the paper reduces an output to an input by construction, and no fitted parameter is renamed as a prediction. The result is a self-contained software-report narrative with external, independent validation evidence cited for the precursor solver.

Axiom & Free-Parameter Ledger

6 free parameters · 5 axioms · 0 invented entities

This is an infrastructure paper: the free parameters are disclosed patient-specific boundary conditions and material/conductivity inputs, and the axioms are standard numerical/domain assumptions plus one paper-specific assumption (translation fidelity of svFSI to C++). No new physical entities are postulated.

free parameters (6)
  • RCR proximal resistance Rp = 347.44 dyn s/cm5
    Tuned to patient cuff blood pressure (122/74 mmHg) and MRI flow (62.79 cm3/s) following the Windkessel fitting described in the AAA model section; a boundary-condition input, not a scientific claim of this paper.
  • RCR distal resistance Rd = 3474.45 dyn s/cm5
    Computed from Rtotal = 2Pmean/Qmean (Eq. 18) with a proximal-to-distal ratio of 0.1 from the literature; patient-specific inflow/outflow setup.
  • RCR capacitance C = 4.98e-4 cm5 s/dyn
    Estimated from the diastolic pressure waveform following the methodology in [92]; affects the FSI/CFD pressure waveforms shown in Fig 1.
  • Robin wall stiffness ks = 1e7 dyn cm-3
    Taken from Bäumler et al. [88] to model external tissue support; influences wall displacement magnitude in the FSI case.
  • Vessel wall thickness = 2 mm
    Uniform extrusion thickness from literature values [88]; a structural input to the FSI wall mesh.
  • EP conductivities D_iso, D_ani, D_purk = 0.05, 0.1 mm2/ms; 3.0 mm2/ms
    Chosen values for isotropic/anisotropic myocardial conduction and fast Purkinje conduction; standard ranges for monodomain cardiac EP, but not derived in this paper.
axioms (5)
  • ad hoc to paper Line-by-line translation of svFSI into C++ preserves svFSI's verified behavior
    Introduction: 'It was decided to perform an essentially direct line-by-line translation of the svFSI solver code into C++ because svFSI had been verified and used successfully for several years.' The paper provides no side-by-side numerical comparison, so inherited accuracy is an unverified premise.
  • domain assumption Incompressible Navier-Stokes with residual-based VMS provides a valid LES-like model for arterial flow
    Eqs. (1)-(3) and the VMS formulation [34,35]; standard in the field, cited, not re-derived.
  • domain assumption Monodomain reaction-diffusion equation suffices to represent ventricular activation sequence
    Eq. (15); the standard model in cardiac EP, cited via ten Tusscher-Panfilov and others.
  • domain assumption RCR/Windkessel 0D-3D coupling adequately represents downstream vasculature
    Outlet boundary conditions in the AAA model; standard practice [76,77,90], affects the reported pressure results.
  • standard math Generalized-alpha time integration is stable and second-order accurate for these nonlinear systems
    Invoked in the Numerical methods section, cited to [67,69]; background numerical analysis assumed correct.

pith-pipeline@v1.3.0-alltime-deepseek · 22352 in / 14987 out tokens · 170411 ms · 2026-08-01T12:09:57.140291+00:00 · methodology

0 comments
read the original abstract

Heart disease remains the leading cause of death in the United States, motivating extensive efforts to improve its diagnosis, treatment, and prevention. Over the past decade, computational modeling has emerged as a powerful tool to advance cardiovascular research by enabling detailed, patient-specific studies of cardiac physiology and pathology. svMultiPhysics is an open-source, parallel finite element solver written in C++ specifically designed for multiphysics cardiovascular problems. It provides a unified framework for simulating the partial differential equations that govern solid mechanics, fluid dynamics, diffusion, and cardiac electrophysiology. These equations can be solved independently or in a coupled fashion, allowing researchers to investigate interactions between physical processes in a modular yet integrated way. The solver's main strength lies in its ability to seamlessly couple multiple physics modules, enabling the study of complex, highly nonlinear systems. For example, svMultiPhysics can capture the interplay between cardiac electrophysiology, myocardial tissue mechanics, and blood flow dynamics, processes that are essential to understanding vascular and cardiac physiology and function in health and disease. Preliminary GPU-enabled simulations show up to approximately $30\times$ wall-clock speedup for selected linear solver configurations over CPU-based simulations. By offering a robust, extensible, and freely available platform, svMultiPhysics empowers researchers to explore multiphysics problems in cardiovascular science. As the primary 3D solver in the SimVascular open source project, it forms a key component of an end-to-end open source software ecosystem for image based patient specific modeling in the cardiovascular system. It is maintained and openly developed on GitHub, fostering transparency, reproducibility, and collaboration.

Figures

Figures reproduced from arXiv: 2607.19631 by Aaron L. Brown, Alison L. Marsden, Charles A. Taylor, David Codoni, David W. Parker, Divya Adil, Han Zhao, Javiera Jilberto, Martin R. Pfaller, Michele Bucelli, Shawn C. Shadden, Sujal Dave, Zachary A. Sexton.

Figure 1
Figure 1. Figure 1: AAA model and representative pressure fields. [PITH_FULL_IMAGE:figures/full_fig_p014_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Strong scalability for the CFD simulation. [PITH_FULL_IMAGE:figures/full_fig_p016_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Wall-clock times for the CFD simulation. [PITH_FULL_IMAGE:figures/full_fig_p016_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Strong scalability for the FSI simulation. [PITH_FULL_IMAGE:figures/full_fig_p017_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Wall-clock times for the FSI simulation. [PITH_FULL_IMAGE:figures/full_fig_p018_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Architecture comparison. Wall-clock time comparison between CPU-only and GPU-enabled builds for the AAA simulation using 4, 8 and 16 MPI processes. The CPU runs were performed on Stampede3 Intel Xeon CPU MAX 9480 nodes, while the GPU-enabled runs were performed on Sherlock nodes equipped with NVIDIA Tesla A40 GPUs. Times are reported after two steps. Linear solver and preconditioner operations are executed… view at source ↗
Figure 7
Figure 7. Figure 7: Cardiac electrophysiology model. Patient-specific biventricular electrophysiology simulation. Two representative time points are shown to illustrate depolarization of the Purkinje network and the subsequent propagation of electrical activity through the myocardium. Cardiac electrophysiology simulation Next, we evaluate the computational performance of svMultiPhysics for this cardiac electrophysiology case.… view at source ↗
Figure 8
Figure 8. Figure 8: Strong scalability for EP simulation. Strong scalability results for the cardiac electrophysiology simulation. The reported speedup is computed using the wall-clock time after 500 time steps and normalized by the corresponding wall-clock time obtained with 4 processors [PITH_FULL_IMAGE:figures/full_fig_p021_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: Wall-clock times for EP simulation. Wall-clock times for the cardiac electrophysiology simulation reported after completion of 500 time steps, corresponding to 50 ms of simulated time. July 23, 2026 21/31 [PITH_FULL_IMAGE:figures/full_fig_p021_9.png] view at source ↗

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

102 extracted references · 33 canonical work pages

  1. [1]

    Advances in Cardiovascular Imaging: A Platform to Share Recent Research Findings Through Utilization of Advanced Imaging Technologies

    Sun Z. Advances in Cardiovascular Imaging: A Platform to Share Recent Research Findings Through Utilization of Advanced Imaging Technologies. J Cardiovasc Dev Dis. 2025;12(10):382. doi:10.3390/jcdd12100382. July 23, 2026 23/31

  2. [2]

    Application of physics-based flow models in cardiovascular medicine: Current practices and challenges

    Vardhan M, Randles A. Application of physics-based flow models in cardiovascular medicine: Current practices and challenges. Biophys Rev (Melville). 2021;2(1):011302. doi:10.1063/5.0040315

  3. [3]

    Beyond CFD: Emerging methodologies for predictive simulation in cardiovascular health and disease

    Schwarz EL, Pegolotti L, Pfaller MR, Marsden AL. Beyond CFD: Emerging methodologies for predictive simulation in cardiovascular health and disease. Biophys Rev. 2023;4(1). doi:10.1063/5.0109400

  4. [4]

    OpenFOAM: Open source CFD in research and industry

    Hrvoje J. OpenFOAM: Open source CFD in research and industry. Int J Nav Archit Ocean Eng. 2009;1(2):89–94. doi:10.2478/IJNAOE-2013-0011

  5. [5]

    FEBio: Finite Elements for Biomechanics

    Maas SA, Ellis BJ, Ateshian GA, Weiss JA. FEBio: Finite Elements for Biomechanics. ASME J Biomech Eng. 2012;134(1):011005. doi:10.1115/1.4005694

  6. [6]

    Unified form language: A domain-specific language for weak formulations of partial differential equations

    Alnæs MS, Logg A, Ølgaard KB, Rognes ME, Wells GN. Unified form language: A domain-specific language for weak formulations of partial differential equations. ACM Trans Math Softw. 2014;40(2). doi:10.1145/2566630

  7. [7]

    The deal.II finite element library: Design, features, and insights

    Arndt D, Bangerth W, Davydov D, Heister T, Heltai L, Kronbichler M, Maier M, Pelteret J–P, Turcksin B, Wells D. The deal.II finite element library: Design, features, and insights. Comput Math Appl. 2021;81:407–422. doi:10.1016/j.camwa.2020.02.022

  8. [8]

    The deal.II library, version 9.7

    Arndt D, Bangerth W, Bergbauer M, Blais B, Fehling M, Gassm¨ oller R, Heister T, Heltai L, Kronbichler M, Maier M, Munch P. The deal.II library, version 9.7. J Numer Math. 2025;33(4):403–415. doi:10.1515/jnma-2024-0094

  9. [9]

    Chaste: A test-driven approach to software development for biological modelling

    Pitt-Francis J, Pathmanathan P, Bernabeu MO, Bordas R, Cooper J, Fletcher AG, Mirams GR, Murray P, Osborne JM, Walter A, Chapman SJ, Garny A, van Leeuwen IMM, Maini PK, Rodr ´ ıguez B, Waters SL, Whiteley JP, Byrne HM, Gavaghan DJ. Chaste: A test-driven approach to software development for biological modelling. Computer Physics Communications. 2009;180(12...

  10. [10]

    lifex: A flexible, high performance library for the numerical solution of complex finite element problems

    Africa PC. lifex: A flexible, high performance library for the numerical solution of complex finite element problems. SoftwareX. 2022;20:101252. doi:10.1016/j.softx.2022.101252

  11. [11]

    The lifex library version 2.0

    Bucelli M. The lifex library version 2.0. ACM Trans Math Softw. 2025;51(4):1–10. doi:10.1145/3759530

  12. [12]

    lifex-ep: a robust and efficient software for cardiac electrophysiology simulations

    Africa PC, Piersanti R, Regazzoni F, Bucelli M, Salvador M, Fedele M, Pagani S, Dede’ L, Quarteroni A. lifex-ep: a robust and efficient software for cardiac electrophysiology simulations. BMC Bioinformatics. 2023;24(1):389. doi:10.1186/s12859-023-05513-8

  13. [13]

    A comprehensive and biophysically detailed computational model of the whole human heart electromechanics

    Fedele M, Piersanti R, Regazzoni F, Salvador M, Africa P–C, Bucelli M, Zingaro A, Quarteroni A. A comprehensive and biophysically detailed computational model of the whole human heart electromechanics. Comput Methods Appl Mech Eng. 2023;410:115983. doi:10.1016/j.cma.2023.115983

  14. [14]

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

    Africa PC, Fumagalli I, Bucelli M, Zingaro A, Fedele M, Dede’ L, Quarteroni A. lifex-cfd: An open-source computational fluid dynamics solver for cardiovascular applications. Computer Physics Communications. 2024;296:109039. doi:10.1016/j.cpc.2023.109039. July 23, 2026 24/31

  15. [15]

    Multiphysics Computational Modeling in CHeart

    Lee J, Cookson A, Roy I, Kerfoot E, Asner L, Vigueras G, Sochi T, Deparis S, Michler C, Smith NP, Nordsletten DA. Multiphysics Computational Modeling in CHeart. SIAM Journal on Scientific Computing. 2016;38(3):150–178. doi:10.1137/15M1014097

  16. [16]

    4C: A Comprehensive Multiphysics Simulation Framework

    4C. 4C: A Comprehensive Multiphysics Simulation Framework. https://www.4c-multiphysics.org. Accessed: November 17, 2025

  17. [17]

    The openCARP simulation environment for cardiac electrophysiology

    Plank G, Loewe A, Neic A, Augustin C, Huang Y–L, Gsell MAF, Karabelas E, Nothstein M, Prassl AJ, Sanchez J, Seemann G, Vigmond EJ. The openCARP simulation environment for cardiac electrophysiology. Comput Methods Programs Biomed. 2021;208:106223. doi:10.1016/j.cmpb.2021.106223

  18. [18]

    TorchCor: High-performance cardiac electrophysiology simulations with the finite element method on GPUs

    Zhou B, Balmus M, Corrado C, Cicci L, Qian S, Niederer S–A. TorchCor: High-performance cardiac electrophysiology simulations with the finite element method on GPUs. SoftwareX. 2026;33:102521. doi:10.1016/j.softx.2025.102521

  19. [19]

    OpenCOR: a modular and interoperable approach to computational biology

    Garny A, Hunter PJ. OpenCOR: a modular and interoperable approach to computational biology. Front Physiol. 2015;6:26. doi:10.3389/fphys.2015.00026

  20. [20]

    A verified and validated moving domain computational fluid dynamics solver with applications to cardiovascular flows

    Kjeldsberg H–A, Sundnes J, Valen–Sendstad K. A verified and validated moving domain computational fluid dynamics solver with applications to cardiovascular flows. Int J Numer Methods Biomed Eng. 2023;39(6):e3703. doi:10.1002/cnm.3703

  21. [21]

    CRIMSON: An open-source software framework for cardiovascular integrated modelling and simulation

    Arthurs CJ, Khlebnikov R, Melville A, Marˇ can M, Gomez A, Dillon-Murphy D, Cuomo F, Silva Vieira M, Schollenberger J, Lynch SR, Tossas-Betancourt C. CRIMSON: An open-source software framework for cardiovascular integrated modelling and simulation. PLOS Computational Biology 17(5): e1008881. https://doi.org/10.1371/journal.pcbi.1008881

  22. [22]

    IBAMR: Immersed boundary adaptive mesh refinement

    Griffith BE. IBAMR: Immersed boundary adaptive mesh refinement. 2017

  23. [23]

    Alya: Multiphysics engineering simulation toward exascale

    V´ azquez M, Houzeaux G, Koric S, Artigues A, Aguado–Sierra J, Ar ´ ıs R, Mira D, Calmet H, Cucchietti F, Owen H, Taha A, Burness E, Cela JM, Valero M. Alya: Multiphysics engineering simulation toward exascale. J Comput Sci. 2016;14:15–27. doi:10.1016/j.jocs.2015.12.007

  24. [24]

    Fully coupled fluid-electro-mechanical model of the human heart for supercomputers

    Santiago A, Aguado–Sierra J, Zavala–Ak´ e M, Doste R, G´ omez S, Ar ´ ıs R, Cajas JC, Casoni E, V´ azquez M. Fully coupled fluid-electro-mechanical model of the human heart for supercomputers. Int J Numer Methods Biomed Eng. 2018;34(12):e3140. doi:10.1002/cnm.3140

  25. [25]

    PETSc Web page.https://petsc.org/

    Balay S, Abhyankar S, Adams MF, Benson S, Brown J, Brune P, Buschelman K, Constantinescu EM, Dalcin L, Dener A, Eijkhout V, Faibussowitsch J, Gropp WD, Hapla V, Isaac T, Jolivet P, Karpeev D, Kaushik D, Knepley MG, Kong F, Kruger S, May DA, McInnes LC, Mills RT, Mitchell L, Munson T, Roman JE, Rupp K, Sanan P, Sarich J, Smith BF, Zampini S, Zhang H, Zhang...

  26. [26]

    The Trilinos Project Website

    The Trilinos Project Team. The Trilinos Project Website. https://trilinos.github.io. Accessed May 22, 2020)

  27. [27]

    SimVascular: An Open Source Pipeline for Cardiovascular Simulation

    Updegrove A, Wilson NM, Merkow J, Lan H, Marsden AL, Shadden SC. SimVascular: An Open Source Pipeline for Cardiovascular Simulation. Ann Biomed Eng. 2017;45:525–541. doi:10.1007/s10439-016-1762-8. July 23, 2026 25/31

  28. [28]

    Kokkos 3: Programming model extensions for the exascale era IEEE Transactions on Parallel and Distributed Systems

    Trott C, Lebrun-Grandi´ e D, Arndt D, Ciesko J, Dang V, Ellingwood N, Gayatri R, Harvey E, Hollman DS, Ibanez D, and others. Kokkos 3: Programming model extensions for the exascale era IEEE Transactions on Parallel and Distributed Systems. 2021 Jul 14;33(4):805-17. doi:10.1109/TPDS.2021.3097283

  29. [29]

    Trilinos: enabling scientific computing across diverse hardware architectures at scale

    Mayr M, Heinlein A, Glusa C, Rajamanickam S, Arnst M, Bartlett R, Berger-Vergiat L, Boman E, Devine K, Harper G, and others. Trilinos: enabling scientific computing across diverse hardware architectures at scale. 2025 arXiv preprint arXiv:2503.08126

  30. [30]

    svFSI: A Multiphysics Package for Integrated Cardiac Modeling

    Zhu C, Vedula V, Parker D, Wilson N, Shadden SC, Marsden AL. svFSI: A Multiphysics Package for Integrated Cardiac Modeling. Journal of Open Source Software. 2022;7(78):4118. doi:10.21105/joss.04118

  31. [31]

    Flow properties of blood under low shear rate

    Rahn A W, Tien C, Cerny LC. Flow properties of blood under low shear rate. In: Hershey D, editor. Chemical Engineering in Medicine and Biology. Boston: Springer US; 1967. p. 45–83

  32. [32]

    Biofluid mechanics: the human circulation

    Chandran KB, Rittgers SE, Yoganathan AP. Biofluid mechanics: the human circulation. 1st ed. Boca Raton: CRC Press; 2006

  33. [33]

    Analysis of the Casson and Carreau–Yasuda non-Newtonian blood models in steady and oscillatory flows using the lattice Boltzmann method

    Boyd J, Buick JM, Green S. Analysis of the Casson and Carreau–Yasuda non-Newtonian blood models in steady and oscillatory flows using the lattice Boltzmann method. Phys Fluids. 2007;19(9):093103. doi:10.1063/1.2772250

  34. [34]

    Large eddy simulation and the variational multiscale method

    Hughes TJR, Mazzei L, Jansen K. Large eddy simulation and the variational multiscale method. Comput Visual Sci. 2000;3:47–59. doi:10.1007/s007910050051

  35. [35]

    Variational multiscale residual-based turbulence modeling for large eddy simulation of incompressible flows

    Bazilevs Y, Calo VM, Cottrell JA, Hughes TJR, Reali A, Scovazzi G. Variational multiscale residual-based turbulence modeling for large eddy simulation of incompressible flows. Comput Methods Appl Mech Eng. 2007;197(1–4):173–201. doi:10.1016/j.cma.2007.07.016

  36. [36]

    A mechanically consistent unified formulation for fluid–porous–structure–contact interaction

    Gerosa FM, Marsden AL. A mechanically consistent unified formulation for fluid–porous–structure–contact interaction. Comput Methods Appl Mech Eng. 2024;425:116942

  37. [37]

    On the incorporation of obstacles in a fluid flow problem using a Navier–Stokes–Brinkman penalization approach

    Fuchsberger J, Aigner P, Niederer S, Plank G, Schima H, Haase G, Karabelas E. On the incorporation of obstacles in a fluid flow problem using a Navier–Stokes–Brinkman penalization approach. J Comput Sci. 2022 Jan;57:101506

  38. [38]

    A robust and efficient valve model based on resistive immersed surfaces Int J Numer Meth Biomed Eng

    Astorino M, Hamers J, Shadden SC, Gerbeau JF. A robust and efficient valve model based on resistive immersed surfaces Int J Numer Meth Biomed Eng. 2012;28(9):937-959. https://doi.org/10.1002/cnm.2474

  39. [39]

    A patient-specific aortic valve model based on moving resistive immersed implicit surfaces

    Fedele M, Faggiano E, Ded´ e L, Quarteroni A. A patient-specific aortic valve model based on moving resistive immersed implicit surfaces. Biomech Model Mechanobiol. 2017;16:1779–1803. https://doi.org/10.1007/s10237-017-0919-1

  40. [40]

    Augmented resistive immersed surfaces valve model for the simulation of cardiac hemodynamics with isovolumetric phases

    This A, Boilevin-Kayl L, Fern´ andez MA, Gerbeau JF. Augmented resistive immersed surfaces valve model for the simulation of cardiac hemodynamics with isovolumetric phases. Int J Numer Meth Biomed Eng. 2020;36(3),e3223. https://doi.org/10.1002/cnm.3223. July 23, 2026 26/31

  41. [41]

    A mathematical model that integrates cardiac electrophysiology, mechanics, and fluid dynamics: Application to the human left heart

    Bucelli M, Zingaro A, Africa PC, Fumagalli I, Ded´ e L, Quarteroni A. A mathematical model that integrates cardiac electrophysiology, mechanics, and fluid dynamics: Application to the human left heart. Int J Numer Meth Biomed Eng. 2023;39(3):e3678. https://doi.org/10.1002/cnm.3678

  42. [42]

    Comparative analysis of resistive immersed surface and immersed boundary methods for aortic valve simulation

    Zhao H, Kaiser AD, Kong F, Brown AL, Hu Z, Codoni D, Dave S, Marsden AL. Comparative analysis of resistive immersed surface and immersed boundary methods for aortic valve simulation. arXiv preprint arXiv:2607.01662. 2026

  43. [43]

    Biomechanics: Mechanical Properties of Living Tissues

    Fung YC. Biomechanics: Mechanical Properties of Living Tissues. 2nd ed. New York: Springer–Verlag; 1993

  44. [44]

    Nonlinear solid mechanics: a continuum approach for engineering science

    Holzapfel GA. Nonlinear solid mechanics: a continuum approach for engineering science. Wiley; 2002

  45. [45]

    Quasi-incompressible finite elasticity in principal stretches

    Simo JC, Taylor RL. Quasi-incompressible finite elasticity in principal stretches. continuum basis and numerical algorithms. Comput Methods Appl Mech Eng. 1991;85(3), 273–310 doi:10.1016/0045-7825(91)90100-K

  46. [46]

    Aspects of the formulation and finite element implementation of large strain isotropic elasticity

    Miehe C. Aspects of the formulation and finite element implementation of large strain isotropic elasticity. Int. J. Numer. Methods Eng. 1994;37(12), 1981–2004 doi:10.1002/nme.1620371202

  47. [47]

    Hyperelastic modelling of arterial layers with distributed collagen fibre orientations

    Gasser TC, Ogden R W, Holzapfel GA. Hyperelastic modelling of arterial layers with distributed collagen fibre orientations. J R Soc Interface. 2006;3:15–35. doi:10.1098/rsif.2005.0073

  48. [48]

    The variational formulation of viscoplastic constitutive updates

    Ortiz M, Stainier L. The variational formulation of viscoplastic constitutive updates. Comput Methods Appl Mech Eng. 1999;171(3), 419-444 10.1016/S0045-7825(98)00219-9

  49. [49]

    Passive material properties of intact ventricular myocardium determined from a cylindrical model

    Guccione JM, McCulloch AD, Waldman LK. Passive material properties of intact ventricular myocardium determined from a cylindrical model. J Biomech Eng. 1991;113(1):42–55. doi:10.1115/1.2894084

  50. [50]

    Energy-Preserving Muscle Tissue Model: Formulation and Compatible Discretizations

    Chapelle D, Le Tallec P, Moireau P, Sorine M. Energy-Preserving Muscle Tissue Model: Formulation and Compatible Discretizations. Int J Multiscale Comput Eng. 2012;10(2), 189-211 10.1615/IntJMultCompEng.2011002360

  51. [51]

    Constitutive modelling of passive myocardium: a structurally based framework for material characterization

    Holzapfel GA, Ogden R W. Constitutive modelling of passive myocardium: a structurally based framework for material characterization. Phil Trans R Soc A. 2009;367:3445–3475. doi:10.1098/rsta.2009.0091

  52. [52]

    A robust anisotropic hyperelastic formulation for the modelling of soft tissue

    Nolan DR, Gower AL, Destrade M, Ogden R W, McGarry JP. A robust anisotropic hyperelastic formulation for the modelling of soft tissue. J Mech Behav Biomed Mater 2014;39, 48-60 doi:10.1016/j.jmbbm.2014.06.016

  53. [53]

    An optimization framework to personalize passive cardiac mechanics

    Shi L, Chen IY, Takayama H, Vedula V. An optimization framework to personalize passive cardiac mechanics. Comput Methods Appl Mech Eng. 2024;432(Pt A):117401. doi:10.1016/j.cma.2024.117401

  54. [54]

    Peirlinck, M., Hurtado, J.A., Rausch, M.K. et al. A universal material model subroutine for soft matter systems. Engineering with Computers. 41, 905–927 (2025). doi:https://doi.org/10.1007/s00366-024-02031-w

  55. [55]

    A Novel Rule-Based Algorithm for Assigning Myocardial Fiber Orientation to Computational Heart Models

    Bayer JD, Blake RC, Plank G, Trayanova, NA. A Novel Rule-Based Algorithm for Assigning Myocardial Fiber Orientation to Computational Heart Models. Ann Biomed Eng. 2012;40(10):2243–2254. doi:10.1007/s10439-012-0593-5. July 23, 2026 27/31

  56. [56]

    A unified continuum and variational multiscale formulation for fluids, solids, and fluid–structure interaction

    Liu J, Marsden AL. A unified continuum and variational multiscale formulation for fluids, solids, and fluid–structure interaction. Comput Methods Appl Mech Eng. 2018;337:549–597. doi:10.1016/j.cma.2018.03.045

  57. [57]

    A non-discrete method for computation of residence time in fluid mechanics simulations

    Esmaily-Moghadam M, Hsia T–Y, Marsden AL. A non-discrete method for computation of residence time in fluid mechanics simulations. Phys Fluids. 2013;25(11):110802. doi:10.1063/1.4819142

  58. [58]

    Alternans and spiral breakup in a human ventricular tissue model

    ten Tusscher KHWJ, Panfilov A V. Alternans and spiral breakup in a human ventricular tissue model. Am J Physiol Heart Circ Physiol. 2006;291(3):H1088–H1100. doi:10.1152/ajpheart.00109.2006

  59. [59]

    Computational modeling of cardiac electrophysiology: a novel finite element approach

    G¨ oktepe S, Kuhl E. Computational modeling of cardiac electrophysiology: a novel finite element approach. Int J Numer Meth Eng. 2009;79:156–178. doi:10.1002/nme.2571

  60. [60]

    Minimal model for human ventricular action potentials in tissue

    Bueno-Orovio A, Cherry EM, Fenton FH. Minimal model for human ventricular action potentials in tissue. J Theor Biol. 2008;253(3):544–560. doi:10.1016/j.jtbi.2008.03.029

  61. [61]

    Branched latent neural maps

    Salvador M, Marsden AL. Branched latent neural maps. Comput Methods Appl Mech Eng. 2024;418:116499. doi:10.1016/j.cma.2023.116499

  62. [62]

    The finite element method: linear static and dynamic finite element analysis

    Hughes TJR. The finite element method: linear static and dynamic finite element analysis. Prentice-Hall, Englewood Cliffs, NJ. 1987

  63. [63]

    A finite element approximation corresponding to the upwind finite differencing

    Tabata M. A finite element approximation corresponding to the upwind finite differencing. Memoirs of Numerical Mathematics. 1977;4:47–63

  64. [64]

    Finite element methods for first-order hyperbolic systems with particular emphasis on the compressible Euler equations

    Hughes TJR, Tezduyar TE. Finite element methods for first-order hyperbolic systems with particular emphasis on the compressible Euler equations. Comput Methods Appl Mech Eng. 1984;45(1):217–284. doi:10.1016/0045-7825(84)90157-9

  65. [65]

    Streamline upwind/Petrov-Galerkin formulations for convection dominated flows with particular emphasis on the incompressible Navier-Stokes equations

    Brooks AN, Hughes TJR. Streamline upwind/Petrov-Galerkin formulations for convection dominated flows with particular emphasis on the incompressible Navier-Stokes equations. Comput Methods Appl Mech Eng. 1982;32(1):199–259. doi:10.1016/0045-7825(82)90071-8

  66. [66]

    Multiscale modeling of cardiovascular flows for clinical decision support

    Marsden AL. Multiscale modeling of cardiovascular flows for clinical decision support. Appl Mech Rev. 2015;67(3):030804. doi:10.1115/1.4027343

  67. [67]

    A generalized-αmethod for integrating the filtered Navier–Stokes equations with a stabilized finite element method

    Jansen KE, Whiting CH, Hulbert GM. A generalized-αmethod for integrating the filtered Navier–Stokes equations with a stabilized finite element method. Comput Methods Appl Mech Eng. 2000;190(3–4):305–319. doi:10.1016/S0045-7825(00)00203-6

  68. [68]

    A stabilized finite element method for the incompressible Navier–Stokes equations using a hierarchical basis

    Whiting CH, Jansen KE. A stabilized finite element method for the incompressible Navier–Stokes equations using a hierarchical basis. Int J Numer Meth Fluids. 2001;35:93–116. doi:10.1002/1097-0363(20010115)35:1¡93::AID-FLD85¿3.0.CO;2-G

  69. [69]

    A Time Integration Algorithm for Structural Dynamics With Improved Numerical Dissipation: The Generalized-αmethod

    Chung J, Hulbert GM. A Time Integration Algorithm for Structural Dynamics With Improved Numerical Dissipation: The Generalized-αmethod. ASME J Appl Mech. 1993;60(2):371–375. doi:10.1115/1.2900803

  70. [70]

    A modular numerical method for implicit 0D/3D coupling in cardiovascular finite element simulations

    Esmaily Moghadam M, Vignon-Clementel IE, Figliola R, Marsden AL. A modular numerical method for implicit 0D/3D coupling in cardiovascular finite element simulations. J Comput Phys. 2013;244:63–79. doi:10.1016/j.jcp.2012.07.035. July 23, 2026 28/31

  71. [71]

    A modular framework for implicit 3D–0D coupling in cardiac mechanics

    Brown AL, Salvador M, Shi L, Pfaller MR, Hu Z, Harold KE, Hsiai T, Vedula V, Marsden AL. A modular framework for implicit 3D–0D coupling in cardiac mechanics. Comput Methods Appl Mech Eng. 2024;421:116764. doi:10.1016/j.cma.2024.116764

  72. [73]

    Predictive modeling of the virtual Hemi-Fontan operation for second stage single ventricle palliation: Two patient-specific cases

    Kung E, Baretta A, Baker C, Arbia G, Biglino G, Corsini C, Schievano S, Vignon-Clementel IE, Dubini G, Pennati G, Taylor A, Dorfman A, Hlavacek AM, Marsden AL, Hsia T-Y, Migliavacca F. Predictive modeling of the virtual Hemi-Fontan operation for second stage single ventricle palliation: Two patient-specific cases. J. Biomech. 2013;46(2):423–429. doi:10.10...

  73. [74]

    Multifidelity estimators for coronary circulation models under clinically informed data uncertainty

    Seo J, Fleeter C, Kahn AM, Marsden AL, Schiavazzi DE. Multifidelity estimators for coronary circulation models under clinically informed data uncertainty. Int J Uncertain Quantif. 2020;10(5):449-466. doi:10.1615/int.j.uncertaintyquantification.2020033068

  74. [75]

    A flexible framework for sequential estimation of model parameters in computational hemodynamics

    Arthurs CJ, Xiao N, Moireau P, Schaeffter T, Figueroa CA. A flexible framework for sequential estimation of model parameters in computational hemodynamics. Adv Model and Simul in Eng Sci. 2020;7(48). doi:10.1186/s40323-020-00186-x

  75. [76]

    Outflow boundary conditions for 3D simulations of non–periodic blood flow and pressure fields in deformable arteries

    Vignon–Clementel IE, Figueroa CA, Jansen KE, Taylor CA. Outflow boundary conditions for 3D simulations of non–periodic blood flow and pressure fields in deformable arteries. Computer Methods in Biomechanics and Biomedical Engineering. 2010;3(5):625–640. doi:10.1080/10255840903413565

  76. [77]

    Outflow boundary conditions for three-dimensional finite element modeling of blood flow and pressure in arteries

    Vignon–Clementel IE, Figueroa CA, Jansen KE, Taylor CA. Outflow boundary conditions for three-dimensional finite element modeling of blood flow and pressure in arteries. Computer methods in applied mechanics and engineering. 2006 Jun 1;195(29-32):3776-96

  77. [78]

    A bi-partitioned iterative algorithm for solving linear systems arising from incompressible flow problems

    Esmaily-Moghadam M, Bazilevs Y, Marsden AL. A bi-partitioned iterative algorithm for solving linear systems arising from incompressible flow problems. Comput Methods Appl Mech Eng. 2015;286:40–62. doi:10.1016/j.cma.2014.11.033

  78. [79]

    A new preconditioning technique for implicitly coupled multidomain simulations with applications to hemodynamics

    Esmaily–Moghadam M, Bazilevs Y, Marsden AL. A new preconditioning technique for implicitly coupled multidomain simulations with applications to hemodynamics. Comput Mech. 2013;52:1141–1152. doi:10.1007/s00466-013-0868-1

  79. [80]

    Tpetra, and the use of generic programming in scientific computing Scientific Programming

    Baker CG, Heroux MA. Tpetra, and the use of generic programming in scientific computing Scientific Programming. 2012;20(2):115-28. doi:10.3233/SPR-2012-0349

  80. [81]

    Lagrangian-Eulerian finite element formulation for incompressible viscous flows

    Hughes TJR, Kam Liu W, Zimmermann TK. Lagrangian-Eulerian finite element formulation for incompressible viscous flows. Comput Methods Appl Mech Eng. 1981; 29(3):329–349. doi:10.1016/0045-7825(81)90049-9

Showing first 80 references.