This paper shows a numerical analysis of vibration plate type propulsion mechanisms that mimic aquatic organisms which promote under water using waving motion of flexible fins. In recent years, various studies of the aquatic propulsion mechanism using vibration plate which inspired from the aquatic organisms have been advancing. However, the propulsive efficiency of this mechanism is inferior to conventional screw propeller propulsion mechanism. Finding out optimal designs and vibrating conditions of the elastic plate is the one of the solution to improve the propulsion efficiency. And numerical analysis is effective to evaluate various designs and conditions. In this paper, we tried to apply the smoothed particle hydrodynamics, SPH to analyze the aquatic propulsion mechanisms.

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Chemical plume tracing by the autonomous robot is expected in various fields including detection of toxic gas source. In this study, we improved CPT performance of robot by designing sniffing system. The design is based on silkmoth's wing flapping which draw surrounding air to deliver smells to its antennae. To evaluate the system, we carried out odor source localization experiment in three different odor environments of (1)wind tunnel, (2)open space and (3)shifting wind. At the odor source, air containing ethanol is spouted every second. As a result, our sniffing system showed high environmentally robustness performance of which success ratio are higher than 90% in all environments we set.

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We have been investigating how to use microorganisms for bio-micromachines. We succeeded to rotate φ0.5mm micro impeller by motion controlled Paramecium. The Paramecium was controlled by the weak electrical field by applying their negative galvanotaxis. In our previous paper, we succeeded controlling paramecium very stably for over 100 laps along the star-shaped target route in the vertical plane. The overrun on the downward route, however, was larger than that on the upward route in the vertical plane. It was caused by the difference of the swimming speed on each of routes. In this paper, we developed a new motion control algorithm to decrease this overrun. In our former algorithm, the change timing of the target point was decided by the previous change timing and the previous turning point. In the new algorithm, we change this adjusting method to refer the same target point of the past laps using smoothing value calculated by the integral of the equal ratio attenuation. By using this adjustment method, we succeeded to decrease the overrun. We also investigated the transportability of the object by using motion controlled paramecium in the vertical pool. We found that paramecia often cause their avoiding reaction when they hit object made of hard material. In the case of the object made of soft material, paramecia can push more often and more easily. Therefore, we decided to change the target object from hard plastic to soft gel. We succeeded to transport and drop a gel oval sphere to the target place by manually controlled paramecium in the vertical plane pool.

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We have been investigating how to use protists as living micromachines by controlling their behaviors using their taxes. Because of the difficulty of attaching tools on protist such as Paramecium, we are now investigating the applicability of the water flea for bio-micromachine. Water fleas are small crustacean and they wear outer shells as external skeletons. Therefore, we can attach operational tools on the shell by chemical adhesion. In our former studies, we succeeded to control Daphnia magna's motion by illuminating the blue LED light to guide the swimming direction using their strong positive phototaxis. In our previous report, an operation tool was attached on a Daphnia magna, and we examined whether the operational tool enhance their ability of the object transportation or not in comparison with the previously examined transportation ability of Daphnia without tools. If we use rectangle OPS film for operational tool, it was possible to transport an object by the tool attached Daphnia. It has, however, taken longer time than the case without tools. Therefore, in this study, we change the operational tool to the polypropylene needle. We decided to install bent 2 needles on the back of the Daphnia. This tool can greatly shorten the transportation time. The maneuverability of Daphnia in this setting, however, was worse especially during pushing object. The other issue to solve for improving the Daphnia's controllability is that if the Daphnia is near the sidewall of the control pool, the LED light is difficult to irradiate. To solve this problem, we newly developed the LED rotatable type motion control pool. The Daphnia's controllability around the sidewall was improved by this new pool.

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We have been developing motor-tendon-joint series connection type biomimetic soft actuators to make robots act jumping, running and dancing like animals. We developed an artificial silicone rubber tendon structure for the robot to mimic animal's muscular-skeletal structure. In this paper, we optimized a previously installed digital filter and succeeded in stabilization of an actuator both standing still and slow moving by using different attenuation coefficient. Second, we have remodeled an actuator to give high durability and have reduced the weight of it. After manufacturing that, we made a bending and stretching reaction jumping and consecutive jumping according to the jumping height. We use the tendon structure effectively and that a light-weight and high output actuator is considered in the future.

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In this paper, we investigated how to drive a waterwheel by position controlled downward flow of the Euglena's bioconvection. The position of the downward flow was controlled by applying Euglena's phototaxis to the scanning blue laser beam. Formally, we succeeded to drive a seesaw by electrically position controlled downward flow of the Tetrahymena's bioconvection. In this paper, we aimed to reproduce the laser control version of this seesaw driving by using Euglena. We have already confirmed that if the experiment is done in the horizontal planar pool, we could make any shapes of Euglena group and we could also assemble simple mechanical parts by pushing the part by Euglena group. In the case of the vertical planar pool, however, it is difficult to produce strong downward flow by irradiating laser from side direction. In this study, therefore, we first investigated the basic conditions to control the bioconvection downward flow by irradiating the scanning blue laser from the top surface. The results, although it succeeded in the drive of 180° rotation, showed that to generate and to control a steady bioconvection downward flow was very difficult due to the Euglena's poor swimming performance. We reduced the friction of the waterwheel and introduce the top surface irradiation to guide the Euglena located at around the pool side into the bioconvection flow. By using this scheme, we are able to make rotate the waterwheel over 180deg. We also tried to drive 20mm span seesaw that we could not reciprocate it by the downward flow generated by the laser irradiation from side direction. The result showed that the seesaw could drive over 13 reciprocation by using the downward flow generated by the laser irradiation from the top surface.

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We have been investigating how to use microorganisms for bio-micromachines. We succeeded to control the motion of the protists, using their galvano-taxis and phototaxis. In this study, we investigated how to control Bacillus subtilis using their chemotaxis. The difficult point to make a motion control system using chemotaxis is that once we sprayed the chemical substances for control, how to erase this effect in the next control. We thought the neutralization is suitable if we use acid/alkaline as a spraying substances. First, we investigated the basic reaction of Bacillus subtilis to the acid and the alkaline solution. Generally, Bacillus subtilis is thought to prefer neutral (pH7) circumstance. Our results, however, showed that Bacillus gathered to the acid. Next, we made a chemical substance spraying system by modifying the inkjet printer. By using this system, we can make/disappear the character by the bacteria group.

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Pneumatic actuators have a low stiffness and low cost, which enables disposability of system components. They are highly useful for medical use in terms of infection prevention and easiness to compatible with biological systems. We designed a pneumatic soft actuator, called "fiber-reinforced cylindrical rubber actuator (henceforth FCRA)", and manufactured an extension type 3-degrees-of-freedom bending model by combining the three FCRAs. We derived the theoretical formula used to describe and evaluate static properties of our model, and then validated it through various actuation experiments for extension and bending movements. As a result, our theory has successfully explained all the experimental results. We are currently planning to apply the proposed model to the tip part of colonoscopes.

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Bipedal robots have been developed that are capable of various motions such as walking, running and jumping. In particular, dynamic motion including running and jumping requires high power in a short time. Humans have an elastic element and a viscous element in the muscles. So humans generate the instantaneous force by the elastic element when they kick ground and damp impact force by the viscous element when they make a landing. Therefore we develop a leg robot for jumping that relies on these elements. This robot uses a straight-fiber-type artificial muscle and a magnetorheological (MR) brake. In this study, we produced one-leg robot with 2-DOF, structured the 2-DOF jumping model considering landing and calculated the jumping height by the simulation. As a simulation result the robot jumped safety. The jumping height was 50 mm in this simulation.

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It is important to explore and observe under the seabed in terms of biological and geological researches. In particular, sampling of the saline mud including seabed mineral resources and marine sediments plays a large part of the explorations. Therefore, we propose an excavation robot with peristaltic crawling for the explorations beneath deep-sea floor. This robot consists of three units; a propulsion unit, an excavation unit and an extraction unit. Oil hydraulic artificial muscle is strong candidate for a deep-sea propulsion actuator but we have not experienced of the deep-sea hydraulically-operated muscle development. We thus develop an excavation robot using pneumatic artificial muscle in the first stage of development of the proposed robot. We also have characteristic experiments, running experiments and an excavating experiments. As a result, we confirmed that an artificial muscle could be used as excavation robot's propulsion actuator.

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The robot is trying to increase the output for a performance-enhancing, in the case of rigid actuator such as a motor or hydraulic actuator, there is a tendency that the weight is also increased. On the other hand, organisms such as human beings, have gained a high output by a short time to accumulate and release the elastic energy in the muscle (instantaneous force). Also controls the use output and overall movement the nature of a variable viscoelastic with the muscle. Therefore, in this study, we developed a manipulator with a 2-DOF variable viscoelastic joint using a straight-fiber-type artificial muscle and magnetorheological (MR) brake. Then, we take up throwing operation as an example of motion utilizing the instantaneous force and intend to control the subsequent movement from the occurrence of the instantaneous force. In this paper, it confirmed utility of a simple model of 2-DOF variable viscoelastic manipulator constructed and the viscosity control of the apparent by MR brakes.

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Currently, in order to prevent road accidents depression caused by aging of sewer pipes, the inspection of the pipe is required. In particular, pressure pipes in existing equipment becomes complex pipeline is difficult inspection. So we have developed a peristaltic crawling robot that reproduces the earthworm locomotion. This robot is composed of seven units, six joints, and the head part with an attached camera. In this study, we developed a new joint to reduce buckling which causes a reduction in traveling speed, and aimed to improve the running speed of the robot. Then, to perform the running test into the horizontal, vertical and two types of bent pipe having different radius of curvature and confirmed the effectiveness of the joint.

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Medical technologies are rapidly been developed in late years. However the effective treatment for colon cancer has not yet been established. A colonoscope with few burdens on a patient is expected from both doctors and patients. We pay out attention to a pneumatic soft actuator and are going to apply it to colonoscopes because it is safe and flexible. We designed a new actuator, called "Fiber reinforced Cylindrical Rubber Actuator (henceforth, FCRA)" and manufactured a 3 DOF bending model by combining the three FCRAs. The FCRA is cheap, can be easily manufactured. In addition, it is safe because it is driven by air pressure. We conducted various experiments in which extension of FCRA and curve angles of the proposed model were measured to evaluate whether they have enough movement performance as colonoscopes.

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This paper discusses a detection method of steady state visual evoked potential (SSVEP) in short time for the sake of future use in brain machine interface (BMI). Preliminary experiments were carried out to determine the form and color of a blinking symbol and the number of the electrodes to be used. As results, the blinking symbol was chosen as white square, and the background color was chosen as black. In addition, three electrodes were chosen to be used. Using the short time Fourier transform (STFT) and the moving-average method, the analysis method of electroencephalogram (EEG) for detecting SSVEP and detection conditions of SSVEP were determined. Then, experiments for detecting SSVEP were executed using the blinking animation, in which the white square symbol blinks in 8Hz, 10Hz, 12Hz, and 15Hz respectively, as visual stimulus. As for the blinking stimulus in 8Hz and 10Hz, the detection rate of 75% was obtained in 6 seconds, and as for the blinking stimulus in 12Hz and 15Hz, the detection rate of 100% was obtained in 6 seconds.

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Organism use monoarticular muscles and biarticular muscles when driving the joints. Compliance with monoarticular muscles and biarticular muscles are doing the control of limb tip compliance of the biological. Previous studies have confirmed this characteristic by adding a mechanism corresponding to biarticular muscles to the robot arm. Generally, the direction of the trajectory match against any direction of the external force of the arm tip at the compliance characteristics of the arm circularity. In this paper, 2-link arm which has two motors showed approach to meet this characteristic. Also, we control the size of the tip compliance that varies with position. As a result, we have confirmed by simulation to satisfy this characteristic when tip displacement amount is small.

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TKA (Total Knee Arthroplasty) is an effective treatment for the people who suffer from severe knee disease. Many motion simulators have been developed to evaluate the performance of an artificial knee joint. However, it is difficult to realize a real human lower-limb condition by the motion simulator, especially for the deep knee flexion of the lower-limb. We have developed a lower-limb motion simulator which is close to human lower-limb mechanism. The developed simulator is driven by wires instead of muscles of human lower-limb and the deep knee flexion can be realized like real human lower-limb. In this paper, to achieve the human-like flexion/extension motion of the knee joint and hip joint, impedance control method has been applied.

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We propose the way to incorporate synchronization-based control to a robotic wear for standing up motion assist. And we use a non-exoskeleton robotic wear to confirm the effect of synchronization-based control for standing up motion. We have investigated the effect of the mutual torque and EMG with changing speed of the robotic wear. It was found that the muscle activation of the gluteus rectus femoris is mostly decreased during standing up under certain condition and the robotic wear synchronized human standing up motion.

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This paper proposes the robot remote operation using a force constraints based on the data transmission signal level. A mobile robot is controlled by a haptic device through wireless LAN. First, the three stages signal level is set reaction force to return increases as the signal level is low. Secondly, we evaluate a range of signal level in the experimental environment. Lastly, the robot is operated without the reaction force and using the reaction force. The experiment proves the validity of robot remote operation using a force constraint based on the signal level.

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In robotics applications where a system is manipulated by a user, such as by teleoperation, conventional approaches often require the user to have visual information about the state of the robots. However, there are numerous applications in which visual information is difficult or impossible to obtain. Therefore, we developed a feedback display utilizing voice-coil-type tactors in order to facilitate manipulation of a robotic system without the aid of conventional information displays of the robot's state such as video or sensor values. In our previous work, we have presented the development of our prototype and its evaluation in simulation environment. This paper describes the results of our experiments using a two-link robot arm proportional to an average human's arm and the evaluation of the state recognition via the vibration of our device.

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In Japan, when the Great East Japan Earthquake occurred, a lot of robots were mainly used in order to cope with Fukushima nuclear accident and investigate disaster areas, and since then the development of rescue robots has been focused on further. We have paid attention to the mechanism of peristaltic crawling, and the rescue robot having this mechanism is more suitable for movement in narrow space or on irregular ground than others. In this research, we suppose that the peristaltic crawling robot which we have developed moves in a narrow pipe, and we propose a pattern for the fastest forward movement there and estimate its validity by using the simulation of Q-learning and Genetic Algorithm.

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This study focused on gait analysis of patients with spinocerebellar degeneration (SCD) for the purpose of clinical application of robotic wear to SCD patients. The aim of this study was to investigate the physiological mechanisms underlining unsteady gait of SCD. We evaluated quantitatively and compared gait parameters in four SCD patients and two healthy control individuals (NC). The evaluations included lower joint angle (hip, knee, ankle), Center of Gravity (COG) and time factor (stance phase time, gait cycle time, double supporting phase, rate of double supporting phase). As a result, joint angle of knee and ankle showed significant differences between SCD and NC (^<**>p<0.01). COG and time factor except rate of double supporting phase showed significant differences (^*p<0.05). These data will be of value to see how gait assist to SCD patients can be achieved by robotic wear.

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In this paper, we focus on peristaltic movements of the earthworm, and aim to develop the peristaltic mobile robot. To analyze turning motions of the robot, a dynamic equation in two-dimensional plane is derived and numerical simulations are demonstrated.

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In this study, we made a three-dimension model of human body when they did the soccer instep kick and analyzed the motion characters between senior soccer player and junior soccer player. This dynamic model of kick movement consists of 9 segments and 13 degrees of freedom of joint motions. The result showed that when they kick the ball, the energy of the body and waist transport to the thigh and then transport to the shank and as the speed of the foot increase rapidly before the impact, the energy of the waist increases to kill the influence of the foot in order to keep balance.

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A body receives a lot of information of an environment and sends it to a brain. Thereafter, the body receives a signal corresponding to the movement and takes an action to the environment. It takes for granted that we focus on the body structure. We developed Bio-inspired Quadruped Robot. The robot has same size of a real cheetah and same Biologial-Plausible muscle moment arms. Its legs are driven by pneumatic artificial muscles. An experiment of a walk shows us a possibility that a biologic muscle-skeletal has a potentially stable walk function.

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In order to develop a bio-actuator, we propose to align the orientations of C2C12 cells using a collagen fiber. In this paper, we describe the experimental results of the culture of C2C12 cell using the collagen fiber. The results show the effectiveness of the collagen fiber to control the orientation of the C2C12 cells.

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In this paper we evaluated effects of a lower limb type robotic wear on walking assistance for patients with hemiparesis. The control method of the robotic wear was synchronization based control to make the cooperating motion with the wearer. The experimental results showed that the robotic wear was effective to make wide steps and fast walking.

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A novel method for improving the haptic sensitivity for bilateral control system is proposed. The goal of this work is to enhance the force transmission in a bilateral system, so that even a small force acting on the slave side can be felt from the master side. There are two steps in the proposed method. The first step is frequency recognition where the force frequency of the specified contact interface is recognized using frequency spectrum. After that, an amplifier is developed for the boosting up the force signal for that particular frequency during the transmission. Experiments are done using a linear-motor based bilateral system, and according to the results, the sensitivity is significantly improved with the proposed method.

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In recent years, the studies on haptic interfaces have progressed. Currently, we have developed "Haptic Desk," which can detect information of force and information of contact position by a simple mechanism with force sensors. However, there is a problem that calculation accuracy of a contact position is low when force exerted on the desk is small. So, this paper proposes usage of information of differentiated force to calculate a correct contact point. If differential value of force is large when force is small, calculation accuracy of a contact position becomes high by using information of differentiated force instead of information of force. The experiment results showed validity of the proposed method.

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Touch panels are spreading as a good candidate of intuitive man-machine interfaces. On the other hand, various consumer electronics with various functions are spreading, too. This paper deals with a tactile interface for versatile and intuitive input. "Haptic Desk" is a desk-type tactile interface that force sensors are attached to the legs of the desk. However, if the desk is vibrated, the error of the calculated external force and contact point occurs. Because the inertial force of the desk is not considered, the error occurs. For reduction of the error, this paper expands the method of Haptic Desk by using an acceleration sensor. The usefulness of the proposed method is shown by experiments.

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This research studies a haptic interface with a virtual coupling (VC) including a fractional derivative. As a VC, a virtual stiffness and viscosity are generally used but the maximum stiffness is restricted by the sampling rate. To address this issue, this research considers to using a VC consisting of a FIR approximation of a fractional derivative and analyzes the passivity of a fractional derivative term. Then, this paper considers to a VC using a linear combination with several FIR approximations of a fractional derivative and proposes a method to design coefficients using a steepest descent method for a linear combination, and performs experiments to show the effectiveness.

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In this paper, we report the texture quantitative measurement using the miniature multi-axial tactile sensor with microcantilevers which are fabricated by MEMS technology and embedded in the elastomer. The Si microcantilevers are deformed by both normal and shear forces and the deflection of the cantilever can be detected as resistance change of a strain gauge. The resistance changes by active-touching (pushing and sliding) to the object have been characterized and they are correlated with hardness, thickness, and roughness of the object. The first component obtained by principal component analysis of the correlation matrix among the resistance changes shows the surface texture characteristics (roughness, smoothness, friction) of the object. On the other hand, the second principal component shows texture characteristics including both bulky and elastic feelings of the object.

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Haptics is important as well as visual presentation to provide high quality virtual experience. Conventional haptic devices have large overhanging drive mechanisms from the outline of the hand, it is possible to spoil the quality of visual information. This paper describes a glove type haptic device designed compactly by using a small drive mechanism using the SMA.

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At present, no practical training for maxillofacial palpation has been conducted in the dental education curriculum. Against this educational background, the coauthor dentists requested us to develop a virtual training system that enables dental students to undergo maxillofacial palpation against a patient. Then, this paper presents a virtual training system for maxillofacial palpation by using virtual reality and haptic interface. In the present stage, we used multi-CT image of PHANToM to construct a virtual patient model. The dynamic model of the patient model is improved by using free mesh method, which can perform efficient computation.

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This report describes development of a mobile robot's armor which is enable to detect pushing or touching with any objects on its surface. In order to achieve the purpose, it is necessary to design suitable layout of strain gauges as haptic sensors on the armor when changing surface of the armor such as widely bends or distortion with pushing. The armor should be shapely, and it is to be desired that number of haptic sensors is reduced. Therefore, it is required to detect efficiently changing on the surface by haptic sensors in even small number. In this report, it is shown that the layout by 34 sets of strain gauges as haptic sensors is designed based on analysis of stress on surface of the armor.

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Recently, the study for master-slave surgical robots, which has bilateral force feedback control, is attracting a lot of attention. At the same moment, you need haptic interfaces which are effective for controlling these surgical robots safely and precisely. In our laboratory, we have developed some admittance-based haptic interfaces because these interfaces have some characteristics which are effective for robotic surgery. However, when those devices move, they generate a little vibration because those devices are designed with unduration wave gearing systems. This vibration makes ill effect for controlling surgical robots precisely. In this research, we design a new admittance-based haptic interface and taking away such vibrations.

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This paper describes a haptic device, aimed at presenting the sense that a forefinger traces an object and made up of nonmagnetic metal and a permanent magnet. We make the experimental model which is composed of a high speed camera and motorized linear stages and which changes the produced force by controlling the velocity of motorized linear stages which are mounted magnets. In addition, we measure the generated force with a load cell in order to verify that an experimental model can generate force in accordance with theory.

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Motions of our body are generated by muscle contractions. Effort to move our body can be estimated by knowing the muscle activity to generate the motion. In this study, we propose a real-time muscular effort visualization system for an upper extremity with a low calculation cost. We picked up representative configurations of the arm, and the muscle activations to maintain the postures were estimated by the OpenSim in advance. The muscle activations at the arm configurations that were not picked up were obtained by a linear interpolation calculation using the estimated muscle activation values of the neighboring representative configurations. The obtained muscle activations were stored in a database, and the visualization system showed the muscular effort of the current arm configuration by searching the database.

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The identification method using time-scale transformation has been proposed for inertial parameters in passive motion. This method can realize more precise identification compared with the conventional method. However, it is not clear from the previous reports how much the precision is affected by measurement noise. Compared with the conventional method, this paper demonstrates the influence of the identification precision by the measurement noise through simulations.

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This paper presents basic characteristic of thin McKibben artificial muscle, such as contractile force, shrinkage factor, and durability and development of upper limb muscle mechanism. McKibben artificial muscle is soft and light actuator which shrinks by air pressure. McKibben artificial muscle has compliance and its movement is like real muscle. Thin McKibben artificial muscles are possible to bund and shrinkage of the artificial muscle is increased by bundling the artificial muscle. Human musculoskeletal structure has a mechanism which is different from conventional robot, such as the mechanism that center of rotation changes, and multi-joint muscle mechanism. By using a thin McKibben artificial muscle, I reproduce the movement of the human upper limb.

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By developing a redundant musculoskeletal robot using thin McKibben artificial muscles based on human anatomy, we aim to realize the same motion and characteristics as a human. A thin McKibben artificial muscle has compliance and flexibility. To use this for a musculoskeletal robot, we have developed multifilament pneumatic muscle that is a bundle of thin McKibben artificial muscles and has characteristics similar to those of human muscle. On the other hand, the actuators of conventional musculoskeletal robots are very heavy, are not densely attached, and have weak backdrivability. Because multifilament pneumatic muscles are light and can be densely attached, we can overcome these problems by attaching them to the musculoskeletal robot as skeletal muscle and can additionally realize a redundant system equivalent to the human drive mechanism. In this paper, we report a method for fabricating multifilament pneumatic muscles imitating various muscles and the development of an ankle of our robot.

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This research aims to estimate effect of assist device in real work field. First, Human motion is measured by 6-axis motion tracking devise that combines a 3-axis accelerometer and a 3-axis gyroscope placed on shank, thigh and back. Next, lumbar joint torque and assisting effect of Smart Suit Lite in the motion are estimated by interactive musculoskeletal simulation. Conventional method to estimate joint torque is using full body motion data measured by optical motion capturing system. But in this research, joint torque can be estimated by only 3 angles of links which is body, thigh and lower leg. Usability of proposal method is verified by the field experiment. As the result of the experiment, workload was evaluated and assistive effect of Smart Suit Lite was estimated by measured motion.

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Electrical muscle stimulation (EMS) has been utilized in various haptic interface. In this study, we focused on the haptic display method that induces a haptic sensation by activating muscle contraction during electrical stimulation. We incorporated a pseudo-haptic display by using electrical stimulation and developed an interaction system with virtual characters. The stimulus intensity and stimulated muscles were determined according to the contact position between virtual characters and the distance that virtual characters pushed into the each other.

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Swallowing, or deglutition, is simple and smooth process to transport food and drink from the mouth to the stomach, whereas it is difficult to understand its physiological mechanism because it consists of complex neuromuscular coordination. Movements of the hyoid are important to describe deglutition in pharyngeal phase. We therefore develop a musculoskeletal model of the hyoid based on anatomical knowledge to verify activities of muscles around the hyoid during deglutition. Individual muscle force is estimated by the inverse dynamics computation and optimization. The estimation results of muscle force are compared to the results found in a previous study. The results of this study contributes to provide greater insight into deglutition and to improve treatments for dysphagia.

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In this paper, we propose a method of human-to-human skin contact area measurement. Human-to-human skin contact is a primitive communication way to express intimacy, encouragement, etc. Additionally, skin contact is used for therapy of autism, mood disorder, etc. Its quantitative measurement and visualization would contribute for related researches in scientific, medical and physiological fields. Our proposed system utilizes bio-acoustic signals which propagate through bodies. When one wears a vibration device and another wears a vibration sensor device, the sensor captures bio-acoustic waves whose magnitude depends on how large area they touch. We describe design and fabrication of the devices. Then we report about our fundamental experiment and its positive results.

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A tactile device which utilizes a 3 degree of freedom small parallel mechanism is developed. The device presents pressure sensation, two directional share force and vibration at a user's fingertip. The device is designed to be used together with a glove type device. The whole system including the tactile device and the glove type device is expected to present various sensation to the user's hand.

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In a research field on rendering of thermal sensation, Peltier device that can both heat and cool is often employed. Then recently, as the means to enhance the bandwidth of the thermal rendering, novel structure that utilizes temperature gradient prepared on metallic plate has been proposed. However, the performance of thermal control using the system is discussed little so far. In this study, analyses on tracking performance of temperature control are conducted using describing function. By using the describing function, it becomes possible to derive the frequency characteristics of saturation element included in the control system. Based on the analyses, relation between the tracking performance and the maximum/minimum temperatures at the ends of plate is discussed. The analyses are checked by numerical results.

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The aim of this study is to analyze the operating force of the index finger during pressing a switch on the Electric Surgical Unit (ESU). The study about the kinematic and static characteristics of the index finger, which operates the ESU, has not been reported. The position of a switch on the ESU has been designed without evaluating the characteristics of the index finger driven model. The index finger posture which was measured by a three-dimensional motion analysis system and the tendon-muscle driven system of index finger were used to simulate the fingertip forces. The measured value of the fingertip force was recorded simultaneously using the force sensor. By comparing both results, extrinsic muscle has been the most effect of pressing a switch on the ESU.

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This paper proposes a set-point control method for a musculoskeletal system considering maximum muscular force. In our previous work, the set-point control method for a musculoskeletal system was proposed which combines a feedforward control with a sensory feedback control including a considerable time-delay. However, the maximum output force of each muscle have not been considered though it sometimes induces a wind-up phenomenon because of the saturation of the muscular force. The ratio function to determine the ratio of feedforward and feedback control inputs is newly introduced in this paper to prevent such a wind-up phenomenon without the saturation of muscular force, and generate more sophisticated reaction motion even if disturbances are added on the end-point during movement. Numerical simulation results are shown to demonstrate the effectiveness of the proposed method.

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Despite being a common foot deformity, the biomechanics of flatfoot has not been fully understood and optimal surgery towards individual patients still pose difficulties to medical doctors. Computer model is one option to solve this problem. In this paper, a finite element (FE) model of a flatfoot was presented based on CT measurements. Balance standing simulations were performed and results were compared with experimental data to validate the model. One example of surgical simulation (osteotomy) was conduced to show the performance of the model.

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This study is aimed to developed of wearable sensor system, and propose an estimation method of lumbosacral alignment and lumbar load caused by changes in posture. Obtains the lumbosacral size from the X-ray image, the lumbosacral size calibration method is developed using the body surface area and height. Using these method, and confirm lumbosacral alignment estimation accuracy and the lumbar load estimation accuracy.

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