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

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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

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 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

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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.