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World Journal of Clinical Cases 2019年第24期7卷 4245-4253页

作者： Jing-Jing Zhang Zong-Yang Qu Zhen Hua Ming-Zhang Zuo Hong-Ye Zhang Department of Anesthesiology Beijing Hospital National Center of Gerontology

BACKGROUND In recent years, with the popularity of laryngeal mask airway(LMA) for the management of clinical anesthesia, the influence of the LMA on the position and blood flow of the internal jugular vein(IJV) has attracted an increasing amount of *** To investigate the effect of placement of different types of LMA(Supreme LMA,Guardian LMA, I-gel LMA) on the position and blood flow of the right *** This was a prospective randomized controlled trial. A total of 102 patients aged 18-75 years who were scheduled to undergo laparoscopic abdominal surgery with general anesthesia were randomly assigned to three groups: Supreme LMA(group 1), Guardian LMA(group 2), and I-gel LMA(group 3) groups. The main indicator was the overlap index(OI) of IJV and the common carotid artery(CCA)at the high, middle, and low points before and after the placement of the *** second indicators were the proportion of ultrasound-simulated needle crossing the IJV and CCA, and the cross-sectional area and blood flow velocity of the IJV before and after placement of the LMA at the middle *** Data from 100 patients were included in the statistical analysis. The OI increased significantly after placement of the LMA in the three groups at the three points(Pblood flow velocity significantly decreased(P <0.01). There w

关键词： Laryngeal mask airway Internal jugular vein Common carotid artery blood flow

THEORETICAL AND COMPUTATIONAL INVESTIGATIONS OF NONLINEAR WAVE PROPAGATIONS IN ARTERIES(Ⅰ)——A THEORETICAL MODEL OF NONLINEAR PULSE WAVE PROPAGATIONS

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Science China Chemistry 1989年第6期32卷 711-728页

作者：伍时桂李兆治 Beijing Polytechnic University State University of New York BuffaloN Y 14260U.S.A.

In this paper, a new theoretical model of nonlinear wave propagations in arteries with surrounding tissues was put forward. The equations of motion for the blood vessels and their peripheral tissues as a system have been derived. These equations were expressed in terms of the stresses of the vessel wall and fluid, and the geometry of the blood vessel. They can be used to solve numerically the problems for the propagations of nonlinear pulse waves in arteries together with the momentum and continuity equations of incompressible-viscous flow, as well as the constitutive equations of fluid and vessel wall. The numerical solutions can involve pressure, velocities and flowrate of the blood flow, as well as displacements, velocities and stresses of the vessel wall. These physical variables of propagations of pulse waves in arteries are all of significance physiologically and clinically.

关键词： nonlinear waves theoretical model blood flow arterial walls surrounding tissue motion equations constitutive equation

Retinal tissue hypoperfusion in patients with clinical Alzheimer’s disease

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Eye and Vision 2018年第1期5卷 196-203页

作者： Giovana Rosa Gameiro Hong Jiang Yi Liu Yuqing Deng Xiaoyan Sun Bernardo Nascentes Bernard Baumel Tatjana Rundek Jianhua Wang Department of Ophthalmology Bascom Palmer Eye InstituteUniversity of Miami Miller School of Medicine1638 NW 10th AvenueMcKnight Building-Room 202AMiamiFL 33136USA Evelyn F.McKnight Brain Institute Department of NeurologyUniversity of Miami Miller School of MedicineMiamiFLUSA Department of Ophthalmology Third Affiliated Hospital of Nanjing University of Chinese MedicineNanjingChina State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangzhouGuangdongChina School of Nursing and Health Studies University of MiamiMiamiFLUSA

Background:It remains unknow whether retinal tissue perfusion occurs in patients with Alzheimer’s *** goal was to determine retinal tissue perfusion in patients with clinical Alzheimer’s disease(CAD).Methods:Twenty-four CAD patients and 19 cognitively normal(CN)age-matched controls were recruited.A retinal function imager(RFI,Optical Imaging Ltd.,Rehovot,Israel)was used to measure the retinal blood flow supplying the macular area of a diameter of 2.5 mm centered on the *** flow volumes of arterioles(entering the macular region)and venules(exiting the macular region)of the supplied area were *** blood flow was calculated as the average of arteriolar and venular flow *** ultra-high-resolution optical coherence tomography(UHR–OCT)was used to calculate macular tissue *** segmentation software(Orion,Voxeleron LLC,Pleasanton,CA)was used to segment six intra-retinal layers in the 2.5 mm(diameter)area centered on the *** inner retina(containing vessel network),including retinal nerve fiber layer(RNFL),ganglion cell-inner plexiform layer(GCIPL),inner nuclear layer(INL)and outer plexiform layer(OPL),was segmented and tissue volume was *** was calculated as the flow divided by the tissue ***:The tissue perfusion in CAD patients was 2.58±0.79 nl/s/mm^(3)(mean±standard deviation)and was significantly lower than in CN subjects(3.62±0.44 nl/s/mm^(3),Pflow volume was 2.82±0.92 nl/s in CAD patients,which was 31%lower than in CN subjects(4.09±0.46 nl/s,P<0.01).GCIPL tissue volume was 0.47±0.04 mm^(3) in CAD patients and 6%lower than CN subjects(0.50±0.05 mm^(3),P<0.05).No other significant alterations were found in the intra-retinal layers between CAD and CN ***:This study is the first to show decreased retinal tissue perfusion that may be indicative of diminished tissue metabolic activity in patients with clinical Alzheimer’s disease.

关键词： Clinical Alzheimer’s disease Retinal tissue perfusion blood flow Retinal tissue volume Hypoperfusion Retinal function imager Optical coherence tomography

FINITE ELEMENT GALERKIN APPROACH FOR A COMPUTATIONAL STUDY OF ARTERIAL flow

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Applied Mathematics and Mechanics(English Edition) 2001年第9期22卷 1012-1018页

作者： G.C.夏玛马德胡.珍阿尼尔.克乌玛 School of Mathematical Sciences Institute of Basic Science 282002 Khandari India

A finite element solution for the Navier_Stokes equations for steady flow through a double branched two dimensional section of three dimensional model of canine aorta is obtained. The numerical technique involves transformation of the physical coordinates to a curvilinear boundary fitted coordinate system. The shear stress at the wall is calculated for Reynolds number of 1000 with branch to main aortic flow rate ratio as a parameter. The results are compared with earlier works involving experimental data and it is observed that the results are very close to their solutions. This work in fact is an improvement of the work of Sharma and Kapoor (1995) in the sense that computations scheme is economic and Reynolds number is large.

关键词： shear stress blood flow arterial flow Galerkin approach

Factors Influencing the Disturbed flow Patterns Downstream of Curved Atherosclerotic Arteries

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Numerical Mathematics(Theory,Methods and Applications) 2008年第2期1卷 165-175页

作者： Biyue Liu Department of Mathematics Monmouth University West Long Branch Nd 07764 USA

Pulsatile blood flows in curved atherosclerotic arteries are studied by computer simulations. Computations are carried out with various values of physiological parameters to examine the effects of flow parameters on the disturbed flow patterns downstream of a curved artery with a stenosis at the inner wall. The numerical results indicate a strong dependence of flow pattern on the blood viscosity and inlet flow rate, while the influence of the inlet flow profile to the flow pattern in downstream is negligible.

关键词： Curved artery atherosclerosis blood flow wall shear stress flow pattern

MATHEMATICAL ESTIMATION OF PHYSIOLOGICAL DISTURBANCES IN HUMAN DERMAL PARTS AT EXTREME CONDITIONS:ONE DIMENSIONAL STEADY STATE CASE

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Analysis in Theory and Applications 2009年第4期25卷 325-332页

作者： M.A.Khanday V.P.Saxena University of Kashmir Srinagar India Jiwaji University India

A mathematical model for the thermoregulation in the dermal layers of the human body is proposed. The skin is composed mainly of three layers - epidermis, dermis and subcutaneous tissues. The relative constancy of the body temperature is remarkable because there is a continuous exchange of heat with the external environment as well as within the different compartments of the body. A model describes the distribution of dermal tempera- ture as a function of internal and external parameters, such as temperature of the incoming arterial blood, blood flow, ambient temperature, and heat exchange with the environment. It is shown that substantial changes in human dermal temperature can be accomplished only through changes in the temperature of the incoming arterial blood or substantial suppression of blood flow. Other parameters can lead only to temperature changes near the skin surface.

关键词： thermoregulation metabolism blood flow skin response bio-heat equation,mathematical model

THE　COUPLE　MOTION　BETWEEN　VESSEL　WALL　AN　Dblood　IN　THE　ENTRANCE　REGION　OF　A　TAPERED　VESSEL

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Applied Mathematics and Mechanics(English Edition) 1995年第1期16卷 17-25页

作者：岑人经秦婵谭哲东 South China University of Science and Technology Guangzhou

A problem of couple motion between vessel wall and blood in the entrance regionof a tapered vessel is considered in this paper A mathematical model of co-coupleaction is formed for both motion of vessel wall and blood flow in the entrance regance regionof elastic vessel with tapered angle. Under the situation that the relative boundary conditions are satisfied *** of velocity distribution formula. pressure distributionformula for the blood flow in a tapered elastic vessel are derived. Some importantconclusions are obtained.

关键词： vessel wall blood flow couple motion tapered angle

A pilot study of aortic hemodynamics before and after thoracic endovascular repair with a double-branched endograft

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Medicine in Novel Technology and Devices 2019年第4期4卷 7-23页

作者： Yu Zhu Wenbo Zhan Mohamad Hamady Xiao Yun Xu Department of Chemical Engineering Imperial College LondonUK Department of Interventional Radiology St Mary’s HospitalImperial College Healthcare NHS TrustLondonUK

Branched endografts have been developed to treat complex pathology in the aortic arch and ascending *** study aims to evaluate the haemodynamic performance of a double-branched thoracic endograft by detailed comparison of flow patterns and wall shear stress in the aorta and supra-aortic branches before and after stentgraft ***-and post-intervention CT images were acquired from two patients who underwent thoracic endovascular aortic repair(TEVAR)with a double-branched endograft for thoracic aortic *** images were used to reconstruct patient-specific models,which were analysed using computational fluid dynamics employing physiologically realistic boundary *** results showed that there was sufficient blood perfusion through the arch *** presence of inner tunnels caused flow derangement and asymmetric wall shear stress in the ascending aorta,where shear range index was up to 6 times higher than in the preintervention *** shear stress in the aortic arch increased considerably after intervention as a result of accelerated *** maximum flow-induced displacement forces on the branched endografts were around 22 N for both patients,which was below the threshold for device *** from this pilot study demonstrated that aortic flow patterns were significantly altered by the branched endograft which caused increased spatial variation of wall shear stress in the ascending aorta and the *** no obvious adverse hemodynamic features were found immediately after intervention for the cases we analysed,follow-up studies will be needed to assess durability of the device.

关键词： Thoracic endovascular aortic repair(TEVAR) Aortic arch Branched endograft blood flow Computational fluid dynamics

TRANSVAGINAL COLOR DOPPLER STUDY OF UTEROPLACENTAL CIRCULATION IN NORMAL EARLY PREGNANCY

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Journal of Pharmaceutical Analysis 1999年第2期13卷 170-175页

作者： Mu Junwu,Yin Yimin,Lei XiaoyingDepartment of Ultrasound, Second Affiliated Hospital, Xi′an Medical University,Xi Meiying  Department of Ultrasound, First Affiliated Hospital, Xi′an Medical University, Xi′an 710061 Department of Ultrasound First Affiliated Hospital Xi'an Medical University Xi'an 710061 China

A cross sectional transvaginal color Doppler study of the uteroplacental circulation was performed on 105 pregnant women with normal intrauterine pregnancy. Gestational age was ranged from 4 to 12 weeks. The blood flow velocity waveforms were obtained from four separate parts of the uteroplacental circulation: uterine, arcuate, radial, and spiral arteries. The resistance index (RI) and peak systolic velocity (PSV) were analyzed. The RI significantly decreased and PSV increased with advancing gestation in uterine artery and its branches (P<0 05). The RI gradully decreased from uterine artery through arcuate, radial to spiral arteries (P<0 05). At the same time, the PSV decreased from uterine artery then arcuate to radial artery, but PSV in spiral arteries were higher than that in radial artery (P<0 05). The results showed that transvaginal color Dopper ultrasonography was a simple, reliable method to assess the uteroplacental circulation in the early pregnancy; the detection of PSV was useful parameter for better understanding of physiological and pathophysiological hemodynamic changes as well as RI.

关键词： transvaginal color Doppler uteroplacental circulation early pregnancy blood flow

The exploration of flow pattern in the superior vena cava of healthy adults:A 4D flow magnetic resonance imaging study

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Medicine in Novel Technology and Devices 2023年第2期18卷 159-168页

作者： Huaxia Pu Haoyao Cao Yubo Fan Jinge Zhang Simeng Wang Zhan Liu Xiaoyue Zhou Ning Jin Tinghui Zheng Liqing Peng Department of Radiology West China HospitalSichuan UniversityChengdu610041China Department of Applied Mechanics Sichuan UniversityChengdu610065China Sichuan University Yibin Park Yibin Institute of Industrial TechnologyYibin644000China Key Laboratory for Biomechanics and Mechanobiology of the Ministry of Education School of Biological Science and Medical EngineeringBeihang UniversityBeijing100191China MR Collaboration Siemens Healthineers Ltd.Shanghai201318China Siemens Medical Solutions USA Inc.ChicagoIL60611USA Med-X Center for Informatics Sichuan UniversityChengdu610041China

Our study sought to investigate the blood flow pattern in the superior vena cava(SVC)of healthy adults and to describe the development and characteristics of the flow pattern using 4D flow magnetic resonance imaging(MRI).4D flow MRI data with full coverage of SVC and brachiocephalic veins(BVs)were acquired with a 3-Testa MRI in thirty healthy adults(age:28.70±9.09).Hemodynamic parameters in the SVC,including velocity,velocity vector,flow visualization(pathlines,streamlines),flow waveform and energy loss,were obtained with specialized commercial post-processing software based on 4D flow MRI *** study found that:(1)The SVC has a pulsating flow waveform with double peaks.(2)Based on BVs flow of the SVC pathline visualization,flow patterns could be divided into three development types:twining(n=14),untwining(n=)and no helical flow(n=7).(3)With the decreasing blood velocity,helical flow areas tended to gradually extend.(4)There were no significant differences in most hemodynamic parameters among the three *** exploration of the blood flow characteristics of normal SVC may be the first step for capturing pathogenic features before the patients develop symptoms with a certain positive *** potential physiological significance of these phenomena deserves more exploration in future studies.

关键词： Superior vena cava 4D flow magnetic resonance imaging blood flow Circulation