虚拟肝脏重建与形变切割仿真-《中国医学物理学杂志》

文章信息/Info

Title:: Reconstruction of virtual liver and its deformation and cutting simulations

Author(s):: GAO Haiguo; JIA Shiyu; College of Computer Science and Technology, Qingdao University, Qingdao 266071, China

Keywords:: Keywords: liver anatomy model reconstruction surgical simulation soft tissue deformation simulation soft tissue cutting simulation

摘要:: 针对肝脏虚拟手术仿真对仿真场景逼真性、形变和切割仿真实时性的要求，提出虚拟体包络技术、基于解剖结构的边界条件设置以及双体素网格3种创新方法，根据肝脏的解剖结构重建肝脏仿真模型。对于肝脏模型外以面模型形式存在的管道模型，将其镶嵌在虚拟包络体模型中以实现形变和切割仿真。通过对肝脏表面解剖结构的分析，以及对肝脏约束形式进行合理简化，在肝脏韧带结构上设置边界限制标志。双体素网格方法在两层尺度不同的体素网格上重建肝脏仿真模型：原始模型表面在精细体素网格中重建，而切割面则在粗糙体素网格中构造，以此减少形变和切割仿真的计算量。仿真结果表明所用方法能在保持肝脏形变和切割仿真的真实感前提下提高仿真的运行速度。

Abstract:: Abstract: To meet the requirements of simulation scene fidelity and real-time performance of deformation and cutting for virtual liver surgery simulation, 3 novel methods are proposed, including virtual volume envelope method, boundary condition settings based on anatomical structures, and two-level linked voxel method. The liver model for simulation is reconstructed according to its actual anatomical structures. Extrahepatic vessels in the form of surface models are embedded in the virtual volume envelope model for realizing deformation and cutting simulations. Boundary conditions are set on the ligament structures of the liver according to the analysis on the anatomical structures of the liver surface and the appropriate simplifications of its boundary constraints. The two-level linked voxel method reconstructed the liver model for simulation in two linked voxel grids with different levels. The original surface mesh is reconstructed in a fine level linked voxel grid, while the cut surface mesh is constructed in a coarse level linked voxel grid for reducing the computational load of deformation and cutting simulations. Simulation results show that the proposed methods can improve the running speed of the liver deformation and cutting simulations while maintaining the realism.