体位变化所致脉压波动为指导的干预措施对剖宫产腰硬联合麻醉产妇母婴状态的影响

目的观察与比较体位变化所致脉压波动为指导的干预措施对剖宫产腰硬联合麻醉产妇母婴状态的影响。方法选取2018年1月-2019年2月在医院行剖宫产腰硬联合麻醉产妇180例为研究对象,依据随机数字表法分为对照组(常规干预组) 90例和观察组(体位变化所致脉压波动为指导的干预措施组) 90例,比较两组产妇麻醉前、后不同时间的血压、心率、低血压、低血氧饱和度及心率过缓发生率、新生儿1 min及5 min Apgar评分、不良反应发生率(恶心及呕吐)。结果观察组产妇麻醉后不同时间的血压、心率均高于对照组产妇,低血压及心率过缓发生率、不良反应(恶心及呕吐)发生率显著低于对照组产妇,差异均有统计学意义(P<0. 05),两组的新生儿1 min及5 min Apgar评分比较差异无统计学意义(P>0. 05)。结论体位变化所致脉压波动为指导的干预措施对剖宫产腰硬联合麻醉产妇状态的影响相对更好,且对新生儿未见不良影响,因此在本类产妇中具有较高的应用价值。

老年高血压患者玻璃体切除术中脉压波动

目的研究老年高血压患者玻璃体切除术中脉压(PP)波动的变化情况。方法选择2012年6月至2014年6月收治的60例需行玻璃体切除术的老年高血压患者,根据高血压病史和年龄将其随机分为老年高血压组(实验组,30例,30只眼)和老年正常血压组(对照组,30例,30只眼)。测量患者入院时(PP1)、玻璃体切除术术前结膜切口时(PP2)、切除玻璃体开始时(PP3)、玻璃体切除手术结束时(PP4)各时间点的脉压值,观察记录术前和术后所有患者视力及眼压变化,并确保患者的安全及手术顺利进行。结果所有患者均顺利成功完成手术,术中无特殊情况发生,术后所有患者视力均有提高(P<0.01),患者术后恢复情况良好,患者手术前后眼压均在正常范围,差异未见统计学意义(P>0.05)。结论玻璃体切除手术可以有效控制老年人的眼部疾病恶化,使老年患者的视力得到有效的改善,同时在手术切除过程中及术后,医护人员需要密切关注患者的各项生理指标,加强手术关注力度,从而确保手术的顺利进行及患者的术后康复。

亲子互动影像包在幼儿麻醉诱导护理中的应用

[目的]观察亲子互动影像包在幼儿麻醉诱导护理中的应用效果。[方法]将86例行手术治疗的幼儿随机分为观察组、对照组各43例,对照组幼儿接受常规麻醉诱导护理,观察组在此基础上加用亲子互动影像包护理工具,对两组干预后焦虑评分、麻醉配合度评分以及心率、平均动脉压波动值进行比较。[结果]观察组幼儿干预后焦虑评分、麻醉配合度评分以及心率、平均动脉压波动值显著低于对照组(P<0.05)。[结论]在幼儿麻醉诱导护理中加用亲子互动影像包工具可显著改善手术幼儿的焦虑情绪,提升其麻醉配合度,降低应激反应。

Multi-target range and velocity measurements of a digital phased array radar system

As the core of a digital phased array radar system,a radar signal processing environment is created to measure multitarget range and velocity information. The radar echo signal is achieved by superposing target echo, noise, clutter and jamming signals linearly. Considering that these signals have many types,two typical combinations are selected to construct the multi-target echo signal and the simulated echo signal is used as the input of the signal processing environment. This environment mainly adopts pulse compression,moving target indication and detection technologies to process the echo signal.It is found that the frequency domain method is more desirable for the pulse compression effect than the time domain method,and multi-target range information can be measured from the moving target indication result after using a double delay canceller. A new moving target detecting method is proposed,which can present the positive and negative velocity accurately with the multi-target range and velocity measured simultaneously. Simulation results indicate that the potential targets are detected from the chaotic radar echo signals successfully,and their range and velocity can be figured out correctly in the built radar signal processing environment.

Analysis and numerical simulation of dynamic effect on rock under high pressure water jet

Based on continuum mechanics and rock dynamics,analyzed the micro-struc- ture damage of rock and the impulsive effect under high pressure water jet and developed the dynamic model.Further,on the assumption of that rock was homogeneous and iso- tropic,a computational model was established based on nonlinear finite element and Arbi- trary Lagrangian-Eulerian(ALE) method.The dynamic effect impacted on rock under high pressure water jet was simulated by the dynamic contact method.The propagation of stress wave in rock was numerically simulated at different impacting velocity.The results show that the propagation velocity of stress wave is proportional to the impacting velocity of high pressure water jet.The faster the impacting velocity is,the quicker the comedown of stress wave.

调控中心静脉压对肺心病治疗的探讨

目的 探讨在肺心病患者治疗中,控制中心静脉压对患者预后的影响。方法 选取失代偿期的肺心病患者180例,随机分为治疗组、对照组;对照组、治疗组各90例。对照组按照常规疗法进行治疗,中心静脉压波动在10-18cmH2O;治疗组在常规治疗的基础上,调控中心静脉脉压,创新点是：调控中心静脉脉压波动2-7cmH2O,通过利尿、扩血管等措施。记录各病例治疗过程中心功能改善状况、治疗中机械通气应用的时是。结果调控中心静脉压治疗组心功能改善好,个病例中辅助通气时间少（P〈0.05）。结论 调控中心静脉压治疗方法对肺心病患者的治疗效果好于传统疗法。

Prediction of pulmonary arterial wedge pressure from arterial pressure or pulse oximetry plethysmographic waveform

Objective To assess the possibility of using arterial pressure waveform or pulse oximetry plethysmographic waveform variation to estimate the pulmonary arterial wedge pressure (PAWP) Methods Fourteen American Society of Anesthesiologists grade Ⅰ-Ⅱ patients aged 33-69 years and weighing 62 0±9 5 kg scheduled for elective abdominal tumor surgery were studied Their hemoglobin exceeded 120 g/L and hematocrit exceeded 35% Pre operative acute hypervolemic hemodilution was applied immediately after general anesthestic induction and tracheal intubation PAWP, systolic pressure variation (SPV), delta down (dDown), SPV plet , dDown plet and other hemodynamic parameters were measured and recorded when total fluid volume (crystalloid and colloid) infused reached 10 ml/kg and 20 ml/kg and again at the end of the operation Central venous pressure was maintained at 10-12 mm Hg during operation Systolic blood pressure at the end of Valsalva maneuver (airway pressure was kept at 22 mm Hg) and the systolic pressure before the Valsalva manoeuvre during apnea were used to calculate arterial pressure ratio (APR) Results APR, SPV, dDown, SPV plet and dDown plet all correlated well with PAWP ( r =0 717, -0 695, -0 680, -0 522 and -0 624 respectively, P <0 01) There was a closer linear correlation between APR and PAWP than between the other parameters The regression equation was PAWP (mm Hg)=0 207×APR (%)-0 382 Conclusion During positive pressure mechanical ventilation, APR, SPV, dDown, SPV plet and dDown plet can be used to estimate PAWP effectively

Pressure fluctuation propagation of a pump turbine at pump mode under low head condition

Pressure fluctuation at the vaneless space and vanes passages is one of the most important problems for the stable operation of a pump turbine. The fluctuation appears in any operating condition. Much research has been done on the pressure fluctuation of hydraulic machinery. However, the details of pressure fluctuation propagation of the pump turbine at the pump mode have not been revealed. The modem pump turbine with high water head requires the runner to be ＂flat＂, which would induce pressure fluctuation more easily than the low head pump turbine. In this article, a high head pump turbine model is used as the re- search object. As the pressure fluctuation at off-design point is more serious than at the design point, the low head condition is chosen as the research condition. Pressure fluctuation at the vaneless space and vanes passages is predicted by the computa- tional fluid dynamics method based on k-co shear stress transport model. The experiment conducted on the test rig of the Har- bin Institute of Large Electrical Machinery is used to verify the simulation method. It proves that the numerical method is a feasible way to research the fluctuation under this operating condition. The pressure fluctuation along the passage direction is analyzed at time and frequency domains. It is affected mainly by the interaction between the runner and vanes. In the circumferential direction, the influence of the special stay vane on the pressure fluctuation is got. The amplitude in the high-pressure side passage of that vane is lower than that in the other side. The study provides a basic understanding of the pressure fluctua- tion of a pump turbine and could be used as a reference to improve the operation stability of it.

External iliac artery injury secondary to indirect pressure wave effect from gunshot wound

In patients presenting with gunshot wounds, a high clinical suspicion of injury to vasculature and viscera remote from the projectile track is paramount. We present a case of a 17 year old male who sustained a gunshot wound to his abdomen and subsequently developed a right external iliac artery contusion recluiring surgery as an indirect effect of the oressure wave from the bullet.

Determination of delay time in individual transfer function for central aortic pressure reconstruction

In previous research, time-delay （△t） was a more important parameter than the reflection coefficient in the individual transfer function of central aortic pressure reconstruction. The At can be obtained by electrocardiography （ECG） or phonocardiography （PCG）. Because the pre-ejection period remains an uncertain factor, the present study used ECG and PCG to define the delay time and analyzed the accuracy of the reconstruction results. The △tpre is the actual delay time derived from the aorta to the carotid pressure wave, △tpco is the time delay between the aortic valve component of the second heart sound and the dicrotic incisura of the carotid pressure wave, and AtEcc represents the delay from the interval of the ECG R-peak to the foot of the carotid pressure wave. Compared with the measured aortic pressure, the reconstruction result obtained by △t=△tpcslightly differed from the best result estimated by △t=△tpre. However, the differences between the result obtained by △t=△tEco and the best result were significant in terms of the diastolic blood pressure, and pulse pressure, and especially in terms of the augmentation index and root-mean-square-error. Thus, the At should be determined by PCG for central aortic pressure reconstruction in practice.

Effect of Exit Geometry of Tail Pipe on the Performance of Pulse Jet Engines

In this paper,the effect of geometries of tube open end on the shock,compression and expansion wavespropagating in the tube was investigated numerically and experimentally.One of them is a conventional straightshock tube with an open end.The other has a divergent tail tube at the exit.Applying a divergent tail tube(flaretube)to an open end shock tube,the period of one-cycle process could be shortened and the pressure behind theexpansion wave produced at the exit of the shock tube could be lowered much more below the atmosphericpressure than that produced in the straight tube.The results suggested that the intake air into the engine wassignificantly increased by applying a flare tube instead of a straight tube.