自吸过滤式防尘口罩的适合性测试及改进

目的 研究自吸过滤式防尘口罩对中国成年人的适用性,分析影响适合性的主要因素;结合中国人头面特征进行改进,并评价改进后的防护效果.方法 依据前期研究提出的中国人群头面尺寸二元分栏选择代表性测试对象,对市场上购买的杯状(A1)和折叠型(B1)自吸过滤式防尘口罩使用核凝计数器法进行适合性测试.依据中国人头面特征以及适合性影响因素对A1和B1两类自吸过滤式防尘口罩进行改进,并对上述口罩改进后的对应产品A2和B2测定适合性.结果 按适合性因数大于等于100为自吸过滤式防尘口罩的防护效果合格标准,A1型自吸过滤式防尘口罩的通过率为0.0％,适合性因数为20.7(范围:6.9~46.9);B1型自吸过滤式防尘口罩的通过率为4.0％,适合因数为26,0(范围:6.8～154.9).改进后两类自吸过滤式防尘口罩的通过率和适合性因数均提高,A2型自吸过滤式防尘口罩的通过率为72.0％,适合性因数为223.5(范围:2.2～5932.7),与改进前比较,差异有统计学意义(x2=25.09,P＜0.05).B2型的通过率为88.0％,适合性因数为429.8(范围:41.5～3692.9),与改进前比较,差异有统计学意义(x2=32.21,P＜0.05).结论 为保证自吸过滤式防尘口罩的防护效果,其设计需考虑国人脸型特点,劳动者选择自吸过滤式防尘口罩时应进行适合性测定.     

中国成年人呼吸防护用品适合性检验新型头面分栏研究

目的 为满足呼吸防护用品的适配性设计和测试需求,根据目前我国成年人头面测量数据提出2种新的分类(栏)方式:二元分栏和主成分分栏,并分析2种分栏对我国成人头面划分的适用性.方法 以近期我国3000名成年人头面尺寸测量数据为基础建立头面尺寸数据库,根据头面尺寸指标脸长-脸宽的二维分布提出我国成年人头面二元分栏.采用主成分分析对10项稳定的头面尺寸指标(最小额宽、脸宽、鄂宽、脸长、瞳孔间距、头宽、鼻突长、鼻宽、鼻梁宽、鼻长)分析后提出我国成年人头面主成分分栏.通过我国成年人头面数据在不同分栏的分布比例分析两类分栏对成人头面划分的适用性.结果 我国成年人头面二元分栏和主成分分栏分别将脸型分为10个型号和8个型号.总覆盖率分别为96.9%(男性95.4%,女性98.4%)和96.5%(男性95.1%,女性98.1%).各型号覆盖比例较为均匀,二元分栏各型号覆盖率在4.6%～21.7%之间,主成分分栏各型号覆盖率在10.4%～14.6%之间.对比分析国外头面分栏方法,美国洛斯阿拉莫斯实验室(LANL)全面罩分栏只能覆盖我国70.9%的人群,且各型号覆盖极不均匀,其中3个型号的覆盖率之和不足1%;美国国家职业安全卫生研究所(NIOSH)研制的二元分栏和主成分分栏能覆盖我国96.4%和95.9%的人群,但各型号分布不均匀,其二元分栏中5个型号仅覆盖6.3%的人群,主成分分栏中3个型号的覆盖率之和为7.2%.结论 根据我国成人头面数据提出的二元分栏和主成分分栏能代表国人头面尺寸分布,比国外分栏更适用.     

呼吸机临床使用全生命周期的管理及维护

目的：探讨临床上最常用的呼吸急救和生命支持设备—呼吸机的管理及维护方法,科学地对呼吸机全生命周期进行管理、维护、维修及质量控制,提高呼吸机使用效率及效果。方法：科学地建立呼吸机引进、管理、维护与维修、报废及质量控制的规章制度,以确保呼吸机服务于临床的全程监控。结果：通过科学地对呼吸机全生命周期管理,使其能够在急救呼吸危重患者上发挥最大的作用。结论：呼吸机全生命周期的管理方法及维护流程,能够改善并提高呼吸机在临床使用质量,延长呼吸机的使用寿命。     

浅谈呼吸机辅助呼吸治疗重度呼吸衰竭的临床体会

目的通过呼吸及辅助呼吸对我院收治的重度呼吸衰竭的患者进行治疗,分析其治疗疗效。方法对比分析法是一种有效的分析方法。该院采用这种方法对自2012年7月—2013年1月收治的40例患有重度呼吸衰竭的患者进行治疗。结果采用呼吸机辅助呼吸治疗的患者病情得到了显著的好转,其机械通气时间的长短与血气指标成正比。采用常规方法治疗的患者随着治疗时间的延长有时会出现副作用。两组患者之间对比具有显著的统计学意义。结论采用呼吸机辅助呼吸治疗在我院取得了良好的临床实践效果,不仅提高了治疗效率还缩短了治疗时间,具有显著的医学价值与意义。     

呼吸机氧气转接头的设计与临床应用

目的：研制两种氧气转接头,在不改变呼吸机氧气连接装置的情况下,实现中心供氧系统不同终端插座之间的快速转换使用,解决临时更换呼吸机氧气连接装置的困难。方法：设计一种双卡套式连接结构,两端分别连接终端插座和氧气插头,构成简单实用的氧气转接头。结果：制作的两种氧气转接头实现呼吸机与不同氧气终端插座无缝衔接,安装时间只需数秒。结论：应用转接头实现呼吸机在医院范围内快速调配,解决了氧气插头与插座不匹配的问题,同时节省了大量资金     

Recommended test methods and pass/fail criteria for a respirator fit capability test of half-mask air-purifying respirators

This study assessed key test parameters and pass/fail criteria options for developing a respirator fit capability (RFC) test for half-mask air-purifying particulate respirators. Using a 25-subject test panel, benchmark RFC data were collected for 101 National Institute for Occupational Safety and Health-certified respirator models. These models were further grouped into 61 one-, two-, or three-size families. Fit testing was done using a PortaCount® Plus with N95-Companion accessory and an Occupational Safety and Health Administration-accepted quantitative fit test protocol. Three repeated tests (donnings) per subject/respirator model combination were performed. The panel passing rate (PPR) (number or percentage of the 25-subject panel achieving acceptable fit) was determined for each model using five different alternative criteria for determining acceptable fit.

When the 101 models are evaluated individually (i.e., not grouped by families), the percentages of models capable of fitting >75% (19/25 subjects) of the panel were 29% and 32% for subjects achieving a fit factor ≥100 for at least one of the first two donnings and at least one of three donnings, respectively. When the models are evaluated grouped into families and using >75% of panel subjects achieving a fit factor ≥100 for at least one of two donnings as the PPR pass/fail criterion, 48% of all models can pass. When >50% (13/25 subjects) of panel subjects was the PPR criterion, the percentage of passing models increased to 70%.

Testing respirators grouped into families and evaluating the first two donnings for each of two respirator sizes provided the best balance between meeting end user expectations and creating a performance bar for manufacturers. Specifying the test criterion for a subject obtaining acceptable fit as achieving a fit factor ≥100 on at least one out of the two donnings is reasonable because a majority of existing respirator families can achieve an PPR of >50% using this criterion. The different test criteria can be considered by standards development organizations when developing standards.     

呼吸机主要性能指标的质量控制技术

目前呼吸机的临床应用越来越广泛，各医院对所购进呼吸机的性能判定通常是依据设备供应商提供的技术指标，医院缺乏自己的检测和判定设备技术性能的方法和设备。采用呼吸机的质量监测技术，提出对潮气量调节范围、分钟最大通气量、输出气体最低氧浓度、呼吸频率范围、呼吸比、最大安全压力等技术参数进行检测的方法和技术性能要求，可以客观评价呼吸机的主要技术指标，保证临床安全、准确地使用呼吸机。     

BMD-2放射治疗模拟机故障维修3例

BMD-2型模拟机是按等中心原理设计的放射治疗模拟系统,采用透视和照相的方法,对肿瘤患者实施肿瘤的精确定位,为放疗计划提供准确和详细的资料。模拟机在使用中难免会出现各种问题,从而影响放疗定位工作的正常开展。一旦出现故障,如何尽快排除,值得维修人员思考、探讨和总结。     

接锰工人计算机神经行为测试探讨

目的通过使用中文版计算机神经行为评价系统(NES-C3)项目的测试,探讨锰对职业接触工人神经行为的影响.方法以100名接锰工人和26名非接锰工人为测试对象,然后选取11个行为测试项目进行测试.将接锰工人按累积暴露指数(CEI)大小分为低暴露组(CRI＜5)与高暴露组(CEI≥5),每名工人由专业人员单独测试.结果暴露组工人的行为如情绪、符号译码、视简单反应时、目标追踪得分,与对照组相比已有明显改变(P＜0.05).相关分析发现神经行为功能改变与锰累积暴露剂量之间存在剂量效应关系.结论长期接触锰可引起职业接触工人情感状态、心理运动能力、手眼协调能力的改变.计算机神经行为测试可作为一种检测职业接锰工人神经系统亚临床损害的较理想的方法.     

接触苯系物作业人员血常规检查结果分析

目的探讨工龄、年龄、性别等对接触苯系物作业人员血常规检查结果的影响,以减少对苯系物作业人员的健康危害。方法收集2011年1月—2013年12月1 734名接触苯系物作业人员健康监护资料,应用SPSS 13.0统计软件进行数据的处理与分析,采用χ2检验,以P0.05为差异有统计学意义。结果不同年龄组、工龄组及性别组接触苯系物作业人员血常规异常检出率差异有统计学意义(P0.05)。结论工龄、年龄、性别对接触苯系物作业人员的血常规检查结果均有一定影响,且女工较男工更易受到危害。     

基层卫生人员医疗卫生知识水平测试分析

目的分析基层卫生人员医疗卫生知识测试成绩,为提高基层卫生人员素质能力提供参考依据。方法于2011年5—6月对山东、吉林、安徽、陕西及重庆5省(直辖市)的850名基层卫生人员进行基本医疗卫生知识的闭卷笔试,对测试平均分和及格率进行统计描述和单因素分析。结果医生平均分为(60.13±9.30)分,护士平均分为(61.69±9.38)分,防保人员平均分为(63.49±10.01)分;学历水平越高的医生测试成绩越好,工作6～15年的卫生人员成绩较好。结论基层卫生人员对医疗卫生知识掌握水平较差,可通过吸引高校毕业生到基层就业及进行有针对性的在职培训等措施提高卫生人员的整体素质。     

激光作业人员行为功能的研究

本文选择中国科学院安徽光学精密机械研究所68名激光作业人员,进行了成套的神经行为功能测验。结果表明,长期接受激光的散射、漫反射,可使激光作业人员记忆、领悟、视觉感如、视觉反应速度及操作灵敏度、速度、眼手协调功能测验和情绪状态得分明显降低。提示激光对人体神经系统确有明显早期损害,建议神经行为功能测验有可能作为亚临床的早期检测指标。     

The education and practice program for medical students with quantitative and qualitative fit test for respiratory protective equipment

Tuberculosis infection is prevalent in Korea and health care workers are vulnerable totuberculosis infection in the hospital. The aims of this study were to develop andvalidate an education program that teaches senior medical students how to wear and choosethe proper size and type of respiratory protective equipment (RPE), which may help reducethe risk of contracting Mycobacterium tuberculosis (MTB)from patients. Overall, 50 senior medical students participated in this education program.Methods of choosing the proper type of RPE, performing a fit check of the RPE, andchoosing a suitable mask size were taught by certified instructors using the real-timequantitative fit test (QNFT). The validity of education program was evaluated withqualitative fit test (QLFT) before and after the education as pass or fail. The educationprogram was effective, as shown by the significantly pass rate (increased 30 to 74%) inthe QLFT after the education program (p<0.05). Amongstudy participants, changing mask size from medium to small significantly increased thepass rate (p<0.001). Incorporation of this program intothe medical school curriculum may help reduce risk of MTB infection in medical studentsworking in the hospital.     

Two‐part test of vaccine effect

Vaccine benefit is usually two‐folded: (i) prevent a disease or, failing that, (ii) diminish the severity of a disease. To assess vaccine effect, we propose two adaptive tests. The weighted two‐part test is a combination of two statistics, one on disease incidence and one on disease severity. More weight is given to the statistic with the larger a priori effect size, and the weights are determined to maximize testing power. The randomized test applies to the scenario where the total number of infections is relatively small. It uses information on disease severity to bolster power while preserving disease incidence as the primary interest. Properties of the proposed tests are explored asymptotically and by numerical studies. Although motivated by vaccine studies, the proposed tests apply to any trials that involve both binary and continuous outcomes for evaluating treatment effect. Published 2015. This article is a US Government work and is in the public domain in the USA.     

天然胶乳橡胶避孕套国家比对试验经验交流

目的:对天然胶乳橡胶避孕套国家比对试验检测进行经验交流.方法:检验方法依据GB75442009 <天然乳胶橡胶避孕套技术要求试验方法>及作业指导书的要求进行.爆破体积和压力试验使用仪器为:避孕套爆破容量压力测试仪(生产商:瑞典瓦兰德公司,规格型号:M301,精度:±1.0% );针孔试验使用仪器为:充水测漏仪(生产商:瑞典瓦兰德公司).     

Estimation of P‐value of MAX test with double triangle diagram for 2 × 3 SNP case‐control tables

Single nucle otide polymorphisms (SNPs) are the most popular markers in genetic epidemiology. Multiple tests have been applied to evaluate genetic effect of SNPs, such as Pearson's test with two degrees of freedom, three tests with one degree of freedom (χ² tests for dominant and recessive modes and Cockran‐Armitage trend test for additive mode) as well as MAX3 test and MAX test, which are combination of four tests mentioned earlier. Because MAX test is a combination of Pearson's test of two degrees of freedom and two tests of one degree of freedom, the probability density function (pdf) of MAX statistics does not match pdf of χ² distribution of either one or two degrees of freedom. In order to calculate P‐value of MAX test, we introduced a new diagram, Double Triangle Diagram, which was an extension of de Finetti diagram in population genetics which characterized all of the tests for 2 × 3 tables. In the diagram the contour lines of MAX statistics were consisted of elliptic curves and two tangent lines to the ellipses in the space. We normalized the ellipses into regular circles and expressed P‐value of MAX test in an integral form. Although a part of the integral was not analytically solvable, it was calculable with arbitrary accuracy by dividing the area under pdf into finite rectangles. We confirmed that P‐values from our method took uniform distribution from 0 to 1 in three example marginal count sets and concluded that our method was appropriate to give P‐value of MAX test for 2 × 3 tables. Genet. Epidemiol. 34:543–551, 2010. © 2010 Wiley‐Liss, Inc.     

口腔脱落细胞微核技术在丙烯腈接触人群中的应用

目的探讨口腔脱落细胞微核技术在接触丙烯腈人群遗传损伤监护中的应用价值。方法选择生产过程中接触不同浓度丙烯腈的2个工厂工人为接触组,按空气中丙烯腈浓度高低分为低浓度组(41名男性工人)和中浓度组(47名男性工人),另选择不接触任何毒物的男性工人31名为对照组,分别进行口腔黏膜脱落细胞微核和外周血淋巴细胞微核测试。结果2个丙烯腈接触组的口腔黏膜脱落细胞微核率(低浓度组:3.68‰±2.72‰;中浓度组:4.00‰±2.38‰)明显高于对照组(2.03‰±2.20‰),中浓度接触组的血淋巴细胞微核率(4.23‰±3.34‰)明显高于对照组(2.48‰±1.46‰),差异均有统计学意义(P<0.05)。在丙烯腈接触人群中,口腔黏膜脱落细胞微核试验和外周血淋巴细胞微核试验有相关关系(r=0.299~0.359,P<0.05)。结论在丙烯腈接触人群遗传损伤监护时,可用口腔黏膜脱落细胞微核试验代替外周血淋巴细胞微核试验作为筛查指标之一。     

A boundary‐optimized rejection region test for the two‐sample binomial problem

Testing the equality of 2 proportions for a control group versus a treatment group is a well‐researched statistical problem. In some settings, there may be strong historical data that allow one to reliably expect that the control proportion is one, or nearly so. While one‐sample tests or comparisons to historical controls could be used, neither can rigorously control the type I error rate in the event the true control rate changes. In this work, we propose an unconditional exact test that exploits the historical information while controlling the type I error rate. We sequentially construct a rejection region by first maximizing the rejection region in the space where all controls have an event, subject to the constraint that our type I error rate does not exceed α for any true event rate; then with any remaining α we maximize the additional rejection region in the space where one control avoids the event, and so on. When the true control event rate is one, our test is the most powerful nonrandomized test for all points in the alternative space. When the true control event rate is nearly one, we demonstrate that our test has equal or higher mean power, averaging over the alternative space, than a variety of well‐known tests. For the comparison of 4 controls and 4 treated subjects, our proposed test has higher power than all comparator tests. We demonstrate the properties of our proposed test by simulation and use our method to design a malaria vaccine trial.     

A studentized permutation test for three‐arm trials in the ‘gold standard’ design

The ‘gold standard’ design for three‐arm trials refers to trials with an active control and a placebo control in addition to the experimental treatment group. This trial design is recommended when being ethically justifiable and it allows the simultaneous comparison of experimental treatment, active control, and placebo. Parametric testing methods have been studied plentifully over the past years. However, these methods often tend to be liberal or conservative when distributional assumptions are not met particularly with small sample sizes. In this article, we introduce a studentized permutation test for testing non‐inferiority and superiority of the experimental treatment compared with the active control in three‐arm trials in the ‘gold standard’ design. The performance of the studentized permutation test for finite sample sizes is assessed in a Monte Carlo simulation study under various parameter constellations. Emphasis is put on whether the studentized permutation test meets the target significance level. For comparison purposes, commonly used Wald‐type tests, which do not make any distributional assumptions, are included in the simulation study. The simulation study shows that the presented studentized permutation test for assessing non‐inferiority in three‐arm trials in the ‘gold standard’ design outperforms its competitors, for instance the test based on a quasi‐Poisson model, for count data. The methods discussed in this paper are implemented in the R package ThreeArmedTrials which is available on the comprehensive R archive network (CRAN). Copyright © 2016 John Wiley & Sons, Ltd.     

Cross-cultural validity of the demand-control questionnaire: Swedish and Brazilian workers

OBJECTIVE

To evaluate the cross-cultural validity of the Demand-Control Questionnaire, comparing the original Swedish questionnaire with the Brazilian version.

METHODS

We compared data from 362 Swedish and 399 Brazilian health workers. Confirmatory and exploratory factor analyses were performed to test structural validity, using the robust weighted least squares mean and variance-adjusted (WLSMV) estimator. Construct validity, using hypotheses testing, was evaluated through the inspection of the mean score distribution of the scale dimensions according to sociodemographic and social support at work variables.

RESULTS

The confirmatory and exploratory factor analyses supported the instrument in three dimensions (for Swedish and Brazilians): psychological demands, skill discretion and decision authority. The best-fit model was achieved by including an error correlation between work fast and work intensely (psychological demands) and removing the item repetitive work (skill discretion). Hypotheses testing showed that workers with university degree had higher scores on skill discretion and decision authority and those with high levels of Social Support at Work had lower scores on psychological demands and higher scores on decision authority.

CONCLUSIONS

The results supported the equivalent dimensional structures across the two culturally different work contexts. Skill discretion and decision authority formed two distinct dimensions and the item repetitive work should be removed.