• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.437-444
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• 2016

Most methods for detecting arrhythmia require pp interval, diversity of P wave morphology, but it is difficult to detect the p wave signal because of various noise types. Therefore it is necessary to use noise-free R wave. In this paper, we propose algorithm for premature contraction arrhythmia classification through ECG pattern analysis and template threshold. For this purpose, we detected R wave through the preprocessing method using morphological filter, subtractive operation method. Also, we developed algorithm to classify premature contraction wave pattern using weighted average, premature ventricular contraction(PVC) and atrial premature contraction(APC) through template threshold for R wave amplitude. The performance of R wave detection, PVC classification is evaluated by using 6 record of MIT-BIH arrhythmia database that included over 30 PVC and APC. The achieved scores indicate the average of 99.77% in R wave detection and the rate of 94.91%, 95.76% in PVC and APC classification.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.669-672
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• 2017

최근 한국인의 주요 사망원인 중 하나로 부정맥이 부각되고 있다. 심방조기수축(PAC:Premature Atrial Contraction)은 심방이 동방결절의 명령이 있기 전에 수축해 버리는 것이다. 심방조기수축은 일시적으로 유발하였다 사라지곤 할 수 있기 때문에 심한 증상이 없다면 생명에 위협을 가하진 않지만 반대의 경우에는 위험할 수 있다. 따라서 비정상적인 심장 박동이 발생하면 이를 검출하여 조기에 부정맥을 진단할 수 있는 방법이 필요하다. 이를 위해 대상의 ECG 신호로부터 QRS패턴에 해당하는 특징들을 추출하였고 특징들을 이용하여 심방조기수축 파형을 분류한다. 오류 역전파 기반으로 특징들을 훈련하며 가중치와 바이어스값을 구한뒤 이를 이용하여 정상파형과 심방조기수축 파형을 분류한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.2
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• pp.15-21
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• 2009

This paper proposes a novel algorithm to assess the abnormal heart beats such as PVC (Premature Ventricular Contraction) and its subsequent RUNs. Our Arrhythmic detection scheme is based on only the R-R Interval features extracted from ECG waveforms and MIT-BIH arrhythmia database is evaluated to validate the efficiency of our algorithm in terms of sensitivity, specificity, FPR(%) and FNR(%).

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.472-473
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• 2008

심실조기수축(PVC: Premature Ventricular Contraction)은 성인에게서 가장 흔하게 발생되는 심장 부정맥 증상 중의 하나이다. 심실조기수축 부정맥이 자주 발현되는 사람의 경우 관상 동맥질환, 고혈압 등의 심혈관계 질환이 진행되고 있을 가능성이 많고, 심실빈맥이나 심실세동으로 전이되는 경우 심정지 등을 유발하여 사망에 이르기 때문에 지속적으로 관찰이 필요한 증상이다. 따라서 본 연구에서는 R-R 간격 정보를 이용하여 심실조기수축 부정맥 증상을 실시간으로 검출할 수 있는 신호처리 알고리즘을 구현하고자 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1399-1402
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• 2011

본 논문에서는 조기 심실 수축과 조기 심방 수축을 검출함에 있어 정밀한 QRS 구간의 폭, 정확한 P파와 T파의 크기 및 위치를 크게 요구하지 않고, 데이터의 가공과 복잡한 알고리즘의 사용에 의해 발생하는 ECG 데이터의 변형과 손실을 최소화할 수 있으며, 또한 개인차 때문에 발생할 수 있는 오류를 최소화하기 위한 알고리즘을 제안한다. 이를 위해 ECG 신호를 각각의 단위 파형으로 분리한 후, 정상 R-R 간격을 가지는 파형을 기준으로 기준파형을 만들어, 각 파형과 기준파형사이의 패턴 대조 및 유사도 분석을 통해 조기 심실수축과 조기심방수축을 검출할 수 있도록 하였다.

• The KIPS Transactions:PartD
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• v.19D no.1
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• pp.105-112
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• 2012

Most methods for detecting PVC and APC require the measurement of accurate QRS complex, P wave and T wave. In this study, we propose new algorithm for detecting PVC and APC without using complex parameter and algorithms. Proposed algorithm have wide applicability to abnormal waveform by personal distinction and difference as well as all sorts of normal waveform on ECG. To achieve this, we separate ECG signal into each unit patterns and made a standard unit pattern by just using unit patterns which have normal R-R internal. After that, we detect PVC and APC by using similarity analysis for pattern matching between standard unit pattern and each unit patterns.

• Journal of the Korea Concrete Institute
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• v.13 no.4
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• pp.362-370
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• 2001

The internal or external restraint of thermal and dry shrinkage movements could thus generate tensile stresses in concrete pavement for early traffic opening. Restrained shrinkage and thermal stresses could produce microcracks in concrete which increase its permeability and accelerate its long-term deterioration under weathering and load effects. Fiber reinforced concrete is an effective approach to the control of microcrack and crack development under tensile stresses. This study aims at evaluation of the durability of high early strength concrete for early traffic opening and increase of service life. Three different types of regulated-set cement which recently has been used much in Korea were adopted. Fibers were added and their mixtures were compared with plain high early strength concrete mixture. The use of fibers increased durability performance of high early strength concrete using regulated-set cement than the corresponding plain mixtures.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.355-356
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• 2013

심장의 활동을 전기적 변위로 표현되는 심전도 신호는 심장병 진단에 중요한 임상적 파라미터들을 제공한다. 특히 심전도 신호에서 P, QRS Complex,, T 특징점들로 대표되는 파형 변곡점들의 시간상 위치와 크기 및 형태학적 모양은 심장의 이상 리듬을 나타내는 부정맥여부를 검출하는데 핵심적인 역할을 한다. 본 연구에서는 특히 QRS complex 구간에 대한 첨도치의 연산 해석을 통하여 정상적인 심전도 리듬과 심실조기수축 부정맥 리듬을 구분하는 방법을 제시하고 또한 스마트폰을 기반으로 하는 심전도 모니터링 시스템에 적용하고자 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.296-302
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• 2016

Studies aimed at reducing the occurrence of cracks by the shrinkage of concrete are in demand because the repair and reinforcement for cracks caused by declining concrete durability costs the user to maintain the concrete structure. In particular, in underground power facilities for power transmission, the cost is a heavy burden to repair and reinforce. For this reason, underground power facilities demanded effective methods for crack reduction at the engineering design step. This study, as a part of the development of shrinkage reducing agent for low shrinkage concrete on underground power facilities, investigated TEA to complement the shrinkage reducing agent to improve the early strength of concrete. In the case of TEA 3% as a shrinkage reducing agent, the early strength was improved significantly, and the shrinkage reducing effect was excellent. In addition, TEA 3.0 % and the shrinkage reducing agent 2.0 % showed excellent shrinkage property and compressive strength. On the other hand, more study of shrinkage reducing materials, including performance reviews on the shrinkage reducing materials with variable factors and type of materials, will be needed to generalize these results.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.42-49
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• 1999

Background: In patients with chronic obstructive pulmonary disease(COPD). it is well known that hypoxemia increases the frequency of VPB, which is associated with the poor prognosis such as sudden death. The aim of this study is to evaluate the effect of short and long-term low flow oxygen therapy on the development of VPBs in patients with COPD by correcting the hypoxemia. Method: In 19 patients with COPD, oxygen saturation and VPB's were monitored by pulse oxymeter and 24-hour Holter EKG, with room air and oxygen saturation and VPB's were monitored on the 1st and on the 8th day during oxygen therapy with nasal prong (2L/min). Results : The arterial oxygen saturation was significantly higher on the 1st day of oxygen therapy compared with breathing room air, and was also higher on the 8th day of oxygen therapy than on the 1st day. We found that there was significant correlation between the lowest value of the arterial oxygen saturation and the mean value of the arterial oxygen saturation. The number of VPB's per hour was significantly lower on the 1st day of oxygen therapy compared with breathing room air, and also lower on the 8th day of oxygen therapy than on the 1st day. Our results showed positive correlation between the decrease in the frequency of VPB's and the increase in the lowest arterial oxygen saturation, even though correlation was not significant(p=0.056). Conclusion: With oxygen therapy, the arterial oxygen saturation was increased and the number of VPB's was decreased. Long-term oxygen therapy more than 7days, would be helpful to decrease the number of VPB' s in patients with COPD.