Tetrahedral Meshes of the Heart Model

4. Tetrahedral Meshes of the Heart Model

Considering all the components in the simplified heart model as only one object. First convert the triangular surface mesh into volumetric data using signed distance method, then extract triangular surface meshes and tetrahedral meshes from it.

Heart Model with Valves and no Valve Gaps

(a) Viewed from the outside. (b) Inner structure (wireframe). (c) A cross section of the tetrahedral mesh of the heart.

Heart Model with Valve Gaps

In order to keep all of the features of the complicated human heart model (like valves, chambers and blood vessels) and at the same time minimize the number of elements for efficient finite element calculation, we choose adaptive tetrahedral meshes. The valve areas are set at the finest level, features based on the Eucliean error function are identified and preserved. Those areas with thin walls are refined to keep the correct topology. The following mesh is extracted from a signed distance function dataset with the resolution of 257^3.

Adaptive tetrahedral mesh for the heart model with valve gaps. The top row shows the boundary in wire frame, the meshes in valve areas are finest; The bottom left is viewed from outside; The bottom right shows a cross section of the adaptive tetrahedral mesh, the valves have finest mesh, features are identified using the Eucliean error function, and preserved by the mesh adaptivity.

Valves with Gaps in the Adaptive Mesh

(a) Aortic valve. (b) Tricuspid valve.
(c) Pulmonary valve. (d) Mitral valve.

Boundary Detection

Aortic valve. Tricuspid valve.
Pulmonary valve. Mitra valve.