We have studied flow induced flutter vibration of co-rotating two disks by using LDV. It is found that the arm which is inserted between two disks suppresses the disk flutter vibration. In addition, we have also measured pressure as well as air flow velocity distribution between two disks by using the pressure sensor and the hot-wire anemometer. From the experimental results, it is found that the mean flow velocity decreases and its distribution is more uniform, while the circumferential variation of the mean static pressure and the RMS static pressure fluctuation decreases, when the arm is inserted between two disks. Therefore, it is suggested that there is the correlation among the disk flutter vibration, the circumferential variation of the mean static pressure and the pressure fluctuation between two disks, and the disk flutter can be suppressed by inserting the arm or spoiler that decreases the pressure fluctuation between two disks.

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It is important to clarify air flow induced vibration issues for hard disk drives in order to achieve ultra-high magnetic recording density. We studied flow induced flutter vibration in actual 2.5 inch HDD which has one disk and two magnetic heads. In this study, the disk flutter vibration as well as static pressure distribution between the top cover and disk were measured, changing the magnetic head slider track following modes as well as the seek modes. From these experimental results, it was found that the disk flutter amplitude increases and its frequency decreases, when the magnetic head is operating on a disk. We also found that the mean pressure distributions was changed under various head operating conditions. As a result, it suggests that a disk flutter amplitude increase is due to the change of mean pressure distributions and disk flutter frequency decrease is caused by the effect of head-disk coupling vibration system.

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The accuracy of reference position signals in hard disk drives is discussed. Servo patterns, which are used for reference position signals, are written by a manufacturing-equipment called servo track writer (STW). Recently, various methods for STWs are investigated to achieve narrower track widths and more accurate track shapes. One method is based on semi-closed head-positioning control, and another is on full-closed one. In this paper, positioning disturbances caused by disk flutter are modeled in order to analyze writing accuracies with bank-write method. In bank write condition, vector locus diagram is useful to evaluate servo pattern accuracies, especially, by the STWs based on full-closed head-positioning control.

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Reducing windage, or flow-induced vibration of the head slider in the off track direction, is a very important issue in increasing the track density of hard disk drives (HDDs). We examine the characteristics of windage in this paper with the goal of enabling development of head gimbal assemblies (HGAs) with smaller windage. We used a 12-mm-long (from the swage hole center to the dimple) HGA in our study. An HGA was set between a rotating disk and a wall, and its windage was measured with a laser Doppler vibrometer. The results showed the windage amplitude correlated well with the mean airflow velocity. We concluded that reducing the air flow velocity is very useful in decreasing the windage amplitude.

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That a narrow gap between a disk and a shroud reduces disk flutter amplitude is one of the most important knowledge on disk flutter of hard disk drives. This has been explained by reduction of an airflow excitation because of blockage of a vertical flow from a side of the disk to the other side. However, we found a different phenomenon in our experiments: damping ratios of the disk flutter were increased but the mode excitations were not reduced by a narrow disk-shroud gap. In the experiments, frequency spectrums of disk flutter were measured for various disk-shroud gaps. The frequency spectrum for the narrow gap showed more rounded peaks than for the wide gap, and the amplitudes of the flat area between the peaks were approximately same in the both cases. We derived its theoretical equations from energy dissipation of a flow induced by disk flutter at a disk-shroud gap, and these equations with reasonable parameters can explain the experimental results very well. So, the mechanism of the aerodynamic damping was confirmed. According to the equations, damping ratios of disk flutter due to the aerodynamic damping are inversely proportional to cube of a disk-shroud spacing normalized by an outer radius of a disk. Considering a constant damping independent on disk-shroud spacing, we can get a relationship between disk flutter amplitude and disk-shroud spacing. This relationship matches the experimental results with various disk sizes that had been reported.

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DVD disc vibration at the critical number of rotations was examined to determine its cause and identify a means of reducing it. Disc vibration at the critical number of rotations is considered the vibration mode of a DVD disc, and the position of this vibration mode is always the same for a DVD drive. The relative inclination between the optical head and disc increases with the vibration. This paper describes the stabilization of the disc in a DVD recording system during high-speed rotation of the disc. The top cover of the drive is equipped with a disc vibration control structure that controls the (0,2)-(0,4) vibration modes of the disc at the critical number of rotations, thereby reducing the relative inclination between the optical head and disc significantly.

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A new objective lens actuator structure for optical disc drives was developed. Three magnets were assembled as a magnetic circuit in the actuator. One magnet is placed in the center of one side of the moving part, and two other magnets are arranged at both ends of the other side of the moving part. This structure can prevent the actuator from rolling along the rolling axis of the moving part. According to the calculation and experimental results, the developed actuator shows that the inclination of the objective lens at the resonance frequency of rolling mode is reduced to 60%, compared with a conventional structure.

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Recently an optical disk server is prospective for demand of the performance of the backup storage system and growing capacity of the optical disk. So we are developing a disk changer for the optical disk server. It was developed for miniaturization assuming that it is used in the server rack. The disk changer consists of a carrier and a lift using crossing links. The carrier has two feeders to shorten the disk absent time from the drive, and the feeder is a reliable mechanism using a simple timing belt. And the changer has a turnout slot that changes a disk place from one side of carrier to another side to prevent the carrier protruding. As a result the changer could be miniaturized to 88mm height with 16disks.

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The front-loading of the simulation rises, and the simulation by which two or more design variables are combined increases in recent years. In the simulation with a change in shape, setting of the mesh making, the boundary condition, and the contact definition, etc. is needed again, and a lot of time is needed for the model the re-making by the shape change. Then, the morphing tool was applied, and improved the efficiency of the simulation by which two or more design variables were treated. In the cellular phone design, the example of applying morphing is introduced.

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This paper presents a new analytical method to determine process parameters on Double exposure Deep X-Ray Lithography (D^2XRL). D^2XRL is a unique and promising technique for 3D micro fabrication among other techniques. As an example, it was demonstrated that a micro-needle array with the very sharp tip is easily and successfully fabricated without any special apparatuses and difficult process control. The advantage of the newly proposed analytical method is that an effective relationship between required shape and process parameters are derived directly from equations. It was successfully demonstrated that the process parameters to fabricate a micro-needle with specific "height" and "tip angle" was possible to be determined by proposed analytical method.

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This paper describes experimental investigation of meniscus force and friction force of a water droplet sliding between two hydrophobic surfaces. A water droplet on a hydrophobic surface generates positive Laplace pressure, which can support the normal load. Friction force between water droplet and hydrophobic surface is small. These characteristics provide the possibility of application to lubrication of micromechanical parts. Meniscus forces, friction forces were measured when a water droplet was sheared between two hydrophobic surfaces and relationship between these forces and shape of the droplet was examined. Moreover, the generation mechanism of the friction force was clarified based on the experimental results.

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Probe oxidation-based surface-nanofabrication has been presented. Electrochemically generated oxide nano ridge structure can be fabricated using probes for atomic force microscopy. Moreover, removing the oxide ridge by hydrofluoric acid etching, nano groove structures can also be obtained. The relationship between the shape of nanostructures and fabrication conditions such as applied voltage, probe scan speed, and radius of curvature of the probe. Finally, nano structures with very small height or depth (several tens-nm wide and sub-nm high or deep) have been fabricated by our method. This is very useful for clarifying nanotribology of micro or nanomechanical devices.

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An off-lattice Monte Carlo simulation using a simplified bead-spring polymer model has been applied to analyzing spreading of ultra-thin lubricants over molecularly smooth solid surfaces. Reptation Model, Rouse Model and the two methods of initializing lubricant films were examined to determine appropriate models for lubricant molecules. It is concluded that Rouse Model and the initialization method that simulates the dip-coating method are essential for the simulation. The results are in good accordance with experimental results. Diffusion coefficients of lubricant films are eventually obtained through the profiles of lubricant films.

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The DNA chip is required of high sensitivity and low cost for practical medical service. We have used polymethylmethacrylate (PMMA) as a substrate of DNA chip for low cost. However, PMMA cannot adhere DNA due to its hydrophobicity. In this work, in order to change the PMMA to be hydrophilic, various ions were irradiated on the surface of PMMA by using an Electron Cyclotron Resonance (ECR) ion shower apparatus. The contact angle of water on the surface of PMMA was reduced by 90%, 84% and 85% by irradiating Ar^+, O_x^+ and N_x^+ ion at best suited condition, respectively.

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The diffusive motion of molecules of monolayer perfluoropolyether lubricants on magnetic disks have been clarified by investigating spreading characteristics. A model for the diffusive motion of the mobile molecule is presented. The diffusive motion can be explained by a modified reptation theory. The mobile molecule makes a snake-like diffusive motion through the bonded ones. These results are useful for building a tribological model of a monolayer lubricant on a magnetic disk.

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We developed a novel slider design that has less flying height sensitivity to altitude and manufacturing tolerances for application to head-disk interfaces of sub 10nm flying height. This design also predicts less off-track vibration in case of slider-disk contacts and it has been confirmed experimentally. We applied "pivot shift" concept to our slider design in order to reduce the flying height loss due to altitude. In this design, the pivot point of the slider is shifted forward toward the leading edge from the usual center position of the slider. This shift increases the pitch moment, which can compensate for flying height loss due to increase in altitude. We also applied "super shallow step" of a few nanometers in depth to our slider design in order to trim the trailing edge rail width of the slider. The trimmed rail can reduce the flying height loss due to manufacturing tolerances and can also reduce the off-track vibration due to slider-disk contacts. By combining the pivot shift concept with the super shallow step design, the flying height of the slider can be reduced to sub 10nm successfully while maintaining needed clearance to ensure the mechanical reliability of the head-disk interface.

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Vibration transfer characteristics through a liquid meniscus bridge were investigated experimentally using the meniscus response apparatus. Effects of the excitation amplitude and the contact angle on the vibration transfer characteristics were clarified. Slip flow model considering slip flow at solid-liquid interface was proposed and the theoretical response was compared with the experimental results. Slip length is derived by the least squares fitting. The large contact angle was obtained by applying oil repellent to a glass plate. It was found that the excitation amplitude affected the vibration transfer characteristics and the contact angle amazingly affected them.

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In this study, we investigated the effect of ultraviolet (UV) irradiation on the thickness stability of molecularly thin lubricant films over magnetic disk surfaces. Step-shaped multilayer (3.5-nm-thick) and monolayer (2-nm-thick) perfluoropolyether AM3001 films were dip-coated on magnetic disk surfaces, respectively, and then exposed to 172-nm UV rays through a photomask. We measured the time-dependent thickness profiles of the lubricant films in the UV-irradiated and non-UV-irradiated regions, respectively. By comparing the profiles, we found that for non-UV-irradiated multilayer films, lubricant thickness decreased with time due to the relaxation process, whereas for UV-irradiated multilayer films, the relaxation process was suppressed because of the increased intermolecular interactions. For monolayer films, the relaxation process was not observed regardless of UV irradiation.

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This paper presents measurements of friction force exerted on molecularly thin lubricant film surfaces using a specially arranged pin-on-disk type friction tester. The measurements were carried out by sliding a 1.5mm diameter glass ball slider on the rotating disk surface with small loading force. PFPE lubricants with and without functional end-groups were dip-coated on magnetic disks covered with diamond-like-carbon (DLC) film. Lubricant film thickness was varied to constitute multiple layered structures of lubricant film on the DLC surface to clarify the stratified effect of thin lubricant film on friction. The tested results indicated that the friction force on the lubricant surface was intimately dependent not only on loading force but also on the layered structure of lubricant film. The effects of the layered structure on friction can be attributed to the interaction between the slider and the lubricant, resulting from the behavior of the end-group functionality.

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Wetting and dewetting phenomena generated on magnetic disks lubricated with PFPE having polar end groups were observed for different lubricant film thicknesses and its mechanism was clarified from the comparison with the spreading characteristics and surface energy variation depending on the film thickness. It is confirmed that the dewetting did not occur for one monolayer thickness, and evidently occurred for double and triple layered thicknesses. In addition, for a thickness thicker than a quadratic layered thickness, the dewetting did not occur for a short time range of a few days while it occurred for a longer time range of a few weeks. These characteristics were found to be well correspondent with the non-replenishment phenomenon arising in a lubricant depletion test, and well explained from the surface energy variation with increasing film thickness.

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In the head-disk interface (HDI) of a hard disk drive (HDD), lubricant deformation has an effect on flying attitude of head slider, as the flying height is decreasing. The time-evolution of lubricant deformation is analyzed using long wave theory. We analyzed various problems by long wave equation. Moreover, we established the analytical method for using both long wave equation and Molecular Gas-film Lubrication (MGL) equation with the gas-liquid lubrication problem. This analysis can be useful for HDI study and other tribological studies that need to investigate the behavior of lubricant on solid.

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This paper describes the interactions between flying head sliders and ultra-thin liquid lubricant films. We investigated the influence of the bonded ratio as well as de-wetting of the lubricant film on the slider dynamics. Zdol2000S was used for the lubricant. The dynamics of sliders was monitored using Laser Doppler Vibrometer (LDV) and Acoustic Emission (AE). The slider hysteresis behavior of touch-down and take-off processes was investigated as a function of the disk velocity. As a result, it is found that the difference between touch-down velocity and take-off velocity of high bonded ratio lubricant films were larger than that of low bonded ratio ones. And the LDV RMS signals for high bonded ratio lubricant films became larger than that for low bonded ratio ones. In addition, it is found that de-wetting of a lubricant film affects the slider dynamics.

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Slider flying instability due to intermolecular force in a head disk interface (HDI) with a 3-5 nm mechanical spacing is a barrier to achieving a 1 Tb/in^2 magnetic recording areal density. A better understanding of the intermolecular force and how to decrease its effect are becoming very important subjects for HDI researchers studying non-contact interfaces. In this paper, a probability model taking account of surface roughness is used to calculate the intermolecular force between disk and slider surfaces with certain roughnesses. A slider with controlled texture/roughness is simulated, and the results indicate that the surface with controlled roughness/texture can greatly reduce the intermolecular force acting on the air bearing surface (ABS).

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In the HDD head process, the control technology of the 3-D shape of the GMR((Giant MagnetoResistance) head is important. This paper presents the numerical analysis of the ion milling process by the 3-D topography simulator. This simulator uses the Level Set Method[1] and the physical model for the moving surface velocity which is based on the experimentally measured etching rate.

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Dynamic characteristics of a magnetic head slider of a hard disk drive were analysed using 2 degrees-of-freedom (2-DOF) mechanical model considering the dynamic pressures due to the van der Waals force and the air bearing force. The corrected van der Waals force equation for multilayers and the molecular gas-film lubrication (MGL) equation were used to calculate the pressures. It was found that the statically stable flying of a slider can no longer be achived at the ultrasmall spacing due to the attractive van der Waals force. It was also found that the response of the slider to the disk surface waviness is degraded even if the staic flying is stable. The animations of the slider motion were shown in order to see the influence of the van der Waals force.

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An optical interferometry is widely used for a flying height measurement of the slider in hard disk drives. In order to obtain an aocurat measurement, both the maximum and the minimum intensity of an optical interference must be strictly calibrated. In this paper we describe the effects of a slider attitude, a spot size and an optical filter bandwidth on the calibration. Generally the calibration is conducted in a unloa process in which the slider is forcibly pulled off from aglass disk. We calculated the slider attitude history in the unload process, then we estimated it's effect considering the spot size and the optical filter bandwidth on the calibration.

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An isolated pad type slider and a narrow trailing edge type slider was designed and fabricated for a partial-contact head-disk interface. Evaluation results showed that friction reduction is the key point for a partial-contact interface. A smaller isolated pad slider exhibited a smaller off-track vibration and less aggressive disk lubricant depletion. Moreover, drive tests of a narrower trailing edge slider showed that narrower trailing edge has the advantage of easier transition from contact to flying.

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Handy relief rollers with a simple pattern are generally used to transcribe its design to a wall just after painting. However, the types of the patterns are limited to several conventional ones, so that interior planners' and decorators' requirements for attractive roller designs are becoming larger. In order to increase the kinds of the roller designs, a new advanced 3D machining system for cylinder models should be established. In this paper, a post-processor, which can generate suitable NC data for multi-axis NC machine tools with a rotary unit, is proposed. The 3D machining system with the post-processor is also presented for attractive interior decorating. The machining system allows us to easily transcribe the relief designs from a flat model surface to a cylinder model surface. The effectiveness of the proposed 3D machining system using the post-processor is demonstrated through actual machining experiments.

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As for the transportation using wheels, it is known that the efficiency is high and, mechanism and control system are simple. Therefore, the transportation using wheel is practical, and widespread. However, the wheel type movement has the difficulty in the rough terrain. In this research, a wheel type mobile robot "Zaurus" with six wheels in which is employed as the link mechanics was developed. In performance evaluation experiments, the climbing over the step twice the height of the diameter of the wheel was achieved. And, the control systems using Neural Network and PID were investigated.

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Up to the present, the robot hands active in various fields as one part of the robots, Industrial robot, humanoid robot, prosthetic hand, medical robot and are demanded tasks that complicated and to be high-degree. But the robot hands have not reached at human the level that can achieve delicate and dexterous tasks. Then, in this study, the robot hand is constructed by imitating human hand in the anatomy, and we aim at achievement of dexterous task similar to human expert and application to prosthetic hand. In this story, we mention a control architecture for an anthropomorphic finger that imitated human index finger in the anatomy.

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After the experimental development of the orthosis with powered joint for the handicapped, this paper deals with the passivity of dynamics in the control of the walking machine. First, the passive dynamic walking machine that walks down the slope is modeled and analyzed from the energy point of view. Then, ankle-driven type of quasi-passive dynamic walking machine is designed and developed by considering the possible application to the orthosis. Experiment of the walking on the horizontal plane is done, and the result is compared with the numerical analysis, that shows the validity of the idea.

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A mechatronics system to support mental image creation was developed. The mechanical part of the system is a 3-DOF manipulator that is composed of a 2-DOF quadrilateral parallel-link actuator and a rotational actuator embedded at arm-end of the parallel-link. A couple of servomotors of the 2-DOF manipulator control the arm-end position. The arm-end actuator controls the direction of a knob attached to the rotational actuator axis. The person is assumed to pinch the knob by his/her fingertips. The knob is rotated to indicate the direction of the on-going stroke, and the position of the knob axis traces the strokes of the presented figures sequentially. A couple of preeminent functions are embedded in the process: one is a preparation effect by "the direction-indicating function," and the other is the reviewal effect by "the traction function." The direction-indicating and traction functions play complementary role

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Since an optical three-axis tactile sensor has good advantages on fracture robustness and surface fitness for applications on robotics, we developed a semispherical three-axis tactile sensor mounted on multi-fingered hand's fingertips. In the present paper, the sensing element that has a columnar feeler and 8 conical feelers is adopted as a sensing element for the present tactile sensor. According to a set of equations formulated in the preceding paper, normal and shearing forces are calculated from integrated gray scale value and centroid displacement caused by conical feeler's contacts, respectively. To evaluate the present tactile sensor, we conducted a series of experiments using an x-z stage, a rotational stage and a force gauge. Although relationship between integrated gray-scale value and normal force had good linearity, its sensitivity depended on latitude of shearing force. However, since the sensitivity of shearing force was uniquely determined by the centroid movement, the relationship between integrated gray-scale value and normal force was easily modified according to the value of shearing force.

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In order to investigate effects on presentation tactile-haptic reality, the authors developed a multi-modal display capable of simulating mechanoreceptors of fingers in addition to the muscle-tendons. The multi-modal display was constituted of a manipulator having three-degrees of freedom and a gripping force display equipped with two tactile displays. The tactile display has a display pad of a 6-by-4 array of stimulus pins, which generates distributed pressure on a human operator's finger surface. In order to evaluate the present display, we performed Experiment A and B. In Experiment A, human operators judged diameters of virtual pegs. The experimental result showed that estimation precision was enhanced by simultaneous presentation of both tactile and force. In Experiment B, human operators performed virtual peg-in-hole tasks. In the case of loose mates of the peg and hole, precision of centering adjustment was enhanced by the simultaneous presentation From these experimental results, we concluded that the present display was effective in virtual reality technology because the operator performs pick and place tasks in handling virtual objects.

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This paper is a study on the development of a sensor for measuring tactile sensation. Human warm feeling on fabrics is compared with the sensor output. At first, warm feeling on each sample is collected through the questionnaire based on the paired comparison semantic differential method. Furthermore, human's motion for the evaluation of the warm feeling is investigated. Next, a sensor using the pyroelectric effect of a PVDF (Polyvinylidene Fluoride) film is fabricated. The surface of the sensor is heated through the temperature control. Then the sensor is moved and contacted with an object through the trajectory control of the contact pressure in order to collect output voltage of the pyroelectric effect. Finally, the measurement using the sensor is carried out on the samples. Comparison with the results shows that the PVDF sensor is available to evaluate the warm feeling.

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This paper describes the methodology of getting the environmental information and path designing for independent moving of mobile robot. The obtained information of obstacles and others by range sensors of mobile robot is treated as the altitude of the potential value. The environmental map is interpolated with the distributed samples' potential value with Kriging. Kriging is one of the spatial data modeling method used mainly in Geostatistics and has impressive ability at spatial interpolation. The path is designed by Potential field method and the method based Traveling Salesman Problem applied Genetic Algorithm. The potency of this proposed method has been verified by simulations.

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In this paper proposes to construct the multi agent system with the game theory, and to control the crowd robot cooperatively. The effectiveness of the proposed method was verified by the pursuit evasion simulation which uses plural robots. In this simulation, pursuit robots are using the differential game to pursue the escape robot. And, pursuit robots are using non-zero-sum two-person game to select the pursuit action and the escape obstruction action. As a result, the pursuit robot acted as a crowd in consideration of the action of other pursuit robots. Moreover, when you compare the usual method with the proposed method, it was clarified that the proposed method was effective.

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The underground radar is used as a nondestructive and non-contact surveying method for imagining complicated underground structures such as stratums and buried objects. However, in order to detect objects from underground radar images with sufficient accuracy, a lot of experience and knowledge of an expert is necessary. Therefore, to make the detection easy, it would be helpful to know how the shape of observation waves received by the underground radar varies with for the shape of underground objects. In this paper, electromagnetic fields for circular underground objects with various diameters are simulated with FDTD method. The shape of the received wave signal is examined with the change of the of underground object diameter by using Fourier analysis.

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We have performed basic experiments for the purpose of applying onomatopoeia to engineering problems. In these experiments, test subjects were made to perform lifting actions while listening to onomatopoeic utterances. We thereby demonstrated that there is a relationship between the onomatopoeic utterances and the lifting forces exerted by the test subjects. We examined how the lifting forces are related to the magnitude of the onomatopoeic utterances and the envelope of these sounds. Furthermore, by comparing this phenomenon with the effects of simple tones and white noise, we investigated how the lifting force is affected depending on whether or not emotion is expressed when uttering the onomatopoeia.

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This paper is concerned with the development of medical and welfare instruments using functional materials. One is the development of an artificial sphincter which is driven by shape memory alloy actuators. The non-contact induction heating system using power transmission coils and the temperature control system are introduced. The other is the development of a sensor whose receptor is a polyvinylidene fluoride (PVDF) film patch. The sensors are available for detecting prostate hardness, monitoring skin conditions. As a welfare instrument, the sensor using PVDF film is introduced for reading Braille. Furthremore, as a home medical care apparatus, the development of a sensor for monitoring sleep conditions is studied.

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Epidural anesthesia is one of the regional anesthesias used for the abdominal surgery and the obstetric analgesia for labor. An anesthesiologist need to place the needle tip at the epidural space precisely. It is important to develop 1) a clinically acceptable reaction force sensing system, 2) a design criteria of the needle tip by a comparative phantom study and a numerical simulation, and 3) an intelligent puncture device with force feedback loop. A phantom study by the author stated in this article.

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Interventional MRI therapy has started in these years, and surgical robots operated under the MRI environment are focused by many researchers to achieve most effective image guided therapy. In this paper, the 2 DOF MRI compatible precision device for interventional navigation is proposed, and system feature is described. It is the purpose that this device supports puncture in the navigation surgery by MRI. It comprises a feed screw, aluminum parts, FRTP parts and ultrasound motor, that are all non-ferromagnetic characteristics. The control device packaging and evaluation experiment with influences of the robot to MR image are reported.

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In this paper, we propose a concept of inner skeleton power assist systems (i.e., power-assisted artificial joints) for human elbow and knee joint and introduce an example of their actuators. The proposed systems can be expected to be artificial joints for the next generation. An electromagnetic actuator is designed as an example of implantable actuators for the inner skeleton power assist systems for the assist of elbow and knee joint motion (i.e., elbow and knee flexion-extension motion in daily activity and rehabilitation for the physically week persons).

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This paper describes a comparison between the three dimensional trajectory of elbow measured by an imega analyzing system (IAS) and that using body-mounted sensor system (3D sensor) proposed by the authors during pitching. The 3D sensor derives 3D trajectory of elbow by the double integration of the 3D body acceleration which is acquired by 3D accelerometer with the sampling frequency 1000[Hz]. Since the derivation of the 3D trajectory is effected by the duration of the double integration, the difference and the correlation coefficient of two trajectories between the IAS and the 3D sensor are calculated by changing the beginning and the end of the integration. Moreover, the condition of acceleration and the angular velocity that minimizes the difference and maximizes the correlation coefficient is investigated. The calculation results show that the size of the angular velocity determines the duration of the double integration to estimate feasible trajectory of the elbow during pitching.

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Main objective of this study is to evaluate physical activity by means of a portable device utilizing accelerometers and a barometer. A simple and effective algorithm was proposed to classify physical activities including vertical movements such as stair climbing, and estimates its exercise intensities. The propose method performed successful classifications and feasible estimation of the energy consumption in the experimental study comparing with the measured values of the expiratory gas monitoring system. The result suggested that the correct evaluation of vertical movements made an improvement in the estimation of energy consumptions, which provides better assessment in physical therapies.

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This paper is a study on the measurement of mechanical properties of a living cardiac myocyte. We propose micro mechanical sensors made of PDMS using soft lithography technique. The device consists of micro columns arrays and work as vertical cantilevers measuring local forces of a myocyte. The generated force derives from the displacement of the top of column. This approach has the potential to measure 2-dimensional mechanical properties of a single myocyte to develop a viscoelastic constitutive equation for a bio-simulator model.

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This paper is a study on the development of a wearable sensor system for reading Braille. The study is intended to develop a compact tactile sensor system which uses a PVDF (Polyvinylidene Fluoride) film for the sensory material. The sensor is mounted onto a fingertip as the wearable system and is moved over Braille manually to obtain the output. Since the unsteady movements yield variations in the waveforms, a robust recognition system is introduced. The developed recognition system consists of three components as follows. First, the signal inputted to the system is divided into individual signal regardless of the variation in the waveforms. Next, those signals are transformed into effective feature vectors in order to suppress the variation. Finally, those vectors are classified and the recognition results are obtained. The classifier is composed of organized dichotomizes made from multi-layer perceptrons to enhance the classification accuracy. To carry out experimental verification, test signals are inputted to the recognition system and the performance of the system is evaluated. The obtained results show that the robust recognition is achieved appropriately.

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This paper reports a study on the development of a new type of artificial rectum valve system using the SMA actuator. At body temperature, the valve presses on the rectum to clog the evacuation. When the SMA actuator is actuated by providing electric energy to it, the valve opens to enable evacuation. To verify the function of the artificial rectum valve as an anal sphincter, preliminary experiments and in vivo animal experiments were conducted. The experiments verify that this valve works well as an artificial rectum valve.

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The authors applied pneumatic actuators to the rehabilitation support of knee and ankle joint motion. Considering the characteristics of the actuator, the authors combined plural actuators as an antagonistic way. First, several layout of the actuators are examined for the knee joint motion and the motion is compared depending on the layout of the actuators. Next, the four actuators are combined for the two DoF motion of the ankle joint, and the motion is compared with and without load. Then, the authors have discussed the availability of the pneumatic actuator to the rehabilitation support, and have confirmed that the actuation is applicable to the coercive joint motion for expanding the joint angle range and the resistive motion for the training of muscles.

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