研究者詳細 - 玉川　雅章

論文 - 玉川　雅章

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Finite Difference Method for Electro-Osmotic Flow and Its Convergence 査読有り

Pearanat Chuchard, Masaaki Tamagawa and Somsak Orankitjaroen

ICIC Express Letters (An International Journal of Research and Surveys) 10 ( 11 ) 2773 - 2778 2016年11月

Computational fluid dynamics study of airflow and microparticle deposition in a constricted pharyngeal section representing obstructive sleep apnea disease 査読有り国際誌

Riazuddin V., Zubair M., Ahmadi M., Tamagawa M., Rashid N., Mazlan N., Ahmad K.

Journal of Medical Imaging and Health Informatics 6 ( 6 ) 1507 - 1512 2016年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Copyright © 2016 American Scientific Publishers All rights reserved. Developing a computational model to predict the abnormal flow characteristics and particle deposition produced by obstructive sleep apnea is an important step in learning the pathophysiology of Obstructive Sleep Apnea (OSA) disease. The objectives of this study are to investigate the airflow characteristics in the constricted airway region where obstruction could occur and to investigate the effect of abnormal airflow characteristics and microparticle deposition in the breathing airway due to pharyngeal occlusion. In this study, Computational Fluid Dynamics (CFD) analysis has been performed on an upper airway computational model with a constricted pharyngeal section representing Obstructive Sleep Apnea (OSA) disease. The different breathing rates of laminar and turbulent inspiratory airflows were simulated numerically through the upper airway model. The airflow characteristics and pressure distribution were analysed. A Lagrangian trajectory analysis approach was used to examine the transport and deposition of the injected microparticles through the nasal airways. The deposition fraction of the microparticles in a specific region through the upper airway model are presented. The results show that the morphology of the upper airway was found to significantly affect the airflow pattern and the deposition fraction of the microparticles. It was observed that, as the diameter of the particle increases, the location of the highest particle deposited will shift to the anterior part of the upper airway. The local deposition fractions proved that the upper airway plays a significant role in filtering large micro-particles.

DOI： 10.1166/jmihi.2016.1839

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The hemodynamic effects of paravalvular leakage using fluid structure interaction; Transcatheter aortic valve implantation patient 査読有り国際誌

Basri A., Zuber M., Zakaria M., Basri E., Aziz A., Ali R., Tamagawa M., Ahmad K.

Journal of Medical Imaging and Health Informatics 6 ( 6 ) 1513 - 1518 2016年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Copyright © 2016 American Scientific Publishers All rights reserved. In this study, the fluid structure interaction (FSI) method was utilized to investigate the hemodynamic effects between normal aorta and aorta with Transcatheter Aortic Valve Implantation (TAVI) of paravalvular leakage (PVL). A 3D model of patient specific aorta with annulus diameter of 27.3 mm was developed using MIMICS software. In this research, a similar TAVI valve model by referring to SXT 26 Edwards SAPIENT valve was drawn using CATIA software with valve opening of 100%. The two way of fluid structure interaction analysis has been performed using ANSYS 14.5 software (ANSYS Inc. Canonsburg, PA, USA). The results revealed that the undersized TAVI valve lead to PVL. It was noticed that the PVL happened at the gap in-between the TAVI valve and annulus diameter which is not completely round in shape. This phenomenon produced recirculation flow at the right side of ascending aorta after the flow passing through the valve. It has been proven that the PVL caused a huge impact on the losses of the mass flow rate and also recirculation of blood flow which may lead to blood thrombosis. Furthermore, the data shows that PVL causes higher aortic wall deformation instead of normal aortic condition and may lead to migration of the valve. Consequently, PVL may cause other serious problems such as stroke, arrhythmias and coronary ischemia, which required reoperation.

DOI： 10.1166/jmihi.2016.1840

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Numerical analysis using a fixed grid method for cardiovascular flow application 査読有り国際誌

Zakaria M., Ismail F., Tamagawa M., Aziz A., Wiriadidjaya S., Basri A., Ahmad K.

Journal of Medical Imaging and Health Informatics 6 ( 6 ) 1483 - 1488 2016年10月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Motivated by the current interest in the numerical simulation of biological flows in the human body, we develop a new method to simulate fluid flow embedded in a solid region. The novelty of this method lies on the use of a fixed grid in the entire computational domain. The formulation is an extension of the multiphase fluid flow that belongs to the category of the penalty method, where high viscosity is imposed on a solid region. A free open source library, namely, OpenFOAM, is used to integrate high order and advanced numerical schemes into these computational formulations. The Monotone Upstream System for Conservation Laws (MUSCL) scheme by van Leer, with a harmonic limiter from the category of the total variation bounded (TVB) scheme, is used for cell face interpolation. The robustness and accuracy of the solver are compared with the benchmark test case, namely, the free fall of a solid sphere. The test case validates that the rigidity of the solid sphere is ensured with the selected high viscosity ratio. The accurate terminal velocity of the falling solid sphere proves the no-slip condition at the solid-liquid interface. As a real application implementation, the flow on a simplified idealized model of heart valve stenosis is presented.

DOI： 10.1166/jmihi.2016.1835

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A special section on computational methods in health and biological sciences 査読有り国際誌

Ahmad K.A., Tamagawa M., Zuber M.

Journal of Medical Imaging and Health Informatics 6 ( 6 ) 1475 - 1477 2016年10月

Analysis of deformation process of a bubble in a capsule by pressure wave for developing drug delivery systems 査読有り国際誌

Tamagawa M., Oyama M., Ogasahara R.

ICIC Express Letters, Part B: Applications 7 ( 9 ) 2039 - 2044 2016年09月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper describes mathematical analysis of bubble deformation near free surface, which is the model of a gas bubble in a microcapsule collapsed by shock waves for drug delivery systems. By reviewing the previous investigations related to the disintegration of polymer capsules including gas bubbles by shock wave, it has been found that these modes depend on gas ratio in the liquid capsule, membrane thickness, pressure amplitude and frequency. This paper focuses on the effects of initial internal pressure of a bubble and gas ratio on the deformation process by simplified mathematical model, and it is compared with the previous experiments. The results showed that (1) the gas ratio does not affect oscillation amplitude of radius if the initial pressure is more than 0.4MPa; (2) the tendency of amplitude of radius with changing gas ratio in analysis is similar to the experimental averaged radius. It was concluded that the gas ratio and initial internal pressure are important parameters to control for making the micro capsule including a gas bubble.

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Analysis of Deformation Process of a Bubble in a Capsule by Pressure Wave for Developing Drug Delivery Systems 査読有り

Masaaki Tamagawa, Manami Oyama and Ryo Ogasahara

ICIC Express Letters, Part B: Applications (An International Journal of Research and Surveys) 7 ( 9 ) 2039 - 2044 2016年09月

Fast computer simulation method of thrombus formation on pipe orifice flow 査読有り国際誌

Numpanviwat N., Huabsomboon P., Tamagawa M.

ICIC Express Letters, Part B: Applications 7 ( 8 ) 1821 - 1826 2016年08月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper presents the performance of the parallel algorithm for simulating thrombus formation on pipe orifice flow by using a PETSc software library package. Since the computational cost for bio-fluid problems is very expensive, an efficient algorithm such as parallel computing is necessary in order to overcome this limitation. The parallel program reduces the computational time by dividing workload to calculate simultaneously for each processor or computer. This will help researchers and physicians for medical diagnosis and development of medical devices. The blood flow used in this analysis is modeled by the incompressible Navier-Stokes equations with a partially patched modified k − ϵ model. Moreover, the platelet adhesion model is used for predicting the formation of thrombus. We perform the numerical experiments on the orifice configuration. The results show that our program can reduce the computation time by increasing the number of processors.

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Fast Computer Simulation Method of Thrombus Formation on Pipe Orifice Flow 査読有り

Nattakarn Numpanviwat, Pallop Huabsomboon and Masaaki Tamagawa

ICIC Express Letters, Part B: Applications - Ijicic 7 ( 8 ) 1821 - 1826 2016年08月

Simulation of falling of human using a robot 査読有り国際誌

Nakano M., Matsuura H., Tamagawa M., Yukimasa T., Yamanaka M., Kubota M.

ICIC Express Letters, Part B: Applications ( ICIC International 学会 ) 7 ( 5 ) 1007 - 1012 2016年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016, ICIC International. All rights reserved. Accurate evaluation of turnover or fall accidents is necessary to understand the relation between HIC (Head Injury Criterion) and the way of falling. In order to investigate this problem, we have done the experiment in JARI using human-type robot which simulates the human accidental damage. The precise data of acceleration has been taken from three points of the robot (head, chest and pelvis), Using the acceleration data of head point, HIC has been calculated for two experiments. Furthermore, we construct the speeds and locations of the three points using the acceleration data of chest and pelvis. We found that there are two types of falling posture, convex and depression of the upper body, and this posture of falling is related on the largeness of HIC. Finally, we found the HIC of convex posture is smaller since the pelvis absorbs the shock of the impact.

DOI： 10.24507/icicelb.07.05.1007

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Finite difference method for electro-osmotic flow and its convergence 査読有り国際誌

Chuchard P., Tamagawa M., Orankitjaroen S.

ICIC Express Letters 10 ( 11 ) 2773 - 2778 2016年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 ICIC International. Electro-osmotic flow through a cylindrical tube is investigated numerically based on the finite difference method with the successive over relaxation (SOR) method using the Fortran language. The effect of the pressure weight parameter β and the tolerance τ of the SOR method on the SOR convergent rate and the maximum error of the continuity equation are examined. The results show that a low-value of β and a highvalue of τ give a good convergent rate of the SOR method. Moreover, the value of the external electric field plays an important role on the convergent rate of the SOR method but it has no impact on the maximum error of the continuity equation.

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連載講座「健康・医療における基盤工学研究の産業化」を終えて(<連載講座>「健康・医療における基盤工学研究の産業化」（第11回）)

須藤亮, 西田正浩, 玉川雅章, 和田成生

日本機械学会誌 ( 一般社団法人日本機械学会 ) 119 ( 1172 ) 420 - 421 2016年01月

Visualization of Thrombus Formation on Shear Flow and Numerical Simulation for the formation by Transport Equation

Tamagawa M., Yi Y., Hirayama C., Shi W.

Transactions of Japanese Society for Medical and Biological Engineering 54 Annual ( 28PM ) 2016年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（研究会，シンポジウム資料等）

This paper describes the visualization of thrombus formation on shear flows such as orifice flow and Cuette flow, and development of numerical simulation for predicting thrombus formation by transport equation. Using the transparent devices, the thrombus formation on the wall on shear flow is observed and obtained the rate of thrombus formation by image processing. The results showed that the thrombus rate is increasing with shear rate by changing geometries of orifice and rotational speed of Cuette flow. On the other hand, the prediction method using CFD including transport equation of species using modified shear dependent model in orifice flow and Cuette flow is developed. In this computation, activated platelet is evaluated. The results show that deposition rate of activated platelet is increasing with shear rate.

DOI： 10.11239/jsmbe.54Annual.S360

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Precise analysis of head deformation at falling shock 査読有り国際誌

Tamagawa M., Nakano M., Yukimasa T., Matsuura H., Yamanaka M.

2015 4th International Conference on Informatics, Electronics and Vision, ICIEV 2015 2015年11月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2015 IEEE. Accurate evaluation of fall accidents is very important. We have done the experiment in JARI using human-type robot which simulates the human accidental injury. The precise data of acceleration has been taken from the robot. Using the acceleration data, the motion of the head center is derived. The speed and the position of the head center are determined under a realistic condition. The deformation of head surface is also calculated and was found that it is 1.0∼1.2 mm in a natural falling. The solutions of a long interval of 324 ms are shown.

DOI： 10.1109/ICIEV.2015.7334020

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PS1-3 Prediction of Thrombus Formation on the Wall by High Shear Rate on Various Blood Flows(PS1: Poster Short Presentation I,Poster Session) 査読有り

YI Yingming, TAMAGAWA Masaaki, YOSHIKAWA Takanori, SHI Weiwei

Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics 2015 ( 8 ) 2015年09月

連載講座「健康・医療における基盤工学研究の産業化」を始めるに当たって査読有り

須藤亮, 西田正浩, 玉川雅章, 和田成生

日本機械学會誌 118 ( 1161 ) 2015年08月

Fractal Dimension of Cerebrovascular Branch Structure and Its Validation 査読有り

Nozikazu ISHIMATSU, Masaaki TAMAGAWA

ICIC Express Letters, Part B: Applications 6 ( 4 ) 1237 - 1242 2015年04月

Computational fluid dynamics study of the aortic valve opening on hemodynamics characteristics 査読有り国際誌

Basri A., Zubair M., Aziz A., Ali R., Tamagawa M., Ahmad K.

IECBES 2014, Conference Proceedings - 2014 IEEE Conference on Biomedical Engineering and Sciences: "Miri, Where Engineering in Medicine and Biology and Humanity Meet" 99 - 102 2015年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2014 IEEE. In this work, the 3D geometry of patient specific aorta was utilized to carry out CFD studies on the effect of different valve opening (45°,62.5° and fully opening) on the hemodynamic properties. The result shows that the lower valve opening induced jet flow and hampered the flow on the additional carotid arteries. Besides, the leaflets were subjected to extreme stress values having disastrous consequences. Consequently, stenosis which is characterized by weaker leaflets and low valve openings has serious impact on the well being of humans.

DOI： 10.1109/IECBES.2014.7047660

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Theoretical analysis of shock wave propagation 査読有り国際誌

Nakano M., Matsuura H., Tamagawa M., Yukimasa T., Yamanaka M., Kubota M.

ICIC Express Letters, Part B: Applications 6 ( 5 ) 1479 - 1484 2015年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2015. In order to understand the damage of human body and the related phenom-ena, the experiment of falling has been done in JARI, and acceleration data are taken on the head, chest, pelvis and also neck (force) using a dummy robot, which simulates a human body. However, micro movement of the center in the brain and deformation of the skull has not been clear from the experiment. Therefore, we calculate precisely the propagation of the shock waves after hitting the head. We formulate the two dimensional models, which simulate the skull material, and calculate the microscopic disorder of the each points using precise numerical procedure based on the fourth-order Runge-Kutta method. Then we obtain several interesting features of the shock waves. As conclusions, it is shown that (1) one dimensional calculation includes an essential feature of the propagation. (2) Based on the two dimensional calculation, the estimated speed of the longitudinal shock wave is 5263m/s and traverse shock wave is 2727m/s. (3) The method is ensured by the fact that the energy and momentum conservation low hold while calculation.

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Treatments of plankton and Escherichia coli cells using hybrid method with water cavitation and discharge plasma 査読有り国際誌

Ihara S., Itoh H., Kobayashi N., Inoue Y., Terato H., Tamagawa M.

IEEJ Transactions on Fundamentals and Materials 135 ( 6 ) 357 - 365 2015年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2015 The Institute of Electrical Engineers of Japan. In this study, we propose a new treatment method to sanitize ballast water contaminated with plankton and/or bacteria. This method is constituted of water cavitation and discharge plasma in this cavitation field. The 0.5% brackish water containing brine shrimp (2.5 × 10 4 and 1.25 × 10 5 m -3 ) was treated in 60 s. Then, we saw no surviving plankton in the treated water. Similarly, the treatment of water containing Escherichia coli cells (4 × 10 15 m -3 ) in 120 s completed the sterilization. We also observed the DNA damage and destruction of the cellular morphology after treatment. It seems that the mechanisms of sterilization are radical reactions and physical damage caused by shockwave, and radical reactions are dominant mechanism.

DOI： 10.1541/ieejfms.135.357

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