Modelling Thermo-Electro-Mechanical Effects in Orthotropic Cardiac Tissue  

作　　者：Ricardo Ruiz-Baier Alessio Gizzi Alessandro Loppini Christian Cherubini Simonetta Filippi 

机构地区：[1]Mathematical Institute,University of Oxford,Woodstock Road,Oxford OX26GG,United Kingdom [2]Laboratory of Mathematical Modelling,Institute of Personalised Medicine,Sechenov University,Moscow,Russian Federation [3]Nonlinear Physics and Mathematical Modeling,Department of Engineering,University Campus Bio-Medico of Rome,Via A.del Portillo 21,00128,Rome,Italy [4]International Center for Relativistic Astrophysics(ICRA),and ICRANet,Piazza delle Repubblica 10,I-65122 Pescara,Italy

出　　处：《Communications in Computational Physics》2020年第1期87-115,共29页计算物理通讯（英文）

基　　金：supported by the Engineering and Physical Sciences Research Council(EPSRC)through the research grant EP/R00207X。

摘　　要：In this paper we introduce a new mathematical model for the active contraction of cardiac muscle,featuring different thermo-electric and nonlinear conductivity properties.The passive hyperelastic response of the tissue is described by an orthotropic exponential model,whereas the ionic activity dictates active contraction in-corporated through the concept of orthotropic active strain.We use a fully incompressible formulation,and the generated strain modifies directly the conductivity mechanisms in the medium through the pull-back transformation.We also investigate the influence of thermo-electric effects in the onset of multiphysics emergent spatiotem-poral dynamics,using nonlinear diffusion.It turns out that these ingredients have a key role in reproducing pathological chaotic dynamics such as ventricular fibrillation during inflammatory events,for instance.The specific structure of the governing equations suggests to cast the problem in mixed-primal form and we write it in terms of Kirchhoff stress,displacements,solid pressure,dimensionless electric potential,activation generation,and ionic variables.We also advance a new mixed-primal finite element method for its numerical approximation,and we use it to explore the properties of the model and to assess the importance of coupling terms,by means of a few computational experiments in 3D.

关 键 词：Cardiac electromechanics orthotropic active strain thermo-electric coupling scroll wave propagation numerical simulations 

分 类 号：O34[理学—固体力学]