• Biomolecules & Therapeutics
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• 제16권3호
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• pp.249-254
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• 2008

The present study was undertaken to determine whether hypoxia influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Hypoxia significantly inhibited fluoride-induced contraction regardless of endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction suggesting that other pathway such as $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, hypoxia significantly decreased fluoride-induced increase of phospho-myosin-targeting subunit of myosin light chain phosphatase (pMYPT1). Interestingly, hypoxia didn't inhibit significantly phenylephrine-induced contraction suggesting that myosin light chain kinase (MLCK) activity or thin filament regulation is less important on the hypoxia-induced vasorelaxation in the denuded muscle than Rho-kinase activity. In conclusion, this study provides the evidence and possible related mechanism concerning the vasodilation effect of hypoxia on the agonist-specific contraction in rat aortic rings regardless of endothelial function.

• 한국정보통신학회논문지
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• 제15권7호
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• pp.1591-1597
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• 2011

본 논문에서는 심폐기능에 이상이 있는 중환자의 상태를 진단하거나 치료 방향을 정하기 위하여 심박 출량을 측정하는 플랫폼 구현에 관한 연구로써, 센서가 내장된 Swan-Ganz Catheter를 체내에 삽입 후, 생리식염수를 투입하여 생기는 온도변화량을 열희석법을 이용하여 심박출량을 구하는 방법을 사용한다. Swan-Ganz Catheter는 온도센서와 압력센서를 포함하고 있으며 이를 통해 입력되는 센서 값을 보다 세밀하게 수집한다면 심박출량, 전선 및 폐혈관저항, 산소소모량 등을 보다 정확하게 계산해 낼 수가 있으므로 환자의 상태를 보다 정확하게 진단 및 치료가 가능하게 한다.

• 전기학회논문지
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• 제64권2호
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• pp.304-309
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• 2015

Applicable range of Photoplethysmography (PPG) becomes wider as a non-invasive physiological measurement technique. However, PPG waveform is easy to be distorted by ambient light or vascular variation from temperature changes. Especially, irregular variation of PPG waveform caused by ambient temperature not only severely distorts the PPG, but also leads miss interpretation in clinical applications. Therefore, the investigation of between temperature and PPG waveform is quite important in using PPG. The purpose of this research is to quantify the PPG waveform characteristic and to investigate the waveform variation following the temperature change on measuring site. To quantify the fluctuation of PPG waveform, we use two techniques; detrended fluctuation analysis (DFA) and AC/DC analysis of PPG. We record PPG under temperature stress, which applied by medical use heat pack ($40^{\circ}C$) and ice pack ($0^{\circ}C$). Ten participants were applied to the experiment, and the result was evaluated to approve the temperature effect with statistical method, Wilcoxon signed rank test. The result shows that the AC component (p<0.05) and perfusion index DFS scale exponent (p<0.01) of PPG have the significance to temperature stress except for a DC component of PPG.

• 비파괴검사학회지
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• 제33권3호
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• pp.283-288
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• 2013

This paper describes development of a high speed Doppler OFDI system for non-invasive vascular imaging. Doppler OFDI (optical frequency domain imaging) is one of the phase-resolved second generation OCT (optical coherence tomography) techniques for high resolution imaging of moving elements in biological tissues. To achieve a phase-resolved imaging, two temporally separated measurements are required. In a conventional Doppler OCT, a pair of massively oversampled successive A-lines is used to minimize de-correlation noise at the expense of significant imaging speed reduction. To minimize a de-correlation noise between targeted two measurements without suffering from significant imaging speed reduction, several methods have been developed such as an optimized scanning pattern and polarization multiplexed dual beam scanning. This research represent novel imaging technique using frequency multiplexed dual beam illumination to measure exactly same position with aimed time interval. Developed system has been verified using a tissue phantom and mouse vessel imaging.

• 대한의용생체공학회:의공학회지
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• 제13권2호
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• pp.165-174
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• 1992

Compliance mismatch across an end-to-end anastomosis was measured In the In vitro experimental setup. A 35mm camera was used and Image process was done in Gould/ DeAnza Image processor. The results showed that compliances of Penrose tubing and synthetic PTFE grafts were In good agreement with the previously reported In vivo data. PTFE grafts exhibited a nonlinear behavior with compliance decreasing with Increasing transmural pressure, whereas the compliance of the Penrose tubing remained relatively constant within the range of the pressures in which data were obtained. The lumen cross sections at the anastomosis were affected by the suture and the mismatch In compliance between the Penrose tubing and vascular grafts. The varla~lons In the lumen dtameter at the anastomosis was more pronounced with increasing transmural pressures. From the present study, it was clearly demonstrated that the compliance of prosthetic grafts Is much lower than that of the arteries. In addition to the hemodynamlc consequences, compliance mismatch across the anastomosis has been known to lead to Increased anastomotlc and suture stresses with resultant suture line dehlscence and false aneurysm formation. Thus, there are good hemodynamic reasons to suppose that Introduction of a less compliant arterial graft Into the arterial circulation wlll be damaging and that grafts should be made to match the elastic behavior of their host arteries as closely possible.

• 대한의용생체공학회:의공학회지
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• 제13권3호
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• pp.189-194
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• 1992

As people's income and intake of animal fat rapidly increase, so does choresterol concentration in blood. Thus diseases such as non-insulin-dependent diabetes mellitus(NIDDM)myocardial infraction, high blood pressure, cerebral stroke resulting from atherosclerosis rapidly increase recently. It is very difficult to diagnose atherosclerosis early since its progress is so slow and there is no sypmtoms in the beginning of the disease. In this study a mechanical characteristic, compliance, of the lower leg arteries was measured noninvasively. Changes of blood volume and pressure were measured using impedance plethysmgraphy and mercury sphygmomanometer, respectively. The compliance was calculated by dividing the change of blood volume by the change of pulse pressure ( systolic-diastolic pressure ) . Subjects were 24 asymptomatic persons ranging (rom 30 Ic 58yeras and 14 diabetics from 41 to 59years. The compliances, mean, and systolic pressures were statistically analyzed using a t-test be- tween the healthy and diabetic groups. The average compliance of the healthy and diabetic group was measured 2.79 and 1.82U1/mmHg/cm, respectively and these were significantly different(p<0.01). It was also found that the compliance is a better parameter in differentiating the vascular disease than mean or systolic blood pressure.

• Biomolecules & Therapeutics
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• 제20권3호
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• pp.352-356
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• 2012

The present study was undertaken to determine whether ethanol influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Ethanol significantly inhibited thromboxane $A_2$ mimetic-induced contraction with intact endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction irrespective of endothelium suggesting that the pathway such as Rho-kinase activation, $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, ethanol didn't decrease thromboxane $A_2$ mimetic-induced increase of phospho-myosin phosphatase targeting subunit protein 1 (pMYPT1) or pERK1/2. Interestingly, ethanol didn't inhibit significantly phorbol ester-induced contraction in denuded muscles suggesting that thin filament regulation is less important on the ethanol-induced regulation in the muscle than endothelial NO synthesis. In conclusion, this study provides the evidence and possible related mechanism concerning the effect of ethanol on the agonist-dependent contraction in rat aortic rings with regard to endothelial function.

• 웰빙융합연구
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• 제4권1호
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• pp.27-34
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• 2021

Purpose: The number of people with disabilities and the elderly over 65 years of age is gradually increasing due to physical disabilities and social aging. Their typical physical disorders or chronic diseases include low back pain, sciatic pain, arthritis, and musculoskeletal systems such as discs. The average prevalence of disease is 78%. These are various physical obstacles and hindrances in daily life. Research design, data and methodology: From August 6, 2019 to September 24, 2019, the Senior Welfare Center in Gyeyang-gu, Incheon, operated a healthy body exercise and health education program for living health management. Results: The vascular health index using U-Bio pulse wave was relatively good at the first average of +7.4, but the second average of -6.3. This can be seen as a result of the combination of diet and lifestyle education along with the effect of corrective exercise. As a result of body shape measurement analysis, the number of persons requiring management with 3 or more body imbalances was found to be from 75% before to 62.5% afterwards. Conclusions: Exercise effect appears when exercise lasts for at least 10 weeks. Some performances were good, but there were limitations due to the operation of a short training period.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.69-69
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• 2023

Safflower seeds, classified as a member of the Asteraceae family, a dicotyledonous plant, contain linoleic acid as a major component, known for its pharmacological effect of strengthening bones. Additionally, safflower seeds have been reported to have pharmacological effects on vascular diseases such as atherosclerosis. In this study, we investigated the anti-obesity effect of safflower seed extract by examining its impact on adipocyte differentiation using Oil Red O staining, triglyceride quantification, and GPDH activity measurement. The results showed that safflower seed extract significantly inhibited adipocyte differentiation. Furthermore, we confirmed that safflower seed extract improved body weight, liver weight, adipose tissue size, glucose, and triglyceride levels in a high-fat diet-induced mouse model. These findings suggest that safflower seed extract exhibits potent anti-obesity activity both in vitro and in vivo and has the potential to be developed as a material for future anti-obesity therapies.

• 로봇학회논문지
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• 제19권2호
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• pp.221-228
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• 2024

As the importance of cardiovascular health is highlighted, research on its correlation with blood pressure, the most important indicator, is being actively conducted. Therefore, extensive clinical data is essential, but the measurement of the central arterial blood pressure waveform must be performed invasively within the artery, so the quantity and quality are limited. This study suggested a mock circulatory robot and artificial aorta to reproduce the blood pressure waveform generated by the overlap of forward and reflected waves. The artificial aorta was fabricated with biomimetic silicone to mimic the physiological structure and vascular stiffness of the human. A pressurizing chamber was implemented to prevent distortion of the blood pressure waveform due to the strain-softening of biomimetic silicone. The reproduced central arterial blood pressure waveforms have similar magnitude, shape, and propagation characteristics to humans. In addition, changes in blood pressure waveform due to aging were also reproduced by replacing an artificial aorta with various stiffness. It can be expanded to construct a biosignal database and health sensor testing platform, a core technology for cardiovascular health-related research.