Brilliance型16排螺旋CT的故障分析与维修

针对日常使用中遇到的Brilliance 16排螺旋CT高压系统、机架以及控制器局域网络(CAN)通讯等故障现象进行分析与维修,最终通过更换滤波电容、机架数据采集控制器(DMC)电源以及信号刷等配件得以排除故障。通过对故障准确判断以及合理运用厂家Service模式下的维修工具软件快速解决故障,保障了影像科检查工作的顺利进行,从而提高设备的稳定性。     

几何不确定性鲁棒优化在肝癌立体定向放疗中的应用

目的:分析基于几何不确定性的鲁棒优化计划对肝癌立体定向放疗（SBRT）剂量分布的影响。方法:选取12例肝癌SBRT患者，对每例制作3个调强计划:①基于PTV（ITV-PTV 5 mm）的常规优化（PTV-Based Plan）；②基于ITV非均匀几何不确定性（本中心计算的不确定性值:进出方向7 mm，左右和前后方向4 mm）的鲁棒优化（Robust Planactual）；③基于ITV均匀5 mm几何不确定性的鲁棒优化（Robust Plan5 mm）。所有计划都以95%的PTV满足处方剂量作为目标，以等中心均匀偏移4、5、7 mm计算扰动剂量评估鲁棒性。结果:计划①②③的均匀性指数（HI）分别为0.083±0.027、0.099±0.035、0.096±0.026，不具有统计学意义；计划①②③的适形性指数（CI）分别为0.98±0.02、1.02±0.05、1.00±0.04，计划②③相对于计划①的CI具有统计学意义。计划③的正常肝组织平均受量和V2500相对于计划①②分别下降了4.1%、2.5%和5.4%、3.0%，且具有统计学意义（P=0.034、P=0.021和P=0.004、P=0.004），计划②相对于计划①的正常肝组织平均受量和V2500不具有统计学意义（P=0.308和P=0.182），但下降了1.6%和2.5%。对于其鲁棒性，计划②③的5 mm-D99%、5 mm-D98%、5 mm-D95%的剂量-体积直方图带宽（DVHBW）差值相对于计划①更小，随着摆位不确定度的增大，其DVHBW差值越大。结论:在肝脏SBRT治疗中，采用鲁棒优化能够提高靶区剂量分布质量，即使在摆位不确定度有所增加的情况下，仍可以保证ITV的剂量覆盖同时不增加正常组织的照射剂量。     

癌症生存者家庭适应相关测量工具的研究进展

介绍家庭适应的相关概念及起源,阐述家庭适应方面常用测量工具的发展历程、内容结构、适用人群、评分方法、信度与效度、应用现状等情况,以期能够指导临床工作者在实践过程中选择合适的家庭适应测量工具,旨在帮助研究者进一步开发适用于我国癌症生存者的特异性家庭适应测量工具。     

淋巴水肿上肢体积测量装置的设计及应用

目的 探讨自行设计的淋巴水肿上肢体积测量装置在测量淋巴水肿患者肢体肿胀程度方面的应用效果。 方法 选择2018年7月至2018年12月在我院淋巴水肿专病门诊就诊的患者70例,按照随机数字表法分为观察组(n=35)和对照组(n=35),观察组采用淋巴水肿上肢体积测量装置评估患者治疗前后患侧肢体的肿胀程度,对照组采用传统的软尺测量+不可擦记号笔做标记的方法测量患者治疗前后患侧肢体的周径变化情况。 结果 满意度评价中观察组的满意率明显高于对照组(P＜0.05),护士操作难易度比较中,观察组护士认为操作简单的频率明显高于对照组(P＜0.05)。 结论 自行设计的淋巴水肿上肢体积测量装置可以提高患者的满意度,方便护士操作,值得临床推广。     

Derivation of occupational exposure limits: Differences in methods and protection levels

Frameworks for deriving occupational exposure limits (OELs) and OEL-analogue values (such as derived-no-effect levels [DNELs]) in various regulatory areas in the EU and at national level in Germany were analysed. Reasons for differences between frameworks and possible means of improving transparency and harmonisation were identified. Differences between assessment factors used for deriving exposure limits proved to be one important reason for diverging numerical values. Distributions for exposure time, interspecies and intraspecies extrapolation were combined by probabilistic methods and compared with default values of assessment factors used in the various OEL frameworks in order to investigate protection levels. In a subchronic inhalation study showing local effects in the respiratory tract, the probability that assessment factors were sufficiently high to protect 99% and 95% of the target population (workers) from adverse effects varied considerably from 9% to 71% and 17% to 87%, respectively, between the frameworks. All steps of the derivation process, including the uncertainty associated with the point of departure (POD), were further analysed with two examples of full probabilistic assessments. It is proposed that benchmark modelling should be the method of choice for deriving PODs and that all OEL frameworks should provide detailed guidance documents and clearly define their protection goals by stating the proportion of the exposed population the OEL aims to cover and the probability with which they intend to provide protection from adverse effects. Harmonisation can be achieved by agreeing on the way to perform the methodological steps for deriving OELs and on common protection goals.     

“The median isn't the message”: How to communicate the uncertainties of survival prognoses to cancer patients in a realistic and hopeful way

This study investigated how doctors communicate the uncertainties of survival prognoses to patients recently diagnosed with life‐threatening cancer, and suggests ways to improve this communication. Two hundred thirty‐eight Norwegian oncologists and general practitioners (GPs) participated in Study 1. The study included both a scenario and a survey. The scenario asked participants to respond to a hypothetical patient who wanted to know how long (s)he could be expected to live. There were marked differences in responses within both groups, but few differences between the GPs and oncologists. There was a strong reluctance among doctors to provide patients with a prognosis. Even when they were presented with a statistically well‐founded right‐skewed survival curve, only a small minority provided hope by communicating the variation in survival time. In Study 2, 177 healthy students rated their preferences for different ways of receiving information regarding the uncertainty of a survival prognosis. Participants who received an explicitly described right‐skewed survival curve believed that they would feel more hopeful. These participants also obtained a more realistic understanding of the variation in survival than those who did not receive this information. Based on the findings of the two studies and on extant psychological research, the author suggests much‐needed guidelines for communicating survival prognoses in a realistic and optimistic way to patients recently diagnosed with life‐threatening cancer. In particular, the guidelines emphasise that the doctor explains the often strongly right‐skewed variation in survival time, and thereby providing the patient with realistic hope.     

Depressive symptoms in caregivers immediately after stroke

Background: Caregivers of stroke survivors often suffer depressive symptoms that interfere with their own health. Early recognition may lead to attenuation of symptoms and better health and well-being for caregivers.

Objective: We examined characteristics of caregivers and stroke survivors associated with caregivers’ depressive symptoms in the early poststroke period.

Methods: We conducted a prospective, longitudinal exploratory observational study with a convenience sample of 63 caregivers of older adult (≥ 65 years) stroke survivors recruited from urban acute-care settings. We enrolled caregivers by 2 weeks poststroke (T1) and revisited them 4 weeks later (T2). Depressive symptoms were measured using the Patient Health Questionnaire-9. A separate unadjusted linear mixed model was computed to explore significant associations between each caregiver or stroke-survivor characteristic and depressive symptoms.

Results: Caregivers, on average, reported mild depressive symptoms at T1 and T2. Each of the following characteristics was independently associated with caregiver depressive symptoms over the first 6 weeks poststroke: caregiver uncertainty (p < 0.001), perceived stress (p < 0.001) but not cortisol levels (p = 0.858 on waking, p = 0.231 evening), coping (p < 0.001), social support (p = 0.006), race (p = 0.022), income (p = 0.001), time spent on care (p = 0.039), and stroke-survivor race (p = 0.033) and functional status (p = 0.003). At T2, caregiver depressive symptoms were correlated with evening cortisol level (p = 0.001).

Conclusions: Caregiver and stroke-survivor characteristics may help identify caregivers at highest risk for early depressive symptoms and guide interventions aimed at their resolution.     

Evaluation of a novel flow-controlled syringe infusion pump for precise and continuous drug delivery at low flow rates: a laboratory study

Syringe infusion pumps are used for the administration of short-acting drugs in anaesthesia and critical care medicine, but are prone to flow irregularities at low flow rates. A flow-controlled syringe infusion pump using an integrated flow sensor for feedback control represents a new approach to overcoming these limitations. This study compares the performance of a prototype flow-controlled syringe pump both at start-up, and during vertical displacement manoeuvres, with that of a standard infusion syringe pump. The novel pump almost completely eliminated delays at start-up and flow irregularities during hydrostatic pressure changes. Related fluctuations in plasma drug concentration were minimised and the known disadvantages of standard syringe infusion pumps currently used in clinical practice were reduced. Besides providing fast start-up to steady-state flow and precise continuous drug delivery at low flow rates during hydrostatic pressure changes, the new pump offers the potential for the development of target-controlled infusion algorithms for short-acting cardiovascular and other drugs.