角膜移植中缝针刺入角膜的有限元仿真  

Finite Element Simulation of Needle Insertion into Cornea

作　　者：杨洋[1] 刘笑宇[1] 符浩[1] 

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100083

出　　处：《机械工程学报》2008年第12期24-29,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(50675008)

摘　　要：利用微力材料试验机进行新鲜猪眼球角膜组织的力学性能测试试验。试验选用医用眼科2号缝针(直径0.2 mm),以1mm/s的临床手术平均刺入速度,在正常眼压下刺入角膜组织,得到了缝针针尖在刺入过程中的位移一针轴力关系。在此基础上,采用线性三角形单元建立角膜的平面有限元分析模型,并根据缝针与角膜软组织接触表面间相互作用的粘—滑理论,建立缝针刺入角膜的有限元仿真算法。以试验测得的针尖位移和针轴力的关系为边界条件,在Matlab环境下利用迭代算法对所建立的有限元方程进行求解,实现了缝针刺入角膜过程的实时仿真,同时得到缝针刺入角膜过程中节点的位移图和位移—针轴力的关系曲线,为角膜移植手术机器人的设计和缝合作业的任务规划提供了重要的依据。Mechanical properties during needle puncturing cornea are tested by using a micro-force material tester. The relationship between displacement and axial force is obtained for No.2 suturing needle under normal intraocular pressure, when the needle is puncturing cornea with a velocity of 1mm/s. A finite element model of needle puncturing cornea is established by linear triangular element, a new finite element algorithm of contact interaction between needle and cornea soft tissue is designed based on the theory of stick-slip. The relationship between displacement of needle-tip and needle-axial force obtained through testing is considered as boundary conditions, the iterative algorithm is used to solve the finite element simulation problem under the Matlab environment, needle puncturing cornea is successfully simulated in real-time. At the same time, the displacement drawing of needle-tip and the relation curve between displacement and needle axial force are numerically obtained. Compared with the testing results from experiment, the method is effective and significant for designing cornea-grafting robot and planning suturing manipulation.

关 键 词：有限元仿真 粘-滑模型 角膜移植 

分 类 号：TB115[理学—数学]