著者

木村 裕一 堀江 亮太

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.1, pp.51-57, 2014-02-10 (Released:2014-05-22)

著者

山越 健弘 田中 直登 山越 康弘 松村 健太 ROLFE Peter 廣瀬 元 高橋 規一

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.48, no.5, pp.494-504, 2010-10-10 (Released:2011-05-27)

参考文献数

19

被引用文献数

1

---

Motor racing athletes in the closed-cockpit category are always facing life-threatening situations caused by heat stroke, especially in hot weather. We report here the development of a novel infrared-radiation-type eardrum thermometer, with a built-in earphone, which can be used for continuous measurement in GT car racing. We examined the accuracy of the system for core body temperature monitoring in 10 healthy volunteers (21.8 ± 1.0 (S.D.) yrs) using a temperature controlled water bath. In addition, we assessed the usefulness of the system under real racing conditions with 2 professional drivers in the practice session of 2010 SUPER GT International Series Round 4 MALAYSIA being held at the Sepang International Circuit. To examine accuracy two thermistor probes, one inserted into the ear canal and the other beneath the tongue, were used for measurements of eardrum and sublingual temperatures respectively. An infrared eardrum thermometer was inserted into the contra-lateral ear canal. The measured temperatures were recorded at 30-s intervals. The results showed good correlation between the infrared eardrum temperature and both the direct eardrumtem temperature (r = 0.994, n = 1119, p < 0.001) and the sublingual temperature (r = 0.972, n = 1119, p < 0.001). The mean difference between these temperatures was + 0.09 °C, - 0.08 °C, and 1.96 S.D. was 0.21 °C, 0.44 °C, respectively. As for the field test, the system functioned satisfactorily during real racing conditions performed on the racing circuit. These results suggest that our new system can be used in a race setting as a reliable core temperature monitor and could help to improve safety of motor sports.

著者

河内 了輔 新川 拓也 河原崎 景太 藤川 智彦 武井 安津子 湊 小太郎

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.50, no.6, pp.564-570, 2012-12-10 (Released:2013-07-31)

参考文献数

12

被引用文献数

1

---

In this study, we developed a point-contact force sensor, and this sensor was used to develop a measurement system that was shaped in the form of a feeding bottle. Unlike in a cantilever force sensor, in the proposed force sensor, the point of force measurement does not move. Thus, the force sensor can measure a force at a specified point. The force sensor consists of a pressure transducer and a steel ball with a diameter of 3 mm. Any force applied to the artificial nipple is transmitted to the pressure transducer, which is in point contact with the steel ball. The force sensor is linear up to a load of 3.92 N, has a hysteresis of 1%, and has a response time of 4 ms. The force is measured at distances of 8 mm (channel 1) and 14 mm (channel 2) from the tip of the nipple. In the measurement system, the sensor signals are converted (A/D) at a sampling rate of 100 Hz and a quantization resolution of 10 bits. After the A/D conversion, the force signals are transferred to a data indicator and a data logger for real-time display on an LCD and for storage ona micro SD card, respectively. Using this system, we performed measurements on four infants. A signal peak was observed from channel 2 and then from channel 1. This result could be attributable to the peristaltic movements of the infant's tongue. The same result was observed for all subjects. These results indicate that the proposed system can be used to measure any force that is applied to an artificial nipple. Moreover, the mother of a subject also performed measurements using the system. This confirmed that the system was easy to operate and that measurements could be performed in a normal feeding posture.

著者

出町 文 重原 伸彦 江田 廉 澤口 冬威 望月 剛 桝田 晃司 宮本 義孝 千葉 敏雄

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.51, no.6, pp.374-383, 2013-12-10 (Released:2014-03-28)

参考文献数

20

被引用文献数

2

---

We have previously reported our attempts for active control of microbubble aggregations, by making use of Bjerknes force, which acts to propel microbubbles and to adjust the size of aggregations. However, because we have used simple shape of artificial blood vessels, the behavior of aggregations in a capillary, e.g., probability to obstruct in bloodstream, possibility of embolization, has not been predicted. Thus we measured the sticked area of produced aggregation on a wall of artificial blood vessel before evaluating the volume flown to downstream. First we prepared the straight path model of artificial blood vessel with the diameter of 2 mm to produce aggregation by emitting ultrasound against flow, which conditions were with 5 MHz and 300-500 kPa-pp. The size of aggregation increased according to the sound pressure, whereas there would be an optimal flow velocity and suspension density to obtain maximum trapped performance. The flat rate of aggregation showed that sound pressure works to compress the shape of aggregation rather than the effect of flow velocity. Then we derived the conditions to obtain a desired volume of aggregation to apply to the multi-bifurcation model of artificial blood vessel, which has repeatedly divided paths until the middle of the model from the inflow path of 2 mm to the minimum diameter of 0.5 mm, to confirm the behavior of an aggregation. Using the flow velocity of 20 mm/s, maximum sound pressure of 300 kPa, and suspension density of 0.08 μl/ml, the volume of aggregation was expected to be 0.6 mm3, which is greater than the section area of the narrow path in the bifurcation model. The result showed that the aggregation, in 50 s after the injection of the suspension, flaked off the vessel wall, flew to downstream, and was caught at a bifurcation. Finally we clearly confirmed that the aggregation blocked a path, where colored water could not penetrate to downstream.

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.Supplement1, pp.330-334, 2006-05-15 (Released:2011-09-05)

著者

小林 直樹 田村 俊世 湊 小太郎

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.51, no.1, pp.31-37, 2013-02-10 (Released:2013-09-10)

参考文献数

8

---

In the principle model of pulse oximetry, the measured absorbance change occurs by a thickness change of the arterial blood. However, we cannot explain the absorbance change of the tissue only by thickness change of the arterial blood when we consider these three phenomena of circulatory dynamics:1) arterial blood flows into the tissue as pulsatile flow, 2) Oxygen saturation decreases by oxygen consumption in the tissue, and 3) venous blood flows out from the tissue. In this study, we made a new electrical model of pulse oximetry and examined the mechanism of the absorbance change when the height of the hand is changed. We measured absorbance ratio and SpO2 at three vertical hand positions, 1) on the table (middle), 2) rise over the head (up), 3) lowered (down), with six healthy volunteers. The absorbance ratios increased in the lowered hand position and there was an error to underestimate SpO2. The mean ± SD of SpO2 in the 6 subject at the middle, up, and down positions were 98.0 ± 1.28, 98.4 ± 0.84, 96.3 ± 1.69(%), respectively. We simulated pulse oximetry using our new electrical model, and we were able to express a mechanism to increase the absorbance ratio at the lowered hand position.

著者

小林 直樹 濱田 雅美

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.51, no.1, pp.17-23, 2013-02-10 (Released:2013-09-10)

参考文献数

13

---

Visual induced motion sickness (VIMS) due to real videos (passive videos) has been well evaluated by using a set of RR intervals (RRI) on electrocardiograms (ECG). However, in case of the estimation of VIMS for interactive videos suchas video games, it is difficult to obtain a stable VIMS index by using only RRI because of several modulation factors by respiration and personal errors among individual operations. For the evaluation of VIMS on interactive videos we propose VIMS quantification indices that use principal component analysis (PCA) of two time-variant biosignals, RRI and respiration signal (RESP), respectively. As VIMS indices we introduced frequency components of a score (rr) and a score (resp), which are time-variant scores resulting from PCA of the biosignals. The experimental results were estimated by regression analysis between the proposed indices and simulator sickness questionnaire (SSQ) or global motion vectors (GMVs) of videos. The experimental results show that a positive correlation is shown between the index of the score (rr) frequency analysis and SSQ for both passive and interactive videos. Because there are no significant difference between the indices for interactive video and for passive videos, the index does not influence operation factors, and reflects biomedical influence caused by video features such as GMVs. This means that the index calculated by score (rr) is effective for quantifying the VIMS caused by video factors, even though the dispersion of the index caused by the subject's individuality is not sufficiently small. This index also influenced the individuality of the subject's game habituation. On the other hand, there is little correlation between the index of the score (resp) frequency analysis and SSQ for each type of video. As a dependency of the operation and personal errors might be included in this index, we need to study more detail about this component.

著者

本井 幸介 中村 心也 田中 直登 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.51, no.4, pp.268-275, 2013-08-10 (Released:2013-12-11)

参考文献数

25

---

Recently, the freak accidents in home have been increased and they are caused by the asphyxiation, drowning, falling, fire, and toxicosis. Especially in bathroom, the accident frequently arise and thus the healthcare monitoring and the accident detection system can be useful for attainment of safe and untroubled daily life. While some monitoring systems for moving state using infrared ray and ultrasonic wave were already developed, these methods distinguish only whether or not a bather is moving. Also, detailed motion analysis using CCD camera has the problem of privacy for the practical use. From these viewpoints, we designed the monitoring system for the electrocardiogram and respiration signal using bathtub-installed electrodes, showing its usefulness for the healthcare and the drowning alarm during taking a bath. However, the range over which this method is possible is limited in the bathtub and thus the detection in washing place are impossible. To solve this drawback, we developed a new system capable of detecting the accident in the washing place together with the pulse and respiration rate using a bath mat type multipoint pressure sensor located in washing place of bathroom. From the results of the accuracy evaluation in 20 healthy subjects, it is demonstrated that the present system can accurately detect the accident [60/60, 100%]and show the good correlation between the pulse [r=0.99] and respiration [r=0.95]obtained from the system and those obtained from the conventional methods using the sensors attached to the body surface.

著者

山口 昌樹 花輪 尚子 吉田 博

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.2, pp.161-168, 2007 (Released:2008-08-08)

参考文献数

26

被引用文献数

10

---

In order to realize a novel handheld monitor for the sympathetic nervous system, we fabricated an analytical system for salivary amylase activity (sAMY) using a dry-chemistry system called a “Cocoro Meter.” The device to quantify sAMY using an activity rate method was completely automated. This method was made possible by the fabrication of a disposable test-strip equipped with built-in salivacollecting and reagent papers, and an automatic saliva transfer mechanism. Within a range of sAMY between 0-200 kU/l, the calibration curve for the monitor showed a coefficient of R2=0.988 and CV (coefficient of variation) of 10.2%. The reproducibility between devices was within 10%. Moreover, it was demonstrated that: (i) the quantitativity of the sample collected by the test-strip was sufficient, (ii) the sublingual area was suitable as the sampling site of the saliva, and (iii) 30 s was sufficient for saliva sampling. Considering all of these effects including the saliva sampling site, a 12.1% CV was obtained for this monitor. A total of 1 min was sufficient to analyze the sAMY. Thus, this study demonstrated that the monitor might be used as a good index for psychological research.

著者

城 和男 萩原 啓

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.7-14, 2009-02-10 (Released:2009-08-13)

参考文献数

16

被引用文献数

1

---

The present study was conducted in order to clarify the features of the occurrences of body movement during nighttime sleep and estimate the depth of sleep. Sleep experiments were conducted on seven healthy, non-medicated subjects, aged20-23years (5 males and 2 females) for 7 hours. During sleep, body movement was measured by electroencephalography (electroencephalography body movement: EEGBM) and by a passive infrared type motion sensor (NapVIEW body movement: NapVIEWBM) . Among all subjects, the mean concordance rate between EEGBM and NapVIEWBM was 0.95 ± 0.03. This finding suggests that it is possible to measure body movement with a 90% or greater concordance with EEGBM using a non-contact method, such as NapVIEW. Analysis of the relationship between body movement intervals and depth of sleep showed that the interval between body movements was longer during deep sleep and shorter during light sleep. Sleep state was evaluated based on data obtained by detailed analysis of the interval between body movements. Linear discriminant analysis was conducted on the interval data obtained by NapVIEWBM to divide into a group of light sleep stages and a group of deep sleep stages. A concordance rate of 90.5% between estimated depth of sleep and actual sleep stage was obtained during light sleep, while a concordance rate of 70.8% was obtained during deep sleep. These findings indicate that sleep state can be adequately evaluated based on depth of sleep as indicated by body movement.

著者

神谷 暸

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.324-325, 2011-04-10 (Released:2011-12-14)

著者

林 達郎 周 向栄 陳 華岳 原 武史 藤田 広志 横山 龍二郎 兼松 雅之 星 博昭

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.46, no.4, pp.451-457, 2008-08-10 (Released:2009-01-21)

参考文献数

11

---

The number of osteoporosis patients is increasing every year in Japan. Bone mineral density (BMD), which is the helpful feature quantity in diagnosing osteoporosis, is generally measured in the central part of the vertebral body. It's possible to measure BMD at each location in X-ray CT images having a high spatial resolution. If bone mineral density of the vertebral body is not homogeneous, grasp of the lower BMD location inside the vertebral body may be helpful to clinical diagnosis. In this paper, using X-ray CT images of 80 subjects (40 male and 40 female subjects), BMDs of trabecular bones from the 12th thoracic vertebra to the 1th sacral vertebra (S1) were measured at each location. The present study showed that anterior and central locations of thoracolumbar and lumbar vertebra, and posterior, inferior, and central locations of S1 had lower BMD values. Therefore, at the thoracolumbar and lumbar vertebra, if the BMDs of anterior or central locations are selectively measured, prediction of fracture risk at vertebral bodies could be improved.

著者

神林 優太 萩原 啓

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.50, no.1, pp.99-104, 2012-02-10 (Released:2012-07-13)

参考文献数

24

---

Accurate assessment of the sleep cycle at home will improve self-awareness regarding the necessity of sleep for relieving fatigue. Previous studies have shown that a large number of body movements occur during light sleep compared to deep sleep. In the present study, sleep was assessed by monitoring body movements using an infrared motion sensor and Polysomnography (PSG) for a 420-min period from 00:00 to 07:00. The findings of sleep cycle based on body movements were compared with PSG findings. One cycle of sleep cycle was defined as a set of “REM, sleep level 1, 2, 3 or 4” period and subsequent “SWS, sleep level 5 or 6” period. We defined Body Movement Density (BMD) as an index of sleep cycle. BMD was a value representing the number of body movement occurrences during a 30-minutes period. The cross-correlation coefficient between BMD and sleep levels was significant in all subjects (13 males, 3 females;age, 20-23 years). In this study, a concordance rate of 76.9% (SD±24.0) between BMD cycle and sleep cycle was obtained. This study indicates the possibility of estimation for sleep cycle by using BMD without using PSG. One of the greatest advantages of BMD is that it comprises only body movement data, so measurements of breath, heart rate or brain waves are not required. Moreover, measuring BDM is both inexpensive and noninvasive.

著者

桑江 豊 三好 寿顕 関根 正樹 辻 美和 藤元 登四郎 田村 俊世

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.50, no.6, pp.535-542, 2012-12-10 (Released:2013-07-31)

参考文献数

17

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This study was performed to examine the effects of weekly exercise in subjects classified as support_1 according to the Japanese health care insurance system. We evaluated the ability of eight elderly subjects to walk using wireless inertia sensors with an embedded triaxial accelerometer and angular velocity sensor. The subjects participated in training once a week and were evaluated once a month over a study period of 3 months. Wearable motion sensors were attached to the lower back and both thighs of each subject. The subjects performed high-performance walking over a distance of 10 m. The speed, cadence, gait cycle, thigh pitch angle, and autocorrelation function on the lower back were determined. The subjects attained high-performance walking sooner after 3 months. Although most of the subjects showed an improvement in walking ability, there were no significant improvements in the cadence gait cycle or autocorrelation function. Exercise once a week can significantly improve the ability of elderly subjects to walk. Thus, home exercise is recommended to improve walking ability in the elderly.

著者

中村 透 山本 松樹 佐藤 弥

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.2, pp.197-206, 2010-04-10 (Released:2011-01-08)

参考文献数

18

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In this study, we investigated whether psychological states in an environment with visual stimuli can be modeled by physiological indices. As visual stimuli, films to elicit various types of emotions were presented. First, psychological ratings in response to these stimuli were investigated using semantic differential scales. Principal component analysis for the psychological ratings confirmed two primary components, which could be interpreted as the valence and arousal dimensions reported in previous studies. Then, while viewing these stimuli, psychological ratings and multiple central (electroencephalogram (EEG) and near-infrared spectroscopy (NIRS) ) and peripheral (heart rate (HR), skin potential level (SPL), respiration, thermogram, plethysmogram, and eye blinks) physiological activities were measured. Stepwise regression analyses revealed that the psychological valence could be accounted for by indices of the EEG, NIRS and HR. Psychological arousal was also explained by activities of the EEG and SPL. These results suggest that the psychological states in the visual stimulus environment could be modeled by the physiological indices.

著者

比嘉 広樹 堂上 高司

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.1, pp.31-36, 2008-02-10 (Released:2008-09-29)

参考文献数

8

被引用文献数

1

---

A noncontact input interface using image processing for people with disabilities of the fingers, such as rheumatism, collagen disease, and osteoarthritis, has been developed. The input interface is simply composed of a CCD camera and PC. Taken with the CCD camera, the fingers were appropriately detected using image processing in this paper. An on-screen keyboard and control box were also made. In order to evaluate a performance of the input interface, three healthy subjects input some example sentences using it. From the experimental results, it was clear that the beginners could directly input them in Microsoft Word without any difficulty, and the input characteristics with the least error were experimentally shown in this paper.

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.Supplement1, pp.286-291, 2008-05-08 (Released:2011-09-05)

著者

福島 大志 西川 敦 宮崎 文夫 関野 正樹 安室 喜弘 松崎 大河 細見 晃一 齋藤 洋一

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.49, no.1, pp.122-131, 2011

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Repetitive Transcranial Magnetic Stimulation (rTMS) is effective for intractable diseases of the nervous system. As the effects of rTMS last only several hours, rTMS therapies need to be continued daily. Under present circumstances, it is difficult to use rTMS in patients' home, because only experienced physicians in limited hospitals can use the expensive and complicated rTMS system. Therefore, we developed a magnetic navigation system for home use of rTMS. The proposed system uses inexpensive and small magnetic sensors; hence it is suitable for home use. By using the proposed method, even people who have no medical knowledge and technique can easily navigate the coil to the optimal position preliminarily specified by expert physicians. Our system needs to collect some dataset which consists of magnetic field and the corresponding position of the coil at the patients' initial visit. Since it is bothersome to collect a large number of dataset, we reduced the dataset by approximation using multi-regression analysis.

著者

清水 佐知子 大野 ゆう子 岩佐 真也 尾島 裕子 林 剣煌 冨澤 理恵 大西 喜一郎 本杉 ふじゑ 岡田 千鶴

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.536-541, 2010-12-10 (Released:2011-06-07)

参考文献数

12

被引用文献数

1

著者

横内 光子 大野 ゆう子 笠原 聡子 沼崎 穂高 石井 豊恵

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.43, no.4, pp.762-768, 2005 (Released:2007-01-19)

参考文献数

16

被引用文献数

3

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To assure security and reliability for medical services under the conditions of limited financial and human-resources, it is important to develop a quantitative method for adequate scheduling of each medical task provided by medical staff. In this paper, we developed a task classification system for medical staff from the view-point of job scheduling and applied it to actual clinical nursing time-motion study data. Based on the interview data from the three trained nurses working in a surgical ward, four scheduling points were drawn by ethnomethodological word mining ; [indispensability], [expectation], [laborforce for operation], and [time dependency]. The time-motion study data of one nurse working in a surgical ward during the daytime was analyzed from this point of view ; the nurse was in charge of five patients including one patient scheduled for surgery. The results were : (1) Almost all tasks related to major demand (e.g.,, transfer of patient to the operating room) with high indispensability and expectation, and time dependency ; (2) Required much time to complete the task (e.g., time required to transport the patient to the operating room), or were jobs with low time dependency that were selectively carried out ; (3) Required answering a nurse-call or telephone, which was classified into a task with high time dependency. In the analysis, some jobs were arranged in the order of inefficiency, contrary to the scheduling classification. The classification showed good consistency with the clinical decisions on scheduling nursing services, and the results explained well the way of scheduling nurse's duties.