• Journal of Chest Surgery
• /
• 제24권2호
• /
• pp.171-181
• /
• 1991

Result of St. Jude Medical valve replacement are presented in 106 patients who underwent operation from January 1985 through July 1989. The patient were 52 males and 56 females. Total 136 of St. Jude Medical valves were implanted; 91 in mitral position, 45 in aortic position. The hospital mortality rate was 5.7%o[6 patients] and the late mortality rate was 2.0%[2 patients]. The causes of death were low cardiac output in 5, iatrogenic right ventricular rupture in 1, heart failure in 1, ventricular arrhythmia in l. And, the causes of valve related complication were anticoagulant related hemorrhage in 5 patients[0.03% /patient-year] and thromboembolism[0.01% /patient-year] in 2 patients. In conclusion, the performance of the St. Jude Medical valve compare most favorably with other artificial valves. But it remains still hazards of mechanical prosthesis such as thromboembolism and anticoagulant related hemorrhage.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1995년도 추계학술대회
• /
• pp.47-51
• /
• 1995

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2011년도 춘계학술발표대회
• /
• pp.10.1-10.1
• /
• 2011

Energy harvesting technologies converting external sources (such as thermal energy, vibration and mechanical energy from the nature sources of wind, waves or animal movements) into electrical energy is recently a highly demanding issue in the materials science community for making sustainable green environments. In particular, fabrication of usable nanogenerator attract the attention of many researchers because it can scavenge even the biomechanical energy inside the human body (such as heart beat, blood flow, muscle stretching, or eye blinking) by converging harvesting technology with implantable bio-devices. Herein, we describe procedure suitable for generating and printing a lead-free microstructured $BaTiO_3$ thin film nanogenerator on plastic substrates to overcome limitations appeared in conventional flexible ferroelectric devices. Flexible $BaTiO_3$ thin film nanogenerator was fabricated and the piezoelectric properties and mechanically stability of ferroelectric devices were characterized. From the results, we demonstrate the highly efficient and stable performance of $BaTiO_3$ thin film nanogenerator and the integration of bio-eco-compatible ferroelectric materials may enable innovative opportunities for artificial skin and energy harvesting system.

• Journal of Chest Surgery
• /
• 제10권1호
• /
• pp.106-112
• /
• 1977

Transposition of the great arteries is one of the commonest forms of severe congenital heart disease and produces severe cyanosis threatening survival from the day of birth. Anatomical anomalies which the aorta arises from the infundibulum of the right ventricle and the pulmonary artery arises from the outflow tract of the left ventricle make the deranged circulation. Survival is possible only if additional anomalies are present which allow mixing of the pulmonary and systemic circulations. Preoperative diagnosis as TGA was taken on the 15 day old female via the preoperative examination and the right cordioangiography. As palliative treatment for cyanosis, Blalock-Hanlon operation was performed in this patient. The results were good as 54 mmHg changed from 27 mmHg of $PO_2$ in aorta, but sudden cardiac arrest was developed in postoperative 12 hours. In order to confirm the cause of death and the cardiac anomalies, autopsy was performed on the date of death. The diagnosis of the autopsy showed; [1] Transposition of the Great Arteries. [2] Patent Ductus Arteriosus. [3] Patent Foramen Ovale. [4] Ventricular Septal Defect, 2 Muscular Type. [5] Double Ureter, Right. [6] Artificial Atrial Septal Defect. [7] Total Collapse of the left lung and Intraparenchymal hemorrhage of right lung.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2001년도 춘계학술대회논문집
• /
• pp.559-564
• /
• 2001

In order to apply into a compact and reliable centrifugal blood pump, this paper introduces a self-bearing motor in which a rotor is rotated without contact. The rotor is actively controlled in only radial directions, while the axial and tilting motions are passively stable owing to the disk-shape structure of the rotor. A prototype was made in outer-rotor type that is far better in the compactness than inner-rotor type. The prototype could be driven up to 8000 rpm with the rotor vibration under 0.12mm. The maximum cardiac output and pressure head were 9 L/min and over 200 mmHg, respectively. These experimental results show that the proposed self-bearing motor has sufficient performance for application to a real blood pump.

• 대한의용생체공학회:의공학회지
• /
• 제17권2호
• /
• pp.215-220
• /
• 1996

Impact force and strains induced by impact between the occluder and the struts have been measured with force sensor and strain gages. The maximum reaction force was about 25N, and the calculated impact force on the root of the struts amount about 9-17W. Impact force on the inlet strut is greater than that of the outlet strut, but the strain on the outlet strut is much higher than that of the inlet strut. These values might cause severe damage on the valve in the critical cases. The results of this study may be extended for the analysis of the endurance limit and optimal design of the struts and occluder.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 추계학술대회
• /
• pp.439-442
• /
• 1997

In our research, we will extract diagnostic parameters by LPC method and wavelet transform. Then, we will design artificial neural network which is based on RBF that can express input features in terms of fuzzy. Because PVC(Premature Ventricular Contraction) has possibility to cause heart attack, the detection of PVC is a very significant problem. To deal with this problem, LPC method which gives different coefficients or different morphologies and wavelet transform which has superior localization nature of time-frequency, are used to extract effective parameters or classification of normal and PVC. Because RBF network can allocate an input feature to the membership degree of each category, total system will be more flexible.

• Journal of Chest Surgery
• /
• 제53권2호
• /
• pp.82-85
• /
• 2020

Insertion of an epicardial pacemaker is a useful treatment for pediatric patients with an abnormal heart rhythm. However, there are limitations and concerns when implanting epicardial pacemakers in infants and neonates due to their small body size. We report a patient who experienced rare complications after implantation of a permanent pacemaker.

• 대한가정학회지
• /
• 제42권1호
• /
• pp.99-113
• /
• 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
• /
• 대한의용생체공학회 1995년도 춘계학술대회
• /
• pp.259-261
• /
• 1995