Japanese journal of medical electronics and biological engineering
Online ISSN : 2185-5498
Print ISSN : 0021-3292
ISSN-L : 0021-3292
Volume 5, Issue 5
Displaying 1-11 of 11 articles from this issue
  • [in Japanese]
    1967 Volume 5 Issue 5 Pages 335
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
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  • Masamitsu OSHIMA, Tatsuo TOGAWA
    1967 Volume 5 Issue 5 Pages 336-344
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    Recent progress in the field of magnetism in biology and medicine is reviewed in this article. There are two important subjects in this field. One is the use of magnetism in the observation of biological phenomena, such as electromagnetic blood flowmeter, external observation of blood flow emf in strong magnetic field, magnetic resonance and detection of a small magnetic field of the heart. Another subject is the biological effects of static magnetic fields. Many interesting results have been reported by J. M. Barnothy and other authors, though some negative results also exist. In the theoretical interpretation of the effects of magnetic fields, there still remain many difficulties.
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  • Kazuo IKEGAYA, Nobuo SUZUMURA, Keiichi MATSUHISA
    1967 Volume 5 Issue 5 Pages 345-351
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    Detailed information on the mechanical impedance of human chest wall is mandatory in estimating the heart sound and designing the phonocardiographic microphone. In order to meet the purpose of obtaining the infomation, an electrostatic transducer has been constructed on a phonocardiographic microphone of contact type as a mechanical impedance-measuring device (vibrometer) which is driven electrodynamically and picks up the signals electrostatically. With the aid of this device, the mechanical impedance of human chest wall has been measured under various contact forces. According to this method the contact force is controlled very easily and accurately during measurement.
    The experimental results indicate that the magnitude of the mechanical impedance of human chest wall, having its minimum value at 100 to 200 cps, increases along with the contact force below the frequency giving the minimum inpedance but is not sensitive to the change of the force above this frequency.
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  • Motonao TANAKA, Yoshimitsu KIKUCHI
    1967 Volume 5 Issue 5 Pages 352-363
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    The use of a concave transducer in the ultrasono-cardiotomography has many favourable effects on the improvement of the picture quality of the tomograms. In this paper, these favourable effects of the concave transducer on the ultrasono-tomogram are discussed on the basis of the results of theoretical analysis and experimental sound field measurement.
    Actual calculations of the sound field for the concave transducers are performed by using Torigai's theory which in for near and far sound fields generated by a concave transducer.
    The theoretical results are compared with the experimental patterns of the sound field which are obtained by measuring the echo intensity from a small target placed in a water medium, and are found to coincide well with the experimental results. By employing a concept designated as “distance-functional directivity”, the azimuthal resolving power of the transducer is examined, and it is found that the concave transducer has favourable effects on the improvement of the azimuthal resolving power because of its narrow beam width due to the converging effect.
    From the consideration on the sound field pattern, when the concave transducer is used for the ultrasonic reflection technique, it is concluded that better results should follow by the use of a transducer having such a configuration as (radius of the transducer) 2/ (radius of curvature × wave length in the medium) _??_4. By employing the transducer of this configuration, the length of the Fresnel's interference zone is made shorter that of a plane circular piston of the same diameter, and the beam width is made sufficiently narrow.
    These facts markedly appeared in the picture quality of the actual tomogram of an excised dog heart taken by an immersed method. It is considered that the use of concave transducers makes the miniaturization of actual transducers and the introduction of STC (sensitivity-time-control) circuit easier.
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  • Hiroyoshi MORI, Tokuro NAGAYAMA, Kenryu OSHITA, Takashi IDE, Keizo NAK ...
    1967 Volume 5 Issue 5 Pages 364-375
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    A new type of analog computer, specially designed for the analysis of spatial vectorcardiograms, were introduced. This “spatial magnitude, velocity and acceleration electrocardiograph” can compute the following calculations automatically, using VCG leads as input :
    Spatial magnitude ECG=√X2+Y2+Z2
    Spatial velocity ECG=_??_
    Spatial acceleration ECG=_??_Electrical characteristics of the differential, the squaring, the extracting and the rectifying circuits were excellent.
    Spatial magnitude, velocity or acceleration ECG under normal and various pathologic conditions showed the corresponding characteristic patterns. Spatial magnitude ECG was considered as the expression of spatial magnitude of the cardiac vectors on linear time scale. Spatial velocity ECG expressed the rate of change of arc length of spatial vector loop. Acceleration ECG was considered to express the rate of change of the velocity of inscription of spatial vector loop. The velocity or acceleration ECG could not be considered to express the velocity or acceleration of the impulse transmission within the heart directly, although considered to be closely related with them. “coronary T waves” are regarded as the expression of the abnormality of velocity of T loop.
    Delayed velocity or acceleration of initial QRS vector was frequently observed in cases of myocardial infarction, and leads to correct diagnosis in cases in which standard ECG were equivocal. In more than 50% of cases of myocardial infarction where the T waves of standard ECG returned to normal, abnormalities of T waves of spatial velocity ECG were observed.
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  • Kenji HIWATASHI, Shojiro NAGATA
    1967 Volume 5 Issue 5 Pages 376-383
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    This paper is concerned with a simple model of the vertebrate visual system, the model being constructed by electronic circuits. The neural networks in the visual system are considered as multilayer spatio-temporal circuits.
    A neuron unit was simulated by electronic circuits-4 transistors and 5 diodes-and, then, a simple model simulating the vertebrate visual system was constructed by them.This model consists of a receptor cell layer (photo-diodes layer) and 4 neuronal layers and can detect edges, moving objects, and corners of stimulated patterns automatically.
    Such a model seems to be useful for neurophysiological studies of the visual system in living organisms.
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  • [in Japanese], [in Japanese]
    1967 Volume 5 Issue 5 Pages 384-390
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese]
    1967 Volume 5 Issue 5 Pages 391-392
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
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  • 1967 Volume 5 Issue 5 Pages 393-400
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
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  • 1967 Volume 5 Issue 5 Pages 401-402
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    Download PDF (350K)
  • 1967 Volume 5 Issue 5 Pages 404-412
    Published: November 25, 1967
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    Download PDF (1490K)
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