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A laser-induced breakdown spectroscopy (LIBS) system using a microchip laser for plasma generation is proposed for in-situ analysis of trace minerals in human hair. The LIBS system is more compact and less expensive than conventional LIBS systems, which use flashlamp-excited Q-switched Nd:YAG lasers. Focusing optics were optimized using a Galilean beam expander to compensate for the low emitted pulse energy of the microchip laser. Additionally, hundreds of generated LIBS spectra were accumulated to improve the signal-to-noise ratio of the measurement system, and argon gas was injected at the irradiation point to enhance plasma intensity. LIBS spectra of human hair in the UV to near IR regions were investigated. Relative mass concentrations of Ca, Mg, and Zn were analyzed in hairs obtained from five subjects using the intensity of C as a reference. The results coincide well with those measured via inductively coupled argon plasma mass spectrometry. The lowest detectable concentrations of the measured LIBS spectra were 9.0 ppm for Mg, 27 ppm for Zn, and 710 ppm for Ca. From these results, we find that the proposed LIBS system based on a microchip laser is feasible for the analysis of trace minerals in human hair.
Makoto Nakagawa; Yuji Matsuura. Analysis of Trace Metals in Human Hair by Laser-Induced Breakdown Spectroscopy with a Compact Microchip Laser. Sensors 2021, 21, 3752 .
AMA StyleMakoto Nakagawa, Yuji Matsuura. Analysis of Trace Metals in Human Hair by Laser-Induced Breakdown Spectroscopy with a Compact Microchip Laser. Sensors. 2021; 21 (11):3752.
Chicago/Turabian StyleMakoto Nakagawa; Yuji Matsuura. 2021. "Analysis of Trace Metals in Human Hair by Laser-Induced Breakdown Spectroscopy with a Compact Microchip Laser." Sensors 21, no. 11: 3752.
Human breath is a biomarker of body fat metabolism and can be used to diagnose various diseases, such as diabetes. As such, in this paper, a vacuum ultraviolet (VUV) spectroscopy system is proposed to measure the acetone in exhaled human breath. A strong absorption acetone peak at 195 nm is detected using a simple system consisting of a deuterium lamp source, a hollow-core fiber gas cell, and a fiber-coupled compact spectrometer corresponding to the VUV region. The hollow-core fiber functions both as a long-path and an extremely small-volume gas cell; it enables us to sensitively measure the trace components of exhaled breath. For breath analysis, we apply multiple regression analysis using the absorption spectra of oxygen, water, and acetone standard gas as explanatory variables to quantitate the concentration of acetone in breath. Based on human breath, we apply the standard addition method to obtain the measurement accuracy. The results suggest that the standard deviation is 0.074 ppm for healthy human breath with an acetone concentration of around 0.8 ppm and a precision of 0.026 ppm. We also monitor body fat burn based on breath acetone and confirm that breath acetone increases after exercise because it is a volatile byproduct of lipolysis.
Yudai Kudo; Saiko Kino; Yuji Matsuura. Vacuum Ultraviolet Absorption Spectroscopy Analysis of Breath Acetone Using a Hollow Optical Fiber Gas Cell. Sensors 2021, 21, 478 .
AMA StyleYudai Kudo, Saiko Kino, Yuji Matsuura. Vacuum Ultraviolet Absorption Spectroscopy Analysis of Breath Acetone Using a Hollow Optical Fiber Gas Cell. Sensors. 2021; 21 (2):478.
Chicago/Turabian StyleYudai Kudo; Saiko Kino; Yuji Matsuura. 2021. "Vacuum Ultraviolet Absorption Spectroscopy Analysis of Breath Acetone Using a Hollow Optical Fiber Gas Cell." Sensors 21, no. 2: 478.
A mid-infrared spectroscopic system using a high-speed wavelength-swept and pulsed quantum cascade laser (QCL) for healthcare applications such as blood glucose measurement is proposed. We developed an attenuated total reflection measurement system comprising the QCL with a micro-electromechanical system (MEMS)-scanning grating, hollow optical fibers, and InAsSb detector and tested its feasibility for healthcare applications. A continuous spectrum was obtained by integrating comb-shaped spectra, the timing of which was slightly shifted. As this method does not require complex calculations, absorption spectra are obtained in real-time. We found that the signal-to-noise ratio of the obtained spectrum had been improved by increasing the number of spectra that were integrated into the spectrum calculation. Accordingly, we succeeded in measuring the absorption spectrum of a 0.1% aqueous glucose solution. Furthermore, the absorption spectra of human lips were measured, and it was shown that estimation of blood glucose levels were possible using a model equation derived using a partial least squares regression analysis of the measured absorption spectra. The spectroscopic system based on the QCL with MEMS-scanning grating has the advantages of compactness and low cost over conventional Fourier transform infrared-based systems and common spectroscopic systems with a tunable QCL that has a relatively large, movable grating.
Takuya Koyama; Naoto Shibata; Saiko Kino; Atsushi Sugiyama; Naota Akikusa; Yuji Matsuura. A Compact Mid-Infrared Spectroscopy System for Healthcare Applications Based on a Wavelength-Swept, Pulsed Quantum Cascade Laser. Sensors 2020, 20, 3438 .
AMA StyleTakuya Koyama, Naoto Shibata, Saiko Kino, Atsushi Sugiyama, Naota Akikusa, Yuji Matsuura. A Compact Mid-Infrared Spectroscopy System for Healthcare Applications Based on a Wavelength-Swept, Pulsed Quantum Cascade Laser. Sensors. 2020; 20 (12):3438.
Chicago/Turabian StyleTakuya Koyama; Naoto Shibata; Saiko Kino; Atsushi Sugiyama; Naota Akikusa; Yuji Matsuura. 2020. "A Compact Mid-Infrared Spectroscopy System for Healthcare Applications Based on a Wavelength-Swept, Pulsed Quantum Cascade Laser." Sensors 20, no. 12: 3438.
Noninvasive, glucose-monitoring technologies using infrared spectroscopy that have been studied typically require a calibration process that involves blood collection, which renders the methods somewhat invasive. We develop a truly noninvasive, glucose-monitoring technique using mid-infrared spectroscopy that does not require blood collection for calibration by applying domain adaptation (DA) using deep neural networks to train a model that associates blood glucose concentration with mid-infrared spectral data without requiring a training dataset labeled with invasive blood sample measurements. For realizing DA, the distribution of unlabeled spectral data for calibration is considered through adversarial update during training networks for regression to blood glucose concentration. This calibration improved the correlation coefficient between the true blood glucose concentrations and predicted blood glucose concentrations from 0.38 to 0.47. The result indicates that this calibration technique improves prediction accuracy for mid-infrared glucose measurements without any invasively acquired data.
Ryosuke Kasahara; Saiko Kino; Shunsuke Soyama; Yuji Matsuura. Unsupervised calibration for noninvasive glucose-monitoring devices using mid-infrared spectroscopy. Journal of Innovative Optical Health Sciences 2018, 11, 1 .
AMA StyleRyosuke Kasahara, Saiko Kino, Shunsuke Soyama, Yuji Matsuura. Unsupervised calibration for noninvasive glucose-monitoring devices using mid-infrared spectroscopy. Journal of Innovative Optical Health Sciences. 2018; 11 (6):1.
Chicago/Turabian StyleRyosuke Kasahara; Saiko Kino; Shunsuke Soyama; Yuji Matsuura. 2018. "Unsupervised calibration for noninvasive glucose-monitoring devices using mid-infrared spectroscopy." Journal of Innovative Optical Health Sciences 11, no. 6: 1.
中赤外領域で発振する量子カスケードレーザー(QCL)を用いた血糖値測定法について紹介する.複数の単一波長QCLと中空光ファイバを用いた中赤外分光システムを構築し,ヒト口唇の吸収スペクトルを測定することにより,血糖値測定を行う.測定に用いるQCLの波長については,フーリエ赤外分光器を用いて行った口唇の吸収スペクトルにおいて,血糖値との高い相関が得られているグルコースの環状構造に起因する吸収ピーク波長1,152 cm−1を選択した.また,グルコースの吸収が現れない1,186 cm−1の吸光度をリファレンスとすることで,ベースラインの変動を取り除くことを試みた.これら2波長における吸光度の差分値と,採血による血糖値を比較したところ,両者の間に相関を確認することができた.
Kiriko Yoshioka; Takuya Koyama; Saiko Kino; Yuji Matsuura. Non-Invasive Blood Glucose Measurement Using Quantum Cascade Lasers. Nippon Laser Igakkaishi 2018, 39, 105 -110.
AMA StyleKiriko Yoshioka, Takuya Koyama, Saiko Kino, Yuji Matsuura. Non-Invasive Blood Glucose Measurement Using Quantum Cascade Lasers. Nippon Laser Igakkaishi. 2018; 39 (2):105-110.
Chicago/Turabian StyleKiriko Yoshioka; Takuya Koyama; Saiko Kino; Yuji Matsuura. 2018. "Non-Invasive Blood Glucose Measurement Using Quantum Cascade Lasers." Nippon Laser Igakkaishi 39, no. 2: 105-110.
For gas analysis systems based on terahertz time-domain spectroscopy (THz-TDS), relatively complex systems have been proposed to enhance the sensitivity to measure small amounts of gas. This paper proposes a simple system comprising a hollow optical fiber with an inner dielectric layer as a low-volume and long-path gas cell THz-TDS-based gas analysis system. The inner dielectric layer of the fiber not only reduces the transmission loss for THz waves, but also protects the metal layer of the fiber from reactive gases. The proposed dielectric-loaded fiber is fabricated by depositing a metal thin film on a polymer film tube. In a gas analysis experiment conducted using the fiber with a THz-TDS system, separating the absorption peaks of NH3 gas and water vapor initially proved to be difficult, although NH3 gas was successfully detected. However, by improving the frequency resolution via Fourier transform and introducing a longer hollow optical fiber, the two peaks were successfully separated and the system sensitivity improved.
Takashi Katagiri; Takahiro Suzuki; Yuji Matsuura. Time-domain terahertz gas spectroscopy using hollow-optical-fiber gas cell. Optical Engineering 2018, 57, 054104 .
AMA StyleTakashi Katagiri, Takahiro Suzuki, Yuji Matsuura. Time-domain terahertz gas spectroscopy using hollow-optical-fiber gas cell. Optical Engineering. 2018; 57 (5):054104.
Chicago/Turabian StyleTakashi Katagiri; Takahiro Suzuki; Yuji Matsuura. 2018. "Time-domain terahertz gas spectroscopy using hollow-optical-fiber gas cell." Optical Engineering 57, no. 5: 054104.
A method for fabricating robust and thin hollow-core optical fibers that carry mid-infrared light is proposed for use in endoscopic laser applications. The fiber is made of stainless steel tubing, eliminating the risk of scattering small glass fragments inside the body if the fiber breaks. To reduce the inner surface roughness of the tubing, a polymer base layer is formed prior to depositing silver and optical-polymer layers that confine light inside the hollow core. The surface roughness is greatly decreased by re-coating thin polymer base layers. Because of this smooth base layer surface, a uniform optical-polymer film can be formed around the core. As a result, clear interference peaks are observed in both the visible and mid-infrared regions. Transmission losses were also low for the carbon dioxide laser used for medical treatments as well as the visible laser diode used for an aiming beam. Measurements of bending losses for these lasers demonstrate the feasibility of the designed fiber for endoscopic applications.
Katsumasa Iwai; Hiroyuki Takaku; Mitsunobu Miyagi; Yi-Wei Shi; Yuji Matsuura. Fabrication of Shatter-Proof Metal Hollow-Core Optical Fibers for Endoscopic Mid-Infrared Laser Applications. Fibers 2018, 6, 24 .
AMA StyleKatsumasa Iwai, Hiroyuki Takaku, Mitsunobu Miyagi, Yi-Wei Shi, Yuji Matsuura. Fabrication of Shatter-Proof Metal Hollow-Core Optical Fibers for Endoscopic Mid-Infrared Laser Applications. Fibers. 2018; 6 (2):24.
Chicago/Turabian StyleKatsumasa Iwai; Hiroyuki Takaku; Mitsunobu Miyagi; Yi-Wei Shi; Yuji Matsuura. 2018. "Fabrication of Shatter-Proof Metal Hollow-Core Optical Fibers for Endoscopic Mid-Infrared Laser Applications." Fibers 6, no. 2: 24.
In this paper, the feasibility of an optical fiber-based photoacoustic imaging system for detecting caries lesions inside a tooth is examined. Models of hidden caries were prepared using a pigment with an absorption spectrum similar to that of real caries lesions, and the occlusal surface of the model teeth containing the pigment was irradiated with laser pulses with a wavelength of 532 nm. An examination of the frequency spectra of the emitted photoacoustic waves revealed that the spectra from simulated caries lesions included frequency components in the range of 0.5–1.2 MHz that were not seen in the spectra from healthy parts of the teeth. This indicates that hidden caries can be detected via a photoacoustic imaging technique. Accordingly, an imaging system for clinical applications was fabricated. It consists of a bundle of hollow-optical fibers for laser radiation and an acoustic probe that is attached to the tooth surface. Results of ex vivo imaging experiments using model teeth and an extracted tooth with hidden caries lesions show that relatively large caries lesions inside teeth that are not seen in visual inspections can be detected by focusing on the above frequency components of the photoacoustic waves.
Takuya Koyama; Satoko Kakino; Yuji Matsuura. A Feasibility Study of Photoacoustic Detection of Hidden Dental Caries Using a Fiber-Based Imaging System. Applied Sciences 2018, 8, 621 .
AMA StyleTakuya Koyama, Satoko Kakino, Yuji Matsuura. A Feasibility Study of Photoacoustic Detection of Hidden Dental Caries Using a Fiber-Based Imaging System. Applied Sciences. 2018; 8 (4):621.
Chicago/Turabian StyleTakuya Koyama; Satoko Kakino; Yuji Matsuura. 2018. "A Feasibility Study of Photoacoustic Detection of Hidden Dental Caries Using a Fiber-Based Imaging System." Applied Sciences 8, no. 4: 621.
A real-time gas monitoring system based on optical absorption spectroscopy is proposed for localized carbon dioxide (CO2) measurement in respiratory tracts. In this system, a small gas cell is attached to the end of a hollow optical fiber that delivers mid-infrared light with small transmission loss. The diameters of the fiber and the gas cell are smaller than 1.2 mm so that the probe can be inserted into a working channel of common bronchoscopes. The dimensions of the gas cell are designed based on absorption spectra of CO2 standard gases in the 4.2 μm wavelength region, which are measured using a Fourier-transform infrared spectrometer. A miniature gas cell that is comprised of a stainless-steel tube with slots for gas inlet and a micro-mirror is fabricated. A compact probing system with a quantum cascade laser (QCL) light source is built using a gas cell with a hollow optical fiber for monitoring CO2 concentration. Experimental results using human breaths show the feasibility of the system for in-situ measurement of localized CO2 concentration in human airways.
Takashi Katagiri; Kyosuke Shibayama; Takeru Iida; Yuji Matsuura. Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts. Sensors 2018, 18, 995 .
AMA StyleTakashi Katagiri, Kyosuke Shibayama, Takeru Iida, Yuji Matsuura. Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts. Sensors. 2018; 18 (4):995.
Chicago/Turabian StyleTakashi Katagiri; Kyosuke Shibayama; Takeru Iida; Yuji Matsuura. 2018. "Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts." Sensors 18, no. 4: 995.
Photoacoustic imaging system using a bundle of hollow-optical fibers to detect hidden dental caries is proposed. Firstly, we fabricated a hidden caries model with a brown pigment simulating a common color of caries lesion. It was found that high frequency ultrasonic waves are generated from hidden carious part when radiating Nd:YAG laser light with a 532 nm wavelength to occlusal surface of model tooth. We calculated by Fourier transform and found that the waveform from the carious part provides frequency components of approximately from 0.5 to 1.2 MHz. Then a photoacoustic imaging system using a bundle of hollow optical fiber was fabricated for clinical applications. From intensity map of frequency components in 0.5-1.2 MHz, photoacoustic images of hidden caries in the simulated samples were successfully obtained.
Satoko Kakino; Yuji Matsuura; Takuya Koyama. Photoacoustic imaging of hidden dental caries by using a bundle of hollow optical fibers. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 2018, 10488, 1 .
AMA StyleSatoko Kakino, Yuji Matsuura, Takuya Koyama. Photoacoustic imaging of hidden dental caries by using a bundle of hollow optical fibers. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII. 2018; 10488 ():1.
Chicago/Turabian StyleSatoko Kakino; Yuji Matsuura; Takuya Koyama. 2018. "Photoacoustic imaging of hidden dental caries by using a bundle of hollow optical fibers." Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 10488, no. : 1.
For non-invasive blood glucose measurement, a measurement system based on mid-infrared ATR spectroscopy equipped with a combination of a QCL as a light source and a hollow-optical fiber as a beam delivery medium is developed. Firstly the measurement sensitivity of the system is evaluated by using glucose solutions and the result shows a significant correlation between optical absorbance and solution concentration. It is also confirmed that the system has a sensitivity that is enough for blood glucose measurement. Then optical absorption of human lips in the mid-infrared wavelength region is measured using a QCL with a wavenumber of 1080 cm-1 where human tissue exhibits strong absorption of glucose and its metabolites. As a result, the measured absorption follows the change of blood glucose well with a time delay of around 10 minutes and correlation factor between the absorbance and the blood glucose level is 0.42.
Yuji Matsuura; Kiriko Yoshioka; Saiko Kino. Blood glucose measurement with multiple quantum cascade lasers using hollow-optical fiber-based ATR spectroscopy. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 2018, 10488, 1 .
AMA StyleYuji Matsuura, Kiriko Yoshioka, Saiko Kino. Blood glucose measurement with multiple quantum cascade lasers using hollow-optical fiber-based ATR spectroscopy. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII. 2018; 10488 ():1.
Chicago/Turabian StyleYuji Matsuura; Kiriko Yoshioka; Saiko Kino. 2018. "Blood glucose measurement with multiple quantum cascade lasers using hollow-optical fiber-based ATR spectroscopy." Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 10488, no. : 1.
Stainless pipe is used as the supporting tube for the infrared hollow fiber to obtain high durability and strong mechanical strength. In order to reduce roughness of inner surface of stainless tubes which causes the additional transmission loss, an acrylic-silicon resin material is used as a buffer layer to the inner wall of stainless tube for a low-loss characteristic. For the dielectric inner-coating layer, cyclic olefin polymer (COP) is used to lower the transmission loss. The COP layer is formed by using liquid-phase coating method. The hollow fiber with optimized COP inner film thickness for CO2 laser light were fabricated and reasonable transmission loss was demonstrated.
Katsumasa Iwai; Hiroyuki Takaku; Mitsunobu Miyagi; Yi-Wei Shi; Xiao-Song Zhu; Yuji Matsuura. Transmission properties of dielectric-coated hollow optical fibers based on stainless tube. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 2018, 10488, 1048804 .
AMA StyleKatsumasa Iwai, Hiroyuki Takaku, Mitsunobu Miyagi, Yi-Wei Shi, Xiao-Song Zhu, Yuji Matsuura. Transmission properties of dielectric-coated hollow optical fibers based on stainless tube. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII. 2018; 10488 ():1048804.
Chicago/Turabian StyleKatsumasa Iwai; Hiroyuki Takaku; Mitsunobu Miyagi; Yi-Wei Shi; Xiao-Song Zhu; Yuji Matsuura. 2018. "Transmission properties of dielectric-coated hollow optical fibers based on stainless tube." Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 10488, no. : 1048804.
An endoscopic fluorescence imaging system based on fiber speckle illumination is proposed. In this system, a multimode fiber for transmission of excitation laser light and collection of fluorescence is inserted into a conventional flexible endoscope. Since the excitation laser light has random speckle structure, one can detect fluorescence signal corresponding to the irradiation pattern if the sample contains fluorophores. The irradiation pattern can be captured by the endoscope camera when the excitation wavelength is within the sensitivity range of the camera. By performing multiple measurements while changing the irradiation pattern, a fluorescence image is reconstructed by solving a norm minimization problem. The principle of our method was experimentally demonstrated. A 2048 pixels image of quantum dots coated on a frosted glass was successfully reconstructed by 32 measurements. We also confirmed that our method can be applied on biological tissues.
Takashi Katagiri; Shuhei Nakano; Yuji Matsuura. Fluorescence endoscopy using fiber speckle illumination. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 2018, 10488, 1 .
AMA StyleTakashi Katagiri, Shuhei Nakano, Yuji Matsuura. Fluorescence endoscopy using fiber speckle illumination. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII. 2018; 10488 ():1.
Chicago/Turabian StyleTakashi Katagiri; Shuhei Nakano; Yuji Matsuura. 2018. "Fluorescence endoscopy using fiber speckle illumination." Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 10488, no. : 1.
Terahertz gas sensing system based on time-domain spectroscopy (THz-TDS) using a hollow-optical fiber gas cell is proposed. A hollow optical fiber functions as a long-path and low-volume gas cell and loading a dielectric layer on the inside of the fiber reduces the transmission loss and the dielectric layer also protects the metal layer of the fiber from deterioration. In the fabrication process, a polyethylene tube with a thin wall is drawn from a thick preform and a metal layer is formed on the outside of the tube. By using a 34-cm long fiber gas cell, NH3 gas with a concentration of 8.5 % is detected with a good SN ratio. However, the absorption peaks of NH3 and water vapor appeared at around 1.2 THz are not separated. To improve the frequency resolution in Fourier transformation, the time scan width that is decided by the scanning length of linear stage giving a time delay in the probing THz beam is enlarged. As a result, the absorption peaks at around 1.2 THz are successfully separated. In addition, by introducing a longer fiber gas cell of 60-cm length, the measurement sensitivity is improved and an absorption spectrum of NH3 gas with a concentration of 0.5 % is successfully detected.
Yuji Matsuura; Takahiro Suzuki; Takashi Katagiri. Terahertz gas sensing based on time-domain-spectroscopy using a hollow-optical fiber gas cell. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 2018, 10488, 1048808 .
AMA StyleYuji Matsuura, Takahiro Suzuki, Takashi Katagiri. Terahertz gas sensing based on time-domain-spectroscopy using a hollow-optical fiber gas cell. Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII. 2018; 10488 ():1048808.
Chicago/Turabian StyleYuji Matsuura; Takahiro Suzuki; Takashi Katagiri. 2018. "Terahertz gas sensing based on time-domain-spectroscopy using a hollow-optical fiber gas cell." Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 10488, no. : 1048808.
A method for performing noninvasive blood glucose measurements was developed. The method is based on mid-infrared absorption spectroscopy and uses only a few wavenumbers to measure blood glucose levels in vivo unconditionally. We found that the regression of blood glucose levels using only three wavenumbers, which were selected using a series cross-validation technique, realized accuracies comparable to those of cases in which a greater number of wavenumbers are used. In addition, we demonstrated the performance of this model through correlations among different types of data.
Ryosuke Kasahara; Saiko Kino; Shunsuke Soyama; Yuji Matsuura. Noninvasive glucose monitoring using mid-infrared absorption spectroscopy based on a few wavenumbers. Biomedical Optics Express 2017, 9, 289 -302.
AMA StyleRyosuke Kasahara, Saiko Kino, Shunsuke Soyama, Yuji Matsuura. Noninvasive glucose monitoring using mid-infrared absorption spectroscopy based on a few wavenumbers. Biomedical Optics Express. 2017; 9 (1):289-302.
Chicago/Turabian StyleRyosuke Kasahara; Saiko Kino; Shunsuke Soyama; Yuji Matsuura. 2017. "Noninvasive glucose monitoring using mid-infrared absorption spectroscopy based on a few wavenumbers." Biomedical Optics Express 9, no. 1: 289-302.
Takashi Katagiri; Keisuke Yaegashi; Yuji Matsuura. Sensitivity improvement of midinfrared gas sensing system using single-wavelength quantum cascade laser and hollow-waveguide gas cell. Optical Engineering 2017, 56, 1 .
AMA StyleTakashi Katagiri, Keisuke Yaegashi, Yuji Matsuura. Sensitivity improvement of midinfrared gas sensing system using single-wavelength quantum cascade laser and hollow-waveguide gas cell. Optical Engineering. 2017; 56 (8):1.
Chicago/Turabian StyleTakashi Katagiri; Keisuke Yaegashi; Yuji Matsuura. 2017. "Sensitivity improvement of midinfrared gas sensing system using single-wavelength quantum cascade laser and hollow-waveguide gas cell." Optical Engineering 56, no. 8: 1.
Atsushi Seki; Katsumasa Iwai; Takashi Katagiri; Yuji Matsuura. Sensitivity improvement of optical fiber acoustic probe for all-optical photoacoustic imaging system. Applied Physics Express 2017, 10, 1 .
AMA StyleAtsushi Seki, Katsumasa Iwai, Takashi Katagiri, Yuji Matsuura. Sensitivity improvement of optical fiber acoustic probe for all-optical photoacoustic imaging system. Applied Physics Express. 2017; 10 (7):1.
Chicago/Turabian StyleAtsushi Seki; Katsumasa Iwai; Takashi Katagiri; Yuji Matsuura. 2017. "Sensitivity improvement of optical fiber acoustic probe for all-optical photoacoustic imaging system." Applied Physics Express 10, no. 7: 1.
A fluorescence measuring method based on glass multi-capillary for detecting trace amounts of proteins is proposed. It promises enhancement of sensitivity due to effects of the adsorption area expansion and the longitudinal excitation. The sensitivity behavior of this method was investigated by using biotin-streptavidin binding. According to experimental examinations, it was found that the sensitivity was improved by a factor of 70 from common glass wells. We also confirmed our measuring system could detect 1 pg/mL of streptavidin. These results suggest that multi-capillary has a potential as a high-sensitive biosensor. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yasuhira Okuyama; Takashi Katagiri; Yuji Matsuura. Multi-capillary based optical sensors for highly sensitive protein detection. Biomedical Imaging and Sensing Conference 2017, 10251, 102511 .
AMA StyleYasuhira Okuyama, Takashi Katagiri, Yuji Matsuura. Multi-capillary based optical sensors for highly sensitive protein detection. Biomedical Imaging and Sensing Conference. 2017; 10251 ():102511.
Chicago/Turabian StyleYasuhira Okuyama; Takashi Katagiri; Yuji Matsuura. 2017. "Multi-capillary based optical sensors for highly sensitive protein detection." Biomedical Imaging and Sensing Conference 10251, no. : 102511.
Photoacoustic method to detect hidden dental caries is proposed. It was found that high frequency ultrasonic waves are generated from hidden carious part when radiating laser light to occlusal surface of model tooth. By making a map of intensity of these high frequency components, photoacoustic images of hidden caries were successfully obtained. A photoacoustic imaging system using a bundle of hollow optical fiber was fabricated for using clinical application, and clear photoacoustic image of hidden caries was also obtained by this system. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Takuya Koyama; Satoko Kakino; Yuji Matsuura. Photoacoustic imaging of hidden dental caries by using a fiber-based probing system. Biomedical Imaging and Sensing Conference 2017, 10251, 1025119 .
AMA StyleTakuya Koyama, Satoko Kakino, Yuji Matsuura. Photoacoustic imaging of hidden dental caries by using a fiber-based probing system. Biomedical Imaging and Sensing Conference. 2017; 10251 ():1025119.
Chicago/Turabian StyleTakuya Koyama; Satoko Kakino; Yuji Matsuura. 2017. "Photoacoustic imaging of hidden dental caries by using a fiber-based probing system." Biomedical Imaging and Sensing Conference 10251, no. : 1025119.
For non-invasive measurement of blood glucose level, attenuated total reflection (ATR) absorption spectroscopy system using a QCL as a light source was developed. The results of measurement of glucose solutions showed that the system had a sensitivity that was enough for blood glucose measurement. In-vivo measurement using the proposed system based on QCL showed that there was a correlation between absorptions measured with human lips and blood glucose level. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kiriko Yoshioka; Saiko Kino; Yuji Matsuura. Noninvasive measurement of blood glucose level using mid-infrared quantum cascade lasers. Biomedical Imaging and Sensing Conference 2017, 10251, 102511 .
AMA StyleKiriko Yoshioka, Saiko Kino, Yuji Matsuura. Noninvasive measurement of blood glucose level using mid-infrared quantum cascade lasers. Biomedical Imaging and Sensing Conference. 2017; 10251 ():102511.
Chicago/Turabian StyleKiriko Yoshioka; Saiko Kino; Yuji Matsuura. 2017. "Noninvasive measurement of blood glucose level using mid-infrared quantum cascade lasers." Biomedical Imaging and Sensing Conference 10251, no. : 102511.