基于混合拓扑填充球模型的子宫软组织形变模拟方法  

Simulation Method for Uterus Soft-Tissue Deformation Based on Filled-Sphere Model with Hybrid Topology

作　　者：姜杉[1] 宋雨菲 杨志永[1] 曾静[2] Jiang Shan;Song Yufei;Yang Zhiyong;Zeng Jing(School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Department of Gynecologic Oncology,Tianjin Central Hospital of Gynecology Obstetrics,Tianjin 300071,China)

机构地区：[1]天津大学机械工程学院,天津300350 [2]天津市中心妇产科医院妇瘤科,天津300071

出　　处：《天津大学学报（自然科学与工程技术版）》2024年第11期1152-1160,共9页Journal of Tianjin University：Science and Technology

基　　金：国家重点研发计划资助项目(2022YFB4702600);国家自然科学基金资助项目(81871457);天津市卫生健康科研项目(ZC20111).

摘　　要：软组织形变模拟是虚拟手术领域中最为重要的研究内容之一.对于子宫等具有复杂生理结构的人体器官而言,实现其形变建模并达到模拟的实时性要求是目前存在的挑战.为了解决上述问题,本文提出了一种具有混合拓扑结构的填充球形变理论,构建了面向子宫等复杂生理结构器官的形变建模方法,实现了子宫肌瘤剔除手术背景下的子宫形变模拟.首先,提出了改进的填充球模型,针对器官部位几何表面的差异性,不同于以往单一拓扑的连接方式,设计了包含四面体拓扑和依据中轴线拓扑的混合填充球结构,并综合考虑子宫生理特性与手术特点,进行了形变模型区域性与软组织特性的细节化设计.在此基础上,提出了一种基于度量张量剖分方法的四面体拓扑填充球结构的建模方法,结合中轴线的提取,分别建立了相应子宫部位的拓扑结构,从而构建出完整的子宫填充球模型.通过OpenGL编写了子宫形变的虚拟环境,并结合3D Systems公司的Touch力反馈设备搭建子宫形变模拟平台,实现了子宫软组织的模拟变形.最后,设计与开展验证实验,测试子宫形变模拟的效果及实时性;另一方面,搭建了一套测量真实软组织形变数据的实验平台,对本研究实现的虚拟形变与真实软组织形变进行对比.实验结果表明:虚拟子宫形变的画面刷新频率集中在40~60 Hz范围内,满足了手术训练的实时性要求;在软组织所受作用力小于3 N的情况下,两者形变位移的最大差异为0.117 mm,同时形变模拟效果符合真实软组织在外力作用下的整体变形趋势.The simulation of soft-tissue deformation is an important area of research in the field of virtual surgery.For organs with complex physiological structures such as the uterus,realizing deformation modeling and real-time simulation poses a challenge.In response,this paper proposed a filled-sphere model with a hybrid topology.This method was tailored for modeling complex physiological structures,exemplified through its application in simulating uterine deformation during hysteromyomectomy procedures.First,an improved filled-sphere model was proposed,which was designed to accommodate the variability inherent in the geometric surfaces of organs.This model diverged from traditional single topology connection mode by integrating a hybrid filled-sphere structure that involves tetrahedral and central axis topologies.Further,considering uterine physiological properties and surgical operation characteristics,regional and soft-tissue characteristics were incorporated into the deformation model.On this basis,we introduced a modeling method with a filled-sphere structure and tetrahedral topology,leveraging the metric tensor partitionmethod. By extracting the central axis of geometric model,we simulated topological structures of different uterineparts,resulting in a complete filled-sphere model of the uterus. We developed a virtual environment for uterine deformationusing OpenGL. Moreover,using Touch from 3D Systems,a uterine-deformation simulation platform wasestablished. Subsequently,experiments were performed to validate the effectiveness and real-time performance of oursimulation. In addition,an experimental platform for measuring real soft-tissue deformation was developed to comparethe virtual deformation determined through simulations against actual soft-tissue deformation. Results show thatthe updating frequency of virtual uterine deformation is concentrated in the range of 40—60 Hz,meeting the realtimemonitoring requirements of surgical training. The maximum difference between virtual and actual deformations is0.117

关 键 词：虚拟手术 软组织形变 填充球模型 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]