• 한국정밀공학회지
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• 제12권7호
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• pp.46-52
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• 1995

This paper proposes methodologies for the development of radiation thermometer using InSb photo-detector of which spectral sensitivity is excellent over the wave length range of 2 .mu. m .approx. 5 .mu. m. The proposed radiation thermometer has broad measurement range from normal to high, up to more than 1000 .deg. C, with high accuracy, and can measure temperature on the material surface or heat emission noncontactely with high speed. Optical system was consisted of two convex lens with foruslength of 15.2mm for infrared lay focusing, Ge filter to cut the short wave length components and sapphire filter to cut the long wave length components. The cold shielded was installed in the whole surface of the light-absorbing element to remove the error- mometer, calibration using black body furnace which has temperature range of 90 .deg. C .approx. 1100 .deg. C was carried out, and temperature calaibration curve was obtained by exponential function curvefitting. The result shows maximum error less than 0.24%(640K .+-. 1.6K) over the measurement range of 90 .deg. C .approx. 700 .deg. C, and from this result the usefulness of the developed thermometer has been confirmed.

• Journal of Welding and Joining
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• 제20권1호
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• pp.62-68
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• 2002

This study investigated the feasibility of penetration depth measurement using infrared temperature sensing on the weld surface. The detection point was optimized by FEM analysis in the laser keyhole welding. The profile of the weld surface temperature was measured using infrared detector array. Surface temperature behind the weld pool is proportional or exponentially proportional to penetration depth and bead width. From the results, the monitoring device of surface temperature using infrared detector array was applicable fur real time penetration depth control.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3844-3853
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• 2023

Although radiation and chemotherapy methods for cancer therapy have advanced significantly, surgical resection is still recommended for most cancers. Therefore, intraoperative imaging studies have emerged as a surgical tool for identifying tumor margins. Intraoperative imaging has been examined using conventional imaging devices, such as optical near-infrared probes, gamma probes, and ultrasound devices. However, each modality has its limitations, such as depth penetration and spatial resolution. To overcome these limitations, hybrid imaging modalities and tracer studies are being developed. In a previous study, a multi-modal laparoscope with silicon photo-multiplier (SiPM)-based gamma detection acquired a 1 s interval gamma image. However, improvements in the near-infrared fluorophore (NIRF) signal intensity and gamma image central defects are needed to further evaluate the usefulness of multi-modal systems. In this study, an attempt was made to change the NIRF image acquisition method and the SiPM-based gamma detector to improve the source detection ability and reduce the image acquisition time. The performance of the multi-modal system using a complementary metal oxide semiconductor and modified SiPM gamma detector was evaluated in a phantom test. In future studies, a multi-modal system will be further optimized for pilot preclinical studies.

• 한국군사과학기술학회지
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• 제1권1호
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• pp.227-237
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• 1998

HgCdTe Is the most versatile material for the developing infrared devices. Not like III-V compound semiconductors or silicon-based photo-detecting materials, HgCdTe has unique characteristics such as adjustable bandgap, very high electron mobility, and large difference between electron and hole mobilities. Many research groups have been interested in this material since early 70's, but mainly due to its thermodynamic difficulties for preparing materials, no single growth technique is appreciated as a standard growth technique in this research field. Solid state recrystallization(SSR), travelling heater method(THM), and Bridgman growth are major techniques used to grow bulk HgCdTe material. Materials with high quality and purity can be grown using these bulk growth techniques, however, due to the large separation between solidus and liquidus line on the phase diagram, it is very difficult to grow large materials with minimun defects. Various epitaxial growth techniques were adopted to get large area HgCdTe and among them liquid phase epitaxy(LPE), metal organic chemical vapor deposition(MOCVD), and molecular beam epitaxy(MBE) are most frequently used techniques. There are also various types of photo-detectors utilizing HgCdTe materials, and photovoltaic and photoconductive devices are most interested types of detectors up to these days. For the larger may detectors, photovoltaic devices have some advantages over power-requiring photoconductive devices. In this paper we reported the main results on the HgCdTe growing and characterization including LPE and MOCVD, device fabrication and its characteristics such as single element and linear array($8{\times}1$ PC, $128{\times}1$ PV and 4120{\times}1$ PC). Also we included the results of the dewar manufacturing, assembling, and optical and environmental test of the detectors.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.578-579
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• 2015

Transmission and reflectance are two non-invasive techniques to perform pulse oximetry. This paper presents a design of reflectance-based pulse oximetry for watch-type wearable device, in which sensor and detector are located on the same surface of the body part. The basic principle of a pulse oximeter is based on the measurement of the red and infrared (IR) light absorption. Oxygenated blood has significant differences of light absorption characteristics than deoxygenated blood under red (660 nm) and infrared (940 nm) wavelength. Infrared is absorbed more by oxygenated hemoglobin than red. So the hardware implementation is included placing of the two LEDs (red and IR) with single photo-detector in the middle on the patient's wrist to get the corresponding pulsatile signals which are used to estimate the $SpO_2$.

• 한국기계가공학회지
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• 제9권4호
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• pp.53-58
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• 2010

In this paper, the output characteristics of PSD(Position Sensetive Detector) used in measurement system are described. Most of the precision measurment systems are accomplished by a laser diode(LD), a photo diode(PD) and PSD(Position Sensetive Detector), which are used in reflection of mirror or projection of infrared spectrometer. But it is especially restricted by resolution of PD and PSD in nano-measurement. A new inclined light methods into the PSD are employed in the surface measurement system for increasing the resolution. As the results, we can know that the output characteristics of detective senser (PSD) become more than 2 or 3 times by changing inclined angle(range: 5 degree) compared with common angle. In addition, the experiment results are confirmed that the change of inclined angle is not affecting to the linearity and repeating.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.203-224
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• 2003

In recent years, a miniature spectrometer has been extensively developed due to the combination of fiber optics and semiconductor detector arrays. This type of miniature spectrometer has advantages of low price and robustness because of the capability of mass production and no moving parts are required such as lenses, mirrors and scanning monochromator. In this study, for skin diagnostics, a portable near infrared (NIR) system has been developed using a LlGA microspectrometer, which is photo-diode arrays-type.(omitted)

• 약학회지
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• 제46권5호
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• pp.331-336
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• 2002

The purpose of this study is to develop a non-invasive blood glucose measurement method by a portable near infrared (NIR) system which was newly integrated by our lab. The portable NIR system includes a tungsten halogen lamp, a specialized reflectance fiber optic probe and a photo diode array type InGaAs detector; which was developed by a microchip technology based on the lithography. Reflectance NIR spectra of different parts of human body (finger tip, earlobe, and inner lip) were recorded by using a fiber optic probe. The spectra were collected over the spectral range 1100 ∼ 1740 nm. Partial least squares regression (PLSR) was applied for the calibration and validation for the determination of blood glucose. The calibration model from earlobe spectra presented better results, showing good correlation with a glucose oxidase method which is a mostly used standard method. This model predicted the glucose concentration for validation set with a SEP of 33 mg/dL. This study indicated the feasibility for non-invasive monitoring of blood glucose by a portable near infrared system.

• 분석과학
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• 제16권2호
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• pp.95-101
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• 2003

본 연구에서는 근적외선 분광분석법 (NIR)을 이용하여 메탄올과 에탄올 혼합액 중의 물의 함량을 비파괴적으로 측정하였다. Photo-diode array 방식의 휴대용 NIR system과 scanning 방식의 NIR spectrometer를 이용하여 두 기기 사이의 calibration 결과를 비교하였다. 알코올 혼합액 중의 물의 함량을 정량분석 하기 위해 부분최소자승회귀분석법 (PLSR : partial least squares regression)을 사용하였다. 그 결과 SEP (standard error of prediction)가 photo-diode array 방식을 사용하였을 때는 0.10%, scanning 방식을 사용하였을 때는 0.12%였다. Calibration 모델의 안정성을 확인하기 위하여 6일 동안 2%의 메탄올을 함유하고 있는 에탄올 용액 중의 물의 함량이 3%, 5% 및 7% 되도록 시료를 조제하여 측정하였다. 두 가지 방식의 NIR 모두 3%이내의 변동계수 (CV : coefficient of variation)로 좋은 결과를 나타내었다. 이번 연구를 통해서 메탄올과 에탄올 혼합액 중의 물의 함량 측정이 근적외선 분광분석법을 이용하여 성공적으로 수행되었고 photo-diode array 방식의 휴대용 NIR 시스템을 이용해서 scanning 방식의 NIR spectrometer를 이용한 결과와 유사한 결과를 얻을 수 있었다.

• 약학회지
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• 제47권3호
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• pp.148-153
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• 2003

Skin moisture is an important factor in skin health. Measurement of moisture content can provide diagnostic information on the condition of skin. In this study, a portable near-infrared (NIR) system was newly integrated with a photo diode array detector that has no moving parts, and this system has been successfully applied for the evaluation of human skin moisture. Diffuse reflectance spectra were collected and transformed to absorbance using 1 nm step size over the wavelength range of 1100 nm to 2200 nm. Partial least squares regression (PLSR) was applied to develop a calibration model. For practical use for the evaluation of human skin moisture, the PLS model for human skin moisture was developed in vivo using the portable NIR system on the basis of the relative water content values of stratum corneum from the conventional capacitance method. The PLS model showed a good correlation. The calibration with the use of PLS model predicted human moisture with a standard error of prediction (SEP) of 3.5 at 1120∼1730 nm range. This study showed the possibility of skin moisture measurement using portable NIR system.