Numerical reproduction of hemodynamics change by acupuncture on Taichong (LR-3) based on the lumped-parameter approximation model of the systemic arteries

Atsushi Shirai,Takuya Suzuki,Takashi Seki 한국한의학연구원 2015 Integrative Medicine Research Vol.4 No.3

Background: The aim of this study was to develop a mathematical model of blood flow in the systemic circulation to emulate the change in hemodynamics by acupuncture therapy to elucidate the mechanism of the therapy. For this purpose, as a first step, a simple model of arterial blood flow was presented to reproduce previously reported change in the blood flow volume by the acupuncture needle stimulation of Taichong (LR-3). Methods: This model was based on the lumped-parameter approximation of arterial blood flow together with linear resistance of peripheral circulation. It has been reported that blood flow in the left arm was enhanced after the stimulation, yielding the peripheral vascular resistance-regulated blood flow dominated by the sympathetic nervous system. In addition to the peripheral resistance, another parameter that possibly regulates the blood flow is the cross-sectional area of the vessel. These two factors were changed to numerically examine their contributions to the blood flow based on the hypothesis that they could be changed by the stimulation. The numerical result was compared with the experimental result to confirm the validity of the hypothesis that the blood flow in the arm is regulated by the peripheral resistance. Results: This model is extremely simple and the physical parameters introduced for the simulation were gleaned from different reports in the literature. It was demonstrated, however, that regulation of the peripheral resistance rather than of the cross-sectional area could reproduce the experimentally observed change in the blood flow. Moreover, the relationship between the changes in the flow volume and the systemic vascular resistance quantitatively matched the experimental data. Conclusion: The present model has a potential to emulate hemodynamic change by acupuncture therapy by incorporating physiological correlation of stimulation of an acupoint and regulation of parameters that affect the hemodynamics.

암의 비대칭적 성장, 혈관생성 및 혈류역학에 대한 수치적 연구

김유석(Y. S. Kim),심은보(E. B. Shim) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Tumor hemodynamics in vascular state is numerically simulated using pressure node solution. The tumor angiogenesis pattern in our previous study is used for the geometry of vessel networks. For tumor angiogenesis, the equation that governed angiogenesis comprises a tumor angiogenesis factor (TAF) conservation equation in time and space, which is solved numerically using the Galerkin finite element method. A stochastic process model is used to simulate vessel formation and vessel. In this study, we use a two-dimensional model with planar vessel structure. Hemodynamics in vessel is assumed as incompressible steady flow with Newtonian fluid properties. In parent vessel, arterial pressure is assigned as a boundary condition whereas a constant terminal pressure is specified in tumor inside. Kirchhoff’s law is applied to each pressure node to simulate the pressure distribution in vessel networks. Transient pressure distribution along with angiogenesis pattern is presented to investigate the effect of tumor growth in tumor hemodynamics.

암의 혈관생성과 혈류역학에 대한 수치적 연구

김유석(Yoo Seok Kim),심은보(Eun Bo Shim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

Cancer hemodynamics in vascular state was numerically simulated using a pressure node equation. The cancer angiogenesis pattern in our previous study was used for the geometry of vessel networks. For cancer angiogenesis, the equation that governed angiogenesis comprises a cancer angiogenesis factor (TAF) conservation equation in time and space, which is solved numerically using the Galerkin finite element method. A stochastic process model is used to simulate vessel formation and vessel. In this study, we used a two-dimensional model with planar vessel structure. Hemodynamics in angiogenesis vessel was assumed as incompressible steady flow with Newtonian fluid properties. In parent vessel, arterial pressure is assigned as a boundary condition whereas a constant terminal pressure is specified in cancer inside. Kirchhoff’s law is applied to each pressure node to simulate the pressure distribution in vessel networks. Transient pressure distribution along with angiogenesis pattern was presented to investigate the effect of cancer growth on hemodynamics.

Where Is the “Optimal” Fontan Hemodynamics?

Hideo Ohuchi 대한심장학회 2017 Korean Circulation Journal Vol.47 No.6

Fontan circulation is generally characterized by high central venous pressure, low cardiac output, and slightly low arterial oxygen saturation, and it is quite different from normal biventricular physiology. Therefore, when a patient with congenital heart disease is selected as a candidate for this type of circulation, the ultimate goals of therapy consist of 2 components. One is a smooth adjustment to the new circulation, and the other is long-term circulatory stabilization after adjustment. When either of these goals is not achieved, the patient is categorized as having “failed” Fontan circulation, and the prognosis is dismal. For the first goal of smooth adjustment, a lot of effort has been made to establish criteria for patient selection and intensive management immediately after the Fontan operation. For the second goal of long-term circulatory stabilization, there is limited evidence of successful strategies for long-term hemodynamic stabilization. Furthermore, there have been no data on optimal hemodynamics in Fontan circulation that could be used as a reference for patient management. Although small clinical trials and case reports are available, the results cannot be generalized to the majority of Fontan survivors. We recently reported the clinical and hemodynamic characteristics of early and late failing Fontan survivors and their association with all-cause mortality. This knowledge could provide insight into the complex Fontan pathophysiology and might help establish a management strategy for long-term hemodynamic stabilization.

Korean Red Ginseng enhances cardiac hemodynamics on doxorubicin-induced toxicity in rats

Young-Jin Jang,Dongbin Lee,Mohammad Amjad Hossain,Adithan Aravinthan,Chang-Won Kang,Nam Soo Kim,Jong-Hoon Kim 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.3

Background: Korean Red Ginseng (KRG) has been known to possess many ginsenosides. These ginsenosidesare used for curing cardiovascular problems. The present study show the protective potential ofKRG against doxorubicin (DOX)einduced myocardial dysfunction, by assessing electrocardiographic,hemodynamic, and biochemical parameters and histopathological findings. Methods: Animals were fed a standard chow and adjusted to their environment for 3 days before theexperiments. Next, the rats were equally divided into five groups (n ¼ 9, each group). The animals wereadministered with KRG (250 and 500 mg/kg) for 10 days and injected with DOX (20 mg/kg, subcutaneously,twice at a 24-h interval) on the 8th and 9th day. Electrocardiography and echocardiographywere performed to study hemodynamics. Plasma levels of superoxide dismutase, catalase, glutathioneperoxidase, and malondialdehyde were measured. In addition, the dose of troponin I and activity ofmyeloperoxidase in serum and cardiac tissue were analyzed, and the histopathological findings wereevaluated using light microscopy. Results: Administration of KRG at a dose of 250 and 500 mg/kg recovered electrocardiographic changes,ejection fraction, fractional shortening, left ventricular systolic pressure, the maximal rate of change inleft ventricle contraction (þdP/dtmax), and left ventricle relaxation (-dP/dtmax). In addition, KRG treatmentsignificantly normalized the oxidative stress markers in plasma, dose dependently. In addition, thevalues of troponin I and myeloperoxidase were ameliorated by KRG treatment, dose dependently. And,KRG treatment showed better histopathological findings when compared with the DOX control group. Conclusion: These mean that KRG mitigates myocardial damage by modulating the hemodynamics,histopathological abnormality, and oxidative stress related to DOX-induced cardiomyopathy in rats. Theresults of the present study show protective effects of KRG on cardiac toxicity.

Korean Red Ginseng enhances cardiac hemodynamics on doxorubicin-induced toxicity in rats

Jang, Young-Jin,Lee, Dongbin,Hossain, Mohammad Amjad,Aravinthan, Adithan,Kang, Chang-Won,Kim, Nam Soo,Kim, Jong-Hoon The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.3

Background: Korean Red Ginseng (KRG) has been known to possess many ginsenosides. These ginsenosides are used for curing cardiovascular problems. The present study show the protective potential of KRG against doxorubicin (DOX)-induced myocardial dysfunction, by assessing electrocardiographic, hemodynamic, and biochemical parameters and histopathological findings. Methods: Animals were fed a standard chow and adjusted to their environment for 3 days before the experiments. Next, the rats were equally divided into five groups (n = 9, each group). The animals were administered with KRG (250 and 500 mg/kg) for 10 days and injected with DOX (20 mg/kg, subcutaneously, twice at a 24-h interval) on the 8th and 9th day. Electrocardiography and echocardiography were performed to study hemodynamics. Plasma levels of superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde were measured. In addition, the dose of troponin I and activity of myeloperoxidase in serum and cardiac tissue were analyzed, and the histopathological findings were evaluated using light microscopy. Results: Administration of KRG at a dose of 250 and 500 mg/kg recovered electrocardiographic changes, ejection fraction, fractional shortening, left ventricular systolic pressure, the maximal rate of change in left ventricle contraction (-dP/dt_max), and left ventricle relaxation (-dP/dt_max). In addition, KRG treatment significantly normalized the oxidative stress markers in plasma, dose dependently. In addition, the values of troponin I and myeloperoxidase were ameliorated by KRG treatment, dose dependently. And, KRG treatment showed better histopathological findings when compared with the DOX control group. Conclusion: These mean that KRG mitigates myocardial damage by modulating the hemodynamics, histopathological abnormality, and oxidative stress related to DOX-induced cardiomyopathy in rats. The results of the present study show protective effects of KRG on cardiac toxicity.

인간 심실모델에서의 혈류역학 해석

심은보(Eun Bo Shim),권순성(Soon Sung Kwon),김유석(Yoo Seok Kim),전형민(Hyung Min Jung) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

A 3D human ventricular model is proposed to simulate an integrative analysis of heart physiology and blood hemodynamics. This consists of the models of electrophysiology of human cells, electric wave propagation of tissue, heart solid mechanics, and 3D blood hemodynamics. The 3D geometry of human heart is discretized to a finite element mesh for the simulation of electric wave propagation and mechanics of heart. In cellular level, excitations by action potential are simulated using the existing human model. Then the contraction mechanics of a whole cell is incorporated to the excitation model. The excitation propagation to ventricular cells are transiently computed in the 3D cardiac tissue using a mono-domain method of electric wave propagation in cardiac tissue. Blood hemodynamics in heart is also considered and incorporated with muscle contraction. We use a PISO type finite element method to simulate the blood hemodynmaics in the human ventricular model.

대돈,소부 사법자침이 뇌혈류력학 변동 개선에 미치는 영향

신동훈,조명래 대한침구의학회 2004 대한침구의학회지 Vol.21 No.1

Experimental Study of Dadun(LR1)·Shaofu(HT8) Reduction in Acupuncture on the Improvement of Cerebral Hemodynamics Objective : The aim of this study was to investigate anti-ischemic effect of LR1·HT8 Reduction in Acupuncture Methods : I designed to investigate whether LR1·HT8 Reduction in Acupuncture affects cerebral hemodynamics〔regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP)〕in normal rats and to make manifest whether LR1·HT8 Reduction in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video microscope and width analyzer. Results : The results were as follows ; 1. LR1 Reduction in Acupuncture was increased rCBF and PAD, but decreased MABP. 2. HT8 Reduction in Acupuncture was significantly increased rCBF, but decreased MABP, and increased PAD. 3. LR1·HT8 Reduction in Acupuncture was significantly increased rCBF, PAD, but decreased MABP after withdrawing of the needle. This results suggest that LR1·HT8 Reduction in Acupuncture increased significantly rCBF by dilating PAD. 4. Pretreatment with indomethacin(1㎎/㎏, i.v.) was significantly inhibited LR1·HT8 Reduction in Acupuncture induced increase of rCBF and PAD, but increased LR1·HT8 Reduction in Acupuncture induced decrease of MABP after withdrawing of the needle. 5. Pretreatment with methylene blue(10㎍/㎏, i.v.) was decreased LR1·HT8 Reduction in Acupuncture induced increase of rCBF and PAD, but accelerated LR1·HT8 Reduction in Acupuncture induced decrease of MABP. Conclusions : I suggest that LR1·HT8 Reduction in Acupuncture has an anti-ischemic effect through the improvement of cerebral hemodynamics, and the mechanism is mediated by cyclooxygenase.

大敦?少衝?少府 刺鍼이 腦血流力學에 미치는 영향

박은주,조명래 대한침구의학회 2007 대한침구의학회지 Vol.24 No.1

Objection : The aim of this study was to investigate anti-ischemic effect of LR1,HT8,HT9 Reinforcement in Acupuncture. Methods : I designed to investigate whether LR1,HT8,HT9 Reinforcement in Acupuncture affects cerebral hemodynamics〔regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP)〕in normal and cerebral ischemia rats by MCA occlusion method, and to make manifest whether LR1,HT8,HT9 Reinforcement in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video microscope and width analyzer. Results : The results were as follows ; 1. LR1,HT8,HT9 Reinforcement in Acupuncture was significantly increased rCBF, PAD, but decreased MABP after withdrawing of the needle. This results suggest that LR1,HT8,HT9 Reinforcement in Acupuncture increased significantly rCBF by dilating PAD. 2. Pretreatment with indomethacin(1㎎/㎏, i.v.) was significantly inhibited LR1,HT8,HT9 Reinforcement in Acupuncture induced increase of rCBF and PAD, but increased LR1,HT8,HT9 Reinforcement in Acupuncture induced decrease of MABP after withdrawing of the needle. 3. Pretreatment with methylene blue(10㎍/㎏, i.v.) was decreased LR1,HT8,HT9 Reinforcement in Acupuncture induced increase of rCBF and MABP, but accelerated LR1,HT8,HT9 Reinforcement in Acupuncture induced decrease of PAD. This results suggest that the mechanism of LR1,HT8,HT9 Reinforcement in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. Conclusion : I suggest that LR1,HT8,HT9 Reinforcement in Acupuncture has an anti-ischemic effect through the improvement of cerebral hemodynamics, and the mechanism is mediated by cyclooxygenase.

Hemodynamic Principles in Free Tissue Transfer: Vascular Changes at the Anastomosis Site

GyeongHyeon Doh,김범식,DongYun Lee,윤정수,SooA Lim,한예식,SuRak Eo 대한수부외과학회 2021 대한수부외과학회지 Vol.26 No.4

Purpose: Various factors such as blood velocity, turbulent flow,and intimal injury are the most basic elements in free tissue transfers. However, how blood flow is reestablished, maintained, and changed after vascular anastomosis has rarely been studied. Methods: A 54-year-old male sustained an unreplantable severe crushing injury to his right hand. The middle finger was transferred to the thumb as an ectopic replantation using an anastomosis between the radial and digital arteries. However, secondary reconstruction for the first web space defect was inevitable and an anteromedial thigh free flap procedure was performed 2 months later using the previously anastomosed vessels. During the procedures, we noted morphologic changes in the microvessels and tried to explain those phenomena by applying the principles of hemodynamics. Results: Due to the discrepancy in vascular size between the radial and digital arteries, the velocity of the blood flow in the post-anastomotic site, which was the digital artery, must have been increased by Poiseuille’s law. Supposing that the velocity through the post-anastomotic site of the digital artery was increased, the pressure exerted by that flow decreased, resulting in more shrinkage of the vessel lumen of the digital artery by Bernoulli’s principle. Pascal’s law could also be applied in confined spaces with a static flow; where there is a constant pressure, as the radius of the post-anastomotic digital artery diminishes, the tension within the digital artery’s wall also simultaneously decreases. By Laplace’s law, the post-anastomotic digital artery’s wall thickens as less tension is exerted on the wall. Conclusion: Understanding these simple flow mechanics will enable microsurgeons to better avoid the risk factors causing thrombosis, which is related to flap failure.