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Takayuki YAMAGATA, Toshiyuki HAYASE
Article type: Article
Session ID: 1109
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Detailed information of the velocity and pressure field of the blood flow is essential to establish an advanced diagnosis and treatment of serious circulatory diseases. Commonly used medical measurement equipments does not provide complete information of blood flow in real-time. In this report, we develop a new blood flow measurement system applying Ultrasonic- Measurement-Integrated (UMI) simulation, that integrates ultrasonography and numerical simulation. The system consists of ultrasonic diagnostic imaging equipment, a graphics workstation, and a calculation server. Computer programs for measurement data acquisition, flow simulation, and visualization are synchronized using socket communication scheme. By considering blood flow velocity measured, the system adjusted the phase of a flow rate waveform automatically to match the cycle of pulsation in real diagnostic images.
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Noritaka YAMAMOTO, Takeshi HIROHATA, Tatsuya MATSUOKA, Daiki DEGUCHI
Article type: Article
Session ID: 1125
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Cylindrical and dumbbell-shaped specimens were made from the diaphyese of rat femurs. These specimens were partially demineralized by immersion in a 0.5M EDTA solution. For the specimens, compressive and tensile tests were performed. With the decrease in the calcium content, the compressive strength decreased and the compressive strain at failure increased. The tensile strength decreased in the same manner as the compressive strength. On the other hand, the tensile strain at failure did not change with the decrease to about 50% in the calcium content.
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Jun-ichi SHIBANO, Michiaki KOBAYASHI, Jun-ichi WADA, Yousuke SHIBATA, ...
Article type: Article
Session ID: 1126
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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This study presents a measurement method of detailed distribution of mechanical properties of bone tissue using a scanning acoustic microscope (SAM). In this method, ultrasound reflection intensities in micro area of the bone tissue are calibrated with luminance values of pixels in a C-mode image of it measured by SAM. Minute distribution of density and elastic modulus could be analyzed by combining the XZ-mode which is used to measure the surface wave velosity. Mechanical properties of femur bones of elderly human and young beagle dog were evaluated by this method. It was found that the elastic modulus in the endosteum side of femur bone of young canine was lower than that in the periosteum side of it. Meanwhile, in the femur bone of elderly human, the elastic modulus in both sides were approximately equal.
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Keisuke MOGI, Shuichi WAKAYAMA
Article type: Article
Session ID: 1127
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Ultrasound propagation behavior of cortical and cancellous bone from bovine femur was investigated. Cortical bone specimens for ultrasonic test was cut to 5mm^3 under flowing water, and longitudinal wave velocity was measured by reflection method using the probe with various frequency (0.5MHz, 1MHz, 2MHz, 5MHz). It was recognized that the cortical bone structure had orthotropic and viscoelastic properties. For cancellous bone, attenuation of ultrasonic wave was significant due to the porous structure. Then reflection method using the probe of 1MHz was employed for ultrasound propagation measurement of cancellous bone. Calculated wavelength ranged from 2.5 and 3mm, which was enough larger than the length of individual trabecular. It is considered that wave propagated in bulk mode for cancellous bone. In addition, compression test and four-point bending test was carried out.
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Takayuki IWATA, Hidetomo KOGURE, Makoto SAKAMOTO, Toshiaki HARA
Article type: Article
Session ID: 1128
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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The purpose of this study is to evaluate the applicability of a dynamic nanoindentation tests to study the viscoelastic features of bone. Twenty-four specimens were obtained from four bovine femoral diaphyses. Dynamic nanoindentation testing is used to determine the mechanical and dynamic viscoelastic properties of cortical bone specimens from the longitudinal direction. The mechanical properties including elastic modulus, hardness, viscoelasticity, storage and loss modulus at the microstructural revels (osteonal bone, interstitial lamellae and plexiform bone) are determined to derive the relationship between viscoelastic behavior and collagen contents.
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Fumikazu KOUDA, Makoto SAKAMOTO, Koichi KOBAYASHI, Jun SAKAI, Hidemi I ...
Article type: Article
Session ID: 1129
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Mechanical understanding of dentin properties of is important for development of new dental materials, and is prerequisite to reveal the function and mechanisms of human hard tissues. In this study, nanoindentation test with specimens from permanent incisor teeth were used to evaluate the gradients in the overall mechanical properties, including nano-hardness and elastic modulus of a human dentin. It is shown from the results that decreasing gradient mechanical properties seems to be existed from crown to root of apex in incisor dentin. The elastic modulus and nano-hardness profiles were characterized by remarkable S-shaped curve for root dentin.
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Youhei HASHIMO, Souichi SAEKI, Takashi SAITO, Takahumi HIRO, Masunori ...
Article type: Article
Session ID: 1130
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Most myocardial infarctions and other acute coronary syndromes are caused by rupture of unstable plaques in the coronary arteries. The intravascular ultrasonic (IVUS) has been generally used for discovery of unstable plaques. Since the spatial resolution of IVUS is about 100 micro m, an unstable plaque can not be determined. Recently, Optical Coherence Tomography (OCT) has been developed as a method of obtaining cross-sectional images of microstructural biological tissue with high resolution, i.e. 1〜10 micro m. Even though using OCT, it is difficult to estimate biomechanical characteristics to diagnose an unstable plaque, because OCT images have just speckle patterns of scattering light from tissue. In this study, presented is Optical Coherence Elastography (OCE) modified by OCT, which can diagnose tissue elasticity distribution. This is based on the recursive cross-correlation method, resulting in deformation vector distribution with high resolution, In addition, the local vector interpolation by least square method is introduced to remove erroneous vectors and smooth vector distribution. This was experimentally applied to compressed isotropic samples. Consequently, uniform strain distribution was obtained to comparison with the conventional cross-correlation method, thus the proposed method was validated.
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Maki OKAMOTO, Nobuo SAKAI, Yoshinori SAWAE, Teruo MURAKAMI
Article type: Article
Session ID: 1131
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Response of chondrocyte to the mechanical stimuli, and the corresponding formation of cytoskeleton are likely to play great roles. Therefore it is important to clarify the architecture and distribution of them. We observed chondrocytes and the cytoskeleton of the porcine articular cartilage surface, in situ, using confocal fluorescence microscopy. In some cases, chondrocytes or cytoskeletons were double stained with integrin (α2) known as extracellular matrix. Additionally, the acquired 2D images were restructed to the 3D. At the surface, chondrocytes are distributed like clusters of several cells, and the contours were not smooth. In the chondrocytes, actin microfilaments spread from the nucleus to the membrane, and the density were especially high at the membrane. Intermediate filaments were thinner, and distributed completely to the cytoplasm. Integrins (α2) are chiefly distributed along the membrane and actin microfilaments.
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Kazunari HAMADA, Tatsuya KIKUCHI, Yuji Tanabe, Makoto SAKAMOTO, Koichi ...
Article type: Article
Session ID: 1132
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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In previous studies, we showed that it was able to determine mechanical properties of cartilages by measuring NIR absorbance after indentation test. In this study, calibration curves for gelatins and human articular cartilages were obtained to estimate their water content quantitatively. NIR absorbance and water content in gelatin and human articular cartilages were measured, and their relations were discussed. Gelatin showed NIR absorbance was proportion to water content. Linear relations between water content per thickness and thickness and NIR absorbance and between thickness and NIR absorbance were found in human articular cartilage. These results enabled us to estimate water content in both gelatin and cartilage by the NIR absorbance. The discrepancy between measured and estimated water content in cartilage was 2.95%.
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Shigeru TADANO, Masahiro TODOH, Atushi TAKEYAMA
Article type: Article
Session ID: 1133
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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It is very important to understand the mechanical function of spinal cord for therapeutic improvement or pathologic elucidation. Spinal cord is a biphasic substance composed of solid and liquid phases. When it deforms, liquid phase in the tissue flows out through between solid phases. The interaction between two phases derives the macroscopic viscoelastic behavior. An experimental equipment was developed to measure biphasic behavior using a porous metal in the bottom of specimen to flow liquid phase. Stress-relaxation test was done in the confined compression. As a result, gray matter is more rigid than white matter. In relaxation stage, an equilibrium stress in air was higher than in saline. The permeability equation of tissue was determined by applying the biphasic continuum theory. 3D FE analysis of cervical spinal cord was performed for cervical spine fracture. It was confirmed that the stress distribution of internal points in spinal cord was changed rapidly and decreased gradually according to relaxation time.
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Shouji KUZUKAMI, Osamu KUWAZURU, Nobuhiro YOSHIKAWA
Article type: Article
Session ID: 1134
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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We propose a highly efficient identification method to measure a three-dimensional displacement field within a biological soft tissue, which is deformed by a material testing machine. Use is made of the full-field digital image correlation method in line with the Levenberg-Marquardt method to identify the displacement from the three-dimensional X-ray CT images. To realize linearly proportional computation time with respect to the number of degrees of freedom, we reduce the procedure to construct the governing equation by using the numerical symmetry of the coefficient matrix and the locality of basis functions. Moreover, we discuss the requirements for stable and accurate identification, since the X-ray CT images hardly have enough contrast in its intensity distribution to identify the whole material points, and propose a stabilizing formulation using the incompressibility of the materials. Numerical examples concerning pure translational or rotational displacement fields, which are artificially given, demonstrate the validity of the proposed method.
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Takamichi MATSUO, Go YAMAKO, Masayuki ITO, Kunihiko TOKUNAGA, Toshiaki ...
Article type: Article
Session ID: 1135
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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In revision hip surgery, a transtrochanteric surgical procedure using a special designed trochanteric fixation device to make secure is widely accepted, even by orthopaedic surgeons who do not routinely divide the trochanter. However, optimal secured rate by the fixator was noted to be difficult, particularly in aged patients. The purpose of this study was to evaluate the optimally initial fixation with the device using the contact pressure distribution between the osteomized surfaces. It is shown from the experiments that careful preoperation planning to decide wiring location is an important factor in achieving a successful result.
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Kazuhiko SASAGAWA, Hisayuki YAJIMA
Article type: Article
Session ID: 1136
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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A sit-ski is used by the disabled person in a sitting posture. Bi-ski and mono-ski are a kind of the sit-skis. The sit-ski generally known in the Paralympics is mono-ski. While the mono-ski is for personal use, the bi-ski is for general use. The seat shape of the bi-ski, therefore, is simple compared with that of mono-ski. If the sitting position is kept on bi-ski seat for a long time, pressure ulcer may develop in buttocks. However the study on measurement of contact pressure distribution between the bi-ski seat and buttocks has not been done so far and there is no standard of pressure ulcer prevention. In this research, the measurement of contact pressure distribution at an interface between buttocks and bi-ski seat during skiing was realiged dynamically and quantitatively by the wireless pressure measurement system utilizing the pressure sensitive conductive rubber (PSCR) sensor. Pressure loading pattern and pressure value when going on bi-ski were actually measured for a paraplegic person.
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Jiro SAKAMOTO, Yoshimi OMURA, Hideo TAKATA, Tamon KABATA, Juhachi ODA, ...
Article type: Article
Session ID: 1137
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Femoral resurfacing implantation is alternative option to total hip replacement for the surgery of femoral head osteonecrosis. Although it was developed first in the 1970s, it did not come into wide use because postoperative stability was not sufficient for a long period. Femoral resurfacing implantation has been attracted the attention of orthopedic surgeon again, since material and design technology has been recently progressed. In this study, finite-element models of femoral head replacement with the resurfacing implantation were created based on a clinical CT images, and stress analyses were carried out considering inhomogeneous property of bone. Furthermore, influence of stress distribution around die femoral head with arrangement of the resurfacing implantation was investigated by changing position of the implantation. Validity of implant angle in usual surgery was discussed by the analyses.
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Yasushi AKAZAWA, Hisashi NAITO, Takeshi MATSUMOTO, Masao TANAKA
Article type: Article
Session ID: 1138
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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An ankle-foot orthosis (AFO) is a primal aid for patients with gait disorder, and the mechanical characteristics of AFO joint directly affect the walking function. In this article, considered are the necessity of AFO joint characteristics changing automatically during a gait cycle and the control scheme of such an AFO joint so that the wearers can train/reorganize their orthotic gaits towards the goals designated by their own physiotherapists in relief/safety. A teaching-playback scheme is employed, and the initial joint characteristics are determined for each of the swing phase, the initial stance phase and the mid-terminal stance. We prototyped an intelligent AFO with gait pattern sensors and a controller adjusting the magnet position for MR-fluid brake.
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Chikako IKEDA, Shuichi WAKAYAMA, Junji IKEDA
Article type: Article
Session ID: 1139
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Microdamages during four point bending proof tests were monitored by AE technique, and residual strengths of specimens which survived proof tests were investigated. Two AE behaviors, with and without increasing point of AE energy, were observed in proof tests. Specimens without increasing point of AE energy had higher residual strengths than specimens with increasing point of AE energy. AE source locations during proof tests and residual strength measurements demonstrated that the microcrack formed during proof tests were propagated to final unstable fracture during residual strength tests. Consequently, it was understood that proof test with AE technique which could detect microdamages during proof test insured higher reliability than proof test without AE technique.
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Shimpei KOHRI, Tsutomu TAJIKAWA, Kenkichi OHBA
Article type: Article
Session ID: 1140
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Blood flow is influenced by blood pressure, geometric configurations of blood vessel, characteristics of blood itself and so on. Measurement of local blood velocity may be useful in evaluating the properties of blood flow and finding out vascular lesions. In order to measure the local blood velocity, an optical fiber LDV (Laser Doppler Velocimetry) sensor was developed. By chemical etching with a HF-NH_4F buffer solution, a convex lens-like surface was formed on the fiber tip. Laser beam emitted from the fiber tip was focused about 200μm ahead of the tip, where the measuring point was formed. The chemical etched fiber was inserted through a needle into an acrylie resin rube and used as a sensor for pulsatile flow velocity measurement of bovine blood As a result, the local blood velocity of pulsatile flow was successfully measured by this optical fiber LDV sensor.
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Takumi KAWANA, Takeo YAGI, Takatoshi UMENO, Toshiaki HARA
Article type: Article
Session ID: 1142
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Although the seriously radiation injury to both patients and surgeons through the detection of the hole under osteosynthesis using interlocking nailing has been noted in some papers, the clinical results generally have been good. We have developed a new designed intramedullary rod with a small slot and the effectively ultrasonic detection technique for an interlocking hole while the improved detection procedure to relieve this injury is described as technically difficult. The goal of this paper is to present the optimal design of intramedullary nailing using FEM analysis and to describe the effect of the factors that are likely to result in success or failure.
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Takeo YAGI, Takumi KAWANA, Takatoshi UMENO, Masafumi ODA, Toshiaki HAR ...
Article type: Article
Session ID: 1143
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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The clinical results for osteosynthesis using interlocking nailing generally have been good. However, the rate of radiation injury during the detection of nail hole has been noted to be seriously high, particularly in both of orthopedists and patients. We developed the ultrasonic technique to detect the distal nail hole and to relieve the radiation injury. The qualitative results were that technical experience and careful manipulation of probe are important factors in achieving a successful result.
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Kouhei MURASE, Hiroshi YAMADA
Article type: Article
Session ID: 1144
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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A technique of motion capturing using digital video (DV) cameras was proposed to measure the time dependent changes of human posture. This system was consisted of several couples of the DV networking unit which transfer the image frames, the shape extractors and the reconstruction server. The result of applicated test in the manufacturing cell, included material handlings, machining center and some instruments, the targets which put on the working uniform were able to captured. The result of calibration measurement indicated the system has good ability of spatial recognition when a couple of unit has 20 degree and 400mm distance from target.
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Juhachi ODA, Hiroki TAKADA
Article type: Article
Session ID: 1159
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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It is hard to use the drill by bare-handed. We want to develop machine that the vibration or impact was suppressed. A woodpecker is enumerated as for repeatedly an impact. A woodpecker strikes its beak toward a tree repeatedly. But, the damage of the brain or the living body doesn't occur by this action. Therefore, it is predicted that the brain and body of woodpecker is protected from the shock by some methods. And it turns out that the woodpecker has the original mechanism that endures impact. In this study, from the structure of woodpecker (especially hyoid bone) makes a model. And the model is analyzed. It thinks about the endures impact from the result.
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Kazunori FURUKAWA, Sota YAMAMOTO, Koji MIZUNO, Eiichi TANAKA, Isao WAT ...
Article type: Article
Session ID: 1160
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Bending test of piglet femur bones and specimens of 2.5mm×2.5mm×46mm from the bones were done using Instron universal materials testing machine to obtain the substitute data of human child biomaterial property which is indispensable to child finite element model with high bio-fidelity. The results indicated the correlation coefficients between bending strength and femur length and between elastic modulus and femur length were 0.85 and 0.79 respectively.
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Kouhei MURASE, Hiroshi YAMADA
Article type: Article
Session ID: 1161
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Human joints are subjected to dynamic or impact loading in life. However, conventional biomechanical research of human joints have been concerned principally to static loading condition. The purpose of this study was to investigate the mechanism of stress evolution through cancellous bone in knee joint. In this study, the human knee joint FE models which were consisted of hexahedoral finite elements were prepared and were applied impact loading. As the result, the number of element by the hexahedral meshing is less than a quarter of that by the tetrahedral one.
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Article type: Appendix
Pages
App4-
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Masao WATARI, Sigeru AOMURA, Satoshi Fujiwara, Akiyosi Nishimura
Article type: Article
Session ID: 1163
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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When man received dull External Injury on a head and died, generally Skull Fracture, Intracranial Haematoma, Arachnoid mater Haematoma, Brain Damage, etc. is the cause of death. Particularly, we call the local brain damage produced on the brain surface of the side which received the blow coup contusion, and without knowing why some which damage produces are in the opposite side of the shock part which has not received the direct blow. It calls contrecoup contusion. But, these are very difficult to judge what kind of shock received from the dissection view from the head. Then, it refers to the data of the easy shock experiment and past this time, and elucidation of head injury is advanced.
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Shinobu SAKAI, Juhachi ODA, Kengo KAWATA
Article type: Article
Session ID: 1164
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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The most common commercial pitching machines for baseball are the "roller" type and also the "arm" type. The pitching, such as the fast, curve and sinking ball, is easily achieved by the roller type. In this study, a moving behavior and a contact stress state of the pitched ball with the roller type pitching machine is analyzed using the dynamic FEM analysis software (ANSYS/LS-DYNA). In addition, the initial velocity and the spin of the pitched ball are filmed using a high-speed videography, and those pictures compared with the FEM analysis. Furthermore, a model of the ball with a seam is analyzed, and those influence is considered.
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Suguru YOKOSAWA, Sigeo WADA, Ken-ichi TSUBOTA, Haruo ISODA, Hiroyasu T ...
Article type: Article
Session ID: 1201
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Blood flow in the aorta is complex, being affected by both the geometry of the aorta and flow dynamics stemmed from the left ventricle. It has been suggested that such a complex flow plays an important role in the localization of vascular diseases such as aortic aneuysm and arteriosclerosis. The aim of this study is to investigate the effect of the inflow and geometry of the aorta on the aortic flow. We measured the velocity profile at a site just above the aortic valve using cine phase contrast MRI (PC-MRI), and then performed CFD analysis of blood flow in the aorta using the measured velocity as an inlet boundary condition. The results showed that the geometry of the aorta is influential in the hemodynamics in the whole region of the aorta while the effect of the aortic inflow remains up to the aortic arch.
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Hideo YOKOTA, Masaomi NISHIMURA, Sakiko NAKAMURA, Kazuaki FUKASAKU, Ak ...
Article type: Article
Session ID: 1202
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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[in Japanese]
Article type: Article
Session ID: 1203
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Noriyuki FUJITA, Shigeru AOMURA, Satoshi FUJIWARA
Article type: Article
Session ID: 1204
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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In this study, the relation between various impact loadings and intracranial pressure of a human head model is studied. Firstly the pressure response of sealed acrylic water container under impact loading is obtained experimentally and by FEM, and both results are compared. After verifying the numerical method, the various impact loadings are given on the 3D finite element human head model. Under the condition of constant energy impact, the velocity gives more influence than the mass on the intracranial response. Stroke of high speed/small mass causes vibration of skull with rather high frequency and stroke of low speed/large mass causes positive pressure on impact side and negative pressure on the opposite side of the impact and does not cause vibration. If brain cells are damaged by negative pressure, this result would agree with the following theory by legal medicine: Stroke with short time duration tends to cause both coup and contrecoup contusion simultaneously, on the other hand stroke by fall down tends to cause contrecoup contusion.
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Daisuke TAWARA, Jiro SAKAMOTO, Atsushi SEKIMOTO, Hideki MURAKAMI, Nori ...
Article type: Article
Session ID: 1205
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Osteoporosis causes frequently bone compressive fracture at the vertebrae as a representative complication. To strengthen osteoporosis vertebra, drug therapy are often treated in clinic. It is important to evaluate mechanical strength and betterment of bone fracture risk of vertebra in this treatment process. To estimate them noninvasively in detail, patient-specific mechanical analysis is necessary because mechanical strength of vertebra depends on patient-specific factors, which are shape, cortical thickness, density distribution of cancellous, and so on. In our previous study, finite-element (FE) models derived from CT images gave us good prediction of vertebral strength, and effect of treatment was demonstrated clearly. In this study, FE analysis for predicting force value occurring bone fracture of 4 osteoporosis vertebrae was also performed following drug treatment process over time. Availability of evaluation method of vertebral strength using bone fracture analysis was discussed.
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Mizuho Tanaka, Toshiro Matsumoto, Masato Baba, Shouichi Miyawaki, Tets ...
Article type: Article
Session ID: 1206
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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The purpose of this study is to investigate stress distributions of the mandibular fossa and condyle about the human temporomandibular joint (TMJ) with and without anterior disc displacement by three dimensional finite element method (FEM). The following results were obtained that the stress distributions at anterior mandibular head were larger than posterior in the case of normal temporomandibular joint. In the case of anterior disk displacement of the left TMJ, the stress distributions at anterior mandibular head were larger than posterior and it was larger than normal temporomandibular joint.
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Michihiko KOSEKI, Norio INOU, Koutarou MAKI
Article type: Article
Session ID: 1207
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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This study proposes an estimation method of the masticatory forces using an objective function composed of three criteria: efficiency of muscular activities, moment balance between muscular and biting forces, and reaction forces at condyles. Our previous study applied the method to a patient whose jaw had a severe deformity, and showed validity of the method. This paper applies the method to a patient with a symmetrical jaw. The numerical result shows an unrealistic masticatory condition, such as there are non-working muscles. The plausible solution of this problem is discussed.
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Shinpei SATO, Michihiko KOSEKI, Hitoshi KIMURA, Norio INOU, Koutarou M ...
Article type: Article
Session ID: 1208
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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It is expected to develop an intelligible diagnostic system of temporomandibular disorders (TMD) for both medical doctors and patients. Our proposed display system visualizes motion of the human mandible. The system integrates two engineering methods. One is an optical motion capture technique for measuring the mandibular movements. The other is an individual modeling method based on the x-ray CT data. This study demonstrates visualization of the human mandibular motion in mastication with the display system.
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Hiroki TERADA, Yousuke MURANAGA, Kazumi TOYODA, Kazuto TAKASHIMA, Kiyo ...
Article type: Article
Session ID: 1209
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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In minimally invasive intravascular interventions with the aid of catheters, it is necessary to incorporate a detecting system of the probe during all the time of operation. To this end, the standard X-ray imaging is used in the most cases. However, a high radiation dose caused by X-ray is an important health risk for clinicians and patients. In order to reduce the radiation dose, new navigation systems that replace or reduce the use of X-ray imaging must be developed. We have developed a system composed of Magneto-Impedance(MI) sensors outside the patient, and a magnet on the tip of the catheter. It is considered that the effect of the magnetic field on the human body is low. But our system is not still enough to use for the practical interventions because of the narrowness of detecting area and the noises. In this study, we proposed movable sensor system and simulated it.
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Hisashi HAYASHI, Toshimitu HIRAI, Kiichi TUJI, Hiroyuki MIYAGAWA, Ryou ...
Article type: Article
Session ID: 1210
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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This paper describes the development of device that can detect effective treatment point for laser stimulation quickly and easily. The effect of the relaxation can be achieved by irradiating the laser to a specific acupuncture point. However, it was not effective because the method of detecting the acupuncture point was difficult in the past. As for the method for the easy detection of the specific acupuncture point, it was reported that there are an electric impedance method and an acoustic method. However, the method of detecting these was not effective enough. Therefore, it is necessary to investigate an electric characteristic of the acupuncture point more in detail.
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Taku TAKASHINA, Naotaka SAKAI, Satoshi SHIMAWAKI
Article type: Article
Session ID: 1211
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Quantitative sensory testing of the thermal sense has not been established on the site of the medical treatment and rehabilitation now. In this research, we developed thermal stimulator with peltier module which allowed to control stimulus temperature by PID control in high accuracy, and examined the distribution of the thermal perception on the human hand. We used this and experimented on the hand palm side of the dominant hand to the part of 29 which considered the rule area of the nerve. Ten subjects(21-23 year old men) participated in this study. The part where the thermal sense was sensitive was developed by the experiment, and the perception distribution of the temperature was discovered. Cold stimulus threshold on proximal phalanx was lower than distal phalanx that on significantly (P<0.05).
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Matsunori NARA
Article type: Article
Session ID: 1212
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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The following conclusions were able to be obtained as a result of experimenting for the purpose of clarifying the optimal operation conditions for producing a lipid bilayer (liposome) by being made from phosphatide by using the supercritical fluid of carbon dioxide, and moving the produced liposome in the arbitrary directions, 1) In order to obtain the small liposome of particle diameter, pressure was heightened at the temperature near a critical point, for example, the conditions of 35 degrees C and 12MPa were the optimal. 2) This was able to be driven by applying induced electromotive force to the liposome which made titanium oxide hold.
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Yu Moriwaki, Nobuo Sakai, Yoshinori Sawae, Teruo Murakami
Article type: Article
Session ID: 1213
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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The human elbow joint has two degree of freedom. Especially, wide range for the rotation of the forearm (pronation - supination) is attained, because of the sophisticated complexity of the human elbow joint. The elucidation of its mechanism is useful for medical evaluation and application to welfare devices. The purpose of the study is to develop the arm model that imitates the musculo -skeletal system of human elbow joint. In this paper, we made a simplified physical model with a bionic elbow joint and evaluated the mobility of the arm model by the moment arm.
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Takeshi SHIMOTO, Hidehiko HIGAKI, Masa-aki YOSHIZUMI, Satoshi HAMAI, Y ...
Article type: Article
Session ID: 1214
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Painful and crippling knee conditions are completely released by total knee arthroplasty (TKA). However, wear of polyethylene insert frequently shortens the life span of TKA. Because knee movement involves a complicated combination of translations and rotations. Therefore, adequate motion analysis is necessary for estimating the wear of inserts and improving the design of artificial knee joint. This study was aimed to develop a three dimensional motion analysis for artificial knee joint with high precision by using image matching technique with high-resolutional flat panel detector (FPD). The image matching was to overlap the actual FPD image and the reconstructed image. In this report, we analyzed knee prostheses during walking motion using this motion analysis method. It was possible to reproduce the in vivo relation between a femoral component and polyethylene insert. Additionaly, motion analysis of artificial knee implants could clarify typical motion pattern depending on patients.
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Kazuto TAKASHIMA, Takayuki KITOU, Koji MORI, Ken IKEUCHI
Article type: Article
Session ID: 1215
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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In the treatments using stents, there is a problem known as neointimal hyperplasia. One of many possible theories postulating the causes of inthnal hyperplasia is the stress concentration at the contact area of the arterial wall with the stents. Therefore, we investigated the stress distribution at the contact area between the stent and the artery. We used two artery models; one is plane and another has a plaque, and two kinds of link stents with different circumferential numbers of the cells and the links. Firstly, we investigated the contact condition by finite element method. Secondly, we carried out the experimental visualization of the contact area to examine the validity of the simulation. It was proved that the stress distribution of the arterial wall is affected by the structure of the stents and the experimental distribution was similar to the calculated one.
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Hideki IZUMIDA, Koji MORI, Takashi SAITO, Kazuto TAKASHIMA, Ken IKEUCH ...
Article type: Article
Session ID: 1216
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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High radial stiffness and longitudinal flexibility are essential mechanical properties of a stent. These mechanical properties depend on stent structures and dimension. A stent is composed of a cell and a link. We calculated effect of design factor on stent structures. The objective of this paper was to investigate the influence between longitudinal lengths of a cell (A) and a link (B) and these mechanical properties using compression test machine. The results showed that the radial stiffness increased with the cell-link length ratio (B/A). Radial stiffness is independent of compression position.
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Kaori Kuribayashi, Koichi Tsuchiya, You Zhong
Article type: Article
Session ID: 1217
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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This paper describes a new type of an innovative stent graft using Ni-rich Titanium/Nickel (TiNi) shape memory alloy (SMA) sheet. Unlike the conventional stent grafts which consist of a wire mesh stent and a covering membrane, our new stent graft can be made a single folded sheet. Folding of the new stent graft is achieved by dividing a cylindrical tube into a series of identical elements with hill and valley folds as in origami (Japanese art of paper folding). To produce the stent graft which can be expanded at body temperature, the Ni-rich TiNi SMA sheet made by newly developed ultra fine laminates method was used. The pattern of folds on the sheet was produced by negative photochemical etching. A number of prototypes of the stent graft, which are the same size as standard oesophageal and aortal stent grafts, have been produced successfully. It has been demonstrated that the stent graft deployed smoothly and gradually at a near body temperature.
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Miwako IKEDA, Tomokazu MUKAI, Noriaki SHIRAHAMA, Kazuo TAKAKUDA
Article type: Article
Session ID: 1218
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Tubes for guided peripheral nerve regeneration are highly expected to be the substitutes for nerve transplants. These tubes must be designed to provide the flexibility, kink resistance and compression resistance because these functions help nerve regeneration. Cylinder tube we first design being less kink resistance, flexibility, not easy to operate, the shapes of tubes must be renewed. Hence, we invent bellows tubes expected to have more suitable characteristics. In this paper, using finite element method, physical characteristics in compression and bending test of tubes are calculated and optimum shapes are considered. Outputs indicate that bellows tubes have more than twice as compression and kink resistance as cylinder tubes have.
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Shinichi GOMITA, Takuji KOIKE, Kyoji HOMMA, Sayuri MURAKAMI, Toshimits ...
Article type: Article
Session ID: 1219
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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This paper deals with analysis of the dynamic behavior of the patulous Eustachian tube. Three-dimensional finite element method is used in this study to model the human Eustachian tube. Dynamic behavior of the patulous Eustachian tube caused by sniff was analyzed. Pressure distribution in the Eustachian tube was first obtained and was found to be roughly uniform all over the Eustachian tube. Then, the deformation of the patulous Eustachian tube was analyzed by applying the uniform pressure to the lumen of the Eustachian tube. As a result, the Eustachian tube started to close at its narrowest portion, and the area of occlusion expanded toward the pharyngeal orifice.
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
Session ID: 1220
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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The morbidity of osteonecrosis of the femoral head (ION) has grown rapidly. An essential ION treatment is to prevent collapse of a degeneration site on femoral head with necro-cytosis. The biomechanical degeneration of trabecular bone structures has been few documented while regenerating processes of bone tissue and fibrous tissue have been shown to lead the structural degeneration. The purpose of this study was to evaluate the relationship between the trabecular architecture and the degree of mineralization of bone (DMB) using micro-CT image data in the necro-cytosis area. ION was surgically induced in the left femoral head of Wistar rat which were analyzed by morphometric evaluation data and DMB parameters after 1,3,6 weeks postoperation. We conclude that significant increasing in bone volume (BV/TV) and trabecular thickness (Tb.Th) after ION may lead to an increase in the structural and mechanical strength. This suggests that bone tissues after ION may regenerate by pathological bone repair, so called additional bone formation, and that there is still necrotic-cytes tissue.
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Kazuki TAKAHASHI, Takatoshi UMENO, Toshiaki HARA
Article type: Article
Session ID: 1221
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Rapid Prototyping (RP) technique is widely used to industrial and medical products including biomedical instruments. The clinical applications of the RP technique to model surgery are reported more favorably in some papers. However, the model dimensions with high precision have been described as technically difficult. In this paper, we developed the bone biomechanical experiments using three dimensionally acrylic and trabecular resin model from Computed-Tomography data to evaluate the applicability of the RP technique to bone fracture estimation. The results show that careful preoperative planning and experience are important factors in achieving successful results.
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Yuichi SHOYAMA, Ryosuke MATSUMOTO, Michihiko NAKAGAKI
Article type: Article
Session ID: 1222
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Junpei MATSUDA, Kosaku KURATA, Takanobu FUKUNAGA, Hidehiko HIGAKI
Article type: Article
Session ID: 1223
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Microgravity induces osteoporosis. Osteocytes are considered to act as a mechanosensor in bone tissue. They are the most abundant cells in bone and distribute throughout the bone matrix. However, very little is known about detail mechanism of osteoporosis occurred under microgravity. We have already reported that microgravity influenced cell proliferation, cell-to-cell communication and differentiation of bone marrow cells when osteocyte-like cell line MLO-Y4 cells were cultured in monolayer and subjected to multi-dimensional gravity. However, osteocytes in vivo were deep embedded in bone matrix. Therefore, the aim of this study was to examine the effects of multi-dimensional gravity on osteocytes in three-dimensional culture. MLO-Y4 cells were cultured in type I collagen gel, and then exposed to multi-dimensional gravity for 24h. Double fluorescence staining technique revealed that cell-to-cell communications via gap junction were significantly decreased in multi-dimensional gravity. Bone marrow cells were cultured for a week with using conditioned medium (CM) obtained from osteocyte culture under multidimensional gravity. TRAP (tartrate-resistant acid phosphatase) activity was significantly increased by adding CM from osteocyte culture exposed to multi-dimensional gravity.
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Yoshinori KOYAMA, Taiji ADACHI, Yoshihiro TOMITA
Article type: Article
Session ID: 1224
Published: September 18, 2005
Released on J-STAGE: August 01, 2017
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Regeneration and remodeling processes of trabecular bone structure in cancellous bone defects are affected by various factors. Basic understanding of the bone regeneration mechanism will help us to design artificial joints, implants and scaffold microstructure for bone tissue regeneration. In this study, artificial defect was created in cancellous bone region of a rat distal femur, and a formation mechanism of trabecular structure in the defect was evaluated using X-ray μCT and microscopy. As a result, it was revealed that the directionality of defect did not directly influence on the formation of bone structure, while the defect shape have remarkable influence on the bone matrix formation.
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