• Journal of Chest Surgery
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• v.36 no.12
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• pp.911-920
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• 2003

In this study, we analyzed the long-term surgical outcome of partial atrioventricular septal defects during the past 17 years at Seoul National University Hospital. Material and Method: A retrospective analysis on mortality, survival, and reoperation and their risk factors was done in 93 patients who underwent surgical correction of partial atrioventricular septal defects between April 1986 and December 2002. 32 patients were male and 61 were female with a median age of 68 months (3∼818 months) and a mean follow-up period of 108 months (1∼200 months). Result: There were 4 operative deaths (4.3%) and one mortality during the follow-up period. 3, 5, 10, and 15 year actuarial survival rates were 95.7%, 94.3%, 94,3%, and 94.3%, respectively. After the surgical correction, left atrioventricular valve Incompetence was improved in 61patients (67.7%), remained same as the preoperative status in 14 patients (15.1%), and was aggravated in 12 patients (12.9%). Reoperation was performed in 8 patients (9.0%) after a mean interval of 38.6 months (3∼136 months). Freedom from reoperation rates at 3, 5, 10, and 15 years after surgical correction were 94.0%, 91.4%, 91.4%, and 88,2%, respectively Reasons for reoperation were 7 left atrioventricular valve incompetence, 2 left ventricular outflow tract obstruction, a residual atrial septal defect, a left atrioventricular valve stenosis, and a right ventricular failure. Left ventricular outflow tract obstruction was the only statistically significant factor. In ten patients, significant arrhythmia was developed and three of them were supraventricular arrhythmia. Complete atrioventricular block occurred in 7 patients and permanent pacemakers were implanted in six of them. Conclusion: Surgical corrections of partial atrioventricular septal defects were performed with low operative mortality. Since left atrioventricular valve incompetence was the most common cause of reoperation and left ventricular outflow tract obstruction was the only risk factor for reoperation, a precise estimation of the left atrioventricular valve morphology and the structure of left ventricular outflow tract are needed. Although left ventricular outflow tract obstruction rarely developed, reoperation was frequently required and resection of subaortic tissue could be peformed but the possibility of recurrence was high, so modified Konno operation could be performed with satisfactory results. Complete atrioventricular block developed frequently in early periods, but was overcome with a precise anatomical understanding of conduction system and experience.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.769-777
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• 2020

The purpose of this study was to investigate the effects of 8 weeks Self-Myofascial Release exercise on body composition, vascular and metabolic functions in obese female college students. The subjects were 19 obese female college students (n = 9) who were randomly assigned to an exercise group(n=9) and control group(n=9), with an exception of except 1 abandonment. The Self-Myofascial Release exercise group performed exercises twice a week for 8 weeks and for 40 minutes at one time using a foam roller, and the control group maintained normal life pattern for the same period. Body composition was measured by body weight, body fat percentage, vascular function was measured by pulse wave velocity(PWV), augmentation index(AIx), brachial artery vascular flow-mediated dilation(FMD), and metabolic function was measured by fasting glucose and triglyceride levels. The Self-Myofascial Release exercise with foam roller showed no significant effect on body weight and body fat percentage. The Self-Myofascial Release exercise with foam roller showed no significant effect on heart rate, FMD, PWV but, SBP, CSBP and AIx were significant decreased. The Self-Myofascial Release exercise with foam roller showed no significant effect on fasting glucose and triglyceride levels. In conclusion, 8-week Self-Myofascial Release exercise for obese female college students showed no significant effect on body composition and metabolic function, but improved SBP, CSBP and AIx levels significantly. Therefore, Self-Myofascial Release exercise will be an effective way to improve the vascular function of obese female college students.

• Journal of Chest Surgery
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• v.31 no.11
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• pp.1056-1062
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• 1998

Background: We prospectively investigated types, incidences, and risk factors for arrhythmias after open heart surgery in adults. Materials and methods: From June 1994 to May 1995, we performed 302 cases of adult cardiac surgery at our department. This study group consisted of 150 men and 152 women, with a mean age of 43.9±28.0(range 16 to 75)years. We included all the patients irrespective of their operative types or disease entities. Results: The overall incidence of arrhythmias after open heart surgery in adults was 58.3%. The incidence of postoperative arrhythmias for redo-valvular heart surgery was 77.8%, and those for simple valvular procedure, coronary artery bypass surgery, aortic surgery, and congenital heart disease were 70.8%, 45.3%, 40.0%, and 29.5%, respectively. Eight out of twelve risk factors showed statistical significance for the development of postoperative arrhythmias. They were preoperative history of arrhythmias, antiarrhythmic drug medication, previous cardiac surgery, larger left ventricular end-diastolic, end-systolic dimension, left atrial dimension on preoperative echocardiogram, longer cardiopulmonary bypass time and aortic cross clamping time. Univariated analyses for age and types of cardioplegic solution did not show statistical significance. Conclusions: Prospective study on postoperative arrhythmias occurrence, treatment and prevention of is warrauted to draw more clear conclusion.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.426-433
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• 2009

Background: Remarkable progress has recently been made in achieving successful early repair of congenital heart disease with using cardiopulmonary bypass in the neonatal period. The aim of this study is to evaluate our short-term outcomes for performing neonatal cardiac surgery under extracorporeal circulation. Material and Method: Fifty five neonates underwent open heart surgery from February 2002 to December 2007. The mean ages and body weight was 13.5 days. and 3.2 kg, respectively. The diagnoses of the patients were transposition of the great arteries (14), total anomalous pulmonary venous connection (7), large ventricular septal defect (VSD) (7), coarotation of the aorta with VSD (6), interrupted aortic arch (5) and others (16). Result: Six patients had difficulties being weaned from extracorporeal circulation. Four patients left the operating room with an open sternum. Low cardiac output syndrome and acute renal insufficiency were observed in 3 patients each, respectively. Post-operative complications were observed in 27 patients (49.1%). The postoperative mortality was 12.7% (7 patients); 5 patients experienced early hospital death and 2 experienced late death (2). Conclusion: In our hospital, early surgical repair with extracorporeal circulation in neonates was feasible with tolerable mortality. Further follow-up required to establish the long-term survival and complications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.1-6
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• 2019

As mobile technologies such as Internet of Things (IoT)-based smart homes and financial technologies (FinTech) are developed, authentication by smart devices is used everywhere. As a result, presence-based biometric authentication using smart devices has become a new mainstream in knowledge-based authentication methods like the existing passwords. The electrocardiogram (ECG) is less prone to forgery, and high-level personal identification is its unique feature from among various biometric authentication methods, such as the pulse, fingerprints, the face, and the iris. Biometric authentication using an ECG is receiving a great deal of attention due to its uses in healthcare and FinTech. In this study, we implemented an ECG authentication system that allows users to easily measure and authenticate their ECG waveforms using a miniaturized wearable device, rather than a large and expensive measurement device. The implemented ECG authentication system identifies ECG features through P-Q-R-S-T feature point identification, and was user-certified under the proposed authentication protocols. Finally, assessment of measurements in a majority of adult males showed a relatively low false acceptance rate of 1.73%, and a low false rejection rate of 4.14%, in a stable normal state. In a high-activity state, the false acceptance rate was 13.72%, and the false rejection rate was 21.68%. In a high-heart rate state, the false acceptance rate was 10.48%, and the false rejection rate was 11.21%.

• Sleep Medicine and Psychophysiology
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• v.19 no.1
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• pp.27-34
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• 2012

Objectives: The analysis of heart rate variability (HRV) is a useful non-invasive tool to investigate the autonomic nerve function. Previous studies on the relationship between HRV and depression have been reported controversial results. Similarly, the correlation between the serum lipids and depression is debatable. The purpose of this study is to examine the relationship between heart rate variability, lipid profile and depression. Methods: A total of 42 patients with major depressive disorder (MDD) and 32 age and sex-matched normal subjects who had no previous history of major medical and mental illnesses were recruited for this study. A structured-interview was used to assess the general characteristics and psychiatric illness. HRV measures were assessed by time-domain and frequency-domain analyses. Psychological symptoms were measured using the Hamilton rating scale for anxiety (HAM-A), Hamilton rating scale for depression (HAM-D). In addition, the evaluation for lipid profile was performed by blood test. Results: In serum lipid profile test, MDD group showed higher cholesterol ($197.68{\pm}42.94$ mg/dL vs. $176.85{\pm}34.68$ mg/dL, p=0.044), TG ($139.45{\pm}92.54$ mg/dL vs. $91.4{\pm}65.68$ mg/dL, p=0.018), LDL ($130.03{\pm}33.18$ vs. $106.62{\pm}27.08$, p=0.004) level than normal control group. In HRV time domain analyses, the standard deviation of the NN interval (SDNN) was decreased in MDD group than normal control group, but was not significant ($32.82{\pm}14.33$ ms vs. $40.36{\pm}21.40$ms, p=0.078). ApEn (Approximate Entrophy) was significantly increased in MDD group than normal control group ($1.13{\pm}0.11$ vs. $0.91{\pm}0.18$, p<0.001). ApEn was correlated with LDL level (r=0.277, p=0.028), HAM-D scores (r=0.534, p<0.001) and HAM-A scores (r=0.470, p<0.001). Conclusions: MDD patients showed increased ApEn, one of the HRV measurement. And this ApEn was correlated with LDL, HAM-D and HAM-A scores. In this study, the analysis of ApEn would be a useful test of MDD.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.107-117
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• 2024

This study investigated temporal changes in forest physical variables and their effects on thermal comfort and physiological and psychological responses. Environmental factors (air temperature, mean radiant temperature, wind speed, and relative humidity), the predicted mean vote (PMV), and the predicted percentage of dissatisfied (PPD) visitors were continuously measured between 9:00 AM and 6:00 PM. We assessed the physiological and psychological responses (heart rate variability, heart rate, oral temperature, blood pressure, pulse rate, thermal sensation vote, comfort sensation vote, and subjective feelings) of 30 male university students (average age: 21.7±1.9 years), who closed their eyes and relaxed for 5 minutes every hour. Examination of correlations between environmental factors and physiological responses showed that ① the mean radiant temperature, wind speed, and relative humidity significantly changed with time; ② PMV and PPD also showed significant changes over time, and the thermal sensation vote corresponded with PMV; however, the comfort sensation vote did not correspond with PPD; ③ Among the physiological responses, parasympathetic nerve activity, sympathetic nerve activity, heart rate, and diastolic blood pressure significantly varied with time, with parasympathetic nerve activity having the lowest value and sympathetic nerve activity the highest at the highest air temperature (2:00-4:00 PM); and ④ Air temperature, mean radiant temperature, and wind speed showed a negative correlation with parasympathetic nerve activity and a positive correlation with sympathetic nerve activity. These findings indicate that the relaxation effects of the forest environment depend on what time of day people are exposed to it, and the changes occurring in forest environmental factors over time modulate these effects.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.350-362
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• 1999

Background: Acute Respiratory failure which is developed after extubation in the weaning process from mechanical ventilation is an important cause of weaning failure. Once it was developed, endotracheal reintubation has been done for respiratory support. Noninvasive Positive Pressure Ventilation (NIPPV) has been used in the management of acute or chronic respiratory failure, as an alternative to endotracheal intubation, using via nasal or facial mask. In this study, we evaluated the usefulness of NIPPV as an alternative method of reintubation in patients who developed acute respiratory failure after extubation. Method: We retrospectively analyzed thirty one patients(eighteen males and thirteen females, mean ages $63\pm13.2$ years) who were developed acute respiratory failure within forty eight hours after extubation, or were extubated unintentionally at medical intensive care unit(MICU) of Asan Medical Center. NIPPV was applied to the patients. Ventilatory mode of NIPPV, level of ventilatory support and inspiratory oxygen concentration were adjusted according to the patient condition and results of blood gas analysis by the attending doctors at MICU. NIPPV was completely weaned when the patients maintained stable clinical condition under 8 $cmH_2O$ of pressure support level. Weaning success was defined as maintenance of stable spontaneous breathing more than forty eight hours after discontinuation of NIPPV. Respiratory rate, heart rate, arterial blood gas analysis, level of pressure support, and level of PEEP were monitored just before extubation, at thirty minutes, six hours, twenty four hours after initiation of NIPPV. They were also measured at just before weaning from NIPPV in success group, and just before reintubation in failure group. Results: NIPPV was successfully applied to thirty-one patients of thirty-two trials and one patient could not tolerated NIPPV longer than thirty minutes. Endotracheal reintubation was successfully obviated in fourteen patients (45%) among them. There was no difference in age, sex, APACHE III score on admission at MICU, duration of intubation, interval from extubation to initiation of NIPPV, baseline heart rate, respiratory rate, arterial blood gas, and $PaO_2/FiO_2$ between the success and the failure group. Heart rate and respiration rate were significantly decreased with increase $SaO_2$ after thirty minutes of NIPPV in both groups(p<0.05). However, in the patients of failure group, heart rate and respiratory rate were increased again with decrease in $SaO_2$ leading to endotracheal reintubation. The success rate of NIPPV treatment was significantly higher in the patients with COPD compared to other diseases(62% vs 39%) (p=0.007). The causes of failure were deterioration of arterial blood gas without aggravation of underlying disease(n=9), aggravation of undelying disease(n=5), mask intolerance(n=2), and retained airway secretion(n=l). Conclusion: NIPPV would be a useful therapeutic alternative which can avoid reintubation in patient who developed acute respiratory failure after extubation.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.2
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• pp.50-55
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• 2015

The noise of MRI shooting is 100dB loud and has an intensive psychological and physiological influences on the human body. ECG signals were measured by experimental methods, while wearing earplugs for 15 minutes in the stable state. Then the ECG signals were measured for 30 minutes while listening to about 100dB of sound in a MRI equipment. In this study, the heart rate variability of men and women was analyzed according to the MRI noise stress level through the frequency analysis. As the MRI noise level is about 100dB, HRV analysis resulted in an imbalance between the sympathetic and parasympathetic. During the period from the resting state up to 10 minutes, the maximum stress state was shown. This study will encourage MRI workers to take interests in hearing protection for the patient and to make objective indicators about MRI noises.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.844-849
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• 1996

During the 2 years period, we hav performed acute peritoneal dialysis in twenty two children after cardiopulmonary bypass among 198 patients who underwent surgery due to complicated congenital heart diseAses . were fluid over- load (10 cases), oliguria (9 cases) and hyperkalemia (3 cases). Bypass time greAter than 90 minutes was a predictor of the need for dialysis(p< 0.05). Five neonates (38 %) operated on instituted peritoneal dialysis but it was insignificant determinant factor (p 08). Sixteen patients recovered their renal suction, but 4 patients died due to respirAtory fAilure or sepsis. All the patients which could not recover their renal function, expired although the renal failure was not re- sponsible for the mortality. We think that early peritoneal dialysis is helpful in cases of oliguia, fluid overload or hyperkalemia after cradiopulmonary bypass.