The mental and physical workload (MPWL) due to motorcycle (MC) and automobile (AM) operation were compared quantitatively by means of ECG R-R intervals (RRI). The RRI of 30 MC riders and 20 AM drivers were measured. Eight statistics were derived from RRI; average (RRM), mean coefficient of variance (mean CV_R-R), auto regressive variability (ARV), power of high-frequency region (HF), central frequency of high-frequency region (HFF), power of low-frequency region (LF), central frequency of low-frequency region (LFF) and ratio of LF and HF (LF/HF). As a result of factor analysis, three common factors which reflect, “stress level” (represented by mean CV_R-R & LF), “parasympathetic tone” (RRM & HF) and “randomness of RRI variability” (ARV) were extracted from these eight statistics. MC riders' stress level gradually increased in accordance with riding distance up to 260-320km, then it started to decrease and parasympathetic tone was enhanced in turn. This phenomenon can be comprehended so as to indicate the difficulty in maintaining attention. On the contrary, AM drivers' stress level increased steadily in accordance with driving distance, but no phenomena thought to affect the maintenance of attention was observed.

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To reduce the time spent on documentation in nursing work, we have developed a Point-of-Care Information System that uses portable terminals. Nursing work consists of not only direct patient care but also indirect nursing work, such as documenting patient information, conferring with other nurses, and preparation of equipment. Though more time spent on direct patient care increases the quality of care provided, the time needed for the indirect work often exceeds the time actually spent on directly caring for patients. Our proposed system was developed to reduce the time spent on documentation in the indirect work and make nursing work more efficient. The system consists of personal digital assistants (PDAs) carried by nurses around the hospital wards, and a nursing server computer located in a nursing station. The system provides three main functions: 1) Data Browsing for reviewing patient information such as brief history, vital-sign charts, and handwritten notes; 2) Schedule Planning for reviewing order list and making To-do lists for the day; and 3) Care Management for executing the orders and recording patient data. With these three functions, the system became one of the first systems that covers the entire loop of daily nursing work. The PDAs and the server computer can share the latest information by data transmission through both wired and wireless devices. Results from hospital evaluations showed that the system can reduce the time needed for nursing documentation by 49%-60%. Also, the system is user-friendly with its pen-based interface and was evaluated positively by more than 80% of the nurses who used it.

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The development of new less-invasive method for cancer therapy is needed to improve the quality of life of cancer patients. For this purpose, appropriate treatment of the exact localized area of cancer is very important. The ultrasonic hyperthermia method has been proposed as a new method for this purpose; however, many difficult problems, such as pain generation due to hot spots produced at the muscle-bone interface, remain to be solved. An alternative method is short-term irradiation of high intensity focused ultrasound (HIFU). This method is effective for treating deep-seated tumors, as a sufficiently high thermal dose can easily be applied to the target area without any severe damage to the normal tissue. However, many problems must still be solved for clinical application. In this paper, the effects of the HIFU method are theoretically and experimentally investigated. The relationship between the thermal dose and thermal denaturalization of tissues is theoretically obtained. The nonlinear behavior of high-intensity ultrasound and the generation of harmonic components are discussed. The relationship between the dose of ultrasonic irradiation and the area of thermal denaturalization are also theoretically discussed, based on the result of computer simulations for various irradiation periods. Distributions of temperature elevation and thermal dose are calculated from the simulations and are visualized using a thermal-sensitive phantom. The results showed that irradiation with short pulses of high intensity ultrasound can produce a sharp gradient of thermal dose at the boundary between cancerous and normal tissues. This means that a sharp boundary of thermal denaturalization can be obtained due to the small influence of heat conduction during a short irradiation period. The effect of changes in SAR and thermal conductivity of tissue on the spreading of the necrosed area is also discussed. The accuracy of computer simulation was validated by comparing the results of thermal phantom experiments and computer simulation.

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Binocular rivalry (BR) is the process where dissimilar images given to corresponding parts of the left and right eyes are perceived alternately at any moment in time. In an attempt to detect the neural activities related to the endogenous alternation of perceived images in BR, we have studied the potentials elicited by the alternation in six healthy subjects. Vertical (or horizontal) and horizontal (or vertical) gratings were presented to the left and right eyes separately. Subjects were instructed to press a button when perceived images were alternated, which triggered data acquisition. As the second experiment (binocular fusion, BF), identical vertical (or horizontal) gratings were presented to both eyes and were changed to horizontal (or vertical) gratings at the intervals of 0.9 to 1.5s. In BF, subjects pressed a button when perceived gratings were changed. As the third experiment (button press, BP), subjects pressed a button intentionally at random moment while identical gratings were presented continuously. EEGs were measured at 20 electrode positions on the scalp by averaging 100 trials in each experiment. A negative component peaking at -55ms was observed in the parietal and central areas in BF. In BR, a broad negative component between -400ms and 0ms was observed in the left parietal, left posterior temporal and left occipital areas. On the other hand, the negative component could not be observed in the BP where gratings were not alternated. These results suggest that the negative component may reflect a neural process related to the alternation of perceived images in both BR and BF. In particular, endogenous alternation in BR may be selectively related to the left parietal, left posterior temporal and left occipital areas.

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Neuromagnetic responses related to the omission of the second sound in triplet of speech sounds were recorded. Three sets of stimuli, which were named as standard, deviant, and omission, consisted of three short Japanese speech sounds. The standard stimuli were consisted of /aoi/, meaning “blue” in Japanese. The deviant stimuli were consisted of /akai/, meaning “red.” The omission stimuli were consisted of /a_i/ (here, /_/ represented the omission of sound). Six male subjects (age range of 23-41) with normal hearing participated in the measurements. Stimuli were presented binaurally, while neuromagnetic responses were recorded over their right and left temporal sides, simultaneously. The responses were separately averaged by standard, deviant and omission. In the omission response, a component related to the omission of the speech sound was observed over the right and/or left hemispheres in 5 of 6 subjects, although its amplitude was very weak. In the subtracted waveforms, i. e., after subtraction of the omission responses from the standard responses, enlarged components were observed in the latency of 258-702msec referenced to the onset of the second sound of the standard stimuli. Equivalent Current Dipoles (ECDs) of the components, which exhibited dipolar field, were estimated in the right hemisphere of two subjects and in the left hemisphere of one subject. The estimated locations of the ECDs seemed to indicate the neural activities in the vicinity of the insula and in the superior temporal sulcus (STS). These results together with other previous studies suggested that STS may subserve a function at sensory level, while the insula may be related to the higher functions such as discrimination of stimuli.

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Phenylboronic acid groups are known to form reversible bonding with vicinal hydroxyl groups in polyol compounds, such as glucose. Using this property of phenylboronic acid, we have prepared phenylboronic acid containing polymer coated quartz resonator for glucose sensing device. We have prepared a copolymer containing both phenylboronic acid and tertiary amine moieties. The copolymer membrane changes its swelling degree with glucose concentration-dependent manner in distilled water. Glucose-responsive swelling changes of a copolymer membrane were then utilized to control glucose-responsive frequency changes with a membrane-coated quartz resonator. Glucose addition to distilled water induces swelling of the cast polymer membrane, leading increased membrane mass and thus increased measurable frequency changes. It is observed that frequency changes are proportional to glucose concentration in the range of 0-450mg/dl. Frequency change rates could be controllable by polymer coating density on quartz resonator. Since the addition of α-methyl-D-glucoside has little influence on the frequency changes, the frequency change by the addition of glucose is indicative of the high selectivity of this system for glucose. Reversible signal output is also demonstrated by stepwise glucose concentration changes. These results support the applicability of the quartz resonator coated with the phenylboronic acid-containing polymer for novel glucose sensing device.

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