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find Keyword "血流动力学" 96 results
  • 局部应用噻吗心安对人眼脉络膜血液循环的影响

    The effcet of topical timolol maleate 0.5% on the coroidal circulation was investigaed in 22 normal subjects using the color Doppler,with one eyes as the timolo-treated eye and the contralateral eye as the auto-control eye in each individual.The result showed that,of the 2 groups of eyes,there was a sighificant increase in time average maximum velocity(TAMX),systolic peak velocity(Vs),and distolic velocity(Vd) in timolol-treated eyes.The resistance index in timolol-treated eyes was lower than in the control eyes(p<0.05). Significant linear correlation in the timolol-treated eyesfound between perfusion and TAMX.It is thought that the increase in volumetric blood flow rate by timolol is due to two concurrent processes:1.an indrect effect on the choroidal circulation through the increase in perfusion pressure; 2.a dirct effect on choroidal vessels resulting from action of drug on adrenergic receptors that is present in the choroidal vasculature. (Chin J Ocul Fundus Dis,1996,12: 83- 85)

    Release date:2016-09-02 06:21 Export PDF Favorites Scan
  • Study on Evaluation of Hemodynamic Changes of Portal Veins in Patients with Liver Cirrhosis by Color Doppler

    目的 分析彩色多普勒超声对肝硬化患者门静脉血流改变的评价作用。 方法 选择2010年1月-2011年4月收治的50例肝硬化患者作为观察组,其中代偿期患者27例,失代偿期患者23例;同时设置健康对照组50名,比较两组的门静脉内径(Dpv)、门静脉平均血流速度(Vpv)、门静脉血流量(Qpv)。 结果 观察组患者的Dpv增宽,Vpv减慢,Qpv减少,与对照组比较,差异均有统计学意义(P<0.05);且失代偿期患者的改变更为明显,与代偿期患者间差异有统计学意义(P<0.05)。 结论 彩色多普勒超声检查门静脉血流改变可以对肝硬化患者进行初步确诊。

    Release date:2016-09-08 09:13 Export PDF Favorites Scan
  • 视网膜脱离环扎手术后眼部血流动力学改变

    Release date:2016-09-02 06:12 Export PDF Favorites Scan
  • THE HEMODYNAMIC CHANGES AFTER END-TO-END ANASTOMOSIS OF THE SMALL ARTERIES IN RATS

    The hemodynamics changes of the common carotid arteries in 10 SD rats were measured with a color doppler flowmetry in an attempt to define the changes resulting from end-to-end anastomosis. The left common carotid arteries were divided and followed by end-to-end anastomosis. The systolic mean peak velocities in the left arteries were measured at the proximal, distal and anastomotic sites and in the right intact arteries as well at 6, 12, 24, 48, 72 and 120 hours after repair. The percentage of area reduction at anastomosis was calculated from these data. The results indicated that the systolic mean peak velocity at the anastomotic sites was significantly increased as compared to the velocity at the proximal, distal and contralateral sites (P lt; 0.05). The velocity at the distal sites was significantly lower than that from the proximal and contralateral sites (P lt; 0.05), the mean percentage of the reduction was 33.18% and 33.33%, respectively. From 6 hours to 120 hours after anastomosis of arteries there was various degree of narrowing at the site of anastomosis. The mean per cent of stenosis was 42.48%. It was concluded that from 6 to 120 hours after end-to-end anastomosis of the small arteries, the velocity at the anastomotic site was increased as compared to the velocities at pre- and post-anastomotic sites. The increase of velocity at the site of anatomosis was caused by stenosis at the anastomosis.

    Release date:2016-09-01 11:07 Export PDF Favorites Scan
  • EXTRACORPOREAL VENOUS BYPASS IN LIVER TRANSPLANTATION

    目的 观察体外静脉静脉转流对患者血流动力学的影响。方法原位异体肝移植患者14例,术中使用离心泵,部分肝素化方法行体外静脉转流。结果 体外静脉转流时间(98.9±23.6)min,转流量(1 168±260)ml/min,转流期及新肝5分钟心排血量(CO)明显下降,但仍维持在正常水平,体循环阻力(SVR)、肺循环阻力(PVR)转流30分钟后明显增加,心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、平均肺动脉压(MPAP)、肺毛细血管楔压(PCWP)等在转流期均无明显变化,新肝早期MAP明显下降,SVR明显增加。结论 无肝期采用离心泵行体外静脉转流,有助于稳定血流动力学,但新肝早期仍有明显血压下降,主要通过适量快速泵灌注全血来纠正。

    Release date:2016-08-28 05:30 Export PDF Favorites Scan
  • THE HEMODYNAMIC CHANGES ON SYSTEMIC AND PORTAL VEIN FLOW AND REGULATION WITH INDOMETHACIN IN OBSTRUCTIVE JAUNDICE

    Hemodynamic changes of systemic and portal vein flow and regulation of indomethacin have been studied in 73 patients with obstructive jaundice(group A)and 39 cases with simple gallbladder stones(guoup B).Obstructive jaundice was subgrouped into group A1(noindomethacin administration),group A2(preoperative administration of indomethacin),group A3(postoperative administration of indomethacin),and group A6(senile obstructive jaundice).Of them group A1 was subgrouped into group A4(malignant obstruction)and group A5(benign obstruction)again.The results showed that the stroke volum(SV),cardiac output(CO)and cardiac index (CI)were higher in each group of obstructive jaundice than those in group B(P<0.01),and the mean artery pressure (MAP),stroke vessel resistance (SVR)and portal vein blood flow(PVF)were lower in each group of obstructive jaundice than those in group B(P<0.01).The MAP,SVR and PVF in group A2 and group A3 showed better improvement than those in other subgroups,but as compared with group B there were significant differences (P<0.01).The authors consider that indomethacin can improve the circulation function,PVF and liver function in patients with obstructive jaundice.

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  • Application of computational fluid dynamics in the aortic root reconstruction

    ObjectiveTo investigate the application of computational fluid dynamics (CFD) in hemodynamic evaluation of aortic root reconstruction.MethodsThe clinical data of 1 patient with severe aortic valve stenosis was analyzed. Enhanced CT images were used as the original data, and professional software was used to reconstruct the three-dimensional (3D) model and fluid mechanics simulation of the aorta (including preoperative, postoperative and ideal conditions).ResultsThe 3D reconstruction model could directly present the distribution of valve calcification and the dilatation of the ascending aorta. The remodeled sinotubular junction and sinus structure were observed in the model under postoperative and ideal conditions. The improvement of ascending aorta dilatation was evaluated statistically by the diameter distribution before and after surgery. CFD simulation showed that the area of high flow velocity, pressure intensity and wall shear stress before surgery were consistent with the expansion area of the ascending aorta, and the restricted blood flow acceleration was observed at the angle between the arch and the descending aorta. In the ideal condition, the streamline of blood at the descending aorta was more stable and flat compared with preoperative or postoperative conditions, and there was no obvious abnormal high pressure and high wall shear stress area in the ascending aorta. The cardiopulmonary bypass time was 106 min, of which the aortic cross-clamp time was 60 min. The cardiac echocardiography indicated that the aortic valve worked well, and the peak systolic blood velocity was 1.7 m/s. The length of hospital stay after surgery was 12 d, including 2 d in ICU. The ventilator use time was 11.6 h. The patient did not have any remarkable discomfort during the 1-year follow-up.ConclusionCFD can be used to evaluate anatomic and hemodynamic abnormalities before aortic root reconstruction surgery. Postoperative reconstruction simulation can be performed again to evaluate the surgical effect, and meanwhile, virtual improvement can be tried for the unresolved problems to accumulate diagnosis and treatment experience, so as to provide patients with more accurate and personalized diagnosis and treatment procedure.

    Release date:2021-12-27 11:31 Export PDF Favorites Scan
  • Miels氏术患者体位对血流动力学影响的研究及护理干预

    目的:通过Miels氏术患者体位对血流动力学影响的研究,明确护理干预的措施。方法:将62例Miels氏术患者由截石位改平卧位及高血压、不同手术时间的患者体位改变时,心功能及血流动力学变化情况进行了比较和统计学处理。结果:62例患者中有45例体位改变时收缩压下降超过2.69 kPa以上,比文献报道高,高血压与手术时间3h以上组患者,除心率较对照组高外,各项心功能指标均下降,血流动力学变化差异有统计学意义。结论:有效的护理干预能预防患者体位改变时血流动力学波动,从而保证患者围手术期安全。

    Release date:2016-09-08 10:04 Export PDF Favorites Scan
  • COLOR DOPPLER ANALYSIS OF OCULAR VESSEL BLOOD VELOCITY IN NORMAL EYES

    OBJECTIVE :To investigate ocular vessel flow velocity in normal eyes by color Doppler imaging(CDI). METHODS: Ninety people (180 normal eyes)had flow velocity measured by CDI in three vessels,ophthalmic artery (OA),central retinal artery(CRA) and posterior ciliary artery (PCA),and the relations between velocity and affecting factors were analysed. RESULT: The diastolic and systolic velocity of OA,CRA and PCA were (31.7plusmn;10.9)cm/s, (7.2plusmn;2.6)cm/,s, (10.2plusmn;3.4)cm/s, (2.8plusmn;1.2)cm/s and (11.3plusmn;3.6)cm/s, (3.2plusmn;1.4)cm/s respectively. The velocity of OA had possitive correl-ativity with RBC,HCT and negative correlativity with age,while it revealed no relationship with sex, laterality of right or left eye,and normal IOP. CDI of ocular vessels in normal eyes is a triangle with three peaks and double sunkens in its frenquency spectum, revealed highly resistant,and both the pulsatility and resistive indexes were relatively high. The width of each frequency band basically was the same,and there was no obvious frequency window. CONCLUSION: The ocular application of CDI might lay the foundation of a comparatively comprehensive knowledge of the ocular hemodynamics. (Chin J Ocul Fundus Dis,1997,13: 99-101)

    Release date:2016-09-02 06:12 Export PDF Favorites Scan
  • Measurement Method of Arterial Shear Stress of Rats Model Based on Ultrasonic Particle Imaging Velocimetry

    The development and progression of atherosclerosis and thrombosis are closely related to changes of hemodynamics parameters. Ultrasonic pulse wave Doppler technique is normally used for noninvasively blood flow imaging. However, this technique only provides one-dimensional velocity and depends on the angle between the ultrasound beam and the local velocity vector. In this study, ultrasonic particle image velocimetry method was used to assess whole field hemodynamic changes in normal blood vessels. By using the polynomial fitting method, we investigated the velocity gradient and assessed the shear in different blood flow velocity of 10 healthy rats. It was found that using four polynomial fitting could result in optimal measurement results. The results obtained by ultrasonic particle image velocimetry accorded with the results obtained using Doppler technique. The statistical average of cyclical vessel wall shear stress was positively related to the locational mean velocity. It is proven that ultrasonic particle image velocimetry method could be used to assess directly the real-time whole field hemodynamic changes in blood vessels and was non-invasively, and should be a good prosperous technique for monitoring complex blood flow in stenotic arteries.

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