改装EcoScreen冷凝器收集机械通气患者呼出气冷凝液的研究

目的探讨设计改装EcoScreen冷凝器收集机械通气患者呼出气冷凝液(EBC)的可行性。方法①体外模拟肺测试:改装EcoScreen冷凝器与模拟肺连接,在干燥呼吸机管道不连接湿化器、连接不加温湿化器、连接加温湿化器三种不同连接状态下机械通气60min,观察气道压和潮气量(VT)的变化,并测量收集冷凝液量。②人体测试:10例患者在干燥呼吸机管道不连接湿化器状态下进行机械通气20min,观察气道压、VT、呼吸频率及心率、血压、SpO2的变化。并测量收集冷凝液量。结果①体外模拟肺测试发现,干燥呼吸机管道不连接湿化器机械通气60min可收集冷凝液2.2mL,期间气道压、VT无明显增高,冷凝器收集管腔无阻塞;连接不加温湿化器,机械通气中VT下降伴气道压升高,50min时被迫中止测试,发现冷凝器收集管腔被冷凝物质明显堵塞,收集冷凝液5mL;连接加温湿化器机械通气60min,收集冷凝液10.5mL,期间气道压轻度升高,VT轻度下降。②人体测试显示,干燥呼吸机管道不连接湿化器,直接与呼吸机相连,机械通气20min可收集冷凝液2mL,收集过程中气道压、VT、呼吸频率及心率、血压和SpO2无显著变化。结论改装EcoScreen冷凝器可用于收集机械通气患者的EBC。为获得检测所需的足量EBC标本,并防止EBC被稀释和气道阻塞,建议脱离湿化器,收集时间20min,同时加强呼吸机和临床监护。     

冷凝器和蒸发器在制冷系统中的作用与保养

冷凝器和蒸发器是制冷系统中重要组成部件，它们的工作状态直接影响着系统的制冷效果，作者从它们的工作原理上分析产生故障的原因及解决的方法，并对如何维护保养好冷凝器和蒸发器作了详细的阐述。     

A Comparative Evaluation of Disposable Humidifiers

The performance of four hygroscopic condenser humidifiers (HCH) and two conventional heat and moisture exchangers (HME), all commercially available, have been evaluated in laboratory tests. A clinical study was also made in order to confirm the test results. It was found that the new generation of heat and moisture exchangers, which have hygroscopic properties, are superior to conventional HME units. When dry inspired gases are used, the HCH units, but not the HME units, deliver a moisture level that is comparable to what is produced in the upper trachea during normal breathing the nose. Our clinical experience as well as the extensive body of literature on humidification requirements support the conclusion that in most cases they can be recommended to be used for extended time periods even with dry gases. The humidification efficiency decreases with increasing tidal volume for all units. However, the best units can be used up to tidal volumes of 1000-1500 ml. The dead space of these units varies from 90 ml to 100 ml and the resistances are only about 50 Pa at 0.5 l/s. The weight is in the range 18-40 g. One of the best HCH devices also has distinct antimicrobial properties. The others are found at least not to promote organism growth. This feature added to others such as safety and simplicity in use make an HCH device an attractive alternative to conventional humidification techniques.     

混合冷凝器的计算

介绍混合冷凝器的计算方法并详细计算示例。     

均匀生物组织的介电常数的测量的一种简易方法

本文介绍了应用平行板电容器测量均匀生物组织的复介电常数的方法和原理     

钛冷凝器失效原因分析及国产化关键技术研究

分析了扬子石化公司PTA生产装置中氧化工段钛冷凝器的失效原因，通过断裂换热管的新口分析确定了钛管失效类型为疲劳断裂，根据列管振动分析计算结果，证实了钛冷凝器在运行过程中确实会产生振动，从而引起钛管疲劳失效。据此，提出了消除振动及改进冷凝器结构的措施，并就国产化制造中的关键技术开展试验与分析研究。     

Laboratory evaluation of heat and moisture exchangers. Assessment of the Draft International Standard (ISO/DIS 9360) in practice

A lung model and test method in accordance with the ISO draft standard for evaluation of heat and moisture exchangers (HME's) was designed. The trial period was 24 h. The moisture-conserving ability of the HME was determined gravimetrically and the temperature performance was calculated from graphs obtained by temperature probes near the two ports of the HME. To determine the reproducibility of the test results, the model was used without an HME and with two HMEs from different manufacturers. The performance values obtained from all three series indicated that the reproducibility of the method was good. The difference between mean inspiration and mean expiration temperatures at the patient port (dTp) provides a useful, simple and reproducible measure of the HMEs' temperature performance. Based on these data, we suggest certain changes in the test procedures outlined in the proposed ISO draft standard.     

The Hygroscopic Condenser Humidifier A new device for general use in anaesthesia and intensive care

The design and performance of the Hygroscopic Condenser Humidifier (HCH) are described. In principle the HCH consists of two parts, a conventional Heat-Moisture-Exchanger (HME) and a hygroscopic unit. The hygroscopic action is shown to improve the water retention efficiency of the device by about a factor of two as compared with optimal HME designs. As a result, humidification levels corresponding to around 80% relative humidity at 37 degrees C are obtained in the trachea and this is also achieved when completely dry gases are delivered to the patient. The unit can therefore be used for all procedures in anaesthesia and in intensive care.     

复杂性热性惊厥儿童视频脑电图及头颅神经影像学特点分析

目的：探讨复杂性热性惊厥(complex febrile seizures, CFS)患儿的视频脑电图及神经影像学特点。方法：选取50例CFS患儿(观察组),并以同期住院的单纯性热性惊厥(simple febrile seizures, SFS)患儿为对照组,对其临床特征、视频脑电图及神经影像学检查结果进行比较。结果：(1)观察组发病前有神经系统异常8例,发作后有神经系统异常表现5例,热性惊厥家族史15例。(2)观察组中视频脑电图(electroence-phalogram, EEG)异常32例,对照组EEG异常14例;观察组32例异常EEG中,痫样放电占28.0%,显著高于对照组(5.0%)。观察组随访1年后,EEG异常者中继发癫痫2例(6.25%)。(3)观察组行头颅CT检查8例(16.0%),头颅磁共振成像(magnetic resonance imaging, MRI)检查42例(84.0%),共发现异常20例(40.0%),显著高于对照组(10.0%)。CT和MRI图像异常率分别为 12.5%和 59.5%,差异有统计学意义。结论：CFS儿童EEG及神经影像学(尤其MRI)异常率高,易发生脑损伤及继发癫痫。在CFS的诊治过程中,有必要个体化选择适合患儿自身的EEG及影像学检查方法,从而有利于临床的早期诊断、早期治疗,有利于长期评估随访。