著者

松村 健太 李 知炯 山越 健弘

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.3, pp.120-128, 2016-06-10 (Released:2016-11-23)

参考文献数

43

被引用文献数

2

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The advent of the smartphone, a compact but powerful and multifunctional computing device, permits the measurements of various physiological indices using a commercially available device alone. This is achieved by using built-in flash LED as a light source and built-in CMOS camera as a photo detector, and is called smartphone photoplethysmography (PPG). Although smartphone PPG is so easy that even a non-specialist can operate by oneself in daily life, it should be used with sufficient knowledge of its effectiveness and limitation. Otherwise, users may encounter unpredictable pitfalls. In this review article, we describe the basics of smartphone PPG in terms of the general background of PPG, restrictions especially for smartphone PPG, and caution during measurement, which are essential information for effective daily life measurement.

著者

山越 健弘 李 知炯 松村 健太

出版者

福岡工業大学

雑誌

挑戦的萌芽研究

巻号頁・発行日

2016-04-01

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諸外国では飲酒運転防止装置の実用化が進み,呼気ガス式手法が一般的になってきたが,様々な問題点がある.そこで,光電容積脈波を利用し,血中成分の吸光特性から指尖部の入射光に対して散乱された光を検出する方法に着目した.しかし,アルコール固有の吸収帯域は水への吸収度が高い近赤外長波長帯域の905 nm,1185 nm,および1690 nmに存在し,人間の身体のほとんどが水分であり,検出される光が極めて微弱で,動作や外部環境に敏感でノイズが多く,これを如何に低減できるかの実験検討をまず行い,次いで人を対象とした飲酒負荷実験を行った結果,光電容積脈波にて血中アルコール濃度が予測可能であることが示唆された。

著者

李 知炯 小柳 貴寛 松尾 勇輝 草場 志帆里 福本 悠斗 山越 健弘

出版者

福岡工業大学情報科学研究所

雑誌

福岡工業大学情報科学研究所所報 = Reports of Computer Science Laboratory (ISSN:13446169)

巻号頁・発行日

no.28, pp.19-24, 2017-10-31

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We compared the pulse rate (PR) derived from the ear photoplethysmogram (PPG) using a green light with the heart rate (HR) derived from the electrocardiogram (ECG) as a reference. In 20 young healthy participants (21.7 ± 2.7 S.D. years), simultaneous measurements of the ECG (chest lead II), peak green light (525 nm) PPG, and peak near-infrared light (810 nm) PPG from the two sites of the ear (tragus and helix-crus) and index fingertip, respectively, were made. We used a treadmill for walking task, at speeds of 0, 2, 4 and 6 km/h. The results showed that the PR derived from the green light PPG from the ear significantly related to HR derived from ECG (tragus: r = 0.984, helix-crus: r = 0.972, respectively). In addition, the limit of agreement (± 1.96 S.D.) in Bland-Altman plots between PR and HR were ± 5.960 bpm and ± 7.944 bpm. In conclusion, these findings suggest that green light ear PPG could be the basis of a suitable, practical, method for monitoring PR in normal daily life.

著者

草場 志帆里 李 知炯 甲斐 智希 福本 悠斗 山越 健弘

出版者

福岡工業大学総合研究機構

雑誌

福岡工業大学総合研究機構研究所所報

巻号頁・発行日

no.1, pp.97-102, 2018-12

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The aim of this study is to compare the heart rate (HR) derived from electrocardiogram (ECG) with the pulse rate (PR) derivedfrom the green light ear photo-plethysmogram (PPG) using an earphone. We developed a compact device that the PPG sensorcomprising a green LED and phototransistor was embedded in the earphone. The weight of device was 8.8 g. In 10 subjects,simultaneous measurements of ECG, and green light (525 nm) PPG from the front of tragus were made at the following treadmillspeeds: 0, 2, 4, 6, 8 km/h. During walking (2, 4 km/h), the results showed that the PR derived from the green light PPG from theear significantly related to HR derived from ECG (r = 0.98). In addition, the limit of agreement in Bland-Altman plots betweenthese indices were ± 3.95 (1.96 SD) bpm. In conclusion, these findings suggest that the green light ear PPG using earphone mightbe practical measurement for monitoring HR during walking.

著者

山越 健弘 山越 康弘 松村 健太 廣瀬 元

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.2, pp.154-165, 2009-04-10 (Released:2009-09-09)

参考文献数

37

---

Physiological monitoring was carried out during the motor sport of Racing Kart driving. In addition to highlighting the importance of physiological measurement during motor sports, this study may have social relevance through its potential to contribute to decreasing automobile accidents in overload situations by using appropriate biosignals. The measurement quantities collected in this study were instantaneous heart rate, HR, vector magnitude of acceleration, G, blood pressure, BP, and core body temperature, Teardrum. After giving informed consent 11 healthy male subjects (34.4 ± 7.7 S.D. yrs) were tested in the racing circuit. We successfully monitored the physiological variables during karting, finding a statistically significant decrease in BP (p < 0.01) and a rise in Teardrum (p < 0.01) immediately after the driving period. In addition, we have confirmed that HR was maintained at approximately 150bpm, which, by means of time-frequency analysis, could be explained by sympathetic acceleration. Furthermore, it is strongly suggested that the rise in HR could be closely related to the G forces to which the drivers were subjected. These results clearly disclose to us one aspect of the possible physiological responses and the importance of physiological monitoring during motor sports.

著者

田中 志信 本井 幸介 野川 雅道 山越 健弘 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.3, pp.467-474, 2006 (Released:2008-05-01)

参考文献数

18

被引用文献数

1

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The daily monitoring of health conditions at home is a very important subject not only as an effective scheme for the early diagnosis and treatment of cardiovascular and other diseases, but also for the prevention and control of such diseases. From this point of view, we have been developing a fully automated “non-conscious” monitoring system for home healthcare. In this paper, we describe the structural details of a newly developed blood pressure (BP) measurement system built into a toilet seat and some results obtained using the system. The principle used for BP measurement was the volume-oscillometric method. A reflectance-type photoplethysmographic sensor was installed in an appropriate position on the toilet seat, and it was automatically lifted and lowered using a newly designed helicoid-type actuator. Systolic (SBP) and mean BP (MBP) were obtained using the arterial volume pulsation signal obtained by the sensor. In order to evaluate the accuracy of the BP measurements, simultaneous measurements were carried out using two types of commercially available BP monitors (upper arm and wrist). Simultaneous measurement using an “invasive technique” via catheterization to the right brachial artery was also conducted. From the results obtained (bias[s.d.] for SBP; Upper arm: -1.20 [7.90] mmHg, Wrist: 0.44 [7.28] mmHg, Invasive: -0.41 [4.91] mmHg, bias [s.d.] for MBP; Upper arm: 4.40 [6.91] mmHg, Wrist: 5.07 [8.04] mmHg, Invasive: 3.68 [5.69] mmHg), reasonable accuracy of the present system was clearly demonstrated. This system, which requires no cumbersome procedures for BP measurement such as cuff setting, proper positioning of measuring site and so on, appears to be a useful means for long-term home healthcare monitoring.

著者

山越 健弘 小川 充洋 松村 健太 板坂 優希 宮崎 慎平 山越 康弘 ROLFE Peter 廣瀬 元 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.50, no.2, pp.237-247, 2012-04-10 (Released:2012-07-13)

参考文献数

40

被引用文献数

1

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In this preliminary study, we examined in human volunteers the performance of the developed prototype device for non-invasive quantification of blood alcohol concentration (BAC) by near-infrared light which is highly transparent to the body. We aimed at applying the results to the final goal of developing a novel alcohol-based vehicle ignition-interlock device. Accumulating evidence shows that one of the ethyl alcohol absorption peaks in the near-infrared region is present at 1,185 nm. We combined this with our recent development of a non-invasive optical method for blood glucose measurement, which we call pulse glucometry, using blood volume pulsations in a finger within a cardiac cycle. Thus, we developed a novel method, pulse alcometry, for non-invasive measurement of BAC. We calculated second derivative values of optical density (ODλ”) to remove baseline over a band including three wavelengths, 1,150 nm, 1,185 nm, and 1,220 nm. Then, a simple linear regression analysis was performed with the measured ODλ” to predict BAC levels. In 3 healthy male volunteers, during alcohol intake and washout, periodic optical measurements using the present device were made simultaneously with collection of blood samples for in vitro BAC analysis. In leave-one-out cross validations within an individual, the measured BAC and the predicted BAC correlated well (r = 0.773∼0.846, mean absolute error = 0.134∼0.333mg/ml). We conclude that, from the results of this preliminary study, the new method appears to be able to estimate BAC levels non-invasively. However, further investigations in a larger group of subjects will be needed in order to determine fully the operational performance of this new measurement system.

著者

山越 健弘 山越 康弘 松村 健太 廣瀬 元

出版者

日本生体医工学会 = the Japanese Society for Medical and Biological Engineering

雑誌

Transactions of Japanese Society for Medical and Biological Engineering = 生体医工学 (ISSN:18814379)

巻号頁・発行日

vol.47, no.2, pp.154-165, 2009-01-01

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金沢大学大学院自然科学研究科

著者

山越 康弘 小川 充洋 山越 健弘 田村 俊世 山越 憲一

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.46, no.1, pp.49-57, 2008-02-10

参考文献数

27

被引用文献数

3

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金沢大学大学院自然科学研究科An optical method recently proposed for non-invasive in vivo blood glucose concentration (BGL) measurement, named "Pulse Glucometry", was combined and compared with four multivariate analyses for constructing calibration models: Principal Component Regression (PCR), Partial Least Squares Regression (PLS), Artificial Neural Network (ANN), Support Vector Machines Regression (SVMsR). A very fast spectrophotometer for "Pulse Glucometry" provides the total transmitted radiation spectrum (I_λ) and the cardiac-related pulsatile component (ΔI_λ) superimposed on I_λ in human fingertips over a wavelength range from 900 to 1700 nm with resolution of 8 nm in 100 Hz sampling. From a family of I_λs measured, which include information relating to blood constituent such as BGL values, differential optical densities (ΔOD_λs, where ΔOD_λ=Log(1+ΔI_λ/I_λ)) were obtained and normalized by the ΔOD_λ values at 1100 nm. Finally, the 2nd derivatives of the normalized ΔOD_λs(Δ^2OD_λs) along wavelengths were calculated as regressors. Subsequently, calibration models from paired data sets of regressors(the values of Δ^2OD_λs) and regressand (the corresponding known BGL values) were constructed with PCR, PLS, ANN and SVMsR. The results show that each calibration model provides a relatively good regression with a modified 5-fold cross validation for total 95 paired data, in which the BGLs ranged from 100.7-246.3 mg/dl. The results were evaluated by the Clarke error grid analysis and all data points obtained from all calibration models fell within the clinically acceptable regions (region A or B). Among them, ANN and SVMsR calibration provided the best plot distributions (in ANN; Region A: 77 plots (81.1%), B: 18 plots (18.9%). in SVMsR; Region A: 78 (82.1%), B: 17 (17.9%)). Total calculation time of SVMsR is about 100 times shorter than ANN. These results suggest that a calibration model using SVMsR is highly promising for "Pulse Glucometry.

著者

山越 健弘 山越 憲一 松村 健太

出版者

金沢大学

雑誌

挑戦的萌芽研究

巻号頁・発行日

2011

---

光電容積信号を用いた容積振動法に基づき,血圧,脈圧,心拍数,血管緊張度,および血管弾性度の5生理指標を,指一本から同時かつ簡便に取得可能なプロトタイプを開発した。そしてこの動作性能評価を行い,次いで上記5指標から体調の善し悪しを判別可能かどうかのパイロット・スタディを行った。また,飲酒運転防止を目的とし,光電容積信号を利用した血中アルコール濃度計測の可能性をin vitro(アルコール吸光特性試験)及びin vivo(飲酒負荷試験)下で予備検討した。

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

田中 志信 本井 幸介 野川 雅道 山越 健弘 山越 憲一

出版者

日本生体医工学会

雑誌

生体医工学 : 日本エム・イー学会誌 = Transactions of the Japanese Society for Medical and Biological Engineering : BME (ISSN:1347443X)

巻号頁・発行日

vol.44, no.3, pp.467-474, 2006-09-10

被引用文献数

3

---

The daily monitoring of health conditions at home is a very important subject not only as an effective scheme for the early diagnosis and treatment of cardiovascular and other diseases, but also for the prevention and control of such diseases. From this point of view, we have been developing a fully automated "non-conscious" monitoring system for home healthcare. In this paper, we describe the structural details of a newly developed blood pressure (BP) measurement system built into a toilet seat and some results obtained using the system. The principle used for BP measurement was the volume-oscillometric method. A reflectance-type photop-lethysmographic sensor was installed in an appropriate position on the toilet seat, and it was automatically lifted and lowered using a newly designed helicoid-type actuator. Systolic (SBP) and mean BP (MBP) were obtained using the arterial volume pulsation signal obtained by the sensor. In order to evaluate the accuracy of the BP measurements, simultaneous measurements were carried out using two types of commercially available BP monitors (upper arm and wrist). Simultaneous measurement using an "invasive technique" via catheterization to the right brachial artery was also conducted. From the results obtained (bias [s.d.] for SBP; Upper arm: -1.20 [7.90] mmHg, Wrist: 0.44 [7.28] mmHg, Invasive: -0.41 [4.91] mmHg, bias [s.d.] for MBP; Upper arm: 4.40 [6.91] mmHg, Wrist: 5.07 [8.04] mmHg, Invasive: 3.68 [5.69] mmHg), reasonable accuracy of the present system was clearly demonstrated. This system, which requires no cumbersome procedures for BP measurement such as cuff setting, proper positioning of measuring site and so on, appears to be a useful means for long-term home healthcare monitoring.