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

---

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

---

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

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

---

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

---

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)

著者

岡田 正彦

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.13, no.6, pp.356-359, 1975-12-30 (Released:2011-03-09)

参考文献数

7

被引用文献数

1

---

Software techniques for solving two problems in monitoring the electrocardiograms of critically ill patients are described in this Paper.(1) Logical filter for detection of a QRS complex : High frequency components are centered around the peak-points of a QRS complex and the waveform is roughly symmetrical with respect to a vertical line through.the peak-point. These characteristics of the QRS complex are utilized in designing the filter. This filter distinguishes the QRS complex well from other parts of electrocardiograms and various noises.(2) Pattern recognition of a QRS complex with correlation coefficient : One typical QRS complex is selected and designated as “templet”. Subsequent QRS complexes are compared with this “templet” one by one. The degree of similarity to the “templet” is evaluated by a correlation coefficient. Without accurate detection of a QRS duration, 10 points before and after the peak of R-wave respectively (totalling 20 points) are regarded as one QRS complex (sampling rate : 250 points/second). Our method makes it possible to recognize ectopic beats automatically even if noises exist to some extent.

著者

村上 啓二 田中 弘富 増山 善明 吉川 昭

出版者

Japanese Society for Medical and Biological Engineering

雑誌

医用電子と生体工学 (ISSN:00213292)

巻号頁・発行日

vol.20, no.2, pp.113-116, 1982

---

Effects of data compression, to save the processing time in the P-wave recognition program with the adaptive correlating filter (ACF), on the performance of the ACF has been studied.All QRS or QRST regions were eliminated from the record to compress ECG data.<BR>Two indices were adopted as criteria for evaluating the effects. One was derived on the basis of the performance characteristics of the ACF, while the other was the mean error probability in detecting P-waves by using the ACF.<BR>In result, it was shown that the method for data compression could make up for the loss of the P-wave information caused by the data reduction. So the data reduction proposed here makes data compression feasible with little deterioration of the ACF performance.

著者

吉澤 誠 馮 金山 竹田 宏 三浦 誠 山家 智之 片平 美明 仁田 新一

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.26, no.2, pp.83-91, 1988-06-30 (Released:2011-10-14)

参考文献数

10

被引用文献数

8

---

A new hemodynamic measurement system was developed by using the left ventricular assist device (LVAD) to estimate the cardiac function of the natural heart. The LVAD was placed between the left atrium and the aorta for the patient with deeply failed left ventricular pump function and driven by the pneumatic drive unit.In the personal computer system, an on-line identification method was implemented to estimate the coefficients of the autoregressive moving average (ARMA) model whose input and output were corresponding to the drive pressure of the drive unit and the pump flow from LVAD, respectively.Two driving modes of LVAD were compared with each other. One is the co-pulsation mode in which the systolic period of LVAD coincides with that of the natural heart, and the other is the counter-pulsation mode in which the systolic period of LVAD is followed by that of the natural heart.This comparison clarified that the capability of cardiac function of the natural heart could be quantitatively evaluated on the basis of the difference between two frequency responses derived from the coefficients of the ARMA model. This implies that the proposed method is useful for making a decision on weaning from LVAD in the clinical case.

著者

工藤 信樹 清水 孝一 松本 伍良

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.3, pp.194-198, 1985-06-30 (Released:2011-10-14)

参考文献数

12

被引用文献数

3

---

A new method of biotelemetry is proposed, which realizes nonrestrained acquisition of biological signals using the infrared light diffused out from animal skin. This technique is fundamentally different from conventional telemetry techniques which use radio-frequency electromagnetic waves.An optical transmitter which consists of some LED's is implanted beneath the skin. Biological information such as ECG signal is collected in vivo and the light emitted from the LED's is modulated by the signal. The light transmitted through the skin is strongly diffused and spread out in a wide angle. The light is collected by the remotely located optical receivers and the biological information is obtained by demodulating the signal. Thus, the biological information in vivo is obtained without restraining the object with cables or optical fibers.In order to verify the possibility of the above technique, a system, which obtains an ECG from laboratory animals, has been developed. An infrared light was chosen due to its invisibility and high transmittance through the skin. Considering the stability of the communication link and the power consumption of the implanted transmitter, PFM (Pulse Frequency Modulation) technique was used. Using the system, the transcutaneous ECG telemetry was performed successfully.In the experiment, the indirect light reflected and scattered by the walls, the ceiling and the floor was shown to be useful in the optical telemetry. Light transmission patterns through the skin of a mouse were measured. The results suggest the possibility of telemetry even from the deep part of the body cavity.It is concluded that recent progress of optical and electronic technologies have reached the point, where transcutaneous optical telemetry of biological signals has become practically possible.