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1. Veno-arterial-ECMO in the intensive care unit: From technical aspects to clinical practice

Author: Jean Mantz, Arnaud Follin, Bernard Cholley, Romain Pirracchio, Arthur Le Gall, Nadia Aissaoui, Service d'Anesthésie-Réanimation [CHU HEGP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Service de réanimation médicale [CHU HEGP], École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Assistance publique - Hôpitaux de Paris (AP-HP)-Hôpital Européen Georges Pompidou [APHP] ( HEGP ), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine ( M3DISIM ), Laboratoire de mécanique des solides ( LMS ), École polytechnique ( X ) -MINES ParisTech - École nationale supérieure des mines de Paris-Centre National de la Recherche Scientifique ( CNRS ) -École polytechnique ( X ) -MINES ParisTech - École nationale supérieure des mines de Paris-Centre National de la Recherche Scientifique ( CNRS ) -Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria )
Subjects: medicine.medical_specialty, Critical Care, medicine.medical_treatment, Salvage therapy, Disease, 030204 cardiovascular system & hematology, Critical Care and Intensive Care Medicine, law.invention, 03 medical and health sciences, Extracorporeal Membrane Oxygenation, 0302 clinical medicine, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, law, Multidisciplinary approach, medicine, Extracorporeal membrane oxygenation, Humans, Medical history, Intensive care medicine, business.industry, Cardiogenic shock, Extracorporeal circulation, 030208 emergency & critical care medicine, General Medicine, [ SDV.MHEP.CSC ] Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, medicine.disease, Intensive care unit, 3. Good health, Intensive Care Units, surgical procedures, operative, Anesthesiology and Pain Medicine, business
Abstract: International audience; The use of Veno-Arterial ExtraCorporeal Membrane Oxygenation (VA-ECMO) as a salvage therapy in cardiogenic shock is becoming of current practice. While VA-ECMO is potentially a life-saving technique, results are sometimes mitigated, emphasizing the need for selecting the right indication in the right patient. This relies upon a clear definition of the individual therapeutic project, including the potential for recovery as well as the possible complications associated with VA-ECMO. To maximize the benefits of VA-ECMO, the basics of extracorporeal circulation should be perfectly understood since VA-ECMO can sometimes be detrimental. Hence, to be successful, VA-ECMO should be used by teams with sufficient experience and initiated after a thorough multidisciplinary discussion considering patient’s medical history, pathology as well the anticipated evolution of the disease.
Published: 2018
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2. Solving 2D linear isotropic elastodynamics by means of scalar potentials: a new challenge for finite elements

Author: Patrick Joly, Jerónimo Rodríguez, Sébastien Imperiale, Jorge Martínez, Departamento de Matemática Aplicada, Universidade de Santiago de Compostela [Spain] (USC ), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Université Paris-Saclay, Propagation des Ondes : Étude Mathématique et Simulation (POEMS), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Unité de Mathématiques Appliquées (UMA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS), Universidade de Santiago de Compostela, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine ( M3DISIM ), Laboratoire de mécanique des solides ( LMS ), École polytechnique ( X ) -MINES ParisTech - École nationale supérieure des mines de Paris-Centre National de la Recherche Scientifique ( CNRS ) -École polytechnique ( X ) -MINES ParisTech - École nationale supérieure des mines de Paris-Centre National de la Recherche Scientifique ( CNRS ) -Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ), Propagation des Ondes : Étude Mathématique et Simulation ( POEMS ), Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Unité de Mathématiques Appliquées ( UMA ), École Nationale Supérieure de Techniques Avancées ( Univ. Paris-Saclay, ENSTA ParisTech ) -École Nationale Supérieure de Techniques Avancées ( Univ. Paris-Saclay, ENSTA ParisTech ) -Centre National de la Recherche Scientifique ( CNRS ), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris
Subjects: Numerical Analysis, Applied Mathematics, Isotropy, Scalar (mathematics), Mathematical analysis, General Engineering, 010103 numerical & computational mathematics, [ MATH.MATH-NA ] Mathematics [math]/Numerical Analysis [math.NA], 01 natural sciences, Finite element method, Theoretical Computer Science, 010101 applied mathematics, Computational Mathematics, [ MATH.MATH-AP ] Mathematics [math]/Analysis of PDEs [math.AP], Computational Theory and Mathematics, Displacement field, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Boundary value problem, Time domain, 0101 mathematics, Scalar field, Helmholtz decomposition, Software, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], Mathematics
Abstract: International audience; In this work we present a method for the computation of numerical solutions of 2D homogeneous isotropic elastodynamics equations by solving scalar wave equations. These equations act on the potentials of a Helmholtz decomposition of the displacement field and are decoupled inside the propagation domain. We detail how these equations are coupled at the boundary depending on the nature of the boundary condition satisfied by the displacement field. After presenting the case of rigid boundary conditions, that presents no specific difficulty, we tackle the challenging case of free surface boundary conditions that presents severe stability issues if a straightforward approach is used. We introduce an adequate functional framework as well as a time domain mixed formulation to circumvent these issues. Numerical results confirm the stability of the proposed approach.
Published: 2018
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3. Finite Strain Formulation of the Discrete Equilibrium Gap Principle: I-Mechanically Consistent Regularization for Large Motion Tracking

Author: Genet, Martin, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: Inverse problems, Finite element method, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Motion tracking Mechanical regularization Equilibrium gap principle Finite element method Inverse problems, Mechanical regularization, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph], Motion tracking, Equilibrium gap principle
Abstract: The equilibrium gap principle offers a good trade-off between robustness & accuracy for regularizing motion tracking, as it simply enforces that the tracked motion corresponds to a body deforming under arbitrary loadings. This paper introduces an extension of the equilibrium gap principle in the large deformation setting, a novel regularization term to control surface tractions, both in the context of finite element motion tracking, and an inverse problem consistent reformulation of the tracking problem. Tracking performance of the proposed method, with displacement resolution down to the pixel size, is demonstrated on synthetic images representing various motions with various signal-to-noise ratios.
Published: 2023

4. Essai d'une nouvelle analyse de la mortalité causée par la petite vérole, et des avantages de l'inoculation pour la prévenir

Author: Bernoulli, Daniel, Chapelle, Dominique, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie
Abstract: Mémoires de Mathématique et de Physique, tirés des registres de l'Académie Royale des Sciences de l'année 1760, pages 1-45; Note du transcripteur: Cette transcription se veut parfaitement fidèle à l'original du mémoire (accessible sur le site Gallica de la BNF), ma motivation étant avant tout de rendre celui-ci plus facile d'accès et de lecture, et rendre ainsi hommage à cette oeuvre pionnière, et relativement méconnue parmi toutes les contributions de Daniel Bernoulli. Je me suis donc contenté d'appliquer des modifications mineures liées à l'orthographe moderne, sans changer la ponctuation (qui, quoiqu'un peu datée, ne suscite pas de difficulté de lecture), la grammaire étant par ailleurs parfaitement conforme aux règles encore en usage. Il va de soi que tous les retours sont les bienvenus sur cette transcription, qui pourra faire l'objet de révisions futures en fonction de ceux-ci.
Published: 2023

5. Numerical analysis of an incompressible soft material poromechanics model using T-coercivity

Author: Barré, Mathieu, Grandmont, Céline, Moireau, Philippe, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), COmputational Mathematics for bio-MEDIcal Applications (COMMEDIA), Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Département de Mathématique [Bruxelles] (ULB), Faculté des Sciences [Bruxelles] (ULB), Université libre de Bruxelles (ULB)-Université libre de Bruxelles (ULB), and Sorbonne Université (SU)
Subjects: inf-sup stability, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], mixture theory, energy preserving scheme, total discretization, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], incompressible limit
Abstract: This article is devoted to the numerical analysis of the full discretization of a generalized poromechanical model resulting from the linearization of an initial model fitted to soft tissue perfusion. Our strategy here is based on the use of energy-based estimates and T-coercivity methods, so that the numerical analysis benefits from the essential tools used in the existence analysis of the continuous-time and continuous-space formulation. In particular, our T-coercivity strategy allows us to obtain the necessary inf-sup condition for the global system from the inf-sup condition restricted to a subsystem having the same structure as the Stokes problem. This allows us to prove that any finite element pair adapted to the Stokes problem is also suitable for this global poromechanical model regardless of porosity and permeability, generalizing previous results from the literature studying this model.
Published: 2023

6. Mortensen Observer for a class of variational inequalities - Lost equivalence with stochastic filtering approaches

Author: Chaintron, Louis-Pierre, Mateos González, Álvaro, Mertz, Laurent, Moireau, Philippe, Département de Mathématiques et Applications - ENS Paris (DMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), New York University [Shanghai], NYU System (NYU), and City University of Hong Kong [Hong Kong] (CUHK)
Subjects: [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation
Abstract: We address the problem of deterministic sequential estimation for a nonsmooth dynamics governed by a variational inequality. An example of such dynamics is the Skorokhod problem with a reflective boundary condition. For smooth dynamics, Mortensen introduced in 1968 a nonlinear estimator based on likelihood maximisation. Then, starting with Hijab in 1980, several authors established a connection between Mortensen's approach and the vanishing noise limit of the robust form of the so-called Zakai equation. In this paper, we investigate to what extent these methods can be developed for dynamics governed by a variational inequality.On the one hand, we address this problem by relaxing the inequality constraint by penalization: this yields an approximate Mortensen estimator relying on an approximating smooth dynamics. We verify that the equivalence between the deterministic and stochastic approaches holds through a vanishing noise limit.On the other hand, inspired by the smooth dynamics approach, we study the vanishing viscosity limit of the Hamilton-Jacobi equation satisfied by the Hopf-Cole transform of the solution of the robust Zakai equation. In contrast to the case of smooth dynamics, the zero-noise limit of the robust form of the Zakai equation cannot be understood in our case from the Bellman equation on the value function arising in Mortensen's procedure. This unveils a violation of equivalence for dynamics governed by a variational inequality between the Mortensen approach and the low noise stochastic approach for nonsmooth dynamics.
Published: 2023

7. Recommandations sur les « éditeurs de la zone grise »

Author: Blanqui, Frédéric, Canteaut, Anne, de Jong, Hidde, Imperiale, Sébastien, Mitton, Nathalie, Pallez, Guillaume, Pennec, Xavier, Rival, Xavier, Thirion, Bertrand, Deduction modulo, interopérabilité et démonstration automatique (DEDUCTEAM), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Méthodes Formelles (LMF), Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), Cryptologie symétrique, cryptologie fondée sur les codes et information quantique (COSMIQ), Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Analyse, ingénierie et contrôle des micro-organismes (MICROCOSME), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Grenoble Alpes (UGA), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Self-organizing Future Ubiquitous Network (FUN), Inria Lille - Nord Europe, Scalable Storage for Clouds and Beyond (KerData), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-SYSTÈMES LARGE ÉCHELLE (IRISA-D1), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), E-Patient : Images, données & mOdèles pour la médeciNe numériquE (EPIONE), Inria Sophia Antipolis - Méditerranée (CRISAM), Analyse Statique par Interprétation Abstraite (ANTIQUE), Département d'informatique - ENS Paris (DI-ENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria), Modèles et inférence pour les données de Neuroimagerie (MIND), IFR49 - Neurospin - CEA, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Inria Saclay - Ile de France, and Inria
Subjects: [INFO]Computer Science [cs], [MATH]Mathematics [math]
Abstract: Recommandations de la Commission d'Évaluation Inria, adoptées le 25 janvier 2023, sur certains éditeurs, notamment MDPI et Frontiers, qui prennent depuis quelques années une place significative dans les domaines de l'informatique et des mathématiques, disciplines où ils étaient absents par le passé.
Published: 2023

8. A biomechanics-based parametrized cardiac end-diastolic pressure–volume relationship for accurate patient-specific calibration and estimation

Author: Chapelle, Dominique, Le Gall, Arthur, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Service d'ophthalmologie [CHU Lariboisière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Lariboisière-Fernand-Widal [APHP], and Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Université Paris Cité (UPCité)
Subjects: cardiac passive behavior, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, cardiac biomechanical model, patient-specific modeling, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], EDPVR
Abstract: International audience; A simple power law has been proposed in the pioneering work of Klotz et al. (Am J Physiol Heart Circ Physiol 291(1):H403–H412, 2006) to approximate the end-diastolic pressure–volume relationship of the left cardiac ventricle, with limited inter-individual variability provided the volume is adequately normalized. Nevertheless, we use here a biomechanical model to investigate the sources of the remaining data dispersion observed in the normalized space, and we show that variations of the parameters of the biomechanical model realistically account for a substantial part of this dispersion. We therefore propose an alternative law based on the biomechanical model that embeds some intrinsic physical parameters, which directly enables personalization capabilities, and paves the way for related estimation approaches.
Published: 2023
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9. Modeling acto-myosin interaction: beyond the Huxley–Hill framework

Author: Chaintron, Louis-Pierre, Caruel, Matthieu, Kimmig, François, Département de Mathématiques et Applications - ENS Paris (DMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], Muscle contraction, Thermodynamics, Jump-diffusion process, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Molecular motors, Poisson random measures, Applied mathematics, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Applied probability
Abstract: Contractile force in muscle tissue is produced by the interaction of myosin molecular motors that bind and pull on specific sites located on surrounding actin filaments. The classical framework set by the landmark works of A.F. Huxley and T.L. Hill to model this active system is build on the central assumption that thermal fluctuations of a given myosin motor are sufficiently small so that it cannot interact with more than one binding site at any time. In this paper we present the physiological and mathematical limitations of this approach to motivate a new formulation that circumvent them without resorting to the more complex multi-site model paradigm. The acto-myosin system is now described as a Markov process combining Langevin driftdiffusion and Poisson jumps dynamics. We show that the corresponding system of Stochastic Differential Equation is well-posed and derive its Partial Differential Equation analog in order to obtain the thermodynamic balance laws. We finally show that by applying standard elimination procedures, a modified version of the original Huxley-Hill framework can be obtained as a reduced version of our model. Theoretical results are supported by numerical simulations where the model outputs are compared to benchmark experimental data.
Published: 2023

10. Reduced left ventricular dynamics modeling based on a cylindrical assumption

Author: Martin Genet, Jérôme Diaz, Dominique Chapelle, Philippe Moireau, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: Computational Theory and Mathematics, Applied Mathematics, Modeling and Simulation, Computational mechanics, Continuum mechanics on manifold, Reduced-order modeling, Biomedical Engineering, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Cardiac modeling, Molecular Biology, Software
Abstract: Biomechanical modeling and simulation is expected to play a significant role in the development of the next generation tools in many fields of medicine. However, full-fledged finite element models of complex organs such as the heart can be computationally very expensive, thus limiting their practical usability. Therefore, reduced models are much valuable to be used, e.g., for pre-calibration of full-fledged models, fast predictions, real-time applications, etc.. In this work, focused on the left ventricle, we develop a reduced model by defining reduced geometry & kinematics while keeping general motion and behavior laws, allowing to derive a reduced model where all variables & parameters have a strong physical meaning. More specifically, we propose a reduced ventricular model based on cylindrical geometry & kinematics, which allows to describe the myofiber orientation through the ventricular wall and to represent contraction patterns such as ventricular twist, two important features of ventricular mechanics. Our model is based on the original cylindrical model of [Guccione, McCulloch, & Waldman 1991; Guccione, Waldman, & McCulloch 1993], albeit with multiple differences: we propose a fully dynamical formulation, integrated into an open-loop lumped circulation model, and based on a material behavior that incorporates a fine description of contraction mechanisms; moreover, the issue of the cylinder closure has been completely reformulated; our numerical approach is novel as well, with consistent spatial (finite element) and time discretizations. Finally, we analyse the sensitivity of the model response to various numerical and physical parameters, and study its physiological response.
Published: 2023
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11. De la décomposition de domaine à la réduction de modèle pour les grandes structures non linéaires

Author: Bertrand Leturcq, Patrick Le Tallec, Laboratoire de Mécanique Systèmes et Simulation (LM2S), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: [SPI]Engineering Sciences [physics], Réduction de modèle, Mechanics of Materials, Model reduction, Assemblage de combustible, fluage, General Materials Science, Domain decomposition, Décomposition de domaines, Nuclear fuel assemblies, creep, contact
Abstract: International audience; The numerical simulation of multiscale and multiphysics problems requires efficient tools for spatial localization and model reduction. A general strategy combining Domain Decomposition and Nonuniform Transformation Field Analysis (NTFA) is proposed herein for the simulation of nuclear fuel assembliesat the scale of a full nuclear reactor. The model at subdomain level solves the full elastic problem but witha reduced nonlinear loading, based on simplified boundary conditions, reduced creep flow rules, projected sign preserving contact conditions, and a NTFA like reduced friction law to get the evolution of each slipping mode. With this loading reduction, the local solution can be explicitly obtained from a small set of precomputed elementary elastic solutions. The numerical tests indicate that considerable cost reduction (a factor of 50 to 1000) can be achieved while preserving engineering accuracy; . La simulation numérique de problèmes multi-échelles et multi-physiques nécessite des outils performants de localisation spatiale et de réduction de modèle. Une stratégie générale combinant la décomposition de domaine et l’analyse de champ de transformation non uniforme (NTFA) est proposée ici pour la simulation d’assemblages de combustible nucléaire à l’échelle d’un réacteur nucléaire complet. Le modèle au niveau du sous-domaine résout le problème élastique complet mais avec un chargement non linéaire réduit, basé sur des conditions aux limites simplifiées, des règles d’écoulement de fluage réduites, des conditions de contact préservant le signe projeté et une loi de frottement réduit de type NTFA pour obtenir l’évolution de chaque mode de glissement. Avec cette réduction de chargement, la solution locale peut être obtenue explicitement à partir d’un petit ensemble de solutions élastiques élémentaires précalculées. Les tests numériques indiquent qu’une réduction considérable des coûts (un facteur de 50 à 1000) peut être obtenue tout en préservant la précision du calcul
Published: 2023
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12. Acoustic and gravity waves in the ocean: a new derivation of a linear model from the compressible Euler equation

Author: Dubois, Juliette, Imperiale, Sébastien, Mangeney, Anne, Bouchut, François, Sainte-Marie, Jacques, Dubois, Juliette, Numerical Analysis, Geophysics and Ecology (ANGE), Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Institut de Physique du Globe de Paris (IPG Paris), Laboratoire Analyse et Mathématiques Appliquées (LAMA), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel, and This work was supported by grants from Région Ile-de-France and the project ERC-CG-2013-PE10-617472 SLIDEQUAKES
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [MATH.MATH-AP] Mathematics [math]/Analysis of PDEs [math.AP]
Abstract: In this paper we construct an accurate linear model describing the propagation of both acoustic and gravity waves in water. This original model is obtainedby the linearization of the compressible Euler equations, written in Lagrangian coordinates. The system is studied in the isentropic case, with a free surface, an arbitrary bathymetry, and vertical variations of the background temperature and density. We show that our model is an extension of some models from the litterature to the case of a non-barotropic fluid with a variable sound speed.Other models from the literature are recovered from our model through two asymptotic analysis, one for the incompressible regime and one for the acoustic regime. We also propose a method to write the model in Eulerian coordinates. Our model includes many physical properties, such as the existence of internal gravity waves or the variation of the sound speed with depth.
Published: 2023

13. Microrheology and structural quantification of hypercoagulable clots

Author: Wolff-Trombini, L, Ceripa, A, Moreau, J, Galinat, H, James, C, Westbrook, N, Allain, J, Biologie des maladies cardiovasculaires = Biology of Cardiovascular Diseases, Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Laboratoire Charles Fabry (LCF), Institut d'Optique Graduate School (IOGS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Régional Universitaire de Brest (CHRU Brest), CHU Bordeaux [Bordeaux], and ANR-11-EQPX-0029,MORPHOSCOPE 2,Imagerie et reconstruction multiéchelles de la morphogenèse. (Plateforme d'innovation technologique et méthodologique pour l'imagerie in vivo et la reconstruction des dynamiques multiéchelles de la morphogenèse)(2011)
Subjects: Biological Physics (physics.bio-ph), [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], FOS: Physical sciences, Physics - Biological Physics
Abstract: International audience; We propose a combination of microrheological and structural characterizations of fibrin networks to study blood hypercoagulability. Fibrin is the central element of coagulation as its polymerization creates the network of fibers in which platelets and red blood cells are included. This is a controlled process via cascades between various coagulation factors. An alteration in the concentrations of coagulation factors and inhibitors will lead to hypocoagulation or hypercoagulation. These changes in the conditions of polymerization of fibrin lead to the formation of networks with different architectures and thus modify its mechanical behavior. We have performed microrheology by recording Brownian motion of microbeads caught in the network of clots. The structure was quantified under the same polymerization conditions with confocal microscopy images. We have tested our approach by adding fibrinogen to the plasma, which leads to a stiffer, denser network with shorter fibers. The addition of coagulation Factor VIII at 400% induces the same correlated trend between a denser network and a higher modulus. This comparative approach is promising for the study of other conditions altering clot formation and may lead to a new diagnosis approach for hypercoagulability.
Published: 2023
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14. Measure of the hygroscopic expansion of human dentin

Author: Gharbi, Hakim, Wenlong, Wang, Giraudet, Chloé, Allain, Jean-Marc, Vennat, Elsa, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique Paris-Saclay (LMPS), CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Unité de Recherche Biomatériaux Innovants et Interfaces (URB2i (URP_4462)), Université Paris Cité (UPCité)-Université Sorbonne Paris Nord, This work has benefited from the financial support of the LabeX LaSIPS (ANR-10-LABX-0040-LaSIPS) managed by the French National Research Agency under the 'Investissements d'avenir' program (n°ANR-11-IDEX-0003-02)., and ANR-11-IDEX-0003,IPS,Idex Paris-Saclay(2011)
Subjects: DIC, Dentin, humidity, microscopy, FOS: Physical sciences, Medical Physics (physics.med-ph), strain measurement, mechanical properties, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Physics - Medical Physics, compression
Abstract: Background: Direct dental restoration implies a drying of the dentin substrate. This drying may induce significant strain in the dentin, affecting the bonding efficiency of the restoration. Objective: We measure the dilatation of dentine under changes of relative humidity as well as the impact of humidity on dentin elastic properties. This investigates the role of relative humidity variation during dental surgery on restoration lifetime. Methods: We have coupled an environmental chamber to control both temperature and humidity on the sample, with an optical microscope to measure precisely the strain on the sample surface, after a quantification of the measurement noise. This set-up is used on carefully prepared samples placed on a compression device to measure the elastic parameters. Results: Dentin dilates when the relative humidity increases, with a coefficient of hygroscopic expansion of typically 6.10-3 %.(%RH)-1. This dilatation occurs in about ten minutes. Young modulus and Poisson's ratio are not modified by the variation of relative humidity. Conclusions: Hygroscopic expansion is an order of magnitude larger than thermal expansion during dental surgery: around 0.3% with respect to 0.03%. These levels are low with respect to dental rupture, but may induce a significant decrease of the life-expectancy of a restoration.
Published: 2022

15. Right-left ventricular shape variations in tetralogy of Fallot: associations with pulmonary regurgitation

Author: Andrew D. McCulloch, Sachin Govil, Tarique Hussain, J. Omens, Radomir Chabiniok, Kuberan Pushparajah, James C. Perry, Alistair A. Young, Sanjeet Hegde, Charlene Mauger, Christopher J. Occleshaw, Liang Zhong, Kathleen Gilbert, Avan Suinesiaputra, University of Auckland [Auckland], Auckland Bioengineering Institute, University of California [San Diego] (UC San Diego), University of California (UC), King‘s College London, Czech Technical University in Prague (CTU), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), University of Texas Southwestern Medical Center [Dallas], Guy's and St Thomas' Hospital [London], Rady Children's Hospital San Diego, Department of Cardiology, Auckland District Health Board, Auckland, King's College London School of Medicine at Guy's, King's College and St Thomas' Hospitals, University of Leeds, Duke-NUS Medical School [Singapore], National Heart Centre Singapore (NHCS), University of California San Diego, La Jolla, CA, École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, and University of California San Diego, La Jolla
Subjects: Adult, Multivariate statistics, medicine.medical_specialty, Adolescent, 030204 cardiovascular system & hematology, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, Young Adult, 0302 clinical medicine, Predictive Value of Tests, Bayesian multivariate linear regression, Internal medicine, Pulmonary Valve Replacement, Pulmonary regurgitation, Medicine, Humans, Diseases of the circulatory (Cardiovascular) system, Radiology, Nuclear Medicine and imaging, Wall motion, cardiovascular diseases, Child, Ventricular function, Tetralogy of Fallot, Angiology, Retrospective Studies, Radiological and Ultrasound Technology, medicine.diagnostic_test, business.industry, Myocardial deformation, Research, Magnetic resonance imaging, Atlases, medicine.disease, Pulmonary Valve Insufficiency, Cross-Sectional Studies, RC666-701, Cardiology, Ventricular Function, Right, [SDV.IB]Life Sciences [q-bio]/Bioengineering, Cardiovascular magnetic resonance, Cardiology and Cardiovascular Medicine, business
Abstract: Background Relationships between right ventricular (RV) and left ventricular (LV) shape and function may be useful in determining optimal timing for pulmonary valve replacement in patients with repaired tetralogy of Fallot (rTOF). However, these are multivariate and difficult to quantify. We aimed to quantify variations in biventricular shape associated with pulmonary regurgitant volume (PRV) in rTOF using a biventricular atlas. Methods In this cross-sectional retrospective study, a biventricular shape model was customized to cardiovascular magnetic resonance (CMR) images from 88 rTOF patients (median age 16, inter-quartile range 11.8–24.3 years). Morphometric scores quantifying biventricular shape at end-diastole and end-systole were computed using principal component analysis. Multivariate linear regression was used to quantify biventricular shape associations with PRV, corrected for age, sex, height, and weight. Regional associations were confirmed by univariate correlations with distances and angles computed from the models, as well as global systolic strains computed from changes in arc length from end-diastole to end-systole. Results PRV was significantly associated with 5 biventricular morphometric scores, independent of covariates, and accounted for 12.3% of total shape variation (p Conclusion A biventricular atlas of rTOF patients quantified multivariate relationships between left–right ventricular morphometry and wall motion with pulmonary regurgitation. Regional RV dilation, LV reduction, LV septal-lateral flattening and increased RV strain were all associated with increased pulmonary regurgitant volume. Morphometric scores provide simple metrics linking mechanisms for structural and functional alteration with important clinical indices.
Published: 2021
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16. T-coercivité et problèmes mixtes

Author: Barré, Mathieu, Ciarlet, Patrick, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Propagation des Ondes : Étude Mathématique et Simulation (POEMS), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Unité de Mathématiques Appliquées (UMA), and École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract: Classically, the well-posedness of variational formulations of mixed linear problems is achieved through the inf-sup condition. In this note, we propose an alternative framework to study such problems by using the T-coercivity approach. This is a constructive approach that leads to the design of suitable approximations in a simple way. In general, the derivation of the uniform discrete inf-sup condition for the approximate problems stems straightforwardly from the study of the original problem. To support our view, we solve a series of classical mixed problems with the T-coercivity approach. Among others, the celebrated Fortin Lemma appears naturally in the numerical analysis of the approximate problems.; Classiquement, le caractère bien posé des formulations variationnelles de problèmes linéaires mixtes est obtenu à l'aide de la condition inf-sup. Dans cette note, nous proposons un cadre alternatif pour étudier de tels problèmes en utilisant la notion de T-coercivité. Il s'agit d'une approche constructive qui permet en outre de concevoir simplement des approximations numériques adaptées car la dérivation de la condition inf-sup discrète uniforme découle en général directement de l'étude du problème continu. Pour appuyer notre propos, nous résolvons une série de problèmes mixtes classiques grâce à la notion de Tcoercivité. Entre autres, le lemme de Fortin apparaît naturellement dans l'analyse numérique des problèmes discrets.
Published: 2022

17. Varying thin filament activation in the framework of the Huxley'57 model

Author: François Kimmig, Matthieu Caruel, Dominique Chapelle, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Laboratoire Modélisation et Simulation Multi-Echelle (MSME), and Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel
Subjects: Sarcomeres, Applied Mathematics, Biomedical Engineering, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Cardiac modeling, Actins, Actin Cytoskeleton, Computational Theory and Mathematics, Thick and thin filament activation, Modeling and Simulation, Huxley'57 model, Calcium, Mathematical modeling, Molecular Biology, Software, Muscle Contraction
Abstract: International audience; Muscle contraction is triggered by the activation of the actin sites of the thin filament by calcium ions. It results that the thin filament activation level varies over time. Moreover, this activation process is also used as a regulation mechanism of the developed force. Our objective is to build a model of varying actin site activation level within the classical Huxley'57 two-state framework. This new model is obtained as an enhancement of a previously proposed formulation of the varying thick filament activation within the same framework [1]. We assume that the state of an actin site depends on whether it is activated and whether it forms a cross-bridge with the associated myosin head, which results in four possible states. The transitions between the actin site states are controlled by the global actin sites activation level and the dynamics of these transitions is coupled with the attachment-detachment process. A preliminary calibration of the model with experimental twitch contraction data obtained at varying sarcomere lengths is performed.
Published: 2022
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18. Brain fragility among middle-aged and elderly patients from electroencephalogram during induction of anaesthesia

Author: Cyril Touchard, Jerome Cartailler, Fabrice Vallée, Claire Paquet, Etienne Gayat, Pierre Parutto, Groupe Hospitalier Saint Louis - Lariboisière - Fernand Widal [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Université de Paris (UP), UK Dementia Research Institute (UK DRI), University College of London [London] (UCL), Marqueurs cardiovasculaires en situation de stress (MASCOT (UMR_S_942 / U942)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Groupe Hospitalier Saint Louis - Lariboisière - Fernand Widal [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Université Sorbonne Paris Nord, Centre de Neurologie Cognitive [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Université Paris Diderot - Paris 7 (UPD7)-Hôpitaux Universitaires Saint-Louis, Lariboisière, Fernand-Widal, Optimisation thérapeutique en Neuropsychopharmacologie (OPTeN (UMR_S_1144 / U1144)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Paris (UP), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Université Paris Cité (UPCité), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Université Sorbonne Paris Nord, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPCité), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Zunara, Fatima
Subjects: 2019-20 coronavirus outbreak, [SDV.MHEP] Life Sciences [q-bio]/Human health and pathology, Coronavirus disease 2019 (COVID-19), business.industry, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Brain, Electroencephalography, Middle Aged, 03 medical and health sciences, 0302 clinical medicine, Anesthesiology and Pain Medicine, Fragility, Anesthesiology, 030202 anesthesiology, Anesthesia, Humans, Medicine, business, Short scientific reports and Correspondence, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, 030217 neurology & neurosurgery, Aged
Abstract: International audience; Cognitive decline (CD) is a common condition amongst elderly, affecting memory, language or thinking. Patients experiencing CD have a higher incidence rate of post-operative neurocognitive disorders 1. Moreover, for a fraction of these patients
Published: 2021
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19. HARP-I: A Harmonic Phase Interpolation Method for the Estimation of Motion From Tagged MR Images

Author: Hui Wang, Sergio Uribe, Michael D. Taylor, Hernán Mella, Joaquín Mura, Jaroslav Tintera, Julio Sotelo, Radomir Chabiniok, Pontificia Universidad Católica de Chile (UC), Universidade Federal de Santa Maria (UFSM), Cincinnati Children's Hospital Medical Center, Department of Mathematics [Prague] (FNSPE), Czech Technical University in Prague (CTU), School of Biomedical Engineering & Imaging Sciences [London], Guy's and St Thomas' Hospital [London]-King‘s College London, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), University of Texas Southwestern Medical Center [Dallas], Institute for Clinical and Experimental Medicine (IKEM), Valparaiso University, Universidade Federal de Santa Maria = Federal University of Santa Maria [Santa Maria, RS, Brazil] (UFSM), King‘s College London-Guy's and St Thomas' Hospital [London], École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Similarity (geometry), [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Phase (waves), Harmonic (mathematics), 030204 cardiovascular system & hematology, 030218 nuclear medicine & medical imaging, Harmonic analysis, Motion, 03 medical and health sciences, 0302 clinical medicine, Motion estimation, Image Processing, Computer-Assisted, Cardiac Strain, Electrical and Electronic Engineering, Cardiac MRI, Tagged MRI, SPAMM, HARP, Physics, Radiological and Ultrasound Technology, Sine-wave Modeling, CSPAMM, Harmonic Phase Analysis, Magnetic Resonance Imaging, Computer Science Applications, Noise, Cytokines, Astrophysics::Earth and Planetary Astrophysics, Carrier Proteins, Algorithm, Motion Estimation, Algorithms, Software, Interpolation
Abstract: International audience; We proposed a novel method called HARP-I, which enhances the estimation of motion from tagged Magnetic Resonance Imaging (MRI). The harmonic phase of the images is unwrapped and treated as noisy measurements of reference coordinates on a deformed domain, obtaining motion with high accuracy using Radial Basis Functions interpolations. Results were compared against Shortest Path HARP Refinement (SP-HR) and Sine-wave Modeling (SinMod), two harmonic image-based techniques for motion estimation from tagged images. HARP-I showed a favorable similarity with both methods under noise-free conditions, whereas a more robust performance was found in the presence of noise. Cardiac strain was better estimated using HARP-I at almost any motion level, giving strain maps with less artifacts. Additionally, HARP-I showed better temporal consistency as a new method was developed to fix phase jumps between frames. In conclusion, HARP-I showed to be a robust method for the estimation of motion and strain under ideal and non-ideal conditions.
Published: 2021
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20. A generic numerical solver for modeling the influence of stress conditions on guided wave propagation for SHM applications

Author: Dalmora, Andre, Imperiale, Alexandre, Imperiale, Sébastien, Moireau, Philippe, Département Imagerie et Simulation pour le Contrôle (DISC), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), European Project: 860104,H2020-MSCA-ITN-2019,GW4SHM, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: EOCs, 3D Shell Elements, Spectral Finite Elements, Prestresses, [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], Wave Propagation, Guided Waves, Numerical Simulation, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Struc- tural Health Monitoring
Abstract: In leading-edge industrial applications, assessing structure integrity is an important aspect of safety requirements. Structural Health Monitoring (SHM) proposes to use sensors and signal processing units in situ. One of the most attractive SHM techniques relies on ultrasonic guided waves. Modeling and simulation can be helpful tools for the design or the reliability assessment of SHM solutions. Currently available models developed for that purpose do not take into account effects of operational conditions such as internal stresses. These conditions can change wave propagation and therefore affect the interpretation of recorded signals. The objective of this work is to propose a model that fills this gap, and to derive corresponding numerical methods for elastic wave propagation in an arbitrarily deformed medium. Any hyperelastic constitutive law can be considered. As the structures considered are usually thin, we avoid shear-locking by using a shell formulation to solve the quasi-static problem representing the effects of structure loading. The computed displacement is then fed into a spectral elements method (SFEM) kernel to solve the time-domain linearized 3D elastodynamics problem representing the wave propagation. We validate our model against experimental data in the literature for an isotropic aluminium plate under tensile forces. Additionally, we apply these numerical procedures to a realistic bending experiment of a steel pipe. These validations steps show that our generic approach is able to capture the effects of stresses on ultrasonic guided wave propagation such as changes in wave velocity and induced anisotropy.
Published: 2022
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21. Some contributions to cardiac and pulmonary biomechanical modeling, simulation & estimation

Author: Genet, Martin, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Institut Polytechnique de Paris, and Patrick Le Tallec
Subjects: Growth & remodeling, Cœur, Modeling & Simulation, Biomécanique, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Heart, Motion tracking, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Poumon, Suivi de mouvement, Biomechanics, Modélisation & Simulation, Lung, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Croissance & remodelage
Published: 2022

22. A new reduced order model to represent the creep induced fuel assembly bow in PWR cores

Author: Leturcq, Bertrand, Le Tallec, Patrick, Pascal, Serge, Fandeur, Olivier, Lamorte, Nicolas, Laboratoire de Mécanique Systèmes et Simulation (LM2S), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Technologie d'Assemblage (LTA), FRAMATOME, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: Nuclear and High Energy Physics, Mechanical Engineering, [SPI.MECA.MSMECA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Materials and structures in mechanics [physics.class-ph], [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], creep, [SPI]Engineering Sciences [physics], [PHYS.MECA.STRU]Physics [physics]/Mechanics [physics]/Structural mechanics [physics.class-ph], Nuclear Energy and Engineering, PWR assembly bow, model reduction, General Materials Science, PWR assembly bow model reduction NTFA creep, Safety, Risk, Reliability and Quality, NTFA, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; Progressive deformation of nuclear fuel assemblies that occurs during a succession of irradiation cycles within PWR is at the core of numerous interactions. Progresses in the study of this phenomenon resulted from more and more complex models. To date, in the more advanced models, a mechanical model is combined to a hydraulic model of the core to address the fluid-structure interaction. A complete mechanical model of the core is generally built with a simplified finite element representation of each assembly using beam or simpler elements. The simplifying approach is required due to the high complexity of the multi-body multi-physics calculations. In order to improve the representativeness of the core model without penalizing the computational cost of the coupled simulations, a new method of model order reduction is proposed. It is specially adapted to this context and borrows the concepts of NTFA non-linear homogenization. The theoretical foundations and the application to a slender structure are presented. First, the method is validated on a simple case with spatially homogeneous characteristics. Finally, the case of the creep response of a fuel assembly under realistic heterogeneous loads is demonstrated.
Published: 2022
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23. Repurposing EEG monitoring of general anaesthesia for building biomarkers of brain ageing: An exploratory study

Author: David Sabbagh, Jérôme Cartailler, Cyril Touchard, Jona Joachim, Alexandre Mebazaa, Fabrice Vallée, Étienne Gayat, Alexandre Gramfort, Denis A. Engemann, Marqueurs cardiovasculaires en situation de stress (MASCOT (UMR_S_942 / U942)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Groupe Hospitalier Saint Louis - Lariboisière - Fernand Widal [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Université Sorbonne Paris Nord, Modelling brain structure, function and variability based on high-field MRI data (PARIETAL), Service NEUROSPIN (NEUROSPIN), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Département d’Anesthésie-Réanimation-SMUR [Hôpital Lariboisière], Hôpitaux Universitaire Saint-Louis, Lariboisière, Fernand-Widal, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Max Planck Institute for Human Cognitive and Brain Sciences [Leipzig] (IMPNSC), Max-Planck-Gesellschaft, Roche Pharma Research and Early Development [Basel] (pRED), F. Hoffmann-La Roche [Basel], PERI OP_BERNOULLI, PROMICE_BERNOULLI, ANR-20-CHIA-0016,BrAIN,Intelligence Artificielle et Neurosciences(2020), Zunara, Fatima, and Intelligence Artificielle et Neurosciences - - BrAIN2020 - ANR-20-CHIA-0016 - PNIA - VALID
Subjects: [SDV.MHEP] Life Sciences [q-bio]/Human health and pathology, machine learning, propofol, electroencephalogram (EEG), sevoflurane, general anaesthesia, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], brain ageing, burst suppression, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
Abstract: BackgroundEEG is a common tool for monitoring anaesthetic depth but is rarely reused at large for biomedical research. This study sets out to explore repurposing of EEG during anaesthesia to learn biomarkers of brain ageing in the absence of consciousness.MethodsWe focused on brain age estimation as an example. Using machine learning, we reanalysed 4-electrodes EEG of 323 patients under propofol and sevoflurane. We included spatio-spectral features from stable anaesthesia for EEG-based age prediction applying recently published reference methods. Anaesthesia was considered stable when 95% of the total power was below a frequency between 8Hz and 13Hz.ResultsWe considered moderate-risk patients (ASA ConclusionsEEG from general anaesthesia may enable state-of-the-art brain age prediction. Yet, differences between anaesthetic drugs can impact the effectiveness of repurposing EEG from anaesthesia. To unleash the dormant potential of repurposing EEG-monitoring for clinical and health research, in the absence of consciousness, collecting larger datasets with precisely documented drug dosage will be key enabling factors.
Published: 2022
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24. Combinaison d'éléments de coque et d'éléments finis spectraux transitoires pour les problèmes de propagation d'ondes guidées dans des structures déformées

Author: Dalmora, Andre Luiz, Imperiale, Alexandre, Imperiale, Sébastien, Moireau, Philippe, Département Imagerie et Simulation pour le Contrôle (DISC), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Société Française d'Acoustique, and Laboratoire de Mécanique et d'Acoustique
Subjects: [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract: International audience; Dans les applications industrielles de pointe, l'évaluation de l'intégrité des structures est un aspect important des exigences de sécurité. Cependant, l'application des méthodes classiques d'évaluation non destructive peut être coûteuse et entraîne généralement des interruptions d'activité. Pour surmonter ces difficultés, le Structural Health Monitoring(SHM) propose d'utiliser des capteurs et des unités de traitement du signal in situ. Les ondes ultrasonores guidées constituent l'un des moyens de mettre en œuvre les systèmes SHM. Elles peuvent être utilisées pour évaluer les caractéristiques internes du matériau, telles que ses propriétés/défauts. Ces systèmes SHM sont déjà mis en œuvre dans des applications industrielles, mais leur utilisation est limitée en raison des conditions environnementales et opérationnelles. Un exemple typique est celui des charges opérationnelles induisant de grandes déformations et par conséquent des contraintes internes qui entraînent des changements dans la propagation des ondes[1]. Pour interpréter les signaux mesurés dans ce contexte, il est important que les efforts de modélisation de la propagation des ondes prennent en compte ce phénomène. L'objectif de notre travail est de présenter un modèle, et les méthodes numériques correspondantes, pour la propagation élastique des ondes dans un milieu précontraint. Comme les structures considérées sont généralement minces, nous utilisons une formulation de coque[2] pour la mécanique nonlinéaire pour résoudre le problème statique, représentant les effets du chargement de la structure. Le déplacement calculé est ensuite introduit dans un noyau de la méthode des éléments spectraux(SFEM)[3] pour résoudre le problème élastodynamique linéarisé dans le domaine temporel, représentant la propagation des ondes
Published: 2022

25. Estimation of Regional Pulmonary Compliance in Idiopathic Pulmonary Fibrosis Based on Personalized Lung Poromechanical Modeling

Author: Cécile Patte, Pierre-Yves Brillet, Catalin Fetita, Jean-François Bernaudin, Thomas Gille, Hilario Nunes, Dominique Chapelle, Martin Genet, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Hypoxie et Poumon : pneumopathologies fibrosantes, modulations ventilatoires et circulatoires (H&P), UFR SMBH-Université Sorbonne Paris Nord, Hôpital Avicenne [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Institut Polytechnique de Paris (IP Paris), Département Advanced Research And Techniques For Multidimensional Imaging Systems (TSP - ARTEMIS), Institut Mines-Télécom [Paris] (IMT)-Télécom SudParis (TSP), ARMEDIA (ARMEDIA-SAMOVAR), Services répartis, Architectures, MOdélisation, Validation, Administration des Réseaux (SAMOVAR), Institut Mines-Télécom [Paris] (IMT)-Télécom SudParis (TSP)-Institut Mines-Télécom [Paris] (IMT)-Télécom SudParis (TSP), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), and ANR-19-CE45-0007,LungManyScale,Biomécanique Computationnelle Pulmonaire: Modélisation Multi-échelle et Estimation(2019)
Subjects: Physiology (medical), Biomedical Engineering, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Humans, respiratory system, Tomography, X-Ray Computed, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Lung, Idiopathic Pulmonary Fibrosis, respiratory tract diseases
Abstract: Pulmonary function is tightly linked to the lung mechanical behavior, especially large deformation during breathing. Interstitial lung diseases, such as idiopathic pulmonary fibrosis (IPF), have an impact on the pulmonary mechanics and consequently alter lung function. However, IPF remains poorly understood, poorly diagnosed, and poorly treated. Currently, the mechanical impact of such diseases is assessed by pressure–volume curves, giving only global information. We developed a poromechanical model of the lung that can be personalized to a patient based on routine clinical data. The personalization pipeline uses clinical data, mainly computed tomography (CT) images at two time steps and involves the formulation of an inverse problem to estimate regional compliances. The estimation problem can be formulated both in terms of “effective”, i.e., without considering the mixture porosity, or “rescaled,” i.e., where the first-order effect of the porosity has been taken into account, compliances. Regional compliances are estimated for one control subject and three IPF patients, allowing to quantify the IPF-induced tissue stiffening. This personalized model could be used in the clinic as an objective and quantitative tool for IPF diagnosis.
Published: 2022
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26. Modélisation biomécanique cardiovasculaire personnalisée pour améliorer l'interprétation des données cliniques et aider à planifier les interventions chez les patients atteints de cardiopathie congénitale

Author: Gusseva, Maria, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Institut Polytechnique de Paris, Dominique Chapelle, and Radomir Chabiniok
Subjects: Ventricular overload, Time-Synchronization of clinical data, [SPI.OTHER]Engineering Sciences [physics]/Other, [SDV.OT]Life Sciences [q-bio]/Other [q-bio.OT], [PHYS.PHYS]Physics [physics]/Physics [physics], Contractilité du myocarde, Médecine personnalisée, Valvular heart disease, Personalized medicine, Surcharge ventriculaire, Cardiopathie valvulaire, Synchronisation temporelle des données cliniques, Modélisation biomécanique, Biomechanical modeling, Myocardial contractility, Cardiopathie congénitale, Congenital heart disease
Abstract: This PhD thesis is an interdisciplinary research that deals with applied biomechanical modeling of the cardiovascular system in patients with congenital heart diseases . The aim is to explore the potential of biomechanical modeling to assist in clinical decision-making.First, we explored the ability of a previously developed biomechanical model to augment the interpretation of clinical data for patients with tetralogy of Fallot after repair (rTOF) prior to and after pulmonary valve replacement (PVR). Patient-specific models of the right ventricle (RV) and pulmonary circulation were built for 20 subjects pre- and post-PVR using cardiovascular magnetic resonance (CMR) and pressure catheter data. These models were subjected to the effects of pulmonary valve (PV) regurgitation and/or RV outflow tract (RVOT) obstruction. The models provided patient-specific indices of myocardial contractility pre- and post-PVR. The results showed a decrease of contractility in all patients post-PVR. Patients with predominantly RVOT obstruction experienced a higher level of contractility decrease whereas ceasing the regurgitation itself did not lead to a significant reduction in contractility. After this detailed study of pathophysiology of the overloaded RVs pre- and post-PVR, we explored the ability of the model to predict the response of ventricular mechanics when progressively decreasing the afterload of the RVs in patients with rTOF. Pre-PVR patient-specific models were used and cessation of PV regurgitation and progressive decrease of RVOT resistance were assumed. The resulting in silico relationships between the contractility and RVOT resistance post-PVR appeared to be linear, and consistent with that given by the patient-specific post-PVR models.For patients with single-ventricle hearts undergoing CMR combined with a pressure catheter (as part of planning for complex surgery), the model was used to synchronize in time the catheter-pressure data and the ventricular volumes obtained by CMR. This model-assisted time-synchronization produces high quality P-V loops that yield more accurate indices of myocardial energetics (maximum value of time-varying elastance (E_max) and stroke work) and hence could be used to ameliorate the clinical interpretation.Finally, we compared the indices of E_max and maximum time derivative of ventricular pressure, max(dP/dt), when obtained directly from the clinical measurements vs. model-derived contractility and max(dP/dt). All data- and model-derived indices showed a good agreement. In addition, a potential application of model-derived max⁡(dP/dt) as a model-based data filter was emphasized.Overall, this thesis demonstrated (1) an ability of biomechanical modeling to provide additional mechanical indices of ventricular function and their evolution under different loading conditions, which has the potential to contribute into the planning of optimal therapy; (2) an application of the model to provide robust clinical data processing of a variety of data acquisition protocols; and (3) a correspondence of model-derived indices with clinically accepted surrogate measures of contractility. In conclusion, this thesis showed that biomechanical modeling could be deployed in a clinical environment to address various types of problems towards the delivery of personalized healthcare solutions.; Cette thèse de doctorat est une recherche interdisciplinaire qui porte sur la modélisation biomécanique appliquée du système cardiovasculaire chez les patients atteints de cardiopathies congénitales. L'objectif est d'explorer le potentiel de la modélisation biomécanique pour aider à la prise de décision clinique.Tout d'abord, nous avons exploré la capacité d'un modèle biomécanique précédemment développé à améliorer l'interprétation des données cliniques pour les patients atteints de tétralogie de Fallot après réparation (TOFr) avant et après le remplacement de la valve pulmonaire (RVP). Des modèles personnalisés du ventricule droit (VD) et de la circulation pulmonaire ont été construits pour 20 sujets avant et après le RVP à l'aide de données obtenues par résonance magnétique cardiovasculaire (RMC) et par cathéter de pression. Ces modèles ont été soumis aux effets de la régurgitation de la valve pulmonaire (VP) et/ou de l'obstruction du canal de sortie du VD (RVOT). Les modèles ont fourni des indices de contractilité myocardique personnalisés avant et après la RPV. Les résultats ont montré une diminution de la contractilité chez tous les patients après la RVP. Les patients présentant une obstruction prédominante de l'RVOT ont connu une diminution plus importante de la contractilité, alors que l'arrêt de la régurgitation elle-même n'a pas entraîné de réduction significative de la contractilité. Après cette étude détaillée de la pathophysiologie des VD surchargés avant et après la RVP, nous avons exploré la capacité du modèle à prédire la réponse de la mécanique ventriculaire lors de la diminution progressive de la post-charge des VD chez les patients atteints de TOFr. Des modèles pré-PVR personnalisés ont été utilisés et l'arrêt de la régurgitation PV et la diminution progressive de la résistance RVOT ont été supposés. Les relations in silico résultantes entre la contractilité et la résistance de l'RVOT après la RVP sont apparues linéaires et cohérentes avec celles données par les modèles post-RVP spécifiques aux patients.Pour les patients dont le cœur est constitué d'un seul ventricule et qui subissent une RMC combinée à un cathéter de pression (dans le cadre de la planification d'une chirurgie complexe), le modèle a été utilisé pour synchroniser dans le temps les données de pression du cathéter et les volumes ventriculaires obtenus par RMC. Cette synchronisation temporelle assistée par le modèle produit des boucles P-V de haute qualité qui donnent des indices plus précis de l'énergétique cardiaque (valeur maximale de l'élastance variable dans le temps (E_max) et du travail systémique) et qui pourraient donc être utilisés pour améliorer l'interprétation clinique.Enfin, nous avons comparé les indices de E_max et de la dérivée temporelle maximale de la pression ventriculaire, max(dP/dt), obtenus directement à partir des mesures cliniques, avec la contractilité et le max(dP/dt) dérivés du modèle. Tous les indices dérivés des données et du modèle ont montré une bonne concordance. De plus, une application potentielle du max(dP/dt) dérivé du modèle comme filtre de données basé sur le modèle a été soulignée.Dans l'ensemble, cette thèse a démontré (1) la capacité de la modélisation biomécanique à fournir des indices mécaniques supplémentaires de la fonction ventriculaire et leur évolution dans différentes conditions de charge, ce qui pourrait contribuer à la planification d'une thérapie optimale ; (2) une application du modèle pour fournir un traitement robuste des données cliniques d'une variété de protocoles d'acquisition de données ; et (3) une correspondance des indices dérivés du modèle avec des mesures de substitution de la contractilité acceptées cliniquement. En conclusion, cette thèse a montré que la modélisation biomécanique pouvait être déployée dans un environnement clinique pour résoudre divers types de problèmes en médecine personnalisée.
Published: 2022

27. Special Issue of the VPH2020 Conference: 'Virtual Physiological Human: When Models, Methods and Experiments Meet the Clinic'

Author: Irene E. Vignon-Clementel, Dominique Chapelle, Abdul I. Barakat, Aline Bel-Brunon, Philippe Moireau, Eric Vibert, SImulations en Médecine, BIOtechnologie et ToXicologie de systèmes multicellulaires (SIMBIOTX ), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Laboratoire d'hydrodynamique (LadHyX), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut Polytechnique de Paris (IP Paris), Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Physiopathologie et traitement des maladies du foie, Hôpital Paul Brousse-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay, and Lamcos - gestionnaires Hal, Lamcos - gestionnaires Hal
Subjects: [SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], Biomedical Engineering, [INFO]Computer Science [cs], [INFO] Computer Science [cs], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; No abstract available
Published: 2022
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28. Time-Synchronization of Interventional Cardiovascular Magnetic Resonance Data Using a Biomechanical Model for Pressure-Volume Loop Analysis

Author: Maria Gusseva, Daniel A. Castellanos, Joshua S. Greer, Mohamed Abdelghafar Hussein, Keren Hasbani, Gerald Greil, Surendranath R. Veeram Reddy, Tarique Hussain, Dominique Chapelle, Radomír Chabiniok, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Boston Children's Hospital, Harvard Medical School [Boston] (HMS), University of Texas Southwestern Medical Center [Dallas], Kafrelsheikh University, and University of Texas at Austin [Austin]
Subjects: [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Radiology, Nuclear Medicine and imaging, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2022
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29. Discrete time formulations as time discretization strategies in data assimilation

Author: Philippe Moireau, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: Mortensen estimator, Least squares minimization, [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], Kalman filtering, Luenberger observer, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract: International audience; Data assimilation combines control theory and scientific computing to propose a set of methods for coupling dynamic models and data sequences for estimation and prediction in all engineering domains. Data assimilation naturally raises the question of how the developed control and optimization methods interact with the discretization of the underlying physical models, in particular their temporal discretization. We would like to present here some of the best known techniques developed for discrete-time models, which are essentially based on a mechanism involving model prediction on the one hand and data correction on the other. We show that they can be considered as specific discretizations of the data assimilation strategies proposed for continuous-time models in the sense of a discretization-and-then-control approach. This paradigm justifies the stability of these prediction-correction schemes, paving the way for convergence properties and justifying their popularity in practice.
Published: 2022
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30. An efficient numerical method for time domain electromagnetic wave propagation in co-axial cables

Author: Akram Beni-Hamad, Geoffrey Beck, Sébastien Imperiale, Patrick Joly, Beck, Geoffrey, Département de Mathématiques et Applications - ENS Paris (DMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Propagation des Ondes : Étude Mathématique et Simulation (POEMS), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Unité de Mathématiques Appliquées (UMA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: Computational Mathematics, Numerical Analysis, Edge elements, Hybrid numerical method, Applied Mathematics, Coaxial cables, Telegrapher's models, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Maxwell's equation, Numerical simulation, [MATH.MATH-AP] Mathematics [math]/Analysis of PDEs [math.AP], [MATH.MATH-NA] Mathematics [math]/Numerical Analysis [math.NA], [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract: In this work, we construct an efficient numerical method to solve 3D Maxwell’s equations in coaxial cables. Our strategy is based upon a hybrid explicit-implicit time discretization combined with edge elements on prisms and numerical quadrature. One of the objectives is to validate numerically generalized telegrapher’s models that are used to simplify the 3D Maxwell equations into a 1D problem. This is the object of the second part of the article.
Published: 2022
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31. Méthodes mathématiques et numériques pour des problèmes depropagation d’ondes double échelles

Author: Imperiale, Sébastien, Imperiale, Sébastien, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Institut polytechnique de Paris, and Bruno Desprès
Subjects: Equation d'onde, Discrétisation en temps, Asymptotic analysis, Time discretisation, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Wave equation, Analyse asymptotique, [MATH.MATH-AP] Mathematics [math]/Analysis of PDEs [math.AP]
Published: 2022

32. On the structural origin of the anisotropy in the myocardium: Multiscale modeling and analysis

Author: Nicole Tueni, Jean-Marc Allain, Martin Genet, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: Biomaterials, Mechanics of Materials, Biomedical Engineering, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph]
Abstract: International audience; Due to structural heterogeneities within the tissue, the myocardium displays an orthotropic material behavior. However, the link between the microstructure and the macroscopic mechanical properties is still not fully established. In particular, if it is admitted that the cardiomyocyte organization induces a transversely isotropic symmetry, the relative role in the observed orthotropic symmetry of cardiomyocyte orientation variation and perimysium collagen "sheetlet" structure, two mechanisms occurring at different scales, is still a matter of debate. In order to shed light on this question, we designed a multiscale model of the myocardium, bridging the cell, sheetlet and tissue scales. More precisely, we compared the macroscopic anisotropy obtained by homogenization of different mesostructures consisting in cardiomyocytes and extracellular collageneous layers, also taking into account the variation of cardiomyocyte and sheetlet orientations on the macroscale, to available experimental data. This study confirms the importance of sheetlets layers in assuring the tissue's anisotropic response, as cardiomyocytes-only mesostructures cannot reproduce the observed anisotropy. Moreover, our model shows the existence of a size effect in the myocardial tissue shear properties, which will require further experimental analysis.
Published: 2022
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33. Kernel representation of Kalman observer and associated H-matrix based discretization

Author: Matthieu Aussal, Philippe Moireau, Inversion of Differential Equations For Imaging and physiX (IDEFIX), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-École polytechnique (X)-EDF (EDF), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: Computational Mathematics, Riccati equation, Control and Optimization, Control and Systems Engineering, [MATH]Mathematics [math], Infinte dimensional systems, data assimilation
Abstract: In deterministic estimation, applying a Kalman filter to a dynamical model based on partial differential equations is theoretically seducing but solving the associated Riccati equation leads to a so-called curse of dimensionality for its numerical implementation. In this work, we propose to entirely revisit the theory of Kalman filters for parabolic problems where additional regularity results proves that the Riccati equation solution belongs to the class of Hilbert-Schmidt operators. The regularity of the associated kernel then allows to proceed to the numerical analysis of the Kalman full space-time discretization in adapted norms, hence justifying the implementation of the related Kalman filter numerical algorithm with H-matrices typically developed for integral equations discretization.
Published: 2022
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34. Analysis of a linearized poromechanics model for incompressible and nearly incompressible materials

Author: Barré, Mathieu, Grandmont, Céline, Moireau, Philippe, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), COmputational Mathematics for bio-MEDIcal Applications (COMMEDIA), Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Département de Mathématique [Bruxelles] (ULB), Faculté des Sciences [Bruxelles] (ULB), Université libre de Bruxelles (ULB)-Université libre de Bruxelles (ULB), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Sorbonne Université (SU), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Grandmont, Celine
Subjects: [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [MATH] Mathematics [math], [MATH.MATH-AP] Mathematics [math]/Analysis of PDEs [math.AP], [MATH]Mathematics [math]
Abstract: International audience; In this paper, we thoroughly analyze the linearized version of a poromechanics model developed to simulate biological tissues perfusion. This is a fully dynamical model in which the fluid and solid equations are strongly coupled through the interstitial pressure. As such, it generalizes Darcy, Brinkman and Biot equations of poroelasticity. The mathematical and numerical analysis of this model was first performed for a compressible porous material. Here, we focus on the nearly incompressible case with a semigroup approach that also enables to prove the existence of weak solutions. We show the existence and uniqueness of strong and weak solutions in the incompressible limit, for which a non-standard divergence constraint arises. Due to the special form of the coupling, the underlying problem is not coercive. Nevertheless, by using the notion of T-coercivity, we obtain stability estimates and well-posedness results. Our study also provides guidelines to propose a stable and robust approximation of the problem with mixed finite elements. In particular, we recover an inf-sup condition independent of the phase field. Finally, we investigate numerically the elliptic regularity of the associated steady-state problem and illustrate the sensitivity of the solution with respect to the different model parameters.
Published: 2021
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35. Using Population Based Kalman Estimator to Model COVID-19 Epidemic in France: Estimating the Effects of Non-Pharmaceutical Interventions on the Dynamics of Epidemic

Author: Collin, Annabelle, Hejblum, Boris P., Vignals, Carole, Lehot, Laurent, Thiébaut, Rodolphe, Moireau, Philippe, Prague, MéLanie, Institut de Mathématiques de Bordeaux (IMB), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS), Bordeaux population health (BPH), Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM), Statistics In System biology and Translational Medicine (SISTM), Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)- Bordeaux population health (BPH), Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM), Vaccine Research Institute (VRI), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), CHU de Bordeaux Pellegrin [Bordeaux], Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS), Modélisation Mathématique pour l'Oncologie (MONC), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Institut Bergonié [Bordeaux], UNICANCER-UNICANCER-Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, and Hejblum, Boris
Subjects: [SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases, [STAT.AP]Statistics [stat]/Applications [stat.AP], Epidemic modeling, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], Non-pharmaceutical interventions, COVID-19, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, Population estimation, COVID-19 Epidemic modeling Non-pharmaceutical interventions Kalman filters Population estimation, Kalman filters, [MATH.MATH-ST] Mathematics [math]/Statistics [math.ST]
Abstract: International audience; In response to the ongoing COVID-19 pandemic caused by SARS-CoV-2, governments are taking a wide range of non-pharmaceutical interventions (NPI). These measures include interventions as stringent as strict lockdown but also school closure, bar and restaurant closure, curfews and barrier gestures i.e . social distancing. Disentangling the effectiveness of each NPI is crucial to inform response to future outbreaks. To this end, we first develop a multi-level estimation of the French COVID-19 epidemic over a period of one year. We rely on a global extended Susceptible-Infectious-Recovered (SIR) mechanistic model of the infection including a dynamical (over time) transmission rate containing a Wiener process accounting for modeling error. Random effects are integrated following an innovative population approach based on a Kalman-type filter where the log-likelihood functional couples data across French regions. We then fit the estimated time-varying transmission rate using a regression model depending on NPI, while accounting for vaccination coverage, apparition of variants of concern (VoC) and seasonal weather conditions. We show that all NPI considered have an independent significant effect on the transmission rate. We additionally demonstrate a strong effect from weather conditions which decrease transmission during the summer period, and also estimate increased transmissibility of VoCs.
Published: 2021
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36. Prediction of Ventricular Mechanics After Pulmonary Valve Replacement in Tetralogy of Fallot by Biomechanical Modeling: A Step Towards Precision Healthcare

Author: Camille Hancock Friesen, Gerald F. Greil, Radomir Chabiniok, Maria Gusseva, Dominique Chapelle, Tarique Hussain, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), University of Texas Southwestern Medical Center [Dallas], University of Nebraska Medical Center, University of Nebraska System, Czech Technical University in Prague (CTU), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: medicine.medical_specialty, medicine.medical_treatment, 0206 medical engineering, Biomedical Engineering, 02 engineering and technology, 030204 cardiovascular system & hematology, Contractility, 03 medical and health sciences, 0302 clinical medicine, Afterload, Valve replacement, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, Internal medicine, Pulmonary Valve Replacement, Medicine, ComputingMilieux_MISCELLANEOUS, Ventricular mechanics, Tetralogy of Fallot, business.industry, valvular heart disease, medicine.disease, 020601 biomedical engineering, 3. Good health, medicine.anatomical_structure, Ventricle, Cardiology, [SDV.IB]Life Sciences [q-bio]/Bioengineering, business, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
Abstract: Clinical indicators of heart function are often limited in their ability to accurately evaluate the current mechanical state of the myocardium. Biomechanical modeling has been shown to be a promising tool in addition to clinical indicators. By providing a patient-specific measure of myocardial active stress (contractility), biomechanical modeling can enhance the precision of the description of patient’s pathophysiology at any given point in time. In this work we aim to explore the ability of biomechanical modeling to predict the response of ventricular mechanics to the progressively decreasing afterload in repaired tetralogy of Fallot (rTOF) patients undergoing pulmonary valve replacement (PVR) for significant residual right ventricular outflow tract obstruction (RVOTO). We used 19 patient-specific models of patients with rTOF prior to pulmonary valve replacement (PVR), denoted as PSMpre, and patient-specific models of the same patients created post-PVR (PSMpost)—both created in our previous published work. Using the PSMpre and assuming cessation of the pulmonary regurgitation and a progressive decrease of RVOT resistance, we built relationships between the contractility and RVOT resistance post-PVR. The predictive value of such in silico obtained relationships were tested against the PSMpost, i.e. the models created from the actual post-PVR datasets. Our results show a linear 1-dimensional relationship between the in silico predicted contractility post-PVR and the RVOT resistance. The predicted contractility was close to the contractility in the PSMpost model with a mean (± SD) difference of 6.5 (± 3.0)%. The relationships between the contractility predicted by in silico PVR vs. RVOT resistance have a potential to inform clinicians about hypothetical mechanical response of the ventricle based on the degree of pre-operative RVOTO.
Published: 2021
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37. Estimation for dynamical systems using a population-based Kalman filter – Applications in computational biology

Author: Collin, Annabelle, Prague, Mélanie, Moireau, Philippe, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Statistics In System biology and Translational Medicine (SISTM), Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)- Bordeaux population health (BPH), Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM), Modélisation Mathématique pour l'Oncologie (MONC), Institut de Mathématiques de Bordeaux (IMB), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Institut Bergonié [Bordeaux], UNICANCER-UNICANCER-Inria Bordeaux - Sud-Ouest, Institut Polytechnique de Bordeaux (Bordeaux INP), Centre National de la Recherche Scientifique (CNRS), Vaccine Research Institute (VRI), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Institut Bergonié [Bordeaux], Centre National de la Recherche Scientifique (CNRS)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Inria Saclay - Ile de France, and Collin, Annabelle
Subjects: Epidemiology, Kalman Filters, COVID-19, [MATH.MATH-OC] Mathematics [math]/Optimization and Control [math.OC], Mixed-effect estimation, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Non linear mixed-effect models, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], [SDV.SP.PHARMA] Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, population-based sequential estimation, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Pharmacokinetics, [INFO.INFO-MO] Computer Science [cs]/Modeling and Simulation, [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], [MATH.MATH-ST] Mathematics [math]/Statistics [math.ST], data assimilation
Abstract: International audience; Estimation of dynamical systems - in particular, identification of their parameters - is fundamental in computational biology, e.g., pharmacology, virology, or epidemiology, to reconcile model runs with available measurements. Unfortunately, the mean and variance priorities of the parameters must be chosen very appropriately to balance our distrust of the measurements when the data are sparse or corrupted by noise. Otherwise, the identification procedure fails. One option is to use repeated measurements collected in configurations with common priorities - for example, with multiple subjects in a clinical trial or clusters in an epidemiological investigation. This shared information is beneficial and is typically modeled in statistics using nonlinear mixed-effects models. In this paper, we present a data assimilation method that is compatible with such a mixed-effects strategy without being compromised by the potential curse of dimensionality. We define population-based estimators through maximum likelihood estimation. We then develop an equivalent robust sequential estimator for large populations based on filtering theory that sequentially integrates data. Finally, we limit the computational complexity by defining a reduced-order version of this population-based Kalman filter that clusters subpopulations with common observational backgrounds. The performance of the resulting algorithm is evaluated against classical pharmacokinetics benchmarks. Finally, the versatility of the proposed method is tested in an epidemiological study using real data on the hospitalisation of COVID-19 patients in the regions and departments of France.
Published: 2021
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38. Biomechanical Modeling to Inform Pulmonary Valve Replacement in Tetralogy of Fallot Patients after Complete Repair

Author: Gerald F. Greil, Radomir Chabiniok, Keren Hasbani, Dominique Chapelle, Camille L. Hancock Friesen, Maria Gusseva, Animesh Tandon, Cécile Patte, Philippe Moireau, Tarique Hussain, Martin Genet, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), University of Texas Southwestern Medical Center [Dallas], University of Texas at Austin [Austin], Czech Technical University in Prague (CTU), King‘s College London, Guy's and St Thomas' Hospital [London], École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris
Subjects: Adult, Male, Reoperation, medicine.medical_specialty, Percutaneous, Heart Ventricles, 0206 medical engineering, Magnetic Resonance Imaging, Cine, 02 engineering and technology, 030204 cardiovascular system & hematology, Models, Biological, Article, Contractility, 03 medical and health sciences, 0302 clinical medicine, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, Cardiovascular modeling, Pulmonary Valve Replacement, Internal medicine, medicine.artery, Humans, Medicine, Abnormalities, Multiple, Cardiac Surgical Procedures, Retrospective Studies, Tetralogy of Fallot, Heart Valve Prosthesis Implantation, Cardiovascular magnetic resonance imaging, Pulmonary Valve, medicine.diagnostic_test, business.industry, Hemodynamics, Magnetic resonance imaging, Retrospective cohort study, Translational research, medicine.disease, 020601 biomedical engineering, Personalized medicine, Pulmonary Valve Insufficiency, Pulmonary artery, Cardiology, Female, Biomechanical model, [SDV.IB]Life Sciences [q-bio]/Bioengineering, Myocardial contractility, Cardiology and Cardiovascular Medicine, business, Follow-Up Studies
Abstract: BACKGROUND: A biomechanical model of the heart can be used to incorporate multiple data sources (electrocardiography, imaging, invasive hemodynamics). The purpose of this study was to use this approach in a cohort of patients with tetralogy of Fallot after complete repair (rTOF) to assess comparative influences of residual right ventricular outflow tract obstruction (RVOTO) and pulmonary regurgitation on ventricular health. METHODS: Twenty patients with rTOF who underwent percutaneous pulmonary valve replacement (PVR) and cardiovascular magnetic resonance imaging were included in this retrospective study. RESULTS: RV contractility before PVR (mean 66 ± kPa, mean ± standard deviation) was increased in patients with rTOF compared with normal RV (38–48 kPa) (P < 0.05). The contractility decreased significantly in all patients after PVR (P < 0.05). Patients with predominantly RVOTO demonstrated greater reduction in contractility (median decrease 35%) after PVR than those with predominant pulmonary regurgitation (median decrease 11%). The model simulated post-PVR decreased EDV for the majority and suggested an increase of Q(eff)—both in line with published data. CONCLUSIONS: This study used a biomechanical model to synthesize multiple clinical inputs and give an insight into RV health. Individualized modeling allows us to predict the RV response to PVR. Initial data suggest that residual RVOTO imposes greater ventricular work than isolated pulmonary regurgitation. Biomechanical models specific to individual patient and physiology (before and after PVR) were created and used to estimate the RV myocardial contractility. The ability of models to capture post-PVR changes of right ventricular (RV) end-diastolic volume (EDV) and effective flow in the pulmonary artery (Qeff) was also compared with expected values.
Published: 2021
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39. Dimensional reduction of a poromechanical cardiac model for myocardial perfusion studies

Author: Radomír Chabiniok, Bruno Burtschell, Dominique Chapelle, Philippe Moireau, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), and University of Texas Southwestern Medical Center [Dallas]
Subjects: Myocardial perfusion, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Ischemic heart disease, Mechanical Engineering, Computational Mechanics, Biomechanical modeling, Poroelasticity, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Computational physiology, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], Microvascular disease, Civil and Structural Engineering
Abstract: International audience; In this paper, we adapt a previously developed poromechanical formulation to model the perfusion of myocardium during a cardiac cycle. First, a complete model is derived in 3D. Then, we perform a dimensional reduction under the assumption of spherical symmetry and propose a numerical algorithm that enables us to perform simulations of the myocardial perfusion throughout the cardiac cycle. These simulations illustrate the use of the proposed model to represent various physiological and pathological scenarios, specifically the vasodilation in the coronary network (to reproduce the standard clinical assessment of myocardial perfusion and perfusion reserve), the stenosis of a large coronary artery, an increased vascular resistance in the microcirculation (microvascular disease) and the consequences of inotropic activation (increased myocardial contractility) particularly at the level of the systolic flow impediment. Our results show that the model gives promising qualitative reproductions of complex physiological phenomena. This paves the way for future quantitative studies using clinical or experimental data.
Published: 2022
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40. Quantification of left ventricular strain and torsion by joint analysis of 3D tagging and cine MR images

Author: Ezgi Berberoğlu, Christian T. Stoeck, Sebastian Kozerke, Martin Genet, Institute for Biomedical Engineering [ETH Zürich] (IBT), Universität Zürich [Zürich] = University of Zurich (UZH)-Department of Information Technology and Electrical Engineering [Zürich] (D-ITET), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Finite element method, Radiological and Ultrasound Technology, Swine, Heart Ventricles, Magnetic Resonance Imaging, Cine, Reproducibility of Results, Health Informatics, 3D tagging, Computer Graphics and Computer-Aided Design, Ventricular Function, Left, Predictive Value of Tests, Image Interpretation, Computer-Assisted, cardiovascular system, Humans, Animals, Radiology, Nuclear Medicine and imaging, cardiovascular diseases, Computer Vision and Pattern Recognition, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Cardiac magnetic resonance imaging, Image registration, circulatory and respiratory physiology
Abstract: International audience; Cardiovascular magnetic resonance (CMR) imaging is the gold standard for the noninvasive assessment of left-ventricular (LV) function. Prognostic value of deformation metrics extracted directly from regular cine CMR images has been shown by numerous studies in the clinical setting, but with some limitations to detect torsion of the myocardium. Tagged CMR introduces trackable features in the myocardium that allow for the assessment local myocardial deformation, including torsion; it is, however, limited in the quantification of radial strain, which is a decisive metric for assessing the contractility of the heart. In order to improve cine-only and tagged-only approaches, we propose to combine the advantages of both image types by fusing global shape motion obtained from cine images with the local deformation obtained from tagged images. To this end, tracking is first performed on cine images, and subsequently, the resulting motion is utilized to mask and track tagged data. Our implementation is based on a recent finite element-based motion tracking tool with mechanical regularization. Joint cine and tagged images registration performance is assessed based on deformation metrics including LV strain and twist using human and in-house porcine datasets. Results show that joint analysis of cine and 3DTAG images provides better quantification of LV strain and twist as either data source alone.
Published: 2022
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41. Exploitation conjointe d'un modèle biomécanique patient-spécifique de coeur et vaisseaux et de données mesurées au bloc opératoire pour augmenter le monitorage hémodynamique des patients sous anesthésie générale

Author: Le Gall, Arthur, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Hôpital Lariboisière-Fernand-Widal [APHP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Institut Polytechnique de Paris (IP Paris), Institut polytechnique de Paris, Dominique Chapelle, Radomir Chabiniok, Etienne Gayat, École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Institut Polytechnique de Paris, Étienne Gayat, and STAR, ABES
Subjects: Time-varying elastance, Monitorage cardiovasculaire, [PHYS.MECA.BIOM] Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Cardiac biomechanical modelling, Modélisation biomécanique cardiaque, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Relation pressionvolume en diastole (EDPVR), Calibration patient-spécifique, Élastance variable, Relation pression-volume en diastole (EDPVR), [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Noradrenaline haemodynamic effects, [SDV.MHEP.CSC] Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, Effets hémodynamique de la Noradrénaline, Cardiovascular monitoring, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, End-diastolic pressure-volume relationship (EDPVR), [INFO.INFO-MO] Computer Science [cs]/Modeling and Simulation, Patient-specific calibration, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph]
Abstract: Haemodynamic evaluation of anaesthetised patients in operating theatre or in intensive care units can be challenging. Indeed, monitoring devices can be inaccurate and/or invasive. Physicians have to evaluate the usefulness of the information given by the monitor, and its potential harms linked to its invasiveness before implementing the technique. Modelling methods may be an interesting alternative to improve the risk/benefit balance for the patients.Biomechanical modelling of heart and vessels as presented in this PhD thesis, when turned into patient-specific regime using patients' data measured in operating theatre, can allow simulation of cardiovascular physiology, including pressure-volume relationships through the cardiac cycle.In 45 patients undergoing general anaesthesia, we analysed the haemodynamic profile in terms of cardiac bioenergetics or ventricular arterial coupling, and we were able to evaluate the effects of Noradrenaline administered for 16 hypotensive patients, on cardiac efficiency, using pressure-volume loops estimated from a patient-specific biomechanical model.Our approach is original as it is based on a rigorous cardiovascular physiological description and on continuum mechanics theory allowing physical and physiological interpretation of the modelling results.This PhD thesis presents also original methods for model calibration, from limited data availability. We developed a passive constitutive law (end-diastolic pressure-volume relationship -- EDPVR) estimation method which reunites the biomechanical approach, usually difficult to implement in clinical settings, and the phenomenological approach, more efficient but less rigorous.We also explored the potentials of a time-varying elastance model, derived from the full biomechanical model. We demonstrated that for reasonable variation ranges, the time-varying elastance model could be used as a surrogate for the biomechanical model. This approach improves the computational time and resources, allowing to consider the transfer of our approach in real-time monitoring conditions.This PhD thesis is a proof of concept of the coupling between biomechanical modelling of heart and vessels and data measured in operating theatre to augment cardiovascular monitoring in anaesthetised patients. This is also the first step toward transfer of the method from bench to bedside., L'évaluation hémodynamique des patients sous anesthésie générale est une tache complexe pour les médecins anesthésistes et/ou réanimateurs. En effet, les techniques de monitorage sont imparfaites, imprécises et/ou invasives, et le choix de la technique de monitorage doit prendre en compte la délicate balance entre l'utilité attendue de l'information recueillie, et l'invasivité et l'imprécision de la méthode utilisée pour recueillir cette information. Les méthodes numériques peuvent représenter une alternative intéressante en améliorant ce rapport bénéfice/risque pour le patient.En particulier, la modélisation biomécanique de coeur et vaisseaux présentée dans cette thèse, une fois calibrée sur les données mesurées couramment au bloc opératoire, peuvent permettre de simuler, entre-autres, un cathétérisme cardiaque gauche. Nous avons ainsi pu analyser le profil hémodynamique de 45 patients sous anesthésie générale, et interpréter les effets de la Noradrénaline administré pour corriger une hypotension artérielle chez 16 patients, en termes de bioénergétique cardiaque, et de couplage ventriculo-aortique, à partir de boucles pression-volume ventriculaires simulées.Notre approche est originale car elle s'intègre dans une démarche rigoureuse basée sur la physiologie cardiovasculaire et la mécanique des milieux continus permettant ainsi de conserver une signification physique et physiologique aux résultats de la modélisation.Cette thèse présente également des méthodes originales, permettant de calibrer le modèle à partir d'une quantité limitée d'information mesurée chez les patients.Ainsi, nous avons mis au point des méthodes d'estimation des paramètres de la loi passive de comportement du coeur en diastole (relation pression-volume en diastole -- EDPVR), réunissant l'approche biomécanique, difficile à mettre en oeuvre en clinique, et l'approche phénoménologique, plus efficace mais moins rigoureuse.Nous avons également exploré les potentialités d'un modèle d'élastance variable, dérivé du modèle biomécanique. Nous avons pu montrer que dans une gamme de variation raisonnable, le modèle d'élastance variable pouvait être utilisé en lieu et place du modèle biomécanique, permettant d'envisager l'utilisation de notre approche dans des conditions de monitorage pour lesquelles l'estimation en temps réel est un enjeu important.Cette thèse représente une preuve de concept de l'exploitation conjointe des données mesurées couramment au bloc opératoire et d'un modèle biomécanique de coeur et vaisseaux pour augmenter le monitorage hémodynamique des patients sous anesthésie générale. Elle représente également la première étape du transfert de la méthode vers la pratique clinique.
Published: 2021

42. Coupling reduced-order blood flow and cardiac models through energy-consistent strategies: modeling and discretization

Author: Sébastien Imperiale, François Kimmig, Federica Caforio, Philippe Moireau, Jessica Manganotti, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Karl-Franzens-Universität Graz, École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, and Institute of Mathematics and Scientific Computing, University of Graz
Subjects: Work (thermodynamics), Reduced-order models, Heart models, Discretization, Quantitative Biology::Tissues and Organs, 0206 medical engineering, 02 engineering and technology, 030204 cardiovascular system & hematology, Energy-preserving time-scheme, Reduced order, Systems engineering, Cardiovascular modelling, 03 medical and health sciences, Arterial segment, TA168, 0302 clinical medicine, Computational Science and Engineering, Engineering (miscellaneous), Physics, Coupling, Applied Mathematics, Mechanics of engineering. Applied mechanics, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Mechanics, Blood flow, TA349-359, Dicrotic notch, 020601 biomedical engineering, Computer Science Applications, Shallow-water models, Ageing, Modeling and Simulation, Energy (signal processing), [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract: In this work we provide a novel energy-consistent formulation for the classical 1D formulation of blood flow in an arterial segment. The resulting reformulation is shown to be suitable for the coupling with a lumped (0D) model of the heart that incorporates a reduced formulation of the actin-myosin interaction. The coupling being consistent with energy balances, we provide a complete heart-circulation model compatible with thermodynamics hence stable numerically and informative physiologically. These latter two properties are verified by numerical experiments.
Published: 2021
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43. Altered Aortic Hemodynamics and Relative Pressure in Patients with Dilated Cardiomyopathy

Author: David Marlevi, Jorge Mariscal-Harana, Nicholas S. Burris, Julio Sotelo, Bram Ruijsink, Myrianthi Hadjicharalambous, Liya Asner, Eva Sammut, Radomir Chabiniok, Sergio Uribe, Reidar Winter, Pablo Lamata, Jordi Alastruey, David Nordsletten, Massachusetts Institute of Technology (MIT), King‘s College London, Department of Mathematics - University of Michigan, University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Universidad de Valparaiso [Chile], Pontificia Universidad Católica de Chile (UC), University of Cyprus (UCY), University of Bristol [Bristol], University of Texas Southwestern Medical Center [Dallas], Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, Division of Rehabilitation Medicine, Stockholm, Sweden, University of Michigan System, University of Cyprus [Nicosia] (UCY), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Danderyds sjukhus = Danderyd University Hospital
Subjects: 4D flow MRI, Cardiomyopathy, Dilated, Aortic hemodynamics, Aortic relative pressure, Heart Ventricles, Dilated cardiomyopathy, Aortic stiffness, Hemodynamics, Pharmaceutical Science, 030204 cardiovascular system & hematology, Magnetic Resonance Imaging, Ventricular Function, Left, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Genetics, cardiovascular system, Molecular Medicine, Humans, [SDV.IB]Life Sciences [q-bio]/Bioengineering, Cardiology and Cardiovascular Medicine, Genetics (clinical), Aorta
Abstract: Ventricular-vascular interaction is central in the adaptation to cardiovascular disease. However, cardiomyopathy patients are predominantly monitored using cardiac biomarkers. The aim of this study is therefore to explore aortic function in dilated cardiomyopathy (DCM). Fourteen idiopathic DCM patients and 16 controls underwent cardiac magnetic resonance imaging, with aortic relative pressure derived using physics-based image processing and a virtual cohort utilized to assess the impact of cardiovascular properties on aortic behaviour. Subjects with reduced left ventricular systolic function had significantly reduced aortic relative pressure, increased aortic stiffness, and significantly delayed time-to-pressure peak duration. From the virtual cohort, aortic stiffness and aortic volumetric size were identified as key determinants of aortic relative pressure. As such, this study shows how advanced flow imaging and aortic hemodynamic evaluation could provide novel insights into the manifestation of DCM, with signs of both altered aortic structure and function derived in DCM using our proposed imaging protocol. Graphic Abstractr
Published: 2021
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44. A relaxed growth modeling framework for controlling growth-induced residual stresses

Author: Martin Genet, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Relaxation, Finite element method, Computer science, Finite Element Analysis, Biophysics, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph], Decomposition analysis, Residual stresses, 03 medical and health sciences, 0302 clinical medicine, Residual stress, Humans, Orthopedics and Sports Medicine, Models, Cardiovascular, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Internal pressure, Arteries, 030229 sport sciences, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Elasticity, Biomechanical Phenomena, Transformation (function), Stress, Mechanical, Relaxation (approximation), Biological system, Finite growth, 030217 neurology & neurosurgery
Abstract: International audience; Background. Constitutive models of the mechanical response of soft tissues have been established and are widely accepted, but models of soft tissues remodeling are more controversial. Specifically for growth, one important question arises pertaining to residual stresses: existing growth models inevitably introduce residual stresses, but it is not entirely clear if this is physiological or merely an artifact of the modeling framework. As a consequence, in simulating growth, some authors have chosen to keep growth-induced residual stresses, and others have chosen to remove them.Methods. In this paper, we introduce a novel “relaxed growth” framework allowing for a fine control of the amount of residual stresses generated during tissue growth. It is a direct extension of the classical framework of the multiplicative decomposition of the transformation gradient, to which an additional sub-transformation is introduced in order to let the original unloaded configuration evolve, hence relieving some residual stresses. We provide multiple illustrations of the framework mechanical response, on time-driven constrained growth as well as the strain-driven growth problem of the artery under internal pressure, including the opening angle experiment.Findings. The novel relaxed growth modeling framework introduced in this paper allows for a better control of growth-induced residual stresses compared to standard growth models based on the multiplicative decomposition of the transformation gradient.Interpretation. Growth-induced residual stresses should 1 be better handled in soft tissues biomechanical models, especially in patient-specific models of diseased organs that are aimed at augmented diagnosis and treatment optimization.
Published: 2019
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45. A fully equilibrated microsphere model with damage for rubberlike materials

Author: Julie Diani, P. Le Tallec, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Materials science, Styrene-butadiene, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, 010305 fluids & plasmas, chemistry.chemical_compound, rubber material, Natural rubber, 0103 physical sciences, constitutive behavior, Composite material, Softening, Mechanical Engineering, Isotropy, anisotropic material, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], 021001 nanoscience & nanotechnology, Condensed Matter Physics, Mullins softening, chemistry, finite strain, Mechanics of Materials, Hyperelastic material, Finite strain theory, visual_art, Weight distribution, visual_art.visual_art_medium, Affine transformation, 0210 nano-technology
Abstract: International audience; A non-affine microsphere model for rubberlike materials is proposed, based on a local minimization of the network free energy under a maximal advance path constraint. It accounts for any chain weight distribution and for damage such as Mullins softening observed in filled rubber materials. The non-affine equal-force model is compared to the common affine model and a hybrid equal-force model from the literature, when considering the isotropic hyperelastic behavior without damage of rubber materials presenting chains of various lengths. The non-affine model shows an improved deformability compared to the affine model limited by the maximal extension of the shorter chains and a significantly softer behavior. Possible damage is introduced by increasing the chain lengths according to the submitted maximal chain traction force. Each chain are impacted independently resulting in a directional softening that introduces the evolution of the stress-free configuration that needs to be assessed over the loadings. The model was successfully tested on the cyclic uniaxial tension stretch-stress responses of carbon-black filled styrene butadiene rubbers that were well fitted with three parameters only.
Published: 2019
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46. Modelling the fluid–structure interactions of a capsule using a nonlinear thin shell model: Effect of wall thickness

Author: Dupont, C., Vidrascu, M., Le Tallec, P., Barthès-Biesel, D., Salsac, A.-V., Biomécanique et Bioingénierie (BMBI), Université de Technologie de Compiègne (UTC)-Centre National de la Recherche Scientifique (CNRS), COmputational Mathematics for bio-MEDIcal Applications (COMMEDIA), Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Mécanique des Structures (LMS), Université Tahri Mohamed Bechar [Bechar], Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), This work received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant agreement No. ERC-2017-COG -MultiphysMicroCaps)., Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Physics::Fluid Dynamics, Microcapsules, Mechanical Engineering, Numerical simulations, Shell, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Fluid-structure interactions
Abstract: International audience; We address the question of the modelling of the fluid-structure interactions for a microcapsule enclosed by a finite-thickness wall, and of the prediction of the buckling behaviour when it is subjected to large displacements and deformations. Specifically, we model the strong coupling between the solid (the wall dynamics) and fluid (the flow inside and outside the capsule) mechanics, for a wall material that can be strain-hardening or softening, while accounting for the bending resistance due to thickness. The fluid flow is assumed to be inertialess on the capsule scale, which allows the use of the boundary integral formulation for the fluid velocity. We discuss the different simplifications that are made when designing a fluid-shell interaction model for large deformations, and present a shear-membrane-bending (SMB) shell model that allows for a nonlinear wall stretching law. The performance of the model, as compared to a simple membrane model where bending resistance is neglected, is illustrated on a generic example: we consider an initially ellipsoidal capsule, freely suspended in a plane hyperbolic flow, that is subjected to such stringent deformation, that its short axis becomes the long one. We show that the simple membrane model predicts reasonably well the overall shape of the capsule, but cannot capture the detailed post buckling behaviour, for which a robust shell model is necessary. The SMB shell model complies with dominant membrane effects, remains stable even under large deformation and avoids numerical locking. It allows predicting post-buckling behaviour, which depends on the material constitutive law.
Published: 2022
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47. Asymptotic analysis of abstract two-scale wave propagation problems

Author: Imperiale, Sébastien, Université Paris-Saclay, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Asymptotic analysis, Operator theory, Wave equation, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP]
Abstract: This work addresses the mathematical analysis, by means of asymptotic analysis, of linear wave propagation problems involving two scales, represented by a single small parameter, and written in an abstract setting. This abstract setting is defined using linear operators in Hilbert spaces and also enters the framework of semi-group theory. In this setting, we show, under some assumptions on the structure of the wave propagation problems, weak and strong convergence of solutions with respect to the small parameter towards the solution of a well-defined limit problem.
Published: 2021

48. Hierarchical modeling of length-dependent force generation in cardiac muscles and associated thermodynamically-consistent numerical schemes

Author: Dominique Chapelle, Philippe Moireau, François Kimmig, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Computer science, Computational Mechanics, Ocean Engineering, Context (language use), multi-scale modeling, Sarcomere, biomechanics, 03 medical and health sciences, Myosin head, 0302 clinical medicine, numerical methods, 030304 developmental biology, 0303 health sciences, Frank–Starling law of the heart, Hierarchical modeling, Applied Mathematics, Mechanical Engineering, Numerical analysis, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Cardiac modeling, Multiscale modeling, multiscale modeling, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Computational Mathematics, Computational Theory and Mathematics, Coupling (computer programming), Frank-Starling mechanism, sarcomere, Biological system, 030217 neurology & neurosurgery, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract: International audience; In the context of cardiac muscle modeling, the availability of the myosin heads in the sarcomeres varies over the heart cycle contributing to the Frank-Starling mechanism at the organ level. In this paper, we propose a new approach that allows to extend the Huxley'57 muscle contraction model equations to incorporate this variation. This extension is built in a thermodynamically consistent manner, and we also propose adapted numerical methods that satisfy thermodynamical balances at the discrete level. Moreover, this whole approach-both for the model and the numerics-is devised within a hierarchical strategy enabling the coupling of the microscopic sarcomere-level equations with the macroscopic tissue-level description. As an important illustration, coupling our model with a previously proposed simplified heart model, we demonstrate the ability of the modeling and numerical framework to capture the essential features of the Frank-Starling mechanism.
Published: 2021
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49. Multiscale experimental and theoretical investigation of the structure-property relationships in the myocardium

Author: Tueni, Nicole, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Institut Polytechnique de Paris, Jean-Marc Allain, Martin Genet, Ecole polytechnique, École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Multiscale, Propriétés mécaniques, Mechanical properties, Etude multi échelle, Biomécanique, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], Étude Multi-Échelle, Multiscale study, [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], Heart tissue, Biomechanics, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Microstructure, Tissu cardiaque, Cardiac tissue
Abstract: The myocardium is a complex tissue, primarily made of cardiac cells and extra-cellular collagenous matrix, arranged in a hierarchical microstructure. This microstructure evolves with time, either physiologically or pathologically, altering the macroscopic mechanical properties of heart, hence its function. The objective of this PhD thesis is to improve our understanding of the structure-properties relationships in the cardiac tissue by focusing on the role of mesostructure, called the sheetlet, on the macroscopic mechanical properties. In a first part, a literature review of the existing literature on the role of sheetlet is performed. In the second chapter, we present an experimental setup we developed, combining a full-field Mueller polarimetric imager and an in-situ traction device with a local measure of the deformation during sample stretch. We observe a global cohesion of the tissue apart on separation lines at the mesoscale, that tend to open under traction. We hypothesize that these lines are the collageneous layers separating the sheetles, bundles of cardiomyocytes surrounded by layers of perimysial collagen. In the third chapter, we propose a simple optical method combined with a fast image analysis to extract the sheetlet local orientation on left ventricle slices, in order to construct a 3D mapping of the sheetlet organization in the heart. In the second part of the PhD thesis (chapter four), we propose a multiscale model of the myocardium aiming at determining the structural origin of the observed macroscale mechanical anisotropy. Indeed, the observed orthotropy can be due either to the rotation of the cell orientation, or to the presence of the mesoscale collageneous layers. We design three mesostructures made of different configurations of cardiomyocytes and collagen. The mechanical response of these mesostructures are homogenized with numerical periodic homogenization, and the obtained material parameters are used in a macroscopic simulation of a shear experiment. The comparison between our results and the experimental data show that the collagen layers are necessary to reproduce the material orthotropy. The final chapter of this thesis presents some perspectives of this work.; Le myocarde est un tissu complexe, principalement constitué de cellules cardiaques et d'une matrice collagénique extracellulaire, disposés selon une microstructure hiérarchique. Cette microstructure évolue au cours du temps, de manière physiologique ou pathologique, altérant les propriétés mécaniques macroscopiques du cœur, donc sa fonction. L'objectif de cette thèse est d'améliorer notre compréhension des relations structure-propriétés dans le tissu cardiaque en s'intéressant au rôle de la mésostructure, appelée feuillet, sur les propriétés mécaniques macroscopiques. Dans une première partie, une revue de la littérature existante sur le rôle du feuillet est réalisée. Dans le deuxième chapitre, nous présentons un montage expérimental que nous avons développé, combinant un imageur polarimétrique Mueller plein champ et un dispositif de traction in-situ avec une mesure locale de la déformation lors de l'étirement de l'échantillon. On observe une cohésion globale des tissus à part sur des lignes de séparation à mésoéchelle, qui ont tendance à s'ouvrir sous traction. Nous émettons l'hypothèse que ces lignes sont les couches collagéniques séparant les feuillets, des faisceaux de cardiomyocytes entourés de couches de collagène périmysial. Dans le troisième chapitre, nous proposons une méthode optique simple combinée à une analyse d'image rapide pour extraire l'orientation locale des feuillets sur des coupes de ventricule gauche, afin de construire une cartographie 3D de l'organisation des feuillets dans le cœur. Dans la deuxième partie de la thèse (chapitre quatre), nous proposons un modèle multi-échelle du myocarde visant à déterminer l'origine structurale de l'anisotropie mécanique macro-échelle observée. En effet, l'orthotropie observée peut être due soit à la rotation de l'orientation des cellules, soit à la présence des couches collagéniques méso-échelle. Nous concevons trois mésostructures constituées de différentes configurations de cardiomyocytes et de collagène. La réponse mécanique de ces mésostructures est homogénéisée avec une homogénéisation périodique numérique, et les paramètres de matériau obtenus sont utilisés dans une simulation macroscopique d'une expérience de cisaillement. La comparaison entre nos résultats et les données expérimentales montre que les couches de collagène sont nécessaires pour reproduire l'orthotropie du matériau. Le dernier chapitre de ce manuscrit présente quelques perspectives de ce travail.
Published: 2021

50. Model-Assisted Time-Synchronization of Cardiac MR Image and Catheter Pressure Data

Author: Mohamed Abdelghafar Hussein, Maria Gusseva, Radomir Chabiniok, Surendranath R. Veeram Reddy, Gerald F. Greil, Daniel A. Castellanos, Joshua S. Greer, Tarique Hussain, Dominique Chapelle, Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine (M3DISIM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), University of Texas Southwestern Medical Center [Dallas], Boston Children's Hospital, Pediatric department, Kafrelsheikh University, Kafrelsheikh University, École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, and Faculty of Medicine, Kafrelsheikh University, Kafrelsheikh, Egypt
Subjects: Physics, cardiovascular modeling, time-synchronization of clinical data, medicine.diagnostic_test, Cardiac cycle, pressure volume loops, Image (category theory), Magnetic resonance imaging, personalized medicine, 030204 cardiovascular system & hematology, Type (model theory), 030218 nuclear medicine & medical imaging, 03 medical and health sciences, QRS complex, 0302 clinical medicine, Nuclear magnetic resonance, translational research, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, Norm (mathematics), Ventricular pressure, medicine, [SDV.IB]Life Sciences [q-bio]/Bioengineering, interventional cardiovascular magnetic resonance imaging, Volume (compression)
Abstract: International audience; When combining cardiovascular magnetic resonance imaging (CMR) with pressure catheter measurements, the acquired imageand pressure data need to be synchronized in time. The time offset between the image and pressure data depends on a number of factors,such as the type and settings of the MR sequence, duration and shape of QRS complex or the type of catheter, and cannot be typically estimated beforehand. In the present work we propose using a biophysical heart model to synchronize the left ventricular (LV) pressure and volume (P-V) data. Ten patients, who underwent CMR and LV catheterization, were included. A biophysical model of reduced geometrical complexity with physiologically substantiated timing of each phase of the cardiac cycle was first adjusted to individual patients using basic morphological and functional indicators. The pressure and volume waveforms simulated by the patient-specific models were then used as templates to detect the time offset between the acquired ventricular pressure and volume waveforms. Time-varying ventricular elastance was derived from clinical data both as originally acquired as well as when time-synchronized, and normalized with respect to end-systolic time and maximum elastance value$E^N_\text {orig}(t)$, $E^N_\text {t-syn}(t)$, respectively). $E^N_\text {t-syn}(t)$ was significantly closer to the experimentally obtained $E^N_\text {exp}(t)$ published in the literature (p < 0.05, $L^2$ norm). The work concludes that the model-driven time-synchronization of P-V data obtained by catheter measurement and CMR allows to generate high quality P-V loops, which can then be used for clinical interpretation.
Published: 2021
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