医用光学成像方法研究综述     

王锦  赵友全 《天津工程师范学院学报》2005,15(3):34-37

从医学成像的角度,以实践为基础,总结并给出了一些直接或间接的医学光成像实际方法,讨论了不同方法的优缺点及其关联性,指出了医学中光成像的发展方向.  相似文献   

提高光学接收效率的一种方法     

晁明举  三洋  孙体楠 《商丘师范学院学报》1997,(Z2)

针对半导体激光器所发激光束偏振性差、发散角大的特点，提出了一种用中间拖孔的平面镜代替通常所用分束片的方法，来达到分离光束的目的，并且与分束片相比，光学效率可得到明显提高．  相似文献   

Comparison study of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography     

赵博文  汤富刚  寿金朵  徐海珊  吕江红  范妙英  范晓明  潘美 《浙江大学学报(A卷英文版)》2003,4(3):374-377

Objectives: To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities. Methods: Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI. Results: Mean HI scores were higher than mean FI scores (2.73±0.43 vs 2.16±0.69, P<0.001)for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73±0.43 vs 2.88±0.32, P<0.001) and suboptimal (1.65±0.41 vs 2.58±0.47, P<0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 (P<0.001). Conclusions: harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus.  相似文献   

成像系统对图像的退化作用     

武英 《南京晓庄学院学报》2004,20(4):19-22

文中讨论了成像系统对静止图像质量产生的影响,综合考虑系统的各个组成部件的传递函 数,建立成像系统对图像退化的模型(传递函数),通过计算机模拟生成了退化后的图像。  相似文献   

The effect of low back pain on trunk muscle size/function and hip strength in elite football (soccer) players     

Julie A. Hides  Tim Oostenbroek  Melinda M. Franettovich Smith  M. Dilani Mendis 《Journal of sports sciences》2016,34(24):2303-2311

ABSTRACT

Low back pain (LBP) is a common problem in football (soccer) players. The effect of LBP on the trunk and hip muscles in this group is unknown. The relationship between LBP and trunk muscle size and function in football players across the preseason was examined. A secondary aim was to assess hip muscle strength. Twenty-five elite soccer players participated in the study, with assessments conducted on 23 players at both the start and end of the preseason. LBP was assessed with questionnaires and ultrasound imaging was used to assess size and function of trunk muscles at the start and end of preseason. Dynamometry was used to assess hip muscle strength at the start of the preseason. At the start of the preseason, 28% of players reported the presence of LBP and this was associated with reduced size of the multifidus, increased contraction of the transversus abdominis and multifidus muscles. LBP decreased across the preseason, and size of the multifidus muscle improved over the preseason. Ability to contract the abdominal and multifidus muscles did not alter across the preseason. Asymmetry in hip adductor and abductor muscle strength was found between players with and without LBP. Identifying modifiable factors in players with LBP may allow development of more targeted preseason rehabilitation programmes.  相似文献   

基于GIS和高分辨SAR数据的机场净空建筑物高度提取     

杨盛华  邢绍伟  张农  尹洋  张月  郭欣萌 《北京工业职业技术学院学报》2019,18(2):117-121

随着SAR图像分辨率的进一步提高,建筑物在SAR图像中的特征更加明显,使得基于单幅高分辨率SAR图像进行建筑物提取和三维重构成为可能。分析高分辨率SAR图像中建筑物的成像散射特征,多次反射及阴影效应;阐述基于GIS空间数据进行SAR图像中建筑物定位和估算建筑物的高度的算法。利用高分辨率TerraSAR-X数据,估算天津机场净空区某小区建筑物高度,与实际高度数据相比较,发现计算结果精度较高。结果表明:该方法是一种可行的建筑物高度提取方法,可为需要大面积建筑物高度的相关应用提供很好的借鉴方法。  相似文献   

Study of clinical features of amyloid angiopathy hemorrhage and hypertensive intracerebral hemorrhage   总被引：3，自引：0，他引：3  

詹仁雅  童鹰  沈剑峰  LANG E.  PREUL C.  HEMPELMANN R.G.  HUGO H.H.  BUHL R.  BARTH H.  KLINGE H.  MEHDORN H.M 《Journal of Zhejiang University. Science. B》2004,(10)

Objective: The purpose of this study was to differentiate between cerebral amyloid angiopathy (CAA) and hypertension (HTN) based on hemorrhage pattern interpretation. Methods: From June 1994 to Oct., 2000, 83 patients admitted to our service with acute intracerebral hemorrhage (ICH) were investigated retrospectively; 41 patients with his-tologically proven diagnosis of cerebral amyloid angiography and 42 patients with clear history of hypertension were investigated. Results: Patients with a CAA-related ICH were significantly older than patients with a HTN-related ICH (74.0 years vs 66.5 years, P<0.05). There was a significantly higher number of hematomas>30 ml in CAA (85.3%) when compared with HTN (59.5%). No basal ganglional hemorrhage was seen in CAA, but in 40.5% in HTN. In CAA-related ICH, su-barachnoid hemorrhage (SAH) was seen in 26 patients (63.4%) compared to only 11 patients (26.2%) in HTN-related ICH. Intraventricular hemorrhage was seen in 24.4% in CAA, and in 26.2% in HTN. Typical features o  相似文献   

影像启发式教学与思维导图在医学新生研讨课程实践中的联合应用     

陶莎莎 《教育教学论坛》2019,(27):139-140

以新生研讨课“土壤污染与人类健康”为例,将视频观看模式关联的启发式教学与思维导图模式的思考方式相结合融入教学过程,以探讨新的教学模式。从课程背景、教学过程、教学反思三个层面阐述,实践表明该教学模式可提高学生自主学习能力,轻松掌握知识以及养成良好的思维习惯。最后文章还提出了该教学模式应注意的几个问题。  相似文献   

基于小世界网络分析的小球类专项学生运动员脑网络可塑性变化研究     

杨成波  向宇  黄月  陈华富  高晴 《中国体育科技》2020,(6):56-61

目的:基于小世界分析方法,探测小球类专项学生运动员大脑的结构网络及功能网络的可塑性变化。方法:收集小球类专项学生运动员和与之匹配的普通被试作为对照组,采集静息态,3DT1及DTI磁共振数据。首先根据DTI纤维追踪结果构建结构网络,根据功能连接构建功能网络。进一步计算不同稀疏度下的结构及功能网络的网络属性。结果:通过计算其网络属性发现,小球类专项学生运动员与普通被试的结构及功能网络都具有小世界特性。小球类专项学生运动员组的结构网络及功能网络的聚类系数和局部效率比对照组高,在部分稀疏度下存在明显差异。其中,结构和功能网络的全局聚类系数显著相关。结论:小球类专项学生运动员大脑的结构网络及功能网络的聚类系数和局部效率比普通被试高,且结构和功能网络的全局聚类系数显著协变,说明小球类专项学生运动员的脑连接比普通被试多,脑区之间通信更加迅速有效,信息容错能力更强,且小球类专项学生运动员的脑结构、功能网络具有一致的可塑性变化。  相似文献   

一个用于体外评价超声造影剂显影效果的系统（英文）     

陈平  杨芳  房坤  顾爱远  钱卓宇  王鹏  顾宁 《东南大学学报》2010,26(1):82-86

构建并评价了一个用于体外研究超声造影剂显影效果的系统,该系统包括一套数字化B型超声诊断仪Belson3000A、仿组织超声体模和用于图像量化分析的软件.制备了具有不同反射强度的仿组织超声体模,通过对这些体模材料超声成像,研究了B超系统的线性范围、参数设置和系统的重复性等.超声成像设置为：输出声功率为4.8 ～12.3mW,探头的中心频率为3.5MHz,总增益为50dB.利用该系统,对自制备的表面活性剂微气泡和一种商用造影剂进行了显影成像.结果表明超声图像的灰度值随声功率的增加而增大,强反射特性的超声体模成像时,这种增加趋势更明显.该系统适合用于体外评价超声造影剂的显影效果,为体外表征超声微气泡造影剂的显影能力提供了一种简单、有效、实时的评价方法.  相似文献