无创通气不同呼吸界面对COPD患者的生理学影响

目的 探讨无创正压通气(NPPV)时不同呼吸界面对慢性阻塞性肺疾病(COPD)急性加重期并呼吸衰竭患者的生理学影响.方法 选择30例COPD急性加重期并呼吸衰竭患者.无创正压通气时患者随机先后接受不同呼吸界面(面罩、鼻罩和鼻塞).动态观察不同呼吸界面时患者呼吸方式、血气分析和对呼吸界面耐受性等的差异.结果 (1)与自主呼吸相比,无创正压通气时三种不同呼吸界面均可改善患者的潮气量、分钟通气量和呼吸频率(P＜0.01),三种不同呼吸界面时的呼吸频率相似(P＞0.05),但面罩时的潮气量和分钟通气量比鼻罩时更高(P＜0.05);(2)与自主呼吸相比,无创正压通气时三种不同呼吸界面均可改善患者的动脉血气(P＜0.05),面罩和鼻塞时的PCO2比鼻罩时更低(P＜0.05);(3)患者均可耐受三种不同的呼吸界面,但患者对鼻罩的耐受性比面罩和鼻塞更好(P＜0.01).结论 本生理学研究证实了无创正压通气可改善COPD急性加重期并呼吸衰竭患者的呼吸方式和动脉血气,面罩和鼻塞时的疗效更佳,而鼻罩时的耐受性更好.     

The influence of support conditions in the loading fixture on failure mechanisms in the push-out test: a finite element study

The usefulness of the push-out test as an indicator of interface strength was evaluated using finite element models of intact and partially failed cylindrical push-out specimens loaded against a rigid annular support. The irregular stress distributions that were found in intact specimens depended more on interface conditions at the loading fixture than on a 35% increase in interface area. The maximum stress at the interface was a tensile stress. Critical energy release rates for interface failure were calculated for flawed specimens in which flaw size was either 10 or 100 microns, and for boundary conditions at the loading fixture that were either fixed or slipping in the radial direction. The critical energy release rates depended heavily on the support boundary conditions. Thus, the results of parametric push-out tests can be reasonably compared only for specimens that are very similar in geometry and that are loaded in very carefully controlled fixtures.     

DICOM医学图像数据接口的Java实现

DICOM3.0标准作为目前通用的医学图像标准 ,最重要的特性之一在于其面向对象性。本研究依据这一重要特性 ,描述了如何使用面向对象的Java语言实现该标准的接口软件。从而解决了DICOM硬件设备与后继PACS处理软件的接口问题。同时 ,为了克服现有PACS系统的硬件瓶颈 ,对数据读入方式采取了优化 ,大大降低了CPU运行时间和内存占用空间 ,提高了系统的运行质量和性能。     

经络综合导引治疗仪的研制

经络综合导引治疗仪是根据祖国医学的经络学说和养气功理论，应用呼气启动导引，视觉模型提示和穴位电刺激的多因素共同作用，导引气血沿经络运行。主要用于强化瘫痪肢体的康复。该治疗仪以单片微机为程控中心，通过硬件设计和软件开发，实现了呼气触发，视觉提示和位电刺激同步发，１６和电极依次选通和数字化幅度调节等多种功能。     

脚压测量用传感器

本文讨论了用于脚压测量的四类压力传感器，电阻式传感器、压电式传感器，光电式传感器，电容式传感器介绍了其结构、原理和特点，并分析了几种典型的测量接口电路。     

The role of fluid hydrostatic pressure in bone-implant interface load transfer

Permeability of the soft tissue-bone system surrounding artificial joints fixed in cancellous bone was measured in four adult dogs after implants had been in place 2 months. Fluid was forced through a cavity formed by removal of the implant, the cavity was capped with a stopper to allow for pressure generation. Surface permeability of the 2-month-old implant cavity was 45 times less than the permeability of freshly drilled holes in cancellous bone. A mathematical model of a rigid implant resting on a biphasic solid-fluid layer showed the fluid carried 90% of the load when the implant cavity permeability was assumed, but only 27% when the freshly drilled permeability was used. The results suggest caution in interpreting finite-element models with bonded interfaces and suggest a possible role of the fluid in biological response at the interface.     

羟基磷灰石与骨界面抗张强度测试及扫描电镜观察

本文测试了孔隙率为１４％，孔径小于２μｍ的纯羟基磷灰石（ＨＡ）与兔胫骨皮质骨之间界面的抗张强度，２周时为０．７２ＭＰａ；４、８、１６周之间强度无明显差异平均为１．５ＭＰａ。扫描电镜观察表明，２周时拉伸断裂位于ＨＡ－骨界面，４周以后多在ＨＡ晶体颗粒之间。ＨＡ与骨生物适应性好，矿化组织可以直接沉着于ＨＡ表面或ＨＡ内部，近界面处的ＨＡ发生了一定的生物降解反应，且骨矿化与ＨＡ的降解可能达到某种平衡。     

Evaluation of antidecubitus mattresses

Pressure sores are a current problem in hospitals and care of the elderly, leading to protracted hospital stays and a high care burden. The trauma for the patients is severe, and the cost of pressure sore prevention and treatment, is considerable. Antidecubitus mattresses are used for prevention and in treatment, but they also contribute to the cost of treating pressure sores. The problem highlighted in the review is that the mattresses' effectiveness in preventing and treating pressure sores has not been sufficiently evaluated. When antidecubitus mattresses are evaluated, it is often only with regard to aspects of the interface pressure and the mattresses' ability to redistribute the pressure. The review points out the important observation that, to be able to evaluate the efficacy of the antidecubitus mattress, the mattress's effect on tissue viability needs to be studied. The parameters that ought to be considered when evaluating a support surface are: interface pressure, pressure and blood flow distribution, temperature and humidity in the skin-support surface interface. The authors propose that the effect on tissue viability of external loading can be assessed by simultaneous measurement of the interface pressure and tissue perfusion.     

A method for simultaneous recording of electrical activities and spectrophotometric signals from brain slice preparations in vitro

Organ spectrophotometry has been applied to analyze cytochrome redox changes in brain slice preparations. An interface-chamber method for maintaining metabolism of brain slice tissues was devised to reduce noise on recording traces of spectrophotometric signals, and then used for continuous monitoring and simultaneous recording of electrical and optical signals from brain slices. With this method, the noise level during the recording of redox states of cytochromes was decreased to 0.0004 A unit.