著者

今井 文吾 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.148-155, 2006 (Released:2008-02-27)

参考文献数

10

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In this study, to eliminate the motion artifacts contaminating photoplethysmograpic (PPG) signals, a clip-type earlobe photoplethysmography sensor was improved and a noise-reduction algorithm based on a multiple-regression model was examined. Motion artifacts are thought to be caused by a change in the flow of blood. We thought that such motion artifacts could be reduced considering the acceleration change during body motion. In this study, an acceleration sensor was integrated with a commercially available clip-type earlobe PPG sensor. For the first step, typical motion artifact waveforms were calculated by choosing every motion artifact waveform, arranging the peak time and averaging. In the second step, to make a multiple regression analysis between averaged acceleration and averaged motion artifact waveform, regression coefficients were calculated. Finally, an original PPG signal with motion artifact was filtered using an individually adjusted multiple regression model. In experiments, five subjects were asked to walk and run on a treadmill to verify this filtering method. Results show that our new motion artifacts reduction algorithm is proven to be effective for decreasing the influence of body motion, and the detection accuracy of the number of pulsations has improved up to 13.3%.

著者

岡田 志麻 藤原 義久 松浦 英文 安田 昌司 水貝 浩二郎 牧川 方昭 飯田 健夫

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.41, no.4, pp.493-497, 2003-12-10 (Released:2011-09-05)

参考文献数

6

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Sleep is very important to keep our physical condition healthy. Many studies have been devoted to clarify the mechanism of sleep and to monitor the sleep all night. In this study, we paid attention to heart activity during sleep and have developed a nonrestraint monitoring method of heart activity using an acceleration sensor set inside the coverlet. This method is easy for the use of sleep monitoring at home in daily life. An acceleration sensor was set inside the coverlet as it opposing to subject's left chest. Subjects were asked to lie in supine position and the coverlet with an acceleration sensor was put on the subject. Mechanical vibration from heart activity expected to be carried to the acceleration sensor through the coverlet. As a result, periodic vibration was measured successfully and this vibration was proved to be in high correlation with the R wave of ECG in six subjects. The same results were obtained even in case of lying in right and left lateral decubitus position.

著者

萩 浩司 牧川 方昭 飯泉 仁美

出版者

一般社団法人電子情報通信学会

雑誌

電子情報通信学会技術研究報告. MBE, MEとバイオサイバネティックス

巻号頁・発行日

vol.95, no.291, pp.1-8, 1995-10-13

被引用文献数

1

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本研究は生体内にコンピュータならびに計測回路などの,生体内信号の直接計測に必要な一切の要素を埋め込むことを最終目標とし,今回はこのような体内コンピュータ実現に不可欠な要素である皮膚を介した情報通信の方法,電力供給の方法について検討を行った.体内と体外のコンピュータ間の経皮ディジタル通信は赤外線を用いたシリアル通信を検討し,皮下に赤外発光ダイオードおよび受光センサを埋め込むことにより体内・体外間の双方向ディジタル通信が可能であることが明らかとなった.また経皮的電力供紿に関しては皮膚表面に一種のトランスを形成することにより実現できることが確認された.

著者

萩 浩司 牧川 方昭 飯泉 仁美

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.4, pp.334-342, 1995 (Released:2011-10-14)

参考文献数

19

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In this study we have developed a transcutaneous digital communication technique by using Pulse-Code-Modulated (PCM) infrared rays. The communication protocol examined here is serial, asynchronous and half duplex. The electric power should be considered for a computer system implanted inside the body, because it is driven by batteries and the power is insufficient. Its size should also be miniaturized as small as possible. Therefore the following methods were adopted here; the weak infrared rays emitted inside the body were received by a high sensitive avalanche photodiode; the infrared rays of high brightness was used to send data into inside of the body; and the digital data were converted into an optical signal after the pulse-code-modulation (PCM). This modulation yields some advantages; 1) absorbing the response delay of the photosensor, 2) intensifying infrared rays luminescence outside body and 3) saving the electric power on the luminescence inside body. Some communication experiments were done by using pork with the skin; the communication speed was 9600 baud from inside to outside and 1200 baud in the opposite direction, 15 infrared LEDs were set for outside of the body, 4 for inside, three nickel hydride batteries of 1200mAh were used for an electric power inside the body. As a result, a stable bi-directional digital communication was realized through the skin and the pork of about 9cm and it could continue to operate for about 19 hours.

著者

牧川 方昭

出版者

一般社団法人 日本生体医工学会

雑誌

BME (ISSN:09137556)

巻号頁・発行日

vol.15, no.1, pp.26-30, 2001-01-10 (Released:2011-09-21)

参考文献数

7

著者

羽生 能行 牧川 方昭 石原 謙

出版者

The Society of Instrument and Control Engineers

雑誌

計測自動制御学会論文集 (ISSN:04534654)

巻号頁・発行日

vol.32, no.5, pp.628-636, 1996-05-31 (Released:2009-03-27)

参考文献数

19

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In this paper, we have tried to measure physiological responses under mental stress in some daily scenes with a portable digital biosignal memory device. The aim of this study is to search for the method to evaluate objectively the mental stress in daily life. Here we chose the heart rate and the respiratory rate as non-invasive measuring objects and have developed an ambulatory mental stress monitoring system. Daily life stress scenes used here was the graduation thesis presentation, an unexpected police checkup during a car driving and the getting on a roller coaster, and in addition the calculation experiment under the laboratory was done for the comparison with other previous results reported.As a result, the heart rate and the respiratory rate were getting higher, and the respiration was getting irregular under strong mental stress, that is, getting on a jet coaster, presenting a graduation thesis, and a police checkup while driving. Under weak stress, like the calculation in the laboratory and the car driving, the respiratory rate was getting higher and irregular, but the heart rate wasn't remarkably high. From these results, it was suggested that the heart rate, the respiratory rate, and the respiratory irregularity are effective to evaluate the mental stress in daily life.

著者

村上 元庸 小島 保二 前田 敏博 牧川 方昭 福田 眞輔

出版者

Japan Shoulder Society

雑誌

肩関節 (ISSN:09104461)

巻号頁・発行日

vol.15, no.1, pp.4-8, 1991

被引用文献数

2

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Sensory nerve endings in the monkey shoulder joint capsule were observed by light microscopy. The nerve staining technique was based upon Tago's method which was very sensitive for acetylcholinesterase (Ach E) existing in the peripheral nerve.<BR>Three distinct sensory nerve endings have b een identified: free nerve endings, Ruffini-type corpuscles, and Pacini-type corpuscles.<BR>Ruffini-typc corpuscles a n d Pacini-type corpuscles, which were thought to act as mechanoreceptors, were mainly localized in the transitional portion between the labrum and the capsule, but not within the labrum.<BR>Free ne r ve endiings, which may function as nociceptors (Pain), were distributed widely in the capsule and also in th labrum.<BR>As the results demo n strated that may mechanoreceptors exist in the capsule, it is presumed that the capsule acts not only as a static stabilizer, but also as a sensory apparatus for stress, and plays an important role in the dynamic stabilizing system. It seems that the location of the mcchanoreceptors is the optimum place for sensors to respond to the resultant force which dislocates the humeral head.<BR>Finally, we hypothesize that the dynamic stabilizing effect is performed by a series of reflex effects from the capsule to the surrounding muscle of the shoulder.

著者

村上 元庸 牧川 方昭 前野 幹幸 畑 正樹 七川 歓次

出版者

日本肩関節学会

雑誌

肩関節 (ISSN:09104461)

巻号頁・発行日

vol.10, no.1, pp.22-24, 1986-07-28 (Released:2012-11-20)

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When abducting the arm, the scapula and the humerus move cooperatively. This cooperation is known as “scapulohumeral rhythm”, and a constant relationship is said to exist between the abduction angle of the humerus and that of the scapula.But since the glenoid is too small to support the humeral head, it may happen that the humeral head will be dislocated or the soft tissue, like tendons or capsule, will be exposed to a excessive load, if the resultant force through the humeral head does not directly face to the glenoid. So we guess that a change of the resultant force which is consist of load and muscle power to the humerus may change the incline of the glenoid even at the same humeral abducting angle.In this study, we investigated the relationship between the glenoid inclination angle and the humeral abduction angle with or without block of the supraspinatus muscle power by the suprascapular nerve block.The subjects of this experiment was 5 healthy men, and the angle was measured by X-ray films which were taken at every 45 degrees abduction position with voluntary effort to abduct isometrically before and after the nerve block, and also the abduction torque was measured simultaneously by the Cybex- II.The result was that the inclination angle of the scapula was decreased after block, as the maximum defference at 90 degree abduction by 6 degree. And the torque was decreased by the mean of 25 %.From our hypothesis that the resultant force faces the glenoid perpendicularly, these results could be explained by the functional anatomy of the supraspinatus tendon. At 0 and 135 degree abduction the supraspinatus runs perpendicularly to the glenoid, so the resultant force does not change the direction after block. But at 90 degree abduction the position of the insertion of the supraspinatus is the highest of all abduction angle, so it acts to pull down the head. The resultant that force after block changes the direction upward, and so the glenoid inclination angle decreases to face the head.From these results, we guess a resultant force to the humeral head always faces to the glenoid by controlled constraction of the muscles around the shoulder.

著者

藤原 義久 冷水 一也 源野 広和 松浦 英文 安田 昌司 飯田 健夫 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.43, no.1, pp.162-171, 2005

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This paper describes the development of a sensor incorporating an algorithm that estimates the quality of comfortableness by measuring peripheral skin temperature, pulse, and galvanic skin response (GSR) that reflect autonomic nervous system activity. A correct answer rate of 83% was obtained between the subjective comfortableness and the estimated comfortableness by the developed sensor. For the application of this human feeling sensor, we used it to estimate the comfortableness of subjects receiving massages, then developed two alternative adaptive massage control procedures based on the sensor's estimate, and verified the effectiveness of the results through testing the subjects. We observed that in course A (dynamic comfortableness) the peripheral skin temperature dropped and the GSR and pulse rate increased, while in course B (static comfortableness) the peripheral skin temperature rose and the GSR and pulse rate dropped. By the end of the control sequence, there was a statistically significant difference in the amounts of change in both the peripheral skin temperature and the GSR between the two sequences (<i>p</i> < 0.05). To examine the effects of each course more closely, we mapped the trajectories of physiological change during the control sequences of each course at twentysecond intervals, and the results correlated closely with the subjective assessments. These results suggest that bio-control adapted to comfortableness is feasible.

著者

三上 博史 坂上 友介 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.53, no.5, pp.264-269, 2015

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Knee joint injuries frequently occur in individuals performing sport activities. Knee taping is found to reduce the burden on knee ligaments, particularly the patellar tendon. However, methods for quantitative verification of the kinetic effects of taping on the patellar tendon are limited. In this study, a measurement method using ultrasound imaging was developed to quantify the effects of knee taping on the patellar tendon, and the effects were verified in healthy subjects. The experiment was conducted under five conditions:no taping on the knee joint and taping by four different methods. To verify the differences in taping effect on the patellar tendon under five experimental conditions, we calculated the stress-strain curve from the cross-sectional area and elongation of the patellar tendon acquired using ultrasound imaging. Twelve healthy men (aged 22.6&plusmn;1.1 years) participated in the experiment. Each subject was asked to sit on a chair with the knee joint flexed at 90&deg;, extend the knee joint, and maintain the extension force for 3 s. During the last isometric contraction, the extension force was changed from 40, 80, 120, 160N to the maximum voluntary extension force of each subject. We succeeded to measure the elastic modulus of the patellar tendon under knee taping condition. The stress-strain curve under no taping condition was significantly different from all four taping conditions (<I>p</I><0.05).

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

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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

岡田 志麻 藤原 義久 松浦 英文 安田 昌司 水貝 浩二郎 牧川 方昭 飯田 健夫

出版者

社団法人日本生体医工学会

雑誌

生体医工学 : 日本エム・イー学会誌 (ISSN:1347443X)

巻号頁・発行日

vol.41, no.4, pp.493-497, 2003-12-10

---

Sleep is very important to keep our physical condition healthy. Many studies have been devoted to clarify the mechanism of sleep and to monitor the sleep all night. In this study, we paid attention to heart activity during sleep and have developed a nonrestraint monitoring method of heart activity using an acceleration sensor set inside the coverlet. This method is easy for the use of sleep monitoring at home in daily life. An acceleration sensor was set inside the coverlet as it opposing to subject's left chest. Subjects were asked to lie in supine position and the coverlet with an acceleration sensor was put on the subject. Mechanical vibration from heart activity expected to be carried to the acceleration sensor through the coverlet. As a result, periodic vibration was measured successfully and this vibration was proved to be in high correlation with the R wave of ECG in six subjects. The same results were obtained even in case of lying in right and left lateral decubitus position.

著者

藤原 義久 冷水 一也 源野 広和 松浦 英文 安田 昌司 飯田 健夫 牧川 方昭

出版者

社団法人日本生体医工学会

雑誌

生体医工学 : 日本エム・イー学会誌 (ISSN:1347443X)

巻号頁・発行日

vol.43, no.1, pp.162-171, 2005-03-10

参考文献数

20

被引用文献数

2

---

This paper describes the development of a sensor incorporating an algorithm that estimates the quality of comfortableness by measuring peripheral skin temperature, pulse, and galvanic skin response (GSR) that reflect autonomic nervous system activity. A correct answer rate of 83% was obtained between the subjective comfortableness and the estimated comfortableness by the developed sensor. For the application of this human feeling sensor, we used it to estimated the comfortableness of subjects receiving massages, then developed two alternative adaptive massage control procedures based on the sensor's estimate, and verified the effectiveness of the results through testing the subjects. We observed that in course A (dynamic comfortableness) the peripheral skin temperature dropped and the GSR and pulse rate increased, while in course B (static comfortableness) the peripheral skin temperature rose and the GSR and pulse rate dropped. By the end of the control sequence, there was a statistically significant difference in the amounts of change in both the peripheral skin temperature and the GSR between the two sequences (p<0.05). To examine the effects of each course more closely, we mapped the trajectories of physiological change during the control sequences of each course at twentysecond intervals, and the results correlated closely with the subjective assessments. These results suggest that bio-control adapted to comfortableness is feasible.

著者

藤原 義久 冷水 一也 源野 広和 松浦 英文 安田 昌司 飯田 健夫 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.43, no.1, pp.162-171, 2005 (Released:2007-01-19)

参考文献数

20

---

This paper describes the development of a sensor incorporating an algorithm that estimates the quality of comfortableness by measuring peripheral skin temperature, pulse, and galvanic skin response (GSR) that reflect autonomic nervous system activity. A correct answer rate of 83% was obtained between the subjective comfortableness and the estimated comfortableness by the developed sensor. For the application of this human feeling sensor, we used it to estimate the comfortableness of subjects receiving massages, then developed two alternative adaptive massage control procedures based on the sensor's estimate, and verified the effectiveness of the results through testing the subjects. We observed that in course A (dynamic comfortableness) the peripheral skin temperature dropped and the GSR and pulse rate increased, while in course B (static comfortableness) the peripheral skin temperature rose and the GSR and pulse rate dropped. By the end of the control sequence, there was a statistically significant difference in the amounts of change in both the peripheral skin temperature and the GSR between the two sequences (p < 0.05). To examine the effects of each course more closely, we mapped the trajectories of physiological change during the control sequences of each course at twentysecond intervals, and the results correlated closely with the subjective assessments. These results suggest that bio-control adapted to comfortableness is feasible.