In the clinical, it is difficult to carry out the motion analysis because it requires a large place. The purpose of this study is to examine the gait analysis method by one direction frontal video that can be easily measured in clinical. The subjects were five healthy persons attached four markers at both shoulders and both anterior superior iliac spine (ASIS). The walking motion of each subject toward a camera was analyzed. Body trunk tilt and centroid sway of the upper body part were calculated and compared with the results of three-dimensional gait analysis methods. The result showed the same tendency of the body trunk tilt and the centroid sway changes based on each method. The result suggested that the gait analysis by one direction frontal video could evaluate the large abnormal gait. Further, authors evaluated OA knee joint thrust using one direction frontal video. The change of the knee joint alignment and the distance between the loading axis of lower extremity and knee joint center were calculated as knee joint thrust. Results showed that knee adduction angle and distance of knee joint center from lower limb loading axis of OA patient were increased. The result suggested that this method could evaluate the knee joint thrust of OA patient.

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　　　Micro computed tomography (Micro CT) is an imaging technique widely used for visualizing the internal structure of objects using the x-ray attenuation method. As it enables non-destructive, noninvasive evaluation and three-dimensional analysis, it is useful for various studies of human hard tissues. Most hypophosphatasia cases exhibit early loss of primary teeth, however findings of Micro CT analysis of them have not been reported. The purpose of the present study was to describe the mineral density distribution of exfoliated teeth with hypophosphatasia using Micro CT. Each two exfoliated teeth of mandibular primary central incisors gained from 2 hypophosphatasia patients were investigated for enamel and dentin mineral densities. Mineral density distribution revealed that the case 1 were lower than the homonymous teeth case 2 in the region of enamel edge in enamel and dentinoenamel junction in dentin. These results suggested that hypophosphatasia patients had the variety of hypomineralization in the primary dentition. The investigations using Micro CT is useful for various studies of human hard tissues gained from patients since it enables non-destructive, noninvasive evaluation.

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　　　The posterior cruciate ligament (PCL) functions as the primary restraint to posterior tibial movement and the stabilizer for axial rotation of the knee joint. It is, therefore, important to know the mechanical characteristics of the PCL. The objective of this study was to evaluate the in vivo characteristics of the three-dimensional (3D) deformation and orientation of the PCL during knee flexion using magnetic resonance imaging (MRI). Ten normal knees were visualized using MRI at full extension (FE), 10°, 20°, 30° and 60° of static knee flexion. The length, strain, elevation and deviation of the PCL were measured using the 3D models of the femur, tibia and PCL reconstructed from the MR images. The PCL length was measured in three portions (Medial: M, Central: C, Lateral: L) to consider its 3D shape. Tendencies of the PCL elongation and strain during knee flexion were different among these 3 portions. The PCL length in M portion was shortest in 10° or 20° and extended in FE and 60°. The PCL length in L portion, on the other hand, extended from FE to 60°. These 3D deformation characteristics were consisted with the changes in the elevation and deviation of the PCL during knee flexion.

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　　　The purpose of this study was to develop a method for evaluation of the three-dimensional (3D) alignment and position of the artificial knee joint using a biplanar slot radiography (SR) system and 3D models. A SR system uses collimated fan beam x-rays synchronized with the movement of a flat-panel detector. This system allows to obtain a full length x-ray image of the body with reduced dose and smaller image distortion compared with conventional x-ray systems. The biplanar SR system used a rotation table positioned at 0 deg and 60 deg relative to the optical axis of an X-ray source. Camera calibration was performed using an acrylic frame with 72 radiopaque markers. The femoral and tibial components of a total knee replacement system were immobilized and imaged using the biplanar SR system. Then, the femoral component was installed on a sawbone femur and imaged again. The 3D positions of the components and femur were recovered using an interactive 2D to 3D image registration method. Overall, the largest estimation errors were within 1 mm in translation and 1 deg in rotation, demonstrating that this method has an adequate accuracy for the clinical usage.

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　　　Postmenopausal osteoporosis results from an increase in activation frequency and an imbalance between bone formation and resorption. Osteoporosis is a skeletal disorder characterized by compromised bone strength that predisposes an individual to an increased risk of fracture. We investigated the bones of rats with osteoporosis induced by ovariectomy. Female Sprague-Dawley rats (12 weeks old) were subjected to ovariectomy or a sham-ovariectomy operation. Images of tibial metaphysis were obtained using a micro-computed tomography (micro-CT) scanner, and were subjected to subsequent analyses. Three-dimensional (3D) data were obtained by constructing sliced images along the bone axis and evaluated using an image analyzer. Histological assessment was performed to confirm the bone structure and pathological observation of the obtained image. The micro-CT results of parameter analysis showed decreased bone mass and deterioration in the structural properties critical to the mechanical strength of osteoporotic bone. In conclusion, 3D-CT imaging provides an accurate noninvasive method for directly measuring bone architecture. Micro-CT imaging of small animals allows the evaluation of bone morphology and micro-architecture in animal models, such as bone loss induced by estrogen deficiency.

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　　　Plastic ankle-foot orthoses (PAFOs) are often used as assistive devices for patients with hemiplegia. In this study, force exerted on PAFOs during walking was measured using a sensor installed at the top of the calf region on the PAFO, where the structure of the PAFO exerts minimal influence on measurements, and the data were analyzed. First, PAFOs with incorporated sensors were individually prepared for 3 healthy individuals and for 3 patients with hemiplegia. Mechanical data were then obtained while individuals wore the PAFOs during level-ground walking. We found that at the early stance phase, force vectors apply at a slightly lower region of the prosthetic rear wall, the level of which is the same as the upper belt, and at the late stance phase, they usually apply at the upper belt region. We also found that the waveform of posterior force applied by the PAFOs coincide with that of the bending angle of the PAFOs. From these findings, we found that the approximate posterior direction force applied by the PAFOs, which usually must be measured using costly sensors and modified PAFOs, can be easily estimated by measuring and calculating from PAFO bending angle.

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　　　Cell movement plays an essential role in embryonic development, wound healing in multicellular organisms and cancer metastatis. It is known to be a cyclic system of the protrusion at the leading edge, adhesion to the extracellular matrix via focal adhesions and detachment and retraction at the cell rear. Focal adhesions are one of the key players for cell movement. However, in case of HT1080 fibrosarcoma cell which is one of the cancer cells, although mechaism of invasion to the extracellular matrix has been extensively studied, mechanism of adhesion to the extracellular matrix via focal adhesions has not been well understood. In this study, therefore, an attemp was made to visualize and analyze the distribution of focal adhesions in HT1080 fibrosarcoma cells expressing RFP-zyxin and GFP-actin by laser confocal microscopy. As a result, during movement of HT1080 fibrosarcoma cell, focal adhesions appeared at the region of protrusion whereas they disappeared or remained at the region of retraction, which led to the asymmetric distribution of focal adhesions in the cell. On the other hand, when a cell showed staying behavior during movement, focal adhesions equally distributed close to the edge of the cell.

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　　　The measurement accuracy and the spatial resolution of displacements and strains by digital image correlation method (DIC) is investigated. Displacements of the in-plane rigid body rotation are measured by DIC using various subset sizes. Displacement gradients are calculated using local least squares method with various gage lengths. Standard deviations of the measured displacement error and the displacement gradients are evaluated. As a result, it is found that the standard deviations of the displacement error and the displacement gradient are affected not only by the subset size and gage length but also by the measurement displacement gradient.

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　　　Since the classical investigation of the Taylor vortex by G. I. Taylor in 1923, many researchers have studied the Taylor vortex as one of the most important vortex types in flow. In this study, the inner cylinder is rotating, while the outer cylinder, which is concentric with the inner cylinder, is stationary. The phenomenon is visualized experimentally as a three-dimensional problem. In addition, the measurement of the velocity distribution is carried out by the PIV method. The radius of the inner cylinder is 20 mm, and that of the outer cylinder is 30 mm. The gap between the inner and outer cylinders is 10 mm. In this study, Re = 650 - 1200 is assumed. The aspect ratio Γ is defined as the ratio of cylinder height to gap distance. A servo motor to rotate the inner cylinder, a servo- motor control device, a servo amplifier for rotation speed control, and a YAG laser light source are installed in the apparatus. As tracer particles used in the PIV method, fluorescent particles with a size of 15 micro meters were used. The results of EFD and CFD are compared. The mode bifurcation is observed, and the flow structure is investigated. PIV and EFD results show good agreement quantitatively including extra vortices which are difficult to observe in PIV. This PIV system can analyze unsteady flows like Twin-cell mode, and it is useful to analyze time-dependent flow bifurcation.

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　　　It is of practical importance to develop an inexpensive and reliable measurement method for mixing time in a cylindrical bath agitated by bottom gas injection. The thermocouple-based method was chosen in this water model study. Hot water was used as tracer and introduced from the surface of a water bath subjected to air injection from a single-hole bottom nozzle. The mixing time was determined on the basis of the history of the temperature of water in the bath. This method was found to be satisfactorily applicable to mixing time measurement in a bottom blown bath.

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