• 대한가정학회지
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• 제42권1호
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• pp.99-113
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• 2004

To protect farmers from solar radiation and UV, the movable sunshade tent was designed and its protection efficiency was measured in the artificial chamber and outdoors. Sunshade tent and the existing farmer's hat were examined. The results were as followes； Heart rate, total body weight loss and temperature of clothing microclimate on the chest and the back were lower in using sunshade tent than those in wearing existing hat in two experiments. In subjective sensation, subjects answered to feel significantly hotter and more uncomfortable in wearing existing hat in two experiments. Rectal temperature was significantly lower using the sunshade hat in experiment at outdoors(p<0.001).

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.259-261
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• 1995

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 춘계학술대회
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• pp.42-44
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• 1993

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.69-72
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• 1996

A new flow visualization image processing technique was studied. Our approach is based on texture fields and has higher performance than similar methods. We tested our method to flow visualization of Total Artificial Heart.

• Journal of Chest Surgery
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• 제27권6호
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• pp.444-450
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• 1994

From June 1984 to February 1994, cardiac valve replacement was performed in 108 patients. The distribution of patients was ranged from 13 to 64 year-old age[mean 39.48 1.24] and 51 patients were male, 57 patients were female [male:female=1:1.1]. 64 patients had mitral valve replacement, 27 patients underwent aortic valve replacement and 17 patients were performed double[mitral & aortic] valve replacement. Total 125 artificial cardiac valves were used, mechanical valves were 51 valves and tissue valves were 74 valves. The duration of follow-up was 473.41 patient-year[mean 4.79 3.29 patient-year] and the information of follow-up was available for 99 patients[92%]. The actuarial survival rates including the operative mortality was 89.5% & 88.3 at postoperative fourth & ninth year. The probability of freedom from overall valve failure, thromboembolism and bacterial endocarditis were 77.5%, 89.2% and 95.6% at ninth year after cardiac valve replacement.

• Journal of Chest Surgery
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• 제26권3호
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• pp.163-169
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• 1993

This is the result of the annual statistic analysis of thoracic and cardiovascular surgical cases in 1992 Korea. Overall 17, 520 cases of surgery [11, 732 cases of thoracic surgery by 54 institutes / 5, 788 cases of cardiovascular surgery by 48 institutes] were done. 1. Tumor [N=2, 532] : Lung was the most frequently involved organ by tumor [54.9%],and the remainders were mediastinum [16.2%] / esophagus [14.8%] / chest wall [11.7%] / tracheobronchus [1.3%] / pleura [1.1%] in order. Of 1, 082 cases of primary lung cancer surgery,the frequency of cell type was squamous [62.6%] / adeno [21.6%] / small cell [7.1%] / large cell [2.7%]. Of 411 cases of mediastinal tumor surgery,the frequency of cell type was neurogenic [28.8%] / thymoma [27.6%] / teratoma [17.7%] / congenital cystic [17.2%]. Of 376 cases of esophageal tumor surgery,primary cancer were the most [85.4%]. 2. Infection [N=3, 157] : Pleura was the most frequently involved organ [59.0%],and the remainders were lung [31.3%] / chest wall [8.6%] / mediastinum [1.1%] in order. 3. Miscellaneous [N=6, 043] : Lung and pleural disease esp. pneumothorax [85.1%] was the most frequent surgical indication. The remainders were chest wall anomaly [3.4%] / benign esophageal disease [3.4%] / diaphragmatic pathology [2.4%] / myasthenia [1.4%] in order. Of 85 cases of thymectomy for myasthenia gravis,thymoma was noted in 58.8%. 1. Congenital heart disease [N=3, 363] : The ratio of noncyanotic to cyanotic heart disease was 3:1. Of 2, 516 cases of noncyanotic heart disease,the frequency of disease entity was VSD [44.1%] / ASD [26.0%] / PDA [19.4%] / PS [3.3%],and that of 847 cases of cyanotic heart disease was TOF [29.4%] / ECD [15.6%] / TGA [9.7%] / DORV [7.6%]. Overall mortalities were 2.1% in noncyanotic and 12.2% in cyanotic heart surgery. 2. Acquired heart disease [N=1, 929] : Of 1, 422 cases of valvular surgery,single mitral pathology was the most frequent candidate [48.0%],and total 1, 574 prosthetic valves which were mainly mechanical [95.6%] were used. Of 376 cases of coronary surgery,triple vessel was the most [35.9%],and the frequency of bypassing grafts was great saphenous vein [52.9%] / internal mammary artery [44.7%] / artificial vessel [2.4%]. Overall mortalities were 3.4% in valvular and 4.5% in coronary surgery. 3. Pericardium,Cardiac tumor,Arrhythmia,Aortic aneurysm,Assist device,and Pacemaker : There were no specific changes compared to previous survey1]. This nation-wide inquiry will be continued and reported annually by KTCS Society.

• Journal of Animal Science and Technology
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• 제59권1호
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• pp.2.1-2.6
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• 2017

Background: This study aimed to analyze the on heart rate, blood lactate concentration, packed cell volume (PCV) and hemoglobin (Hb) response after conducting exercise in endurance horses. Methods: A total of 20 healthy 3-9-years-old Jeju crossbreed mares ($5.95{\pm}2.24$ year) of age and $312.65{\pm}13.59kg$ of weight) currently participating the endurance competition were used. The field tests selected for the experiment was gallop (approximately 8.3 m/s) along the selected 2.5 km course (a natural forest trail, not artificial road; a closed loop course). The horses were divided into three groups according to their age; 3-4 years of age (G1, $3.29{\pm}0.49$ year), 6-7 years of age (G2, $6.42{\pm}0.53$), and 8-9 years of age (G3, $8.50{\pm}0.55$). The measurements times for the heart rate, blood lactate concentration, PCV, and Hb analysis were conducted before exercise (T0), shortly after exercise (T1), 15 min after exercise (T2), and 30 min after exercise (T3), respectively. Data was analyzed using an analysis of covariance (ANCOVA) for repeated measures with times and groups. Results: The results of the comparison depending on the passage of rest time after exercise suggest that the heart rate and blood lactate concentration of three groups at T2 significantly decreased compared to T1 (p < 0.001). PCV of the G2 and G3 groups were significantly decreased at T2 compared to T1 (p < 0.01). Hb values at G2 (p < 0.01) and G3 (p < 0.001) groups were significantly decreased at T2 as compared to T1. However, heart rate, blood lactate concentration, PCV and Hb level at T1 showed no difference in the comparison of horses from different age groups with the exception of G3 group in terms of heart rate. Conclusion: The physiologic and hematological responses of horses during recovery time after 2,500 m exercise with gallop were no significant difference among the groups. These data are useful as a response evaluation method for training of endurance horses.

• Korean Journal of Radiology
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• 제24권9호
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• pp.890-902
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• 2023

Objective: The clinical impact of artificial intelligence-based computer-aided detection (AI-CAD) beyond diagnostic accuracy remains uncertain. We aimed to investigate the influence of the clinical implementation of AI-CAD for chest radiograph (CR) interpretation in daily practice on the rate of referral for chest computed tomography (CT). Materials and Methods: AI-CAD was implemented in clinical practice at the Seoul National University Hospital. CRs obtained from patients who visited the pulmonology outpatient clinics before (January-December 2019) and after (January-December 2020) implementation were included in this study. After implementation, the referring pulmonologist requested CRs with or without AI-CAD analysis. We conducted multivariable logistic regression analyses to evaluate the associations between using AI-CAD and the following study outcomes: the rate of chest CT referral, defined as request and actual acquisition of chest CT within 30 days after CR acquisition, and the CT referral rates separately for subsequent positive and negative CT results. Multivariable analyses included various covariates such as patient age and sex, time of CR acquisition (before versus after AI-CAD implementation), referring pulmonologist, nature of the CR examination (baseline versus follow-up examination), and radiology reports presence at the time of the pulmonology visit. Results: A total of 28546 CRs from 14565 patients (mean age: 67 years; 7130 males) and 25888 CRs from 12929 patients (mean age: 67 years; 6435 males) before and after AI-CAD implementation were included. The use of AI-CAD was independently associated with increased chest CT referrals (odds ratio [OR], 1.33; P = 0.008) and referrals with subsequent negative chest CT results (OR, 1.46; P = 0.005). Meanwhile, referrals with positive chest CT results were not significantly associated with AI-CAD use (OR, 1.08; P = 0.647). Conclusion: The use of AI-CAD for CR interpretation in pulmonology outpatients was independently associated with an increased frequency of overall referrals for chest CT scans and referrals with subsequent negative results.

• 대한의용생체공학회:의공학회지
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• 제43권3호
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• pp.136-146
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• 2022

In this study, it is intended to provide basic data that can help develop a cardiovascular simulator for performance evaluation of pulse wave detectors by identifying the development status of domestic and overseas cardiovascular simulators. A total of 119 papers were selected by excluding duplicate literature, gray literature, and literature not related to a cardiovascular simulator. Based on the selected literature, the research trend of cardiovascular simulators was analyzed. As a result of analyzing the purpose of the study, most of the simulators were developed to evaluate the hemodynamic properties of artificial hearts and valves. In addition, it was used for simulation evaluation or hemodynamic studies such as pulse wave studies. As a result of analyzing configurations of the simulators, a heart most often consisted of only one left ventricle. For blood vessels, the Windkessel model was most often constructed using chambers and valves. In most studies, blood was reproduced by mixing glycerin and water to reproduce both density and viscosity. In addition, as a result of analysis from the perspective of medical device performance evaluation, simulators for evaluating artificial heart and artificial valves have been studied a lot, whereas simulators for blood pressure, pulse wave, and blood flow devices have been relatively insignificant. Based on the review results, we suggested considerations when developing a simulator for performance evaluations of a pulse wave detector.

• Journal of Chest Surgery
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• 제21권3호
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• pp.479-487
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• 1988

Valve replacements in 82 children, aging up to 15 years[mean 11.67 years] were done at Seoul National University Hospital during 13 years period from 1974 to 1986. The patients were composed of 5] males and 31 females and 50 patients had acquired heart disease and 32 patients congenital heart disease. 75 patients received single valve replacements, 6 patients double valve replacements, 1 patient triple valve replacement, and among all of them, 11 patients redo-replacements. The bioprosthetic valves have been applied to 58 patients and prosthetic valve to 24 patients and the latter was the main artificial valve since 1984. Among the 69 patients who had definite post-operative records, the overall mortality was 27.5%[20.3% was early mortality and 7.2% late mortality] and the overall mortality was lowered to 4.3% since 1984. There were early post-operative complication rate of 26.1% and late complication rate 34.8%, and among the latter, the valve failure rate was 11.4% patient-year, and the thrombo-embolism rate 1.76%/patient-year. 55 patients among the survivals after post-operative 1 month, were received follow-up with various anticoagulating medication for total 2046 patient-months[mini-mum 1 month to maximum 90 month, mean 37.2*25.44 months] and actuarial survival rate was 82*8% at 5 years and valve failure free and thrombo-embolic free survival rate were 61*8% and 90*3% respectively. And among them, valve failure free survival `rate of tissue valve were 91*6% at post-operative 2 years, 78*3% at 3 years, 59*9% at 4 years, 54*10% at 5 years, 53*15% at 6 years, so markedly decreased at 3-5 years post-operatively. These results suggest that cardiac valve replacement in children have been effective therapeutic method though various problems are still remained, and the choice of valve should be prosthetic valve mainly due to its durability at the present.