We have previously developed hybrid unsteady-flow simulation combining particle tracking velocimetry (PTV) and direct numerical simulation (DNS) and demonstrated its capability at low Reynolds numbers. Applying algorithms of this type, however, becomes more challenging with increasing Reynolds number because the time interval of the PTV frame rate becomes much greater than the required DNS time-step, and the PTV resolution tends to be lower than that necessary for DNS. To extend the applicability to noisy time-resolved PTV data, the proposed algorithm optimizes the data input temporally and spatially by introducing a reduced-order Kalman filter. This study establishes a framework of the Kalman-filtered hybrid simulation and proves the concept based on a planar-jet flow at Re = 2000.

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Except problems of interpretation of the visualized results, most studies about the state of the arts of visualization techniques will focus on the processing of the huge amount of data (for example, tens or hundreds of millions of grid points). On the other hand, it is not easy to visualize a three-dimensional vector field comprehensibly even for one-tenth million grid points. Some intelligible representing methods have been developed. In this paper, we survey the methods and will show some new solutions.

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The Kolmogorov complexity which measures the randomness were introduced. Numerical and graphic data in the mixing layer which was formed downstream of two-dimensional nozzle exit were compressed with the aid of a compression program. Approximated Kolmogorov complexity, AK, and normalized compression distance, NCD, were obtained. First of all, data compression format was tested among six formats. The 7z format was the best format, since the NCD between same data was almost zero. This format was suitable for the symmetrical, non-zero and triangle inequality properties of the maxim of distance. The AK indicated the regularity of the laminar flow and the randomness of the turbulent flow quantitatively. The NCD of the numerical value varied with data length. Between the same data, it approached zero, yet, on the other hand, between different data, it approached unity as the data length increased.

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A randomness factor has been proposed that for the measure of the laminar-turbulent transition process in a mixing layer. This factor had disadvantage that it takes two values in the same flow condition. Therefore, the new measure to show the laminar-turbulent transition properly in proposed in the present investigation. Numerical and graphic data in the mixing layer which was formed downstream of two-dimensional nozzle exit were compressed with the aid of a compression program. Approximated Kolmogorov complexity, AK, and normalized compression distance, NCD were obtained. The AK indicated the regularity of the laminar flow and the randomness of the turbulent flow quantitatively. The NCD of the numerical value in the natural transition process in the mixing layer increased monotonically downstream. Thus the NCD appears to be the measure of the transition process. In the natural transition process in the mixing layer, the AK of the numerical value and the NCD of the graphic data did not change monotonously in the downstream direction. Thus they contain some uncertainty for the measure of the transition process.

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Recently in Japan, the interest in clean energy has been increasing especially after the nuclear accident in Fukushima. There is a wind power as one of the clean energy source. However, the wind power generation is difficult to increase the efficiency. Therefore, there is a wind-lends windmill as efficient it. We study the shape of wind-lends. Wind-lends is able to improve the efficiency of wind power generation. It made a difference in pressure between front and behind the windmill and the wind flow faster. This result depending on the shape of wind-lends. To optimize the shape of it, using Taguchi-method. Taguchi-method shows in the strength of the effect on each parameter of wind-lends. In experiments with Eiffel type wind tunnel, the pitot-tube and manometer are used to measure the velocity of the wind. The experimental results are analyzed using the regression-analysis. We select the optimal value for each parameter from the analysis results and determine the optimal shape. This study shows a trend of good shape of the wind-lends

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Taylor vortex flow appears between two concentric rotating cylinders, for example, fluid bearings of hard disks etc. Cylinder torque applied to the cylinder walls and mean kinetic energy change sharply, and it leads to the deterioration and destruction of the container. The governing parameter of the flow are the aspect ratio and Reynolds number. The aspect ratio of the cylinder height to the gap between the inner and outer cylinders. Reynolds number is defined using the speed of the inner cylinder. In this study, Taylor vortex flow is analyzed by numerical simulation. We investigate the effect of the boundary conditions on the Taylor vortex flow.

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In a study of a flow caused by a rotating disk in a casing, as for many of past studies, most of the form of the rotating disk is not considered. However, it became clear by the study of late years that a radial gap affected the flow between the casing base and rotating disks greatly. In this study, we used 7 different rotating disks and changed the size of the gap in the cylinder casing and tested it about the influence that the radial gap gave to the flow near the fixed disk. As a result, it has been observed that "bead-like-vortex" is generated in one of seven disks. "Bead-like-vortex" is investigated in detail and the result of the experiment is shown in this paper.

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The pattern changes of flows around a rotating disk in a cylindrical casing are investigated by the numerical approach. The disk has a radius smaller than the inner radius of the casing and it also possesses a finite thickness. This geometrical configuration is the model of rotating fluid machinery such as pumps and turbine rotors. In the radial gap between the disk rim and the side wall of the casing, the flows driven by the centrifugal force appear and make disturbances. These disturbances bring various kinds of flow patterns. When the rotating angular velocity of the disk is low, axisymmetric flow emerges and the flow in the radial gap is Taylor-Couette flow. As the angular velocity increases, sickle-like vortices, bead-like vortices, spiral rolls appear. The appearance of these flow patterns depends on the geometrical size of the disk. In this paper, the effect of the disk thickness is investigated and the critical Reynolds numbers for the appearances of flow patterns are determined.

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It is desirable that fuel is continuously supplied to the gasoline tank intake, even when we have got on vehicle with nearly empty fuel. As a means which reduces surface agitation by sloshing, giving baffles to a tank is often considered. In this study, we simulate sloshing phenomena based on the Navier-Stokes equation by using of volume of fluid (VOF) model and non iterative time advancement (NITA) scheme. We examine the accuracy and efficiency of calculation by using of NITA scheme, which varies depending on two kinds of algorithms and under-relaxation factors. In the simulation of flow visualization, the tank with baffles is analyzed first. Then, the baffles are switched from wall boundaries to interior boundaries and the tank without baffles is analyzed under the same conditions as the tank with baffles. Finally, liquid interface and velocity magnitude are indicated by a contour.

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Shaken baby syndrome (SBS) is a type of traumatic brain injury caused by violent shaking of an infant head. It's characterized by some forms of intracranial damages such as subdural hemorrhage, gliding contusion, or diffuse axonal injury. However the mechanism of SBS is not yet clearly understood. In this study, we analyzed intracerebral stress distribution by photoelastic analysis using a two-dimensional sagittal-plane gelatin brain model to elucidate the mechanism underlying intracranial damages in SBS. We modified Holbourn's brain model and added the lateral ventricle. The device consisted of rotational table, green light source, linear polarizer, the gelatin model, and high speed polarized camera. The model oscillated rotationally in the sagittal direction with 60 degrees of central angle and 3Hz of frequency. The peak average values during flexion (negative value) and extension (positive value) of sagittal linear acceleration, angular velocity and angular acceleration were -1.31G, 1.24G, -3.93rad/s, 5.75rad/s, -148.64rad/s^2, 107.06rad/s^2, respectively. In color image for retardation indicating stress generations, stress wave began to appear in the parietal region near the brain surface and the deep region of the brain, after that before full flexion of the model, stress concentration could be observed in the parietal region near the brain surface, midbrain and the corpus callosum. These results suggest the mechanism of occurrence of subdural hemorrhage, brain damage such as gliding contusion or diffuse axonal injury in SBS.

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Mechanism of an infantile subdual hematoma has been controversial. It is not known whether the injury occurs in physical abuse or accident, or both. This is because it cannot observe the relative motion between skull and brain in the infant dummy with conventional rigid head though it is thought briding vein stretch by the relative motion between skull and brain is most likely to poroduce acute subdual hematomas.To identify the influence of height and first imact body region on intracranial brain motion, we developed a dummy which visualizes the relative motion between skull and brain, and conducted experiments dropping the dummy onto wooden surface. As the results, HIC significantly increased (P<0.001) with increase of fall height, but peak briding vein steretch ratio was not depenent on fall height (P=0.76). HIC (P<0.05) and peak briding vein steretch ratio (P<0.001) were significantly affected by first impact body region.

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This paper describes studies to understand the fundamental mechanism of the collision and fall induced human injury by using dummy in the experiment. In our dummy experiments, the dummy on the cart is collided by the other dummy and fallen on the floor. It is concluded that the injure criteria was effected by the initial position and pose of dummy, HIC (Head Injury Criteria) decrease under the safety area with helmet in all cases of these dummy experiments.

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In 2012, Judo was compulsory course at junior high schools. The number of dead or injured in judo is more numerous than that of other sports and the most of them are beginners. Therefore, the number of dead or injured would extremely increase when judo is the compulsory course. The most serious head injury is acute subdural hematoma (ASDH). The purpose of this study is to compare the evaluation index for ASDH occurrence and evaluate head protector's effect. We measured the head acceleration during the falling and calculated HIC, maximum angular acceleration and variation width of angular velocity. The results show that the variation width of angular velocity has the highest relative coefficient with the relative displacement between brain and skull and, thus, it is the candidate as the evaluation index of ASDH occurrence. In order to prevent ASDH occurrence, it is suggested that a head protector should be made of shock absorbing materials with a small coefficient of restitution to reduce the rebound velocity of the skull after collision.

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Diffuse axonal injury (DAI), a major component of traumatic brain injury, is associated with rapid deformation of brain tissue resulting in the stretching of neural axons. Focal axonal swelling, which is the morphological hallmarks of DAI pathology, leads to the disconnection of neurons from tissues, resulting in cell death. In present study, PC 12 cells, which extend structurally axon-like cylindrical protrusions in culture, were stretched to a strain magnitude of 15-100% at strain rates of 30-80 s^<-1>, or left as static culture using an in vitro stretch injury device that subjected cultured cells to a wide range of mechanical stretch that are experienced during in vivo head injury. Following mechanical loading, we assessed neurite swelling and neuronal viability. As a result, the increase in early neurite swelling was dependent on the severity of the stretch, and neuronal viability at 24 h post-injury decrease in a stretch-dependent manner. These results suggest that the formation of neurite swellings correlates with the mechanical exposure.

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Skin laceration often occurs in daily life due to contact with curvatured edge of manufactured product in an accident. In this study, mechanical conditions for skin laceration to occur due to contact with curvatured edge were experimentally investigated by pressing several curvatured blades into a skin substitution material using a universal testing machine. The skin substitution material was made from silicon rubber, and has good agreement with published human skin characteristic data in terms of mechanical properties. During the penetration tests, reaction force and penetration level as well as deformation behavior of the skin substitution material were obtained and then analyzed to determine the mechanical conditions for rupture to occur. It was found that blade with small radius of curvature causes rupture more easily than blade with larger radius of curvature. Furthermore, radius of curvature of the blade also shows a strong linear relationship with reaction force and penetration level at the time when the rupture occurs.

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The Flexible Pedestrian Legform Impactor (Flex-PLI), is developed by Japan Automobile Manufacturers Association (JAMA) and Japan Automobile Research Institute (JARI) to improve bio-fidelity of the ongoing legform impactor developed by TRL (Transport Research Laboratory). This paper presents simulation results of Flex-PLI shots to SUV (Sport-Utility Vehicle) and examines its kinematics. The results are compared with those of Human FE (Finite Element) model.

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Traumatic Brain Injury is the most dangerous trauma for occupant death in car accident. Traditionally, occupant protection research for automotive safety has been used human head dummy. This dummy can assess traumatic brain injury by translatory and rotational acceleration. According to basic research for brain trauma in micro level injury, brain deformation brings on nerve injury. In traumatic brain injury derived from rotational acceleration, brain deformation and nerve injury is important factor for serve brain injury. However, HIC can't assess these factors. Therefore, we developed human head dummy for assessment of nerve injury. This dummy has alternate brain interiorly. Alternate brain is made by gelatin and contains the microcapsules. According to basic research for nerve injury in traumatic brain injury, mechanical strain to brain neuron produces intracellular Ca^<2+> increase in 30% brain strain. The purpose of this investigation is to reconstruct this brain mechanism by alternate brain.

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Nihon University and Nippon Medical School research the traffic accident. This study analyzed anatomical damage and the vehicle damage of the findings from medical and engineering. Abdominal injury is the largest in seatbelt user's death and serious injury rate. Generating mechanism should be solved fast. The research example which abdominal injury occurred had the feature which the sheet bearing has damaged. It case had been suffered abdominal injury seatbelt is removed from the pelvic region. Abdominal injury, it is necessary for the anatomical evaluation of AIS of bleeding increases with time, even minor injuries. To simulate the behavior obtained from the survey crew, we want to clarify the generation mechanism of abdominal injury.

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The main role of cardiopulmonary bypass system is to send the oxygenated blood to the patient. Oxygenator which is a component part of cardiopulmonary bypass system adds O_2 to blood and removes CO_2. The type of oxygenator which is used most often today is hollow fiber membrane oxygenator which transfers O_2 and CO_2 through micro porous membrane. The design concepts of oxygenator are a low priming volume and a low foreign substance contact surface. The design of oxygenator is carried out by selecting a gas exchange membrane and structure, determining the specification which depends on the size of the patient, etc. JMS original design which has circular pathway was developed based on the concept of "simplification of the blood pathway". This oxygenator has the pathway in whichblood flows uniformly and has high gas exchange efficiency.

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Phacoemulsification is most popular surgical method of cataract surgery. During operation, crystalline lens is fragmented and aspirated before insertion of the artificial lens being into intraocular. Here the fragments of crystalline lens are scattered in the posterior chamber and might impinge onto the endothelial surface of the cornea. This is a possible cause of the loss of the endothelial cell during the cataract surgery, although it was not clarified in detail so far. In order to clarity the influence of impingement of the fragments on the cells of corneal endothelium, corneal endothelium exposed to jet of physiological saline which contains the fragment and calculated damage rates of the cells. Damage rate tended to become higher so that velocity of jet becomes fast. And also when the one that included the fragments did not include the fragments, damage rate was higher.

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Cochlear implant is a device that provides electrical stimulation directly to the cochlea. Stimulation pulses emitted from the inserted electrode is transmitted to the brain through the auditory nerves in the cochlea. Some patients with significant hearin g loss still have residual hearing for low frequencies. An attempt has been made to amplify acoustic sound at low frequencies with a conventional hearing aid and to apply electrical stimulation for the middle and high frequencies with the cochlear implant. This device is called the electric-acoustic stimulation (EAS). In this study, the electrode for the electric-acoustic stimulation was optimized by using a three dimensional finite-element model of the human cochlea. Dynamic behavior of the basilar membrane (BM) and the cochlear fluid caused by the vibration of the stapes footplate were analyzed. The effect of the Young's modulus of the electrode on the vibration of the BM was examined by modeling the electrode in the cochlea model. The results suggest that BM has large amplitude at low frequencies and the residual hearing is preserved by reducing the stiffness of the base of the electrode.

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Focal cooling for termination of epileptic discharges has recently become a focus of research. The authors reported on a newly devised cooling system that uses a Peltier chip and a heat sink. A Peltier chip changes dynamic characteristics under the condition of use, so be known that temperature control is difficult. With the goal of construct the temperature control method of the devise, discussed the mathematical model, unknown parameters of the model and a nonlinear control method. First, the authors developed the mathematical model basis on the equation about Peltier chip-heat sink energy balance. Second, the authors experimented to know basic performance of the devise. Third, the authors identified unknown parameters based on an optimal method using experimental results. Forth, the authors discussed control method about both the PID control and the sliding mode control. As a result, the mathematical model can fully simulate temperature variation of the device as long as consider of parameter variation. Finally, the sliding mode control method was shown to be of benefit in temperature control using a Peltier chip

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The purpose of this research is to demonstrate a methodology manufacturing a desired depth on silicon which can be used for a mold of transferring to polymer. A gray-scale photolithography technique was demonstrated using deep reactive ion etching (DRIE). The whole photo-lithography process is carried out in two steps: (i) photoresist structure transferred into the silicon using a layout mask, (ii) a silicon mold is formed using gradation exposure through the use of gradation mask and DRIE. The selectivity was 8.1 and the maximum depth reached 30μm.

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Osteoarthritis (OA) is the most common degenerative joint disease in the field of orthopaedics. In advanced stages of OA, the patients suffer from severe pain, functional limitations in the affected joints, and restriction of mobility. For detecting early OA and the prevention of progression in OA by novel therapeutic strategies, they are important to understand the functional properties of synovial joint and to establish the precise measurement technique. Pendulum friction test is one of the mechanical evaluations for lubrication properties of joints. The advantages of this method are the natural motion without the constraints of joint and also preservation of the joint capsule, the synovial fluid in it and the tendons and ligaments around the knee. In this study, in addition to the friction properties, the viscous and elastic effects were evaluated. The equation of motion of joint cartilage were proposed including the friction, viscous and elastic effect. The each mechanical parameters were identified by fitting the damping oscillation curve measured by pendulum terster with two laser displacement sensors and an accelerometer.

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Human knee joints can support high levels of mechanical load for decades. The mechanical factor plays an important role in the development of osteoarthritis of the knee that interferes to daily life. It is recognized that the morphological change due to the injury or thinning of meniscus may influence the mechanical environment of the knee cartilage and meniscus. To investigate the effects of the thinning of meniscus in activities of daily living, three dimensional finite element models of two knee joints, the normal one and the one with thinning of the meniscus, were constructed from the medical images, and the finite element contact analysis of the knee joint was carried out in the present study. The load condition during activities of daily living(level walking, ascending/descending stairs) was introduced in the analysis. The results show that the stress magnitude and the location with the highest contact stress in the tibial cartilage are different in each activities. The higher stress and larger deformation were observed in the knee joint during ascending/descending stairs compared with level walking, The larger strain was observed in the surface of tibia in the knee joint with thinning of meniscus.

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In performing the flexor tendon repair, peripheral suture is essential to improve the sufficient strength and to accomplish the early active mobilization of repaired flexor tendons. It has been reported the interlocking cross-stitch peripheral suture is increased the strength. The purpose of this study was to evaluate about various interlocking cross-stitch peripheral suture under cyclic loading conditions. Artificial rolls, Parotisrolls^<TM> were used as the experimental model in this study. We sutured the end of the two artificial rolls using a combination of peripheral sutures. All pairs of the artificial roll tendon model were sutured using only peripheral sutures with 6-0 Polypropylene. The suture bites were placed 2mm, 3mm, 4mm, 5mm, 6mm, 8mm and 12mm away from the end of the roll. Each bite was approximately 1mm in depth and the size of transverse segments of each cross-stitch suture was 4mm. An initial cyclic load of 10 N for 500 cycles was applied and increased by 5 N for an additional 500 cycles at each new load until rupture. In result, the interlocking cross-stitch peripheral suture that the suture bite distance is long, improved the strength of the specimen. However, in the face of realization of smooth motion after flexor tendon repair, suture bite of 8mm or more is unrealistic. Therefore, it was considered to be valid suture bite of 8mm from 5mm.

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AE monitoring of damage process of rabbit patellar tendon under static tensile load was carried out. Considering strong viscoelasticity of tendon, load was applied at various loading rate (10, 1, 0.1 mm/min) until the complete rupture in physiological saline at 37℃. The displacement of the specimen was monitored by a digital video camera, and acquired images were used for determining the displacement distribution in tendon by the digital image correlation (DIC) technique. It was found that AE signals were detected before the maximum load and AE source locations corresponded to the locally elongated area, which indicates that fascicle failure takes place before the maximum load. The average failure stress increased as loading rate increased, and the differences in average failure stress were considered to be statistically significant. Consequently, the fundamental insights for the damage monitoring technique which are indispensable for the optimization of programs of sports training or rehabilitation are obtained.

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The mechanical characteristics of the patellar tendon are primarily derived from cadaver studies, which may not necessarily be applicable to the human patellar tendon, in vivo; however, recent developments in high-resolution magnetic resonance imaging (MRI) techniques have opened up new perspectives for structural characteristics of the tendon and ligament by non-invasive methods. The purpose of this study is to use MRI to quantity the elongation and the strain of the human patellar tendon in vivo during full extension to 60° of knee flexion. The apparent elongation in the lateral-central (lc) portion of the patellar tendon was slightly less than in the central (c) and medial-central (mc) portions with knee flexion. The apparent mean-central strains (mnc = (c + mc + lc) / 3) of the patellar tendons, which corresponded to strains in the central one-third portions of patellar tendons, were (average and standard deviation) 0.091 ± 0.034 and 0.135 ± 0.007 at 30° and 60° of the knee flexion, respectively.

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This study demonstrates the deformation of the surface area of human skin around knee joint during knee flexion. Ten young-male subjects (age: 21.4±0.69) with intact knee were included in this study. The subjects stood barefoot in uplight stance and did knee flexion exercises (20, 40, 60, 80 degrees). The surface area of skin, knee joint, hip joint and ankle joint angle were respectively measured during the experiment using 3-dimensional motion capture systems. The results showed that 1) the skin at the medial side from top of the patella and the back of the knee from lateral side were respectively expanded and contracted during knee flexion, 2) in the calf and thigh areas, the deformation of skin were changed from contracting to expanding with the increase of knee flexion angle.

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Hematopoietic stem cells in the blood vessels differentiate into osteoclasts on the bone tissue. We hypothesized that the differentiation from hematopoietic stem cells to osteoclasts is affected by the substrate elastic modulus. The purpose of this study is demonstration of this hypothesis by evaluating the effect of the substrate elastic modulus on the differentiation from hematopoietic stem cells to osteoclasts. Hematopoietic stem cells were cultured and differentiated on substrates with different elastic modulus using M-CSF and RANKL. We prepared collagen gel substrates with different elastic modulus by changing cross-linking agent concentration and collagen concentration. The differentiation from hematopoietic stem cells to osteoclasts was checked by using observation of cellular morphology and TRAP staining. As a result, number of osteoclasts differentiated from hematopoietic stem cells on the hard substrate was more than 10 times of that on the soft substrate. This suggests that mechanosensing of substrate elastic modulus is one of the keys of the differentiation from hematopoietic stem cells to osteoclasts.

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In this study, in order to measure the softness of cultured tissue, ball indentation tests were performed. As first step, the principle of ball indentation test was applied to the thin silicone rubber sheet (t=0.1mm), which achieved results confirm the validation of the measurement result. Next step, Young's modulus of monolayer cultured nerve cell (PCI2) was measured, and the validation of the measured results was confirmed by comparing with previous studies. The Young's modulus of the cell body is 36.5kPa, and distal, middle and proximal of neuritis are 50.2kPa, 21.8kPa and 51.5kPa, respectively. In addition, Young's modulus of three-dimensional gel-culture system consisting of primary human gingival fibroblasts (GF) and gingival epithelial (GE) cells in collagen gels were measured. The Young's modulus of whole gel and gingival epithelial cells are 3.46kPa and 81.9kPa, respectively. The results were shown the possibility of measuring the Young's modulus of each layer of cultured tissue in the case of laminate structure.

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Degradation of extra-cellular matrices is an integral pathophysiological part in periodontitis. Previously, we have isolated "aggressive fibroblasts" derived from severe periodontitis regions from human patients and established an in vitro periodontitis model using a three dimensional (3D) culture system. We have been screened candidate drugs for periodontitis by evaluating inhibition of collagen degradation employing this model. Although several drugs effectively inhibited collagen gel degradation, some of them have resulted fragile collagen gel. Therefore, we tried to evaluate collagen gel "softness" using ball indentation tests together with residual amount of collagen. Evaluation of candidate drugs by the Young's modulus of in vitro periodontitis model was useful, and one of the drugs (herbal medicines) successfully improved "softness" of the gel. These results suggested that the measurement of the Young's modulus of in vitro periodontitis model may be a useful tool for screening of candidate drugs for periodontitis.

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Magnetic resonance elastography (MRE) is a newly developed imaging technique that makes full use of the magnetic resonance imaging (MRI) visualization to measure the stiffness of tissue in the body organs using mechanical excitation. In this study, an excitation device for MRE by micro-MRI (0.3T) was constructed from a high power vibration generator and a bar type vibration transmitter made from GFRP. The stiffness was expressed by storage shear modulus G' and loss shear modulus G" of the modified stokes model for a viscoelastic medium. Using a micro-MRI system, the optimal excitation condition of frequency and amplitude of wave was examined using some gel specimens. Viscoelastic modulus distribution of two layered agarose gel specimens were measured in the excitation condition of amplitude (0.5, 1.0, and 1.5 mm) and frequency (62.5, 125, and 250 Hz). The distribution of G' was influenced by both the frequency and amplitude of excitation. The two layered specimen combined with two different concentration gel samples shows the same tendency of G' in the same concentration layer approaching similar values under the higher excitation amplitude and frequency conditions as the uniform agarose gel specimen. Clear differences of the wave propagation patterns were observed in the MR image and the difference of G' between each phase area could be measured quantitatively in this MRE system.

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When bringing regenerated cartilage into practical use, due to its piece to piece property difference, non-invasive assessment methods should be developed. We intended to achieve non-invasive assessment of cartilage by applying terahertz technology. The purpose of this research is to clarify the relation between cartilage characteristics and terahertz spectra.In this paper, we clarified the relation between the amount of free/bond water in cartilage, which is one of the factors that decides the characteristic of cartilage, and absorbance of the terahertz wave by measuring natural bovine cartilage, natural bovine cartilage treated with enzyme and gel components of cartilage which are gelatin gel and chondroitin sulfate gel.

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We developed a Multipoint Laser Doppler Velocimeter (MLDV) system for the simultaneous measurement of data in transparent fluid. The MLDV was constructed in order to apply linear measurement techniques to a series of single points. We developed of MLDV using a linear optical plastic fiber array and were able to improve the measurement of opaque fluids, such as blood. This fiber array has 40 optical fibers with a total width of 5.0 mm; each optical fiber has a core diameter of 100 μm. Some performances have greatly improved compared with a conventional laser Doppler blood flowmeter. The present system can measure absolute velocity and, based on this, can display the tomograph of blood vessels courses. The spatial resolutions of each of x-y axes and z axis in this system are 100 and 500 μm. The MLDV is able to acquire the high-resolution in vivo three dimensional mapping of blood flow with the velocity, particularly in the smaller arterioles and venules, by using a scanning method. The MLDV was developed primarily for using in the diagnosis of cancer. We attempted to perform blood flow velocity imaging of a malignant melanoma which transplanted in mouse ear.

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When constructing the one-dimensional systemic artery tree, the Windkessel model based on parameters describing the total resistance and compliance is generally applied as outflow boundary conditions. However, the Windkessel model does not include wave propagation effects, and moreover, it is not obvious how the parameters should be estimated. Hence, the main purpose of this study is to develop an outflow boundary condition based on the underlying physiology of the arterioles, enabling the prediction of blood flow and pressure in the systemic arteries including the arterioles. The obtained numerical results show the followings. Firstly, we verified that applying the structured tree model as an outflow boundary condition can reproduce the essential characteristics of the arterial pulse better than applying the Windkessel model. Secondly, by analyzing the pulse wave velocity in aorta, we found a correlation between pulse wave velocity and the degree of arteriosclerosis which correspond to the clinical observation.

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A new method to specify accurate boundary conditions (BCs) on inlet or outlet boundaries in vascular CFD analysis is proposed. The proposed method corrects the flow velocities measured by 3D cine PC-MR (4D-Flow) velocimetry based on the error characteristics of 4D-Flow and the law of large numbers. Experiments with a rotative phantom are carried out to evaluate the error characteristics of 4D-Flow. The accuracy of a few BCs given by the proposed method is experimentally validated with a straight and curved pipe phantom.

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Human arterial model was proposed by Avolio in 1980. Medium-sized artery and aorta of the body are discretized into 128 segments in the model, and the Young's modulus and dimension of each segment are described. Terminal condition of the aorta is also given as the impedance based on the peripheral resistance. In 2004, John assumed terminal condition to be not only resistance but both resistance and capacitance at the end of this model. In his model, the reflection ratio is defined to be a real number even though there is time delay of pulse wave transmitted into arteriole. In this study, the reflection ratio is defined to be a complex number in our model, and the transfer function of John model and our model are compared. The results suggest that the reflection ratio of the terminal condition should be expressed as complex number and our model is better than John's one.

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Tissue engineering is an alternative approach for the preparation of small-diameter (4-6 mm) vascular grafts due to the potential to control thrombosis, anastomotic cellular hyperplasia and matrix production. Then, in order to make three-dimensional structure, many researches using scaffold have been done. However, scaffold has some problems to make prominent Tissue engineered blood vessels (TEBVs). For example, they are degradation characteristic and mechanical properties, disturbance of interaction between cells. Therefore, we constructed novel Scaffold-free model of TEBVs which does not use scaffold, and we produced TEBVs by using this Scaffold-free model. Moreover, we promoted differentiation of stem cells by cultivating with mechanical stimulus, and we evaluated this result. Also, we evaluated cell differentiation when this model is cultured by not pulsatile flow only radial stress.

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Influence of vascular shape extraction method and Non-Newtonian hemodynamic behavior on WSS distribution estimation on cerebral aneurysm in MR based CFD is evaluated. Firstly, shapes of straight pipe are extracted from Contrast-Enhanced MRA (CE-MRA) image, Phase-Contrast MRA (PC-MRA) image and time avaraged PC-MRA image. With each extracted shape, WSS distribution is calculated using CFD. The WSS ditribution calculated with the shape extracted from CE-MRA image shows the good accuracy with the theoretical distribution, while the result with the shape extracted from PC-MRA images shows unsatisfactory accuracy. Secondly, the WSS distributions computed by CFD considering blood as between Newtonian fluid and Non-Newtonian fluid are compared. The Power Law model and Carreau model are employd as Non-Newtonian model. Because the results obtained with Newtonian model, Power Law model, and Carreau model were almost same, it is concluded that Newtonian model is valid enough to model the blood for evaluating WSS distribution.

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Vascular disease topped the cause of death in Japan in recent years.Atherosclerosis is a typical vascular disease. The blood vessel mechanics is still many questions and evaluate the mechanical characteristics of arteries has become very difficult. One of the causes is mentioned that coupled with the blood vessels and blood flow is complex. In this study, an experiment device was developed that simulate the human circulatory system to evaluate the effect deformation of blood vessels gives flow in the arteries. To compare the experimental results of each of the rigid tube and the elastic tube obtained in this experiment device. The flow of pulsate was evaluated if when there is deformation and when there is no deformation. The length of the tub was focused will give effect to the flow in particular. Changes due to length were evaluated such as pressure drop. When sending the fluid to the tube to deform, it is shown that estimated for the required pressure.

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Stent conformability, the flexibility of a stent in its expanded state to naturally conform to the vessel wall, is one of remaining issues of percutaneous coronary intervention (PCI) with DES, because any quantitative evaluation method for the conformability has not been established although the stent conformability affects clinical outcomes after PCI with DES. Recently, however, an attempt to perform a quantitative evaluation of the conformability by finite element analysis (FEA) has been started. We reviewed a research paper reporting that considerable differences were observed between the stent designs and stent-induced vessel wall stress analyzed by FEA and discussed the relationship between stent designs and its conformability. In order to design a stent having an excellent conformability in the future, we discussed factors of stent design; number of rings per stent-length, number of the links per ring, shape of link connecting rings and number of crests between links. Viewed in this light, a stent having more rings per stent-length, less links per ring, shaped links and more crests between links can be considered factors for better stent conformability. Based on the assumption, we verified the stent conformability of Kaname CoCr Coronary Stent System, the latest coronary stent in Terumo Corporation.

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We have been developing peripheral stent system which is intended to treat stenosed peripheral arteries. Generally, peripheral stent itself is made from a Ni-Ti alloy due to the characteristics of superelasticity and shape memory property. Recently some problems have become obvious . One of the problem is a stent fracture which is caused by metal fatigue. Various characteristics, such as bending, torsion, axial durability and radial force are required to overcome the stent fracture problem. On the other hand, it is difficult to keep all characteristics in a good balance because of the number of the design factors for the peripheral stent. We have adopted a finite element analysis to shorten the time for design optimization. Concequently we could cut down the design time and achieve several promising stent designs.We have also adopted the same method to develop a novel stent delivery system. We found that finite element analysis was the useful tool for developing stent system.

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The purpose of the research is to build is to build a system, which enables to quantitatively evaluate the feature quantity , which inspecting engineer observed, in the smear image. This paper examined the technique of classifying normal leukocytes, and an abnormal cell (ATL cell) of (adult T-cell leukemia) in peripheral blood , using the form feature quantity and color feature quantity of a granule and nucleus .As a classification method, we employ SVM with the feature quantity of a color and morphology quantity. As a result, the normal leukocyte was able to be classified according to the reliability of ninety-five percentage. On the other hand, the classification between ATL and normal cells was not completed only color feature quantity (B<_>MAX) and form feature quantity (the number of area, the degree of circular, and outlines)

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Human aortas get stiffer with aging. This phenomenon has been observed for the whole vascular wall. The physiological intimal thickening is also observed as a response of aging. This may suggest that the stiffening occurs mainly in the luminal side rather than the outer side of the wall. We obtained human ascending aortas from autopsy and carried out uniaxial stretching test for the three kinds of strip-like specimens, i.e., the whole wall without the adventitia, the region of media on the adventitial side (am), and the region of intima and media on the intimal side (i&im). We measured the thickness of the two regions obtained by peeling the whole wall and estimated the stress-strain relationships. Comparisons of the predicted stress-strain curve for the region i&im and the experimental one for the region am show that the region i&im is likely to be stiffer than the region am for the elderly people.

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Developing technique of indentation is presented on the deformation characteristics of human arterial vessels in this paper. For the simulation and the evaluation of conditions in human body, an artificial circulatory circuit is developed to evaluate some assumption on the representations. Then spherical indentation test is performed on the evaluation ofthe Young's modulus of the silicone tubes which are used as virtual artery in the circuit. By using these evaluations conditions, the validity of the assumption is discussed by using the fundamentals of cylindrical thick shell theory. Especially, the validation of derived deformation characteristics is evaluated in the discussion of this paper.

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An aneurysm is blood disease that is caused by blowing up the artery wall. There is high probability of death if it is ruptured. Bypass surgery may be used when it is difficult to treat aneurysms by conventional treatment, for example when the aneurysm is located near branch arteries that should keep the blood flow. There is not so much investigation about the bypass surgery from the point of the flow characteristics. Therefore, the purpose of this study is to investigate the flow-field within the aneurysm by visualization experiments and numerical analyses. As result of experiments it was observed that the flow rate through the branch was increased by using the bypass model. On the other hand, similar flow pattern was obtained from numerical analysis that was performed by two-dimensional incompressible Navier-Stokes simulation.

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Infant's fall accidents are occurring frequently. For comprehensive quantitative estimation of injury risks, it is important to divide the injured time into evasive action, protective reaction, and passive deformation. However, the protective reaction of kinematic and kinetic properties has not been clear. Therefore, in order to solve the mechanism of protective reaction, we construct a biomechanical analysis method of protective reaction. First, we obtained the joint angle data of the actual falling behavior of infants, and investigated the time of protective reaction with the cluster analysis. In kinematic analysis, we investigated the feature of falling motion using principal component analysis. As a result, the shoulder and knee extension movement was represented in second principal component. In kinetic analysis, we identified the joint torque with the fall simulation to reproduce the behavior of protective reaction. As a result, the protective reaction consisted of extension or flexion of limbs and restraint of the body trunk.

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The objective of this study is to verify the osteogenic effect of electrically-induced muscle contraction by analyzing the strain values and distribution in the femoral neck region using the finite element method (FEM). Based on micro CT images and anatomical information, we built a FE model of rat femur and set the boundary conditions with external loads by the rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis, and constrained points by the lateral collateral ligament, medial collateral ligament, anterior cruciate ligament, and posterior cruciate ligament. As a result, the maximum compression strain of 173x10^<-6> has been shown in the femoral neck. The value seems not to be large enough to effectively promote bone formation, suggesting necessary modifications of stimulation regimen for successful implementation.

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We developed the knee supporter that is thin and light weight to prevent the elderly people becoming bedridden due to the falling accident. So we designed the structure of the shock absorber that involved to the knee supporter from the crash analysis. We confirmed designed the new structure of shock absorber 's energy-absorption for each unit weight amount was 9.2 times higher than the old structure of shock absorber.Then, the designed new shock absorber was actually molded and, the molded new shock absorber and the old shock absorber were examined in the falling weight test. As the result, the energy-absorption for each unit volume performance of the new shock-absorber was higher than the old shock absorber.

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