Soft tissue deformation method based on finite element model of octree mesh

Abstract

The invention provides a soft tissue deformation method based on a finite element model of an octree mesh. The method comprises: drawing a three-dimensional model of soft tissue, constructing a plurality of uniform hexahedral meshes based on the AABB method, and generating an octree mesh based on the mesh generation algorithm of an octree based on the hexahedral mesh, modeling the hexahedron meshby the finite element method, solving the deformation process of the soft tissue, assembling the element stiffness matrixes on adjacent element nodes into the total stiffness matrix of the discrete domain, solving the dynamic equilibrium differential equation for each matrix by time integral under dynamic equilibrium, to obtain the displacement of the nodes with time, and displaying the stress deformation of the soft tissue by the rendering of the displacement of the nodes. The method realistically simulates the process of tension deformation of the soft tissue epidermis of any shape in virtual surgery, has high real-time performance, reduces the calculation amount, and solves the problem that the number of finite element meshes is complicated and the soft tissue deformation process cannotbe simulated in real time.

Description

technical field [0001] The invention relates to the field of virtual surgery simulation, in particular to a soft tissue deformation method based on a finite element model of an octree grid. Background technique [0002] Traditional clinical medicine usually uses rubber mannequins and living organisms such as human cadavers, mice, and frogs as surgical training objects. The rubber mannequin has simple structure and single function, and there are errors in the degree of simulation; the material activity of human corpses is quite different from that of living tissues, and the reusability is low. With the development of our society, it is becoming more and more difficult to obtain corpses; The physiological structure of the human body is different, so it is not accurate as an object of clinical surgery training. At the same time, there are many moral problems such as persecuting animals. [0003] With the improvement of computer hardware processing performance, virtual surgery ...

AI Technical Summary

Problems solved by technology

At present, the commonly used soft tissue deformation methods can be divided into three categories from the perspective of physical calculation models: the first category, the simulation method based on the finite element method, can simulate the deformation of soft tissue realistically because it includes the material properties of soft tissue, so that the accuracy of the results is high. However, the deformation calculation of finite element is based on a large number of grid cells, so the calculation cost is very high

The second type, position-based dynamics method, although the calculation speed is fast and there is no stability problem, the deformation effect it produces only seems to conform to the laws of physics, but not really conforms to the laws of physics

The third category is the meshless method, which is suitable for large deformation, but due to the dense sampling points, the calculation burden is relatively heavy

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