• Journal of Chest Surgery
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• v.53 no.2
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• pp.79-81
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• 2020

Treatment options for children with end-stage heart failure are limited. We report the first case of a successful pediatric heart transplantation bridged with a durable left ventricular assist device in Korea. A 10-month-old female infant with dilated cardiomyopathy and left ventricular non-compaction was listed for heart transplantation. During the waiting period, the patient's status deteriorated. Therefore, we decided to provide support with a durable left ventricular assist device as a bridge to transplantation. The patient was successfully bridged to heart transplantation with effective support and without any major adverse events.

• Proceedings of the KTCVS Conference
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• 1993.06a
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• pp.121-121
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• 1993

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.702-712
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• 2016

A wrist watch type wearable cardiovascular monitoring device is proposed for continuous and convenient monitoring of the patient's cardiovascular system. For comprehensive monitoring of the patient's cardiovascular system, the concurrent electrocardiogram (ECG) and arterial pulse wave (APW) sensor front-end are fabricated in $0.18{\mu}m$ CMOS technology. The ECG sensor frontend achieves 84.6-dB CMRR and $2.3-{\mu}Vrms$-input referred noise with $30-{\mu}W$ power consumption. The APW sensor front-end achieves $3.2-V/{\Omega}$ sensitivity with accurate bio-impedance measurement lesser than 1% error, consuming only $984-{\mu}W$. The ECG and APW sensor front-end is combined with power management unit, micro controller unit (MCU), display and Bluetooth transceiver so that concurrently measured ECG and APW can be transmitted into smartphone, showing patient's cardiovascular state in real time. In order to verify operation of the cardiovascular monitoring system, cardiovascular indicator is extracted from the healthy volunteer. As a result, 5.74 m/second-pulse wave velocity (PWV), 79.1 beats/minute-heart rate (HR) and positive slope of b-d peak-accelerated arterial pulse wave (AAPW) are achieved, showing the volunteer's healthy cardiovascular state.

• Journal of Chest Surgery
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• v.55 no.5
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• pp.378-387
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• 2022

Background: Atrial fibrillation (Afib) is a marker of increased cardiovascular morbidity and mortality. Owing to the increased prevalence of Afib in patients undergoing cardiac surgery, assessing the effect of Afib on postsurgical outcomes is important. We aimed to analyze the effect of preoperative Afib on clinical outcomes in patients undergoing cardiac surgery using a large surgical database. Methods: This retrospective cohort study was based on the national health claims database established by the National Health Insurance Service of the Republic of Korea from 2009 to 2015. Diagnosis and procedure codes were used to identify diseases according to the International Statistical Classification of Diseases, 10th revision. Results: We included 1,037 patients (0.1%) who had undergone cardiac surgery from a randomized 1,000,000-patient cohort, and 15 patients (1.5%) treated with isolated surgical Afib ablation were excluded. Of these 1,022 patients, 412 (39.7%), 303 (29.2%), and 92 (9.0%) underwent coronary artery bypass, heart valve surgery, and Cox-maze surgery, respectively. Preoperative Afib was associated with higher patient mortality (p=0.028), regardless of the surgical procedure. Patients with preoperative Afib (n=190, 18.6%) experienced a higher cumulative risk of overall mortality (hazard ratio [HR], 1.435; 95% confidence interval [CI], 1.263-2.107; p=0.034). Subgroup analysis revealed a reduced risk of overall mortality with Cox-maze surgery in Afib patients (HR, 0.500; 95% CI, 0.266-0.938; p=0.031). Postoperative cerebral ischemia or hemorrhage events were not related to Afib. Conclusion: Preoperative Afib was independently associated with worse long-term postoperative outcomes after cardiac surgery. Concomitant Cox-maze surgery may improve the survival rate.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.674-679
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• 2016

According to the conventional studies on the noise and cardiovascular effect, railway noise is better associated with hypertension and adverse cardiovascular events than road traffic noise. But the underlying mechanisms remain unclear. We investigated the hypothesis that exposure to acute railway noise would the unfavorable effect of cardiovascular and autonomic system in healthy young subjects. Using a randomized, sham-controlled cross-over design, ten subjects were assigned to receive either an exposure to high speed train noise (84 dB) for 30 minutes or a control condition (non noise), separated by two days. Blood pressure, heart rate, augmentation index and heart rate variability as indices of cardiovascular and autonomic system function were measured at baseline, during, and recovery from two trials. The results show that exposure to acute railway noise significantly increased diastolic blood pressure and augmentation index, which may cause of adverse cardiovascular effects.

• Journal of Chest Surgery
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• v.23 no.3
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• pp.423-429
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• 1990

Authors designed a computer-based article data management system using a 16 bit IBM personal computer and dBASE IV program and applied it to the management of article data of the Korean Journal of Thoracic and Cardiovascular Surgery. In this system, authors developed a coding system for systemic classification of form and subject of articles and this coding system made the storage and inquiry of data easy and convenient. Using the coding system in this article management system, total 1476 sheets of articles in the Korean Journal of Thoracic and Cardiovascular Surgery were analyzed and briefly described according to their forms and subjects. If this article data management system including the coding system is applied to other Journals related to the department of thoracic and cardiovascular surgery, we can utilize them easily and conveniently for the save of time and effort in the data inquiry or article preparation.

• Journal of Chest Surgery
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• v.49 no.3
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• pp.151-156
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• 2016

Background: Survival of children experiencing cardiac arrest refractory to conventional cardiopulmonary resuscitation (CPR) is very poor. We sought to examine current era outcomes of extracorporeal CPR (ECPR) support for refractory arrest. Methods: Patients who were <18 years and underwent ECPR between November 2013 and January 2016 were including in this study. We retrospectively investigated patient medical records. Results: Twelve children, median age 6.6 months (range, 1 day to 11.7 years), required ECPR. patients' diseases spanned several categories: congenital heart disease (n=5), myocarditis (n=2), respiratory failure (n=2), septic shock (n=1), trauma (n=1), and post-cardiotomy arrest (n=1). Cannulation sites included the neck (n=8), chest (n=3), and neck to chest conversion (n=1). Median duration of extracorporeal membrane oxygenation was five days (range, 0 to 14 days). Extracorporeal membrane oxygenation was successfully discontinued in 10 (83.3%) patients. Nine patients (75%) survived more than seven days after support discontinuation and four patients (33.3%) survived and were discharged. Causes of death included ischemic brain injury (n=4), sepsis (n=3), and gastrointestinal bleeding (n=1). Conclusion: ECPR plays a valuable role in children experiencing refractory cardiac arrest. The weaning rate is acceptable; however, survival is related to other organ dysfunction and the severity of ischemic brain injury. ECPR prior to the emergence of end-organ injury and prevention of neurologic injury might enhance survival.

• Proceedings of the Korea Society for Simulation Conference
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• 2004.05a
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• pp.109-117
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• 2004

In this paper, we consider the aortic sinus baroreceptor, which is the most representative baroreceptor sensing the variance of pressure in the cardiovascular system, and propose heart activity control model to observe the effect of delay time in heart period and stroke volume under the regulation of baroreflex in the aortic sinus. The proposed heart activity baroreflex regulation model contains electric circuit sub-model. We constituted the time delay sub-model to observe sensitivity of heart activity baroreflex regulation model by using the variable value to represent the control signal transmission time from the output of baroreflex regulation model to efferent nerve through central nervous system. The simulation object of this model is to observe variability of the cardiovascular system by variable value in time delay sub-model. As simulation results, we observe three patterns of the cardiovascular system variability by the time delay, First, if the time delay over 2.5 second, aortic pressure and stroke volume and heart rate is observed nonperiodically and observed. Finally, if time delay under 0.1 second, then heart rate and aortic pressure-heart rate trajectory is maintained in stable state.

• Journal of Chest Surgery
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• v.23 no.2
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• pp.342-351
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• 1990

In recent years there are so many medical informations that surgeons should know to handle or analyze their large amount of surgical cases. Proper use of computer system offers new opportunities for the storage and manipulation of their hospital informations. But little is reported about which system, is appropriate, how much can we do with such a system, or what kind of work can be done with that, especially in the area of Thoracic and Cardiovascular Surgery section. Authors designed a computer-based patient file management system using 16 Bit AT IBM personal computer and dBASE IV program, and developed a coding system for the diagnosis and operation name, which offers the basis for the classification of the surgical patient data. And the result of some experiences which was got from the total surgical cases of Thoracic and Cardiovascular Section, Seoul District Armed Forces General Hospital during past 5years, was described.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1181-1188
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• 2004

This paper reviews the main aspects of cardiovascular system dynamics with emphasis on modeling hemodynamic characteristics using a lumped parameter approach. Methodological and physiological aspects of the circulation dynamics are summarized with the help of existing mathematical models: The main characteristics of the hemodynamic elements, such as the heart and arterial and venous systems, are first described. Lumped models of micro-circulation and pulmonary circulation are introduced. We also discuss the feedback control of cardiovascular system. The control pathways that participate in feedback mechanisms (baroreceptors and cardiopulmonary receptors) are described to explain the interaction between hemodynamics and autonomic nerve control in the circulation. Based on a set-point model, the computational aspects of reflex control are explained. In final chapter we present the present research trend in this field and discuss the future studies of cardiovascular system modeling.