与高速涡轮牙钻机配套使用的口腔软组织保护器研制与应用

目的设计一种与高速涡轮牙钻机配套使用的口腔软组织保护器,有效隔绝防护高速涡轮牙钻机工作区域的次生损伤。方法本研究中与高速涡轮牙钻机配套使用的口腔软组织保护器由唇颊侧软组织保护器和舌侧软组织保护器两部分组成。结果与高速涡轮牙钻机配套的口腔保护器,能够有效防护高速牙钻机使用产生的各种问题。结论本新型与高速涡轮牙钻机配套使用的口腔软组织保护器达到临床使用的要求。     

管道化涡轮牙钻

涡轮牙钻是牙科治疗中的重要设备,具有转速高、使用方便、病人痛苦少等特点。为了提高工作效率,节约能源,我们在有关单位的帮助下,设计、安装了管道化涡轮牙钻,即各涡轮牙钻间以管道相连,由一台大功率空气压缩机供气运转。与一机一泵的单台涡轮牙钻相比,具有结构简单、费用低廉、效果稳定、维修方便等优点。管道化涡轮牙钻是一个机、管系统,由各台单机和提供压缩空气的气路、提供冷却水的水路以及吸唾液的真空路组成(见图1)。     

“涡轮排风机”通风除尘效果评价

二氧化碳气体保护焊接在汽车制造业中应用较普及。由于作业范围广、流动性大且手工操作等原因,使其在焊接过程中产生的焊接烟尘和部分有害气体一直缺乏有效的防护措施。为了有效控制粉尘浓度和改善工人的劳动环境,扬州通华专用车有限公司引进新的防尘技术：应用“涡轮排风机”装置进行通风除尘和净化车间空气。为了解其防护效果,我们进行了现场电焊烟尘浓度测定和卫生学评价。１“涡轮排风机”通风隆尘工作机理 涡轮排风机由流体力学专家精密计算并经过实际测试与比较设计而成。其顶盖、叶片及外环,使用经阳极处理的铝合金、不锈钢及烤…     

二氧化碳保护焊接中应用“涡轮排风机”的降尘效果评价

二氧化碳气体保护焊接在汽车制造业中应用较普及。由于作业范围广、流动性大且手工操作等原因,使其在焊接过程中产生的焊接烟尘和部分有害气体一直缺乏有效的防护措施。为了有效控制粉尘浓度和改善工人的劳动环境,扬州通华专用车有限公司引进新的防尘技术:应用“涡轮排风机”装置进行通风除尘和净化车间空气。为了解其防护效果,我们进行了现场电焊烟尘浓度测定和卫生学评价。 1 “涡轮排风机”通风降尘工作机理 涡轮排风机由流体力学专家精密计算并经过实际测试与比较设计而成。其顶盖、叶片及外环,使用经阳极处理的铝合金、不锈钢及烤漆板制品,将其按要求安装于车间顶部,见图1,只     

T-BIRD呼吸机故障检修一例

工作原理:T-Bird呼吸机的组成主要包括电路部分、气动部分和操作控制面板。电路部分和操作控制面板对呼吸机的整个工作过程起到控制、监测、显示、参数调节设定及报警等功能,气路部分采用鸟牌呼吸机专利——涡轮。涡轮代替传统压缩机,其反映速度快,主板根据设定的参数发指令给涡轮驱动板,控制涡轮自动增加或减少涡轮的转速,该转速与涡轮EPROM内数据比对以达到平稳送气的目的。呼吸机开机进行5S自检,通过后,呼吸机转入正常工作状态。     

应用高速涡轮手机分牙拔除阻生智齿124例临床体会

目的：为了进一步探讨应用高速涡轮手机拔除阻生智齿临床实际效果,并与传统的拔牙方法的临床效果进行对比,从而为相关研究提供借鉴和参考。方法：选取2010年12月-2012年12月本院收治的阻生智齿患者124例为研究对象进行了回顾性研究。将患者按随机随机数字表法将患者分为传统拔牙组（n=62）和高速涡轮手机组（n=62）,比较两组相关临床指标。结果：（1）在拔牙时间、肿胀度、张口受限度、拔牙窝完整性上,高速涡轮手机组均显著优于传统拔牙组（P〈0.05）;（2）高速涡轮手机组的心理畏惧情况显著优于传统拔牙组（P〈0.05）;（3）高速涡轮手机组的临床满意度显著高于传统拔牙组（P〈0.05）。结论：在临床拔除阻生智齿的实践过程中,采用高速涡轮手机的方法进行治疗的临床效果显著,是临床除阻生智齿的可靠选择。     

口腔软组织保护器预防组织损伤的临床研究

目的:设计一种与高速涡轮牙钻机配套使用的口腔软组织保护器,分析其应用价值,为解决高速牙钻机临床使用中产生的系列问题提供新思路。方法:研制新型与高速涡轮牙钻机配套使用的口腔软组织保护器,选择需要高速涡轮牙钻机治疗的下颌阻生齿患者作为研究对象,随机分为给予常规操作的对照组和配备新型口腔软组织保护器的观察组,观察两组患者接受高速涡轮机治疗时出现的口腔内邻牙、粘膜、牙龈等组织损伤的情况。结果:观察组配备口腔软组织保护器后出现的周围组织损伤情况明显较对照组改善(x2值28.2x20.05,1,P0.05)。结论:新型口腔软组织保护器与高速涡轮牙钻机配套使用后,可有效防护高速涡轮牙钻机工作区域的组织损伤,具有较高的应用价值。     

高速涡轮牙钻切割与骨凿法联合拔除下颌阻生智齿的临床应用

目的探索高速涡轮牙钻切割与骨凿法联合拔除下颌阻生智齿的优点,并与单纯高速涡轮牙钻拔除方法进行比较分析。方法对674例下颌阻生智齿随机分为两组,实验组342例采取高速涡轮牙钻切割与骨凿法联合进行拔除,对照组332例采取单纯高速涡轮牙钻方法拔除,观察临床效果,及时记录手术创伤、拔牙时间、术后疼痛的程度、张口受限及干槽症的发生情况。结果实验组手术创伤小,手术时间明显缩短,术后疼痛和张口受限程度及干槽症的发生明显低于对照组。结论高速涡轮牙钻切割与骨凿法联合拔除下颌阻生智齿能明显减轻手术创伤,缩短手术时间,减少术后并发症,值得临床推广应用。     

涡轮钻磨除法在复杂牙拔除中使用的一点体会

目的探讨复杂牙拔除中应用涡轮钻的优点。方法：通过临床收集涡轮钻磨除法拔复杂牙312例的结果,发现涡轮钻磨除法拔除复杂牙时由于视野清楚,对周围组织损伤小,手术时间短,术中术后并发症少,减轻了患者恐惧心理,易为患者接受,值得推广。     

一种伤员后送用液体流速显示装置的研制

目的:研制一种适用于伤员后送途中使用的液体流速显示装置。方法:采用涡轮流量计的原理,进行了3轮图纸设计、样品制作、体外实验。结果:制作出了显示精度能够达到4 mL/min的叶轮式流速显示装置。结论:该流速显示装置具有安全、便携、价格低廉、无需电力支持等特点。它为提高后送输液安全提供了经济实用和便于推广的解决方案。     

Analysis of case-cohort designs

The case-cohort design is most useful in analyzing time to failure in a large cohort in which failure is rare. Covariate information is collected from all failures and a representative sample of censored observations. Sampling is done without respect to time or disease status, and, therefore, the design is more flexible than a nested case-control design. Despite the efficiency of the methods, case-cohort designs are not often used because of perceived analytic complexity. In this article, we illustrate computation of a simple variance estimator and discuss model fitting techniques in SAS. Three different weighting methods are considered. Model fitting is demonstrated in an occupational exposure study of nickel refinery workers. The design is compared to a nested case-control design with respect to analysis and efficiency in a small simulation. In this example, case-cohort sampling from the full cohort was more efficient than using a comparable nested case-control design.     

阶梯设计在随机对照试验中的应用

介绍阶梯设计的基本原理和实施方法,探讨其在随机对照试验中的应用.当研究者希望在一定范围内全面推行某项通常来说"利大于弊"的措施,又想通过随机对照试验来对该措施的效果进行评价,尤其是当资源有限使得本来就只能分步实施干预的时候,阶梯设计非常适用.另外,该方法还可用来发现或控制时间趋势对效果评价的影响.但与传统设计相比,阶梯设计的试验周期更长,统计学问题也要复杂得多.因此,在设计和实施的过程中应严格把握有关注意事项,以保证研究结果的稳健性.     

A plea to stop using the case-control design in retrospective database studies

The case-control design is widely used in retrospective database studies, often leading to spectacular findings. However, results of these studies often cannot be replicated, and the advantage of this design over others is questionable. To demonstrate the shortcomings of applications of this design, we replicate two published case-control studies. The first investigates isotretinoin and ulcerative colitis using a simple case-control design. The second focuses on dipeptidyl peptidase-4 inhibitors and acute pancreatitis, using a nested case-control design. We include large sets of negative control exposures (where the true odds ratio is believed to be 1) in both studies. Both replication studies produce effect size estimates consistent with the original studies, but also generate estimates for the negative control exposures showing substantial residual bias. In contrast, applying a self-controlled design to answer the same questions using the same data reveals far less bias. Although the case-control design in general is not at fault, its application in retrospective database studies, where all exposure and covariate data for the entire cohort are available, is unnecessary, as other alternatives such as cohort and self-controlled designs are available. Moreover, by focusing on cases and controls it opens the door to inappropriate comparisons between exposure groups, leading to confounding for which the design has few options to adjust for. We argue that this design should no longer be used in these types of data. At the very least, negative control exposures should be used to prove that the concerns raised here do not apply.     

多焦视觉电生理检查系统数据库的设计

介绍多焦视觉电生理检查系统的数据库设计，选用Microsoft Access97来设计数据库，VC＋＋通过DA0接口来对数据库进行添加、查询、删除等操作。体现了数据库便于管理、查询方便的优点，其设计模式也可以用于其它医学仪器的设计中。     

基于MSP430F148和CC1100的无线血氧指夹的设计

血氧饱和度探头是对人体基本生理参数进行实时监测的仪器。本设计使得该探头具有实时监测及显示血氧饱和度功能。本文围绕无线血氧指夹的实现和应用两个方面,介绍本设计的软硬件实现方法及设计的应用。     

Optimal designs for estimating the most successful dose

There has been much recent interest in phase I/II dose finding designs in which information on both toxicity and efficacy is used. Unlike the classic phase I dose finding design in which the aim is to identify the MTD (maximum tolerated dose corresponding to some percentile of acceptable toxicity), a phase I/II dose finding study aims to locate the most successful dose (MSD), i.e. the dose which maximizes the product of the probability of seeing no toxicity together with the probability of seeing a therapeutic response). In this work we present an abstract theoretical design for this purpose. We call this design a 'virtual' design. The virtual design, conceptually similar to that developed for phase I designs alone, is based on a bivariate response. The design has optimal properties in that the current estimates of both probability of toxicity and those for response achieve the Cramer-Rao bound for every dose level. Unhappily, the virtual design is not available for practical use but its use can be exploited in theoretical investigations in much the same way as one uses the Cramer-Rao bound for unbiased estimators, i.e. a tool which enables us to see how much room for improvement may exist for any given real design. Via examples taken from the literature on phase I/II dose finding we illustrate how this technique can provide us with further insight on the relative performance of competing designs.     

Limitations of the case-only design for identifying gene-environment interactions

The case-only design, which requires only diseased subjects, allows for estimation of multiplicative interactions between factors known to be independent in the study population. The design is being used as an alternative to the case-control design to study gene-environment interactions. Estimates of gene-environment interactions have been shown to be very efficient relative to estimates obtained with a case-control study under the assumption of independence between the genetic and environmental factors. In this paper, the authors explore the robustness of this procedure to uncertainty about the independence assumption. By using simulations, they demonstrate that inferences about the multiplicative interaction with the case-only design can be highly distorted when there is departure from the independence assumption. They illustrate their results with a recent study of gene-environment interactions and risk of lung cancer incidence in a cohort of miners from the Yunnan Tin Corporation in southern China. Investigators should be aware that the increased efficiency of the case-only design is a consequence of a strong assumption and that this design can perform poorly if the assumption is violated.     

The 2 x 2 factorial design: its application to a randomized trial of aspirin and carotene in U.S. physicians

The 2 x 2 factorial design calls for randomizing each participant to treatment A or B to address one question and further assignment at random within each group to treatment C or D to examine a second issue, permitting the simultaneous test of two different hypotheses. This design can increase the efficiency of large-scale clinical trials. The Physicians' Health Study, a randomized trial of aspirin and beta-carotene among U.S. physicians, illustrates some features and potential problems in the design and analysis of a factorial trial. The most common concern, interaction between treatments, is generally an advantage rather than a limitation of this design. Although such interactions are relatively uncommon, this design provides a means to measure an effect which otherwise might not be apparent. If the interaction is sufficiently severe, however, then loss of power is possible.     

An audience-channel-message-evaluation (ACME) framework for health communication campaigns

Recent reviews of the literature have indicated that a number of health communication campaigns continue to fail to adhere to principles of effective campaign design. The lack of an integrated, organizing framework for the design, implementation, and evaluation of health communication campaigns may contribute to this state of affairs. The current article introduces an audience-channel-message-evaluation (ACME) framework that organizes the major principles of health campaign design, implementation, and evaluation. ACME also explicates the relationships and linkages between the varying principles. Insights from ACME include the following: The choice of audience segment(s) to focus on in a campaign affects all other campaign design choices, including message strategy and channel/component options. Although channel selection influences options for message design, choice of message design also influences channel options. Evaluation should not be thought of as a separate activity, but rather should be infused and integrated throughout the campaign design and implementation process, including formative, process, and outcome evaluation activities. Overall, health communication campaigns that adhere to this integrated set of principles of effective campaign design will have a greater chance of success than those using principles idiosyncratically. These design, implementation, and evaluation principles are embodied in the ACME framework.     

Driver perception response time during the signal change interval

The importance of perception response time (PRT) values for traffic signal change interval design, and the need to monitor the design PRT value, are challenges facing transportation professionals. However, current methods used to validate the design PRT value from on-site observational studies have failed to yield convincing proof that the 1 second design value is adequate. A modification to on-site data capture and extraction, using a transitional zone (TZ), is used to overcome this deficiency. The TZ allows the systematic identification and exclusion of those drivers who have time to delay their responses. Their inclusion in past studies inflated PRT values. Their exclusion in this study provides a more accurate value.