除颤分析仪检定结果的不确定度分析评定

目的：通过分析DA-1型除颤分析仪在检定中的不确定度来源,评定和验证除颤能量的不确定度、重复性和稳定性,确保分析仪的质量安全。方法：着重对最大允许误差、能量显示分辨力及释放能量测量重复性3个方面的不确定度来源进行了分析和评定。结果：依据WSB64-2003《心脏除颤器和除颤分析仪检定规程》的各项要求,得出了相应的相对扩展不确定度。结论：经过分析和评定,除颤分析仪的各项不确定度来源的结果符合规程要求,可以检测临床使用的除颤器,确保其质量安全。     

基于三次B样条小波的结肠镜图像暗区中心点估计的研究

提出用三次B样条小波的多尺度边缘检测算子对结肠镜图像的亮度分量Ⅰ进行边缘提取,找出所有类似圆弧状边缘线的圆心经加权求和后得到内窥镜图像暗区真正的中心点,弥补了传统方法中因暗区不明显而无法确定中心点的不足,并用所求的中心点来引导肠镜前端导管,起到导航的作用。     

除颤能量的测量及其结果的不确定度评定在除颤仪质量控制中的应用

目的:研究除颤能量测量及其不确定度评定在除颤仪质量控制中的应用。方法:在技术标准环境条件下测量除颤仪释放的能量,依据JJF 1059—2012《测量不确定度评定与表示》标准规范进行不确定度评定,并依据此不确定度来对除颤仪的质量进行综合评价。结果:除颤仪测量结果的不确定度评定可用于科学评价除颤仪的质量性能,指导医学工程部门进行除颤仪质量控制。结论:对除颤仪释放能量进行不确定度分析与评定,是定量、科学进行质量控制的重要方法,可推广至其他具有量值特性的医疗设备(如呼吸机、输液泵、电子血压计等)的质量控制中。     

数字化γ相机的实时能量校正

介绍了数字化γ相机能量校正表的制作原理,阐述了一种实时能量校正方法,它根据采集事件的位置信息查询能量校正表确定校正单元,取出相邻4个校正单元中的校正量,然后利用双线性插值法得出相应的能量校正系数.最后通过软件编程实现了对采集事件的实时能量校正.     

太空飞行的能量需要量

本文目的旨在探究地面及太空飞行研究中影响机体能量利用和行为的生物化学变化的生理学资料。重点针对阿波罗月球探险、太空实验室扩展太空研究和航天飞机飞行过程中机体对能量的利用。有关飞行及卧床休息过程中的代谢将与胃肠道功能的研究资料一并讨论。人类太空飞行对能量的利用可通过膳食史、代谢平衡实验、食物的消耗量及呼吸气等几种方法间接确定。太空实验室的任务是对与代谢平衡研究密切相关的膳食进行记录。通过2种方法确定太空食品所提供的能量水平,即用弹式热量计直接测定和通过计算碳水化合物、蛋白质和脂肪的摄入量间接确定。用弹式热量计还可直接测定随粪便、尿等排泄的能量,根     

能量鉴别式剂量计在个人剂量监测能力考核中的应用

【目的】了解能量鉴别式剂量计的性能,并分析其对比对个人剂量监测能力考核结果的影响。【方法】对CTLD-J4000型能量鉴别式剂量计进行不同能量光子照射,利用剂量计覆盖的不同密度过滤材料对光子产生不同的过滤作用,拟合读数之比随光子能量的变化曲线来鉴别光子的能量。【结果】鉴别式剂量计读数无过滤/轻过滤比值与厂家参考值的重合性要好于无过滤/重过滤比值,后者在48 keV和83 keV的偏离值较高,分别为12.8%、15.5%。使用平均刻度因子带来的能量响应最大偏差为23.5%。【结论】使用鉴别式剂量计能较好地鉴别出射线能量,从而减少使用平均刻度因子带来的能量响应误差。     

甘油果糖、COA在有机磷中毒治疗中的临床疗效观察

目的评价甘油果糖、COA或含有COA的能量合剂在有机磷中毒治疗中的利弊.方法将随机抽样的方法在89例有机磷中毒患者治疗过程中使用甘油果糖和使用COA或含有辅酶A的能量合剂治疗效果进行比较.结果使用COA或不慎使用COA或含有COA的能量合剂患者、死亡率明显高于对照组.     

心脏除颤仪在生命周期不同阶段的能量释放调查与分析

目的：针对心脏除颤设备的不同生命周期阶段,分析除颤设备能量输出的性能特征,提升管理水平以保证设备使用的安全有效。方法：回顾性分析2015-2022年医院在用(含期间报废设备)的861290、CardioServ等10个型号的90台除颤设备,统计分析除颤设备的能量输出检测数值、计算释放能量误差。将使用初期(设备启用前3年)的36台除颤仪按照年份分为启用第1、2和3年,比较3年设备能量输出数据。将使用正常期(使用中期)数量最多的型号A和型号B除颤仪(41台)依据2018-2000年3年的能量释放校准数据,分析两个型号设备在100 J预置值时释放能量的差异。分析2015-2022年报废期的8台能量输出超限设备的能量释放误差。结果：使用初期3组设备数据,设备启用的第1、2年除颤仪在预置值的能量释放值100、150和200 J比较,差异均无统计学意义(t=-1.17、-0.17、-0.58,P>0.05);设备启用的第1、3年测量值比较,差异均无统计学意义(Z=-0.70、-0.38、-0.86,P>0.05)。在对正常期设备的能量释放重复测量方差分析中,不同型号41台设备在100 ...     

除颤器能量输出失准分析

本文阐述了除颤器能量形成的原理,及与能量输出有关的几个因素,进而使工程技术人员能通过设备使用原理、元器件特性参数以及对设备的检测分析,判定除颤器能量输出失准的原因。     

广东正气：解放思想 以人为本

以5·12地震中心映秀镇为圆心画圆，全国所有省、直辖市中，广东至圆心的半径虽不是最长，但远不是最短——广州至成都的铁路线全长2000多千米。可是，广东省医疗队在这次抗震救灾中，却荣获多项“第一”：第一支进入映秀镇的地方医疗队；第一个成立前线协调组的省医疗队……     

Acceptability of the vaginal sheath (Femshield) in Thai couples

A small survey to assess the perception and experience of current family planning users and their husbands was carried out in a university family planning clinic. Women routinely visiting the clinic were asked to complete a short Screening Form. Fifty-six women responded to the questionnaire concerning their attitude to the Femshield. Eighteen volunteers agreed to enter the study and were given verbal instruction on use of the device. Each volunteer was provided with 3-5 Femshields. Participants were asked to return to the clinic one month after admission. A Husband Form was then sent to the home of the volunteers to assess the attitude of their husbands. Thirteen volunteers returned for the follow-up visit. Fifty Femshields were used. The results showed that the volunteers found the vaginal insertion of the device was acceptable, but the outer and inner rings of the device caused an uncomfortable feeling when having intercourse. The volunteers were more positive to the device than their spouses. The sexual satisfaction of both partners was reduced. A few couples suggested that the device be modified with the bag being smaller and thinner, the outer and inner rings reduced in size and softer, and the device itself being in a prelubricated packet.     

环境镉污染的回顾监测——树木年轮分析

树木年轮分析可用作环境镉污染的回顾监测。结果表明,25年来污染区受到不同程度的镉污染。在树木年轮含镉量与其宽度之间存在明显负相关,含镉量高时,年轮宽度变狭,说明当地镉污染影响了树木的生长。     

Investigating hospital heterogeneity with a competing risks frailty model

Survival analysis is used in the medical field to identify the effect of predictive variables on time to a specific event. Generally, not all variation of survival time can be explained by observed covariates. The effect of unobserved variables on the risk of a patient is called frailty. In multicenter studies, the unobserved center effect can induce frailty on its patients, which can lead to selection bias over time when ignored. For this reason, it is common practice in multicenter studies to include a random frailty term modeling center effect. In a more complex event structure, more than one type of event is possible. Independent frailty variables representing center effect can be incorporated in the model for each competing event. However, in the medical context, events representing disease progression are likely related and correlation is missed when assuming frailties to be independent. In this work, an additive gamma frailty model to account for correlation between frailties in a competing risks model is proposed, to model frailties at center level. Correlation indicates a common center effect on both events and measures how closely the risks are related. Estimation of the model using the expectation-maximization algorithm is illustrated. The model is applied to a data set from a multicenter clinical trial on breast cancer from the European Organisation for Research and Treatment of Cancer (EORTC trial 10854). Hospitals are compared by employing empirical Bayes estimates methodology together with corresponding confidence intervals.     

Decreased survival for childhood leukemia in proximity to television towers

Previously, an increased risk of childhood leukemia was identified among children who resided in an inner ring (radius -4 km) of 3 municipalities surrounding television towers, compared with children who resided in an outer ring (radius approximately 4-12 km) of 6 municipalities surrounding, but farther away from, the towers, which are situated in North Sydney, Australia. In the current study, the authors examined the survival experience of these children for all childhood leukemias, and for acute lymphatic leukemia (International Statistical Classification of Diseases and Related Health Problems, 9th revision [ICD-9] rubric 204.0) in particular. Of 123 cases of acute lymphatic leukemia, 29 cases (16 of whom died) were in the inner ring of municipalities nearest the towers, and 94 cases (34 of whom died) occurred in the outer, more-distant ring. There was a significant difference in survival rates between the 2 groups (log-rank test, p = 0.03; Wilcoxon, p = 0.05). The 5-yr survival in the inner ring of municipalities was 55%, and in the outer ring was 71% (i.e., subjects in the inner ring were 23% less likely to survive than those in the outer ring); at 10 yr, survival in the inner and outer rings was 33% and 62%, respectively. Following adjustment, the mortality rate ratio that the authors used to compare the inner ring with the outer ring was 2.1 (95% confidence interval = 1.1, 4.0). There was an association between residential proximity to the television towers and decreased survival among cases of childhood leukemia in North Sydney, Australia.     

Plasma levels of d-norgestrel and ovarian function in women using intravaginal rings impregnated with dl-norgestrel for several cycles

Silicone polymer intravaginal rings (IVR) of a new “shell” design were used in the present study. The steroid containing part of the rings was impregnated with different amounts of dl-norgestrel. The rings were designed to give two different release rates. Forty-one treatment cycles were studied. The mean plasma level of d-norgestrel, as measured by radioimmunoassay, varied between 2.6 and 0.3 ng/ml. The highest levels were found during the first treatment cycle and declined thereafter. No correlation could be found between the plasma levels of d-norgestrel and the release of d-norgestrel from the rings.Signs of ovulation occurred in 6 (15 %) and breakthrough bleeding or spotting was encountered in 26 (63 %) of the cycles. Breakthrough bleeding and spotting was a constant finding in cycles with a mean plasma level of d-norgestrel below 1.1 ng/ml but never appeared in cycles with a mean level above 1.7 ng/ml. No effects on vaginal flora or the vaginal smear were found.Although the high frequency of bleeding irregularities casts doubt on the acceptability of the IVRs used in this study as a contraceptive method, the study has shown that it is possible to design IVRs capable of releasing dl-norgestrel for several consecutive cycles at fairly constant rates and in amounts sufficient to inhibit ovulation.     

Mercury Distribution in Seawater of Kagoshima Bay near the Active Volcano, Mt. Sakurajima in Japan

Kagoshima bay has a highly active volcano in its center. In the filtered seawater and suspended matter collected from 200-m deep fumaroles at the bottom of the inner bay, the geometric mean concentrations of total mercury were 7.6 and 65.0 ng/L, respectively. The surface seawater collected at the inner bay had a higher concentration of mercury when compared to that in the bay entrance (average: 1.0 vs. 0.5 ng/L). In July, however, no such difference was observed. The fumaroles seem to contribute to relatively high concentrations of mercury in the inner bay except in summer, when thermal cline is formed.     

新医改背景下加强公立医院内涵建设的思路

阐述在新医改背景下公立医院内涵建设的重要性,探讨南方医院加强医院内涵建设的思路和策略:成立客户服务中心,重视患者和内部员工的双重管理;成立健康宣教中心,树立以患者为核心的价值观;实施全程的质量管理,推动医疗质量持续改进。     

Decreased Survival for Childhood Leukemia in Proximity to Television Towers

Previously, an increased risk of childhood leukemia was identified among children who resided in an inner ring (radius ~4 km) of 3 municipalities surrounding television towers, compared with children who resided in an outer ring (radius ~4-12 km) of 6 municipalities surrounding, but farther away from, the towers, which are situated in North Sydney, Australia. In the current study, the authors examined the survival experience of these children for all childhood leukemias, and for acute lymphatic leukemia (International Statistical Classification of Diseases and Related Health Problems, 9th revision [ICD-9] rubric 204.0) in particular. Of 123 cases of acute lymphatic leukemia, 29 cases (16 of whom died) were in the inner ring of municipalities nearest the towers, and 94 cases (34 of whom died) occurred in the outer, more-distant ring. There was a significant difference in survival rates between the 2 groups (log-rank test, p = 0.03; Wilcoxon, p = 0.05). The 5-yr survival in the inner ring of municipalities was 55%, and in the outer ring was 71% (i.e., subjects in the inner ring were 23% less likely to survive than those in the outer ring); at 10 yr, survival in the inner and outer rings was 33% and 62%, respectively. Following adjustment, the mortality rate ratio that the authors used to compare the inner ring with the outer ring was 2.1 (95% confidence interval = 1.1, 4.0). There was an association between residential proximity to the television towers and decreased survival among cases of childhood leukemia in North Sydney, Australia.     

Calculating partial expected value of perfect information via Monte Carlo sampling algorithms.

Partial expected value of perfect information (EVPI) calculations can quantify the value of learning about particular subsets of uncertain parameters in decision models. Published case studies have used different computational approaches. This article examines the computation of partial EVPI estimates via Monte Carlo sampling algorithms. The mathematical definition shows 2 nested expectations, which must be evaluated separately because of the need to compute a maximum between them. A generalized Monte Carlo sampling algorithm uses nested simulation with an outer loop to sample parameters of interest and, conditional upon these, an inner loop to sample remaining uncertain parameters. Alternative computation methods and shortcut algorithms are discussed and mathematical conditions for their use considered. Maxima of Monte Carlo estimates of expectations are biased upward, and the authors show that the use of small samples results in biased EVPI estimates. Three case studies illustrate 1) the bias due to maximization and also the inaccuracy of shortcut algorithms 2) when correlated variables are present and 3) when there is nonlinearity in net benefit functions. If relatively small correlation or nonlinearity is present, then the shortcut algorithm can be substantially inaccurate. Empirical investigation of the numbers of Monte Carlo samples suggests that fewer samples on the outer level and more on the inner level could be efficient and that relatively small numbers of samples can sometimes be used. Several remaining areas for methodological development are set out. A wider application of partial EVPI is recommended both for greater understanding of decision uncertainty and for analyzing research priorities.     

一种基于边缘检测的环状伪影定位算法

目的：提出一种基于边缘检测的环形伪影定位算法,以去除环形伪影。方法：通过含有Sobel算子边缘检测函数提取环形伪影边缘,再采用扫描线法和直线拟合法得到伪影圆的圆心和半径,定位出环形伪影在原始图像中的位置．最后采用线性插值算法对图像进行插值去除伪影。结果：该算法对于实验体模以及临床图像环形伪影去除的效果比较理想。结论：该算法快速有效,减少了运算量,有效地抑制了噪声,提高了环形伪影定位的速度和精度。