• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.4
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• pp.201-207
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• 2001

This paper describes an automated detection algorithm of ST-T episodes using global curvature which can connect the isoelectric level in ECG and can eliminate not only the slope of ST segment, but also difference of the baseline and global curve. This above method of baseline correction is very faster than the classical baseline correction methods. The optimal values of parameters for baseline correction were found as the value having the highest detection rate of ST episode. The features as input of backpropagation Neural Network were extracted from the whole ST segment. The European ST-T database was used as training and test data. Finally, ST elevation, ST depression and normal ST were classified. The average ST episode sensitivity and predictivity were 85.42%, 80.29%, respectively. This result shows the high speed and reliability in ST episode detection. In conclusion, the proposed method showed the possibility in various applications for the Holter system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.38-46
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• 2012

Atrial fibrillation is needed to be detected at paroxysmal stage and to be treated. But, paroxysmal atrial fibrillation ECG is hardly obtained with 12-lead electrocardiographs but Holter systems. Presently, the averaged beat subtraction(ABS) method is solely used to estimate atrial fibrillatory waves even with somewhat large residual error. As an alternative, in this study, we suggested an ESAF(event-synchronous adaptive filter) based algorithm, in which the AF ECG was treated as a primary input and event-synchronous impulse train(ESIT) as a reference. And, ESIT was generated so to be synchronized with the ventricular activity by detecting QRS complex. We tested proposed algorithm with simulated AF ECGs and real AF ECGs. As results, even with low computational cost, this ESAF based algorithm showed better performance than the ABS method and comparable performance to algorithm based on PCA(principal component analysis) or SVD(singular value decomposition). We also proposed an expanded version of ESAF for some AF ECGs with multi-morphologic ventricular activities and this also showed reasonable performance. Ultimately, with Holter systems including our proposed algorithm, atrial activity signal can be precisely estimated in real-time so that it will be possible to calculate atrial fibrillatory rate and to evaluate the effect of anti-arrhythmic drugs.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.129-132
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• 2016

Ictal tachycardia and bradycardia are common arrhythmias; however, ictal sinus pause and asystole are rare. Ictal arrhythmia is mostly reported in adults with temporal lobe epilepsy. Recently, ictal arrhythmia was recognized as a major warning sign of sudden unexpected death in epilepsy. We present an interesting case of a child with ictal sinus pause and asystole. A 27-month-old girl was hospitalized due to 5 episodes of convulsions during the past 2 days. Results of routine electroencephalography (EEG) were normal, but she experienced brief generalized tonic seizure for 3 days. During video-monitored EEG and echocardiography (ECG), she showed multiple myoclonic seizures simultaneously or independently, as well as frequent sinus pauses. After treatment with valproic acid, myoclonus and generalized tonic seizures were well controlled and only 2 sinus pauses were seen on 24-hour Holter ECG monitoring. Sinus dysfunction should be recognized on EEG, and it can sometimes be treated successfully with only antiepileptic medication.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.17-23
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• 2011

In this paper, daily life stress monitoring system is proposed. The proposed wireless ECG module, reducing the noise and increasing the size of signal, amplification circuit was designed for. Using HRV(Heart Rate Variability), extracted by measuring R-wave, stress diagnostic algorithms to assess the stress of human emotion were developed. For monitoring the activities, the proposed system is consist of small rectangular size for portable and by simple measurement it is possible to measure at any time. Through experiments, the proposed approach to represent user's stress level can be confirmed. Through that, it can see appropriate structure to obtain R-wave for stress assess as well as high resemblance to the clinical electrocardiogram. In this paper, performed experiments was developed nonrestraint measuring and wearable wireless biometric scanner that is able to monitor the heart's electrical activity of everyday life.Using this, the algorithm system, that is able to assess stress index through time-domain and frequency-domain analysis of the front and the rear of performing stress load protocol, was developed,

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.512-515
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• 2001

The heifer electrocardiograph is a widely progressing research which is used in judgement to existence for a heart disease and analyzes electric potential changes of heart movement during continuous living of everyday after attaching to body portable holler recorder for twenty-four hours. In order to obtain electrocardiogram clearly, it must eliminate that 60Hz power line interference, baseline wandering, noise of muscle constriction. In holter electrocardiogram, the most big problem which is recorded signal of ECG(electrocardiogram) is a baseline wandering elimination, which is occurred by rhythm of respiration and muscle constriction of part from attaching to an electrode. Such baseline is roughly irregular wandering and shaking up and down therefore the part of baseline wandering elimination is very important because it is difficult of ECG diagnosis. In this study, it is stabilized baseline wandering in analog part as implementation f real-time signal processing digital filter so it is applicable to analyze patient's heart disease by way of design of baseline wandering elimination system.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.451-454
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• 1997

It has been reported that sudden cardiac death and ventricular tachycardia occur after treatment of tetralogy of fallot(TOF). It is regarded that ventricular arrythmia is the main source or the sudden cardiac death, but it is not verified. It is likely that TOF has effect on the heart rate variability because of the ventricular arrythmia. We study how complex and periodic heart rate dynamics change in the normal children (n=13) and TOF children (n=13) throughout 24 hours. We recorded 24-hour holter ECG, and segmented each ECG data into 1 hour length. We analyze each HR time series, and quantify the overall complexity of each HR time series by its correlation dimension. We also calculate the power spectrum of HR, and obtain low-frequency component (0.03-0.15Hz) and high-frequency component (0.15-0.4Hz). We compare the results between normal and TOF groups throughout 24 hours. TOF group have lower correlation dimension ($4.055{\pm}0.4134$ vs. $4.9310{\pm}0.2054$, p<0.05) than the normal group, even though there are no significant differences in the low($0.9864{\pm}0.5598$ vs. $1.5560{\pm}0.8325$, p<0.05) and high($1.1168{\pm}0.1.1448$ vs. $0.9271{\pm}0.6528$, p<0.05) frequency components. It can be concluded that HR time series of TOF group are more regular than that of normal group, and that correlation dimension reveals a nonlinear characteristics of HR time series which is not determined in the frequency domain.

• Journal of Yeungnam Medical Science
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• v.11 no.1
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• pp.181-185
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• 1994

Pacemaker malfunctions are secondary to alterations of the preset pacing rate, irregular pacing failure of sensing, failure of cardiac capture or depolarization, and various combinations of these events. A 76 years old male patient was admitted due to pacemaker malfunction. 2 years ago, he was diagnosed as complete atrioventricular block. And then bipolar permanent pacemaker was implanted. Since then syncopal attack developed repetitivly. 12 lead ECG and 24 hour holter moniter monitoring, revealed pacing and sensing failure, thus we converted bipolar system into unipolar system. Since then syncopal attack did not developed again.

• Clinical and Experimental Pediatrics
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• v.46 no.5
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• pp.490-494
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• 2003

Purpose : We'd like to determine the incidence of congenital heart disease and arrhythmia in elementary school children in Busan, and to provide adequate prevention and treatment. Methods : A total of 23,802(male 12,909, female 10,893) 1st grade elementary school children living in Busan were studied. All children were 7-8 years old. We obtained their medical history by questionnaire and checked elecrocardiography(ECG). Subsequent screening tests including a 2nd ECG, chest X-ray, phonocardiogram and CBC for the students who had abnormal findings at the first screening test. The third screening test was done for students who had cardiac murmurs or abnormal ECG findings in the second screening test by echocardiogram, treadmill test and 24-hour Holter monitoring. Results : Among 23,802 children participants, 605(2.54%) had abnormal ECG findings at the first screening test. Q wave abnormality(0.58%) was observed most frequently, and complete right bundle branch block(RBBB)(0.26%), sinus tachycardia(0.24%), right axis deviation(0.22%) and ventricular premature contraction(VPC)(0.21%) followed in order. Four hundred and twenty four children participated in the second ECG screening test. Two hundred and two children(47.6%) had an abnormality such as sinus tachycardia(18.8%), VPC(17.8%), or complete RBBB(17.3%). After completing the third examination including echocardiogram, we couldn't find the students with ventricular tachycardia (VT) or SVT at the third arrhythmia screening test. Conclusion : A high incidence of arrhythmia was found in the 1st grade elementary school children in Busan despite their healthy appearances, although fatal heart diseases were not noted. Early diagnosis, adequate preventative measures and treatment will prevent and decrease the frequency of emergent situations like syncope and sudden death.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.3
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• pp.61-69
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• 2015

This study presents a probabilistic knowledge discovery method to interpret heart rate variability (HRV) based on time and frequency domain indexes, extracted using discrete wavelet transform. The knowledge induction algorithm was composed of two phases: rule generation and rule estimation. Firstly, a rule generation converts numerical attributes to intervals using ROC curve analysis and constructs a reduced ruleset by comparing consistency degree between attribute-value pairs with different decision values. Then, we estimated three measures such as rule support, confidence, and coverage to a probabilistic interpretation for each rule. To show the effectiveness of proposed model, we evaluated the statistical discriminant power of five rules (3 for atrial fibrillation, 1 for normal sinus rhythm, and 1 for both atrial fibrillation and normal sinus rhythm) generated using a data (n=58) collected from 1 channel wireless holter electrocardiogram (ECG), i.e., HeartCall$^{(R)}$, U-Heart Inc. The experimental result showed the performance of approximately 0.93 (93%) in terms of accuracy, sensitivity, specificity, and AUC measures, respectively.

• The Journal of Internal Korean Medicine
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• v.27 no.3
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• pp.698-705
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• 2006

Objectives : This study was designed to investigate the effect of PC6 and SP4 on autonomic nerve system in healthy adults. Methods : 22 healthy adults were recruited and randomized into the study group or control group. The study group (real acupuncture group) was acupuncturcd on PC6 and SP4. The control group (sham acupuncture group) was acupunctured superficially near PC6 and SP4 but not the exact points. The subjects rested for 10 minutes, and were then acupunctured. After 15 minutes, acupuncture needles were removed and the subjects rested for another 15 minutes. Heart rate variability(HRV) was continuously measured during the study period by FM-150 (digital Holter ECG recorder). Results : In the real acupuncture group. LF(low frequency) significantly decreased during the acupuncture period(p<0.05). LF/HF ratio also had a significant decrease during acupuncture period and the decrease was maintained during the post-treatment period as compared with the pre-treatment period. In the sham acupuncture group. LF significantly increased during the acupuncture period but LF/HF ratio had no significant changes. Conclusions : The results suggest that acupuncture on PC6 and SP4 can increase parasympathetic activity and balance autonomic nervous system.