• 대한화학회지
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• 제54권5호
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• pp.497-499
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• 2010

• 대한의용생체공학회:의공학회지
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• 제37권1호
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• pp.53-60
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• 2016

Monitoring of dermal collagen is important to assess various scar conditions, and many diagnostic methods have been applied to quantify collagen contents in scar tissue. In this study, Monte Carlo simulation was used to evaluate diffuse reflectance distributions in scar condition by a near-infrared laser source. The results showed that the effective distance of the light source and the detector was 2 mm to monitor the various scar conditions using diffuse reflectance spectroscopy. This study may suggest to the optimal design for a near infrared diffuse reflectance spectroscopy during the scar treatment.

• 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 $SpO_2$.

• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.721-722
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• 2007

• 대기
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• 제14권2호
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• pp.11-22
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• 2004

A technique on atmospheric correction algorithm to the multi-band reflectance of Landsat TM imagery has been developed using an atmospheric radiation transfer model for eliminating the atmospheric and surface diffusion effects. Despite the fact that the technique of satellite image processing has been continually developed, there is still a difference between the radiance value registered by satellite borne detector and the true value registered at the ground surface. Such difference is caused by atmospheric attenuations of radiance energy transfer process which is mostly associated with the presence of aerosol particles in atmospheric suspension and surface irradiance characteristics. The atmospheric reflectance depend on atmospheric optical depth and aerosol concentration, and closely related to geographical and environmental surface characteristics. Therefore, when the effects of surface diffuse and aerosol reflectance are eliminated from the satellite image, it is actually corrected from atmospheric optical conditions. The objective of this study is to develop an algorithm for making atmospheric correction in satellite image. The study is processed with the correction function which is developed for eliminating the effects of atmospheric path scattering and surface adjacent pixel spectral reflectance within an atmospheric radiation model. The diffused radiance of adjacent pixel in the image obtained from accounting the average reflectance in the $7{\times}7$ neighbourhood pixels and using the land cover classification. The atmospheric correction functions are provided by a radiation transfer model of LOWTRAN 7 based on the actual atmospheric soundings over the Korean atmospheric complexity. The model produce the upward radiances of satellite spectral image for a given surface reflectance and aerosol optical thickness.

• 대한화학회지
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• 제44권4호
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• pp.316-321
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• 2000

분광분석장치의 구성성분들인 광원과 광 검출기를 cell을 중심으로 은쪽에배열하여 제작한 반사분광분석장치를 제작하였으며, 이러한 분사분광분석장치가 액체시료에 대한 흡수분광분석에 사용될 수 있는지를 알아보았다. 이를 위해 $Cu^{2+}$이온의 표준용액들을 대상으로 반사분광분석장치와 기존의 흡수분광분석장치를 대표하는'Spectronic 20' 성능을 비교한 결과, $1.0{\times}10^{-4}$M~$1.00{\times}10^{-1}$M 농도 범위에서 반사분석장치는 'Spectronic 20'에 비해 더 높은 감도를 나타내었다.

• Journal of Biosystems Engineering
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• 제17권4호
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• pp.370-381
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• 1992

Optical properties of fruits can provide information for nondestructive quality evaluation. An attempt is made here to develop an optical method for quality evaluation of apple using the spectral reflectance of its surface. Optical fiber was used to transmit light conveniently from light source to sample and sample to detector. Spectral reflectances of two types of Fuji variety-one of which was exposed to the sunlight directly (non-bagging) and the other was wrapped with bag (bagging) - were investigated from the wavelength ranging of 400nm to 700nm. The relationships between reflectance characteristics and quality indices such as chlorophyll content, anthocyanin content, and soluble solids were analyzed.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.420-423
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• 1997

The oxygen saturation of blood can be measured by sensing the difference absorption in optical spectra of Hb and $HbO_2$, as the well known previous study. [1] In this study we developed the noninvasive tissue reflectance oximeter(TRO) using three kinds of LEDs which produce a peak spectral emission at a wavelength of 565, 660 and 940nm. And we tested the unction of the TR oximeter by comparing the output signals measured on normal tissue to measured on low oxygenated tissue. The results showed that oxygen saturation of blood and biological tissue can be monitored from the separation arrangement light source and detector.

• 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.

• 대한의용생체공학회:의공학회지
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• 제15권1호
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• pp.35-40
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• 1994

생체조직의 계층성과 광양자속의 경로간의 관계를 연구하기 위하여 어레이형의 프로부를 설계하였다. S-D간격이 변함에 따라서 광원의 파장이 다르면 광은 서로 다른 경로를 가지며, 최대 리플렉턴스의 위치도 달랐다. 설계된 프로브로 측정된 최대 리플렉턴스시의 S-D간격은 7.5mm, 청색은 2.5mm 이었으며 광이 조직내를 투과 및 반사될 때 조직에 따라 주 경로가 있으며, S-D 간격을 변화시키면서 리플렉턴스를 측정하므로서 조직의 계층성을 평가할 수 있었다.