Oscillatory Behavior of Respiratory Gas Exchange in Resting Man

This study deals with the dynamics of respiratory gas carbon dioxide concentration are three, ten, twenty, and thirty to forty-five minutes and two hours; in oxygen concentration, three, ten, twenty, and thirty minutes and one and four hours; and in respiratory quotient, one, five, ten, and fifteen minutes and two to four hours. exchange in resting man. Spectral analyses are performed on time series representing four-hour continuous records of ventilation, carbon dioxide release, oxygen takeup, end tidal carbon dioxide concentration, end tidal oxygen concentration, and respiratory quotient. Results imply that the temporal behavior of each of these six variables can be characterized by a superposition of a finite set of self-sustained almost periodic oscillations with periods in the range from one minute to four hours and time dependent stochastic variation. In ventilation, carbon dioxide release, and oxygen takeup, individual components have amplitudes of between five and ten percent of mean values and nominal periods of one, four, ten, and twenty minutes and one and two to four hours. Components in oxygen concentration, carbon dioxide concentration, and respiratory quotient have amplitudes of between two and four percent of mean values.     

Closed-Loop Control of an Anesthesia Delivery System: Development and Animal Testing

An anesthesia system which integrates closed-loop control of ventilation, oxygen, nitrous oxide, and anesthetic agent delivery into a closed breathing circuit is described. Breathing circuit volume is regulated by controlling the sum of oxygen and nitrous oxide flow, and oxygen concentration in the breathing circuit is regulated by controlling the ratio of oxygen flow to the sum of oxygen and nitrous oxide flow. End-tidal anesthetic agent concentration is regulated by controlling the agent delivery, and end-tidal carbon dioxide concentration is regulated by controlling the ventilation. After tuning the ventilation and anesthetic delivery controllers in preliminary trials in ten dogs, the system was tested and evaluated in five dogs. All control loops were stable and exhibited time responses to step changes in setpoint or external disturbances which were clinically acceptable. The system makes available the advantages of closed-system anesthesia without encumbering the anesthesiologist with the control tasks associated with the technique.     

基于LabVIEW的空芯光子晶体光纤CO2气体检测系统

为了实现全光纤型高灵敏度气体在线检测系统,以空芯光子晶体光纤为传感气室,利用CO2气体分子在1 572.48 nm附近吸收谱以及虚拟仪器LabVIEW平台搭建了双光路差分CO2气体近红外检测实验系统。实验中所用空芯光子晶体光纤长度为1.8 m,通过对其两端同时充气,提高了系统响应速度,0.1 MPa下充气过程仅需100 s左右。以标准浓度CO2气体对该系统进行了标定,并对浓度2%、5%、10%和100%的CO2气体进行了测量,结果表明100 min内浓度检测相对误差不超过2%,标准差最大3.32%。气体吸收光程为1.8 m,系统检测灵敏度达到5.981 810-5 W/ppm。     

乙醇浓度预测的多元线性回归模型建立及验证

设计了由光源、气室、探测器和控制器等组成的非分散红外吸收系统,往气室内通入不同浓度的多组分气体（含有乙醇、二氧化碳和水蒸气）,采用红外光谱仪进行光谱数据采集,得到多组分气体混合光谱图。根据数据集样本求解回归系数,建立了多元线性回归模型,并进行干扰修正以降低二氧化碳和水蒸气对乙醇浓度预测的影响。对建立的多元线性回归模型进行评价,结果表明:模型真实有效且具有良好的线性回归效果,可以用于预测气体浓度,乙醇、二氧化碳和水蒸气浓度预测误差均在可接受的范围之内,其中乙醇浓度预测误差最小,不超过2.0×10-4。通过干扰修正尽可能排除二氧化碳和水蒸气的干扰,能够较准确地预测乙醇浓度。     

基于MSP430和CC2530的温室大棚数据采集系统设计

设计基于MSP430F149单片机为主控制单元,CC2530为数据采集单元的温室大棚数据采集系统.CC2530连接温湿度传感器AM2301、二氧化碳传感器TGS4161和光照传感器BH1750,对温室大棚内的温湿度、二氧化碳浓度和光照强度进行采集,并将采集到的数据发送给配有CC2530模块的MSP430F149单片机,由单片机对收到的数据进行分析处理并发给上位机存储显示.给出了系统的整体框图、采集电路和系统软件流程图.实际测试表明,系统能够准确的完成温湿度、二氧化碳浓度和光照强度的采集,功耗较低,具有智能化传感器网络的特点,在智能农业领域有着很好的市场前景和推广价值.     

ARM-Linux嵌入式系统在农业大棚中的应用

温度、湿度和二氧化碳浓度是影响棚栽农作物生长的3大要素。为了实现农业大棚中这3种要素数据的远程实时采集,引入了当前嵌入式应用中较为成熟的ARM9微处理器和Linux嵌入式操作系统技术,采用温度传感器PH100TMPA、湿度传感器HM1500和二氧化碳浓度传感器NAP-21A,设计一种基于TCP/IP协议的嵌入式远程实时数据采集系统方案。从硬件设计和软件实现2方面对该系统进行具体阐述。在实际应用中,该系统运行稳定、可靠。     

基于STC89C52维生环境报警器的设计

本文采用低功耗器件并采用合适的硬件方案设计了一种高铁维生坏境报警器,通过电池供应电能能够方便安装和携带,同时有着较低的功耗.高铁车厢室是乘客休息和工作出行提供休息的一个场所.相对来说,其环境较为封闭,车厢中有着比较集中的人员密度,相应的就使得空气中的废气浓度较高,特别是当车厢环境较差,门窗紧闭时,乘客会受到二氧化碳一定...     

On-Line Acquisition of Pulmonary Gas Exchange Data

This paper describes an automatic system for the minute-to-minute collection of pulmonary gas exchange data which may be used to compute the total minute ventilation, oxygen consumption, carbon dioxide production, and respiratory quotient. The data are available in both analogue and digital format, the latter being suited for immediate digital computer processing.     

On-Line Blood and Respiratory Gas Analysis

Data from a patient receiving ventilatory assistance are processed by computer to calculate pulmonary shunt, dead space/tidal volume ratio, oxygen uptake and delivery, and carbon dioxide elimination and delivery. The computations are based on routines described by Kelman and by Severinghaus, but modified to match limitations of testing imposed by the requirements for ventilatory assistance. Analyses are performed sequentially on arterial and venous blood samples and on respiratory gas samples. The output of the blood gas analyzers is fed on-line to a computer together with other data, such as patient identification, which are manually entered at a keyboard and with thumb-wheel switches. The computer processing begins with determining the concentration of oxygen and carbon dioxide in whole blood and of bicarbonate in plasma. The shunt equation is used to calculate a virtual shunt at therapeutic concentrations of inspired oxygen. Dead space/tidal volume ratios are corrected for mechanical dead space in the respiratory circuit. The analyzed results are returned to the operator within seconds via a video display. Since the data include blood samples from multiple patient sites, a cross-comparison is made by the computer and the operator is informed of unusually large differences in values.     

空调房间室内CO2浓度实验研究

鉴于室内空气品质的要求,建立室内CO2浓度对比实验,分析造成夏季空调房间室内CO2浓度累积的影响因素,并分析消除室内CO2浓度累积的通风换气量,指出较小的室内人员密度和良好的通风换气是提高室内空气品质的有效保证。     

计算流体力学在室内空气质量评价中的应用

选择CO2作为学生宿舍内空气质量的评价因子,一方面采用计算流体力学(CFD)数值模拟关窗工况下宿舍内CO2的浓度分布,另一方面实验测定该工况下宿舍内若干点的CO2浓度,并根据实测数据修正CFD数值模拟中的各类参数。在此基础上,进一步数值模拟通风状况下宿舍内CO2的浓度分布及流动状况,并对其室内空气质量进行评价。     

基于VAR模型的PM2.5与其它空气污染物的动态关系研究分析

通过建立向量自回归（VAR）模型,综合运用格兰杰因果关系检验、广义脉冲响应函数和方差分解法,分析PM2.5与其它空气污染物的动态关系,探讨其它空气污染物对PM2.5的影响,利用西安市2013年1月1日-2014年12月31日有关环境空气质量的数据进行了研究。结果表明：PM2.5与其它空气污染物所构成的空气质量系统是稳定的,二氧化硫、二氧化氮、一氧化碳浓度值的增加会引起PM2.5浓度值持续较长时间的增加,其中二氧化硫对PM2.5影响作用最大;臭氧浓度值的增加则会使PM2.5浓度值降低。     

汽车尾气分析仪设计

随着汽车数量的不断增多,汽车尾气己成为空气污染的重要来源。文中设计了一种汽车尾气分析仪系统,实现了对汽车尾气中CO、HC、CO₂、O₂和NO含量的检测。设计采用部分信号调理电路,并应用Pspice电路仿真软件进行了电路仿真,仿真结果显示了调理电路的放大、滤波效果。能根据国家标准对相关参数进行处理,实现了各项测量数据的显示、判断、存档、查询、统计、标定等功能。     

基于STM32的便携式二氧化碳监测仪设计

针对二氧化碳地质储存地区环境中CO2浓度监测,基于STM32F103RE微控制器,设计了一款便携式二氧化碳监测仪,在RS232协议下,实现微控制器与传感器、液晶显示模块、U盘存储模块的数据通讯,系统中选用三个红外吸收型二氧化碳传感器,由继电器控制电路切换三个通道,实现分档采集数据,最后利用监测仪进行了室内CO2气体浓度测试实验,实验结果证明三个数据采集通道工作正常。     

陶瓷封装腔体内气体含量分析与控制

气密性封装技术应用广泛,内部水汽的含量能很好地控制在5 000×10-6以下。但在气密性封装器件的失效分析中发现,失效器件的某些失效与其内部除水汽之外的其他气氛含量异常有关,如锡基焊料焊接芯片长期贮存后抗剪/抗拉强度下降,与内部氧气含量高有关;银玻璃烧结的,长期贮存后抗剪/抗拉强度下降,与内部二氧化碳含量异常相关;内部...     

Transients in Carbon Dioxide Stores

Physiologically correct models of the respiratory control system require accurate knowledge of the structure and dynamics of carbon dioxide stores of the body. Several models of these stores have been investigated and the computed results compared to experiment. The effect on these models of alterations in cardiac output, regional perfusion, and tissue absorptive capacity for carbon dioxide has been examined. Experimental results are best duplicated by a five venous compartment model of carbon dioxide stores with a low absorptive capacity for carbon dioxide during the first few minutes following a change in ventilation.     

柔性有机发光器件封装材料气体渗透率的质谱法测量

柔性有机电致发光器件(FOLED)封装材料的研究已成为目前国内外FOLED研究的热点。如何测量水蒸汽、氧气和其他活性气体对FOLED封装材料的渗透率, 是FOLED封装材料研究的一个重要课题。提出用质谱分析技术解决柔性有机电致发光器件封装材料气体渗透率的测量问题, 建立了一个封装材料渗透率的质谱法测量系统。介绍了该系统的原理, 利用该系统测量了水蒸汽、氧气和二氧化碳等气体对PET塑料, 以及水蒸汽对ITO薄膜、银薄膜等材料的渗透率。所获得的实验结果与其他文献报道的数据进行了比较, 证明质谱法测量的结果是可信的。     

载人深潜器舱室微量有害气体净化技术发展状况

目前的载人深潜器大多只注重保证潜航员的正常呼吸(即保证一定的氧分压,以及控制低浓度二氧化碳),对潜航员在海底舱内工作环境的其他微量有害气体考虑很少。而舱内有害气体净化技术是确保舱内空气质量的重要环节。由于航天舱、潜艇舱与载人深潜器舱室的环境有许多相似点,对目前航天舱以及潜艇舱内的微量有害气体净化技术进行简要介绍与总结。重点介绍了吸附技术、催化燃烧净化技术以及光催化净化技术,为以后发展深潜器长期的海底工作站提供部分借鉴。     

Noninvasive Transcutaneous Monitoring of Arterial Blood Gases

Valuable clinical and physiological data concerning the function of the cardiopulmonary system can be obtained from continuous monitoring of hemoglobin oxygen saturation (SaO2), oxygen tension (PO2), and carbon dioxide tension (PCO2) in blood. While periodic blood sampling is still used clinically to determine arterial blood gases, it is becoming apparent that the recent introduction of continuous noninvasive monitoring of blood gases can offer many advantages. This paper discusses the historical development and significant accomplishments of various techniques available for transcutaneous blood gas monitoring. Four major areas are reviewed: electrochemistry, spectrophotometry, mass spectrometry, and gas chromatography. For each of these techniques, the theoretical basis, instrumentation, and clinical applications are discussed.     

光子晶体光纤CO2气体传感器的研究

为了能高灵敏度地检测CO₂气体的体积分数,基于红外光谱吸收原理,设计了一种以9m长的空芯光子晶体光纤作为传感单元的CO₂气体传感器。利用该传感器测量了不同体积分数的CO₂在同一吸收波长下的吸收光谱图。结果表明,气体的吸收光强和气体的体积分数之间呈线性变化,与比尔-朗伯定律一致;传感器的灵敏度可达4.389×10-5W。可通过加长光子晶体光纤的长度,来增加气体吸收的有效距离,使传感系统获得较高灵敏度。