• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.110-113
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• 2005

본 논문은 가중 퍼지소속함수 기반 신경망(Neural Network with Weighted fuzzy Membership Funcstions, NEWFM)을 이용하여 심전도 신호로부터 조기심실수축(Premature Ventricular Contraction, PVC)을 판별하는 퍼지규칙을 추출하고 있다. NEWFM은 자기적응적(self adaptive) 가중 퍼지소속함수를 가지고 주어진 입력 데이터로부터 학습하여 퍼지규칙을 생성하고 이를 기반으로 정상 파형과 PVC 파형을 구분한다. 분류 성능 평가를 위하여 MIT/BIH 부정맥 데이터 베이스를 사용하였으며, NEWFM의 입력은 심전도의 파형에 웨이블릿 변환을 적용하여 추출된 웨이블릿 계수를 사용하였다. 여기에 비중복면적 분산 측정법을 적용하여 중요도가 낮은 계수를 제거하면서 최소의 m 개 특징입력만을 사용한 하이퍼박스로 단순화 시킨다. 이러한 방법으로 추출된 2개의 웨이블릿 계수를 사용한 퍼지규칙은 $96\%$의 PVC 분류성능을 보여준다.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.239-247
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• 1999

We estimated the changes of ECG and electrolytes in serum after intravenous administration of Succinylcholine Chloride (SCC), 0.15 mg/kg in ten normal mongrel dogs (mean 13 kg). Hyperkalemia was observed in the highest level by 6.46$\pm$0.8 mEq/L at ten minutes after the administration of SCC. The ECG appeared temporary the most severe changes as the increased T wave, the disappeared P wave, the prolonged of conduction times (PR, QTc intervals and QRS complex), and arrhythmia as ventricular premature contraction at 3 and 5 minutes after the administration SCC. Therefore, the changes of ECG after administration of SCC were suggested to specific and independent from hyperkalemic changes. Because these changes were observed to differ from ECG by hyperkalemia, and the highest period of $K^＋$value in serum differ from the appearance period of severe changes of ECG and arrhythmia by SCC.

• Journal of Chest Surgery
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• v.25 no.6
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• pp.672-677
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• 1992

This is a clinical review of the results from electric cardioversion and pharmacological therapy used in our hospital for reverting cardiac arrythmia in patients with mitral valve surgery between Jan. 1990 and Jun. 1991. Of 62 evaluated patients, 16 patients had regular sinus rhythm and the other 46 had arrhythmias [42; atrial fibrillation 1; atrial flutter 1; premature ventricular contraction] preoperatively. In 2 of patients with sinus rhythm, atrial fibrillation newly developed after surgery and was converted into sinus rhythm soon by intravenous administration of digoxin. Remaining 14 patient resumed sinus rhythm spontaneously. In patients with preoperative arrythmia, 3 patients reverted into sinus rhythm from atrial fibrillation by electric cardioversion at operative field, 1 patient by lidocain and mexiletine, 4 patients by combined use of digoxin and verapamil, 4 patients by 2 times of oral quinidine and 9 patient by long term use of oral amiodarone. Throughout this consecutive trials of anti-arrhythmic drugs and electric cardioversion, Conversion into normal sinus rhythm occurred in 48% of patients with arrhythmia developed after mitral valve surgery.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.7
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• pp.99-106
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• 1996

Estimation and removal procedures for baseline drift have been developed using linear, cubic spline, and bilineared transformed high pass filter. Linear and cubic spline interpolation with the PQ and TP segmens, which are considered to be isoelectric, as fiducial points ahve been estimated respectively. For a quantitative validation of the estimation procedure, 4 ECGs with arfificial baseline drift were constructed and analyzed by mean square error calculations and amplitude histograms. Also real ECGs were analyzed in a test set of the CSE data set 3 and set 4. Baseline drift detecton rule were designed and new method for the decision of fiducial point were constructed to avoid distorting as the case of premature ventricular or atrial contraction. From these comparison, proposed cubic spline method with PQ and TP segment (CS_PQ & TP) emerged as the most efficient method.

• The Korean Nurse
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• v.33 no.4
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• pp.62-85
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• 1994

The data were analyzed by using an S. P. S. S. computerized program for mean, standard deviation, percentage and paired t-test. The results of this study were as follows: 1. The increase in $PaO_2$ after hyperoxygenation and hyperinflation was highly statistically significant(p=0.041), and the increase in $PaO_2$ immediately after suctioning was not significant (p=0.752). The time of lowest $PaO_2$ was 30 seconds after the endotracheal suction. 2. The occurrance of cardiac arrhythmia after the endotracheal suction included sinus tachycardia, sinus arrhythmia, sinus bradycardia, premature atrial contraction (PAC), and premature ventricular contraction (PVC). The most frequent cardiac arrhythmia was sinus tachycardia (a subjects). Sinus arrhythmia was observed in 5 subjects and continued till 10 minutes after suctioning in two of these. Sinus bradycardia occurred in only 3 subjects and among them, 1 subjects shows sinus arrythmia till 10 minutes after suctioning along. PAC was observed in only one subject and continued till five minutes after suctining along with sinus arrhythmia. PVC was observed in three subjects: it lasted for only 30 seconds after suctioning in two subjects. but continued for 10 minutes after suctioning in the third. 6 subjects manifested two kinds of Cardiac arrhythmia Three of them showed sinus tachycardia with PVC, another 2 showed sinus bradycardia with sinus arrhythmia, and the other subject showed sinus arrhythmia with PAC. 3. The increases in heart rate during the endotracheal suction immediately after and at 30 seconds after suctioning were statistically significant (p=0.005). The increase in heart rate at one minute after suctioning was also significant (p=0.023). The increase in heart rate continued until 10 minutes after the endotracheal suction, but was not statistically significant In this study, endotracheal suctioning with hyperoxygenation and hyperinflation was effective in preventing a decrease in $PaO_2$ after suctioning, but not in preventing cardiac arrhythmias. Nurses should be aware of the complications of endotracheal suctioning and do effective hyperoxygenation and hyperinflation before and after suctioning. Further research is needed to develop a efficient endotracheal suction method which will minimize complications. This study needs to be replicated with different population of patients intubatted or having a tracheostomy, specifically, patients who cardiac or pulmonary desease. The data were analyzed by using an S. P. S. S. computerized program for mean, standard deviation, percentage and paired t-test. The results of this study were as follows: 1. The increase in $PaO_2$ after hyperoxygenation and hyperinflation was highly statistically significant(p=0.041), and the increase in $PaO_2$ immediately after suctioning was not significant (p=0.752). The time of lowest $PaO_2$ was 30 seconds after the endotracheal suction. 2. The occurrance of cardiac arrhythmia after the endotracheal suction included sinus tachycardia, sinus arrhythmia, sinus bradycardia, premature atrial contraction (PAC), and premature ventricular contraction (PVC). The most frequent cardiac arrhythmia was sinus tachycardia (a subjects). Sinus arrhythmia was observed in 5 subjects and continued till 10 minutes after suctioning in two of these. Sinus bradycardia occurred in only 3 subjects and among them, 1 subjects shows sinus arrythmia till 10 minutes after suctioning along. PAC was observed in only one subject and continued till five minutes after suctining along with sinus arrhythmia. PVC was observed in three subjects: it lasted for only 30 seconds after suctioning in two subjects. but continued for 10 minutes after suctioning in the third. 6 subjects manifested two kinds of Cardiac arrhythmia Three of them showed sinus tachycardia with PVC, another 2 showed sinus bradycardia with sinus arrhythmia, and the other subject showed sinus arrhythmia with PAC. 3. The increases in heart rate during the endotracheal suction immediately after and at 30 seconds after suctioning were statistically significant (p=0.005). The increase in heart rate at one minute after suctioning was also significant (p=0.023). The increase in heart rate continued until 10 minutes after the endotracheal suction, but was not statistically significant In this study, endotracheal suctioning with hyperoxygenation and hyperinflation was effective in preventing a decrease in $PaO_2$ after suctioning, but not in preventing cardiac arrhythmias. Nurses should be aware of the complications of endotracheal suctioning and do effective hyperoxygenation and hyperinflation before and after suctioning. Further research is needed to develop a efficient endotracheal suction method which will minimize complications. This study needs to be replicated with different population of patients intubatted or having a tracheostomy, specifically, patients who cardiac or pulmonary desease.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.427-436
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• 2016

In general, QRS duration represent a distance of Q start and S end point. However, since criteria of QRS duration are vague and Q, S point is not detected accurately, arrhythmia classification performance can be reduced. In this paper, we propose extraction of Q, S start and end point RS feature based on phase transition tracking method after we detected R wave that is large peak of electrocardiogram(ECG) signal. For this purpose, we detected R wave, from noise-free ECG signal through the preprocessing method. Also, we classified QRS pattern through differentiation value of ECG signal and extracted Q, S start and end point by tracking direction and count of phase based on R wave. The performance of R wave detection is evaluated by using 48 record of MIT-BIH arrhythmia database. The achieved scores indicate the average detection rate of 99.60%. PVC classification is evaluated by using 9 record of MIT-BIH arrhythmia database that included over 30 premature ventricular contraction(PVC). The achieved scores indicate the average detection rate of 94.12% in PVC.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.85-88
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• 2011

Purpose: Takotsubo cardiomyopathy is a relatively uncommon type of stress-induced cardiomyopathy characterized by transient left ventricular regional wall motion abnormalities. Emotional and physical stresses play a key role in this type of cardiomyopathy in postmenopausal women. The current hypothesis is that the syndrome represents a form of catecholamine surge due to stress or epinephrine-mediated acute myocardial stunning. Methods: A 44-year-old woman had suffered premature ventricular contraction following a cardiogenic shock during a breast augmentation surgery under enflurane anesthesia and tumescent solution infiltration. She was treated with cardiopulmonary resuscitation at a local clinic. Then she was brought to the Emergency Department of the authors' hospital. Results: The woman's echocardiogram showed an ejection fraction of 20~25% with associated basal hyperkinesis and left ventricular apical ballooning. The patient was admitted to the ICU and required inotropic support for two weeks. The patient's condition dramatically improved, and her ejection fraction returned to 70%. Conclusion: It is believed that there were multiple triggering factors of the onset of Takotsubo cardiomyopathy in the woman's social and family history, including infiltration of a large volume of the tumescent solution and VPCs induced by enflurane anesthesia without premedication. The importance of careful history-taking, careful pre-operative consultation on psychological suffering especially for breast surgery, premedication before surgery, patient reassurance, and post-operative psychosocial and emotional assistance was again seen in this case.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1531-1539
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• 2014

Premature ventricular contraction(PVC) is the most common disease among arrhythmia and it may cause serious situations such as ventricular fibrillation and ventricular tachycardia. Nevertheless personalized difference of ECG signal exist, performance degradation occurs because of carrying out diagnosis by general classification rule. In other words, the design of algorithm that exactly detects abnormal signal and classifies PVC by analyzing the persons's physical condition and/or environment and variable QRS pattern is needed. Thus, PVC classification by personalized abnormal signal detection and QRS pattern variability is presented in this paper. For this purpose, we detected R wave through the preprocessing method and subtractive operation method and selected abnormal signal sets. Also, we classified PVC in realtime through QS interval and R wave amplitude. The performance of abnormal beat detection and PVC classification is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate the average of 98.33% in abnormal beat classification error and 94.46% in PVC classification.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.91-98
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• 2017

Previous works for detecting arrhythmia have mostly used nonlinear method such as artificial neural network, fuzzy theory, support vector machine to increase classification accuracy. Most methods require higher computational cost and larger processing time. Therefore it is necessary to design efficient algorithm that classifies PVC(premature ventricular contraction) and decreases computational cost by accurately detecting minimal feature point based on only R peak through optimal R wave. We propose an optimal R wave detection and PVC classification method through extracting minimal feature point in IoT environment. For this purpose, we detected R wave through optimal threshold value and extracted RR interval and R peak pattern from noise-free ECG signal through the preprocessing method. Also, we classified PVC in realtime through RR interval and R peak pattern. The performance of R wave detection and PVC classification is evaluated by using record of MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.758% in R wave detection and the rate of 93.94% in PVC classification.

• Journal of Chest Surgery
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• v.26 no.7
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• pp.526-531
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• 1993

Sixty-one consecutive patients with coronary artery bypass graft for myocardial revascularization were retrospectively reviewed to analyze various pattern of postoperative complication and death during hospital stay from Nov. 1988 to Oct. 1992. Fortytwo of the patients were male and nineteen female. The mean age was 56 and 51 years in male and female. Preoperative diagnosises were unstable angina in 14 of patients, stable angina in 28, postmyocardial infarction state in 15, and state of failed percutaneous transluminal coronary angioplasty in 4. 141 stenosed coronary arteries were bypassed with use of 20 pedicled internal mammary artery and 124 reversed saphenous vein grafts. Postoperative complications and perioperative death were as follows: 1. Of 61 patients undergoing operation, peri and postoperative over all complication occured in 15 patients [ 25% ]; newly developed myocardial infarction in 4, intractable cardiac arrhythmia including atrial fibrillation and frequent ventricular premature contraction in 3, bleeding from gastrointestinal tract in 2, persistent vegetative state as a sequele of brain hypoxia in 1, wound necrosis in 1, left hemidiaphragmatic palsy in 3 and poor blood flow through graft in 2. 2. Operative mortality was 8%[5 patients]. 3 out of these died in operating room; 1 patient by bleeding from rupture of calcified aortic wall, 1 by air embolism through left atrial vent catheter, 1 by low cardiac output syndrome. 2 patients died during hospital stay; 1 by acute respiratory distress syndrome with multiuple organ failure, 1 by brain death after delayed diagnosis of pericardial tamponade.