基于最大互信息的医学图像配准算法

本文提出一种新的基于轮廓提取和最大互信息理论的医学图像配准的算法。该算法克服了在配准过程中存在鲁棒性因素、出现误配情况及互信息单一的利用图像灰度信息的局限性,将边缘检测与互信息相结合,提高了原有算法的性能,可较准确地完成图像配准任务。本文并对提出的配准算法进行了Matlab仿真实验,对仿真结果进行分析。     

基于双重边缘检测和区域生长的大脑皮层分割算法

目的设计一种数字人脑切片图像自动分割算法,以实现对大脑皮层的准确分割。方法采用RGB空间彩色边缘检测与Canny算子边缘检测,联合种子点自动选择的区域生长算法,提取并分割大脑皮层,并与手工分割结果进行对比分析。结果自动分割的大脑皮层边缘完整、清晰、平滑,与手工分割结果的吻合度较高。结论采用该方法可较为准确地分割数字人脑切片图像中的大脑皮层。     

交互式医学图像控制系统在正颌外科手术中的应用

目的 探讨交互式医学图像控制系统（MIMICS）在计算机辅助手术中的应用价值,为术前进行精确设计手术方案及达到术后良好效果提供真实可靠依据。方法 对2例正颌外科手术患者的头面部三维CT断层扫描图像,进行识别确定重建对象,对皮肤、皮下组织及骨组织采用灰度阈值法进行自动重建;采用MIMICS软件对获取的医学信息进行分层网格划分,完成建模。根据资深正颁外科医师制订的方案,在模型中完成手术的模拟和软组织形变的预测。结果 完成了包含皮肤、皮下组织和骨组织的患者头面部三维网格模型。模拟了正颌外科手术移动骨质过程,并且以动态动画形式演示,可从任意角度进行观察。实现了正颌外科手术术后软组织形变的可视化预测。结论 利用医学影像资料,采用MIMICS软件可实现人头面部复杂结构的三维重建和分层网格划分,以动态形式完成正颌外科手术的模拟和软组织形变预测。在计算机屏幕前制订手术方案进行医患交流,共同协商,提高了正颌外科手术安全性、精确性和矫治效果。     

经食管超声心动图自动边缘检测的临床应用

１１例风湿性心瓣膜患者在体外循环下替换了人工机械二尖瓣和主动脉瓣，术后１小时施行ＰＥＥＰ０～１．０ｋＰａ的机械呼吸。应用经食管心动超声，自动边缘检测技术，在ＰＥＥＰ０、０．４、０．６和１．０ｋＰａ四个阶段同步地记录并计算了左、右房室的四个腔的舒张未面积、收缩末面积，每搏面积、最大面积变化率、最小面积变化率、峰值充盈率、峰值排空率。心动超声指标显示：增高呼气末压时右心的影响比左心大，既使呼气未压高达１．０ｋＰａ，ＣＶＰ虽升高，血流动力学尚能保持稳定，右心的每搏面积减少而左心每搏面积并无显著改变，尤其是ＰＥＥＰ０．６ｋＰａ时，虽右房室的每搏面积减少２０％和２１％，但此时房室的每搏面积无明显改变。面对肺内压的增加，右心尚有能力加快其充盈和排空，左房室的充盈和排空加快２０％的趋势有利于肺水的消除。故认为ＰＥＥＰ０．６ｋＰａ不失为此时机械呼吸的佳值。     

医学图像三维可视化系统在肝胆管结石病诊断与治疗中的应用

目的 研究医学图像三维可视化系统(MI-3DVS)在肝胆管结石病诊断与治疗中的应用价值.方法 收集2008年8月至2010年8月南方医科大学珠江医院收治的54例肝胆管结石病患者的肝脏64排螺旋CT扫描原始数据,采用MI-3DVS进行肝脏及胆道三维重建.根据三维重建结果进行术前诊断和病理分型,以及多种手术方案的术前仿真演练,确定最佳手术方案.观察术中所见与仿真手术的符合程度以及患者结石残留情况.结果 54例患者中,病理分型Ⅰ型11例,Ⅱ型5例(其中Ⅱa型2例、Ⅱb型3例),E型38例;肝内胆管狭窄23例;伴萎缩-肥大综合征27例.肝内外胆管的立体解剖形态,病变胆管扩张及狭窄部位和程度,肝内胆管结石的部位、大小及数量可精确显示.仿真手术方案与实际手术的符合率为94%(51/54),51例择期手术患者术后无结石残留,全组术后结石残留率为6%(3/54).结论 MI-3DVS可实现肝胆管结石病的术前精确诊断和术中精细操作,可有效降低术后结石残留率.     

三维医学图像重建及计算机手术导航在脊柱外科的应用

近几年，伴随计算机图形技术的迅猛发展及超级图像工作站、医学影像设备的不断升级，将空间三维定位系统、计算机医学图像处理及三维可视化技术应用于临床，建立定量诊断、手术模拟与预测、立体定向导航和远程医疗等计算机辅助外科手术系统的研究，已成为生物医学工程研究的热门领域，其应用前景引人瞩目。     

腹部医学图像三维可视化系统用于腹主动脉瘤诊治临床研究

目的 研究腹部医学图像三维可视化系统在腹主动脉瘤诊断及治疗中的应用价值。方法 2008年1月至2010年1月南方医科大学珠江医院收集13例腹主动脉瘤病人64排螺旋CTA数据,利用DICOM Viewer进行重建前处理,导入自主开发的腹部医学图像三维可视化系统进行图像分割及三维重建,然后对13例病人腹主动脉瘤重建模型进行数字化分型、分级,测量各项参数,选择合适的手术方式,最后将重建模型导入FreeForm Modeling System仿真手术平台进行腹主动脉瘤仿真人工血管置换及腔内隔绝手术研究,评估腹部医学图像三维可视化系统的应用价值。结果 13例病人腹腔三维模型形态逼真,立体感强,相互关系明晰;腹主动脉瘤分型、分级准确;仿真手术符合临床开放及腔内手术过程。结论 腹部医学图像三维可视化系统有利于腹主动脉瘤术前的评估及手术方式的选择;可视化仿真开放及腔内手术可让术者熟悉手术过程,缩短手术时间,提高手术者的操作技能;加强医患沟通。     

腹部医学图像三维可视化系统辅助肝胆管结石诊治决策的价值

目的 研究腹部医学图像三维可视化系统在辅助肝胆管结石诊治决策中的价值。方法 选取南方医科大学珠江医院2007-2009年收治的22例肝胆管结石病人的肝脏64排CT扫描数据,将数据导入腹部医学图像三维可视化系统进行程序分割、三维重建。根据三维模型制定诊治策略,利用自主研发的虚拟手术器械仿真系统进行仿真手术并指导临床手术。结果 22例病人中,I型4例,Ⅱ型2例,E型16例。多次胆道手术6例;局部胆管狭窄16例;伴肝硬化5例;伴萎缩-肥大综合征16例。三维模型清晰显示结石的大小、数量、形态、空间位置;胆管狭窄的位置、程度、长度。对照此后进行的手术,重建模型与术中所见均符合,手术方式符合者19例（不符合3例均为急诊入院）;非急诊手术病人术后行直接胆道造影显示无结石残留。结论 腹部医学图像三维可视化系统能更快速准确地诊断肝胆管结石,有助于治疗策略的选择,指导个体化手术方式。     

一种检测气管导管位置的新方法

气管插管操作不当会造成气管导管误入食管,误入一侧支气管或滑出气管,发现不及时会产生严重后果。目前临床上一般采用听诊,支气管镜检查,呼气末CO2检测,变色试纸等方法来判断。本文利用Hall传感器可以检测微     

非贵金属烤瓷冠两种冠边缘的临床应用

目的:探讨非贵金属PFM冠边缘不同类型修复的临床意义。方法:为了克服非贵金属PFM本身的不足,对上前牙非贵金属PFM唇侧采用肩台瓷修复;对后牙采用羽状边缘3600金属颈环修复。结果:34颗前牙非贵金属PFM肩台瓷修复及138颗后牙非贵金属PFM羽状边缘3600金属颈环修复,效果满意。结论:前牙肩台瓷及后牙羽状边缘3600金属颈环烤瓷冠是针对非贵金属PFM冠边缘不足的一种实用方法。     

A discretization method for the numerical solution of Dieudonné–Rashevsky type problems with application to edge detection within noisy image data

The present paper is concerned with the numerical solution of multidimensional control problems of Dieudonné–Rashevsky type by discretization methods and large‐scale optimization techniques. We prove first a convergence theorem wherein the difference of the minimal value and the objective values along a minimizing sequence is estimated by the mesh size of the underlying triangulations. Then we apply the proposed method to the problem of edge detection within raw image data. Instead of using an Ambrosio–Tortorelli type energy functional, we reformulate the problem as a multidimensional control problem. The edge detector can be built immediately from the control variables. The quality of our numerical results competes well with those obtained by applying variational techniques. Copyright © 2011 John Wiley & Sons, Ltd.     

Optimal locations for MR dampers in civil structures using improved Ant Colony algorithm

This paper studies a design problem concerning installation locations for a number of structural magneto‐rheological (MR) dampers. The mechanical characteristic of each MR damper is functional dependent to an input current, which is regulated by a Fuzzy Logic controller. It is demanded that the chosen arrangement of dampers should change the dynamic response of the structure to meet certain constraints expressed in terms of minimization of an objective function. For this purpose, an improved version of Ant Colony Optimization algorithm is presented. The modified algorithm also utilizes additional heuristic data derivable from a pre‐analysis of the structure in the optimization procedure. Further improvements regarding convergence speed of search algorithm are proposed as well, provided numerical examples study the functionality of the algorithm in different cases. With an acceptable probability from a structural designer's point of view, the proposed method finds qualified solutions during a reasonable number of search iterations. Copyright © 2011 John Wiley & Sons, Ltd.     

图像分割技术在血管图像中的应用

图像分割是一种重要的图像技术,是进一步图像分析和处理的基础。血管系统成像在临床医疗过程中发挥着重要的作用。临床医生了解一些常用的医学图像分割方法,有利于其在临床工作中根据图像特征和分割要求来选择适合的方法,提高图像质量,做出正确的诊断。本文综述图像分割技术在血管图像方面的应用。     

An Internet-based tool for evaluating third-year medical student performance

BACKGROUND: Shortened non-primary care medical school clerkships have increased time pressures for accurate assessment of student knowledge, skills, and attitudes. Paper-based student evaluations suffer from low response rates, inefficient data acquisition and analysis, and difficulty obtaining input from multiple evaluators. This project describes the development of a Web-based model for evaluating third-year medical student performance, improving evaluation response rates, and including multiple evaluators' input. METHODS: A secure Web-based system was designed to maintain evaluation data (11-item competency-based evaluations, oral examinations, National Board of Medical Examiners surgery test, and objective structured clinical examination) for the third-year surgery clerkship. Historical response rate, completion time, and administrative effort data were compared with data obtained using the Web-based model. RESULTS: Faculty response rates improved from 71.3% to 89.9%, with response times decreased from 28.0 +/- 3.0 to 9.0 +/- 0.7 days using the Web-based model. Administrative time requirements decreased from 5 days to 2 hours per rotation, and manual data entry, analysis, and reporting were eliminated through e-mail evaluator notification, direct data entry, and real-time analysis. Evaluator satisfaction was subjectively higher using the Web-based model. CONCLUSIONS: The Web-based 360-degree evaluation model improves third-year medical student assessment by including residents, reducing time and cost, and by providing a faster, more inclusive, and efficient evaluation.     

An improved technique for coronary vascular anastomosis.

A vein holder is described that is used for anastomosis of both ends of aortocoronary bypass grafts. It minimizes handling of the graft, ensures precision in placing sutures with excellent visualization, and provides maximum patency at the anastomotic sites.     

An improved method for repair of pectus chest deformities

An improved method for repair of pectus excavatum is presented. The method may also be used for repair of asymmetrical funnel chest and pectus carinatum.The principles of repair are to (1) remove the deformed costal cartilages, (2) eliminate the flare of the lower ribs, (3) place the sternum in its normal anatomical position, and (4) reestablish costosternal union.Deformed cartilages are excised subperichondrially. Removal of the costal margin is carried to the apex of the defect. The margin is then made continuous by approximating the free ends in the midline. This latter maneuver eliminates the costal flare. The remaining ribs are brought into apposition with the sternum. The sternum is immediately stable in the normal anatomical position. No extrinsic devices are used.     

Pre-simulation orientation for medical trainees: An approach to decrease anxiety and improve confidence and performance

Background

We assessed the effect of basic orientation to the simulation environment on anxiety, confidence, and clinical decision making.