检索结果-南通市图书馆

Investigation of changes in thickness and reflectivity from layered retinal structures of healthy and diabetic eyes with optical coherence tomography

引用

Journal of Biomedical Science and Engineering 2011年第10期4卷 657-665页

作者： Wei Gao Erika Tatrai Veronika Olvedy Boglarka Varga Lenke Laurik Aniko Somogyi gabor mark somfai Delia Cabrera DeBuc Bascom Palmer Eye Institute University of Miami Miller School of MedicineMiamiUSA Semmelweis University Department of OphthalmologyBudapestHungary Semmelweis University 2^(nd) Department of Internal MedicineBudapestHungary

OCT is usually employed for the measurement of retinal thickness. However, coherent reflected light carries more information characterizing the optical properties of tissue. Therefore, optical property changes may provide further information regarding cellular layers and early damage in ocular diseases. We investigated the possibility of OCT in detecting changes in the optical backscattered signal from layered retinal structures. OCT images were obtained from diabetic patients without retinopathy (DM, n = 38 eyes) or mild diabetic retinopathy (MDR, n = 43 eyes) and normal healthy subjects (n = 74 eyes). The thickness and reflectivity of various layered structures were assessed using a custom-built algorithm. In addition, we evaluated the usefulness of quantifying the reflectivity of layered structures in the detection of retinal damage. Generalized estimating equations considering within-subject inter-eye relations were used to test for differences between the groups. A modified p value of <0.001 was considered statistically significant. Receiver operating characteristic (ROC) curves were constructed to describe the ability of each parameter to discriminate between the eyes of DM, MDR and healthy eyes. Thickness values of the GCL + IPL and OPL showed a significant decrease in the MDR eyes compared to controls. Significant decreases of total reflectance average values were observed in all layers in the MDR eyes compared with controls. The highest AUROC values estimated for the total reflectance were observed for the GCL+IPL, OPL and OS when comparing MDR eyes with controls. Total reflectance showed a better discriminating power between the MDR eyes and healthy eyes compared to thickness values. Our results suggest that the optical properties of the intraretinal layers may provide useful information to differentiate pathological from healthy eyes. Further research is warranted to determine how this approach may be used to improve diagnosis of early retinal neurodegene

关键词： Optical Coherence Tomography Rerina Diabetic Retinopathy Segmentation Image Processing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparison of Traditional and WEB-Based Education-Case Study “BigBlueButton”

Comparison of Traditional and WEB-Based Education-Case Study...

引用

2012 International Symposium on Information Technologies in Medicine and Education(ITME2012)

作者： gabor Kiss Department of Mechatronics and Cartechnics Engineering óbuda University Bécsi ut 96/b BudapestHungaryH-1034

The goal of this research was an analysis of the paper results in two groups of students in second semester to see the result of an earlier research was correct or *** the first group I made the presentation of the lectures virtual by using the BigBlueButton web conference system（n=118）while the lectures for the second group were delivered in class（traditional way,n=171）.The experience shows,the majority of the students do not visit the presentations at the universities,just download the learning material and try to take a successful exam,but they do not have too much chance to pass *** of all I wanted to see how many students take part in the virtual and traditional presentations respectively in the next semester and I observed that the virtual way was preferred（～80%of students）to the classical way（～30-40%）,I got same result like in the first *** students in the first group were more motivated;they took this opportunity rather than the conventional educational *** starting hypothesis was that the group where I used the web conference system as a presentation tool would achieve better results in the *** was based on the differentiation of the number of participants at the presentations,because more students visited the virtual presentations and followed the lessons over the *** the evaluation of the final tests results the correctness of the original presumption seemed to be *** level was 5%through the *** was found significant divergence in the knowledge of the students taking part in the virtual presentations and that of the students using the traditional *** students could get one mark better paper results when they followed the virtual lesson.I made this research with partly other students and I get same ***,the use of the web conference system as a presentation tool is productive;the students follow the presentations with more motivation to use this new tool in their studies and

关键词： comparison web-based education case study virtual classroom virtual lesson traditional education measuring

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Frequency and Energy Difference Detection of Dolphin Biosonar Signals Using a Decomposition Algorithm

引用

Open Journal of Acoustics 2016年第1期6卷 1-12页

作者： mark W. Muller Department of Physics Salisbury University Salisbury MD USA

A set of dolphin echolocation signals previously collected from an Atlantic bottlenose dolphin in Kaneohe Bay, Hawai’i are decomposed using a matching pursuit algorithm to further investigate the role of four types of echolocation signals outlined elsewhere [1]. The method decomposes the echolocation signals into optimal linear expansions of waveforms, which are gabor functions defined in a dictionary. The method allows for study of the changes in frequency content within a dolphin’s functional bandwidth during discrimination tasks. We investigate the role of the functional bandwidth in terms of the signal energy levels and echolocations task performance. Furthermore, ROC analysis is applied to the relative energies of the matched waveforms to determine probability of discrimination. The results suggest that dolphins may discriminate by inspection of the relevant frequency differences between targets. In addition, the results from the ROC analysis provides insight into the role of the different classes of dolphin signals and of the importance of modification of the outgoing echolocation clicks, which may be fundamental to a dolphin’s ability to identify and discriminate targets.

关键词： Dolphin Biosonar Detection Discrimination Decomposition

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：