• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.161-168
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• 2011

Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2006년도 추계학술대회 논문집
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• pp.121-124
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• 2006

The arteries are very important in cardiovascular system and easily adapt to varying flow and pressure conditions by enlarging or shrinking to meet the given hemodynamic demands. The blood flow in arteries is dominated by unsteady flow phenomena due to heart beating. In certain circumstances, however, unusual hemodynamic conditions cause an abnormal biological response and often induce circulatory diseases such as atherosclerosis, thrombosis and inflammation. Therefore quantitative analysis of the unsteady pulsatile flow characteristics in the arterial blood vessels plays important roles in diagnosing these circulatory diseases. In order to verify the hemodynamic characteristics, in-vivo measurements of blood flow inside the extraembryonic arterial bifurcation cascade of chicken embryo were carried out using a micro-PIV technique. To analyze the unsteady pulsatile flow temporally, the (low images of RBCs were obtained using a high-speed CMOS camera at 250fps with a spatial resolution of $30{\mu}m\times30{\mu}m$ in the whole blood vessels. In this study, the unusual flow conditions such as flow separation or secondary flow were not observed in the arterial bifurcations. However, the vorticity has large values in the inner side of curvature of vessels. In addition, the mean velocity in the arterial blood vessel was decreased and pulsating frequency obtained by FFT analysis of velocity data extracted in front of the each bifurcation was also decreased as the bifurcation cascaded.

• 대한한의학회지
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• 제35권3호
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• pp.155-165
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• 2014

Objectives: The pulse diagnosis to identify the symptoms has been considered important in Korean medicine. The position and character of disease would be confirmed by pulse diagnosis of left and right radial artery. This paper is to analyze the characteristics and differences of left and right blood vessels. Methods: In this study, left and right radial artery and dorsalis pedis artery was measured and analyzed by using condenser typed pulse analyzer. Commercially available pulse analyzer was used to measure the radial artery. The pulse wave was measured in 20 laboratory healthy men and women. The blood vessel aging degree and index of augmentation of blood vessel was obtained from the measured pulse wave graph and the characteristics and differences of the left and right blood vessel was analyzed. Results: The significant difference of pulse transit time between the right handed and non-right handed was not found. The correlation of radial artery and dorsalis pedis artery had no significant difference. By obtaining the blood vessel aging index (AGI) and augmentation index (AI) of blood vessel at the left and right radial artery, the significant difference between right handed and non-right handed was not found. Conclusions: The result of this study would help to explain the characteristic of blood vessel with respect to the left and right handed. We suggest that research of pulse wave of the left and right blood vessel using pulse analyzer should be needed in further study.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.4031-4039
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• 2015

저출산 고령화로 헌혈인구는 감소하고, 노년층의 혈액사용량은 증가할 것으로 예상되어 혈액부족과 수혈의 안정성 문제가 대두되고 있다. 이에 본 연구에서는 만성 퇴행성관절염인 슬관절과 고관절 전치환술 환자의 수혈에 영향을 주는 요인을 분석하고자 하였다. 이를 위해 건강보험심사평가원의 2011년 환자표본자료 중 입원환자 5,370명을 대상으로 하였으며, SPSS 20 프로그램을 이용하여 로지스틱 회귀분석을 실시하였다. 독립변수로 사용된 변수는 병원특성과 환자특성으로 병원특성은 의료기관 종류, 설립구분, 기관소재지와 가동병상수를, 환자특성으로는 성, 연령, 중증도, 전신마취유무, 주 진단, 빈혈유무와 의료보험종류로 구분하였다. 분석결과, 슬관절전치환술 환자의 수혈에 유의한 영향을 미치는 변수로는 의료기관 종류, 기관소재지, 성, 연령, 중증도, 주 진단, 빈혈유무였으며, 고관절전치환술 환자의 수혈에 유의한 영향을 주는 변수로는 의료기관 종류, 기관소재지, 성, 연령, 중증도, 전신마취유무, 빈혈유무였다. 수혈현황과 영향요인을 분석한 본 연구는 비용 효과적이며, 양질의 의료를 위한 기초자료로 활용될 수 있을 것으로 기대한다.

• 농업과학연구
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• 제46권3호
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• pp.559-567
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• 2019

This experiment was conducted to investigate the effects of pig skin collagen supplementation on growth performance, organ weight, blood characteristics, and intestinal microbiota in broilers. A total of 50 Ross 308 broilers were used for 2 weeks. The five dietary treatments were as follows: NC) basal diet, PC) NC + fish collagen powder 0.1%, T1) NC + pig skin collagen 0.1%, T2) NC + pig skin collagen 0.5%, and T3) NC + pig skin collagen 1.0%. The body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were not affected (p > 0.05) by the dietary treatments in this experiment. Additionally, there were no significant differences (p > 0.05) in the organ weights among the treatments. Broilers fed T1, T2 and T3 diets had higher (p < 0.05) white blood cell (WBC) counts than the broilers fed the NC and PC diets. The Lactobacillus counts in the excreta were improved (p < 0.05) in the broilers fed the T1 and T2 diets. Moreover, the Salmonella counts in the excreta were decreased (p < 0.05) in the broilers fed the PC and T1 diets. In conclusion, supplementation of pig skin collagen in diets improved the white blood cells (WBCs) in the blood and Lactobacillus counts in the excreta, and reduced the Salmonella counts in the excreta. However, when pig skin collagen was increased in the diets, there were no significant differences (p > 0.05). Therefore, the addition of 0.1% pig skin collagen in the feed provided beneficial effects on the blood characteristics and the intestinal microbiota environment.

• 대한의용생체공학회:의공학회지
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• 제18권2호
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• pp.179-186
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• 1997

Steady and physiological flows of a Newtonian fluid and blood in the abdominal gorta/iliac artery bifurcation are numerically simulated to understand the etiology and pathogenesis of atherosclerosis. Distributions of velocity, pressure, and wall shear stress in the bifurcated arterial vessel model are calculated to investigate the differences of flow characteristics between steady and physiological flows and to compare flow characteristics of blood with that of a Newtonian fluid For the given Reynolds number the flow characteristics of physiological flows for a Newtonian fluid and blood in the bifurcated arterial vessel are quite different from thcse of steady flows. No flow separation or flow reversal in the bifurcated region appears downstream of a stenosis during the acceleration phase. However, during the deceleration phase the flow exhibits flow separation in the outer walls of daugtlter branches, which extends to the entire wall region.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.383-386
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• 2007

As the blood flow characteristics have been recognized to be closely related to various cardiovascular diseases, it is very important to predict them accurate enough in an efficient way. Thus, this paper proposes a one-dimensional spectral finite element model for the human blood vessels. The spectral finite element model is formulated in the frequency-domain by using the exact frequency dependent shape functions and applied to an ascending aorta.

• Pediatric Infection and Vaccine
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• 제22권3호
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• pp.147-153
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• 2015

목적: 본 연구는 신생아중환자실에 입원한 환자에서 혈액 배양 오염률을 조사하고, 오염유무에 따른 임상적 특성을 비교하고자 하였다. 방법: 고신대학교복음병원 신생아중환자실에 입원한 환자들을 대상으로 시행한 830건의 혈액 배양 검사 결과에 대해 분석하였다. 혈액 배양 오염률과 채혈부위별 오염률을 조사하였고, 말초혈액 배양 시 오염 유무에 따른 임상적인 특성을 비교하기 위해 의무기록을 조사하였다. 결과: 연구기간 중 오염률은 3.6%였다. 채혈 부위별 오염률은 말초정맥 15.6%, 말초동맥 2.6%, 배꼽동맥 도관 0%였다. 실명제가 시행되지 않았던 기간의 오염률은 2.7% (4/149), 시행 기간에는 4.4% (25/573)로 오염률의 차이가 없었다(P=0.484). 시술자별 오염률은 0-11.1%로 시술자간 차이가 있었다(P=0.038). 채혈 시 몸무게가 1,000 g 미만인 경우 오염률이 유의하게 높았다(P<0.001). 결론: 몸무게가 적은 미숙아에서 혈액 배양 오염률이 더 높을 수 있으므로 채혈 방법에 주의가 필요하며, 오염률이 높은 시술자를 관리해야 한다. 신생아에서 혈액 배양 오염률을 감소시킬 수 있는 인자들을 파악하고 실제 임상에서 적용하기 위한 전향적이고, 체계적인 연구가 필요할 것으로 보인다.

• 한방안이비인후피부과학회지
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• 제22권1호
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• pp.76-88
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• 2009

Back ground and Objective : There is a need for objectification and scientific verification of Pattern identification in Oriental medicine. The purpose of this study was to investigate the skin characteristics of Qi deficiency and Blood deficiency animal models. Material and Methods : Sprague-Dawley rats were divided into three groups: normal group, Qi deficiency group and Blood deficiency group. The Qi deficiency animal model was induced through restriction of food (75g/kg/day) for 20 days. Blood deficiency animal model was induced by bleeding from tail vein(0.3 ml/time) 8 times. The normal animal model was kept without any intervention. The general condition was observed by measuring body weight, body temperature, blood pressure, pulse rate, and hematological and biochemical parameters. The skin characteristics were observed by measuring the erythema index(EI), melanin index(Ml), transepidermal water loss(TEWL) and dermal microcirculation. Results : 1. In the Qi deficiency group, body weight was lower than the other groups. In the Qi deficiency group, blood pressure was lower than in the Normal group. There was no difference in body temperature and pulse rate between the three groups. 2. In the Qi deficiency group, blood sugar was lower than in the Blood deficiency group. There was no difference in triacylglycerol between the three groups. In the Qi deficiency group, the WBC count was lower than in the Blood deficiency group. RBC count was highest in the Qi deficiency group, Normal group and Blood deficiency group respectively. In the Qi deficiency group, Hb and Hct were higher than the other groups. 3. EI and MI were decreased in the Qi deficiency group, and EI showed a significant decrease. 4. EI and MI were increased in the Blood deficiency group, and MI showed a significant increase. 5. TEWL was significantly increased in the Qi deficiency group, while it was decreased in the Blood deficiency group, TEWL was highest in the Qi deficiency group, Normal group and Blood deficiency group respectively and all three groups showed significant difference. 6. In the Qi deficiency group, dermal microcirculation was lower than the other groups. Conclusion : The above results show that the erythema index decreases in the Qi deficiency model, and the melanin index increases in the Blood deficiency model. The Qi deficiency animal model shows an increase in transepidermal water loss, while the Blood deficiency animal model shows a decrease. Further studies should develop new models of Pattern Identification that are more specific.

• 대한기계학회논문집B
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• 제30권4호
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• pp.314-319
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• 2006

To analyze in-vivo blood flow characteristics in a chicken embryo, in-vivo experiment was carried out using micro-PIV technique. Because endothelial cells in blood vessels are subject to shear stress of blood flow, it is important to get velocity field information of the placental blood flow. Instantaneous velocity fields of an extraembryonic blood vessel using a high-speed camera and intravital microscope. The flow images of RBCs were obtained with a spatial resolution of $20\times20{\mu}m$ in the whole blood vessels. The mean velocity field data confirm that the blood flow does show non-Newtonian fluid characteristic. The blood in a branched vessel merged smoothly without any flow separation into the main blood vessel with the presence of a slight bump. This in-vivo micro-PIV measurement technique can be used as a powerful tool in various blood flow researches.