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 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.