中文摘要：

为解决人软组织系统物理建模过程中存在的精确性与实时性之间的矛盾，选择典型的人体软组织——肝脏为实验对象，建立了一套满足实时性的复杂软组织物理建模方法．首先在基于表面模型的质点-弹簧系统基础上引入了体弹簧，采用能够满足体行为模拟的质点-弹簧模型；在质点质量分配方面，采用体离散化的方法完成了质点质量的确定，同时提出了基于层次包围盒的重心修正方法；在弹簧参数设定方面，通过真实软组织生物力学实验和参数分析，提出分段线性化弹簧参数设定方法；最后提出了作用力影响范围的受力优化分析方法，以提升变形仿真的速度．实验结果表明，该方法能够更好地模拟软组织的形变，并提高模拟仿真的实时性．

英文摘要：

In soft tissue modeling, accuracy and real-time performance are two contradictory requirements. In this paper, we investigate an efficient physical modeling method for real-time simulation of human liver. To this end, volume spring is first introduced to simulate the volume behavior of liver based on a surface model of the mass-spring system. Volume discretization is then used to determine the mass of the mass points. Based on hierarchical bounding, a gravity correction method is also proposed to ensure the accuracy of the mass distribution. To determine the parameters of the springs used in the model, a piecewise linearization method is proposed based on biomechanics experiments on real soft tissue and parameter analysis. Stress analysis and optimization have also been conducted to improve the efficiency of deformation simulation. Experimental results show that the proposed methods perform well in simulating the deformation of soft tissues and also help to improve the real-time property of the simulation.