基于冷冻切片的人体腰椎三维有限元模型

目的利用上海交通大学生命质量与机械工程研究所自主开发的冷冻切片处理软件CryoSegmemation提取人体骨骼的边缘,利用逆向工程软件Imageware建立骨骼的面模型,在ANSYS中建立人体腰椎的三维有限元模型。方法利用第三军医大学的第一例男性冷冻切片数据进行图像处理,截面轮廓线信息处理。结果准确快速地建立了完全符合人体解剖特征的腰椎三维有限元模型。结论利用该研究所自主开发的冷冻切片软件和一些现有的商用软件可以准确、快速地建立人体腰椎的三维面模型、体模型及有限元模型,为航空、车辆、船舶、生物医学工程等不同的领域进行数值模拟计算和动力学仿真提供完全符合人体解剖学特征的原始模型。     

基于虚拟人数据的心脏表面模型三维重建及显示

基于美国虚拟人一号数据,利用Rhino软件建立心脏模型,用VCH和Direct3D编程实现心脏模型的三维交互显示。结果表明,该方法所建模型较逼真,对模型的可控制性强,能满足心肌缺血定位和可视化显示研究的需要。     

基于数据库的交互式人体解剖三维图谱系统

目的:基于虚拟中国人男性一号三维结构模型数据库,采用Browser/Server结构,构建交互式多用户人体解剖三维图谱系统,发布和共享三维模型数据。方法:根据用户交互表单,系统从数据库获取模型信息,以虚拟中国人模型数据为材料,在服务器端动态组合,生成需要的VRML人体模型,并在客户端浏览器中交互显示;以MeSH为基础,按照人体生理结构的命名体系和层次,建立模型数据库,并以XML的形式发布。结果:实现了三维模型在线交互式浏览,直观地发布结构数据;构建了数据中间层,实现标准化的数据共享和扩展。结论:图谱系统提供了直观的数据可视化,构建了符合MeSH标准的模型数据体系,为人体解剖结构的学习和研究带来了方便,为远程解剖教学提供了重要平台。     

基于无网格的软组织切割模型的研究进展

具备支持实时交互能力的软组织切割模型对于虚拟手术仿真系统具有至关重要的意义。传统的软组织切割模型多基于网格建立,将软组织切割过程建模为手术刀具与软组织几何模型之间的网格切割计算,并在此基础上建立和求解生物力学方程以描述切割过程。由于网格切割计算代价高且软组织切割过程中涉及到复杂的生物力学问题,很难实现实时交互,严重影响了虚拟手术仿真效果。与此相反,基于无网格的软组织切割模型打破了网格限制,在触觉/视觉逼真度和实时性方面都具有很大优势。文中从力反馈和视觉反馈的渲染质量和速度等方面,就基于无网格的软组织切割模型的研究现状进行了概述,对存在的问题进行了分析和总结,并对未来的发展方向进行展望。     

构建基于正常人心脏解剖及影像数据的动态心脏模型

目的　构建基于正常心脏数据的三维动态心脏模型。 方法　采集正常成人心脏数据,通过Microsoft Visual C++和3DMax软件重建生成心脏三维模型,并将正常心电图与之整合,同步显示心脏运动。 结果　建立了数字化心脏可视动态模型,能够反映心脏三维形状和内腔结构,并可与心电图同步运动。 结论　动态心脏模型能够为心脏结构与运动的教学及疾病分析提供可视化的数值仿真平台。     

基于格子Boltzmann方法的体肺分流术血流动力学几何多维度数值研究

目的 利用基于时间步耦合的几何多维度方法,模拟单心室疾病体肺分流术后的血流动力学,得到搭桥管局部三维流场和手术前后整体血流动力学信息。方法 首先,通过术前的心血管集中参数模型（0D）和手术搭桥管三维模型（3D）建立0D-3D耦合的多维度血流动力学模型,并讨论模型0D-3D交界面耦合条件及时间步耦合算法;其次,实现了基于格子Boltzmann方法的3D 计算流体动力学（computational fluid dynamics, CFD）和0D集中参数模型耦合求解的多维度仿真;最后,通过多维度模型与术前集中参数模型的结果对比手术前后血流动力学变化。结果 多维度仿真得到了术后心血管整体血流动力学改变和手术局部的三维流场信息,模拟结果显示肺循环分流比由术前32.21%提高至57.8%。结论 体肺分流术中植入连接体循环和肺循环的搭桥管能够有效增加单心室病人肺循环的供血;几何多维度仿真能够有效模拟心血管整体血流动力学改变和所关心部位的三维流场信息,对心血管临床术前规划有重要意义。     

包含中国人群解剖学差异的Web端三维器官模型可视化系统的构建及应用

目的 数字三维解剖模型对于解剖学教育和临床医疗研究起到了积极的推动作用。现有的中国人数字三维模型多是基于一个标准的人类个体,不包含人与人之间的解剖形态变化差异,不利于使用者了解器官形态在不同人之间的变化。我们提出了1种基于万维网（Web）端的三维可视化人体躯干解剖形变模型,在浏览器网页中展示中国人群的器官解剖形态变化规律。 方法 通过统计形状模型技术,从138例健康中国人计算机断层扫描（CT）影像中学习到器官形态个体差异,并通过Web端浏览器交互展示这种变形差异。 结果 本系统实现了基于网络的操作模式,通过用户交互式操作调整模型参数来展示人体解剖学信息和个体间变化。结论 本研究中的Web端三维可视化解剖形变模型实现了跨平台、跨操作系统,达到了实时操作,为解剖教学与医疗应用提供了个体差异信息。     

Mimics辅助快速建立颅上颌复合体的三维有限元模型

背景：颅颌面部是骨骼系统中结构最复杂、功能最多样的的结构之一,要进行颅上颌骨复合体生物力学分析,就必须建立一个精准的三维有限元模型。 目的：探索快速建立完整颅上颌复合体三维有限元模型的方法。 方法：以牙列完整、咬合关系正常、磨牙为中性关系、牙周组织健康的成年志愿者作为建模素材,进行多层螺旋CT扫描,利用Mimics软件和MSC.Patran软件建立颅上颌复合体三维有限元模型。 结果与结论：探索出一条快速建立颅上颌复合体三维有限元模型的新方法。建立了三维坐标系下的可以从任意角度观察的健康人颅上颌复合体三维重建生物医学模型和三维有限元模型,由76 035个节点和373 819个单元组成。该模型具有较好的几何相似性和力学相似性。     

基于CT的兔肺肿瘤微波消融的温度场研究

目的探索基于三维重建肺肿瘤的微波消融仿真方法,为个性化手术规划模型提供理论基础。方法首先利用Mimics三维重建软件将荷瘤兔CT图像重建成三维数字化模型,同时在COMSOL仿真软件中构建了微波天线模型和理想化肺模型,组成微波消融仿真几何模型。然后采用有限元仿真方法,固定消融功率为30W,设置组织热物性参数及边界条件计算肿瘤组织和肺组织温度场分布,分析得出合适的消融参数。结果成功建立了13.63 mm×11.31 mm的椭球状肺肿瘤的三维模型。基于电磁场与温度场的计算,可以得到肿瘤温度场和肺组织温度场的分布。在使用消融功率30 W/消融时间300 s时,可以使其温度场完全覆盖兔肺肿瘤并预留出安全的消融边界。结论根据个性化肿瘤CT可成功建立其三维肿瘤模型,应用于仿真研究之中可以从肿瘤组织和肺组织温度场分布得到合适的消融参数,该法对降低微波消融肺肿瘤手术难度、改善微波消融肺肿瘤手术效果有着重要意义。     

基于生物力学信息数字化机器人辅助手术系统

目的 建立一套数字化机器人辅助手术系统再现真实手术过程,并通过仿真系统与外部力反馈设备的结合实现对虚拟环境中机器人的控制和力觉反馈。方法 系统的设计包括：基于生物力学理论的人体组织建模、基于有限元方法人体组织生物力学模型的计算、外部力反馈设备的设计、控制算法设计等。通过多层次模型、系统集成等方法,实现基于生物力学信息并具有交互特性的虚拟机器人辅助骨折牵引复位手术平台。结果 当主手控制系统和虚拟环境生成机通过局域网连接成功后,该系统完成了闭环信息传递过程。结论 该系统可以实现对虚拟环境中手术机器人的主从控制、视觉反馈和力觉反馈。该项研究为数字化模拟外科手术相关技术的发展起到推进作用,模拟手术在提高手术成功率、新医生的培训方面具有很强的优势。     

一个三维医学图像实时可视化系统4D View

通过结合国际上先进的可视化工具包 (VTK)和实时体绘制系统 (Volum e Pro) ,研制开发了医学图像实时可视化系统 4DView。该系统能够对 MR、CT等医学图像进行实时的三维可视化和交互操作。本文首先简单介绍了 VTK和 Volume Pro及其相互结合 ,然后详细讨论了 4DView的系统设计和各功能模块 ,最后给出了从 4DView系统获得的一些医学图像可视化结果。实验结果表明 ,4DView能有效地解决三维医学图像可视化及其交互操作实时性不强的问题 ,在临床诊断、治疗和医学研究等领域中具有极大的应用前景     

三维打印技术在骨组织工程领域的应用研究进展

综述了三维(3D)打印技术的出现、分类与优势等.介绍了该技术在骨组织工程领域的应用,包括光固化立体印刷、熔融沉积成型、选择性激光烧结和3D喷印的工作原理、存在的优缺点以及国内外学者在该领域的研究进展.目前骨组织工程支架的制备大多应用了3D打印技术,以生物可降解的活性材料为原料制备而成.在我国该领域虽然发展迅速,利用3D打印技术进行人工骨合成、骨科术前模拟等已经越来越普遍,亦取得了令人满意的效果,但要研发出合适的生物材料以及设备精度的改进仍是亟待解决的问题.目前,仿生器官的功能化已成为3D打印技术领域的一大困难,其中多细胞共培养、血管化及支架的制备是实现功能化必须克服的问题,相信通过努力,该项技术将会为器官的再生与修复带来更多令人瞩目的成果.     

On the utility of 3D hand cursors to explore medical volume datasets with a touchless interface

Analyzing medical volume datasets requires interactive visualization so that users can extract anatomo-physiological information in real-time. Conventional volume rendering systems rely on 2D input devices, such as mice and keyboards, which are known to hamper 3D analysis as users often struggle to obtain the desired orientation that is only achieved after several attempts. In this paper, we address which 3D analysis tools are better performed with 3D hand cursors operating on a touchless interface comparatively to a 2D input devices running on a conventional WIMP interface. The main goals of this paper are to explore the capabilities of (simple) hand gestures to facilitate sterile manipulation of 3D medical data on a touchless interface, without resorting on wearables, and to evaluate the surgical feasibility of the proposed interface next to senior surgeons (N = 5) and interns (N = 2). To this end, we developed a touchless interface controlled via hand gestures and body postures to rapidly rotate and position medical volume images in three-dimensions, where each hand acts as an interactive 3D cursor. User studies were conducted with laypeople, while informal evaluation sessions were carried with senior surgeons, radiologists and professional biomedical engineers. Results demonstrate its usability as the proposed touchless interface improves spatial awareness and a more fluent interaction with the 3D volume than with traditional 2D input devices, as it requires lesser number of attempts to achieve the desired orientation by avoiding the composition of several cumulative rotations, which is typically necessary in WIMP interfaces. However, tasks requiring precision such as clipping plane visualization and tagging are best performed with mouse-based systems due to noise, incorrect gestures detection and problems in skeleton tracking that need to be addressed before tests in real medical environments might be performed.     

A graphic tool for curating molecular interaction networks from the literature

We propose a graphic tool for curating molecular interaction networks constructed from the literature by information extraction (IE). In order to turn preliminary results from IE into useful biomedical resources, we propose to use a controlled environment in which visualization and IE work synergistically. The usability of the proposed graphic tool is shown with respect to the identification of incorrectly extracted results that are due to the much troubling coordination phenomena in natural language texts. Through the experiment on molecular interactions in Saccaharomyces cerevisiae, we have seen a meaningful increase (from 91.5% to 97.5%) in the number of correctly extracted interaction information.     

Imaging transforms for visualizing surfaces and volumes

Three-dimensional (3D) visualization in biomedical and other imaging areas is a rapidly emerging discipline. The major developments in this field are described in a unified and concise way. To this end, we introduce an operator notation to describe the basic imaging transforms commonly used in 3D visualization and to identify a comprehensive set of basic transforms. We also introduce several new basic transforms for filtering and interpolating scenes and structures and for rendering surfaces and volumes. We demonstrate not only how the existing visualization methodologies can be described concisely, but we also show how a great variety of new methodologies can be generated using both the existing imaging transforms and the new transforms introduced in this paper. A comprehensive evaluation method to compare objectively rendering methods used in visualization based on task-specific mathematical phantoms is described. We examine in detail separate transform sequences that are best suited for rendering robust and frail structures (ie, structures with well- and poorly defined boundaries).     

医学信息学的研究领域及人才培养

医学信息学(MedicalInformatics,又称医药信息学)是计算机科学、信息科学与医学科学结合,新近形成的前沿多学科交叉的科学,它以信息论、系统论、计算机科学技术为理论基础,几乎全方位地涉及所有的医药卫生领域,已成为现代和未来生物医学发展的基石。目前,医学信息学应用的领域,面临人才短缺的现象,本文论述了在生物医学工程学科中,建立医学信息本科专业方向,通过相关课程体系的设置,培养符合社会需要的医学信息人才。     

基于OK图像采集卡和VTK的医学图像处理系统

目的针对当前医学图像处理的需要,在VTK类库提供的可视化与显示功能的基础上,用VC＋＋2008设计和实现一个可集成于OK图像采集卡的三维可视化系统。方法在VC＋＋2008平台下,结合可视化工具包VTK,对DICOM格式的CT图像序列进行面绘制和体绘制,通过设置虚拟切面的内点和法向量对重建后的三维物体进行切割并获得虚拟切片的信息,在切割的同时可以同步显示出虚拟切片图像。结果实验结果表明,该系统能有效地实现DICOM医学图像的体绘制和表面绘制,并且可以在任意方向切割、旋转、放大与平移三维图像。结论上述系统对增强OK图像采集卡的后处理功能具有重要作用,在理论研究和临床应用上有重要意义和研究价值。     

ApiNATOMY: a novel toolkit for visualizing multiscale anatomy schematics with phenotype-related information

A significant proportion of biomedical resources carries information that cross references to anatomical structures across multiple scales. To improve the visualization of such resources in their anatomical context, we developed an automated methodology that produces anatomy schematics in a consistent manner,and provides for the overlay of anatomy-related resource information onto the same diagram. This methodology, called ApiNATOMY, draws upon the topology of ontology graphs to automatically lay out treemaps representing body parts as well as semantic metadata linking to such ontologies. More generally, ApiNATOMY treemaps provide an efficient and manageable way to visualize large biomedical ontologies in a meaningful and consistent manner. In the anatomy domain, such treemaps will allow epidemiologists, clinicians, and biomedical scientists to review, and interact with, anatomically aggregated heterogeneous data and model resources. Such an approach supports the visual identification of functional relations between anatomically colocalized resources that may not be immediately amenable to automation by ontology-based inferencing. We also describe the application of ApiNATOMY schematics to integrate, and add value to, human phenotype-related information—results are found at http://apinatomy.org. The long-term goal for the ApiNATOMY toolkit is to support clinical and scientific graphical user interfaces and dashboards for biomedical resource management and data analytics.     

Interactive Visualization and Analysis of Multimodal Datasets for Surgical Applications

Surgeons use information from multiple sources when making surgical decisions. These include volumetric datasets (such as CT, PET, MRI, and their variants), 2D datasets (such as endoscopic videos), and vector-valued datasets (such as computer simulations). Presenting all the information to the user in an effective manner is a challenging problem. In this paper, we present a visualization approach that displays the information from various sources in a single coherent view. The system allows the user to explore and manipulate volumetric datasets, display analysis of dataset values in local regions, combine 2D and 3D imaging modalities and display results of vector-based computer simulations. Several interaction methods are discussed: in addition to traditional interfaces including mouse and trackers, gesture-based natural interaction methods are shown to control these visualizations with real-time performance. An example of a medical application (medialization laryngoplasty) is presented to demonstrate how the combination of different modalities can be used in a surgical setting with our approach.