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排序方式: 共有9308条查询结果,搜索用时 31 毫秒
31.
Didier Chatel Laurent Delamare Patrick Dang Daniel Lebouvier Franqois Trocherie 《Artificial organs》1997,21(10):1098-1104
Abstract: For original ovoid shaped artificial ventricles. a biomechanical double sac consisting of a biological sac (porcine pericardium) as the blood contact interface and a synthetic sac (Pebax 3533) as the mechanical support to assume systolic-diastolic dynamic constraints was conceived. The volumetric and mechanical properties were assessed with a three-dimensional modeling of Pebax sacs and computerized simulations of their systolic distortions for both right and left ventricular configurations. The stresses and strains of these sacs were represented as quantitative mappings for a maximum end-systolic state and were below the respective threshold values above which the Pebax material is jeopardized for permanent structure impairment. After fatigue tests applied on Pebax strips under the alleged working conditions of Pebax sacs, the material structure was unchanged and maintained its intrinsic mechanical properties. The theoretical maximum stroke volumes were 74.4 cm3 and 62.4 cm for the left and right ventricular configurations, respectively. With these mechanical and volumetric features, the biomechanical double sac concept was considered valid and could be provided for a consequent specific total artificial heart. 相似文献
32.
71例初产妇前置胎盘与人工流产相关性分析 总被引:1,自引:0,他引:1
目的:探讨初孕人工流产与再孕后前置胎盘发生率的相关性。方法:对1992年1月~2001年12月住院分娩的4046例初孕人工流产进行回顾分析,对影响前置胎盘发生率的因素进行x~2检验。结果:初产妇前置胎盘发生率为1.75%;人工流产次数越多,末次人工流产术后至本次妊娠时间间隔越短;人工流产术后有生殖道感染史者,前置胎盘发生率明显增高。结论:人工流产术是前置胎盘的高危因素,应加强育龄妇女的生殖健康宣传和教育,做到有计划受孕,减少非意愿妊娠的发生。 相似文献
33.
不同类型高危儿早期干预的临床研究 总被引:4,自引:0,他引:4
目的 探索早期干预对窒息、高胆、早产三类高危儿智力发育改善的效果,寻找更合适的早期干预措施。方法 将三类高危儿分为干预组及对照组,同时随机选取正常对照组进行随访。干预组采用鲍秀兰教授“0~3岁”早期干预方案训练,各组均在6个月、1岁时分别采用婴幼儿智能发育量表(CDCC)进行智力发育测评,结果用MDI、PDI表示。结果 (1)6个月龄时MDI各干预组与对照组间有显著性差异,窒息组、早产组与正常组间亦有显著性差异;高胆组与正常组间无差异;PDI窒息组中干预组与对照组之间有显著差异(P<0.01),高胆组、早产组均无差异(P>0.05)。(2)1岁时MDI和PDI结果一致,干预组与对照组间比较窒息组、高胆组有显著差异,早产组无差异;窒息组、高胆组干预组与正常组比较无差异,对照组和早产组与正常组比较均有显著差异(P<0.01)。(3)所有干预组测评分值均高于对照组,6个月与1岁之间比较有显著差异,各观察组间比较有显著性差异(P<0.01)。结论 三类高危儿早期干预效果差异较大,干预组均较对照组分值高,早期干预有改善智力发育的作用;三类高危儿中,窒息组、高胆组效果最好,均达到或超过正常水平。所有未干预组均不及正常水平;早期干预对足月高危儿效果显著,对早产儿欠佳,远期效果尚需进一步随访观察。 相似文献
34.
目的 :观察不同部位静脉注射对无痛人工流产术的影响。方法 :随机将 2 0 0例要求行无痛人工流产术的患者分成二组 ,一组静脉注射部位为手背静脉组 ,另一组静脉注射部位为肘部浅静脉 (贵要静脉或肘正中静脉 )组 ,观察静脉推注异丙酚时患者的注射部位有无疼痛症状。结果 :肘部浅静脉注射部位疼痛感明显轻于手背静脉 ,肘部浅静脉注射部位的麻醉起效时间快于手背静脉 ,两组差异有显著性 (P <0 0 5 )。结论 :选择肘部浅静脉注射异丙酚可减轻患者注射部位的疼痛 ,可在短时间内取得理想的麻醉效果。 相似文献
35.
Louise Rose MN Adult Ed Cert BN ICU Cert Dip Nurs Marie F. Gerdtz RN BN AE Cert GDAET PhD 《Australasian emergency nursing journal : AENJ》2007,10(1):26-29
The use of mechanical ventilation in the Emergency Department requires adequate resources in order to maintain patient safety and avoid potential risks. Moreover, developments in technology require increased knowledge of mechanical ventilation techniques to address the complexity of decision-making involved. Organisational issues and system factors have the potential to negatively impact on the ability of the emergency service to provide optimum care to patients receiving mechanical ventilation. These issues include staffing and skill-mix, demand on emergency services, role-delineation, scope of practice, and current mechanisms for monitoring of quality and safety. Furthermore, in response to advances in ventilator technology, current education programs for both nursing and medical staff require review to ensure that they provide comprehensive information about the types of ventilation techniques now available and the relative risks and benefits associated with their application.This article is the second in a two-part series and explores the educational and organisational factors that impact upon safety and quality of care delivered to patients receiving mechanical ventilation in the emergency department. Recommendations for future policy development, curriculum review and reporting mechanisms to support further research in the application of mechanical ventilation in the emergency department are made. 相似文献
36.
37.
骨水泥型人工股骨头假体治疗高龄股骨颈骨折 总被引:5,自引:1,他引:4
目的报告骨水泥型人工股骨头假体治疗高龄股骨颈骨折的疗效。方法131例患者(新鲜骨折101例,陈旧性骨折30例按Garden分型:Ⅱ型23例,Ⅲ型62例,Ⅳ型46例),取后外侧切口安置骨水泥型人工股骨头,术后药物预防静脉血栓。结果随访0.5~8年,优良率96.4%。结论骨水泥型人工股骨头假体置换术具有手术简单,术后恢复快等优点,适用于高龄股骨颈骨折患者。 相似文献
38.
Cora Rotary Pump for Implantable Left Ventricular Assist Device: Biomaterial Aspects 总被引:3,自引:0,他引:3
Abstract: Our group is developing a left ventricular assist device based on the principle of the Maillard-Wankel rotative compressor: it is a rotary, not centrifugal, pump that produces a pulsatile flow. Stringent requirements have been defined for construction materials. They must be light, yet sufficiently hard and rigid, and able to be machined with high precision. The friction coefficient must be low and the wear resistance high. The materials must be chemically inert and not deformable. Also, the materials must be biocompatible, and the blood contacting surface must be hemocompatible. We assessed the materials in terms of physiochemistry, mechanics, and tribology to select the best for hemocompatibility (determined by studies of protein adsorption: platelet, leukocyte, and red cell retention: and hemolysis, among other measurements) and biocompatibility (determined by measurement of complement activation and toxicity, among other criteria). Of the materials tested, for short- and middle-term assistance, we chose titanium alloy (Ti6 AI4 V) and alumina ceramic (Al2 O3 ) and for long-term and permanent use, composite materials (TiN coating on graphite). We saw that the polishing process of the substrate must be improved. For the future, the best coating material would be diamond-like carbon (DLC) or crystalline diamond coating. 相似文献
39.
J. P. Clarke 《Intensive care medicine》1997,23(1):106-109
Objective: To determine the effects of pressure control inverse ratio ventilation [PC-IRV], as compared with volume controlled normal
ratio ventilation [VC], on the intracranial pressure [ICP] of patients with severe head injury.
Design: A prospective study with unblinded intervention.
Setting: The Intensive Therapy Unit of a base hospital.
Patients and participants: Nine cases of head injury requiring mechanical ventilation and intracranial pressure monitoring were studied.
Interventions: Patients were twice transferred from VC (I:E ratio 1:2) to PC-IRV (I:E ratio 2:1). Firstly, tidal volume was maintained
at an equal value. Secondly, end tidal CO2 was maintained at an equal value. No other changes were made to ventilation, vasopressor therapy or ICP control.
Measurements and results: Measurements were taken of ICP, mean arterial pressure (MAP) end tidal CO2 and respiratory parameters. In the first observation, there were significant changes in peak inspiratory pressure (PIP),
mean airway pressure (Paw) and intrinsic positive end expiratory pressure (PEEP) but not for ICP, end tidal CO2, MAP and cerebral perfusion pressure (CPP). The correlation between change in ICP and change in end tidal CO2 was r=–0.74. In the second observation there were significant changes in tidal volume, PIP, Paw and intrinsic PEEP but not for
ICP, MAP and CPP. The correlation between the change in ICP and the change in Paw was insignificant.
Conclusions: PC-IRV has a minimal net effect on ICP. Changes in ICP correlate more strongly with changes in CO2 than changes in Paw.
Received: 16 January 1996 Accepted: 2 September 1996 相似文献
40.
F. BRUNET J. P. MIRA C. CERF M. BELGHITH O. SOUBRANE J. L. TERMIGNON† B. RENAUD L. FIEROBE I. HAMY M. MONCHI E. DESLANDE A. BRUSSET† J. F. DHAINAUT 《Artificial organs》1994,18(11):826-832
Abstract: This open clinical study was aimed at testing the hypothesis that an intravascular oxygenator (IVOX) may help to perform permissive hypoventilation in 10 patients with severe ARDS. After initial evaluation, we tried to reduce ventilator settings before and after IVOX implantation. Before IVOX, poor clinical tolerance and worsening oxygenation did not allow for a significant decrease in ventilator settings. With IVOX, peak inspiratory pressure (PIP) was reduced from 47 to 39 cm H2 O (p = 0. 005) and minute ventilation from 13 ± 3. 5 to 11 ± 3 L/min. CO2 removal by IVOX allowed a significant decrease in Paco2 from 66 ± 15 to 59 ± 13 mm Hg. Improvement of oxygenation with IVOX was not signify cant. Furthermore, interruption of oxygen flow through IVOX did not change oxygenation variables. Tolerance of the IVOX device was good, but insertion of the device was followed by a significant decrease in both cardiac index and pulmonary wedge pressure. In conclusion, IVOX improves tolerance of hypoventilation by limiting hypercapnia in ARDS patients. These preliminary results must be confirmed by a randomized controlled study 相似文献