• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.195-196
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• 2008

ECG 기반의 부정맥 자동 분류에 관한 연구는 지난 수십 년간 다양한 방법으로 연구되어 왔다. 많은 연구들이 부정맥을 구별해 낼 수 있는 특징 벡터를 찾아내기 위해 연구하였으나, 피험자의 ECG 특징이 각기 다르기 때문에 부정맥으로 인한 차이와 개인 간 차이를 구별하기 어려웠다. 생체데이터는 그 특성상 서로 다른 특징을 갖고 있으며, 다양한 특징을 가진 사람들에게 적용하기 위한 범용성과 부정맥 검출의 정확성 사이에 교환적 관계를 갖게 된다. 특히 ECG 데이터의 경우 사람 식별 데이터로 사용하고자 하는 연구가 있을 정도로 개인 간 편차가 분명하다. wavelet 분석방법은 다양한 mother wavelet을 사용할 수 있다는 점을 큰 장점으로 가지고 있으며, wavelet parameterization 기법을 사용하여 임의의 직교 wavelet basis를 발생시킬 수 있다. 본 논문은 wavelet parameterization을 사용하여 개인 간의 ECG 파형의 차이를 상쇄시키고, 부정맥의 차이만을 부각시킴으로써 ECG 기반의 부정맥 자동 분류 성능을 높이고자 하는데 목적이 있다.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.1-5
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• 2005

Pediatricians often encounter some electrocardiographic abnormalities in infants and children. However, treatment or referral to pediatric cardiologist is not indicated for all arrhythmias. Many of them are benign in nature. Benign arrhythmias can be defined as the arrhythmias that no serious problem currently exists and no treatment is needed. The prognosis of benign arrhythmias is so good that the condition will never be associated with future health problem. However, some of them are benign now, but have potential for variable degrees of change to a nonbenign condition and some form of follow-up is required. For the appropriate management of electrocardiographic abnormalities, not infrequently seen in infants and children, correct diagnosis of abnormal electrocardiogram and understanding of characteristics of arrhythmias are required.

• Journal of Chest Surgery
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• v.29 no.1
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• pp.99-102
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• 1996

Cardiac fibroma is a rare benign tumor of the heart that occurs primarily in infants and children. Prognosis depends on size, extent and site of tumor. Cardiac fibroma may invade the conduction system, papillary muscle and outflw of inflow tract of ventricle. In these situations, its clinical course is very poor Although operative mortality is high, surgical resection is treatment of choice because lethal arrhythmia and sudden death can be developed by the fibroma. A cardiac fibroma was successfully resected from the left ventricular myocardium of a 8 years old male patient in the Department of Thoracic and Cardiovascular Surgery, Chonbuk National University Hospital.

• Journal of Biomedical Engineering Research
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• v.7 no.2
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• pp.169-182
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• 1986

Pulsed ultrasonic Doppler system is a useful diagnostic instrument to measure blood-flow-velocity, velocity profile, and volume-blood-flow. This system is more powerful compare with 2-dimensional B-scan tissue image. A system has been deve- loped and ii being evaluated using TMS 32010 DSP. We use this DSP for the purpose of real-time spectrum analyzer to obtain spectrogram in singlegate pulsed Doppler system and for the serial comb filter to cancel clutter and zero crossing counter to estimate Doppler mean frequency in multigate pulsed Doppler system. The Doppler shift of the backscattered signals is sensed in a phase detector. This Doppler signal corresponds to the mean velocity over a some region in space defined by the ultrasonic beam dimensions, transmitted pulse duration, and transducer ban(iwidth. Multi- gate pulsed Doppler system enable the transcutaneous and simultaneous assessment of the velocities in a number of adjacent sample volumes as a continuous function of time. A multigate pulsed Doppler system processing the information originating from presented.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.134-137
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• 1994

In this paper, we describe an approach to ECG data coding based on a fractal theory of iterated contractive transformations defined piecewise. The main characteristic of this approach is that it relies on the assumption that signal redundancy can be efficiently captured and exploited through piecewise self-transformability on a block-wise basis. The variable range size technique is employed to reduce the reconstruction error. Large ranges are used for encoding the smooth waveform to yield high compression efficiency, and the smaller ranges are used for encoding rapidly varying parts of the signal to preserve the signal quality. The suggested algorithm was evaluated using MIT/BIH arrhythmia database. A high compression ratio is achieved with a relatively low reconstruction error.

• Journal of Biomedical Engineering Research
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• v.7 no.1
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• pp.53-58
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• 1986

This paper represent the design of a digital modem which transmits the ECG data from an ambulatory arrhythmia monitor over the telephone lines to a large hospital for the instantaneous interpretations. The digital modem provides on-line communications between the patient and the central computer located near cardiologists. For commercial telephone lines, the transmitting error rates of the digital modem were measured 200 times at a speed of 300 baud. In those measurements, the block errors-results, due to the misinterpretation of start and stop bits, did not occur, The data bit errors which were due to a single bit interpreted incorrectly were 0.78 (bits/10 ) . Since the acceptable data bit error limit is 10 per 106 bits transmitted, the digital modem designed in this paper can be used for the clinical applications without any difficulty.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1276-1279
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• 1987

Cardiac arrhythmias are associated with electrical Instability and, hence, with abnormal mechanical activity of the heart in many cases, arrhythmias can be treated with drugs or electric shock to control and/or stop them. Hence fast arrhythmia detection is very important. In this paper RR interval, QRS width, and morphology are used for diagnosis and QRS complex is detected by hardware system. hence diagnosing time is shorten. Moreover doctors or nurses who have little knowledge of computer manipulation can get the Information of Patient's ECG by showing characteristics of abnormal waveform and by mapping graphs of RR interval .vs. QRS width and RR interval .vs. morphology on screen.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1230-1233
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• 1998

The Cox-Maze procedure was developed as a cure for atrial fibrillation. The recovery rate of both atrial contractility is reported low in the atrial fibrillation associated with mitral valvular heart disease than that of loan atrial fibrillation. We performed the Cox-Maze procedure (Maze III) in three cases who suffered from non-mitral heart diseases associated with atrial fibrillation: A ruptured sinus of Valsalva aneurysm, a ventricular septal defect, and an aortic stenoinsufficiency. The Cox-Maze procedure was performed concomitantly with correction of the underlying heart disease. Conversion to sinus rhythm was achieved in all three patients, and both right and left atrial mechanical activities could be identified echocardiographically after three postoperative months.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.309-316
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• 1987

Since the first report of successful ligation of patent ductus arteriosus in 1939, it`s surgical intervention has become a routine and relatively safe procedure. During the past ten years from Aug. 1975 to Aug. 1985, 107 cases were operated on for a patent ductus arteriosus at the Department of thoracic and Cardiovascular Surgery, School of Medicine, Kyungpook National University. Clinical analysis of these cases was performed. Mean age at operation was 9.4 years, ranging from 20 months to 32 years. Sex ratio of female to male was 1.8;1. Most common symptoms were frequent respiratory infection, exertional dyspnea, and palpitation. Diagnosis was made by auscultation, 2 dimensional echocardiography, cardiac catheterization, and cineangiocardiography. A moderate to severe pulmonary hypertension was found in 42 cases [49.4%] in cardiac catheterization. Operative methods were multiple ligation of paten`. ductus arteriosus with or without Dacron or Teflon wrapping in 72 cases [68%], and division and suture in 34 cases [32%]. There were three operative deaths [2.8%]. The causes of death were hemorrhage from tearing of aorta, low cardiac output, and arrhythmia. All of these cases had moderate degree of pulmonary hypertension.

• Journal of Chest Surgery
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• v.28 no.4
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• pp.335-339
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• 1995

Secundum atrial septal defect occupies about 10 to 15% of congenital heart diseases, and the surgical accomplishment is outstanding, so that the operative mortality is getting near to zero percent. But, the methods of correction, direct closure versus patch closure are still controversial and there is no absolute method about it. Some surgeons prefer direct closure technique for its simplicity and lesser thrombogenicity but others, afraid of arrhythmia and suture detachment after closure of large defect, prefer patch closure. Usually most surgeons use direct suture technique in small and moderate sized defects and patch closure in large defects. In our hospital, 156 cases of isolated secundum atrial septal defect were closed directly by double continuous over and over suture using 5-0 polypropylene[prolene , regardless their sizes and the amounts of shunt flow. There were no operative mortality and no serious complications such as heart block, suture detachment and embolism.