基于三维扫描重构技术的导弹外形误差测量系统

基于三维扫描重构技术,根据导弹外形特征采用三维扫描全局统一测量技术建立非接触式的导弹外形误差测量系统,实现复杂弹体外形快速准确的测量。并通过系统接口使用CAD软件完成结构特性计算及分析,具有传统测量方法无法比拟的优势和先进性。

A New Method for 3D Finite Element Modeling of Human Mandible Based on CT Data

This study presents a reliable method for the semi-automatic generation of an FE model, which determines both geometrical data and bone properties from patient CT scans.3D FE analysis is one of the best approaches to predict the stress and strain distribution in complex bone structures, but its accuracy strongly depends on the precision of input information. In geometric reconstruction, various methods of image processing, geometric modeling and finite element analysis are combined and extended. Emphasis is given to the assignment of the material properties based on the density values computed from CT data. Through this technique, the model with high geometric and material similarities were generated in an easy way. Consequently, the patient-specific FE model from mandible CT data is realized also.

全髋关节成形术后的偏心距测量对临床功能的影响

[目的]探讨全髋关节置换术后股骨偏心距的测量研究对临床功能的影响。[方法]选取2009年9月～2011年9月本院收治的61例单侧关节病患者,对其行髋关节置换术后测量股骨偏心距,采用三维CT扫描重建技术及X线影像技术分别为61例患者测量。通过手术前后股骨偏心距的变化及Harris评分系统评价术前和术后临床功能的变化。[结果]术后股骨偏心距较术前显著增加(P<0.001);观察组的标准明显高于对照组(P<0.001);术后比术前Harris分明显提高。[结论]相对于X线影像技术,3D CT扫描重构技术的术前规划可较容易地获得测量值,且由于框架建立在股骨轴上,其获得不依赖测试时的条件,并不受位置变化的影响。