Noninvasive optical system for real-time concentration measurement in optical active solution

Dept. of Biomedical Engineering/석사[한글]광 측정 방식은 비침습적 측정방식으로, 의학 및 생물학 분야에서 그 응용이 증가하고 있다. 현재 주로 응용되고 있는 농도 측정 방식은 일반적으로 샘플을 밖으로 추출 후, 분석기를 통한 오프라인 검출 방식과 배양기 내부에 전극형 측정장치를 장착하여 측정하는 온라인 검출 방식이 응용되고 있다. 오프라인 측정 방식의 경우, 과도한 수작업에 의한 사용자 측정 에러, 샘플채취과정에서의 감염위험, 보정을 위한 표준시약의 필요성과 같은 단점이 있고, 온라인 측정 방식의 경우, 고가 및 안정성 그리고 반응기 내부 조건에 따른 오차 발생들의 단점이 야기되고 있다. 편광계 측정방식(Polarimetry)은 샘플에 비 침습적인 광 측정 방식으로, 빛의 투과광량 변화로부터 샘플의 농도를 검출할 수 있다. 본 연구에서는 편광계 측정방식을 응용, 비침습적이며 온라인 측정이 가능한 광학 시스템에 대하여 논하고자 한다. 특히 기존의 측정방식에 비해, 배양액의 별도의 샘플 없이, 직접 응용이 가능한 것을 특징으로 하며, 또한 편광 측정방식에 있어서, 광 경로의 가변을 통한 측정감도 향상이 가능한 것을 특징으로 한다. [영문]Over the last two decades, optical polarimetry method has been applied for concentration monitoring as a non-invasive alternative method. Commercial polarimeter is widely used to measure the concentration of chemical compounds with optical activity. However, the current device is based on off-line measurement method which involves sample extraction process to measure the concentration. The process does not reflect the real-time status of accurate sample concentration. Moreover, sample contamination may occur during the sample extraction process. In polarimetry method, the sensitivity of measurement can be controlled by varying optical path length. However, in current polarimeter, the sample cell should be exchanged to vary the optical path length. The process requires a considerable amount of time and may cause sample contamination problem. Therefore, it is necessary to develop a new polarimetry system which can measure exact concentrations without performing sample extraction in real-time. In this study, we introduced a new polarimetry probe system which may be utilized effectively to monitor concentration of solution. The new system was designed to have variable optical path lengths to control the optical rotation angle of polarized light. The system and feasibility of concentration meter have been described in the following articles.ope

An Implementation

Maste

Characterizationof defects in SIMOX SOI substrate

Docto

근골력계 질병에 대한 최소침습적 레이저 치료 시스템의 효능 평가

Dept. of Biomedical Engineering/박사Although the mechanism of low-level laser therapy (LLLT) is still unclear, there has been recent interest in using it to treat orthopedic diseases. Numerous studies have developed optical clearing methods to increase the therapeutic efficacy of LLLT because, owing to light scattering and absorption, light energy decreases when penetrating tissue.In this study, we investigated methods that enhance the therapeutic efficacy of LLLT. First, we evaluated the effects of individual and combination applications of two optical clearing methods: hyperosmotic chemical agents (HCAs) and compression. The results showed that the transmitted light energy increased when the methods were combined compared to individual applications. However, the inherent light energy loss problem of LLLT was still present. Therefore, we developed the minimally invasive laser needle system (MILNS) to address the inherent light energy loss problem during tissue penetration and applied it to three orthopedic diseases: osteoporosis, arthritis, and muscle atrophy. MILNS employs a fine hollow needle that delivers light to targets in deep tissue without light scattering. The therapeutic efficacy of MILNS was evaluated by micro computed tomography (μ-CT) and histological analysis. The bio-stimulatory effects of MILNS on orthopedic diseases were found to produce positive therapeutic outcomes such as the suppression of bone loss, arthritis, and muscle atrophy progression. Thus, MILNS improved the therapeutic efficacy of LLLT because the three orthopedic diseases had controversial results with regard to the bio-stimulation of LLLT.Although we realized positive therapeutic outcomes, the therapeutic parameters of MILNS have to be investigated because the response of each biological cell to the wavelength and light dosage differed. Based on the results of this study, we expect that MILNS may be developed as a treatment modality that enhances the therapeutic efficacy of LLLT.ope

Cz 실리콘에서 발생하는 Thermal donor의 전기적 thermal donors in CZ silicon

Maste

I-V modeling for nanoscale n-MOSFET from liquid-nitrogen temperature to room temperature

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70nm CMOS BSIM4 Macro modeling for RFIC design

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