The FE-modeling of complex anatomical structures is not solved satisfyingly so far. Voxel-based as opposed to contour-based algorithms allow an automated mesh generation based on the image data. Nonetheless their geometric precision is limited.
We developed an automated mesh-generator that combines the advantages of voxel-based generation with improved representation of the geometry by displacement of nodes on the object-surface. Models of an artificial 3D-pipe-section and a skullbase were generated with different mesh-densities using the newly developed geometric, unsmoothed and smoothed voxel generators.
Compared to the analytic calculation of the 3D-pipe-section model the normalized RMS error of the surface stress was 0.173–0.647 for the unsmoothed voxel models, 0.111–0.616 for the smoothed voxel models with small volume error and 0.126–0.273 for the geometric models. The highest element-energy error as a criterion for the mesh quality was 2.61 × 10−2 N mm, 2.46 × 10−2 N mm and 1.81 × 10−2 N mm for unsmoothed, smoothed and geometric voxel models, respectively. The geometric model of the 3D-skullbase resulted in the lowest element-energy error and volume error. This algorithm also allowed the best representation of anatomical details.
The presented geometric mesh-generator is universally applicable and allows an automated and accurate modeling by combining the advantages of the voxel-technique and of improved surface-modeling.