Saleheen H I, Ng K T
National Applied Software Engineering Center, Johnstown, PA, USA.
IEEE Trans Biomed Eng. 1998 Jan;45(1):15-25. doi: 10.1109/10.650347.
Bidomain modeling of cardiac tissues provides important information about various complex cardiac activities. The cardiac tissue consists of interconnected cells which form fiber-like structures. The fibers are arranged in different orientations within discrete layers or sheets in the tissue, i.e., the fibers within the tissue are rotated. From a mathematical point of view, this rotation corresponds to a general anisotropy in the tissue's conductivity tensors. Since the rotation angle is different at each point, the anisotropic conductivities also vary spatially. Thus, the cardiac tissue should be viewed as an inhomogeneous anisotropic structure. In most of the previous bidomain studies, the fiber rotation has not been considered, i.e., the tissue has been modeled as a homogeneous orthotropic medium. In this paper, we describe a new finite-difference bidomain formulation which accounts for the fiber rotation in the cardiac tissue and hence allows a more realistic modeling of the cardiac tissue. The formulation has been implemented on the data-parallel CM-5 which provides the computational power and the memory required for solving large bidomain problems. Details of the numerical formulation are presented together with its validation by comparing numerical and analytical results. Some computational performance results are also shown. In addition, an application of this new formulation to provide activation patterns within a tissue slab with a realistic fiber rotation is demonstrated.
心脏组织的双域建模提供了有关各种复杂心脏活动的重要信息。心脏组织由相互连接的细胞组成，这些细胞形成纤维状结构。纤维在组织中的离散层或片中以不同方向排列，即组织内的纤维是旋转的。从数学角度来看，这种旋转对应于组织电导率张量中的一般各向异性。由于旋转角度在每个点都不同，各向异性电导率也随空间变化。因此，心脏组织应被视为非均匀各向异性结构。在大多数先前的双域研究中，未考虑纤维旋转，即组织被建模为均匀正交各向异性介质。在本文中，我们描述了一种新的有限差分双域公式，该公式考虑了心脏组织中的纤维旋转，从而能够对心脏组织进行更逼真的建模。该公式已在数据并行的CM - 5上实现，CM - 5提供了解决大型双域问题所需的计算能力和内存。给出了数值公式的详细信息以及通过比较数值结果和分析结果进行的验证。还展示了一些计算性能结果。此外，演示了这种新公式在具有实际纤维旋转的组织平板内提供激活模式的应用。
