著者

岩瀬 英仁 姫野 龍太郎 加藤 陽子

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.44, no.3, pp.428-434, 2006 (Released:2008-05-01)

参考文献数

12

被引用文献数

1

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The numerical simulation system of hemodynamics has been developed for the purpose of advanced medicine. The simulation system we have developed realizes a highly efficient simulation process by adopting the voxel model of blood vessels obtained by medical images and a newly developed scheme based on VOF-FVM corresponding to voxel models. The new simulation system does not require mesh generation because of the use of rectangular coordinates. The voxel model of a blood vessel can be constructed very quickly using the voxel model builder we developed. Furthermore, we developed an input system for boundary conditions, which makes it possible for the user to input boundary conditions easily and quickly through a user-friendly interface. To certify the numerical results rapidly, software for animating the blood flow has been developed. We examined the preciseness of the hemodynamics simulation system in the case of a linear tube and a U-shaped tube. The results were in agreement with experimental results and theoretical solutions. As an example of hemodynamics simulation, we examined the blood flow of an internal carotid artery. The simulation system attained high performance compared with the result obtained using the authors' previous method. It especially improves the efficiency of modeling and mesh generation.

著者

田中 茂雄 野川 雅道 山越 憲一

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.44, no.4, pp.582-587, 2006 (Released:2008-05-29)

参考文献数

8

被引用文献数

3

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The purpose of this study is to investigate the optical absorbance spectrum of bone tissue in the near-infrared region for the development of bone densitometry using near-infrared light. Using bone samples from a bovine femur, optical absorbance spectrums were measured between 750∼2500 nm. With high bone density, the absorbance increased beyond 1400 nm. To predict bone density from the spectrum data, pairs of wavelengths with absorbance ratios or differences having a high correlation coefficient (r>0.99) with bone density were identified. One of the best results was shown by a pair of 1200 nm and 1550 nm with coefficients(r) of 0.994 and 0.996 for absorbance ratio and difference, respectively. Even in thedensity range of the trabecular bone, the coefficients were 0.892 and 0.881 for absorbance ratio and difference, respectively. The results suggest the possibility applying near-infrared spectroscopy to bone densitometry.

著者

竹下 悠哉 角屋 智香 木村 勁介 松永 理恵 栗城 眞也 横澤 宏一

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.53, no.2, pp.84-89, 2015-04-10 (Released:2015-06-25)

参考文献数

12

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We examined whether auditory steady-state response (ASSR), which is known as a lower-order brain response, can be modulated by expectations accompanying the progression of a musical phrase. We fabricated musical melodies consisted of seven tones, the amplitudes of which were modulated at 40Hz, under two conditions:the final (7th) tone was either congruent or incongruent with respect to the musical context of the melodies. Two control experiments were also conducted. The objective of one control experiment was to investigate the effect of the preceding sound (6th) on the final tone (7th) by presenting two final tones (6th and 7th) extracted from the melodies, and the objective of the other control experiment was to investigate the effect of hearing a pitch itself by presenting a tone sequence of ascending and descending scales between A♭5 and C7. The ASSR source strengths were estimated by magnetoencephalography. The strength of the 7th tone of the melodies was significantly larger in the incongruent condition than in the congruent condition. This difference could not be explained by effects of the preceding sound and pitch of the target tone, suggesting that ASSR was modulated by musical expectancy.

出版者

Japanese Society for Medical and Biological Engineering

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.46, no.1, pp.224-226, 2008

著者

水島 洋

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.44, no.3, pp.416-421, 2006 (Released:2008-05-01)

参考文献数

2

著者

笹木 悠一郎 鈴木 拓志 岩上 卓磨 谷 卓治 長沼 秀樹 木野 久志 HYTTINEN JARI KELLOMAKI MINNA 田中 徹

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.52, no.Supplement, pp.O-253-O-254, 2014 (Released:2014-10-04)

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In this study, we have developed a chip-surface stimulus electrode array for fully-implantable subretinal prosthesis chip. To realize visual restoration with high resolution, stimulus electrodes should be miniaturized and arrayed with high density. When we miniaturize them, however, their electrochemical impedances become higher and their amount of charge injection become smaller. Additionally, as the number of electrodes increases, it becomes difficult to make electrical connection to each pixel of the retinal prosthesis chip and each electrode by electrical wiring. To overcome these problems, we have developed the stimulus electrodes that have low electrochemical impedances and large charge injection capacities, and established a fabrication process of chip-surface stimulus electrode array. We fabricated the stimulus electrodes made of extremely porous platinum which had large-surface-area compared with conventional Pt. We also fabricated the chip-surface stimulus electrodes array on the subretinal prosthesis chip which surface was rough and covered with insulator film.

著者

本谷 崇之 森 正人

出版者

Japanese Society for Medical and Biological Engineering

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.52, pp.O-287-O-288, 2014

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With recent advanced and complex medical technologies, viewing the locations of blood vessels and organs through 3D-reconstructed images during medical operations is essential for safe and accurate procedures. The conventional observation methods require the use of computer mice with the hand, which is inappropriate in sanitary environments such as operation rooms. We developed an application program for monitoring volume-rendered images using the Leap Motion, a remote-controlling device instead of conventional mice. In this research, we realized an interface that allows the users to have synchronized perception and understanding of holding 3D objects, which can be frustrating when using the Leap Motion, through the postures of fingers and timing input. In our demonstrational experiment, doctors reviewed that they could observe three-dimensional location information in a sanitary manner through easy operations. This method proves the possibility of the Leap Motion becoming an indispensable device in diverse medical fields.

著者

福田 浩士 小田垣 雅人 樋脇 治

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.46, no.6, pp.684-689, 2008-12-10 (Released:2009-05-22)

参考文献数

8

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Using high-density electroencephalography (EEG) , the brain regions involved in tapping of the index fingers were investigated. Subjects were requested to perform voluntary alternate tapping movements with both index fingers as fast as possible. During the task, the tapping mode in which both index fingers moved simultaneously was interlaced. The alternate tapping (A-mode) and simultaneous tapping (S-mode) groups were extracted using a histogram of the inter-tapping intervals. EEG coherence was used to evaluate functional connectivity between cortical regions. Compared with the S-mode, connectivity increased significantly in the A-mode in the mesial-central circuitry including the supplementary motor area (SMA) and the primary motor area (M1) , in the fronto-centroparietal circuitry including the primary somatosensory area (S1) and the premotor area (PM) , and in the fronto-central circuitry including the PM and M1 in the dominant hemisphere. In addition, interhemispheric connectivity increased in the PMs of both hemispheres. These findings indicate that the connectivity involved in the internal onset of the movement (SMA-M1) , in the sensori-motor integration (S1-PM, PM-M1) and in the phase planning (both PMs) is associated with the involuntary switching between A-mode and S-mode.

著者

古場 隼人 中田 金一 秋山 謙次 折目 由紀彦 高森 達也 山海 嘉之

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.49, no.1, pp.84-90, 2011-02-10 (Released:2011-12-13)

参考文献数

18

被引用文献数

1

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Ischemia is a main cause for many cardiovascular diseases, and can be caused by increases in the vascular resistance at the artery (Ra), as a result of a decreased artery diameter. Although Ra is useful for cardiovascular diagnoses, its evaluation was difficult in the past because Ra cannot be measured directly. The purpose of this study is to construct and verify a method for the quantitative evaluation of Ra for the future application of cardiovascular diagnosis. Ra cannot be measured directly; therefore, we developed a method for identifying Ra using the Aortic blood-pressure (AoP) and the blood-flow volume (Flow), which are measurable. In this method, we use a mathematical model that represents the characteristics of the vascular dynamics. Here, Ra is a parameter in the model, and is identified using the least square method applied to the measured AoP and Flow volume. Thus, Ra can be evaluated quantitatively as a reflection of the actual vascular resistance at the artery. Through animal experiments on seven pigs, we verified that Ra reflects the actual vascular resistance at the artery. First, the femoral arteries were exposed in order to install a flow-meter probe and a catheter for AoP measurement. Next, the femoral artery near the flow-meter probe was intentionally stenosed. As a result, the identified value of Ra significantly increased (P<0.05) by a factor of 3.58 (from 0.233±0.151 to 0.836±0.654 [mmHg min/ml] ). This result indicates that the identified resistance, Ra, reflected the vascular resistance at the artery. In conclusion, we showed it is possible to realize an evaluation method for vascular resistance at artery that can improve cardiovascular diagnoses.

著者

吉澤 誠 杉田 典大 阿部 誠 本間 経康 大内 仁 布川 憲司 山家 智之

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.52, no.Supplement, pp.SY-15-SY-16, 2014 (Released:2014-10-04)

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Super aging society such as Japan would need tele-healthcare systems for home medical care to suppress medical cost inflation. In this situation, we have developed a tele-healthcare system for end-of life decision at home using a wireless electrocardiograph combined with a smartphone and a sphygmogram signal extracted from an ordinary video camera. The experimental results have indicated that long term monitoring through the smartphone and a server will provide rich information on the patient's terminal status for doctors in remote locations. However, it is necessary to collect many clinical data to predict the timing of end-of-life more precisely.

著者

岩田 彰

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.49, no.2, pp.363-365, 2011-04-10 (Released:2011-12-14)

参考文献数

6

著者

大平 雅子 須栗 一路 野村 収作

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.49, no.6, pp.798-804, 2011-12-10 (Released:2012-04-10)

参考文献数

32

被引用文献数

1

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(OBJECTIVE) The change in the secretion of stress-related bio-chemical substances, which are cortisol, immunoglobulin A (sIgA), and alpha-amylase, while asleep was regarded. As for the sample collection, we developed and proposed a saliva collection technique as a non-invasive and non-disturbing manner of sample collection while asleep, whereas the blood collection should impose greater psycho-physiological stresses to subjects. (METHOD) Subjects, 10 male university students, were instructed to take a 6-hour of sleep from 0:00 of the midnight to 6:00 in the morning at the environmental controlled room, where electrocardiogram (ECG) and blood pressure (BP) were measured, and saliva collection was made continuously in the time series. (RESULT) Salivary sIgA and alpha-amylase concentration obtained by saliva samples depicted a similar profile in the time series, i. e. gradually increase while subjects were asleep, and dropped to the initial level right after awakening. Meanwhile cortisol remained the same level while asleep and got started to increase right after awakening and reached at a peak around 40 minutes later. (CONCLUSION) We developed and proposed our own saliva collection technique for the purpose of non-invasive sample collection while asleep. As a developing result, the distinctive difference in the secretion of stress-related substances was illustrated;which might be derived from the difference in the stress-reaction pathways in our body.

著者

村松 正明

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.44, no.3, pp.403-409, 2006 (Released:2008-05-01)

参考文献数

5

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.43, no.Supplement1, pp.351-358, 2005-04-25 (Released:2011-09-05)

著者

Alper Bozkurt

出版者

一般社団法人日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.51, no.Supplement, pp.M-166-M-166, 2013 (Released:2013-09-06)

著者

Ryohei Kanzaki Ando Noriyasu Minigishi Ryo

出版者

一般社団法人日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.51, no.Supplement, pp.M-169-M-169, 2013 (Released:2013-09-06)

著者

Shinsuke Yamagishi Yoshihiro Masuda Yutaka Fukuoka Akinori Ueno

出版者

一般社団法人日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.51, no.Supplement, pp.R-15-R-15, 2013 (Released:2013-09-06)

著者

Chun Kit Alex Chan Hiroyuki Hamada KOHEI HIGUCHI Kazusuke Maenaka

出版者

Japanese Society for Medical and Biological Engineering

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.51, no.Supplement, pp.M-158, 2013 (Released:2013-09-06)

著者

Abhijit Suprem

出版者

Japanese Society for Medical and Biological Engineering

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.51, no.Supplement, pp.R-12, 2013 (Released:2013-09-06)

著者

本田 幸夫 高橋 里枝

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.48, no.6, pp.542-548, 2010-12-10 (Released:2011-06-07)

参考文献数

6