• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.421-425
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• 1989

This paper present a algorithm for determination of the frontal QRS axis. Determination of electrical QRS axis helps In the differential diagnosis of wide QRS tachycardia and of hemiblock and In the localization of an accessory pathway. At first detecting R-point data and S-point data and two data is sumed and this data is determind such as positive or negative. Reference data is calculated by 9-point derivertives that is less affected by noise. Secondly, using data of lead2 calculate a morphology, this value is threshold for executing determination algorithm. This process is main body of this algorithm. As this algorithm have a six pattern of the axis that coded by minnesota ending method, the axis is determined more precisely than any other algorithm using 3 leads and affirm a relation of a axis and hemiblock and tachycardia.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.265-268
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• 2002

For accurate interpretation, ECG signal is measured by using 12 leads method. We look shape of Measured ECG signal and decide whether interpretation is accurate or not. In this paper, we propose new effective fuzzy decision system which uses fuzzy rules and membership functions for more accurate of ECG wave. We used PR interval, QRS interval and QRS axis as conditional variables for designing fuzzy rules. And decision rule of conclusion variable is determined by (sinus rhythm), (sinus rhythm+left deviation), (sinus rhythm+right deviation) and (sinus rhythm+negative axis). Experimental results showed our system made numerically easy decision possible and had advantage of simple design method.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.241-250
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• 1987

We scrutinized the preoperative electrocardiographic and hemodynamic findings in adult atrial septal defects older than 15 years, and then followed up the postoperative electrocardiographic changes sequentially. In preoperative electrocardiographs, the mean PR interval [0.17 sec] was prolonged than normal adults [M;0.13,F;0.15], and the mean QRS axis [93.1*] was deviated to rightward than normal [M;63.7*,F;64.4*], and 122 cases of all 159 patients [77.8%] were in RAD quadrant. The QRS morphology was classified into three groups; a] crista supraventricularis hypertrophy, 25 cases, b] right ventricular outflow tract hypertrophy, 89 cases, c] right ventricular hypertrophy, 44 cases, and normal rs pattern, 1 case. Comparing the QP/QS, Pp/Ps, Rp/Rs in these three groups, Qp/Qs increased a] 2.65 to b] 2.97 and decreased b] 2.97 to c] 2.55, Pp/Ps increased a] 0.27 to b] 0.35 to c] 0.44, and Rp/Rs increased a] 0.1 to b] 0.14 to c] 0.2. In comparing the atrial fibrillation with sinus rhythm, the patient`s mean age was increased [26.4 to 45.7], the mean Qp/Qs was decreased [2.97 to 2.7], the mean Pp/Ps was increased [0.35 to 0.46], the mean Rp/Rs increased [0.14 to 0.2], and the QRS morphology was RVOT hypertrophy;7 cases, RVH;2 cases in all 11 cases. Therefore, the atrial fibrillation was appeared in progressed status. Increasing the mean pulmonary arterial pressure, size of the R` wave in Vl lead increased, and the QRS morphology tended to become severe patterns. Postoperatively, the PR interval shortened and QRS axis tended to normal axis quadrant, and size of R` wave decreased sequentially, atrial fibrillation disappeared in 4 cases. Conclusively, by use of the conventional surface electrocardiography, we could anticipate the hemodynamic changes and the prognosis at outpatient department.

• Journal of Life Science
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• v.20 no.1
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• pp.71-76
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• 2010

The purpose of this study was to investigate the changes of long term ECG response in a company with middle-aged male employees. Subjects were 60 men who were 40~55 years old. We enrolled 30 exercise group subjects into a 3-year exercise program. In measurement index, body composition was measured by % body fat and BMI. Exercise stress test analyses were measured using ST/HR slope and QRS vector. Statistical analysis was performed using analysis of repeated ANOVA. Results of this study were as follows: In ST/HR slope, the control group showed symptoms of ischemia after nine minutes of exercise. In the rest frontal axis of the QRS vector, the control group had a tendency towards right axis deviation. In the rest horizontal amplitude of the QRS vector, the control group had a tendency to show a significant decrease, but it was increased significantly in the exercise group. These findings suggest that inactive company workers was showed a decrease of exercise capacity, early diagnosis exercise-induced ST depression, and prolonged deviation of QRS vector, but that cardiac function could be elevated in active middle aged men through regular exercise program participation.

• The Korean Journal of Physiology
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• v.16 no.1
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• pp.41-50
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• 1982

The effects of $NaHCO_3$ on the electrocardiogram of rats were studied in the induced hyperkalemia. The subjects were divided into 4 groups: the group 1 was normal control and the data on this normal control had teen obtained from the following three groups before administration of KCl or $NaHCO_3$, the group 2 (KCl) was administered 40 ml per kg body weight of the 10 per cent KCl solution, the group 3 $(NaHCO_3)$ was administered 40 ml per kg body weight of the 10 per cent $NaHCO_3$ solution, and the group 4 $(KCl+NaHCO_3)$ was received 10 per cent KCl, which was followed by administration of 10 per cent $NaHCO_3$ at one and half hours later. In KCl, the heart rate was decreased rapidly, and then maintained its level, later rapid decreasing heart rate was followed by the cardiac stand still. The mean electrical axis of QRS complex became progressively deviated to the left. The amplitude of T wave was increased transiently but was not changed thereafter. There was prolongation of the P-Q interval and the Q-T interval at the beginning and then they were shortened. In $NaHCO_3$, the heart rate was decreased rapidly at the beginning, later showed a tendency of recovery. The mean electrical axis of QRS was not changed initially, but later became deviated to the left. The amplitude of T wave was not changed. There was prolongation of the P-Q interval and the Q-T interval at the beginning and then they were shortened. In $KCl+NaHCO_3$, there were a tendency of recovery of both the amplitude of the T wave and the electrical axis of the QRS complex after administration of $NaHCO_3$ but the heart rate was not recovered. There was prolonged P-Q interval, but the Q-T interval was relatively unchanged.

• Journal of Life Science
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• v.20 no.5
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• pp.723-728
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• 2010

The effect of abdominal respiration on electrocardiogram readings was examined using a 12-lead ECG in healthy young adults. Ten males and ten females without any cardiac and/or pulmonary problems participated in this study. ECG readings during periods of abdominal respiration and thoracic respiration were compared using a paired t-test. Results showed that the PR interval was longer in males compared to females during the period of abdominal respiration (p<0.05). There were no differences in amplitudes of the P, R, T waves, QTc, and degree of P axis between abdominal respiration and thoracic respiration in both male and female subjects. However, degrees of QRS axis in male subjects (p<0.05) and T axis (p<0.05) in female subjects were increased during the abdominal respiration. Therefore, abdominal respiration may cause positive electrical axis changes in the depolarization and relaxing re-polarization of the ventricles.

• Journal of Preventive Medicine and Public Health
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• v.4 no.1
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• pp.1-18
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• 1971

Eleven nonathletes and eleven athletes were exercised on a standardised Harvard step test, and the average rate of change in QRS amplitude in lead III of the electocardiogram associated with heart rotation and the average change in rate of heart beat were observed. 1. After the Harvard step exercise, the average rate of change in QRS amplitude in lead III of both groups increased. This was due to the clockwise rotation of the heart and was associated with respiratory movement. The diaphragm was inferred to remain for a while in a relatively more inspiratory position. 2. After the Halved step exercise, a high correlation between the recovery of the average rate of change in QRS amplitude in lead III and the average change in rate of heart beat was observed in the athletic group. 3. In the nonathletic group there was no significant correlation between the average rate of QRS amplitude change and the average rate of change of heart beat. 4. Athletes were assumed to be trained to ventilate quickly at their maximum ability, using deep descending movements of the diaphragm and other respiratory musclature. Consequently, the average in rate of heart beat also recovered quickly. 5. Nonathletes were inferred not to have been trained to adjust quickly to ventilate so efficiently with their diaphragm movement and other respiratory musculature, and are characterised by their longer time to complete recovery.

• The Korean Journal of Physiology
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• v.18 no.1
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• pp.51-65
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• 1984

In an effort to elucidate the effect of physical training on the electrocardiographic amplitudes, QRS vector, axis and QRS vector amplitude, electrocardiograms were recorded before and 1, 5 and 10 minutes after 3 minute rebounder exercise in 23 healthy male students aged between 18 and 21 years in two groups of athletes and non-athletes. ECG amplitudes were measured from lead I, $V_1$ and $V_5$ and axis and amplitudes of QRS vectors were measured from lead I and III in frontal plane, from lead $V_2$ and lead $V_6$ in horizontal plane. The results obtained are summarized as follows. ECG amplitudes: The R wave amplitude was $23.38{\pm}1.14\;mm$ in athletes which was higher than $17.91{\pm}2.00\;mm$ in non-athletes. After exercise, the difference in two groups remained significant throughout the recovery period. The S wave amplitude was increased significantly, and the T wave amplitude was decreased in both groups after exercise. The P wave amplitude was increased in both groups after exercise, and it was lower in athletes than in non-athletes. The PQ segment amplitude was zero in athletes but negative in non-athletes than in the resting state. The J point amplitude was positive in resting state and was negative after exercise in both groups. J+0.08 sec point amplitude was also lowered after exercise, and it was higher in athletes than in non-athletes. Therefore the whole ST segment was proved to be decreased after exercise. The summated amplitude of R in $V_5$ plus S in $V_1$ was $38.74{\pm}2.71\;mm$ in athletes which was higher than $32.82{\pm}2.90\;mm$ in non-athletes. After exercise, it was also significantly higher in athletes than in non-athletes. Axis of QRS vector: In frontal plane, axis of QRS vector was $62.7{\pm}7.36^{\circ}$ in athletes, it showed no significant difference between the two groups. In horizontal plane, axis of QRS vector was $-23.5{\pm}7.2^{\circ}$ in athletes which was significantly higher than $-38.8{\pm}8.2^{\circ}$ in non-athletes. After exercise, it was significantly higher than the resting state in both groups. Amplitude of QRS vector : In frontal plane, amplitude of QRS vector was $13.86{\pm}1.44\;mm$ in athletes which was significantly higher than $9.62{\pm}0.97\;mm$ in non-athletes. After exercise, it was also significantly higher in athletes than in non-athletes. In horizontal plane, amplitude of QRS vector was $19.82{\pm}2.10\;mm$ in athletes which was significantly higher than $16.90{\pm}1.39\;mm$ in non-athletes. After exercise, it was also significantly higher in athletes than in non-athletes. From the above, these results indicate that R wave amplitude in athletes was significantly higher than in non-athletes before and after exercise, and that the summated amplitude of R in $V_5$ plus S in $V_1$ in athletes was also $38.74{\pm}2.71\;mm$ suggesting a left ventricular hypertrophy We should note that the PQ segment and ST segment amplitude were higher in athletes than in non-athletes, and they were decreased with exercise in both groups. In particular, the fact that amplitudes of QRS vector in frontal plane or in horizontal plane were significantly greater in athletes than in non-athletes may be an index in evaluating athletes.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.697-700
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• 1988

This paper describes the design of a hardware system for ECG feature extraction based on pipeline processor consisting of three computers. ECG data is acquisited by 12 bit A/D converter with hardware QRS triggred detector. Four diagnostic parameters-heart, axis, and ST axis, and ST segment are used for the classification and the diagnosis of arrhythmia. The functions of the main CPU were distributed and processed with three microcomputers. Therefore the effective data process and the real time process using microcomputer can be obtained. The interconnection structure consisting of two common memory units is designed to decrease the delay time caused by data transfer between processors and designed by which the delay time can be taken 1% of one clock period.

• Journal of Korea Multimedia Society
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• v.19 no.5
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• pp.818-825
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• 2016

The existing R-peak detection research suggests improving the distortion of the signal such as baseline variations in ECG signals by using preprocessing techniques such as a bandpass filtering. However, preprocessing can introduce another distortion, as it can generate a false detection in the R-wave detection. In this paper, we propose an R-peak detection algorithm in ECG signal, based on primitive signal in order to detect reliably an R-peak in baseline variation. First, the proposed algorithm decides the primitive signal to represent the QRS complex in ECG signal, and by scaling the time axis and voltage axis, extracts multiple primitive signals. Second, the algorithm detects the candidates of the R-peak using the value of the voltage. Third, the algorithm measures the similarity between multiple primitive signals and the R-peak candidates. Finally, the algorithm detects the R-peak using the mean and the standard deviation of similarity. Throughout the experiment, we confirmed that the algorithm detected reliably a QRS group similar to multiple primitive signals. Specifically, the algorithm can achieve an R-peak detection rate greater than an average rate of 99.9%, based on eight records of MIT-BIH ADB used in this experiment.