统计过程控制在医用电子直线加速器机械性能监测中的应用

目的：使用统计过程控制方法分析医用电子直线加速器长期过程表现,监测加速器状态变化趋势,并评估加速器各项指标性能状态。方法：收集2019年6月至2021年4月加速器机器性能检测(MPC)数据。绘制每个机械指标的单值控制图,分析各指标过程特征,并使用过程能力指数C_pk及C_p评估加速器各项机械指标的过程质量。结果：加速器机械精度明显优于当前厂商推荐的规格限值,但控制图监测结果显示各指标均存在一定程度的过程漂移。过程能力分析结果显示所有指标的C_pk及C_p均大于1.33,过程质量优秀。结论：加速器在满足当前MPC规格限的情况下依然可能发生过程失控。统计过程控制方法可及时发现过程中的异常改变,过程能力指数可有效评估过程质量,为质量管理及临床决策提供有效的信息。     

TQA数据趋势与TomoTherapy输出稳定性的联系

目的:探讨TomoTherapy QualityAssurance（TQA）数据趋势与螺旋断层放疗（Helical Tomotherapy,HT）系统输出的联系。方法:回顾性分析了本院HT系统近3年内TQA各个模块的参数和数据趋势,探讨其与HT系统的静态输出剂量和输出能量（D20/D10）变化的相关性。结果:楔形阶梯静态模块的z轴偏移参数与HT的静态输出剂量的相关性最强（r=0.883,P<0.01）。基本剂量测定模块的出口检测器平整度值对能量变化最敏感（r=0.902）,其次是楔形阶梯静态模块的能量差异（r=0.897）和楔形阶梯螺旋模块的能量差异（r=0.852）,灵敏度分别为2.3×10-4、3.1×10-4和5.7×10-4。结论:TQA有助于用户追踪HT输出剂量和能量变化,及早进行必要的机器维护或剂量校准。     

Navigating federalwide assurance requirements when conducting research in community-based care settings

There is an urgent need for research on quality of life and healthcare delivery for older adults living in community-based care settings, yet implementing current federalwide assurance (FWA) requirements can be a challenge in these settings. This paper discusses FWA requirements for engagement in federally funded research as the requirements pertain to community-based care settings. Factors that impede community facilities in achieving FWA approval include lack of organizational structure to provide oversight for the ethical conduct of research, administrator concerns regarding potential liability associated with obtaining the FWA, lack of resources to complete required paperwork, and lack of staff knowledge about human subjects protection and federal requirements for participating in research. Effects of the FWA process on investigators include the burden of extra time needed to support community-based facilities to acquire a FWA and concerns that studies may be limited to only those community facilities with the resources to complete the FWA process. Investigator-initiated strategies for conducting research in community-based settings include considering study designs that are exempt from the FWA process and proactively assisting community-based facilities to acquire FWA status. Investigators need to work with potential research sites and the office for human research protections to ensure that subjects are protected without shifting the burden of protection to ill-prepared community administrators.     

The management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust

Management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust is described. The organisation and input of various stakeholders and their involvement with ultrasound equipment management and scientific ultrasound is discussed. Two important stakeholders are the Medical Equipment Management Group and the Radiation Safety Steering Committee. The Medical Equipment Management Group has a specific sub-group, the Ultrasound sub-group, and its role is to coordinate the purchase, replacement and quality assurance of ultrasound equipment in the Trust. The Radiation Safety Steering Committee has a non-ionising radiation representative and the role of this committee is to provide corporate assurance that any health and safety issues arising from the use of radiation to either patients, members of the public or staff within the Trust are being effectively managed. The Ultrasound sub-group of the Medical Equipment Management Group has successfully brought together management of all ultrasound equipment within the Trust and is in the process of fulfilling the quality assurance and training milestones set out by the Medical Equipment Management Group. Advice from the Radiation Safety Steering Committee has helped to increase awareness of ultrasound safety and good scanning practice, especially in the case of neonatal ultrasound imaging, within the Trust. In addition, the RSSC has given advice on clinical pathways for patients undergoing ionising radiation imaging while being treated by extra-corporeal shockwave lithotripsy.     

The unit of analysis error in studies about physicians’ patient care behavior

Objective:To estimate the frequency with which patients are incorrectly used as the unit of analysis among statistical calculations in published studies of physicians’ patient care behavior. Design:Retrospective review of studies published during 1980–1990. Articles:54 articles retrieved by a computerized search using medical subject beadings for physicians and study characteristics. Article selection criteria included the requirement that the physician should have been the correct unit of analysis. Intervention:Presence of the error was determined by consensus using published criteria. Main results:The error was present in 38 articles (70%). The number of study physicians was reported in 35 articles (65%). The error was found in 57% of articles that reported the number of study physicians and in 95% of those that did not. The error rate was not lower among articles published more recently nor among those published in journals with higher rates of article citations in the medical literature. Conclusion:The unit of analysis error occurs frequently and can generate artificially low p values. Failure to report the number of study physicians can be a clue that this type of error has been made.     

Point‐of‐care testing in haemostasis

Point‐of‐care testing (POCT) in haematology has seen a significant increase in both the spectrum of tests available and the number of tests performed annually. POCT is frequently undertaken with the belief that this will reduce the turnaround time for results and so improve patient care. The most obvious example of POCT in haemostasis is the out‐of‐hospital monitoring of the International Normalized Ratio in patients receiving a vitamin K antagonist, such as warfarin. Other areas include the use of the Activated Clotting Time to monitor anticoagulation for patients on cardio‐pulmonary bypass, platelet function testing to identify patients with apparent aspirin or clopidogrel resistance and thrombelastography to guide blood product replacement during cardiac and hepatic surgery. In contrast to laboratory testing, POCT is frequently undertaken by untrained or semi‐trained individuals and in many cases is not subject to the same strict quality control programmes that exist in the central laboratory. Although external quality assessment programmes do exist for some POCT assays these are still relatively few. The use of POCT in haematology, particularly in the field of haemostasis, is likely to expand and it is important that systems are in place to ensure that the generated results are accurate and precise.     

The establishment of the Australian and New Zealand Neonatal Network

The Australian and New Zealand Neonatal Network was established in 1994 to monitor high-risk newborns admitted for care. Uniquely, all units in both countries have participated since inception, making it integral to the care of babies. The network's objectives include auditing care, publishing aggregated results annually, providing feedback to units, monitoring technologies and developing clinical indicators. Networking provides a forum for clinicians and a consortium of knowledge and advice. It facilitates collaborative research and clinical groups, producing projects from observational studies to randomised controlled trials. Members take a major role in reviewing the evidence for care and ensuring its effective use in clinical practice.     

乳腺X线机辐射源性能检测方法的研究

本文探讨乳腺X线机应用性能的检测方法,重点介绍辐射源性能的检测,包括管电压、管电流和曝光时间的精度和重复性、X线输出量和线性度、半价层和分辨力等参数。