Detailed models of the biomechanics of the heart are important both for developing improved interventions for patients with heart disease and also for patient risk stratification and treatment planning. For instance, stress distributions in the heart affect cardiac remodelling, but such distributions are not presently accessible in patients. Biomechanical models of the heart offer detailed three-dimensional deformation, stress and strain fields that can supplement conventional clinical data. In this work, we introduce dynamic computational models of the human left ventricle (LV) that are derived from clinical imaging data obtained from a healthy subject and from a patient with a myocardial infarction (MI). Both models incorporate a detailed invariant-based orthotropic description of the passive elasticity of the ventricular myocardium along with a detailed biophysical model of active tension generation in the ventricular muscle. These constitutive models are employed within a dynamic simulation framework that accounts for the inertia of the ventricular muscle and the blood that is based on an immersed boundary (IB) method with a finite element description of the structural mechanics. The geometry of the models is based on data obtained non-invasively by cardiac magnetic resonance (CMR). CMR imaging data are also used to estimate the parameters of the passive and active constitutive models, which are determined so that the simulated end-diastolic and end-systolic volumes agree with the corresponding volumes determined from the CMR imaging studies. Using these models, we simulate LV dynamics from enddiastole to end-systole. The results of our simulations are shown to be in good agreement with subject-specific CMR-derived strain measurements and also with earlier clinical studies on human LV strain distributions.

中文翻译：

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使用浸入式边界有限元方法对健康和疾病中的人类左心室进行动态有限应变建模。

心脏生物力学的详细模型对于开发针对心脏病患者的改进干预措施以及对患者风险分层和治疗计划均至关重要。例如，心脏中的压力分布会影响心脏重塑，但目前尚无法在患者体内获得。心脏的生物力学模型提供了详细的三维变形，应力和应变场，可以补充常规的临床数据。在这项工作中，我们介绍了人类左心室（LV）的动态计算模型，这些模型是根据从健康受试者和患有心肌梗塞（MI）的患者获得的临床影像数据得出的。两种模型都结合了对心室心肌被动弹性的基于不变式的详细正交异性描述以及在心室肌肉中产生主动张力的详细生物物理模型。这些本构模型在动态仿真框架内使用，该框架考虑了基于有限结构描述的浸入边界（IB）方法的心室肌肉和血液的惯性。模型的几何形状基于通过心脏磁共振（CMR）非侵入性获得的数据。CMR成像数据还用于估计被动本构模型和主动本构模型的参数，这些参数被确定为使模拟的舒张末期容积和收缩末期容积与从CMR成像研究确定的相应容积一致。使用这些模型，我们模拟了从舒张末期到收缩末期的左心室动力学。结果表明，我们的模拟结果与特定于受试者的CMR衍生应变测量结果以及人类LV应变分布的早期临床研究非常吻合。