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Volume 14, Issue 2
Displaying 1-13 of 13 articles from this issue
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Ken-ichi IKEDA, Makoto NOSHIRO1976 Volume 14 Issue 2 Pages 95-103
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
JOURNAL FREE ACCESSThe medical system is one of social systems with dynamic characteristic in which many subsystems are complicatedly interrelated. All aspects of its behavior should be analyzed with emphasis placed on the interrelationships between its iubsystems. Systems dynamics developed by Forrester is proposed as a suitable method for the analysis of the medical system. In systems dynamics social systems are expressed in the same form of differential equations as physical systems. They are solved numerically by digital computers. Systems dynamics is concerned with feedback systems, and at taches more imporetance upon correctly representing the structure of the system, than on accurately reproducing observed real system behavior. It is the primary objective of systems dynamics to understand the system behavior on the whole using a mathematical model. Assumptions based on mental models are needed for the model's formulation when complete empirical data are not available. A model is finally a modeler's view. It is constructed to collect and arrange his thoughts and to remove inconsistencies in them. Sensitivity analysis must be made to search for the model parame-ters requiring accuracy. The application of systems dynamics to the medical system is illustrated by a model of the foundation of automated multiphasic health testing systems.View full abstractDownload PDF (1610K) -
Michitoshi INOUE, Noritake HOKI, Hiroshi INADA, Hiroshi ABE, Toshiyuki ...1976 Volume 14 Issue 2 Pages 104-110
Published: April 30, 1976
Released on J-STAGE: August 16, 2011
JOURNAL FREE ACCESSA simulation study is made to analyse the coronary arterial blood flow pattern in terms of the intramural hemodynamic parameters. In the present study, the variable resistances of the intramural portion of coronary vessels are estimated from the extravascular pressure and the intravascular pressure, based on the elastic diagram of each blood vessel. The phasic coronary flow andthe hemodynamic parameters were obtained by the analog digital simulator from the time-serial values of the aortic pressure, left ventricular pressure, right atrial pressure, and left ventricular volume. The obtained flow pattern in the extramural coronary artery was in excellent similarity with that measured with an electromagnetic flow meter. The coronary venous flow showed twoforward flows, the larger one appearing in the systolic phase and the smaller one in the diastolic phase. The extramural coronary arterial flow in systolic phase was strongly suggested to be primarily by the “throttling mechanism”, and partially also by the “massage mechanism” of the intramural extravascular pressure. The good agreement of these results with the experimentally demonstrated findings indicates that the coronary circulation model in this study is reasonable andcompatible with further simulation to evaluate the other factors.View full abstractDownload PDF (1129K) -
Hideo OOI, Yoshiharu MIKI1976 Volume 14 Issue 2 Pages 111-117
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
JOURNAL FREE ACCESSThe diagnostic accuracy of the breast cancer thermograms may. depend on the vascularity of the breast, the size, location, depth and histological type of the tumor, and the temperature resolution of the infra-red camera, in addition to the visual and subjective readings of the thermograms.
To reduce the visual and subjective errors of the thermogram readings, frontal view thermograms of the chest in 49 female patients with breast tumor were subjected to computer - analysis. Video signals from an infra-red camera (JTG-MA Thermoviewer) were on-line digitized at 255 levels with respect to 8700 points per thermogram and simultaneously converted to °C. Mean and highest temperature differences between the bilateral breasts, and the temperature difference between the tumor and the symmetrical point within the contra-lateral breast, when the tumor corresponded with the highest point of the temperature, were used as features in differentiation of hot or cold tumors.
The overall accuracy of the computer analysis was similar to that of the visual reading of the thermogram; 62% of malignant tumors were evaluated as hot tumors and 87% of benign tumors as cold tumors. The visual and computer readings were identical for 83-85% of all tumors.*Received on Jun. 16th 1975, Revised on Dec. 17th 1975View full abstractDownload PDF (1246K) -
Shoogo UENO, Shigeaki MATSUOKA1976 Volume 14 Issue 2 Pages 118-124
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
JOURNAL FREE ACCESSA computer display system of the EEG is presented in order to clarify the relation between the localization of brain lesions and abnormal EEG activities in patients with central nervous system diseases. The system is based upon two parts. One is derivation of an equivalent potential defined as a square root of average power over a desirable frequency band in the power spectrum of 40 sec EEG data. The other is computation for mapping. Interpolation is carried out by means of the two-variable sampling function so as to satisfy potentials at 5 x 5 grid points. The interpolated values are quantized to 11 levels, and finally, potential distributions over the surface of the head are printed out on line-printers of each frequency band separately as shown on topographic maps. The EEG map displays some kinds of EEG abnormalities, for example, diffuseness of delta activity, asymmetry of alpha fields and suppression pattern of sleep spindles in patients with brain tumor or cerebrovascular diseases.View full abstractDownload PDF (1210K) -
Hideto IDE, Sukiro OBATA1976 Volume 14 Issue 2 Pages 125-128
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
JOURNAL FREE ACCESSThis paper deals with vibrotactile stimuli that are suitable as reading aid for the blind. The functional properties of vibratory sense of skin were studied for a blind aid by means of psycho-physical experiments with respect to the two-point threshold. In order to observe vibrotactile stimulus by using both the electrical and mechanical stimuli, the subjects were provided with Ag-AgCl electrodes at two points on their finger.
The two-point threshold by using both the electrical and mechanical stimuli changed to a smaller value by 0.5 mm at 200 Hz compared to that stimulated only by the mechanical stimulus.
Furthermore in the experiment the two-point threshold of each finger was measured by using both the electrical and mechanical stimuli.View full abstractDownload PDF (639K) -
Yoshitake YAMAMOTO, Tatsuma YAMAMOTO1976 Volume 14 Issue 2 Pages 129-132
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
JOURNAL FREE ACCESSThis paper explains the construction of equivalent circuit with fixed elements for skin impedance which satisfy the Cole-Cole circular arc law.
The Cole-Cole dispersion system having continuously distributed relaxation times can be simulated by the system of some discrete relaxation times, and approximate equation is assumed as follows :
P (ω) =Z (ω) -Z∞/Z0-Z∞=1/1+ (jωτm) β≅n∑i=1Ri/jωCiRi/n∑i=1Ri
where Z (ω) is skin impedance and the suffixes 0 and co refer to zero and infinite angular frequency.βandτmare parameters of the Cole-Cole arc. To determine the optimum coefficients Ri Ci of thisequation some conditions and evaluation function are provided. Ri, Ci< are frequency-independent fixed elements. Then, optimum coefficients were obtained for β=0.5-0.9 for the cases n=3, 5, 7. The equivalent circuit, constructed by n series arrangements of parallel resistance Ri and capacitance Ci combination and series resistance Z∞, simulates in good agreement skin impedance over the wide frequency range. It is useful to the simulator of skin impedance in the case, for example, of signal distortion caused by skin impedance appearing : in, electrocardiography.View full abstractDownload PDF (576K) -
[in Japanese]1976 Volume 14 Issue 2 Pages 133-140
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
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[in Japanese]1976 Volume 14 Issue 2 Pages 141-152
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
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[in Japanese]1976 Volume 14 Issue 2 Pages 153-155
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
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[in Japanese], [in Japanese]1976 Volume 14 Issue 2 Pages 156-158
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
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[in Japanese]1976 Volume 14 Issue 2 Pages 159-160
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
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[in Japanese]1976 Volume 14 Issue 2 Pages 161-162
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
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1976 Volume 14 Issue 2 Pages 166-167
Published: April 30, 1976
Released on J-STAGE: March 09, 2011
JOURNAL FREE ACCESSDownload PDF (284K)
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