Electroencephalogram (EEG) can be synchronized with repetitive flicker stimuli with the stimulus frequency above 1 Hz. Such a syncronized EEG, which is referred to be as a steady-state visually evoked potential (SSVEP), is affected by mental concentration on the stimuli under eyes-closed condition. We investigated the amplitude change of the SSVEP in concentrating on flicker stimuli for a novel brain computer interface (BCI) based on the SSVEP with eyes closed for severely disabilities who were not able to control their eye movement to use conventional SSVEP-based BCIs. The grand means of the SSVEP amplitude ratio across 16 subjects were found to be reduced by more than 20 % with reference to the nonconcentration condition over the entire scalp when the subjects concentrated on the flicker stimuli under the conditions of flicker frequency of 10 Hz and stimulus intensity of 5 lx. Such desyncronization was limited to the occipital lobe and left parietal (O1, O2 and P3) under the condition of 14Hz and 5 lx. This result suggests the possibility of SSVEP-based BCI with eyes closed in terms of the mental focus.

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This paper introduces a method to analyze an individual difference in an electroencephalogram (EEG) using a self-organizing map (SOM). The EEG recording position is a left prefrontal pole (Fp1) in the international 10-20 system. The device for recording the EEG uses dry-type sensor and a small number of electrodes. The EEG data is analyzed through the FFT and EEG features are extracted by calculating the time average of the power spectrum of five frequency bands which are theta, low-alpha, high-alpha, low-beta and high-beta, respectively. In order to confirm the individual difference in the EEG, the EEG patterns are classified using the SOM. The EEG patterns are based on human responses on sounds listened to. Finally, we conduct experiments using real EEG data. The experimental results suggest that it is possible to express the individual differences in the EEG using SOM.

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In recent years, the population of elderly people is increasing rapidly. The shortage of workers who take care of them is becoming serious. Based on these situations, the burden of the care workers has become a big social problem. Therefore reducing the care workers burden is important. In this paper, we propose the novel behavior detection system using several ultrasonic radars. In the system, a new decoupling method, in which the transmitting time periods of ultrasonic wave is altered, is introduced into the ultrasonic radars. The effectiveness of the method was confirmed by the field tests with a healthy male in 20 experiments. However, further field tests with elderly persons in actual living facilities are necessary to verify the usefulness of the system for them. This system can be useful for safety management for the elderly people, and reduce the work of a care worker.

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The recent development of double-balloon and capsule endoscopes has enabled the observation of the entire small intestinal area. Consequently, several clinical trials have been carried out. However, it is difficult to use such endoscopes in patients who suffer from intestinal obstruction and adhesion. We have therefore developed an endoscope that can be used in patients who suffer from these problems; it consists of an ileus tube and an optical fiberscope. When this endoscope is removed from the body at a constant speed, the entire small intestine can be observed via control of the balloon internal pressure of the ileus tube. In a previous study, we performed experiments in which an ileus tube that was inserted in a small intestine model made of silicon was pulled out, and confirmed that the control device containing an industrial cylinder could maintain a constant balloon internal pressure to pull out the ileus tube at a constant speed. On the other hand, when a medical syringe was introduced in the control device, the problem of excessive capacity occurred possibly because of the large size of the syringe. In this study, we developed a device for controlling the internal pressure of the balloon using a small medical syringe, and verified its control performance.

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Owing to high DOF, many actuators, in turn, a large size, a heavy weight, and a complicated control mechanism, few shoulder prostheses have been developed. Therefore, adequate mechanical structure and optimization of the structure ’ s configuration to fit for users ’ spatial access and manipulability requirement are necessary. In our previous research, a pneumatic actuator driven parallel mechanism was proposed as shoulder prostheses for daily living use. In this study, new indexes for spatial accessibility were proposed for evaluating the shoulder prostheses. Using the spatial accessibility indexes, the configuration of the parallel link mechanism was optimized. Besides, the effect of biasing spacer and trunk motions on spatial accessibility were considered. The results showed that biasing spacers could improve the spatial accessibility by moving the center of the working space of the prosthesis towards the center of two specified spatial regions, which correspond to the expected frequently accessed area and the reachable area for an individual user ’ s upper limb. And trunk motions could enlarge the working space thus further improve the spatial accessibility. Finally, based on the optimal configuration, the prototype was developed, and we empirically confirmed the behavior of the arm and the effect of the biasing spacers.

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To perform minimally invasive surgeries, state-of-the-art medical technologies are required. This study aims to realize a robot that delivers drugs to the body cavity of a diseased. We have developed a robot that is driven by a magnetic field force and can move in the abdominal cavity. A drug-delivery function that uses magnetic field force to inject and deliver drugs is equipped. We showed that the motion of our drug-delivery function in the cavity was expected by using a solenoid coil to generate a magnetic field. This mechanism injected a small amount of liquid only when a perpendicular magnetic field is applied to the robot. The study results clearly highlighted the need to control the magnetic field and optimize the size and shape of bag with medicinal liquid.

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This paper describes the problems of information acquisition for students with the AVI(Acquired Visual Impairment) in special needs education school. The solutions to facilitate the information acquisition attracted much attention since the types of disabilities had been diversified with an increase of the number of the adult students with the AVI in the high school. The students, having different views for the same information, seem to have difficulties in the information acquisition for activities in school. We conducted the questionnaire survey for the teachers in the high schools above and examined the key issues: (1) supporting solutions by teachers, (2) source of knowledge and information, and (3) inconvenience and problem for students. Teachers devised various methods for teaching students. Students relied on textbooks, teaching materials and teachers as source of knowledge and information. They suffered from the inability to see books, websites and blackboard clearly. We presented the categorical principal components that characterize the relation between information sources and inconvenience of students.

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We developed a prototype of simple virtual reality (VR) system as a support tool to overcome fear of heights. The system consists of one personal computer, one projector and a hemisphere dome screen with the diameter of 1 m. It is a dome-screen type VR system because it makes little burden both to a medical doctor (or a counselor) and to a client. The dome screen is a low-cost type made milky-white plastic. We adopted rear projection using only one projector and could get an image with an effective field of vision. We can use a picture or a movie took from a personal-type digital camera. As for the correction of image distortion, we made the software tool originally. Therefore, the running cost is also low and the operation is easy. As the result of evaluation experiment, we confirmed that the system made a feeling of devotion with little sense of incongruity. It seems to show the possibility that the simple VR system can be utilized as a medical service tool of the spread type.

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We have tried to develop an Integrated Tongue Operation Assistive System; “ I-to-AS ” . The “ I-to-AS” is an assistive control system used to operate powered wheelchairs (PWC), Augmentative and Alternative Communication devices and some other environment control devices, for seriously disabled people. In our preliminary study, the “ I-to-AS ” only had a mouthpiece type remote controller input device. So to add a secondary input device, we developed an intraoral mini-joystick. This has a 3-axes force sensor to detect the direction and magnitude of the operational force. The mini-joystick also has 1-axis force sensor to measure the user ’ s biting pressure. For safety, the system will only work while normal pressure is applied on this sensor, but it won ’ t work while abnormally low or high pressure is applied.
To investigate the maneuverability of the intraoral mini-joystick, five able-bodied candidates drove a PWC by using the intraoral mini-joystick. The driving time of operation by tongue and by normal-joystick were compared. The driving time by tongue was 38.0 ± 6.1[s]. It was about 40% slower than that of the normal-joystick but it was short enough and easy to control. These results suggest the possibility this system would be effective as an assistive tool for severely disabled people.

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