• Title/Summary/Keyword: biomedical application

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Contrast Enhancement of Laser Speckle Contrast Image in Deep Vasculature by Reduction of Tissue Scattering

  • Son, Taeyoon;Lee, Jonghwan;Jung, Byungjo
    • Journal of the Optical Society of Korea
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    • v.17 no.1
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    • pp.86-90
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    • 2013

  • Various methods have been proposed for enhancing the contrast of laser speckle contrast image (LSCI) in subcutaneous blood flow measurements. However, the LSCI still suffers from low image contrast due to tissue turbidity. Herein, a physicochemical tissue optical clearing (PCTOC) method was employed to enhance the contrast of LSCI. Ex vivo and in vivo experiments were performed with porcine skin samples and male ICR mice, respectively. The ex vivo LSCIs were obtained before and 90 min after the application of the PCTOC and in vivo LSCIs were obtained for 60 min after the application of the PCTOC. In order to obtain the skin recovery images, saline was applied for 30 min after the application of the PCTOC was completed. The visible appearance of the tubing under ex vivo samples and the in vivo vasculature gradually enhanced over time. The LSCI increased as a function of time after the application of the PCTOC in both ex vivo and in vivo experiments, and properly recovered to initial conditions after the application of saline in the in vivo experiment. The LSCI combined with the PCTOC was greatly enhanced even in deep vasculature. It is expected that similar results will be obtained in in vivo human studies.

  • https://doi.org/10.3807/JOSK.2013.17.1.086 인용 PDF KSCI

The Development of a New Polymer Valve for Artificial Blood Pumps (인공심장 및 심실보조장치용 고분자 인조판막의 개발)

  • Suh, S.W.;Wetering, J.E.v.d.;Park, Y.J.;Park, S.K.;Kim, I.Y.;Min, B.G.
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.11
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    • pp.104-106
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    • 1993

  • Some cardio-vascular assist systems need more inexpensive artificial heart valves for short-term use. To meet with this need, we have developed a new polymer valve that is very simple to manufacture and of which its dimensions are easy to change, depending on its application. We have tested the hydrodynamic performance of the new polymer valve using a mock circulatory testing system and studied the flow through the valve using high-speed camera combined with image processing techniques. The results show that this valve is superior in its performances to the other valves (Bjork-Shiley mechanical valve and trileaflet polymer valve) and have no stagnation points. We also have tested the hemolytic potential of the valve. The valve is less hemolytic than the Bjork-shiley mechanical valve finally, we have applied this valve to a left ventricular assist device that we are developing.

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SPECT Image Analysis Using Computational ROC Curve Based on Threshold Setup

  • Kim, Moo-Sub;Shin, Han-Back;Kim, Sunmi;Shim, Jae Goo;Yoon, Do-Kun;Suh, Tae Suk
    • Progress in Medical Physics
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    • v.28 no.3
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    • pp.77-82
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    • 2017

  • We proposed the objective ROC analysis method based on the setting of threshold value for evaluation of single photon emission computed tomography (SPECT) image. This proposed ROC analysis method uses the quantification computational threshold value to each signal on the SPECT image. The SPECT images for this study were acquired by using Monte Carlo n-particle extended simulation code (MCNPX, Ver. 2.6.0, Los Alamos National Laboratory, USA). The basic SPECT detectors and specific water phantom were realized in the simulation, and we could get the simulation results by the simulation operation. We tried to analyze the reconstructed images using threshold value application based objective ROC method. We can get the accuracy information of reconstructed region in the image. This proposed ROC technique can be helpful when we have to evaluate the weak signal for the NM image. In this study, the proposed threshold value based computational ROC analysis method can provide better objectivity than the conventional ROC analysis method.

  • https://doi.org/10.14316/pmp.2017.28.3.77 인용 PDF

Development of an Improved Endotoxin Detection Method Using Centrifugation (원심분리법을 이용한 혈청 내 내독소의 개선된 측정방법 연구)

  • Choi, Hyeong Jwa;Lim, Yoo Jung;Lee, Eun Hee;Park, Jin Yeon;Prabagar, Miglena G.;Park, Hyung Soon;Kang, Young Sun
    • Microbiology and Biotechnology Letters
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    • v.41 no.2
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    • pp.242-248
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    • 2013

  • Endotoxins are part of the outer membrane of the cell wall of gram-negative bacteria and are continuously released during bacterial growth. Endotoxins typically induce severe sepsis and septic shock, which cause more than 50% of mortalities. Endotoxins are easily measured in the serum by the limulus amebocyte lysate (LAL) test. However, a nonspecific result is obtained, because the high concentration of serum proteins disturbs the enzyme reaction of the LAL test. In order to solve this problem, the LAL test was performed in this study after the centrifugation of the boiled serum samples to remove the impurities. As a result, among the various conditions examined, endotoxin measurement with the LAL test was the most accurate and repeatable after centrifugation of the boiled serum at $100^{\circ}C$. Moreover, the endotoxin was accurately and repeatedly measured from the prepared sera of mice that had been administered an intraperitoneal injection of purified lipopolysaccharides (LPS) or E. coli. Therefore, the application of centrifugation to remove impurities from boiled serum gives an accurate measurement of endotoxins in the sera of normal subjects or patients, and this will lead to the improved diagnosis and prevention of diseases caused by endotoxins. In addition, the centrifugation of boiled serum samples should be considered and included in the development of endotoxin test kits.

  • https://doi.org/10.4014/kjmb.1301.01010 인용 PDF KSCI