腹腔机器人手术中操作力的准确计算，对改进手术力反馈，提高手术精度具有重要意义。本项目以腹腔手术器官中典型的超弹性体器官—肝脏器官为例，研究腹腔机器人手术操作力的定量描述。首先通过测量腹腔典型器官组织动态剪切模量建立超弹性模型，研究粘弹性系数对器官模型的影响。其次基于超弹性模型针对机器人手术操作典型动作（切割、穿刺）开展有限元计算分析，揭示手术操作力与组织剪切模量、刀具接触长度等参数的函数关系。最后，开展动物组织实验研究，验证机器人手术操作力拟合函数的有效性，为机器人手术的基础理论研究与临床应用提供理论模型基础与数据支撑。

Determination of haptic force in robotics surgery is of crucial importance to improve robotic control and surgery accuracy. Our goal is to come up with a quantitative description of the haptic force in robotics surgery. We will focus on the abdomen organs that have hyperelastic properties. We choose liver as a study example that demonstrates to be hyperelastic. We propose to use a shear-testing method to characterize tissue anisotropy and verify the isotropy hypothesis of the model. We will construct a hyperelastic material model with the measured mechanical properties of the liver tissue, and analyze the effect of viscoelastic parameters in the model. We will simulate typical surgical operations such as cutting and biopsy using finite element method, and analyze the operation force and corresponding parameters. We propose to use a function to describe the operation force. An animal model will be used to validate the fitted haptic force function. Theoretical analysis and experiment data from this study will benefit the research and clinical community of robotics surgery.