Rapidly generate lumbar spine volume mesh

Shenghui Liao, Ruofeng Tong, Minke Wang, Jinxiang Dong

Abstract: This paper presents a new method for rapidly generating accurate patient-specific lumbar spine volume mesh for finite element analysis. First, initial isosurface of the vertebral body is extracted from CT volume data. Then, a series of non-parallel "best cross-section planes" are placed semi-automatic ally according to the morphologic characteristic of surface model, forming a "non-regular piecewise subspace". This subspace and the embedded surface model are transformed to a "regular subspace" covered by a regular structure grid. Based on the information from the 2D contours of warped surface model, the "structure grid contours" are generated, from which a surface mesh of high quality is generated. At the same time, these grid nodes inside of the surface mesh are recorded as insertion points, and the tetrahedral volume mesh is created quickly by a boundary constrained Delaunay triangulation procedure in the "regular subspace". Finally a two-step reverse transform procedure is employed to recover the shape feature of the lumbar volume mesh in the original three-dimensional space, achieving a smooth change of element size transition.