【摘要】 目的 分析护理基本技能考核评分误差产生的原因。 方法 使用单因素方差分析法对我校高中起点三年制护理专业2006级440名学生及2007年某校护理专业高中起点三年制护理专业2006级281名学生的护理基本技能考核成绩进行分析，并从2006级440名学生中随机抽取129名学生利用自制问卷进行调查。 结果 考核项目和监考教师不同是造成学生护理基本技能考核成绩评分存在误差的主要原因。 结论 监考教师应统一并细化考核标准及制定护理基本技能考核项目难度系数。【Abstract】 Objective To analyze the reasons of grading error in nursing basic technique examination. Methods The results of nursing basic technique examination of 440 three-year-college students in grade 2006 majored in nursing in Cangzhou Medical College and 281 three-year-college students in grade 2007 majored in nursing in Hebei Provincial Medical College were retrospectively analyzed by one-factor analysis of variance, and 129 students who were selected randomly from the students in grade 2006 were investigated via a self-made questionnaire. Results The reasons of grading error were different assessment items and different invigilators. Conclusion Unifying the difficulty level and the standard of the assessment may decrease the grading errors in nursing basic technique examination.
As a valid method in systematic review, dose-response meta-analysis is widely used in investigating the relationship between independent variable and dependent variable, and which usually based on observational studies. With large sample size, observational studies can provide a reasonable amount of statistical power for meta-analysis. However, due to the design defects of observational studies, they tend to introduce many kinds of biases, which may influence the final results that make them deviation from the truth. Given the dead zone of methodology, there is no any bias adjusting method in dose-response meta-analysis. In this article, we will introduce some bias adjusting methods from other observational-study-based meta-analysis and make them suit for dose-response meta-analysis, and then compare the advantages and disadvantages of these methods.
Because of the long acquisition time and spin-echo planar imaging sequence, diffusion weight magnetic resonance image (DWI) should be denoised effectively to ensure the follow-up applications. The commonly used denoising methods which induced from gray level image lack the use of the specific information from multiple magnitude directions. This paper, therefore, proposes a modified linear minimum mean square error (LMMSE) denosing method used for DWI. The proposed method uses the local information to estimate the parameter of the Rician noise and modifies the LMMSE using the information of multiple magnitude directions synthetically. The simulation and experiment of the synthetic DWI and real human brain DWI dataset demonstrate that the proposed method can more effectively remove the Rician noise compared to the commonly used denoising method and improve the robustness and validity of the diffusion tensor magnetic resonance image (DTI).
【摘要】 目的 利用不同匹配区域对锥形束CT（CBCT）与定位CT（FBCT）分别配准，测量出鼻咽癌放射治疗中颈部的变形误差。 方法 分析2007年4月-2008年12月收治鼻咽癌患者23例，调整治疗床前198次CBCT扫描。将鼻咽部扫描CBCT图像匹配区域分为上下两个区域进行对比分析。其中上匹配区域为:上界为蝶窦上缘，下界为颈4下缘，侧界包括下颌骨外轮廓，前界为上颌窦1/2，后界为平棘突后缘；下匹配区域为:上界约颈4下缘，下界约胸2-3下缘，侧界包括椎体外轮廓，前界包括皮肤，后界平棘突后缘。匹配方式选择骨，比较匹配结果差异。 结果 选择上与下匹配区域结果除Y（头脚）方向旋转误差无统计学差异外，余均有统计学差异（Plt;0.05） 。差值在X（左右）、Z（前后）、Y（头脚）方向平移分别为（1.14±2.80）、（0.47±1.41）、（0.58±3.88） mm，旋转误差X、Y、Z方向分别为（0.90±1.98）、（0.80±2.03）、（0.68±1.90）°。 结论 鼻咽癌放射治疗中颈部区域存在一定变形误差，通过CBCT引导发现变形误差并进行正确纠正是必须的，结合临床实际及靶区与危及器官的变化为重新计划提供依据。【Abstract】 Objective To investigate the rotation errors due to neck deformation in nasopharyngeal cancer (NPC) radiotherapy with different match areas to register conebeam CT(CBCT) from image guiding and fanbeam (FBCT) from simulation. Methods A total of 198 pre-correction CBCT data sets from 23 NPC patients from April 2007 to December 2008 were retrospectively analyzed. The matching areas in CBCT images were divided into up and down region of interest (ROI). For the up ROI, the superior, inferior, left and right, anterior, and posterior boundary were set parallel with sphenoid sinus up side, C4 down side, mandible outside, and 1/2 of maxillary air sinus and acanthi. For the down ROI, the lines were set parallel with C4 down side, T2-3 down side, neck outside, skin surface and acanthi respectively in all directions. All registrations were performed automatically by bony anatomy and the results were compared. Results The registration results by the up and the down ROI showed significant difference except Y direction for rotation. The translation error was (1.14±2.80),(0.47±1.41),and (0.58±3.88) mm, respectively; and the rotation error was (0.90±1.98),(0.80±2.03),and (0.68±1.90) ° in X, Y, and Z direction, respectively. 〖WTHZ〗Conclusions〖WTBZ〗There are some significant deformation errors at neck areas in NPC radiotherapy. It is important to find out the deformation and correct it with CBCT image guiding. This kind of error information may provide clues for re-planning in addition to clinical practice and the changes of clinical targets and involved organs.
Objective To evaluate the accuracy of newer-generation home blood glucose meter (Accu-Check? Integra) in patients with impaired glucose regulation (IGR) and newly-diagnosed type 2 diabetes mellitus. Methods A cross-sectional study was performed on 109 cases with newly-diagnosed type 2 diabetes or IGR who were asked to take oral glucose tolerance test (OGTT), while paired samples, that were Accu-Check? Integra in capillary blood glucose (CBG) and laboratory glucose in venous plasma glucose (VPG ), were taken simultaneously. Taking VPG as the reference value, the accuracy of the home glucose meter was assessed according to the international standardization organization (ISO), including, the accuracy was studied by means of Median absolute difference (Median AD) and Median absolute relative difference (Median RAD), the consistency of CBG and VPG was studied by Clarke Error Grid analysis, the correlation of CBG and VPG was analyzed according to liner regression analysis, and the sensitivity and specificity for hyperglycemia were also calculated. Results There were 292 VPG values paired with CBG values, among which 93.49% of CBG values met ISO home glucose meter criteria, the median AD was 7.2 mg/dL, and the median RAD was 4.76%. Paired glucose measurements from the Accu-Check Integra meter and laboratory glucose measurement demonstrated that 100% of paired points in the overall subject population fell in zones A and B of the Clarke Error Grid. The CBG value was well correlated to VPG value in the overall level, and the sensitivity and specificity were 94.6% and 95.7% respectively for hyperglycemia. Conclusion The newer-generation home blood glucose meter (Accu-Check? Integra) demonstrates a high degree of accuracy, and it can precisely report the real value of blood glucose.
To better use the phase information to compensate the influence of blood flow, the phase unwrapping problem in susceptibility weighted imaging (SWI) is studied in this paper. In order to improve the accuracy of unwrapping, this paper proposes a magnitude image-guided phase unwrapping algorithm of SWI. The basic idea is as follows: (1) reduce the influence of noise by improving the rotational invariant non-local principal component analysis method (PRI-NL-PCA); (2) extract the corresponding solid region in the phase image to avoid the influence of the background noise on the phase unwrapping method; (3) use the phase compensation method to constrain the phase image reconstructed by the K-space. Finally, the reliability of the unwrapping method is evaluated by using four kinds of statistics as quantification index: the number, mean (M), variance (Var), and positive percentage (Pos) and negative percentage (Neg) of phasic error points. By comparing the simulated data with 226 sets of true head SWI data, the results show that the proposed algorithm has high accuracy compared with the classical branch cut method and the least squares method.
Objective To study the comparability of liver function results between the two detection systems. Methods Based on the NCCLS EP9-A document, 8 fresh serum samples were collected daily for the assay of 10 routine liver function parameters by utilizing the Olympus AU1000 and Backman CX7 detection systems respectively. The results were recorded over 5 days consecutively. Linearity equation and relative deviations were calculated. The comparability between the results obtained from different detection systems was evaluated according to the systematic error at medical decision level of CLIA, 88. Results The paired t-test showed that the results of the fresh serum samples had no significant difference between the two detection systems (Pgt;0.05). Except that the systematic error of albumin at low medical decision level exceeded the allowable error, all the other systematic errors at medical decision level were acceptable. Conclusion The results of liver function are comparable between the two detection systems, and the systematic errors between the two detection systems are clinically acceptable.
This is the fifth paper in the evidence-based medicine glossary series. In this paper, we mainly introduce the systematic error（bias）and random error in medical research, review the definition and classification of bias made by different institutions and individuals. We also identify and categorize more than 10 types of bias in systematic review, which are considered the best evidence in evidence-based medicine. Additionally, we introduce some methods to reduce and eliminate bias, explaine six subject headings related to bias in MeSH, and introduce a new glossary — uncertainty in metrology.
Heart rate variability (HRV) analysis technology based on an autoregressive (AR) model is widely used in the assessment of autonomic nervous system function. The order of AR models has important influence on the accuracy of HRV analysis. This article presents a method to determine the optimum order of AR models. After acquiring the ECG signal of 46 healthy adults in their natural breathing state and extracting the beat-to-beat intervals (RRI) in the ECG, we used two criteria, i.e. final prediction error (FPE ) criterion to estimate the optimum model order for AR models, and prediction error whiteness test to decide the reliability of the model. We compared the frequency domain parameters including total power, power in high frequency (HF), power in low frequency (LF), LF power in normalized units and ratio of LF/HF of our HRV analysis to the results of Kubios-HRV. The results showed that the correlation coefficients of the five parameters between our methods and Kubios-HRV were greater than 0.95, and the Bland-Altman plot of the parameters was in the consistent band. The results indicate that the optimization algorithm of HRV analysis based on AR models proposed in this paper can obtain accurate results, and the results of this algorithm has good coherence with those of the Kubios-HRV software in HRV analysis.