• 한국전산유체공학회:학술대회논문집
• /
• 2011.05a
• /
• pp.161-168
• /
• 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
• /
• 2006.12a
• /
• pp.121-124
• /
• 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.

• The Journal of Korean Medicine
• /
• v.35 no.3
• /
• pp.155-165
• /
• 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.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.6
• /
• pp.4031-4039
• /
• 2015

The problems related with blood supply shortage and the stability of blood transfusion are on the rise, as it is expected that the blood doners will decrease but the blood use amount for aged population will increase, owing to low birth and aged population increase. The purpose of this study is to analyze the hospital characteristics which affect patients receiving and non-receiving blood transfusion for the knee and hip total replacement arthroplasty. Data were collected from Health Insurance Review and Assessment Service's 2011 sample data, and 5,370 inpatients were abstracted from them. Logistic regression analysis was performed, using SPSS 20. Independent variables used are hospital characteristics variables and patient characteristics variables. Hospital characteristics variables are hospital type, ownership, residence and the number of usable beds, and patient characteristics variables are gender, age, severity, type of anesthesia, main diagnosis, whether or not of anemia and insurance class. At the result of this study, it was found that hospital type, region, gender, age, severity, main diagnosis and whether or not of anemia were the factors that mostly affected the blood transfusion for knee arthroplasty. And hospital type, residence, gender, age, severity, type of anesthesia and whether of not of anemia were the factors that mostly affected the blood transfusion for hip arthroplasty. In addition to that, it is expected that this research which analyzed the present state of blood transfusion and its influence factors are cost effective, and would make a good use of preliminary data for good quality of medical service.

• Korean Journal of Agricultural Science
• /
• v.46 no.3
• /
• pp.559-567
• /
• 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.

• Journal of Biomedical Engineering Research
• /
• v.18 no.2
• /
• pp.179-186
• /
• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.383-386
• /
• 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
• /
• v.22 no.3
• /
• pp.147-153
• /
• 2015

Purpose: This study was aimed to investigate the contamination rates of blood culture in a neonatal intensive care unit (NICU) and to examine the clinical characteristics related to the contamination. Methods: Eight hundred thirty cases of blood culture performed from March 2013 to February 2014 were analyzed. We evaluated the contamination rates of blood culture by blood sampling sites and compared the clinical characteristics such as real name system and body weights of the contaminated cases and those of non-contaminated ones. The clinical characteristics were retrospectively reviewed by medical records. Results: The overall contamination rate was 3.6% (30/830). The contamination rates by blood sampling sites were as follows: peripheral vein 15.6% (10/64), peripheral artery 2.6% (20/759), and umbilical arterial catheter 0% (0/7). There was no difference in the contamination rates between cases with and without real name system (P=0.484). However, there were significant differences in the contamination rates by the physicians who performed the culture (P=0.038) and body weight (<1,000 g vs. ${\geq}1,000g$) at the time of blood culture (P<0.001). Conclusions: These results suggest that neonates with a body weight less than 1,000 g have more risks of the contamination of blood culture. Furthermore, there is a necessity to provide blood culture performers with active feedbacks and individualized education plans that can help diminish blood culture contamination rates. Prospective studies in a systematic manner that can be applied in actual clinical settings are needed in order to figure out factors that can diminish the contamination rates of blood culture in NICU.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.22 no.1
• /
• pp.76-88
• /
• 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.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.4 s.247
• /
• pp.314-319
• /
• 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.