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Yuya SUZUKI, Hiroyuki FURUKAWA
Article type: Article
Session ID: J0104-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In previous studies of a flow caused by a rotating disk in a causing, the geometry of a rotating disk is not considered significantly. Recent studies unveil that a gap of radius direction has an great influence on a flow between a casing base and rotating disks. In this study, we used some kind of rotating disks, and investigate about the influence of a radius direction gap to a flow near the fixed disk. As a result, we confirm that the difference of disk geometries cause different "Front angle" in each disks. Our experimental study analyze "Front angle" in detail.
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Takashi WATANABE, Hiroyuki FURUKAWA
Article type: Article
Session ID: J0104-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In this paper, the transition criterion of the periodic spiral rolls to the turbulent spirals found around a rotating disk in a cylindrical finite enclosure is considered. The flow on a rotating disk has some patterns consisted of circular flows, spiral rolls, turbulent spirals and spot flows. We adopt some methods using the flow structures, embedded diagrams of the velocity components, correlations between fluctuating velocity components, and present their results found during the transition from the spiral rolls to turbulent spirals. Each method shows its characteristic and usefulness to estimate the threshold at the onset of the breakdown of the spiral rolls.
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Tetsuya CHIBA, Yuriko TAKESHIMA, Takashi TOKUMASU, Issei FUJISHIRO
Article type: Article
Session ID: J0104-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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When visualizing large-scale particle systems, it is difficult to maintain adequate framerates because we have to render dynamic scenes with a large amount of small spheres. In this article, we propose a time-critical rendering (TCR) scheme which uses a high-quality, implicit surface method in combination with a fast method based on shaded texture mapping. In our scheme, the method for rendering each of the particles is determined on the fly with reference to the distance between the center of the particle and the base point defined as the viewpoint or gaze. In order to apply the TCR scheme to walkthrough animation, a threshold used for switching the two rendering methods is dynamically changed for the actual framerates to fit into a prespecified closed interval. We used a molecular dynamics simulation dataset to empirically evaluate the effectiveness of our TCR scheme.
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Yuta OISO, Atsushi SAKURAI, Kiyoshi BANDOU, Kenkichi OHBA
Article type: Article
Session ID: J0201-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The microcapsules for medical application such as the drug carrier in the Drug Delivery System and the simulated red blood cell in the model blood in vitro are actively researched. In this study, we produced the microcapsule with three-layer thin film of alginate-poly-L-lysine-alginate based on alginate gel particles. We examined the membrane thickness and elastic property. As a result, increase of incubation time with poly-L-lysine induces increase of the membrane thickness and the elasticity of the microcapsule.
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Kosuke MATSUMURA, Masaaki TAMAGAWA, Yoshinori FURUKAWA
Article type: Article
Session ID: J0201-1-2
Published: September 12, 2009
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 neutrophil's motion mechanism. As a result, the concentration gradient changes from negative to positive by changing diffusion coefficient and adsorption-desorption coefficient of neutrophil's membrane. This result has show trend as that in our previous experiment result.
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Sachiko HORIE, Yukiko WATANABE, Rui CHEN, Li LI, Shiro MORI, Tetsuya K ...
Article type: Article
Session ID: J0201-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Seventy percent of patients with bladder cancer present superficial tumors with high recurrence rate. In order to develop effective superficial bladder cancer gene therapy, effective gene delivery using nanobubbles (NBs) and ultrasound (US) is our ultimate goal. To achieve this goal, we propose localized gene delivery in bladder using NBs and low-high-intensity US (LHUS) while low-intensity US direct NBs proximate to targeted cells in the bladder and high-intensity US collapse NBs to increase cell membrane permeability resulting the entry of exogenouse molecules into proximate cells. In the present study, to demonstrate the effectiveness of NBs and LHUS to localize the gene delivery to a designated bladder wall, we have assessed: i) in vivo local delivery and fragmentation of NBs with high frequency US imaging system; ii) localized molecular delivery of fluorescent molecules and quantification of the transfection efficacy; and iii) transfection of plasmid DNA and quantification of the transfection efficacy.
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Akihito SAYOU, Maya IRIE, Kazumichi KOBAYASHI, Hiroyuki TAKAHIRA
Article type: Article
Session ID: J0201-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The growth and shrinkage of surfactant-coated microbubbles are observed with a high-speed video camera. The observed bubble motion is compared with the simulation in which the dynamic surface tension and the variation of gas permeation resistance of surfactant layers are considered. The simulation is in good agreement with the experiment. It is shown that when the microbubble grows under pressure reduction, the gas diffusion from the surrounding liquid to bubble inside is suppressed by the increase of the surface tension, while it is promoted by the decrease of the gas permeation resistance. On the other hand, the bubble shrinkage due to gas diffusion after pressure increase is strongly affected by the increase of the gas permeation resistance. The variations of both the surface tension and the gas permeation resistance determine the diffusion process of microbubbles.
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Yoichi FUJIMURA, Takeru YANO
Article type: Article
Session ID: J0201-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The nonlinear dynamics of a spherical gas bubble in a liquid water is reconsidered on the basis of the Rayleigh-Plesset equation and kinetic theory of gases. If the bubble diameter is comparable to or smaller than the mean free path of gas molecules in the bubble, we need to consider the nonequilibrium effect of the gas. Then, the gas behavior is governed by the Boltzmann equation, and the Rayleigh-Plesset equation is extended to describe the nonequilibrium effect. In the present study, we assume that the bubble is filled with the vapor of the surrounding liquid, and analyze the nonequilibrium phenomena including the evaporation and condensation at the vapor-liquid interface for the case that the vapor is the free molecular gas and the boundary condition at the interface is the complete condensation condition.
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Ryosuke IMAI, Hiroya NAKAGAWA, Kousuke SAKURAI, Masao WATANABE, Shigeo ...
Article type: Article
Session ID: J0201-1-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In the field of medical engineering, the application of bubbles of nanometer size to Drug Delivery System (DDS) has attracted great attention as the administration of next generation. DDS with bubbles is expected to be a noninvasive clinical treatment. As the transport carrier of DDS, there exists bubble encapsulated in a lipid bilayer, generally called as a lipid bubble. However, dynamic properties of these lipid bubbles are not yet made clear. In this study, acoustic characteristics of lipid bubbles are experimentally investigated. The resonant frequencies of lipid bubbles are evaluated from attenuation of ultrasound pulse propagating through the experimental cell filled with lipid bubble solution. It is found that the attenuation spectrum has two dominant peaks in the frequency range of 1.0 through 14.0 MHz due to the acoustic energy absorbed by lipid bubble with resonant oscillations.
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Hidenori YOSHIMURA, Tatsunori OKAMOTO, Hidetoshi HAMAMOTO, Masaki ISHI ...
Article type: Article
Session ID: J0201-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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A new fabrication method of a painless micro needle array for high reliable vaccine delivery system through a epidermis is proposed. This method has been developed to realize the inexpensive and mass production of the needle array. For safety against the break of the needle, the needle is made with biogradable polymer (PLA). The proposed method has the following processes, (1) Si tool in a shape of micro needle array is heated, (2) tops of the needles over the Si tool are touched onto the surface of the polymer plate to melt the contacting areas, and (3) the Si tool is detached from the plate to form the needles by elongating the melted polymer. In order to make the uniform needles over the plate, temperature, touching time, and withdrawing speed of the Si tool and tolerance of the polymer plate are examined. By the optimized working conditions, keen corn-type needles having the height of about 500μm can be formed enable to penetrate into the epidermis.
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Yuta NAKASHIMA, Koji OKAMOTO, Takashi YASUDA
Article type: Article
Session ID: J0201-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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This paper presents the fabrication and testing of a microfluidic device consisting of a chamber for cell culture, a microhole array for chemical release, and a microchannel for sheathflow generation. The microholes of 2 μm in diameter were opened in the 100 nm thick SiN membrane of the culture chamber bottom using photolithography and CF_4 plasma etching. The microchannel having three inlets was located directly under the culture chamber. Experiments using a fluorescent solution showed that chemical release through the microholes was successfully controlled by regulating flow rates of three fluids which form the sheathflow. This result suggests that the fabricated device can be used for temporal-spatial control of localized chemical stimulation to a cultured cell.
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Masami KAGAYA, Yasuhiro SATO, Yoichi AKAGAMI
Article type: Article
Session ID: J0201-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Authors have been developed a novel noncontact stirring method of slight amount DNA contents droplet. We have confirmed that the stir of the μL order droplet has not progressed easily by the conventional shaking machine, and short processing time of DNA hybridization is difficult. Therefore, we tried a new method. This droplet shows active motion between electrodes under high voltage AC. electric field. We have proposed new stirring method for slight amount DNA contents droplet. Then we have obtained good result at the stir time of 1/3 of the method.
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Souichi SAEKI, Takanori Nishino, Takashi SAITO
Article type: Article
Session ID: J0201-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Recently, the biomedical tomographic diagnosis using near-infrared fluorescence, which is based on the inverse analysis, has been being highly improved to apply molecular biological techniques to DDS. In this study, a novel photo-dynamic diagnosis system was constructed as "Near-Infrared Photo-Dynamic Computed Diagnosis" (NIR-PDCT). Two excitation lights and a CCD detector are symmetrically located at the same side to object, i.e. reflection-type illumination, taking account of clinical applications. This system provides fluorescence tomographic images from multi-directionally captured intensity distributions emitted from object surface, based on convolution back-projection. In this system, proposed was a 2-dimensional deconvolution technique using directional-splitting shift-variant point spread function (PSF), in order to restore the tomographic image blurred by the light scattering effect having biological tissue. Experimental verification was carried out quantitatively using a bio-phantom embedding single tube of DDS agent AIPcS. Consequently, it was found to be easier to identify a fluorophore, suppressing light scattering degradation by PDCT, and recover fluorophore information, e.g. position and concentration.
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Rui CHEN, Yukiko WATANABE, Sachiko HOREI, Shiro MORI, Manabu FUKUMOTO, ...
Article type: Article
Session ID: J0201-2-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Preclinical mouse models are essential to the study of liver metastasis, yet their utility has been limited by difficulty in tracking the progression of metastases through time. In this study, we attempted to applicate some non-invasive methods to study the murine liver metastasis. Livers of mice were observed by camera system termed photo dynamic eye (PDE) with the indocianine green (ICG) injected into the tail vein. Mice received and intrasplenic injection of luciferase-expressing tumor cells. Luciferase activity was measured by in vivo bioluminescence system (IVIS). Ultrasound imaging was performed by a high-frequency ultrasound system (VEVO), after nanobubbles were administered from the tail vein. As the result, murine liver metastases were identified using PDE and IVIS. Two-dimensional and three dimensional images by ultrasound and nanobubbles showed vessels in the liver. These results could be benefit for early diagnosis of liver metastases with a minimum detection size in preclinical model.
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Suguru YOSHIKAWA, Yusuke TAHARA, Masaki YAMAGACHI
Article type: Article
Session ID: J0201-3-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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As a key biomarker of the individual stress response, cortisol is the increasing focus of psychobiological stress research. The ability to provide real-time scan of cortisol levels will open up substantial new possibilities. We describe an immuno-chromatographic technique allows point-of-use measurement of cortisol (CORT) manifesting in readily accessible human saliva. A disposable test-strip serves as the biosensing platform for salivary CORT. In order to realize the test-strip, we synthesized a glucose oxidase (GOD)-CORT conjugate. Introducing a saliva sample onto the collection pad produces a red band after 20 minutes. The reflectance of the band is measured by an optical analyzer and the CORT concentration calculated by using a calibration curve (R^2 = 0.945). The sensitivity of our test-strip (1 ng/ml) is adequate to analyze human salivary CORT.
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Tomoki SHIMAKURA, Akira DATE, Masaki YAMAGUCHI
Article type: Article
Session ID: J0201-3-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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When skin is exposed to ultraviolet (UV) light consisting of UVA (320-400nm) and UVB (290-320nm) on the earth. reactive oxygen species (ROS) as well as lipid peroxides and their radicals are formed. It is well documented that these free radicals and ROS cause oxidative cellular stress, cell injury and DNA damage in the epidermis, and eventually induce inflammation, skin photo-aging, photo-toxicity, or malignant tumors. To protect skin from these radical species, there is a multiple natural defense mechanism in the skin. For instance, anti-oxidant enzymes such as superoxide dismutase (SOD). catalase (CAT), and glutathione peroxidase (GSH-Px) play important roles on protecting the skin against degenerative changes by free radicals or ROS. The purpose of this research is to develop an analysis method of CAT, in skin noninvasively by using a test paper. A TIVIBZ was selected as the chromogenic substrate for detecting the catalase activity. The catalase activity ranged between 0 and 4.0 U/ml by using the test paper fabricated. The CVs showed comparatively low level between 2.15 and 2.28 %. It was suggested that the test paper might be used for the quantitative analysis of catalase activity in the stratum comeum.
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Wataru Suzuki, Akira DATE, Masaki YAMAGUCHI
Article type: Article
Session ID: J0201-3-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Although the number of the patients with skin cancer has increased every year. noninvasive diagnosis methods of skin cancer have not been established yet. It is reported that Catehpsin L (CatL) correlated with actinic keratosis and squamous cell cancer. In this study, an novel immuno-chromatographic test-strip is proposed for Cad, analysis in skin. The fabricated test-strip consists of four pads, a sample pad. a conjugate pad, a nitrocellulose membrane and a absorption pad. After dropping a sample. it required 90 seconds to reach the solution at the test line on the test-strip and indicated a red colored band 3 minutes later. We proposed that this newly developed immuno-chromatographic test-strip has a highly potential as a tool for early diagnosis of skin cancer.
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Daisuke ISHIHARA, Yu YAMASHITA, Shotaro YOSHIDA, Tomoyoshi HORIE, Tomo ...
Article type: Article
Session ID: J0202-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In this study, we evaluated the lift force generated by the crane-fly's flapping wing with the passive pitching using the dynamically scaled model. Since the wing and the surrounding fluid interact with each other, the dynamic similarity between the model and actual crane-fly flights was measured using not only the Reynolds and Strouhal numbers but also the mass and Cauchy numbers. Although there existed the difference between the mass number due to the limitation of available solid materials, but the lift coefficient simulated by our model indicated that the flapping wing with the passive pitching produces the enough lift force to support the crane-fly's weight.
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Takayoshi IDA, Ken-ichi TSUBOTA, Hao LIU
Article type: Article
Session ID: J0202-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In the last decade, desired to be capable of performing missions such environmental monitoring, surveillance, and assessment in hostile environments MAVs have become a rapidly increasing hot topic. MAVs have a maximal dimension of 15 cm and nominal flight speeds of round 10 m/s, which are comparable with natural flyers of birds. bats and insects in size. Flapping flight of birds and insects often shows fascination aerodynamic performance in terms of acceleration and quick turning even in dust and is the main subject till now. However, there are still very few studies associated with the flapping-wing control system. In this project, I am aiming at building up an ornithopter with an integrated control system containing posture sensors, GPS, and microcomputer, etc and hope to establish a specific autonomy flight control system for flapping-wing MAVs.
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Kazuhiro Yanaoka, Ken-ichi Tsubota, Hao Liu
Article type: Article
Session ID: J0202-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Insect flapping flight can offer some novel mechanisms useful in designing MAVs (Micro Air Vehicles), a flyer with a maximal dimension of 15 cm. There have been many fascinating works done on the biological flights of moth, fly, bee and so forth in the last decade, but still very few is found about butterflies. Butterflies have low aspect-ratio wings and low wing beat frequencies, but in general exhibit apparently pitching oscillations vertically during flapping flight. Additionally, they change the wing areas during flapping flight, which is called wing-morphing. In this study, aiming at providing a comprehensive study on aerodynamic mechanisms in butterfly flights we have carried out a CFD-based numerical simulation of flapping flight in butterfly on a basis of realistic wing-body geometry and wing kinematics.
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Yoshiaki TANAKA, Akinori SATO, Kennichi TSUBOTA, Hao LIU
Article type: Article
Session ID: J0202-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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We have developed an insect-size X-wing flapping Micro Air Vehicle (MAV) with a body-length of approximately 6 cm. To quantify the aerodynamic performance of the MAV with a specific focus on the clap and fling mechanism we measured the thrust/lift forces in tethered and free (level) flights. Our tethered flight results show that the MAV is capable to create a thrust force 1.3 times greater than its weight. In the free (level) flight, the stroke plane angle is observed to be around 45 degrees corresponding with a flapping frequency of approximately 25 Hz. Furthermore, we find that the MAV is able to perform the level flight when a static thrust produced is over 0.8 times its weight and that appropriate flexibility of the wing can be a crucial factor in affecting the thrust production to keep it stay on airborne.
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Tatsuya NII, Akiyosi IIDA
Article type: Article
Session ID: J0202-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In order to develop Micro Air Vehicles (MAV) for an explorer in disaster area, mechanical flapper based on insects' flight was developed. Aerodynamic forces and flapping motions were measured and compared to that of insects. The experimental results showed the flapping amplitude and feathering angle of the mechanical flapper were almost the same as that of real insects. The aerodynamic forces depended on the phase difference of forewing and hind wings. The maximum aerodynamic force can be obtained at the phase difference between forewing and hindwing is almost 0 degree. Moreover, the coefficient of energy becomes the minimum at this phase difference. The developed mechanical flapper generates aerodynamic lifting force which is enough to lift real insects.
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Hidetoshi TAKAHASHI, Kiyoshi MATSUMOTO, Isao SHIMOYAMA
Article type: Article
Session ID: J0202-1-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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An insect generates differential pressure between the upper and lower surface of its wings by flapping motion. The insect flies by utilizing that pressure difference as aerodynamic force. In the present study, a high-sensitive sensor utilizing MEMS technology was fabricated to measure the differential pressure. A piezoresistance cantilever was used as the differential pressure sensor. The size of the sensor was 1.5 × 1.5 × 0.3 mm^3, which was small enough not to interfere with the wings under flapping state. The measurement range and resolution were 100 Pa and 0.1 Pa, respectively. By fixing the sensors to an artificial insect wing surface, we demonstrated that the differential pressure distribution was enabled to measure.
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Tonau NAKAI, Kota AOKI, Takafumi MAIGUMA, Tomonobu GOTO
Article type: Article
Session ID: J0202-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Bacterial motion near a free and rigid surface is numerically investigated by use of the boundary element method. The fluid flow around a bacterial cell is approximated as a creeping flow. The swimming speed and the rotational rate as functions of pitch angle and distance from a surface are calculated for a bacterial model with a single flagellum. Swimming speed and yaw rate near a free surface was found to be quite different from the motion near a rigid surface which had been previously analyzed. Time-varying pitch angle and distance from the surface are also analyzed near a rigid surface. The result indicates that a bacterium can swim for a long time near the surface without collision.
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Yusuke Inui, Naoki Ono
Article type: Article
Session ID: J0202-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Micobe can move smoothly in water environment with high efficiency, which could offer new ideas for future micro machines. In this study, we investigated the spiral moving behavior of flagellum by using numerical and experimental models. We simulated euglena's fluid environment of Re number of 10^<-4>. The optimal roll number of the spiral shapes in terms of flow velocity and driven force was studied and the existence of most efficient roll number was suggested.
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Takuji Ishikawa, K. Drescher, K. Leptos, T. J. Pedley, R. E. Goldstein
Article type: Article
Session ID: J0202-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Hirotomo HISAMA, Akitoshi ITOH
Article type: Article
Session ID: J0202-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The authors have been developing the micro manipulation system using motion controlled microorganisms. Paramecium was used as a manipulator. Motion control was done by applying the negative galvano-taxis. Since the Paramecium's head is smooth round shape, it is difficult to transduce its force to the object effectively. Therefore, an attachment device for an operation tool of Paramecium has been developed. The authors have succeeded to attach an operational tool to the paramecium. It made the object transportation easier. The attachment of operation tool, however, was very difficult and the transportation experiment with operational tool have not reproduced during 3 years. Based on these results, a string type operation tool have been developed in this study. The string construction make the soft wearing comfortableness for paramecium. Several types of the operation tool were examined. To do these types of the operation tool practical one, it is needed to develop more weight shaving and simplification of the construction method.
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Kenji KIKUCHI, Osamu MOCHIZUKI
Article type: Article
Session ID: J0202-2-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The purpose of our study is to analyze swimming motion of a mosquito larva which is well called as a wriggler. When it meets some dangerous situations, it escapes actively from air-water surface to bottom with rapid swimming motion. A swimming thrust is obtained by a paddling motion of its tail fin with a separation of a vortex in the power stroke. We measured velocity vector fields around the body and wake by micro PIV measurements. It was found that a snapping motion of its tail fin yielded thrust.
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Yohei KATSUMATA, Ken-ichi TSUBOTA, Hao LIU
Article type: Article
Session ID: J0202-3-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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A numerical study of hydrodynamics and maneuverability of Zebra fish free swimming is presented. Unsteady hydrodynamics around an undulatory swimming body is solved using an integrated modeling method combining a 3D Computational Fluid Dynamics (CFD) method and a Computational Swimming Dynamics (CSD) method. A larva fish, zebrafish and Danio rerio is modeled, which "swims" by sending a laterally compressing, sinusoidal wave down the tail tip. Hydrodynamics of the 3D larva fish model in terms of the burst, the cyclic and the coast swimming modes were then analyzed and compared with experimental data. Our results present a sequence of 3D vortex structures in free swimming and its relationship with the swimming maneuverability of zebra fishes. This provides a general understanding of the relationship between the dynamic vortex flow and the energetic in terms of output power associated with the undulatory locomotion of vertebrates.
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Taketoshi SUZUKI, Akihisa KONNO, Koichi HIRATA, Yoichi NIKI, Masakuni ...
Article type: Article
Session ID: J0202-3-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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We develop a fishlike underwater vehicle that controls body orientation (pitching angle of the body) using motion of internal weight. We intend that, by controlling body angle and thrusting toward the direction of the body axis, the vehicle will perform quicker up/down swimming. We develop a weight positioning system for the vehicle; the internal weight moves not only laterally but also longitudinally so that larger pitching angle is obtained. The vehicle is 700 mm in length, and with the motion of 900 g weight in ± 75 mm in lateral and 30 mm in longitudinal, this vehicle inclines 45 degrees within 5 seconds. Theoretical estimation of body angle with the motion of center of gravity is also discussed.
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Satoshi TERADA, Akihisa KONNO, Koichi HIRATA, Yoichi NIKI, Masakuni KA ...
Article type: Article
Session ID: J0202-3-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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To accurately control depth of underwater vehicle in rather shallow water (around 1 m), we develop an underwater machine with a buoyancy control unit, and investigate methods to control depth of the machine. This machine is 1.9 kg in mass, and has a buoyancy control unit (piston) that control range is ± 29.45 cc. Experimental results show that the depth of the machine can be stabilized when time of piston shrinkage and extension is both 3 sec. and, after that, piston is extended ('overshoot') in 1.25 sec. We also conduct numerical simulations of motion of the machine, and these results show that the depth can be stabilized when overshoot time is 1.57 sec. Effects of the control line (cable) and fluid force against the machine are discussed.
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Hideaki FURUKAWA, Akihisa KONNO, Koichi HIRATA, Yoichi NIKI, Masakuni ...
Article type: Article
Session ID: J0202-3-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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To realize quick-turning motion of an underwater vehicle, we calculate swimming and turning motion of a model underwater vehicle. We also develop an underwater machine with 2-DoF. Results of the calculation show that the model machine has propulsive force enough to go straight at 1m/s, and that can turn to 180 deg in less than 0.5 s. On the other hand, result of experiment is by far slower than that of model calculation. The machine velocity is around 0.12 m/s and it turns to 80 deg in about 2 s. Causes of the difference are discussed, such as lack of treatment of vibration of the body.
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Qilong SUN, Hirohisa MORIKAWA, Shunichi KOBAYASHI, Motomu NAKASHIMA, H ...
Article type: Article
Session ID: J0202-3-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Dolphins are characterized as a high speed swimmer. Tail flukes of a dolphin have been considered to play an important role as a principal propulsor in its high speed swimming. In this paper, we focused on the inner structure of the tail flukes and the mechanical properties of the tail flukes. The mechanical properties of two connective tissues were investigated by a tensile test and a compression test by using a hand-made testing apparatus. The result could be useful in improvement of artificial flukes for the disabled dolphin which lost her tail flukes.
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Keiko AKIYAMA, Motomu NAKASHIMA, Tasuku MIYOSHI
Article type: Article
Session ID: J0202-3-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The objective of this study was to develop the widely useable simulator for optimization of walking form in water. The simulator consists of two calculation parts, calculation part for joint torque and calculation part of muscle force. In the simulation, joint angles are set as design parameters, and joint torque and muscle force are calculated repeatedly until the objective function becomes the maximum value. By using this simulator, the optimal walking form in water for elderly people was calculated as example. From the optimization, it was found that the form, in which knee joint is actively used, becomes the optimal form for elderly people.
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Jiro SAKAMOTO, Kentaro ARIHARA, Takeshi YAMAZAKI
Article type: Article
Session ID: J0202-4-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Musculoskeletal structure of the giraffe's long and heavy neck must be subjected to large moments and forces, and in spite of this, giraffes can swing their necks in a highly flexible manner. Mechanical adaptation is expected on musculoskeletal structure of giraffe's neck. Several anatomical studies of musculoskeletal system of giraffe's neck have been reported, however; to-date there has been no biomechanical studies. The purpose of this study was to evaluate the mechanical strength of giraffe's neck and to consider its mechanical adaptation. We analyzed stress distribution of the cervical vertebrae by finite-element method and evaluated their strength and mechanical adaptations.
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Nobutaka MAEZAKI, Tsutomu EZUMI, Masashi HACHIYA
Article type: Article
Session ID: J0202-4-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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I In this research, the deformation characteristic Osteoarthritis of Hip Joint was picked up. Presently, most increase of operation number of cases is anticipated, strong admiration is directed. In this case, it reports on the analysis that uses the principal stress diagram that is the feature of another of the comparison between a groin arthropathy end and a normality state and photoelasticity. The test piece model for the state of mechanics of the transformable Osteoarthritis of Hip Joint and the distribution of bone trabeculae was made. and the state of mechanics and the effect of the operation were examined experimenting dynamically. The experiment analysis was done by chiefly using 3-Dimensional Photoelasticity former stress freezing method for a mechanical approach. As the result, the arrangement of singular point differs in Osteoarthritis of the Hip.
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Takaaki SATO, Hitoshi MIYAKE
Article type: Article
Session ID: J0202-4-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Lots of utilities in the investigation that based on biology and anatomy are exists. A new sensor it mimicked the muscle spindle is developed. If it will be included the muscle-nervous system near it, it behaves more excellent mimetics. So the sensor system needs a suitable control algorithm.
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Michihito AOKI, Mariko HAYATA, Takuji KOIKE, Kyoji HOMMA
Article type: Article
Session ID: J0202-4-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Mussel adhesive protein (MAP) is expected to be used as a new artificial adhesive material for bonding under wet conditions such as surgical incisions. The adhesive strength of MAP, however, has not been accurately measured until now for practical use. The study aims to clarify the time variation of adhesive strength from an engineering perspective. Adhesive strengths have been measured during the range from ready to one month after adhesion setup, using prototype peel test procedure. The results show that the adhesive strength depends on time and repeated seesawing strength with the elapse of days.
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Shinya KOSEKI, Kousuke IGA, Noriaki TABATA, Hiromu HASHIMOTO
Article type: Article
Session ID: J0202-4-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The purpose of this study is to bring out Dragonfly's aerodynamic characteristics. It is very difficult to know aerodynamic characteristics of the Dragonfly using the conventional observation technology when it is flying freely. Therefore we developed the wing motion simulator which have same wing interval as natural Dragonfly's and we visualized the flow around the wing in flapping motion using it. It is clarified how wing interval influences aerodynamic characteristic of Dragonfly.
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Hiroki Ishida, Tomonori Tsukiya, Eisuke Tatsumi, Kenkichi Ohba
Article type: Article
Session ID: J0203-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Flow in a centrifugal pump Ventricular Assist Device (VAD) under the pulsatile flow condition was visualized to investigate the effect of pulsatile on the flow conditions. In this paper, we measured the flow distribution with Laser Doppler Velocimeter (LDV) between the impeller and the pump casing, which is supposed to affect the blood-cell destruction in the device. The VAD rotating speed was 2100rpm and the flow rate through the VAD varied from 0 to 13L/min (mean 5.3L/min). The flow velocity decreased in the high flow rates, and increased in the low flow rates. Under the steady flow of 4L/min, the wall shear stress (WSS) was 10Pa, on the other hand, under the pulsatile flow, the WSS varied in the range of 3-10Pa, and was 7Pa on an average.
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Kaoru MATSUMOTO, Shigeho NODA, Kazuaki FUKASAKU, Ryutaro HIMENO, Makot ...
Article type: Article
Session ID: J0203-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The coil embolization for cerebral aneurysm is one of the effective treatments. However, sometimes blood flow may induce recanalization or growth of the aneurysm. Therefore, the measurements of flow speed with coils in aneurysm are necessary for analyzing the effect of coil on the flow in the aneurysm. However, the method for quantitative measurement using an optical image based velocimetry such as PIV has not been established because coil makes shades in flow field. In this study, we tried to identify the shades by coils and the traces by particles by superimposing consecutive images. Several parts of coils are placed on out of aneurysm cavity and it placement may induce that the speed in inflow zone with coils is larger than that of no coil model. These results will clarify the relationship between coil formation at the neck and the flow in aneurysm.
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Shuichi MOCHIZUKI, Koki TAKIURA
Article type: Article
Session ID: J0203-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The hemolytic characteristics are important in the blood-contacting artificial organs, such as blood pumps, hemodialyzers and oxygenators of heart lung machines. Present methods that evaluate the hemolysis in artificial organs are based on the measurement of the plasma free hemoglobin. The cyanomethemoglobin method is widely used, but potassium cyanide (KCN) is highly toxic and the measurement requires at least several minutes for one blood sample. Therefore, the cyanomethemoglobin method cannot realize the real-time measurement of hemolysis. In this study, chemical luminescence technique using luminol was applied to measure the hemoglobin concentration in the blood sample, and a new method was attempted to detect where hemolysis occurred in real time.
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Futoshi MORI, Hiroshi OHTAKE, Junichiro SANADA, Keiichi KIMURA, Osamu ...
Article type: Article
Session ID: J0203-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The selection of an extremely careful treatment method is requested from the treatment of the aortic aneurysm. In the medical field, the diagnosis by the medical image is used and can easily follow-up. However, there is a limit only by the diagnostic imaging, because the various situations are assumed in aortic aneurysm rupture. We examined about progress, develop and rupture of aneurysm due to aortic dissection using time-series medical images using CFD simulation. As the results, pressures of shape of immediately rupture is higher than former shape and observed the vortex and low wall shear stress in aortic aneurysm. The result showed the factor that effect progress, develop and rupture of aortic aneurysm. Therefore, it is thought that profitable information can be given by combining a clinical diagnosis and this result.
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Hitomi ANZAI, Yuriko TAKESHIMA, Toshio NAKAYAMA, Makoto OHTA
Article type: Article
Session ID: J0203-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The effect of stent on the flow reduction in cerebral aneurysm has been reported in CFD studies showing the stent position or the strut shape may affect the flow reduction. The 3D visualization may help easily to specify the inlet zone from parent artery to aneurysm and to find the relationship between the effective strut position and the flow pattern. Then we simulated adding a strut to a stent model on the inlet zone after specifying the zone using 3D visualization system. After moving the strut and repeating the visualization of results, we found a strut on the zone may reduce the flow into aneurysm effectively. The results may suggest the 3D visualization is useful for the assessment of strut position with effective reduction of flow into aneurysm.
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Taichi TABATA, Masaaki HORIE
Article type: Article
Session ID: J0203-1-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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A heart transplant operation has been proposed as the best cure for serious heart disease. But the Organ Transplant Law in Japan has not approved an organ transplant for pediatric patients. Most pediatric patients have to take an operation for heart transplant in Europe and America. However, many patients die before transplant operation is done, because the pediatric donor is extremely few in all over the world. The aim of the research is to examine the hydraulic properties and the pump efficiency of pediatric pump, which is downsized model based on the magnetically suspended centrifugal blood pump (MSCP), by using numerical analysis. As a result, flow pattern was almost similar to conventional MSCP and pump performance is satisfied for pediatric use. Also, it was found that extending blades length for inside and reducing the number of blades increase the pump efficiency.
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Motoaki FUJI, Haruhisa HURUMOTO, Tsutomu TAJIKAWA, Kenkichi OHBA
Article type: Article
Session ID: J0203-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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It is clarified that when endothelial cell covering over aortic valve is damaged, the aortic valve is hardened, which is known as aortic valve sclerosis. However, it is almost unknown that how and why endothelial cells are damaged. In this study, realistic models of aortic leaflets and aortic root were made, and the shear stress and normal stress acting on the model leaflet was measured by stereo PIV and observation of model leaflet. As a result, it is found that the shear stress and normal stress act along the model leaflet in the vicinity of its root in a diastole, and it was suggested that these stresses caused by blood flow were factors of the endothelial cell damages.
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Ryo TOYAO, Masaaki TAMAGAWA
Article type: Article
Session ID: J0203-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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This paper describes the visualization of thrombus formation process by using the plasma water to develop the CFD based prediction method of thrombus formation. The experimental apparatus has one orifice pipe that is a simplified model of shear flow in the rotary blood pumps and the stent device. In the first step, the flow in the orifice pipe flow is analyzed by CFD and the shear rate distribution is shown in the case of steady and pulsate flow. In the second step, the thrombus formation process is visualized for constructing the prediction model of thrombus formation. The feature of the experiment is to observe the thrombus formation process by image processing and to quantify the index of thrombus by using blood plasma. Comparing the experimental result with CFD-based shear rate distribution, it is found that the early thrombus is generated at the part where the shear rate of the orifices is high, and the formation speed is dependent on the gradient of shear rate.
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Shingo FUJIMORI, Takao INAMURA, Hideki YANAOKA, Minori SHIROTA, Ikuo F ...
Article type: Article
Session ID: J0203-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The liquid flow perfused from a cannula into an aortic arch glass model was visualized by using the PIV method. The transparent glass model of a human aortic arch was fabricated based on the CT image of that of a normal adult man. One of five different cannulae actually used in surgical operation was inserted into the glass model. Glycerol aqueous solution having viscosity of 2.403×10^<-3> Pa s was circulated in the model at the flow rate of 4.0 L/min. A laser sheet was irradiated to the flow field simulating an extracorporeal circulation in aortic arch model to capture velocity vectors. Velocity distributions and streamlines in side and cross sectional planes were obtained based on velocity vectors. Based on the result obtained. the comparison of the flow in each cannula was performed.
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Kenta YUKI, Takao INAMURA, Hideki YANAOKA, Minori SHIROTA, Ikuo FUKUDA ...
Article type: Article
Session ID: J0203-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Blood flow in an aortic arch with aneurysm was simulated numerically by using a commercial CFD solver, STAR-CD. The difference in flow field perfused from two different cannulae, i.e., curved end-hole and dispersion cannulae was analyzed in detail. The numerical models of aortic arch and cannula were independently reconstructed from CT images. The cannula model was then inserted, with appropriate position, depth and angle, into the aortic arch model. It was found that the perfusion velocity from dispersion cannula was smaller than that from the curved end-hole cannula because of greater attenuation in typical filmy jet flow from dispersion cannula. This filmy jet flow decreases maximum wall shear stress on the inner surface of aortic arch by one-fifth compared to the straight jet flow perfused from the end-hole cannula.
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Hiroyuki SHIOTA, Takanori TAKENO, Hiroyuki MIKI, Toshiyuki TAKAGI
Article type: Article
Session ID: J0203-2-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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NiTi shape memory alloys (SMAs) are widely used for medical devises utilizing a shape memory effect. However, release of the Ni ions from SMA into a human body is one of the significant issues to be solved because Ni ions cause the allergenic reaction. Diamond-like carbon (DLC) coating is one of the promising materials that can prevent the release of such ions. To use DLC as coating materials, fatigue strength to endure cyclic bending of the SMA substrate is required. Although conventional DLC coating is very brittle and show weak adhesive strength to metallic substrate, the addition of metal into a DLC matrix has the potential to show good adhesiveness and bending flexibility. In this study, fatigue strength of tungsten-containing DLC coating on a SMA plate was investigated. DLC was deposited on a SMA plate by radio-frequency chemical vapor deposition method and also co-sputtering of a metal target. Fatigue strength of the coatings has been characterized by applying 1% cyclic bending strain. Coated surfaces were observed after bending test using an optical microscope and a scanning electron microscope.
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