基于平滑伪魏格纳分布的人体结肠压力信号分析

目的：对人体结肠压力信号进行时频分析，探求人体结肠的运动学和动力学特性。方法：采用瑞典CTD-SYNETICS公司生产的胃肠道功能监测仪测试结肠功能正常和异常受试者的结肠压力数据，并采用平滑伪魏格纳分布分析人体结肠压力信号。结果：从人体结肠压力信号的平滑伪魏格纳分布，可以看出三类结肠动力特性：正常动力．动力过缓和动力紊乱，与临床观察相符。结论：平滑伪魏格纳分布具有良好的时频分辨率，可以在降低噪声干扰的同时有效地分析出信号的规律性。采用平滑伪魏格纳分布能够有效分析结肠压力信号的特性，为揭示结肠动力特性提供有用的手段。     

基于平滑伪魏格纳分布的人体结肠压力信号分析

目的:对人体结肠压力信号进行时频分析,探求人体结肠的运动学和动力学特性。方法:采用瑞典CTD-SYNETICS公司生产的胃肠道功能监测仪测试结肠功能正常和异常受试者的结肠压力数据,并采用平滑伪魏格纳分布分析人体结肠压力信号。结果:从人体结肠压力信号的平滑伪魏格纳分布,可以看出三类结肠动力特性:正常动力、动力过缓和动力紊乱,与临床观察相符。结论:平滑伪魏格纳分布具有良好的时频分辨率,可以在降低噪声干扰的同时有效地分析出信号的规律性。采用平滑伪魏格纳分布能够有效分析结肠压力信号的特性,为揭示结肠动力特性提供有用的手段。     

结肠压力测量方法介绍

消化道测压是广泛使用的评价消化道功能的检查手段,对消化道运动障碍疾病的诊断有较高的价值,是其他检查手段不可替代的。文章从结肠压力信号中提取有效的特征,采用学习矢量量化的方法进行结肠压力信号的识别。学习结果表明,这种方法可以将结肠压力信号分为正常与异常两组,与初始的医疗诊断相符合。这一研究为进一步根据结肠压力信号识别肠道各段的动力性能奠定了基础。     

压力性损伤护理虚拟仿真实训项目的构建及应用效果

目的 构建压力性损伤护理的虚拟仿真实训项目并探索其应用效果.方法 利用计算机网络和虚拟仿真技术的优势,构建压力性损伤护理的虚拟仿真实训项目,包括理论学习、技能训练、综合应用三大模块,并在我校2018级58名本科生基础护理学课程教学中初步应用.课后用自行设计的调查表了解学生对项目学习的评价,同时应用平台获取的数据了解学习者应用本项目的情况并分析学生的学习成绩.结果 94.8%的学生对本项目有较大的学习兴趣,所有的学生认为本项目对掌握压力性损伤知识有较大帮助,96.6%学生愿意到该网站上再次学习相关内容.数据分析显示,学生对压力性损伤各模块知识点答题的正确率呈明显上升趋势,首次平均正确率为68.2%,第2次为92.6%,第3次达到100%.目前已有来自全国19个省、市、自治区的学习者访问本项目网站,数量高达6 410人次.结论 虚拟仿真实训项目可有效提升学生的学习兴趣与学习效果,帮助学生更好地掌握压力性损伤的相关知识与技能.本项目为优质实验教学资源共享提供了一个有效的实训平台.     

直肠癌结肠造口病人压力的研究进展

探讨直肠癌结肠造口病人的压力源、压力及压力应对方式等,旨在为今后有效减少直肠癌结肠造口病人的压力源、缓解压力提供新的思路.     

利用交互式数据语言处理医学数字图像的初步研究

目的：交互式数据语言IDL不仅提供了与C／C＋＋和FORTRAN等语言同样的编程能力，而且具备交互性、图形显示和面向矩阵的运算等性能。故探讨基于IDL的医学数字图像处理技术，以期推动其在国内医学影像学科的应用。 方法：在PC机上应用IDL6．1编程，程序在Windows XP平台上运行。①读取和显示DICOM格式的医学图像。①对MRI，CT和数字乳腺钼靶图像进行图像平滑、边缘增强、直方图均衡和局部放大镜功能等处理。③与非交互式程序设计语言在编程效率方面进行比较，以表现IDL面向矩阵、集成多种图像和图形命令以及编程简易的优点。 结果；利用IDL的交互特性，使用若干条命令以及调用IDL内建的图像处理程序包或函数，便可轻松地完成一般的医学图像处理工作，而这是C／C＋＋或FORTRAN语言所难以做到的。 结论：IDL是每个会使用计算机的人都能容易理解的一种计算机语言，具有对海量数据进行获取、分析、可视化以及对多种图像进行处理和交互式操作的功能，非常适合用来进行二维或三维医学数字图像处理。IDL在医学影像学领域的推广应用，必将促进医学图像处理与分析水平的进一步提高。     

直肠癌结肠造口患者压力源与应对方式的研究

目的 了解结肠造口患者的压力源及应对方式,制定有效的护理干预措施,提高患者生活质量,为临床护理提供依据.方法 采用便利抽样法对91例结肠造口患者进行问卷调查,并进行分析.结果 最常见的压力源为造口对日常生活的影响、造口护理情况、治疗方法 与效果,最常见应对方式为面对,其次为回避与屈服.结论 护理人员应协助结肠造口患者采取积极有效的应对方式,缓解其心理压力程度,提高生活质量.     

螺旋CT三维容积重建的临床应用

目的：探讨螺旋ＣＴ三维容积重建（ＶＲ）成像方法,评价其临床运用范围与价值。材料及方法：ＶＲ三维重建４７例,包括：①血管组１９例,②骨关节组１６例,③其它部位组１２例。扫描技术及造影剂使用参数据部位及病变性质具体设置,同时比较ＶＲ与表面遮盖法（ＳＳＤ）及最大强度投影（ＭＩＰ）。结果：选择２或３个目标、合适的衰减值及不透明度的限值可获得良好的ＶＲ立体成像。ＶＲ能显示血管管腔、血管之间、血管与周围器官的     

基于分形特征序列的乳腺X线图像分类方法

目的表征乳腺图像中肿块部分纹理特征,通过纹理分析实现乳腺图像中肿块部分与正常腺体部分的分类。方法应用分形特征值表征乳腺图像纹理特征,利用多级分形特征提取法将乳腺图像分解成一系列细节图像,提取出多个分形特征值;利用分类精度、ROC曲线及曲线下面积(AUC)进行特征选择构建分形特征序列,最后应用支持向量机(SVM)方法进行分类。结果对60幅图像的可疑病变区域进行分形特征序列提取分析,SVM交叉验证分类精度达84.50%。结论基于分形维数的乳腺图像分类方法不仅能对肿块与正常腺体进行图像分类,还可有效表征乳腺图像的纹理信息,有助于提高乳腺肿块诊断的准确率。     

利用交互式数据语言处理医学数字图像的初步研究

目的:交互式数据语言IDL不仅提供了与C/C 和FORTRAN等语言同样的编程能力,而且具备交互性、图形显示和面向矩阵的运算等性能。故探讨基于IDL的医学数字图像处理技术,以期推动其在国内医学影像学科的应用。方法:在PC机上应用IDL6.1编程,程序在WindowsXP平台上运行。①读取和显示DICOM格式的医学图像。②对MRI,CT和数字乳腺钼靶图像进行图像平滑、边缘增强、直方图均衡和局部放大镜功能等处理。③与非交互式程序设计语言在编程效率方面进行比较,以表现IDL面向矩阵、集成多种图像和图形命令以及编程简易的优点。结果:利用IDL的交互特性,使用若干条命令以及调用IDL内建的图像处理程序包或函数,便可轻松地完成一般的医学图像处理工作,而这是C/C 或FORTRAN语言所难以做到的。结论:IDL是每个会使用计算机的人都能容易理解的一种计算机语言,具有对海量数据进行获取、分析、可视化以及对多种图像进行处理和交互式操作的功能,非常适合用来进行二维或三维医学数字图像处理。IDL在医学影像学领域的推广应用,必将促进医学图像处理与分析水平的进一步提高。     

Fractal dimension and white matter changes in multiple sclerosis

The brain white matter (WM) in multiple sclerosis (MS) suffers visible and non-visible (normal-appearing WM (NAWM)) changes in conventional magnetic resonance (MR) images. The fractal dimension (FD) is a quantitative parameter that characterizes the morphometric variability of a complex object. Our aim was to assess the usefulness of FD analysis in the measurement of WM abnormalities in conventional MR images in patients with MS, particularly to detect NAWM changes. First, we took on a voxel-based morphometry approach optimized for MS to obtain the segmented brain. Then, the FD of the whole grey-white matter interface (WM border) and skeletonized WM was calculated in patients with MS and healthy controls. To assess the FD of the NAWM, we focused our analysis on single sections without lesions at the centrum semiovale level. We found that patients with MS had a significant decrease in the FD of the entire brain WM compared with healthy controls. Such a decrease of the FD was detected not only on MR image sections with MS lesions but also on single sections with NAWM. Taken together, the results showed that FD identifies changes in the brain of patients with MS, including in NAWM, even at an early phase of the disease. Thus, FD might become a useful marker of diffuse damage of the central nervous system in MS.     

应用分形维数定量分析MSCT肺动脉树形态学改变

目的 应用分形维数(FD)定量分析多层螺旋CT肺动脉树的形态学改变。方法 对31例患者进行增强螺旋CT扫描和经胸超声心动图检查,根据病变分为肺动脉高压组(PH组,14例)和无肺动脉高压组(无PH组,17例)。应用后处理软件形成肺动脉树,以Image J软件计算肺动脉树的投影面积及分形维数(FD);比较两组FD、肺动脉树投影面积和肺动脉压力(PAP),分析三者的相互关系。结果 PH组FD、图像投影面积和PAP均显著高于无PH组。肺动脉树的FD值与PAP、FD与图像投影面积,PAP与图像投影面积均存在正相关(r=0.82,P<0.05;r=0.49,P<0.05;r=0.65,P<0.05)。结论 FD能定量评价整个肺动脉的形态学改变,或可作为定量描述整个肺动脉形态学的重要指标之一。     

Fractal dimension estimation of carotid atherosclerotic plaques from B-mode ultrasound: a pilot study

In this paper, a pilot study regarding carotid atherosclerotic plaque instability using B-mode ultrasound (US) images was carried out. The fractal dimension of plaques obtained from ten symptomatic subjects (i.e., subjects having experienced neurological symptoms) as well as from nine asymptomatic subjects, was estimated using a novel method, called the kth nearest neighbour (KNN) method. The results indicated a significant difference, as per the fractal dimension, between the two groups, providing a significantly lower value for the asymptomatic group. Moreover, the phase of the cardiac cycle (systole/diastole) during which the fractal dimension was estimated had no systematic effect on the calculations. The fractal dimension of the plaques was also estimated using a well-known method, namely the box-counting (BC) method. No significant differences between the two groups, as per the fractal dimension, were observed using the BC method. The presented pilot study suggests that the fractal dimension, estimated by the proposed method, could be used as a single determinant for the discrimination of symptomatic and asymptomatic subjects.     

Rational function approximation for feature reduction in hyperspectral data

In this letter, we propose a feature extracting technique by using rational function curve fitting. A unique rational function curve is developed to fit the spectral signature of each pixel in a hyperspectral image. Polynomial coefficients in the numerator and denominator of the fitted curve are considered as new extracted features. The main contribution of this letter is utilization of curve-fitting ability in order to classify and compress hyperspectral data. In other words, naturally different curves can be discriminated when they are approximated by rational functions with equal form, but different amounts of coefficients. This rational function curve fitting feature extraction method provides better classification results compared to some common feature extraction algorithms when a maximum likelihood classifier is used. The method also has the ability of lossy data compression since the original data can be reconstructed using the fitted curves. In addition, the proposed algorithm has the possibility to be applied to all pixels of image individually, independently and simultaneously, unlike methods like principal component analysis which need to know all data points to compute the transformation matrix before transforming data points to new feature space.     

Hybrid genetic algorithm for feature selection with hyperspectral data

This letter evaluates the performance of a wrapper–filter genetic algorithm (GA) for feature selection using Digital Airborne Imaging Spectrometer hyperspectral data set. Classification accuracy by k-nearest neighbour (k-NN) and support vector machine (SVM) were used as fitness function with four filter algorithms. Results of wrapper–filter GA-based feature selection approach were compared with a steady-state GA-based approach in terms of number of selected features and the accuracy with selected feature. Result indicates the unsuitability of SVM as wrapper due to large computational cost in comparison to k-NN. Choice of filter algorithm seems to be having no significant effect on classification accuracy obtained using selected features. Comparison in terms of number of selected features and the accuracy with selected features suggests comparable performance by both wrapper–filter and steady-state GAs for the used data set.     

Fractal dimension analysis for quantifying cerebellar morphological change of multiple system atrophy of the cerebellar type (MSA-C)

Multiple system atrophy of the cerebellar type (MSA-C) is a degenerative neurological disease of the central nervous system. This study aims to demonstrate that the morphological changes of cerebellar structure, specifically, the cerebellum white matter (CBWM) and cerebellum gray matter (CBGM) from T1-weighted magnetic resonance (MR) images, can be quantified by three-dimensional (3D) fractal dimension (FD) analysis, which is a measure of complexity. Twenty-three MSA-C patients and twenty-one normal subjects participated in this study. The results of this study show that MSA-C patients presented significantly lower FD values compared to the control group, and that morphological change in the CBWM dominates the cerebellar degeneration. In addition, the FD analysis method is superior to conventional volumetric methods in quantifying the structural changes of WM and GM because it exhibits smaller variances and less gender effect. Since a decrease of cerebellar FD value indicates degeneration of the cerebellar structure, this study further suggests that the morphological changes of cerebellar structures (CBGM and CBWM) can be characterized by FD analysis.     

Adjustment of blood pressure data by season

Seasonal variation in blood pressure was examined in 801 males of age 50 years and over. Systolic and diastolic pressures revealed significant seasonal patterns with peaks in spring and late autumn and troughs in mid-winter and summer. The blood pressure data standardized for age and body weight (kg/m2) and adjusted for irregular fluctuations showed that the range of variation in systolic pressure within a year was 8-9 mmHg and that in diastolic pressure 5 mmHg. Careful analysis of the data indicates that the variations in blood pressure attributable to the month of the year are at least as significant as those due to age and body weight. An example is drawn from an actual study which demonstrates how estimates of the prevalence of hypertension may be substantially biased if the seasonal pattern in blood pressure is not taken into account. It is therefore suggested that this factor should be allowed for routinely, at least in local epidemiological surveys, in addition it should be recognised as important in daily clinical work--especially in those patients who are in need of antihypertensive treatment.