• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1139-1143
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• 2007

For the possible application of monitoring or diagnosing heart sounds in an ubiquitous healthcare environment. a small and light electro-stethoscope that can be attached in human body should be exploited. With this aim, this study proposes a new style of electro-stethoscope device that is composed of four hardware modules in wearable style. For this ambulatory heart sound collecting device, the several tests must be performed to check portability and material capability for collecting heart sounds. It turned out to be that the multi-channel electro-stethoscope can detect heart sound signals well even if it is not pinpointed in the accurate stethoscope point on a heart. Consequently, our ambulatory electro-stethoscope hardware system can be applied to monitor or diagnose abnormal heart sounds in the ubiquitous healthcare system.

• Journal of the Korean Mathematical Society
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• v.43 no.4
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• pp.885-897
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• 2006

A new mathematical model of pumping heart coupled to lumped compartments of blood circulation is presented. This lumped pulsatile cardiovascular model consists of eight compartments of the body that include pumping heart, the systemic circulation, and the pulmonary circulation. The governing equations for the pressure and volume in each vascular compartment are derived from the following equations: Ohm's law, conservation of volume, and the definition of compliances. The pumping heart is modeled by the time-dependent linear curves of compliances in the heart. We show that the numerical results in normal case are in agreement with corresponding data found in the literature. We extend the developed lumped model of circulation in normal case into a specific model for arrhythmia. These models provide valuable tools in examining and understanding cardiovascular diseases.

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.343-343
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• 2005

• Journal of Chest Surgery
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• v.17 no.2
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• pp.305-314
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• 1984

From May 1977 to April 1984, 204 cases of open heart surgery were performed under cardiopulmonary bypass. There were 99 male and 105 female patients ranging in age from 19 months to 58 years. 136 cases [66.7%] were congenital heart disease, and 68 cases [33.3%] were acquired heart disease, which were 66 valvular disease [97.1%], 1 IVC obstruction, and 1 myxoma. There were 136 congenital heart anomaly with 16 operative deaths [11.8%], consisting of 94 acyanotic cases with 7 death [7.4%] and 42 cases of cyanotic cases with 9 deaths [21.4%]. In 66 patients of acquired valvular disease, 52 valves were implanted; 47 mitral valve replacement with 4 death [8.5%] and 5 double valve replacement [MVR+AVR] with 1 death [20%]. Postoperative, warfarin sodium was medicated with checking prothrombin time. Finally, the operative mortality was 11.8% in congenital anomaly, and 11.8% in acquired heart disease, overall mortality rate was 8.5%.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.383-390
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• 1985

108 cases of open heart surgery were done at our department in 1984. There were 58 male and 50 female patients ranging in age from 20 months to 52 years. 75 cases were congenital heart disease, and 33 cases were acquired heart disease. There were 75 congenital heart anomalies with 5 operative deaths [6.7%], consisting of 62 acyanotic cases with 2 deaths [3.2%] and 13 cases of cyanotic cases with 3 deaths [23.1]. In 33 patients of acquired valvular disease, 29 valves were implanted; 20 mitral valve replacement with 2 death [10%], 2 aortic valve replacement with 1 death [50%], 2 double valve replacement [MVR+AVR] and 2 open mitral commissurotomy plus aortic valve replacement with no death. Postoperative, Warfarin sodium was medicated with checking prothrombin time. Finally, the operative mortality was 9.2% in congenital anomaly, and 9.1% in acquired heart disease, overall mortality rate was 9.3%.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.398-406
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• 1985

103 cases of open heart surgery were performed in the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital in 1984. There were 90 congenital cardiac anomaly and 13 acquired heart diseases. Out of 90 congenital cardiac anomaly, 63 cases of acyanotic group and 27 cases of cyanotic group were noted. In 63 cases of acyanotic group, 11 ASD, 45 VSD and 7 other acyanotic anomaly were included. In 27 cases of cyanotic group, 4 Trilogy of Fallot, 15 TOF, 3 Pentalogy of Gasul and 5 other cyanotic anomaly were found. Among 13 cases of acquired heart diseases, 12 valvular lesions and 1 atrial myxoma were noted. Two open mitral commissurotomy and ten valve replacements were performed for 12 valve lesions. The frequent complications were acute respiratory insufficiency and low cardiac output syndrome occurred in 5 cases. The perioperative mortality was 4.8% in acyanotic congenital cardiac anomaly, 7.4% in cyanotic congenital cardiac anomaly, and 0% in acquired heart diseases. Overall mortality for 103 cases of open heart surgery was 4.9%.

• Journal of Chest Surgery
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• v.20 no.1
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• pp.148-155
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• 1987

From May 1977 to June 1986, 500 cases of open heart surgery were performed under the cardiopulmonary bypass. There were 278 male and 222 female patients ranging from 6 months to 69 years. 363 cases[73.6%] were congenital heart diseases, and 137 cases[27.4%] were acquired heart diseases, which were 33 valvular diseases, 3 myxomas and 1 IVC obstruction. There were 363 congenital heart anomaly with 35 operative deaths[9.6%], consisting of 279 acyanotic cases with 12 deaths [4.3%] and 85 cases of cyanotic cases with 23 deaths[28.4%]. In 133 patients of acquired valvular disease, 124 valves were implanted and operative death of valvular disease was 12%. Finally the operative mortality was 9.6% in congenital anomaly, and 12.4% in acquired heart disease, overall mortality rate was 10.4%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1194-1199
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• 2009

Heart rate may be a very important parameter in human health. To extract heart rate, the electrocardiogram(ECG) is commonly used. But the ECG acquisition procedure is very complex. On the other hand, the acquisition of pulse wave or photoplethysmogram(PPG) is very easy. However, the peak of PPG is not so sharp as ECG. This study tries to enhance the performance of peak detection in PPG signal. The method uses the average slopes around the main peak. The crossing point of the increasing and the decreasing slopes is selected as the peak point of heart rate period. The proposed method showed smoothed heart rate graph and reduced irregularity in heart rate values.

• Journal of Biomedical Engineering Research
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• v.31 no.2
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• pp.170-175
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• 2010

A method of measuring heart rate using photoplethysmograph(PPG) signal during exercise is proposed. PPG's are composed of strong base tones and their harmonics, and the strong base tones are trackable by the adaptive notch filter (ANF) which adjusts its coefficients to minimize the output power. The proposed heart rate measurement algorithm continuously notches the frequency component with the maximum power in the measured PPG, so that the fundamental frequency corresponding to heart rate is traced. We also presents methods of detecting degeneration and impulsive noise blocks to minimize the coefficient fluctuation. Experiments were conducted using real PPG signals captured during exercise. Results showed that the proposed algorithm is capable of consistently tracking the heart rate embedded in the noisy PPG's.

• The Korean Journal of Health Service Management
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• v.7 no.3
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• pp.111-123
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• 2013

The purpose of this study was to identify factors affecting stress and adaptation in newborn congenital heart disease patients of parents. Data were obtained through questionnaires from 181 newborn congenital heart disease inpatients of parents from P university in Y city. The data were analyzed SPSS 18.0, using descriptive statistics, Pearson correlation coefficients and stepwise multiple regression. Stress was negative correlated with level of patents adaptation. Social support, marital communication and family cohesion were positive correlated with level of patents adaptation. The explained variances for patents adaptation were 45.2% and factors affecting patients adaptation were congenital heart disease, family cohesion, stress, social support and marital communication. Educational intervention program for parents of newborn with congenital heart disease, reduce stress, and to increase the adaptation will be developed.