出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.30, no.Supplement, pp.157-163, 1992-05-01 (Released:2011-10-14)

著者

南谷 晴之 萩田 紀博

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.18, no.4, pp.256-263, 1980-08-30 (Released:2011-03-09)

参考文献数

31

---

In this study, a neural network model is proposed to obtain -the numerical description of pain mechanisms. The model simulates peripheral receptors, afferent L- and S-fibers and the receptive cells of the spinal cord area Adaptation effect and conduction velocity of each fiber are considered in the model. The activities of peripheral and spinal cord neural cells are represented by the Wilson-Cowan's differential equation, considering the ongoing activity of neurons. Pain and touch sensibilities are estimated by the firing activities of lamina V (Transmission, T) cells and lamina IV cells, respectively.The results of model simulation have been obtained for single square-wave pulse and periodic pulse sequences applied on peripheral receptors. The duration of initial bursts of T and IV cells, which occur soon after the beginning of stimulation, depends on the stimulus intensity and approaches a plateau with increasing intensity. In case the stimulus intensity is increased above the threshold of S-fibers, secondary burst of T cells appears about 50 msec after the stimulation, which is equivalent to the conduction time of S-fibers from the periphery towards the spinal cord cells. High-frequency and high-intensity stimulation gives the typical firing patterns of pain modality, represented by the high secondary burst of T cells which continues during the stimulation. From the results of periodic pulse stimulation, the so-called pain and absolute threshold characteristics have been obtained and have been compared with the results of cutaneous electrical stimulation. Both results are shown by quite a similar relationship between stimulus pulse frequency and stimulus intensity and their characteristics are given by the power function's law of frequency and intensity.The proposed neural network model mimics the pain modality very well, and the results of simulation are in good agreement with some of physiological and experimental results.

著者

山越 憲一 戸川 達男 神谷 瞭 藤井 禎三 土屋 喜一

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.14, no.4, pp.296-302, 1976-08-30 (Released:2011-03-09)

参考文献数

9

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From the point of the optimal theory, the relationship between the branching structure and the mechanical characteristics of a tree was analysed in reference with such parameters as circum-ference, weight, bending moment, branch length and-branching angle, The study was based on a hypothesis that the optimal structure of a tree agrees the minimum energy loss.The total energy loss is the sum of the energy required for the construction which is proportional to the wood' volume of the branches and the energy consumption for supporting the weight of the branches and leaves which is equal to the elastic. strain energy. Results derived theoretically from the hypothesis are as follows : 1) The Maximum bending stress at each branching point is constant.2) The relation between the circurmference (C) at some point and the bending moment (T) acting on the branch is, T∝C3. 3) The relation between the weight (W) of all the parts of the tree peripheral to some branching point and C is, W∝C2.5. 4) The relation between T and W is, W∝T5/6. 5) The relatlon between the branch length (l) and C is, l2 ∝C. 6) When C0, C1, C2 are the circumferences of the mother and daughter branches and θ1, θ2 are their branching angles, the following optimal conditions for a dichotomy are derived;C02.5= C12.5+C22.5 and C13/ sinθ2=C23/ sinθ1.These relations were examined, by measuring the varying size of branches, 76-286 in all, on seven different kinds of trees, and the very good agreements between the theoreiical and actual relations were confirmed.

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.38, no.Supplement, pp.236-240, 2000-05-17 (Released:2011-10-14)

著者

福島 邦彦

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.19, no.5, pp.319-330, 1981-09-30 (Released:2011-07-05)

参考文献数

59

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.34, no.Supplement, pp.396-402, 1996-05-16 (Released:2011-10-14)

著者

酒本 勝之 金子 和真 江崎 光裕 藤井 麻美子 金井 寛 浅野 次義

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.33, no.3, pp.184-191, 1995 (Released:2011-10-14)

参考文献数

14

被引用文献数

2

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A new method (BIM) by bioelectrical impedance for the estimation of human whole body or local part fat volume is described. This method is based upon that the resistivity of adipose tissue is much greater than that of fat-free mass of which frequency characteristics shows β dispersion phenomenon. It is well known that the admittance locus of fat-free mass provides the semicircle. Because the impedance value of trunk is only 10 or 20% of the whole body impedance (Zall) between arm and leg used by the commercialized impedance fat meter, if the fat volume in the trunk increase, the estimation error in the fat volume estimated from Zall would increase. Therefore, instead of Zall, BIM adopts the impedances measured at 5 local parts which are antebrachium, brachium, trunk, femoral part and cruralis. We measured the impedance of each parts for the frequency range from 3kHz to 300kHz and calculate the admittance locus in order to obtain the conductance at much lower frequency (Ge) and much higher frequency (Ginf) than β dispersion frequency. Arms, trunk and legs are represented by parallel models which are cone shape and consists of fat layer and fat-free mass layer. And then we calculate the equivalent conductivity σ of parallel models from Ge or Ginf. From σ, fat volumes of local parts which are arm, trunk and leg and whole body are estimated. When we estimate the fat volume of trunk, in order to take into consideration the adipose tissue which distributes around organs in trunk like liver, stomach, and etc., the weighting function K which is statistically given is multiplied to the equivalent conductivity of trunk. The reference fat volume can be measured by hydrometry. We can conclude that (1) the impedance at the trunk must be measured to consider the fat volume in the trunk, (2) Ge or Ginf must be used instead of impedance at about 50kHz to estimate the fat volume, and (3) correlation coefficients between the whole fat volume measured by hydrometry and that by BIM with Ge and Ginf are about 0.77 and 0.94, respectively.

著者

田中 博 古川 俊之

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.23, no.7, pp.463-470, 1985-12-30 (Released:2011-10-14)

参考文献数

35

被引用文献数

1

著者

竹前 忠 東 好宏 小杉 幸夫

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.38, no.3, pp.246-250, 2000 (Released:2011-10-14)

参考文献数

6

---

We realized a new electrical impedance tomography (EIT) based on the tetrapolar circuit method with the scanning of magnetic field superimposed for localizing the current distribution in biological tissues. In this method, two voltage differences are detected on two sides of the body, in which the distribution of constant current component is parallel. As the voltage difference of one side becomes zero, the eddy current component is produced by a magnetic field applied to the body from an electromagnetic core. Sustaining this state, the electromagnetic core is moved from side to side. The voltage differences at the other side measured during this movement of the magnetic field are used to estimate the resistance distribution of one dimension. As the result of a model experiment, it was confirmed that this method would be useful to realize EIT.

著者

須磨 幸蔵

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.12, no.5, pp.269-276, 1974-10-30 (Released:2011-03-09)

参考文献数

35

---

Einthovenの心電計の発明によって心臓病の診断は大きな進歩をとげた。一方, この十年余ペースメーカーの出現によって房室ブロックをはじめとする不整脈の治療は大きな変革をとげ, エレクトロニクスは心臓病の診断と治療の両面に非常に大きな役割を果たすに至った。1976年東京において第5回国際ペースメーカーシンポジウムが開催されにことになり, わが国においても一般の関心が高まると考えられるが, ここでは房室ブロックおよびペースメーカーについて過去から現在までの概説を試みる。

著者

斉藤 義明 堀 潤一 木竜 徹

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.38, no.2, pp.102-110, 2000 (Released:2011-10-14)

参考文献数

13

被引用文献数

5

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Various vital sensors have been developed for patient monitoring. These sensors restrict patients physically or mentally since either electrodes or probes must be mounted onto a patient's body and then connected to a measuring instrument using a lead wire. In this study, a biomedical-signal detection system capable of being used without subject awareness on the basis of terrestrial magnetism was developed for home use and remote care. When a subject lies on a bed mattress that is situated on a magnetic sheet, the system detects the change in magnetic field related to respiration and heart beat. We have also developed an on-line system that can separate respiration and heart beat components from the detected signal.

著者

野界 武史 平田 恵啓 小林 哲生 栗城 眞也 CSEPE Valeria

出版者

日本エム・イー学会

雑誌

医用電子と生体工学 : 日本ME学会雑誌 = Japanese journal of medical electronics and biological engineering : JJME (ISSN:00213292)

巻号頁・発行日

vol.36, no.2, pp.119-126, 1998-06-10

参考文献数

16

著者

渥美 和彦

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.20, no.7, pp.541-545, 1982-12-30 (Released:2011-03-09)

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.39, no.Supplement2, pp.177-188, 2001-12-01 (Released:2011-10-14)

著者

晴山 典彦 藤井 麻美子 酒本 勝之 金井 寛

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.34, no.3, pp.230-237, 1996 (Released:2011-10-14)

参考文献数

6

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It is very difficult to heat deep seated tumor surrounded by low conductivity tissues, such as bone and fat. We proposed a new RF magnetically induced method for this deep regional hyperthermia. To get high density of induced current in deep tissues, we arranged 4 coils around the sphere agar phantom. The frequency of exciting current is 13.56MHz. In this paper, we will show the calculation method of SAR distribution and temperature distribution in 3D inhomogeneous model. We also discuss the possibility of this heating method from both experiment and calculated results. In the phantom experiment we examined two types of the coils. The calculated results and experimental results show a good agreement, these therefore, the reliability of this calculation method was confirmed. The heating pattern of these coils were not very effective for deep regional hyperthermia. We also calculated temperature distribution in the brain model which was constructed from CT images. We assumed tumor in the brain with half of the blood flow compare to normal tissue. Deep seated tumor was heated by the effect of inhomogeneity and blood flow, except there were hot spots near the coil. In the case of shallow region heating, we can get effective localized heating pattern. From these results, we cannot surely say that this heating method is quite sufficient for deep regional hyperthermia. But since there is no other method to successfully heat the brain non-invasively, this kind of examination with other coil patterns must be continued.

著者

金井 寛

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.20, no.3, pp.140-146, 1982-06-30 (Released:2011-03-09)

参考文献数

41

被引用文献数

1

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.24, no.3, pp.198-206, 1986-06-30 (Released:2011-10-14)

著者

阿部 善右衛門 山田 芳文

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.17, no.7, pp.530-537, 1979-12-30 (Released:2011-03-09)

参考文献数

37

著者

田中 邦雄 清水 哲也 佐野 文男 阿部 善右衛門

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.14, no.1, pp.25-32, 1976-02-29 (Released:2011-03-09)

参考文献数

19

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Since R. Damadian suggested the detectability of tumors by nuclear magnetic resonance (NMR), the authors have focused their attention on the facts such as the quantities related to the kinds of water and tissues. And at least qualitative information could be non-invasively obtained.In this paper, in order to clarify the applicabilities of our proposed magnetic focusing method for non-invasive tumor detection, the nuclear magnetic relaxation time (T1) of transplanted malignant tumor (AH-66) in rat, excised normal and cancerous tissues in man were measured in vitro experiment.The resultant findings are summarized as followings.1) Transplanted malignant tumor in rat showed (30-120) % longer value of T1 than that of the respective normal tissues.2) In 14 cases of the uterus, breast and stomach in man, the T1 of cancerous tissues increased (10-150) % than that of their normal portions.3) When mixed tissue was studied, T1 changed as the ratio of tumor to normal tissue changed.4) The longer the time elapsed, the greater the T1 value exhibited by normal and the smaller the T1 measured for cancerous tissue. When both normal and cancerous tissues coexist, T1 decrement of the tissue is small.

出版者

一般社団法人 日本生体医工学会

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.20, no.Supplement, pp.49-49, 1982-04-15 (Released:2011-10-14)