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EFFECTS OF PARENT ARTERY SEGMENTATION AND ANEURISMALWALL ELASTICITY ON PATIENT-SPECIFIC HEMODYNAMIC SIMULATIONS

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Journal of Hydrodynamics 2011年第5期23卷 660-668页

作者： CHEN Jia-liang ding guang-hong YANG Xin-jian LI Hai-yun Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China Beijing Institute of Neurosurgery Beijing 100050 China Department of Biomedical Engineering Capital Medical University Beijing 100050 China

It is well known that hemodynamics and wall tension play an important role in the formation, growth and rupture of aneurysms. In the present study, the authors investigated the influence of parent artery segmentation and aneurismal-wall elasticity on patient-specific hemodynamic simulations with two patient-specific cases of cerebral aneurysms. Realistic models of the aneurysms were constructed from 3-D angiography images and blood flow dynamics was studied under physiologically representative waveform of inflow. For each aneurysm three computational models were constructed： Model 1 with more extensive upstream parent artery with the rigid arterial and aneurismal wall, Model 2 with the partial upstream parent artery with the elastic arterial and aneurismal wall, Model 3 with more extensive upstream parent artery with the rigid wall for arterial wall far from the aneurysm and the elastic wall for arterial wall near the aneurysm. The results show that Model 1 could predict complex intra-aneurismal flow patterns and wall shear stress distribution in the aneurysm, but is unable to give aneurismal wall deformation and tension, Model 2 demonstrates aneurismal wall deformation and tension, but fails to properly model inflow pattern contributed by the upstream parent artery, resulting in local misunderstanding Wall Shear Stress （WSS） distribution, Model 3 can overcome limitations of the former two models, and give an overall and accurate analysis on intra-aneufismal flow patterns, wall shear stress distribution, aneurismal-wall deformation and tension. Therefore we suggest that the proper length of extensive upstream parent artery and aneurismal-wall elasticity should be considered carefully in establishing computational model to predict the intra-aneurismal hemodynamic and wall tension.

关键词： cerebral aneurysm fluid-structure interaction upstream parent artery wall tension hemodynamics

A LINEAR DYNAMIC MODEL DESCRIBING LYMPH CIRCULATION

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Journal of Hydrodynamics 2009年第1期21卷 118-123页

作者： YAO Wei WANG Sheng-zhang ding guang-hong SHEN Xue-yong Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China Shanghai Research Center of Acupuncture and Meridian Shanghai 201203 China Acupuncture Department of Shanghai University of Traditional Chinese Medicine Shanghai 200032 China

The lymph circulation plays an important role in interstitial fluid balance, protein transport, and immune system. However, its mechanism is poorly understood, and associated pathologies are mostly untreatable. By following Sungawa＇s method of discussing the heart output, a hemodynamic model of lymph circulation was set up. The model was used to demonstrate how the lymphatic fluid formation, investigate the relationship between the lymph flow rate QL and physiological parameters, and explore how local massage influences QL Computer simulation results show that QL is linearly proportional to the interstitial fluid pressure P~, which is similar to experimental observations. Comparing the simulated value of QL during the massage of different frequency with the experimental data from Ikomi shows that they are identical, which indicates that the presented model is rational to explain the mechanism of massage treatment in traditional Chinese medicine （TCM）.

关键词： lymph circulation pressure-volume circle equivalent elastance massage treatment in TCM

PATIENT-SPECIFIC BLOOD DYNAMIC SIMULATIONS IN ASSESSING ENDOVASCULAR OCCLUSION OF INTRACRANIAL ANEURYSMS

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Journal of Hydrodynamics 2009年第2期21卷 271-276页

作者： CHEN Jia-liang WANG Sheng-zhang ding guang-hong YANG Xin-jian LI Hai-yun Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China Beijing Institute of Neurosurgery Beijing 100050 China Department of Biomedical Engineering Capital Medical University Beijing 100050 China

According to recent studies, there are various potential predictors for surgical outcome for cerebral aneurysms. An accurate surgical outcome assessment would help make better-informed decisions and avoid the risk of rebleeding. It is well known that hemodynamic factors play an important role in the pathogenesis and treatment of intracranial aneurysms. In this article, a computational fluid dynamic analysis is applied to one patient-specific model of the cerebral aneurysm located at the tip of basilar artery, by which the differences of hemodynamic parameters before and after endovascular treatment may be evaluated. Based on the model, we show that the flow behavior near the neck of the aneurysm sees great differences after endovascular treatment as compared with that before treatment, which also affects the wall shear stress and the displacement distribution. In addition, our whole simulation process is based on a series of CFD commercial software packages, which are easily available for doctors to implement such a method in their daily practice. These results would be used to assess the outcome of endovascular treatment for the aneurysm occlusion.

关键词： hemodynamics numerical simulation intracranial aneurysm

NUMERICAL SIMULATION AND ANALYSIS ON THE HEMODYNAMICS OF AN ELASTIC ANEURYSM

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Journal of Hydrodynamics 2008年第2期20卷 216-224页

作者： ZHAO Jun-wei YIN Wen-yi ding guang-hong YANG Xin-jian SHI Wan-chao ZHANG Xiao-long Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China Beijing Institute ofNeurosurgery Beijing 100050 China Huashan Hospital Affiliated to Fudan University Shanghai 200040 China

Intracranial aneurysms are pathological dilatations which endanger people＇s health. Hemodynamics is thought to be an important factor in the pathogenesis and treatment of aneurysms. To date, the bulk of investigations into hemodynamics have been conducted by making use of mathematically idealized models for rigid aneurysms and associated arteries. However the walls of aneurysms and associated arteries are elastic in vivo. This study shows the differences of the simulation between elastic and rigid wall models. The numerical simulation of elastic aneurysm model is made fi＇om a representative Digital Subtraction Angiography （DSA） image and calculated with CFD software to get the wall deformation and the velocity field. Then the results are analyzed. By comparing the simulation results of the two models from their velocity vectors and shear stress distribution, many differences can be noted. The main difference exists in the distribution of velocity magnitude at some sections, with one outlet having obviously off-center distribution for the elastic wall model. The currents of the distribution of wall shear stress along the wall of aneurysm simulated in rigid and elastic wall models were similar. But there were apparent differences between the two models on the values of wall shear stress especially at the neck of aneurysm. The off-center distribution of velocity magnitude affects the distribution of wall shear stress and the exchange of substance through the wall. The analysis demonstrated clearly that the results of 2-D elastic numerical simulation were in good agreement with the clinical and pathological practice. The results of this study play an important role in the formation, growth, rupture and prognosis of an aneurysm on clinic application.

关键词： aneurysm 2-D numerical simulation elastic wall medical image

THE PHENOMENON ON COLLAPSIBLE TUBE DISPLACEMENT OSCILLATION AND ITS THEORETICAL ANALYSIS

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Journal of Hydrodynamics 1989年第4期1卷 67-78页

作者： Liu Zhao-rong ding guang-hong Applied Mechanics Department,Fudan University,Shanghai,P.R.China

In this paper,the phenomenon on collapsible tube displacement oscillation,a new behavior of the collapsible tube puisatile flow has been *** experiments show that the collapsible tube,in which the flow is periodic puisatile in the upstream,will oscillate as a simple supported beam when it is collapsed to certain extent,and that if the tube is collapsed continue,this oscillation will tend to weak and completely disappear *** analytical model corresponding to the collapsible tube displacement oscillation and its governed equations are set up from the experiment *** analysing the model and solving the equations, the collapsible tube displacement oscillation pattern and the oscillation occurring or disappearing criterion are *** results predicted by this study are in agreement with those observed from experiment phenomena.

关键词： THE PHENOMENON ON COLLAPSIBLE TUBE DISPLACEMENT OSCILLATION AND ITS THEORETICAL ANALYSIS As Flow ITS

A FLUID MECHANICS MODEL OF TISSUE FLUID FLOW IN LIMB CONNECTIVE TISSUE——A MECHANISM OF ACUPUNCTURE SIGNAL TRANSMISSION

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Journal of Hydrodynamics 2009年第5期21卷 675-684页

作者： ZHANG Di YAO Wei ding guang-hong YANG Jing SCHWARZ Wolfgang FEI Lun LIU Fang SHEN Xue-yong LAO Li-xing Shanghai Research Center of Acupuncture and Meridian Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China Anatomy Department of the Second Medical University of PLA Shanghai 200433 China Acupuncture College Shanghai University of Traditional Chinese Medicine Shanghai 200032 China Center for Integrative Medicine University of Maryland School of Medicine Baltimore MD 21201 USA

This article explores the mechanisms of acupuncture meridians by determining characteristics of the tissue fluid flow in the connective tissue along meridians. Based on deep dissection of acupoints on the upper and lower limbs of the human body and micro and macro observation and measurement, a mathematical model of the flow of tissue fluid in interosseous membranes is constructed. It is shown that the signal transmission along acupuncture meridians may be determined by unique anatomical and physiological factors that govern the flow of tissue fluid in the connective tissue and involve mast cell degranulation. Our results provide a preliminary explanation of the phenomenon of the ＂de qi＂ sensation and the mechanism of acupuncture signal transmission along acupuncture meridians.

关键词： acupuncture meridian tissue-fluid flow mast cell

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模拟卒中脑血流和心室做功变化的动力学模型

中国生物医学工程学报 2013年第3期32卷 321-330页

作者：徐又为丁光宏复旦大学力学与工程科学系上海200433

分析脑卒中对心室做功的影响以及与高血压的关联性,为卒中和脑心综合症等心脑血管疾病的预警提供血液动力学依据。基于非对称T型管,建立心脑血管耦合的血液动力学模型,计算和分析动脉血液动力学行为;通过提高脑外周阻力和降低血管弹性,... 详细信息

分析脑卒中对心室做功的影响以及与高血压的关联性,为卒中和脑心综合症等心脑血管疾病的预警提供血液动力学依据。基于非对称T型管,建立心脑血管耦合的血液动力学模型,计算和分析动脉血液动力学行为;通过提高脑外周阻力和降低血管弹性,数值模拟在大脑动脉血管病变的情况下血压、脑血流量和心室做功功率的变化趋势。研究表明,相对于正常情况,卒中患者其脑外周阻力显著提高,脑阻力达到正常值2倍以上的占统计总人数的83%;其血压(尤其是收缩压和脉压)会明显高于正常值,模拟的收缩压达到140 mmHg以上;其脑部血液流量存在代偿流动和调节;其心室外功的总功率以及振荡功率占总功率的比例均增加,增加幅度达到10%以上。卒中患者的心室做功受到脑血管病变的影响,因而在治疗卒中的同时应加强对心脏的保护。

关键词：脑卒中非对称T型管心室做功功率脑血液流量

Mathematical Analysis of Yin-Yang Wu-Xing Model in TCM

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Journal of Acupuncture and Tuina Science 2008年第5期6卷 269-270页

作者：丁光宏王涛 Shanghai Research Center of Acupuncture and Meridians Shanghai 201203P.R.China Fudan UniversityShanghai 200433P.R.China

According to Traditional Chinese Medicine, the functional structure of human body is composed of five functional subsystems which are based on the five-organs concept, and the relationship between them could be expatiated with Wu-Xing （Five-Elements） theory. Wu-Xing system is taken as our research object. The dynamic model has the characteristic of self-organization. There is only one stable point with local stability in the five-dimensional space. There exists an instability domain in the five-dimensional space. The stability domain is unbounded; it contains some special subdomains, including rectilineal subdomains, ray subdomains and line subdomains. In some ray subdomains, there exists ＂comeback summits＂, the peak value of the comeback summit is comeback threshold. The existence of the comeback threshold means that, if the human body wants to go back to the healthy state from a certain special state which corresponded to the initial conditions located in a domain with comeback summit, it has to get across the comeback threshold. The comeback threshold is the division of the healthy state and the sub-healthy state. Some research work is done to investigate the response of the Wu-Xing dynamic model to the impact stimulation, and results in the decrease of the system＇s comeback threshold. There are 3 manners to achieve this goal, and they tally with the principle of the Wu-Xing system and the experimental rules in clinic.

关键词： Five-Elements Traditional Medicine. Chinese Models. Theoretical

穴区肥大细胞功能与针刺缓解急性佐剂性关节炎大鼠疼痛效应的关系

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针刺研究 2007年第1期32卷 16-19页

作者：林俊黄红丁光宏张迪复旦大学力学与工程科学系上海200433

目的:通过观察针刺镇痛效应与穴位区肥大细胞脱颗粒率的变化,研究针刺效应与穴位局部的肥大细胞功能之间的关系。方法:58只SD雄性大鼠随机分为正常组、模型组、留针组(仅留置针体在穴位处)、电针(EA,2/100Hz,0.5/1.0/1.5mA,“足三里”)... 详细信息

目的:通过观察针刺镇痛效应与穴位区肥大细胞脱颗粒率的变化,研究针刺效应与穴位局部的肥大细胞功能之间的关系。方法:58只SD雄性大鼠随机分为正常组、模型组、留针组(仅留置针体在穴位处)、电针(EA,2/100Hz,0.5/1.0/1.5mA,“足三里”)组和手针(MA)组,在急性佐剂性关节炎(AA,完全弗氏佐剂0.05mL注射于动物踝关节)大鼠模型上,采用辐射热缩爪反射的方法,以大鼠缩爪反射的潜伏期为观察指标,比较电针、手针和留针组的镇痛效果。将穴位区的组织块制成石蜡切片,用甲苯胺蓝特殊染色法染色,观察其中肥大细胞变化的情况。结果:电针和手针对AA大鼠都有很明显的镇痛效应(与留针组比较P0.05),其中手针穴位处的效果更明显于电针。同时,电针和手针组的组织切片中肥大细胞脱颗粒率明显高于留针组(P<0.01)。结论:穴位组织中的肥大细胞在针刺镇痛效应的产生过程中起着重要作用,肥大细胞脱颗粒参与了针刺镇痛效应中针刺信号从穴位向靶器官传输与转换的过程。

关键词：穴位肥大细胞脱颗粒率针刺镇痛