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Akinori Ueno, Yoichi Furusawa, Hiroshi Hoshino, Yoji Ishiyama
2004 Volume 124 Issue 9 Pages
1664-1671
Published: 2004
Released on J-STAGE: December 01, 2004
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This article reports on a novel technique for detecting electrocardiogram (ECG) at a condition where thin cloth is interpolated between sensing electrodes and the skin to which the electrodes are attached. The technique is based upon capacitive coupling composed of the electrode, the cloth and the skin, so that the electrode can lead alternating electrocardiographic current through capacitance of the coupling. The technique is also founded on impedance transforming circuit that has extremely high input impedance around 1000GΩ and low output impedance, so as to match high output impedance of the electrode to low input impedance required by subsequent circuitry. A pilot ECG measuring device was manufactured using the technique and experiments showed (1) ECG recordings using the device with silk of 240μm thickness or with cotton of 564μm thickness were quite similar to ECGs recorded from the skin using conventional system, (2) stable ECGs were observed with the silk below 600μm thickness or with the cotton below 1128μm thickness, (3) effects of long-term measurement and perspiration on ECG waveform were negligible. These results prove feasibility of the proposed technique for detecting ECG by electrodes with fabrics.
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Yuichi Ogawa, Kodo Kawase, Maya Mizuno, Masatsugu Yamashita, Chiko Ota ...
2004 Volume 124 Issue 9 Pages
1672-1677
Published: 2004
Released on J-STAGE: December 01, 2004
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We constructed a THz transillumination system for water content monitoring, and we succeeded in measuring the moisture level in plants. Our measurement system uses a widely tunable coherent THz parametric oscillator source. As target we chose for this experiment a leaf of
Japanese basil. The time variation of the water content in the leaf was monitored in two situations: a leaf freshly cut which is left to dry out, and the leaf of a water stressed plant. We found by real-time measurements that the water content of a cut leaf does not decrease uniformly in time. Also, the response to water stress is delayed by about 5-10 minutes. Furthermore, we demonstrated a moisture measurement using a transillumination THz imaging system. As target we chose for this experiment a leaf of
Hedera helix held between two thin plastic sheets. The change of the moisture distribution is clearly visible. These results show that the method described here can be applied to nondestructive and real-time monitoring of water content in plants.
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Masayoshi Tsubai, Toshihiro Nishimura
2004 Volume 124 Issue 9 Pages
1678-1684
Published: 2004
Released on J-STAGE: December 01, 2004
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We discuss a new morphological operations using double structuring elements (DSEs) and apply them to edge sharpening of the ultrasound images with speckle. The DSEs, a couple of two different structuring elements, varying with the local characteristics of the processing image, yield an edge-sharpening effect, which general single structuring element does not have. Our method sharpens the boundary without speckle emphasis, overshoot nor undershoot because it is based on geometrical characteristics of the image components.
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Masaki Kawakatsu, Hidenori Ishibashi, Masaharu Adachi, Yoshinori Uchik ...
2004 Volume 124 Issue 9 Pages
1685-1691
Published: 2004
Released on J-STAGE: December 01, 2004
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In the biomagnetic measurement, the biomagnetic signal is extremely weak compared with environmental magnetic noise. Therefore, it is important to reduce the noise component. There are many noise-reduction studies for MEG using Independent Component Analysis (ICA). The ICA method is expectable to extract and remove noise components from the brain magnetic field measurement data. However, in these researches, each obtained independent components are artificially distinguished to the noise and the signal. We propose a method of distinguishing to the noise and the signal automatically by using the signal subspace method for vector brain magnetic field. By applying this method to a phantom data and Auditory Evoked Field data, it is shown improvement of the signal to noise ratio and estimated accuracy.
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Tadanori Fukami, Takamasa Shimada, Takao Akatsuka, Yoichi Saito
2004 Volume 124 Issue 9 Pages
1692-1697
Published: 2004
Released on J-STAGE: December 01, 2004
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In audiometry, ABR (Auditory Brainstem Response) is widely used. However, it shows low accuracy in low frequency band. Meanwhile, AMFR (Amplitude-Modulation-Following Response), the response during hearing an amplitude-modulated tone, has high frequency specificity and is brought to attention. As the first step to clinical application of AMFR, we investigated the activated areas in a brain when the subjects hear SAM tone (Sinusoidally Amplitude-Modulated tone) with both ears. We measured following two signals. One is the difference of BOLD (Blood Oxygenation Level Dependent) signal between hearing SAM tone vs. silence, the other is the difference of BOLD signal between hearing SAM tone vs. unmodulated tone. As a result, in the case of SAM vs. silence, the bilaterally auditory cortex (Broadmann Area 41, 42), the biratelally BA 10, left superior frontal gyrus and right superior temporal gyrus were activated (p<0.0037, uncorrected).
In the case of SAM vs. unmodulated tone, the bilaterally superior frontal gyrus (BA 6) and precuneus (BA 7), neighboring area including the bilaterally inferior parietal lobule (BA 40), the bilaterally medial frontal gyrus and superior frontal gyrus were activated (p<0.021, uncorrected). Activations of visual perception due to eye-opened state were detected in some parts of activations.
As a result, we inferred that modulated tone was recognized in the medial frontal gyrus and inferior parietal lobule was the part related to perception of amplitude-modulation.
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Yoshiharu Koya, Mitsuyo Ito, Isao Mizoshiri
2004 Volume 124 Issue 9 Pages
1698-1703
Published: 2004
Released on J-STAGE: December 01, 2004
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Modeling and analysis of the circulation system enables the characteristic decision of circulation system in the body to be made. So, many models of circulation system have been proposed. But, they are complicated because the models include a lot of elements. Therefore, we proposed a complete circulation model as a lumped electrical circuit, which is comparatively simple.
In this paper, we examine the effectiveness of the complete circulation model as a lumped electrical circuit. We use normal, angina pectoris, dilated cardiomyopathy and myocardial infarction for evaluation of the ventricular contraction function.
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Iwao Okutani, Tatsuo Takase
2004 Volume 124 Issue 9 Pages
1704-1711
Published: 2004
Released on J-STAGE: December 01, 2004
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Interactions between regional landscape and sound are investigated in terms of subjects’ brain wave properties, i.e., α wave power spectrum and frequency fluctuation index of brain wave. The landscape samples consist of sea, buildings, crowds, trees, flowers, streamlet, vehicular traffic flow and residential area while the sound samples are made up of crowds sound, insect chirpings, rustling sound of leaves, wave sound, stream murmurings, bird chirpings and supersonic. It is revealed that (1) most of the best combinations of landscape and sound include natural landscape and sound whereas the worst combinations are associated with artificial environments, (2) best(worst) combinations determined via fluctuation index are composed of the landscape and sound which are evaluated as bests(worsts) at landscape only or sound only stimulus tests, (3) based on theα wave power spectrum, some of the best combinations include the landscapes and sounds which are evaluated low at the single stimulus tests and also some worst combinations include the stream murmuring sound or wave sound which are highly ranked at the sound only tests, (4) since supersonic appears in many worst combinations, it is likely to bring about unpleasant effects on human psychology.
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Takehito Hayami, Osamu Watanabe, Osamu Hiwaki
2004 Volume 124 Issue 9 Pages
1712-1718
Published: 2004
Released on J-STAGE: December 01, 2004
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It is a useful method to estimate the position and the current distribution of peripheral nerves with magnetic field measurement as a non-invasive inspection. A simulation study was executed to estimate the electric current sources in a nerve fiber by the magnetic fields with L1-norm method. L1-norm method using magnetic fields usually estimated scattered dipoles over the space. In case of measurement of magnetic field around a limb, approximate direction of nerve fibers is known. Therefore this study proposed a method to estimate the current dipoles in a nerve fiber in an arm or leg by selecting the direction of current dipoles resulted from L1-norm method.
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Yuichiro Hashimoto, Masashi Kawasumi, Masao Saito
2004 Volume 124 Issue 9 Pages
1719-1724
Published: 2004
Released on J-STAGE: December 01, 2004
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The effect of magnetic field on cell has long been investigated, but there are few quantitative investigations of the migration of cells. Cell-migration is important as one of the fundamental activities of the cell. This study proposes a method to evaluate quantitatively the cell-diffusion constant and the effect of static magnetic field on cell migration. The cell-lines are neuroblastoma (NG108-15), fibroblastoma (NIH/3T3) and osteoblastoma (MC3T3-E1). The static magnetic field of 30 mT or 120 mT is impressed by a permanent magnet in vertical or horizontal direction to the dish. It is shown that the cell-diffusion constant can represent the cell migration as the cell activity. It is found that the cell migration is enhanced by exposure to the magnetic field, depending on the kind of cell. It is conjectured that the effect of static magnetic field affects the cell migration, which is at the downstream of the information transmission.
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Hideyuki Momoki, Hidenobu Arimoto, Naoto Kakuta, Yukio Yamada
2004 Volume 124 Issue 9 Pages
1725-1730
Published: 2004
Released on J-STAGE: December 01, 2004
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We have proposed a new method of measuring temperature of media containing water by near infrared spectroscopy and multivariate analysis. The peak wavelength of the water absorption band at about 1450 nm shifts with the change in temperature. By measuring the wavelength shift of the absorption band we can measure the temperature of media containing water whenever it is transparent like water solutions or turbid like biological tissues. Fundamental experiments have validated the proposed method. The measurement accuracy has been found to be less than 0.1 °C for pure water, 0.3 °C for turbid media with transmission measurement, and 0.6 °C for turbid media with reflection measurement.
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Motoshi Tanaka, Takayuki Miyashita, Hiroshi Inoue, Yoshitsugu Niiyama
2004 Volume 124 Issue 9 Pages
1731-1737
Published: 2004
Released on J-STAGE: December 01, 2004
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As a fundamental study on the objective evaluation of TV picture degradation by electromagnetic noise with visual physiological information, the electroencephalogram (EEG) activity was measured when a still TV picture was degraded by the burst noise whose rms and duration were changed. A degradation was subjectively evaluated by three-grade impairment scale of “Not Annoying”, “Slightly Annoying”, and “Annoying”. Measured EEGs were analyzed by an averaging technique. In the results, the amplitude of the event related potential P300 becomes larger when the subjects feel the noise “Annoying”.
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Saeko Samejima, Masakazu Kobayashi
2004 Volume 124 Issue 9 Pages
1738-1743
Published: 2004
Released on J-STAGE: December 01, 2004
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Autofluorescence (AF) measurement of human bronchus tissues are practically used for the detection of early stage lung cancers. Problems associated with the interference between the excitation light and the AF signal and the lack of the precise analysis of the AF characteristics limit the capability of the technique. In this study, we used a ultra-violet laser diode (UV-LD) and a ultra-violet light emitting diode (UV-LED) as the alternative light source for the AF measurement. An AF analysis system that can analyze the spectroscopic data of about 5mm×5mm with a spatial resolution of about 10 micro meters were established. The AF spectrum was measured for 512×512 pixels and the intensity mapping as a function of a certain emission wavelength was obtained. The numerical calculation of the data (including differential imaging and the chromaticity diagram projection) was performed and the precise feature of the AF was revealed.
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Hirooki Aoki, Hidetoshi Nakamura, Masato Nakajima
2004 Volume 124 Issue 9 Pages
1744-1752
Published: 2004
Released on J-STAGE: December 01, 2004
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Every conventional respiration monitoring technique requires at least one sensor to be attached to the body of the subject during measurement, thereby imposing a sense of restraint that results in aversion against measurements that would last over consecutive days. To solve this problem, we developed a respiration monitoring system for sleepers, and it uses a fiber-grating vision sensor, which is a type of active image sensor to achieve non-contact respiration monitoring. In this paper, we verified the effectiveness of the system, and proposed screening method of the sleep disordered breathing. It was shown that our system could equivalently measure the respiration with thermistor and accelerograph. And, the respiratory condition of sleepers can be grasped by our screening method in one look, and it seems to be useful for the support of the screening of sleep disordered breathing.
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Osamu Sakata, Tsuyoshi Shiina, Yoichi Saito
2004 Volume 124 Issue 9 Pages
1753-1758
Published: 2004
Released on J-STAGE: December 01, 2004
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In this paper, multidimensional directed phase analysis is proposed as a means of causality analysis for multiple time series, is proposed. The multidimensional directed phase is a phase with causality, which is associated with multidimensional directed coherence. Using multidimensional directed phase analysis, direction and time of a signal flow among multidimensional time series can be estimated. In two simulations, artificial time series have been analyzed by the new method to confirm its characteristics. In first simulation, accuracy of estimation of signal flow time has been investigated. Second, a complex signal flow pattern has been analyzed. Next, the multidimensional directed phase analysis and the multidimensional directed coherence analysis have been applied to EEG data of normal volunteer. As a result, we have got information differ from common learning which is the difference between the phase of a frontal alpha waves and an occipital is π.
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Keiichi Fujita, Kazuto Tamura, Wataru Kaneko, Hiroaki Ishizawa, Eiji T ...
2004 Volume 124 Issue 9 Pages
1759-1765
Published: 2004
Released on J-STAGE: December 01, 2004
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Recently, diabetics have been steadily increasing, because change of diet, lack of exercise, increase an alcoholic intake, and increase a stress. It is a very serious problem for us. About 23.6 millions of people in Japan approach the danger of diabetes. Therefore, it is necessary to get insulin injection. And they have to measure blood glucose again and again a day. So, they are burden too heavy.
This paper describes a new noninvasive measurement of blood glucose based on optical sensing. This uses Fourier transform infrared spectroscopy of attenuated total reflection. Non-invasive measurement was carried out by using 3 methods. And standard error of prediction is about ±20mg/dl by 3 method. This paper also describes practical application of this method.
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Takashi Seki, Kazuhiko Hamamoto
2004 Volume 124 Issue 9 Pages
1766-1772
Published: 2004
Released on J-STAGE: December 01, 2004
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Recently, medical information system in dental field goes into digital system. In the system, X-ray image can be taken in digital modality and input to the system directly. Consequently, it is easy to combine the image data with alpha-numerical data which are stored in the conventional medical information system. It is useful to manipulate alpha-numerical data and image data simultaneously.
The purpose of this research is to develop a new coding method for dental X-ray image. The method enables to reduce a disk space to store the images and transmit the images through Internet or LAN lightly. I attempt to apply multi-resolution analysis (wavelet transform) to accomplish the purpose. Proposed method achieves low bit-rate compared with conventional method.
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Kazuhiko Hamamoto, Motoyoshi Sato
2004 Volume 124 Issue 9 Pages
1773-1779
Published: 2004
Released on J-STAGE: December 01, 2004
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3D imaging technique is very important and indispensable in diagnosis. The main stream of the technique is one in which 3D image is reconstructed from a set of slice images, such as X-ray CT and MRI. However, these systems require large space and high costs. On the other hand, a low cost and small size 3D imaging system is needed in clinical veterinary medicine, for example, in the case of diagnosis in X-ray car or pasture area. We propose a novel 3D imaging technique using 2-D X-ray radiographic images. This system can be realized by cheaper system than X-ray CT and enables to get 3D image in X-ray car or portable X-ray equipment. In this paper, a 3D visualization technique from 2-D radiographic images is proposed and several reconstructions are shown. These reconstructions are evaluated by veterinarians.
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