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Kiyoshi Kumahata, Koji Nishiguchi, Shigenobu Okazawa, Akira Amano, Ter ...
Article type: Article
Session ID: J0206-2-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Today an actual human heart shape is easily obtained as a voxel data via medical images. To assist the diagnosis and treatment in daily medical scene, our final goal is the realistic blood flow simulation of an actual heart using the voxel data. Because blood flow is driven by heart contraction and the contraction occurred by cardiomyocyte cell behavior, and the heart shape influences the cell behavior at each time. Therefore it is necessary to consider the fluid-structure interaction driven the cardiomyocyte behavior that is cause of heart wall moving. Although structure behavior is usually simulated based on the Lagrangian frame, we are studying the fluid-structure interaction simulation based on the Eulerian frame. In this simulation, both phenomena flow and structure are calculated by same way based on the same equation in the Eulerian grid. And the force computed by the cardiomyocyte model "Kyoto Model" drives the heart wall contraction. This interaction simulation system simulated a driving blood flow by cardiomyocyte contraction model.
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Futoshi MORI, Hiroshi OHTAKE, Junichiro SANADA, Keiichi KIMURA, Osamu ...
Article type: Article
Session ID: J0206-2-5
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Careful section of the surgical technique is necessary. Diagnosis by computed tomography (CT) is currently used. CT can retrospectively reveal changes. However, predictions of the occurrence in the thrombosed aortic dissection have not been reported. The study is designed to predict development, progression, and rupture of an aneurysm using time series medical images obtained before development, after development, and immediately before rupture for computed fluid dynamics. Dynamic stress is a risk factor for the development, progression, and rupture of an aneurysm of the thrombosed aortic dissection. The purpose of this study is to identify predictive hemodynamic factors. Useful diagnostic information can be obtained by combining a clinical diagnosis with the results of fluid dynamics simulations.
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Kazutoshi MIYASHITA, Koichi SUGIMOTO, Fuyou LIANG, Ken-ichi TSUBOTA, H ...
Article type: Article
Session ID: J0206-2-6
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Aiming at establishing a simulation-based framework for predictive medicine we have developed a patient-specific aortic aneurysm model based on computational biomechanics. In this study, we construct two image-based three-dimensional patient-specific models of aortic aneurysms based on CT images of two patients. A multi-scale hemodynamic model is employed to couple these three-dimensional models with a closed-loop 0-1-dimension hemodynamic model for the whole cardiovascular system. The aortic aneurysm hemodynamics are then visualized in terms of streamlines, wall shear stresses and oscillatory shear index, and further analyzed with a specific focus on the relationship between the hemodynamics and the occurrence of the aortic aneurysm.
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Kazuyasu SUGIYAMA, Satoshi II, Shintaro TAKEUCHI, Shu TAKAGI, Yoichiro ...
Article type: Article
Session ID: J0206-3-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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A full Eulerian simulation method for solving fluid-structure coupling problems has been developed. It facilitates solution of dynamic interaction problems between Newtonian fluid and hyperelastic material for given initial configuration of a multi-component geometry described by voxel-based data on a fixed Cartesian mesh. The monolithic velocity field defined over the fluid and solid domains is discretized on a fixed mesh in a finite difference manner. A solid volume fraction and a left Cauchy-Green deformation tensor are temporally updated on the Eulerian frame to distinguish between two phases and to quantify the deformation level of solid, respectively. The simulation method is applied to two-dimensional motions of biconcave neo-Hookean particles in a Poiseuille flow.
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Satoshi II, Kazuyasu SUGIYAMA, Shu TAKAGI, Yoichiro MATSUMOTO
Article type: Article
Session ID: J0206-3-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The main idea of the Eulerian fluid-structure interaction (FSI) model is derived from the idea of the multi-phase analysis on fixed Cartesian mesh. The volume fraction data is used to distinguish the fluid and structure regions, and the mixed stress on an Eulerian element is calculated with each volume fraction. In order to describe the structure deformation, which relates to the elastic stress, the left Cauchy-Green deformation tensor is introduced in a hyper-elastic material. In this paper, further development for the numerical approach is proposed such as the advection scheme of the volume data and implicit treatment for the elastic stress. The simple validation problems will be shown, and a pressure-driving capillary flow involving several biconcave materials will be also investigated.
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Naohiro NAGANO, Kazuyasu SUGIYAMA, Shintaro TAKEUCHI, Satoshi II, Shu ...
Article type: Article
Session ID: J0206-3-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Abstract An interaction problem between a fluid and elastic walls is solved by a full Eulerian fluid-structure coupling method. The method employs a uniform grid system for both fluid and solid and it does not require any mesh generation or reconstruction, aming at facilitating the practical bio-mechanical fluid-structure analysis. The availability and applicability of the developed method to systems involving complex geometries driven by a pressure gradient are shown through a comparison between the obtained numerical results and theoretical prediction, and a grid convergence test. Further, pulsating flow simulation are performed to demonstrate the effect of the pulsating amplitude on the flow rate.
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Masato YASUI, Kenichiro KOSHIYAMA, Shigeo WADA
Article type: Article
Session ID: J0206-3-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The lung has a very complicated porous structure composed of millions of alveoli. Modeling of the lung microstructure is important for various numerical analyses such as computation of stress distribution in the lung with mechanical ventilation. In this paper we have developed a new technique to model the lung microstructure using phase-field method. This method allows us to model varied structures by changing the numbers or shape of nuclei, which are the origins of alveoli. In addition, we have modeled the realistic structures of lung microstructure (alveolar duct and alveolar sac) by using columnar shaped nucleus. Moreover, we analyzed the local stress distribution in the lung microstructure model that is assumed to be inflated by ventilator. We found that the 3^<rd> principal stress is high near the connection of alveolar walls, the 1^<st> principal stress has no feature, and the 3^<rd> principal stress at the connection increases with the increase of the region volume or with the decrease of alveolar pressure.
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Yasuhiro ISHIMINE, Toshihiro SERA, Shigeho NODA, Shingo SUZUKI, Shigeo ...
Article type: Article
Session ID: J0206-3-5
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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This paper describes preliminary results of our CFD analysis that investigates respiratory flows in a human lung. Our study focuses on micro-scale airflows in peripheral airways, including respiratory bronchioles and alveoli. The complicated geometry of a human lung is described with rectangular uniform calculation cells combined with VOF functions in our numerical model. This feature clearly distinguishes our approach from conventional work based on finite element methods (FEM) using boundary-fitted unstructured mesh. We adopt the former approach because we aim at developing software that facilitates clinicians to promptly carry out numerical simulations in hospital by using digital data such as X-ray CT images without consuming time and effort for the generation a calculation mesh to diagnose and treat their patients. We calculated some low-Reynolds-number flows with simple geometries consisting of some spheres and a cylinder to test the validity of our numerical model and obtained fairly good results.
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Shingo SUZUKI, Shigeho NODA, Shu TAKAGI, Shigeo WADA
Article type: Article
Session ID: J0206-3-6
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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We simulated the pulmonary airflow using a 1D model of branching airway based on the clinical CT images of lung. The pressure and velocity profiles were obtained by solving the equations of continuity and motion of air flowing in the elastic airway with the mechanics of lung parenchyma. There was no significant difference in the distribution of pressure in the airway between the results obtained 1D and 3D airway models. The individual-dependent airway resistance also found during the respiratory cycles. These results indicate that the 1D model can be applied to develop a model of airflow in the whole airway systems. We also examined to simulate the forced oscillation technique which measured the respiratory impedance to assess in patients with COPD.
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Takeshi ISHIDA
Article type: Article
Session ID: J0206-4-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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It is thought that the reveal of generalized mechanism of hierarchical morphosis phenomena of living system is the fundamental of various field, such as mass-production of molecular machines of nanotechnology, artificial synthetic of biology, and so on. This study developed the model to simulate the morphogenetic mechanism of cells under the condition of two-dimensional cellular automata. We considered not only the state transition rules but also the concentration diffusion of the field. Thus our model was able to simulate morphogenetic formation in few state transition rules.
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Nozomi OSHIKA, Nobutaka MAEZAKI, Tsutomu EZUMI
Article type: Article
Session ID: J0206-4-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Sleep is indispensable to human acts. However, the sleep disturbance is one of the matters of social problem now. The topic concerning sleep came to be often taken up in media. And the attention of bedding has increased Especially, the pillow attracts a lot of attention. In this study, we paid attention to the pillow and cervica vertebrae. It aims to examine the dynamic influence that pillow exerts on spine position. The experiment uses the photoelastic method.As a result, the stress in the cervical vertebrae has been understood to concentrate on the top part and the bottom part.
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Hidetaka MORITA, Seiya MIYAZAKI, Kazuhiko ICHIHARA, Shunichi KAWANO, J ...
Article type: Article
Session ID: J0206-4-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The posterior longitudinal ligament might be ossified and enlarged with aging, and then the cervical spinal cord around the ligament is compressed. As the results, numbness of a limb and disturbance of perceptions which are paralysis of pain and/or temperature senses occur in human body. In this paper, the stress distributions in the cervical spinal cord compressed by ossificated posterior longitudinal ligament were calculated by two-dimensional finite element method and the effect of the shape of the ossificated posterior longitudinal ligament on the stress distributions were investigated. The stresses were concentrated around the anterior horn and dorsal horn in the gray matter and lateral funiculus in the white matter in the case of flat ossificated ligament (α = 0°), and center part of spinal cord in the case of triangle ossificated ligament (α = 25°).
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Yasuhiro FUJIWARA, Takuji KOIKE, Kyoji HOMMA, Michihito AOKI
Article type: Article
Session ID: J0206-4-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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In this study, a three-dimensional finite-element (FE) model of the human ear was established, including the ear canal, middle ear, loading of the cochlea. The acoustic-structure interaction analysis was performed using this coupling model. The impulse-responses of the pressure in the ear canal and the displacement of the stapes were calculated step by step, and the time domain responses were transformed into frequency domain responses by FFT. The general tendency in the frequency response of the each results obtained using the FE model was nearly same as the measurement results. In this way, the measurement of "Otorefrectance" which is a new hearing test was simulated by the analysis using the FE model.
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Yuji TANIMURA, Tomohiro FUKUI, Koji MORINISHI
Article type: Article
Session ID: J0206-5-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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In this paper, it aims to understand blood flows and movements of the red blood cells (RBCs) in microcirculation, so the fluid-solid interactions numerical simulation of unsteady flows was conducted. The two-dimensional incompressible Navier-Stokes equations and equations of motion were solved simultaneously. The artificial compressibility method was used for solving the incompressible Navier-Stokes equations, and the overset method was used to accommodate the movement of the RBCs. A simulation of blood flows between parallel plates was carried out to reproduce blood flows in microcirculation. The results showed that rotation of the RBC was dependent on its initial position. And the wall shear stress was related to not only number of the RBCs but distance between RBC and the parallel plates wall.
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Yusuke UENO, Tomohiro FUKUI, Koji MORINISHI
Article type: Article
Session ID: J0206-5-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The aim of this study is to reproduce the flow phenomena in the circle of Willis by the numerical simulation using lattice Boltzmann method and virtual flux method. We use two-dimensional symmetric model of the circle of Willis. The inlet of this model is set to basilar artery, in which uniform flow is imposed. The outlets of this model are right and left posterior cerebral arteries, right and left middle cerebral arteries, and anterior cerebral artery. This model shows that the mass flow of the inlet is equal to sum of the mass flow at the outlets, and the mass flow at the right side cerebral arteries is the same that at the left side cerebral arteries for its symmetry.
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Tomohiro FUKUI, Koji MORINISHI
Article type: Article
Session ID: J0206-5-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Aortic valve is a membrane that plays an important role in controlling effective outputs of blood flow from the heart. Aortic stenosis is a disease that aortic valves barely open in systole, which cause considerable reduction of amount of blood flow. In this study, we performed numerical simulation of blood flows in a parallel-plate channel with a valve. Lattice Boltzmann method for 2-dimentional 9-velocity (D2Q9) model is used as a governing equation, and virtual-flux methods are applied for a thin valve. The channel length L is 10 times as long as the distance between the parallel-plate D with a grid number of 2002 x 202 on a regular Cartesian coordinate system. The valve moves due to hemodynamic and restitutive forces and separates pressure distribution clearly, which indicates the virtual-flux methods are successfully applied to express a thin valve in a flow.
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Hiroshi YAMADA, Yuuki SHIBAO
Article type: Article
Session ID: J0206-5-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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We carried out finite element analysis to evaluate the deformation, cross sectional area and flow resistance of the capillaries in the skin and fat at a bone prominence when the bone is compressed to the mattress and floor by 200 mN per 1 mm model-thickness. The finite element model consists of skin, fat, bone and mattress or floor. The compressive force is determined so as to obtain the maximum surface pressure of 13 kPa on a contact surface of the mattress. Comparisons of cross sectional area and flow resistance of the capillaries for various degrees of extensibility in the skin, we found that the elasticity of skin had a large influence on the deformation of a capillary in the fat. We also found that the floor caused a significant decrease in cross sectional area and a significant increase in flow resistance under compressions to the floor.
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Daiki SAKAMOTO, Tasuku MIYOSHI
Article type: Article
Session ID: J0207-1-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Our goal is to develop a measurement device that uses a biomarker to detect the user's urinary state continuously and non-invasively. What the secreted biomarker reflects the urinary state is still unclear part. Hence, we first developed a prototype device to detect changes in the concentration of glucose solution through an enzyme sensor. Our prototype device achieved stable measurement of glucose solution continuously for more than eight hours. In the current report, we demonstrate the results of acute changes in the concentration of glucose solution detected by our prototype device.
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Kohhei TANAKA, Jyunichirou FUKUTOMI, Hiroshi TSUKAMOTO
Article type: Article
Session ID: J0207-1-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The characteristics of the blood pump for the extra-corporeal circulation is affected by the resistance of the blood circuit as well as fluctuating in biological circulation. In this study, an extra-corporeal circulation simulator has been developed. This extra-corporeal circulation system can automatically simulate the fluctuating blood pressure and vascular resistance, successively. Moreover, it can change the rotational speed periodically. The steady and unsteady characteristics of this simulator are examined.
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Takuma MIYAMURA, Taiki HARADA, Koji MORI, Naoki TOMA, Takanori SANO, K ...
Article type: Article
Session ID: J0207-1-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Guidewire through blood vessels for medical treatment of cerebral aneurysm used for minimally invasive treatment. Operator observes a position from the outside of body using X-rays imaging method at this time. Therefore, high skill is required when operator insert guidewire in a complicated blood vessel. It is necessary to know the deformation behavior of the guidewire. Guidewire and vessel were modeled with cylindrical segment and rotary spring. The guidewire was pushed in the bend blood vessel. Then the root of guidewire was rotated at a curved part. Following performance and torque transmissibility were evaluated. Following performance of guidewire tip was good. About torsion operation, contact forces distributed nonuniformly, movement of tip was different from operation at hand.
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Minoru MORITA, Mohammad Ajoudanian, Zhongwei JIANG
Article type: Article
Session ID: J0207-1-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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This paper presents the fundamental study on design of a novel micro stirrer for high effective dissolution of cerebral thrombus or blood clot. The actuator is a beam with fixed one side and the other side is free. Under Ultrasonic longitudinal wave excited by piezo-actuator from fixed side, traveling through beam and before reach to tip of beam amount of them impinges to slanted surface some of the energy of the incident longitudinal wave reflected with orientations different from the length direction. The other energy would be converted to shear waves. Despite the elongation and bending at tip, there is no significant bending across other part of beam. The stirrer was evaluated by vertical tip displacement in varied mode shape with using FEM analysis. The obtained results demonstrated that the vertical motion of the stirrer at desired mode shape was less influenced by the length of actuator.
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Takashi Nakagawa, Kazuaki Nagayama, Takeo Matsumoto
Article type: Article
Session ID: J0207-1-5
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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To study cell response to substrate stiffness, we observed shape and migration of UV♀2 cells on polyacrylamide gel substrates with elasticity gradient. The substrates were fabricated with a photopolymerization method and had a soft (E=10 kPa) and a stiff (55 kPa) region connected with a transition region with elasticity gradient of ca. 100 kPa/mm. Cells on the stiff region showed an elongated shape and migrated actively, while those on the soft region were round and seldom migrate. On the transition region, cells tended to migrate toward the stiff region. Cells elongate and attach their pseudopod to substrate when they spread and migrate. The connection between pseudopod and substrate might be too weak on soft substrates to withstand intracellular tension developed during cell spreading and migration. We confirmed that difference of substrate stiffness affects cell behavior.
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Hiroki Kotake, Ryuji Yokokawa, Isaku Kanno, Hidetoshi Kotera
Article type: Article
Session ID: J0207-1-6
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Recently, motor protein such as kinesin or dynein has been used as a nano actuator. Previous works have achieved the control of the movement of microtubules (MT) and the transport of molecular cargo. However, the movement of microtubules was led by minus-end because only kinesin was used as an actuator. In this paper, we patterned motor proteins selectively by surface modification and control the location of microtubules by electrophoresis. Selective patterning of motor proteins and actively control of the MT location enables MTs to move with minus-end and plus-end as leading heads by kinesin and dynein motors.
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Hiroshi TAKAmATSU, Hiroki MATSUSHITA
Article type: Article
Session ID: J0202-1-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Freeze-thaw experiments were conducted with isolated cell suspensions, cells adhered on a glass surface without cell-to-cell interactions, and cell monolayers on a glass surface using human prostate cancer PC-3 cells. No significant difference was found in the rate of intracellular ice formation and the cell survival after a freeze-thaw cycle between suspended cells and adhered cells. However, the cell survival was significantly higher for cell monolayers, in spite of the fact that the rate of intracellular ice formation was also higher significantly. This indicates a potential role of cell-cell adhesion on the freezing process and damage of cells.
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Tetsuhiro OKA, Koichi ITANI, Yoshihiro TAGUCHI, Yuji NAGASAKA
Article type: Article
Session ID: J0202-1-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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We have developed a novel micro optical diffusion sensor (MODS) based on laser-induced dielectrophoresis (LIDEP), which enables high-speed measurement with a small sample volume and on-site sensing of protein conformation. We have developed a novel Micro Fresnel Mirror (MFM) in order to package a DEP cell and an optical component in one chip. MFM consists of two anchored micro slanted mirrors, torsion springs and stiction anchors. The mirrors are slanted when the stiction anchors reached to the substrate and the torsion springs are twisted. We have analyzed the stress of the micro Fresnel mirror by using the finite element method. In this paper, we report the validity of the fabrication of MFM.
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Shigeru TADA, Yuya KITAMORI, Narumi ONODERA
Article type: Article
Session ID: J0202-1-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The present study demonstrated that exposure of cultured bovine aortic endothelial cells (BAEC) to fluid flow resulted in nitric oxide (NO) production and up-regulation of intracellular calcium ion concentration ([Ca^<2+>]_i), monitored by fluorescent dyes of DAF2-DA and Rhod2-DA, respectively using a confocal laser scanning microscope. BAEC were exposed to the pulsatile flow of culture media for 5 minutes. Distribution of NO concentration associated with Ca^<2+> concentration distribution were observed after 5 minutes exposure of the level of 2 Pa shear stress. Results implies that most of the amount of NO was produced by means of Ca^<2+> dependent activation of endothelial nitric oxide syntase (eNOS). Expression of endothelial and inducible NO synthase were evaluated at the protein level. The expression of eNOS in the shear loaded BAEC was detected by the methods of immuno staining (Western Blot) whereas that of iNOS was not confirmed.
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Masako SEKI-SUGIHARA, Takeshi AKINAGA, Tomoaki ITANO, Teruo MATSUZAWA
Article type: Article
Session ID: J0202-1-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Experimental studies have shown that a matrix layer of macromolecules covering the surface of microvessel walls, referred to as the endothelial surface glycocalyx layer (EGL), is negatively charged, and thus, the microvascular permeability to anionic macromolecules is lower than neutral or cationic ones. To investigate the electric charge effect on the material exchange across the microvessel wall, we develop an electrostatic model for the osmotic flow across the EGL when there is a difference in solute concentration. The EGL is modeled as a layer consisting of circular cylinders having a fixed surface charge that are aligned regularly. The expression of the osmotic reflection coefficient is derived for spherical solutes with a fixed surface charge suspended in an electrolyte. The repulsive interaction between the surface charges is found to increase the reflection coefficient. The results suggest that the charge density in the EGL could be about -30 mEq/l.
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Norikazu ISHIMATSU, Masaaki TAMAGAWA
Article type: Article
Session ID: J0202-1-5
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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In this paper, to investigate the effects on shock waves on cells, shock wave propagating into a cell is analyzed by finite element method with one-dimensional viscoelastie wall, and principal stress and shear stress to estimate mechanical stimulus are obtained. The calculation is intended for suspended and attached cell. The result shows that, a high shear stress is caused by the shock wave in the cell membrane, and the frequency and the maximum shear stress is increased when the rise time of the shock wave is small. In addition, effects of membrane of Young's modulus, dumping constant, Poisson's ratio and cell configuration on the maximum shear stress are confirmed.
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Masaki Yamaguchi, Takuzou Iwatsubo
Article type: Article
Session ID: J0202-1-6
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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A super-aging society has led to an increase in number of bedridden elderly and wheelchair users. Because of this, recently the pressure ulcers have become a problem for us. In this research, the causes of pressure ulcers are simulated by cellular automaton method. It is considered that pressure, blood flow, and behavior of cells in the simulation of pressure ulcers. Pressure and blood flow are replaced with oxygen diffusion at each location, and the life of cell is connected by diffusion. Then the result of the simulation and the phenomenon of real pressure ulcers are coinside in the occurrence time of pressure ulcer. So they can be for used in the countermeasure of the pressure ulcers.
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Ryoji MORIYA, Masaaki TAMAGAWA
Article type: Article
Session ID: J0202-1-7
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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This paper describes observations of thrombus formation process on orifice flows by laser sheet and velocity measurements by PIV method in the same circuit. In the observation of thrombus formation process, the brightness of CCD image corresponds to protein or thrombus concentration. In this paper, thrombus formation rate was estimated by the gradient of brightness history near the wall, hi the PIV measurements, shear stress distribution on each orifice was obtained. Comparing the thrombus rate with the shear stress distribution on each orifice, it was found that high shear stress region affects the thrombus rate in the orifice flow.
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Ryo SHIRAKASHI, Kiyohsi TAKANO, Christophe PROVIN, Yasuyuki SAKAI, Ter ...
Article type: Article
Session ID: J0202-2-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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An engineered tissue performing in-vivo physiological metabolic rate should keep cellular density around 10^8〜10^<10> cells/mL, which is far higher than that of normal dish culture. This study proposes a perfusion culture plate with designed microstructure allowing HepG2 cells of 10^7〜10^8 cells/mL to adhere on the plate. The total oxygen metabolic rate of the bioreactor was calculated using the cellular adhesion ratio to fluid shear flow stress and the single cellular oxygen metabolic rate. The measured oxygen metabolic rate is lower than the calculated values, although the trends of oxygen metabolic rate to perfusion flow rate for both measured and calculated are similar. It is suspected that the cellular high oxygen consumption rate in the still medium in the bioreactor might lead to lethal hypoxic condition in a short time before starting the perfusion.
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Akira Iwama, Kazuhiro Ooura, Masanobu UJIHIRA
Article type: Article
Session ID: J0202-2-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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In cryopreservation of tissues or organs, the decision of the optimal freezing condition is difficult because the cell density of the frozen sample, the orientation of the cell, and the form influence cell viability after freezing. Until now, we have found the relative viability decreases by leaving from the cooling area (sample's bottom) with the result of having examined cell viability of human dermal fibroblast monolayer, which imitates the biological tissue, given the freezing direction. In this study, to find the condition to improve the viability decreasing, we examined the concentrated solution and the freezing curve at each part of sample and relationship with the cell viability after cryopreservation. The results showed the possibility that the concentrate of the cryoprotectant solution did not relate to the decrease of viability, and the difference of the cooling rate and the freezing curve in each part of a sample and the change of ice crystal formation with these differences relate to the viability decrease.
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Syuhei HASHIGUCHI, Katsuya NAGAYAMA
Article type: Article
Session ID: J0202-2-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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In order to investigate the cause of arteriosclerosis or thrombosis, research of the flow characteristic of blood attracts attention. In this research, a flow and modification in the micro blood vessel of a fingertip are analyzed using the blood-flow analysis technique by the particle method. Furthermore, the relation between blood fluid and blood vessel modification is studied.
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Tomonori TSUKIYA, Toshihide MIZUNO, Eisuke TATSUMI, Yoshiyuki TAENAKA, ...
Article type: Article
Session ID: J0202-2-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The location of the inflow cannula of the left ventricular assist device (LVAD), which is inserted into the left ventricle at the apex, has a great influence on the flow pattern inside the left ventricle. The design parameters of the inflow cannula have been numerically optimized in order to prevent the thrombus formation in the left ventricle for a prolonged use of the LVAD.
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Fumiya MURANISHI, Yuuya IMAMURA, Tsutomu TAJIKAWA, Kiyoshi BANDO, Kenk ...
Article type: Article
Session ID: J0202-2-5
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Erythrocyte is so flexible that it can pass easily through capillary with deforming. If it can't deform to pass, that causes several diseases. Thus it is very important to evaluate the dynamic deformability of erythrocyte flowing in microcirculation. So in this study, we evaluated to use a micro-channel array which has 5μm×5μm cross-section and 100μm in length on PDMS. From healthy blood, we constructed healthy erythrocyte, which is diluted by a hematocrit of 1% with PBS, hardened one, which is treated with glutaraldehyde, erythrocyte ghost. These suspensions were made to flow through the micro-channels. The motion of each erythrocyte was photographed by using a high-speed video camera. In analysis of these experiments, the shape recovery process of each erythrocyte was modeled by the Kelvin viscoelastic model. As a result of time constant of shape recovery of hardened erythrocyte is shorter than healthy. Erythrocyte ghost of time constant of shape recovery is shorter than healthy.
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Toshinosuke AKUTSU, Akira MATSUMOTO, Kazuhito TAKAHASHI
Article type: Article
Session ID: J0202-2-6
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Three bi-leaflet prostheses, the St. Jude Medical (SJM) and the On-X valves with straight leaflets and the MIRA valves with curved leaflets were tested in the aortic position under pulsatile-flow condition. Dynamic PIV system, which was employed to analyze the flow field affected by the valve-installed orientations, leaflet shapes, and valve designs, and direct measurement of the coronary flow using ultrasonic flow meter were utilized to correlate the results of aortic flow field to coronary flow. Direct measurement of coronary flow clearly shows the increase of flow rate when the circulatory flow inside the sinus of valsalva increase indicating the positive correlation exist between the circulatory flow inside the sinus of valsalva and the coronary flow.
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Yuta NAKAGAWA, Shimpei KOHRI, Tsutomu TAJIKAWA, Atushi SAKURAI, Kiyosh ...
Article type: Article
Session ID: J0202-2-7
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The purpose of this study is to develop covered stent what is able to treat endovascular aneurysm. It was a structural characteristic that thin cover film with stent have microporous. Until now in vivo experiment, increasing the aperture ratio of covered stent from 12.6% to 23.6%, it was possible that coexistence of reliable to embolize the aneurysm and to inhibit the intimal hypertrophy. Furthermore, we expect to form the intima early and to inhibiti of intimal hypertrophy by increasing of aperture ratio. However it is concerned to constrict the thrombus formation. In this study, we investigate the influence on intra-aneurysm flow of varying aperture ratio of multi-pore film by flow visualization of aneurysm model in vitro.
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Masahiro Iikubo, Munemasa John Yamamura, li Li, Shiro Mori, Ikuho Koji ...
Article type: Article
Session ID: J0203-1-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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To clarify the relationship between masseter muscle pain and its edematous changes, we investigated whether increased in thickness and plasma extravasation may occur in the rat masseter muscle as a result of capsaicin injection. In anaesthetized rat, capsaicin solution was injected into a masseter muscle on the one side, and vehicle into one on the other side. The thickness of the masseter muscle was measured by means of high-frequency ultrasound. Plasma extravasation was determined by means of the Evans blue dye method. As results, capsaicin injection into the masseter muscle induced thickening and plasma extravasation in the masseter muscle, and combination with local anaestesia counteracted the dye extravasation, indicating neurogenic inflammation change in rat masseter muscle.
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Yu NAKAMICHI, Souichi SAEKI, Takafumi HIRO, Masunori MATSUZAKI
Article type: Article
Session ID: J0203-1-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The endoscopic Optical Coherence Tomography (OCT) has been developed for 3-dimensional detection of early cancer with microscale. Nevertheless, it is difficult to detect cancerous tissue due to complicated speckle patterns contributed by optical properties of scattering and absorption in OCT images. Previously, we proposed a visualizing technique of drug distribution, namely 2-Color Optical Coherence Dosigraphy (2C-OCD), which was based on 2-Color OCTs having different optical absorbance of DDS drug. In this study, an in vivo tomographically diagnosing technique of early cancer is presented, in which 2C-OCD is applied to cancerous tissue with selective uptake of DDS drug. The feasibility study was demonstrated and investigated, by means of 2C-OCD visualization of the subcutaneous tumor- implanted nude mice with DDS drug AlPcS administered. Consequently, it was confirmed that 2C-OCD could diagnose tumor tissue with sensitivity 82.5% and specificity 78.3%, respectively. Therefore, 2C-OCD can detect DDS drug distribution in cancerous tissue, thus has a promising modality for in vivo tomographically diagnosing technique of early cancer.
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Rui CHEN, Li LI, Yukiko WATANABE, Nicolas SAX, Sachiko HOREI, Shiro MO ...
Article type: Article
Session ID: J0203-1-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Three-dimensional high-frequency ultrasound (HF-US) combined with nanobubbles (NBs) permit detection of vessels in tumor. Description of the vessel density in tumors has recently been used for differentiating benign from malignant disease, but it was rarely reported in detection of liver metastases. In this study, we aimed to evaluate the possibility of detecting liver metastases at a minimum size, by evaluation the vessel density in the preclinical liver metastatic models with three-dimensional HF-US and NBs longitudinally. Tumor cells with luciferase-expressing were injected into the spleen slowly to establish the liver metastases models. Liver metastases were confirmed by luciferase activity located in the mouse liver area which was measured by in vivo bioluminescence system (IVIS). Ultrasound imaging on mice livers was performed by a high-frequency ultrasound system after NBs were administered from the tail vein. Vessels in the liver were constructed and the vessel density in the whole liver was calculated by the contrast mode soft. Contrast ultrasound images showed the change of vessels in normal and metastatic parts of liver with time. Vessel density could used to compare the angiogenesis in the metastatic mouse liver with the normal livers. These results demonstrated a system of HF-US combined with NBs could be useful for detection of liver metastases at a minimum size by evaluation the vessel density.
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Hidetake YAMAMOTO, Hideki GOKO, Masaya GOTO, Yuta KONNO, Nao SUZUKI, H ...
Article type: Article
Session ID: J0203-1-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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This research purpose is to develop minimal medical units applying heated actuations of the Shape Memory Alloy (SMA) transducers using the medical Ti-Ni, in order to enable minimal hypodermic invasive microvolume blood suction or drug delivery by equipping nontoxic and minimal edged microneedle to be created in our laboratory. We focused on lymphocytes for immunotoxin and erythrocytes for glucose level in blood. In the last year paper, we had already reported that the joule heating of the earlier SMA multi-transducer unit might be useful for indenting blood vessels because they whose outer diameter was larger than that of the needle lay in 2 mm deep from surface skin. Therefore, this paper reported the improved mechanisms of the unit and its actuations by low DC inputs. As for the actuation of multi-face foil transducer for blood suction, when applying DC 1.5 V and 2 A, the foil transducer recovered as plane state as before multi-face forming in room temperature. The foil transducer started actuation 4.4 s later from start of heating, recovered plane state 8.3 s later more.
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Yousuke SAKO, Hidenori YOSHIMURA, Yutaka MIHARA, Masaki ISHIBASHI, Hid ...
Article type: Article
Session ID: J0203-1-5
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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A fabrication method of a painless transdermal micro needle array is proposed to realize its inexpensive and mass production. In order to avoid a risk by breakage of the needle when the needle is penetrated into the epidermis, the array is made with biodegradable polymer, for example, PLA. The proposed method has the following processes, (1) a mold dies having many micro through-holes is heated over the melting point of PLA, (2) the heated mold comes into contact with surface of the PLA plate, (3) the melted PLA is poured into the through-holes, and (4) the formed PLA plate is cooled to less than the melting point and removed from the dies. It is difficult to fabricate the array device because of the ratio of needle height to the diameter is large. So, heating temperature, time of heating the plate, moving stroke of dies and demolding temperature were examined and then fabrication of high precision circular cylindrical shaped needle array became possible.
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Shunichi SATO, Ken YOSHIDA, Mitsuhiro TERAKAWA, Hiroshi ASHIDA
Article type: Article
Session ID: J0203-2-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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In this study, we examined the use of photomechanical waves (PMWs) to transiently enhance the permeability of blood vessels for drug delivery to target tissues. PMWs were generated by irradiating a laser target (a rubber disk covered with a transparent plastic sheet) with 532-nm, nanosecond laser pulses; a laser target was placed on target tissue. As a test drug, Evans Blue (EB) was injected into a tail vein of a rat, and thereafter PMWs were applied to the dorsal skin, tibial muscle and brain. For brain, a cranial window was made. After perfusion fixation, distributions of fluorescence originating from EB in tissues were analyzed by fluorescence microscopy. The fluorescence was observed in the extravascular spaces in all tissues exposed to PMWs, and in addition, EB molecules were found to be introduced to cells in the tissues. In most cases, tissue damage was not observed. These results demonstrate the capability of PMWs for transvascular drug delivery to target tissue.
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Noriyoshi TERAMOTO
Article type: Article
Session ID: J0203-2-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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The combination of ultrasound and nano-bubbles coated with lipid bilayers (i.e. hybrid nano-bubbles) induces transient membrane permeability, leading to direct delivery of exogenous molecules (such as plasmid, siRNA, anticancer drugs etc.) into cells with minimal invasion (i.e. sonoporation technique). When Kir6.2 genes have transfected into native smooth muscle layers of mouse aorta by use of sonoporation, RT-PCR analysis revealed the expression of Kir6.2 transcripts in vascular smooth muscle. When Kir6.2 genes, tagging with Myc-genes, were transfected into native smooth muscle layers using sonoporation, immunohistochemical studies have revealed that Kir6.2 and Myc proteins were co-expressed in vascular smooth muscle cells. The phenylephrine-induced contraction of mouse aorta was significantly reduced after the treatment of Kir6.2 gene-sonoporation, hyperpolaring the membrane potentials. These results suggest that Kir6.2 genes were functionally expressed in mouse vascular smooth muscles, causing a vascular relaxation due to the activity of Kir6.2.
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Nicolas SAX, Sachiko HORIE, Yukiko WATANABE, Yoko YAGISHITA, Rui CHEN, ...
Article type: Article
Session ID: J0203-2-3
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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Newly formed tumor vasculature is usually abnormally leaky due to the extensive angiogenesis induced by the growing tumor, which enables extravasation of particles with a diameter of less than 200 nm: this phenomenon is recognized as the enhanced permeability and retention (EPR) effect. Due to their versatility, liposomes are potential candidates to take advantage of the EPR effect and passively target tumor cells. In this study, liposomes encapsulating fluorescent dye or bearing covalently-bound fluorophores on their surface were prepared and characterized in vitro. DLS and fluorescence measurements respectively showed that they currently display a diameter of less than 200nm and a fluorescence intensity similar to that of commercially available agents. Further research aims at an in vivo observation of the EPR effect through real-time visualization of the accumulation of such liposomes.
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Kosuke MATSUMURA, Masaki TAMAGAWA
Article type: Article
Session ID: J0203-2-4
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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This paper describes the development of microcapsules for shock wave drug delivery systems (DDS) by using chemotaxis. Especially, we check cytokine concentration gradient, which was obtained in our experiment, on neutrophil's membrane by numerical simulation for elucidating the mechanism of neutrophil's motion. As a result, the concentration gradient changes from negative value to positive by changing diffusion coefficient and adsorption-desorption coefficient of neutrophil's membrane. This result shows same trend as that in our previous experimental result.
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Masaaki TAMAGAWA, Michiaki OKI
Article type: Article
Session ID: J0203-2-5
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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This paper describes the fundamental investigations for developing new technology using shock waves and bubbles, such as drug delivery systems (DDS). To understand the fundamental phenomena, deformation process of a bubble in a microcapsule is observed by pressure waves to analyze the behavior of the bubble collapsing in the microcapsule. It is found that by selecting the proper parameters, there are possibilities to make the large deformation of bubble to disintegrate.
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Yukio TOMITA, Ryuichiro MINAGAWA, Bungo SHIMOMURA, Tetsuya KODAMA
Article type: Article
Session ID: J0203-2-6
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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For destroying Sonazoid microbubbles 1 MHz - ultrasound waves was irradiated by employing a concave ultrasound probe with the vibrating diameter of 40 mm and the arithmetic focal length of 80 mm. The probe was set in distilled water at temperature of 25 ℃. A suspension of Sonazoid ultrasound contrast agent diluted with distilled water with the volumetric concentration of 5 % [v/v] was shut in a cuvette which was positioned at x_<c,b> measured from the bottom of the ultrasound probe. It was found that Sonazoid microbubbles were rapidly destroyed and the survival number was reduced to 40 % of the original number at the exposure time of 100 ms. When a cuvette containing suspension of Sonazoid microbubbles was set at the arithmetic focal point, a limited volume of Sonazoid suspension was exposed to the ultrasound waves, resulting in a relatively larger survival number of Sonazoid microbubbles. Sonazoid destruction was observed by taking snapshots using a nano-pulse light with the pulse duration of 180 ns as a light source.
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Terumasa NARUKAWA, Hidekazu NISHIMURA
Article type: Article
Session ID: J0201-1-1
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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This paper investigates occupant injury protection in frontal car crash. The occupant is modeled as three lumped masses. An active shoulder belt and an active lap belt are used to control occupant's motion. We assume that the shoulder belt force acting on the torso is controlled by the active shoulder belt, and that the lap belt force acting on the pelvis is controlled by the active lap belt. The control problem is formulated as an optimization problem. Numerical simulations show that the cooperative control of the active shoulder belt and the active lap belt reduces the maximum deceleration of the torso.
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Kouichi OOTA, Hiroshige NAGUMO, Tomosaburo OKABE
Article type: Article
Session ID: J0201-1-2
Published: September 04, 2010
Released on J-STAGE: August 01, 2017
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In the near future the judgement of the timing just before frontal crash when the imminent crash is unavoidable would become technically viable by rapidly-developing active safety technology with some advanced vehicle surrounding sensing function. The research objective is to carry out a feasibility study on a new front seat related passive safety technology to reduce front seat occupant chest injury risk substantially which is activated during a pre-crash phase based on such trigger information.
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