• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.705-711
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• 2013

QRS detection of ECG is the most popular and easy way to detect cardiac-disease. But it is difficult to analyze the ECG signal because of various noise types. Also in the healthcare system that must continuously monitor people's situation, it is necessary to process ECG signal in realtime. In other words, the design of algorithm that exactly detects QRS wave using minimal computation and classifies PVC by analyzing the persons's physical condition and/or environment is needed. Thus, efficient QRS detection and PVC classification based on profiling method is presented in this paper. For this purpose, we detected QRS through the preprocessing method using morphological filter, adaptive threshold, and window. Also, we applied profiling method to classify each patient's normal cardiac behavior through hash function. The performance of R wave detection, normal beat and PVC classification is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.77% in R wave detection and the rate of 0.65% in normal beat classification error and 93.29% in PVC classification.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.6
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• pp.43-50
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• 2011

Currently, conventional security methods including IC card or password type method are quickly switched into biometric security systems in various applications and the electrocardiogram (ECG) has been considered as one of novel biometrics way. However, conventional ECG based biometrics used lead II signal which conventionally used for formulaic signal to heart disease diagnosis and it is not suitable for biometrics since it is rather difficult to find consistent features for heart disease patents. To overcome this problem, we developed new biometrics system using ECG lead III signals. For wave extraction, signal peak points are extracted through AAV algorithm. For feature selection, extracted waves are categorized into one of four wave types and total twenty two features including number of vertices, wave shapes, amplitude information and interval information are extracted based on their wave types. Experimental results for thirty-six people showed 100% specificity, 95.59% sensitivity and 99.17% of overall identification accuracy.

• Journal of Chest Surgery
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• v.37 no.12
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• pp.1029-1031
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• 2004

We had expierienced pulmonary lymphangioleiomyomatosis(LAM) with bilateral chylothorax and chylous ascites. A twenty-one-year-old lass with chief complaint of abdominal pain was admitted through the emergency room. She received emergent pelvicoscopic surgery for the rupture of the right corpus luteum. We aspirated 1000ml of the uncoagulated blood. The bleeding point was cautherized electrically. LAM was diagnosed with tissue from the retroperitoneum. Chylous ascites and bilateral chylothorax were occurred despite of various treatments. On thoracotomy, bullous changed lung and lymphatic leakage from visceral and parietal pleura were observed. She died of respiratory insufficiency and general weakness after 6 months from admission.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.57-58
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• 2014

본 연구에서는 여러 가지 생체 신호 중 심전도 신호를 대상으로 하여 개인별 구분이 가능한 특이점이 검출 되는지 기계 학습을 통하여 검증하였다. 심장 질환이 없는 정상인을 대상으로 수집한 신호로 부터 8가지 기점 특징을 추출하였으며, 동일 오류율과 AUC를 평가 척도로 하여 SVM 분류기를 이용한 경우 개인별 특이점이 효과적으로 구분됨을 확인하였다.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.761-766
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• 2023

In this paper, TI was measured to classify the presence or absence of mild left ventricular diastolic dysfunction. Of the total 306 data, 206 were used as training data and 100 were used as test data, and the machine learning models used for classification used SVM and KNN. As a result, it was confirmed that SVM showed relatively higher accuracy than KNN and was more useful in diagnosing the presence of left ventricular diastolic dysfunction. In future research, it is expected that classification performance can be further improved by adding various indicators that evaluate not only TI but also cardiac function and securing more data. Furthermore, it is expected to be used as basic data to predict and classify other diseases and solve the problem of insufficient medical manpower compared to the increasing number of tests.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1123-1128
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• 1996

A clinical study was performed on 152 cases of surgical esophageal disease treated by the Department of Thoracic & Cardiovascular Surgery of Korea University Hospital from Jan. 1989 through July 1994. The most common esophageal disease was cancer which was seen in 73 cases (48%) among 152 cases. All were treated surgically' 52 patients (71%) were managed by curative or palliative resection with reconstruction and feeding gastrostomy or jejunostomy, otherwise Celestine tube insertion was performed on the remaining 21 patients for palliatio'n. Esophageal leiomyoma occurred in 6 cases(3.9%), among them 1 case was performed with trio recoscopic enucleation . Achalasia were in 7 cases (4.6%) and was treated with modified Heller's m otomy and with Belsey Mark IV operation. Diverticulum were in 11 cases (7.2%). Esophageal stricture occurred in 20 cases (14.1 %) and 17 of 20 cases were managed with bypass surgery. Esophageal perforation was seen in 20 cases, its cause was instrumental trauma in 7 cases, stab wound in 4 cases, foreign body in 4 cases, spontaneous perforation in 3 cases, and others 1 case Other disease including congenital lesion was seen In 1 Scases.

• Journal of Chest Surgery
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• v.34 no.2
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• pp.162-166
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• 2001

배경: 흉선암은 드문 질환으로 치료경과 및 예후가 침윤성 흉선종에 비해 나쁜 것으로 알려져 있으며 병기의 분류나 병기에 따른 치료방법이 아직 표준화 되어있지 않아 치료에 어려운 점이 있다. 이에 본교실에서 흉선암으로 진단되었던 환자들의 피료방법 및 성적을 분석하여 그 결과를 보고하고자 한다. 대상 및 방법: 계명대학교 동산의료원 흉부외과학교실에서는 1984년 8월에서 흉선암으로 진단되었던 8례의 환자를 대상으로 의무기록을 참고하여 병기에 따른 치방법료 및 예후 등을 후향적으로 분석하였다. 결과: 연령은 23세에서 67세까지로 평균 46세였으며 전흉부통증이 주증상이었다. 조직학적으로는 임파상피양암(lymphoepithelioma-like carcinoma)이 2례, 편평상피암(squamous cell carcinoma)이 2례, 기저세포암(basaloid carcinoma)이 1례, 혼합형(mixed type)이 3례 있었다. 임상적 병기분류는 Masoka의 분류법을 사용하였으며 제I기 2례, 제II기 4례, 제III기 1례, 제IVAr기가 1례 있었다. 4례의 환자에서는 종양의 완전적출이 가능했으며 3례에서는 고식적 수술을 시행하였다. 1례의 환자는 주위조직으로의 침윤과 심낭에 퍼져있어 조직생검만을 시행하였다. 전례에서 보조적 항암치료를 받았고 술후 병기가 제III기 이상이거나 종양의 절제가 불완전했던 5례의 환자에서는 보조적 방사선치료를 병행하였다. 이들 중 5례에서 술후 보조적 항암치료 및 방사선치료를 받고 현재까지 생존해있다. 평균추적기간은 55.3$\pm$64.6 개원이었고, 3례의 환자는 사망하였으며 4례의 환자는 종양의 재발증거 없이 생존해있다. 결론: 종양의 조기진단과 완전종양적출후 적극적인 보조적 항암치료 및 방사선치료가 흉선암을 치료하는데 도움이 될 것으로 사료된다.

• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.349-356
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• 2012

In the diagnosis of coronary artery atheromatous plaque, Cardiac computed tomography (Cardiac Computed Tomographic Angiography: CCTA) compared with IVUS(Intravascular Ultrasound: IVUS) investigate the diagnostic accuracy, Interested in CCTA atheromatous plaque in computed tomography values (Hounsfield Unit: HU) try to find out. From April 2006 to August 2008 among coronary artery disease(Coronary Artery Disease: CAD) patients with confirmed or suspicious of CAD by CCTA performed atherosclerotic plaques and found 200 patients who underwent IVUS were enrolled. 200 patients who underwent CCTA and IVUS results from the 476 plaque was found, IVUS results of the soft plaque(n; 84), fibrous plaque(n; 63), mixed plaque (n; 97), calcific plaque(n; 232). The results are classified according to the IVUS plaque in HU in the soft plaque : $53.8{\pm}10.5$, fibrous plaque : $108.1{\pm}20.0$, mixed plaque : $371.2{\pm}113.1$, and calcific plaque : $731.0{\pm}160.4$. CCTA had sensitivity of 97% and confidence interval of 95.0-98.3. This study that is the diagnosis of coronary atheromatous plaque for using CCTA, we confirm the high sensitivity and the confidence interval Based on IVUS results CCTA atheromatous plaque with HU in the analysis could be classified to characterize in the treatment of patients with CAD is expected to help.

• Journal of Chest Surgery
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• v.36 no.8
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• pp.559-565
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• 2003

By improving the flow pattern in Fontan circuit, total cavopulmonary connection (TCPC) could result in a better outcome than atriopulmonary connection Fontan operation. For the patients with impaired hemodynamics after atriopulmonary Fontan connection, conversion to TCPC can be expected to bring hemodynamic and functional improvement. We studied the results of the revision of the previous Fontan connection to TCPC in patients with failed Fontan circulation. Material and method: From October1979 to June 2002, eight patients who had failed Fontan circulation, underwent revision of previous Fontan operation to TCPC at Yonsei University Hospital. Intracardiac anomalies of the patients were tricuspid atresia (n=4) and other functional single ventricles (n=4). Mean age at TCPC conversion was 14.0$\pm$7.0 years (range, 4.6~26.2 years) and median interval between initial Fontan operation and TCPC was 7.5 years (range, 2.4~14.3 years). All patients had various degree of symptoms and signs of right heart failure. NYHA functional class was 111 or IV in six patients. Paroxysmal atrial fibrillation (n:f), cyanosis (n=2), intraatrial thrombi (n=2), and protein losing enteropathy (PLE) (n=3) were also combined. The previous Fontan operation was revised to extracardiac conduit placement (n=7) and intraatrial lateral tunnel (n=1). Result: There was no operative death. Major morbidities included deep sternal infection (n=1), prolonged pleural effusion over two weeks (n=1), and temporary junctional lachyarrhythrnia (n=1). Postoperative central venous Pressure was lower than the preoperative value (17.9$\pm$3.5 vs. 14.9$\pm$1.0, p=0.049). Follow-up was complete in all patients and extended to 50,1 months (mean, 30.3$\pm$ 12.8 months). There was no late death. All patients were in NYHA class 1 or 11. Paroxysmal supraventricular tachycardia developed in a patient who underwent conversion to intraatrial lateral tunnel procedure, PLE was recurred in two patients among three patients who had had PLE before the convertsion. There was no newly developed PLE. Conclusion: Hemodynamic and functional improvement could be expected for the patients with Fontan circulatory failure after atriopulmonary connection by revision of their previous circulation to TCPC. The conversion could be performed with low risk of morbidity and mortality.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.4
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• pp.205-212
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• 2023

Among cardiac diseases, arrhythmias can lead to serious complications such as stroke, heart attack, and heart failure if left untreated, so continuous and accurate ECG monitoring is crucial for clinical care. However, the accurate interpretation of electrocardiogram (ECG) data is entirely dependent on medical doctors, which requires additional time and cost. Therefore, this paper proposes an arrhythmia recognition module for the purpose of developing a medical platform through the analysis of abnormal pulse waveforms based on Lifelogs. The proposed method is to convert ECG data into image format instead of time series data, apply visual pattern recognition technology, and then detect arrhythmia using CNN model. In order to validate the arrhythmia classification of the CNN model by image type conversion of ECG data proposed in this paper, the MIT-BIH arrhythmia dataset was used, and the result showed an accuracy of 97%.