• 제목/요약/키워드: QRS Complex

검색결과 130건 처리시간 0.033초

휴대형 심전계 장치의 RR 간격의 정확도 개선을 위한 보간법 개발 (Interpolation Technique to Improve the Accuracy of RR-interval in Portable ECG Device)

  • 이은미;홍주현;차은종;이태수
    • 대한의용생체공학회:의공학회지
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    • 제31권4호
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    • pp.316-320
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    • 2010
  • HRV(Heart rate variability) analysis parameter is widely used as an index to evaluate the autonomic nervous system and cardiac function. For reliable HRV analysis, we need to acquire the accurate ECG signals. Most of commercially available portable ECG devices have low sampling rate because of low power consumption and small size issues, which make it difficult to measure RR-interval accurately. This study is to improve the accuracy of RR-interval by developing R-wave interpolation technique, based on the morphological characteristics of the QRS complex. When the developed method was applied to ECG obtained at 200 Hz and the results were compared with 1000 Hz reference device, the error range decreased by 1.33 times in sitting and by 2.38 times in cycling exercise. Therefore, the proposed interpolation technique is thought to be useful to improve the accuracy of R-R interval in the portable ECG device with low sampling rate.

술후 심전도 변화가 예후에 미치는 영향에 관한 고찰 -선천성 심질환을 중심으로- (The prognostic implication of postoperative ECG changes in congenital heart surgery)

  • 정황규
    • Journal of Chest Surgery
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    • 제19권3호
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    • pp.363-373
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    • 1986
  • Even though the pathogenesis is still controversial, electrocardiographic changes after congenital open heart surgery depend on various etiologic factors. Author reviewed 261 cases of congenital open heart surgery patient experienced in the Dept. of Thoracic & Cardiovascular Surgery, Pusan National University Hospital, since July, 1981 to Sept., 1985. The results were summarized as followed: 1. The age distribution was from 3 to 29 years old with mean age 10.8 years. And the most frequent congenital heart defect we had done operation was VSD. 2. Preoperatively, the most frequent ECG finding was abnormal QRS complex and postoperatively the most frequent ECG change was arrhythmia. 3. The most frequent arrhythmia before operation was intraventricular conduction disturbance. 4. Right ventriculotomy incision produced the more frequent abnormal ECG changes postoperatively than right atriotomy or pulmonary arteriotomy. 5. According to the operative technique, outflow patch graft of TOF repair produced the highest frequency of ECG changes after operation, and in comparing simple and patch closure of VSD, the latter was higher frequency of ECG changes, in valvotomy and infundibulectomy of PS, the latter was higher too. 6. The common symptom and signs in abnormally ECG changed patients after operation were palpitation, dyspnea, congestive heart failure and murmur in this order., 7. The longer the time of CPB, the more number of abnormally ECG changed patients had been developed after operation. 8. The most of postoperative ECG changed patients recovered spontaneously or with only medication and were clinically insignificant. And the rest other minor group recovered with temporary pacing. Eight cases out of 261 [3.1%], these with abnormal QRS complex and arrhythmia couldn`t recover in spite of every effort and eventually succumbed.

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적응 디지털 필터 기반의 MRI Cardiac Gating을 위한 심전도 신호의 MR Gradient 잡음 최소화 방법 (Minimizing MR Gradient Artefacts on ECG Signals for Cardiac Gating based on an Adaptive Digital Filter)

  • 박호동;장봉렬;이경중
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.817-818
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    • 2006
  • In Magnetic Resonance Imaging(MRI), the QRS complex of ECG is used as a trigger signal for MRI scan. But, gradient and RF(radio frequency) artifacts which are caused to static and dynamic field in MRI scanner cause interference in the ECG. Also, the signal shape of theses artifacts can be similar to the QRS-complex, causing possible misinterpretation during patient monitoring and false gating of the MRI. In case of using general FIR or IIR band-pass filters for minimizing the artifacts, artifact-reduction-ratio is not excellent. So, an adaptive real-time digital filter is proposed for reduction of noise by gradient and RF(radio frequency) artifacts. The proposed filter for MRI-Gating is based on the noise-canceller with NLMS(Normalized Least Mean Square) algorithm. The reference signals of the adaptive noise canceller are a combination of the noisy three channel ECG signals. In conclusions, the proposed method showed the acceptable quality of ECG signal with sufficient SNR for gating the MRI and possibility of real time implementation.

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PVC Classification Algorithm Through Efficient R Wave Detection

  • Cho, Ik-Sung;Kwon, Hyeog-Soong
    • 센서학회지
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    • 제22권5호
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    • pp.338-345
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    • 2013
  • Premature ventricular contractions are the most common of all arrhythmias and may cause more serious situation like ventricular fibrillation and ventricular tachycardia in some patients. Therefore, the detection of this arrhythmia becomes crucial in the early diagnosis and the prevention of possible life threatening cardiac diseases. Most methods for detecting arrhythmia require pp interval, or the diversity of P wave morphology, but they are difficult to detect the p wave signal because of various noise types. Thus, it is necessary to use noise-free R wave. So, the new approach for the detection of PVC is presented based on the rhythm analysis and the beat matching in this paper. For this purpose, we removed baseline wandering of low frequency band and made summed signals that are composed of two high frequency bands including the frequency component of QRS complex using the wavelet filter. And then we designed R wave detection algorithm using the adaptive threshold and window through RR interval. Also, we developed algorithm to classify PVC using RR interval. The performance of R wave and PVC detection is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate average detection rate of 99.76%, sensitivity of 99.30% and specificity of 98.66%; accuracy respectively for R wave and PVC detection.

심전도 자동 진단 알고리즘 및 장치 구현(II) - 잡음 성분 평가 및 제거기 (An implementation of automated ECG interpretation algorithm and system(II) - Estimation and Eliminator of interference components)

  • 권혁제;공인욱;이상학;신건수;이명호
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1996년도 춘계학술대회
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    • pp.283-287
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    • 1996
  • This paper described the estimator and eliminator far three kinds of artifacts in electrocardiogram. The most efficient estimation of baseline drift could be obtain in the cubic spline interpolation method with the PQ and TP segment which are considered to be isoelectric, from the experimental results obtained from the applied 4 types of algorithms. The time loss and distortion could be avoided with the aid of detection criteria by checking if baseline drifts exist or not. The AIEF proposed in this paper was verified as having the best removal performance with less distortion in the QRS complex through the comparison of 5 proposed algorithms. furthermore, the AIEF are most suitable far the ECG analyzer which was only needed relatively short time data due to the fast conversion into the stable state. The proposed parabolic filter with 11 points width was identified as having the best performance for the elimination of muscle artifacts. Also we could obtain 99.7% detection accuracy of spike component and minimize the error identifying QRS complex as spike.

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심장질환진단을 위한 ECG파형의 특징추출 (Feature Extraction of ECG Signal for Heart Diseases Diagnoses)

  • 김현동;민철홍;김태선
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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    • pp.325-327
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    • 2004
  • ECG limb lead II signal widely used to diagnosis heart diseases and it is essential to detect ECG events (onsets, offsets and peaks of the QRS complex P wave and T wave) and extract them from ECG signal for heart diseases diagnoses. However, it is very difficult to develop standardized feature extraction formulas since ECG signals are varying on patients and disease types. In this paper, simple feature extraction method from normal and abnormal types of ECG signals is proposed. As a signal features, heart rate, PR interval, QRS interval, QT interval, interval between S wave and baseline, and T wave types are extracted. To show the validity of proposed method, Right Bundle Branch Block (RBBB), Left Bundle Branch Block (LBBB), Sinus Bradycardia, and Sinus Tachycardia data from MIT-BIH arrhythmia database are used for feature extraction and the extraction results showed higher extraction capability compare to conventional formula based extraction method.

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원격자동진단을 위한 ambulatory 심전도모니터링 시스템의 설계 (A Design of the Ambulatory ECG Monitoring System for the Remote Automatic Diagnosis)

  • 이경중
    • 대한의용생체공학회:의공학회지
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    • 제12권4호
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    • pp.277-284
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    • 1991
  • This study describes the ambulatory ECG monitoring system for the remote autom atic diagnosis. System: tlardware is based on one chip microcomputer(80c31) and its peripherals which consists of A/D, EPROM, RAM, LCD display and two preamplifiers, Power circuits, control logic circuits. A/D converted data were differentiated and low pass filtered. The detection of QRS complex and R point were accomplished by software algorithm based on adaptive threshold computed on low pass fi:leered signal. Rhythm analysis is performed by RR interval and average RR interval. The performance of QRS detection algorithm is evaluated by using MIT/BIH data base. Using this system, the trends of the arrythmia during the long term could be saved and displayed.

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정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) I. 표준지유도(標準肢誘導) (Studies on electrocardiogram of the normal Korean native cattle I. Standard limb leads)

  • 최인혁;정인성;김남수;서두석
    • 대한수의학회지
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    • 제33권4호
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    • pp.719-734
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    • 1993
  • The electrocardiographic(ECG) parameters on the standard limb leads in the normal Korean native cattle have been measured with a 3 channel Electrocardiograph built in a computed analysis. The study was conducted on the animals 98 heads of mean age of 17.7 months. Conduction parameters, waves, intervals and segments have been recorded. The recordings were analyzed as to shape and amplitude of the P and T waves and the components of the QRS complex. Heart rate was recorded by the Electrocardiogram which were a mean of $80.4{\pm}11.6beats/min$. And the younger had a higher heart rate than the older one. Average conduction times in the RP, the QRS complex and the QTc interval recorded $166.7{\pm}23.1msec.$, $79.7{\pm}8.8msec.$ and $395.5{\pm}30.4msec.$, in the P and T wave duration recorded $70.1{\pm}13.5msec.$ and $97.6{\pm}16.9msec.$, and in the PR and ST segment duration recorded $97.9{\pm}23.5msec.$ and $173.9{\pm}40.3msec.$, respectively. The wave forms in each lead observed various types. The amplitudes of wave type showed the highest frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of the positive type showed the frequency of 65.3%, 82.7% and 52.0% in leads I, II and III that were $103.1{\pm}47.8{\mu}V$, $115.2{\pm}37.3{\mu}V$ and $67.4{\pm}26.9{\mu}V$, and it showed the frequency of 54.1% and 85.7% in the leads aVL and aVF that were $63.7{\pm}23.0{\mu}V$, $88.0{\pm}83.6{\mu}V$, respectively. Average amplitude of the negative type showed the frequency of 78.6% in lead aVR which was $99.3{\pm}38.0{\mu}V$. 2. Average amplitude of the QRS complex were from $362.8{\pm}177.7{\mu}V$ to $532.8{\pm}253.9{\mu}V$(mean of $449.1{\pm}57.2{\mu}V$) that in all leads except lead I were manifested the Low-Voltage QRS complex(below 0.5mV). Average amplitudes of each wave type in the QRS complex aere $-50.2.4{\pm}258.2{\mu}V$ and $-428.6{\pm}195.1{\mu}V$ in the QS groups type that showed a frequency of 66.3%, 70.4% in the leads I and aVL, were $451.1{\pm}20.4.0{\mu}V$, $387.6{\pm}175.8{\mu}V$ and $299.3{\pm}146.5{\mu}V$ in the R groups type that showed a frequency of 48.0%, 53.1% and 34.7% in the leads III, aVR and aVF, and were $-307.5{\pm}180.3{\mu}V$, $201.4{\pm}77.2{\mu}V$ in the QR wave type which showed a frequency of 39.8% in lead II, respectively. 3. In T wave, amplitude of the positive type showed the frequency of 50.0%, 82.7%, 51.0% and 57.1% in leads II, III aVR and aVF which were $214.9{\pm}115.6{\mu}V$, $188.5{\pm}119.3{\mu}V$, $191.0{\pm}93.7{\mu}V$ and $165.7{\pm}91.9{\mu}V$, and the negative type showed a frequecny of 66.3% and 72.5% in leads I and aVL. that were $221.3{\pm}112.5{\mu}V$, $-173.6{\pm}86.7{\mu}V$, respectively. 4. Amplitude of ST segment in leads I, II and III were a mean of $-12.2{\pm}37.2{\mu}V$, $17.5{\pm}42.6{\mu}V$ and $28.3{\pm}40.4{\mu}V$, in leads aVR, aVL and aVF were $-3.9{\pm}32.5{\mu}V$, $-15.9{\pm}35.6{\mu}V$ and $26.2{\pm}37.5{\mu}V$, respectively.

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ECG 신호에서 단위패턴간 유사도분석을 이용한 부정맥 분류 알고리즘 (The Classification of Arrhythmia Using Similarity Analysis Between Unit Patterns at ECG Signal)

  • 배정현;임승주;김정주;박성대;김정도
    • 정보처리학회논문지D
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    • 제19D권1호
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    • pp.105-112
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    • 2012
  • 조기심실수축과 조기심방수축을 검출하기 위한 대부분의 알고리즘은 정확한 QRS complex, P파 및 T파의 측정을 필요로 한다. 이 논문에서, 우리는 복잡한 매개변수와 알고리즘을 사용하지 않으면서 조기심실수축과 조기심방수축을 검출하기 위한 새로운 알고리즘을 제안한다. 제안된 알고리즘은 대부분의 정상 ECG 파형 뿐만 아니라 개인적 특징과 개인적 차이에 의해 발생할 수 있는 비정상 파형에도 적용할 수 있는 넓은 적용성을 가지고 있다. 이러한 목적을 위해, ECG 파형을 각각의 단위 패턴으로 분리한 후, 정상 R-R 간격을 가지는 단위패턴만을 사용하여 기준단위패턴을 만든다. 그 후에, 기준단위 패턴과 각각의 단위패턴 사이에 패턴매칭을 위한 유사도 분석을 사용하여 조기심실수축과 조기심방수축을 검출한다.

실내 건강모니터링을 위한 Ad-hoc기반의 기능성 무선센서노드 평가 (Evaluation of functional wireless sensor node based Ad-hoc network for indoor healthcare monitoring)

  • 이대석;도경훈;이훈재
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 춘계학술대회
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    • pp.313-316
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    • 2009
  • 본 연구에서는 의료목적 무선 센서네트워크 환경에서 요구하는 데이터 전달의 신뢰성 향상을 위해 기능성 노드를 제안한다. 생체신호 모니터링을 위해 기존의 지속적인 생체신호 전송 시에 발생하는 데이터 손실을 줄이기 위해 비정상적인 QRS-complex 검출이 가능한 센서노드를 이용하여 Ad-hoc 네트워크 환경에서 비정상적인 QRS-comoplex 발생 시 데이터 전송함으로써 무선 센서네트워크 내에 발생되는 데이터량을 줄일 수 있었다. 본 연구에서 결과로 Ad-hoc 환경에서의 기능성 노드를 사용함으로 의료 목적을 위한 무선 센서네트워크에서 전체 패킷발생을 줄여서 센서노드의 전력소모를 크게 줄이고 시스템의 신뢰도를 크게 높이는 것으로 확인되었다.

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