Multiple Respiratory Gas Monitoring Causes Changes of Inspired oxygen Concentration in Closed Anesthesia System

Effect of multiple respiratory gas monitoring (MRGM ) on inspiredconcentration of oxygen in circult system during closed anesthesia was studied in 5l adult patients scheduled for abdominal surgery. Required flow rate of fresh oxygen (OFR), inspired oxygen concentration (FiO2 ) and oxygen saturation of pulse oximeter (SpO2) were measured continu0usly. Patients were equally divided into three groups at randorn, group C (no MRGN used ), group M, (using MRGM with its tail gas returned to circuit system), group M2 (using MRGM without tail gas returned ). The results revealed that during 180 min of closed anesthesia, OFR required in group C and M, were about 200-230 ml/min, and in group M, it was ab0ut 400 ml/min. In group C FiO2 decreased by about 10 % after 60 min of closed anesthesia (P<0. 01, 60 min vs 0 min ) and then stayed stable at this level. In group M,, FiO2 decreased by 16% at 60 min and 34 % at 180 min and the decrease was significantly greater than that in gr0up C (P<0. 01). In group Me, FiO2 remained c0nstant during closed anesthesia, which was much high(Jr than those in group C and M,. The tail gas of Capnomac Ultima MRGM contained less oxygen than its sample gas drawn fr0m circuit system simuItaneously.

Closed Anesthesia with Nitrous Oxide

Anesthesia was induced with intravenous thiopental, fentanyl, and succinylcholine, and maintained with isoflurane, N2O-O2 and atracurium after denitrogenation in 20 adult patients. Inspired and end-tidal concentrations of O2,N2O, CO2, isoflurane and oxygen saturation of pulse oximeter (SpO2) were monitored. After intubation, N2O (750 ml/min) and O2 (250 ml/min) were administrated. When inspired N2O concentration (FiN2O) reached 60% the closed anesthesia was initiated by adjusting fresh gas flow rate in order to meet the oxygen demand of the patients. The N2O/O2 ratio was constantly kept at 0. 7. The results revealed that during wash-in period, FiN2O increased, on average, to 30% at 3. 83 min, 40% at 6. 22 min, 50% at 14. 13 min respectively. After 30 min of closed anesthesia, FiN2O decreased to 49. 4 %. It was 46. 8 % at 60 min. Thereafter it increased smoothly to 51. 9% at 180 min. No hypoxia and hypercapnia occurred. Compared with commonly used high flow N2O-N2 inhalation, the technique of low flow wash-in and closed circuit maintenance with N2O-O2 may be less expensive and feasible and causes less pollution.

Anesthesia Related Closed Claims and Litigations at the Detroit Medical Center: Analysis, Lessons Learned, and Conclusions

The analysis of closed claims and litigations can provide an invaluable tool to improve patient safety by minimizing adverse anesthesia-related outcomes. Analysis of collective data describing such claims is integral to develop new guidelines aimed to reduce adverse anesthesia-related events. In this study, we give a descriptive analysis of anesthesia-related claims at the Detroit Medical Center, Detroit, MI, USA. The study analyzed different components in anesthesia-related closed claims and litigations such as medical, demographic and socio-economic factors. From 67,000 procedures in anesthesiology care provider, related cases claims were made in 0.057% (38/67,000) of all cases. The majority of claims involved procedures involving Caucasian females aged 51-55 years. The highest risk periods involved early shift times during Monday and Tuesday, particularly of procedures performed during August. About 33% of all cases in which death occurred involved patients who received an Obstetrics/Gynecology or an Orthopedic procedure under general anesthesia. The majority of closed claims and litigations cases were distributed between procedures treating nerves injuries and anoxic encephalopathy. The OR and PACU at urban hospitals had the highest claim rates. MD anesthesiologists constituted the lowest proportion of all anesthesia providers involved in closed claims incidents. The average compensation paid was predominately in the range of $200,000-$250,000. In addition to reporting anesthesia related factors involved in closed claims and litigations this study also includes a series of recommendations which may work as a framework for improving anesthesia practices.

Signal averaging for noise reduction in anesthesia monitoring and control with communication channels

This paper investigates impact of noise and signal averaging on patient control in anesthesia applications, especially in networked control system settings such as wireless connected systems, sensor networks, local area networks, or tele-medicine over a wide area network. Such systems involve communication channels which introduce noises due to quantization, channel noises, and have limited communication bandwidth resources. Usually signal averaging can be used effectively in reducing noise effects when remote monitoring and diagnosis are involved. However, when feedback is intended, we show that signal averaging will lose its utility substantially. To explain this phenomenon, we analyze stability margins under signal averaging and derive some optimal strategies for selecting window sizes. A typical case of anesthe-sia depth control problems is used in this development.

Design of Type-1 and Interval Type-2 Fuzzy PID Control for Anesthesia Using Genetic Algorithms

This paper presents the automatic drug administration for the regulation of bispectral (BIS) index in the anesthesia process during the clinical surgery by controlling the concentration target of two drugs, namely, propofol and remifentanil. To realize the automatic drug administration, real clinical data are collected for 42 patients for the construction of patients’ models consisting of pharmacokinetic and pharmacodynamic models describing the dynamics reacting to the input drugs. A nominal anesthesia model is obtained by taking the average of 42 patients’ models for the design of control scheme. Three PID controllers are employed, namely linear PID controller, type-1 (T1) fuzzy PID controller and interval type-2 (IT2) fuzzy PID controller, to regulate the BIS index using the nominal patient’s model. The PID gains and membership functions are obtained using genetic algorithm (GA) by minimizing a cost function measuring the control performance. The best trained PID controllers are tested under different scenarios and compared in terms of control performance. Simulation results show that the IT2 fuzzy PID controller offers the best control strategy regulating the BIS index while the T1 fuzzy PID controller comes the second.

Closed circle DNA algorithm of change positive-weighted Hamilton circuit problem

Chain length of closed circle DNA is equal. The same closed circle DNA＇s position corresponds to different recognition sequence, and the same recognition sequence corresponds to different foreign DNA segment, so closed circle DNA computing model is generalized. For change positive-weighted Hamilton circuit problem, closed circle DNA algorithm is put forward. First, three groups of DNA encoding are encoded for all arcs, and deck groups are designed for all vertices. All possible solutions are composed. Then, the feasible solutions are filtered out by using group detect experiment, and the optimization solutions are obtained by using group insert experiment and electrophoresis experiment. Finally, all optimization solutions are found by using detect experiment. Complexity of algorithm is concluded and validity of DNA algorithm is explained by an example. Three dominances of the closed circle DNA algorithm are analyzed, and characteristics and dominances of group delete experiment are discussed.

Using Automation Controller System and Simulation Program for Testing Closed Circuits of Mini-Sprinkler Irrigation System

The field experiments were conducted at the experimental farm of Faculty of agricultural, southern Illinois University SIUC, USA. The project makes the irrigation automated. With the use of low cost sensors and the simple circuitry makes currently project a low cost product, which can be bought even by a poor farmer. This research work is best suited for places where water is scares and has to be used in limited quantity and this proposal is a model to modernize the agriculture industries at a mass scale with optimum expenditure. In the field of agricultural engineering, use of sensor method of irrigation operation is important and it is well known that closed circuits of Mini-sprinkler irrigation system are very economical and efficient. Closed circuits are considered one of the modifications of Mini-sprinkler irrigation system, and added advantages to Mini-sprinkler irrigation system because it can relieve low operating pressures problem at the end of the lateral lines. In the conventional closed circuits of Mini-sprinkler irrigation system, the farmer has to keep watch on irrigation timetable, which is different for different crops. Using this system, one can save manpower, water to improve production and ultimately profit. The data could be summarized in following: Irrigation methods under study when using lateral length 60 mcould be ranked in the following ascending order according the values of the predicted and measured head losses CM1M-SIS CM2M-SIS.The correlation (Corr.) coefficients were used to compare the predicted and measured head losses along the lateral lines of all the closed circuits designs. Generally, the values of correlation analysis were (>0.90) were obtained with 0% field slope60 mlength (experimental conditions) for all closed circuits.The interaction between irrigation methods: at the start there are significant differences between CM2M-SIS and CM1M-SIS.

Energy and water saving by using modified closed circuits of drip irrigation system

The aim of this research was determine the en- ergy and water use efficiencies under the modification of closed circuit drip irrigation systems designs. Field experiments carried out on transgenic maize (GDH, LL3), (Zea Mays crop) under two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Drip Irrigation System (CM1DIS);b) Closed circuits with Two Manifolds of Drip Irrigation System (CM2DIS), and c) Traditional Drip Irrigation System (TDIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter;30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar under Two levels slope conditions 0% and 2%. Experiments were conducted at the Agric. Res. Fields., Soil and Plant & Agric. System Dept., Agric. Faculty, Southern Illinois University, Car- bondale (SIUC), Illinois, USA. Under 0% level slope when using CM2DIS the increase percent of Energy Use Efficiency (EUE) were 32.27, 33.21, and 34.37% whereas with CM1DIS were 30.84, 28.96, and 27.45% On the other hand when level slope 2% were with CM2DIS 31.57, 33.14, and 34.25 while CM1DIS were 30.15, 28.98, and 27.53 under lateral lengths 40, 60 and 80 m respectively relative to TDIS. Water Use Efficiency (WUE) when level slope 0% under CM2DIS were 1.67, 1.18, and 0.87 kg/m3 compared to 1.65, 1.16, and 0.86 kg/m3 with CM1DIS and 1.35, 1.04, and 0.75 kg/m3 with TDIS whereas with level slope 2% when using CM2DIS were 1.76, 1.29, and 0.84 kg/m3 compared to 1.77, 1.30, and 0.87 kg/m3 with CM1DIS and 1.41, 1.12, and 0.76 kg/m3 (for lateral lengths 40, 60, and 80 meters respectively). Water saving percent varied widely within individual lateral lengths and between circuit types relative to TDIS. Under slope 0% level CM2DIS water saving percent values were 19.26, 12.48, and 14.03%;with CM1DIS they were 18.51, 10.50, and 12.78%;and under slope level 2% with CM2DIS they were 19.93, 13.26, and 10.38% and CM1DIS were 20.49, 13.96, and 13.23% (for lateral lengths 40, 60, 80 meters respectively). The energy use efficiency and water saving were observed under CM2DIS and CM1DIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitters, lateral line uniformity, and friction losses. CM2DIS was more energy use efficiency, EUE, water saving, and WUE than either CM1DIS or TDIS.

Effect of closed circuits drip irrigation system and lateral lines length on growth, yield, quality and water use efficiency of soybean crop

Field experiment was conducted for one growing season (2012) in clay loam soil at the Experimental Farm of Faculty of Agriculture, Southern Illinois University at Carbondale (SIUC), USA on soybean crop to study the effect of: 1) the closed drip irrigation system: closed circuits with one and two a manifolds for lateral lines (CM1DIS;CM2DIS) and traditional drip irrigation system (TDIS) as a control;and 2) lateral lines length (LLL): LLL1, LLL2 and LLL3 (40, 60,80 m) on soybean growth, yield, oil, protein content and water use efficiency. Plants were drip irrigated every 4 days. N, K2O and P2O5 fertilizers were added via irrigation water. Data obtained could be outlined as follows: 1) According to the mean values of soybean crop growth (leaf area;plant height), yield (grain and straw), both oil and protein content and water use efficiency, the treatment used could be ranked in the following ascending orders: TDIS < CM1DIS < CM2DIS and LLL3 < LLL2 < LLL1;2) Differences in the means of the studied data among treatments used were significant at the 1% level;3) The effects of the DIC × LLL on the data obtained were significant at the 1 % level;And 4) the highest values of the obtained data and the lowest ones were achieved in the following interactions: CM2DIS × LLL1;TDIS × LLL3, respectively.

Modification of water application uniformity among closed circuit trickle irrigation systems

The aim of this research was determine the ma- ximum application uniformity of closed circuit trickle irrigation systems designs. Laboratory tests carried out for Two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Trikle Irrigation System (COMTIS);b) Closed circuits with Two Manifolds of Trikle Irrigation System (CTMTIS), and c) Traditional Trikle Irrigation System (TTIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter;30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar. Experiments were conducted at the Agric. Eng. Res. Inst., ARC, MALR, Egypt. With COMTIS the emitter flow rate was 4.07, 3.51, and 3.59 lph compared to 4.18, 3.72, and 3.71 lph with CTMTIS and 3.21, 2.6, and 2.16 lph with TTIS (lateral lengths 40, 60, and 80 meters respectively). Uniformity varied widely within individual lateral lengths and between circuit types. Under CTMTIS uniformity values were 97.74, 95.14, and 92.03 %;with COMTIS they were 95.73, 89.45, and 83.25 %;and with TTIS they were 88.27, 84.73, and 80.53 % (for lateral lengths 40, 60, 80 meters respectively). The greatest uniformity was observed under CTMTIS and COMTIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitter and lateral line. CTMTIS was more uniform than either COMTIS or TTIS. Friction losses were decreased with CTMTIS in the emitter laterals at lengths 40 meters compared to TTIS and COMTIS. Therefore, differences may be related to increased friction losses when using TDIS and COMDIS.

The effect of different inflation volumes of laryngeal mask airway on efficacy of closed circuit controlled ventilation in pediatric cancer patients

Objective： The laryngeal mask airway （LMA） is an established way for airway control during spontaneous ventila- tion. Its ability to deliver positive pressure ventilation without leakage especially in low flow states is still controversy. The aim of this study is to test the possibility of using LMA in pediatric closed circuit controlled ventilation, and to find out the optimum cuff volume to perform closed system ventilation. Methods： Twenty children scheduled for elective surgeries were enrolled in a crossover study. Laryngeal mask airway was used. In stage I, the cuff was inflated with the maximum volume of air as rec- ommended by the manufacturers. Adjustment of volume of air inflated into the LMA cuff to the minimum volume to obtain the effective seal was done at stage II. The leak pressure, intracuff pressure and the leak volume were measured in both stages. Results： The cuff filling volume was significantly lower compared to the maximum cuff inflation volume in stage I. Leakage values showed significantly less values in stage II of the study with smaller cuff inflation volumes. The airway leakage pressure was significantly lower in stage fl in comparison to stage I. Cuff inflation pressure in stage I showed marked elevation which dropped significantly after adjustment of cuff volume in stage I1. Conclusion： Laryngeal mask airway is an effective tool to provide closed circuit controlled ventilation in pediatrics. Inflation of the cuff by the minimum volume of air needed to reach the just sealing pressure is suggested to minimize the leakage volume.

Dynamic modeling and analysis of the closed-circuit grinding-classification process

Mathematical models of the grinding process are the basis of analysis, simulation and control. Most existent models in- cluding theoretical models and identification models are, however, inconvenient for direct analysis. In addition, many models pay much attention to the local details in the closed-circuit grinding process while overlooking the systematic behavior of the process as a whole. From the systematic perspective, the dynamic behavior of the whole closed-circuit grinding-classification process is consid- ered and a first-order transfer function model describing the dynamic relation between the raw material and the product is established. The model proves that the time constant of the closed-circuit process is lager than that of the open-circuit process and reveals how physical parameters affect the process dynamic behavior. These are very helpful to understand, design and control the closed-circuit grinding-classification process.

“电路原理”混合式智慧教学的探索与实践

“电路原理”混合式智慧教学,以学生为中心,在优化设计教学内容、系统建设教学资源的基础上,将智慧教学平台和群聊工具引入课程,构建“课前预习—课堂学习—课后评价及反馈”知识点闭环教学系统,通过线上学习与线下教学混合、课内学习与课外自学混合、群聊工具与课程教学混合、理论学习与工程应用混合,在实现教与学充分融合的同时,促进学生自主学习能力,有效提高课程的教学质量。

永磁同步电机矢量控制专用集成电路的设计

针对软件矢量控制策略因响应慢、成本高而无法满足永磁同步电机(PMSM)领域控制新需求的问题,设计一种矢量控制专用集成电路(ASIC)。采用双闭环控制结构为基础设计芯片架构,使用VerilogHDL硬件描述语言设计矢量控制、坐标旋转数字计算(CORDIC)、电流采样接口、编码器接口和串口通信等模块,通过硬件架构实现并行加速。利用ModelSim平台仿真验证所设计电路的功能,以FPGA为核心搭建芯片物理验证平台,控制PMSM的电流与速度。结果表明:所设计的ASIC输出PWM信号达到12.2 kHz,双环频率分别达到12 kHz和8 kHz,具有快速动态响应与良好的稳态特性;且能够实现高性能、低成本、可移植的电机控制,在电机控制领域具有一定的应用价值。

基于反激变换器的电池充电系统设计

以具有结构简单、电气隔离等优点的反激变换器为电池充电电源,分析反激变换器电路的连续和断续模式工作原理,通过设计电压电流双闭环控制方法,实现电池的恒流充电模式和恒电压充电模式,也可实现两种充电模式的切换。实验结果证明了反激变换器的连续工作模式和断续工作模式的正确性,验证了应用于电池充电电源的可行性和有效性,切换时间小于1 ms,电压波动小于1 V。

基于电机电流的高压断路器弹簧操作机构的LM-BP故障诊断算法

BP(back propagation)神经网络由于具有线性映射能力强及自适应能力强等优点,常被用于高压断路器弹簧操作机构的故障诊断中,但易陷入局部最小点限制了网络的收敛速度和分类精确度。文中提出了一种基于L-M算法优化BP神经网络的高压断路器操作机构故障诊断方法,分析了神经网络的数学模型及映射关系,运用L-M算法对传统BP网络进行优化,解决了传统BP神经网络梯度下降法存在局部最小化、易产生平坦区等问题,有效地提高了算法的训练速度,同时提高了分类的精确度。诊断结果表明:L-M算法优化后的BP神经网络能有效地实现高压断路器操作机构故障诊断。文中研究内容对高压断路器操作机构故障诊断提供了思路与方法,对提高高压断路器安全可靠性具有重要意义。

具备限流能力的混合式高压直流断路器拓扑

直流断路器(DCCB)是解决直流系统短路故障的重要手段,针对现有DCCB存在的限流效果差、避雷器使用寿命短和故障隔离速度慢等一系列缺陷,文中提出一种具备限流能力的混合式高压直流断路器拓扑(CLC-HDCCB)方案。CLC-HDCCB载流支路和转移支路采用双桥式结构,具备双向通断能力;限流部分采用限流电阻和限流电感并联限流方式,显著降低了故障电流峰值及上升率;设计泄能电阻在断路过程中将限流电感旁路,减少了避雷器单次开断吸收的能量;对所提CLC-HDCCB方案分断故障电流、正常合闸和分断小电流等直流系统出现的各种工况进行了详细分析,并给出参数选定的方法。最后在PSCAD/EMTDC平台进行仿真验证,结果表明所提CLC-HDCCB方案与现有DCCB方案相比在故障限流、避雷器吸能和故障清除时间等方面具有一定的优势。

基于动态灰色关联分析法的高压断路器机械故障诊断

高压断路器机械故障成因复杂,机械故障与分合闸线圈电流之间难以找到解析的映射关系。因此引入灰色关联分析法,建立一种高压断路器机械故障诊断模型,进一步通过计算参考数列与比较数列的距离来选择分辨系数,提出一种基于动态分辨系数的灰色关联分析法。该方法不需要大量样本数据,且算法精度不受信号干扰的影响。研究表明,选取铁心卡涩运动的时间参量相关度作为故障诊断特征量能有效诊断出高压断路器机械故障。

断路器碳陶瓷合闸电阻能量耐受及失效特性

合闸电阻在大能量注入下的热电耐受及性能稳定是超/特高压交流系统断路器安全稳定运行的关键因素。为此通过开展合闸电阻模拟能量注入实验,并建立碳陶瓷复合材料微观结构热电耦合仿真模型,研究碳陶瓷电阻在不同强度能量注入下的材料温升、动态导电、性能劣化及结构破坏行为,分析碳陶瓷合闸电阻的能量耐受及失效机理。研究发现,碳陶瓷电阻具有随温度变化的动态导电特性,导通电阻及恢复电阻随能量注入强度的增加而减小;在大能量注入下,碳陶瓷电阻劣化及损伤模式包含恢复电阻下降、侧面绝缘击穿及电阻体碎裂。根据大能量注入下电阻内部多物理场分布仿真结果,结合碳陶瓷复合材料微观结构观察及电接触导电机制分析,揭示来源于碳陶瓷电阻内部电流密度、温度及热应力不均匀分布的性能劣化及结构破坏电热正反馈物理机制。

基于频率控制的封闭腔体微波无线输能技术

随着航空航天技术的快速发展,封闭腔体内的无线能量传输(Wireless Power Transmission,WPT)技术开始受到广泛关注.基于频率控制的WPT技术,可实现对电大封闭腔体(103×λ3)内的多方位传感器进行可控和高效的无线充电.电大腔体内的电场分布对频率的变化敏感,利用频率变化实现对封闭腔体场分布控制.实验结果表明,在S波段的1 m3腔体最高WPT传输效率为96.6%.设计的宽带整流电路实测整流效率最高为80%,整流效率高于50%的带宽为1.65 GHz.在2.401~2.495 GHz频段实现控制双接收机的不同工作状态,展现其在航空航天器等封闭空间中为传感器无线供电的应用前景.