著者

丸山 敏弘 塩澤 成弘 牧川 方昭

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.1, pp.177-183, 2006 (Released:2008-02-27)

参考文献数

11

被引用文献数

1

---

Recently, much research has been done to evaluate mental stress based on heartbeat fluctuation and lower restraint, and a non-invasive ECG measurement method is been expected to be able to record the heartbeat during daily life. In this study, a new ECG measuring method that uses capacity coupled electrodes without any reference electrode is proposed. In this paper, five different settings of signal electrodes and ground connections were compared: One capacity coupled signal electrode with no ground electrode, two capacity coupled signal electrodes with no ground electrode, two capacity coupled signal electrodes with a common ground electrode on the skin, one capacity coupled signal electrode with one capacity coupled ground electrode, and two capacity coupled signal electrodes with the amplifier grounded. We also examined our new ECG measurement method under different electrical environments: in a noise-filled laboratory, outdoors with no commercial electrical power nearby, and inside a car with the engine and air conditioner operating. As a result, our new measurement method proved to be effective for obtaining ECG signals during daily life.

著者

川口 浩和 小林 哲生

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.4, pp.551-557, 2011-08-10 (Released:2012-01-18)

参考文献数

10

---

Eye-blink activities are major artifacts for electroencephalogram (EEG) measurements. Various methods have been reported for removing eye-blink artifacts from EEGs. Almost all previous methods focus on how much eye-blink artifacts are removed. However, they concurrently remove a part of EEGs together with eye-blink artifacts. Instead, we focus on how much true EEGs remains, and proposed a localized removal method for eye-blink artifacts. The proposed method is based on the combinations of independent component analysis (ICA). empirical mode decomposition (EMD) and Kalman filter. In addition, we proposed a novel simulation model to test performances of the proposed and previous methods. This simulation model indicates that the proposed method shows the best performance and reduces information loss of EEGs than previous methods.

著者

徳重 あつ子 阿曽 洋子 伊部 亜希 岡 みゆき 片山 恵

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.47, no.1, pp.15-27, 2009-02-10 (Released:2009-08-13)

参考文献数

43

---

This study examined the effect of sitting positions on cerebral activation for people in bed and analyzed postural significance. The subjects were 30 healthy adults. We recorded their EEGs in α and β band and performed a subjective test in supine and sitting positions with the head of the bed elevated at 30° and 80°. First, measurements were made in the supine position for 5 minutes, and the head of the bed was then elevated. Measurement continued in the sitting position for 15 minutes at 3 stages: Stages 1, 2, and 3. Using the supine position as a baseline, we compared the supine and sitting positions. We also compared the two angles, 30° and 80°. The EEG showed a significant increase at the 80° for all measured regions and intervals, and a partially significant increase was noted at 30°. Comparing the effect of different angles confirmed the significance of 80° at Stages 1 and 2. Moreover retention time of cerebral activation at 80° is longer than that at 30°. The subjective test also confirmed a higher degree of awakening in the sitting position and in a bed at 80°. Consequently, the effect of the sitting position verified cerebral activation.

著者

鶴岡 典子 河野 隆宏 松永 忠雄 永富 良一 芳賀 洋一

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.54, no.5, pp.207-217, 2016-10-10 (Released:2017-01-14)

参考文献数

20

被引用文献数

1

---

Quantitative measurement of sweating rate is a useful indicator of the state of autonomic nerves and related factors such as stress response or body temperature regulation. Specifically, it is known that mental stress increases mental sweating, and deep body temperature and dehydration increase thermal sweating. Therefore, continuous sweat measurement with a small sweating rate meter is expected to be useful for the management of mental stress as well as the prevention of heat stroke. In this study, two small sweating rate meters, one having high resolution and the other having a large dynamic range, were developed and used to measure mental sweating and thermal sweating. These devices determine the sweating rate by the conventional method, which measures the humidity difference between ambient air and air moistened by sweat. Measurement resolution and dynamic range can be adjusted by controlling the air flow rate. The device for measuring mental sweating rate consists of a main body, which has an air pump and two humidity sensors, and a capsule connected to the main body by tubes in which air flows. The device for measuring thermal sweating rate has a pump and two humidity sensors, an aperture instead of a capsule, and a flow channel on a flexible substrate. The mental sweating rates during arithmetic and speech tasks were measured on the plantar aspect of the big toe using the mental sweating rate meter. The present study on part of the sole showed two sweating types ; a reaction type and a low-reaction type. During the mental stress tasks, sweating rate increased by 0.43 mg/min/cm2 compared to that at rest in reaction type subjects, but by less than 0.1 mg/min/cm2 in low-reaction type subjects, showing very low responses to stimulations. The thermal sweating rate during immersion of the lower legs in warm water was measured using the thermal sweating meter worn on the forearm. Sweating rate increased by approximately 0.4 mg/min/cm2 on average due to thermal stress, and was also successfully measured. These results show that the small sweating rate meters developed in this study can be used for measuring mental and thermal sweating rates.

著者

土井 俊祐 井出 博生 竹内 公一 藤田 伸輔

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.55, no.1, pp.45-49, 2017-02-10 (Released:2017-04-25)

参考文献数

9

---

Personal Health Records (PHRs), a system that enables people to manage, share, and apply personal healthcare data using information and communication technology, is expected to be an effective method to realize a vigorous society with longevity. However, it is not clear how the user's opt-in agreement and self-management of personal data may be achieved. Thus, we developed a new method to optimize opt-in agreement and access control for users in a PHR developed at Chiba University, the Social Health Assist Chiba (SHACHI). In SHACHI, participating facilities such as hospitals, clinics, pharmacies, and nursing care services display a user's unique two-dimensional bar code on a web browser. The user reads the bar code by him/herself using the “SHACHI App,” which is installed on his/her smart phone beforehand. SHACHI considers this process to signify the user's opt-in agreement. Moreover, users can retract or resume this agreement using the SHACHI App at any time. This system enables the users to self-manage personal data in PHRs. The new system satisfies government requirements and the conditions required for PHR presented in a previous study. This new system can be adopted easily by other PHRs. We plan to identify the required functionalities of standard PHRs and secondary utilization of data stored in PHRs which may be managed through the new system.

著者

熊橋 智史 野川 雅道 内藤 尚 田中 志信

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.54, no.26, pp.S109, 2016

---

<p>Toward a development of noninvasive tissue oxygen consumption monitoring method, we propose an arteriovenous blood oxygen saturation measurement based on near-infrared spectroscopy. For arterial blood oxygen saturation measurement, we employ a conventional arterial blood oxygen saturation measurement method, pulse oximetry. Then, for venous blood oxygen saturation measurement, based on a similar principle of pulse oximetry, we developed a new venous blood photoplethysmographic oximetry using cyclic cuff compression technique (mean pressure: 10mmHg with 10mmHg amplitude, cyclic frequency: 0.1Hz). The noninvasive arteriovenous blood oxygen saturation measurement system comprises two-wavelength, 750/830nm. The calibration curve of blood oxygen saturation measurement was calibrated, without blood-drawing, using theoretical photon propagation model based on radiative transfer. The newly designed noninvasive arteriovenous blood oxygen saturation measurement system was evaluated with healthy subjects' forearms during isometric hand-grip exercise. The noninvasive measurement system could offer reasonable blood oxygen saturation changes during the exercise and following resting period.</p>

著者

中村 のぞみ 栁澤 一機 綱島 均 成田 奈緒子

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.53, no.Supplement, pp.S383-S386, 2015 (Released:2016-06-18)

---

BCI (Brain Computer Interface) is a system that controls machines and devices by extracting neural information from human brain activity and inputting it to machines. BCI system can be used to feedback the brain activity level to users so that they can control their brain activity, which is called NFB (Neurofeedback). The NFB system is expected to make better condition for ASD (Autistic spectrum disorder) and ADHD (Attention deficit hyperactivity disorder) patients. The NIRS-NFB system measures the brain activity by using portable NIRS. The measured brain activity can be inputted to various machines and devices (display monitor, toy car and video game). To evaluate the effectiveness of the developed system, we conducted experiments of NFB training for ASD participants. It is shown that more brain activity can be observed after the NFB training for ASD participants. Those results show that the developed system is effective in the NFB training for ASD participants.

著者

京相 雅樹

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.1, pp.47-53, 2006 (Released:2008-02-27)

参考文献数

101

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.45, no.Supplement1, pp.101-102, 2007-04-25 (Released:2011-09-05)

著者

清水 孝一

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.1, pp.1-2, 2006 (Released:2008-02-27)

被引用文献数

2

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

---

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

---

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

---

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.

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)

---

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

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

---

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

---

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)

---

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

---

(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.