• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.91-95
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• 2001

In this study, we estimated the behavior of the diversity of physiological responses under varied physical environmental factors by measuring variations of heart rate variability (HRV), an index of activity of cardiac autonomic control. Seven healthy young male adults consented and participated in the study. The environmental conditions consisted of thermal, lighting, and acoustic conditions. Two components of HRV were measured. one was the low frequency (LF) component of HRV, which provided a quantitative index of the sympathetic and parasympathetic (vagal) activities controlling the heart rate (HR). The other component measured was the high frequency (HF) component, which provided an index of the vagal tone. The percent contribution of physical environmental factors to the variations in HRV indices were calculated by ANOVA. The contribution of physical environmental factors to the variations in HR was higher than the contribution of HF and LF. However, the contribution of these factors was lower than the contribution related with individual difference in all indices. This result showed that the individual diversity of physiological responses is not a negligible quantity.

• Journal of the Korean Home Economics Association
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• v.25 no.1
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• pp.51-58
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• 1987

This study was undertaken to investigate changes in blood pressure and heart rate in normal cats by administration of Korean native green tea. The chemical components of Korean native green tea which determined are water(2.2%), water extract(32.7%), vitamin C(480%), caffeine(2.6%), tannin(32.7%) and amino acid of water soluble content 5.8%. Effect on blood pressure in administration 100mg/kg, 300mg/kg, 500mg/kg of extract of green tea, the mean depressor response is 44.8$\pm$3.3mmHg, 60.5$\pm$3.6mmHg, and 65.0$\pm$3.3mmHg in normal cats. Effect on heart rate in administration 100mg/kg, 300mg/kg of extract of Korean native green tea, the mean decreased heart rate is 2.8$\pm$4.5 beats/min, 15.2$\pm$6.4beats/min and 19.1$\pm$4.0 beats/min.

• The Journal of Korean Medicine
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• v.21 no.2
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• pp.79-86
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• 2000

Objectives and Methods : In order to elucidate toxic mechanism of myocardial damage and protective effect of myrrha water extract against cytotoxic effect of xanthine oxidase/hypoxanthine(XO/HX), cardioprotective effect of myrrha water extract was examined by MTT assay, LDH (Lactate Dehydrogenase) activity and heart beating rate after cultured myocardial cells derived from neonatal mouse were treated with various concentration of XO/HX, a free radical. Results : XO/HX induced a decrease of cell viability, an increase in the amount of LDH, and a decrease of heart beating rate on cultured myocardial cells in a dose-dependent manner. In cardioprotective effect of myrrha water extract, it showed a decrease in the amount of LDH and an increase of heart beating rate on cultured myocardial cells damaged by XO/HX. Conclusions : From the above results, it is suggested that XO/HX showed toxic effect in cultured myocardial cells derived from neonatal mouse and that myrrha water extract is very effective in the prevention of XO/HX-induced cardiotoxicity.

• YAKHAK HOEJI
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• v.26 no.2
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• pp.105-110
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• 1982

The antihypertensive effect of clonidine administered concurrently with labetalol or metoprolol were studied with spontaneously hypertensive rats (SHR). The changes of heart rate were also observed in the same rats. Every drug was orally administered single dose after prechecking the systolic blood pressure and heart rate of SHR. The blood pressure of SHR in concurrently administered group was more significantly decreased than in alone administered group. The effective and stable decrease of blood pressure was maintained at the group of clonidine with labetalol (0.05+50mg/kg) for 9 hours. The group of clonidine with metoprolol (0.05+100mg/kg) manifested more marked decrease of blood pressure than the group of metoprolol (100mg/kg) alone for 9 hours. The diminishing effect of heart rate was enhanced in group of administering clonidine with labetalol, decreasing the dose of labetalol from 50mg/kg via 25mg/kg to 12.5mg/kg. On the other hand, in the group that clonidine was administered concurrently with metoprolol, the diminishing effect of heart rate was decreased with decreasing doses of metoprolol from 100mg/kg via 50mg/kg to 25mg/kg.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1240-1245
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• 2015

The purpose of this paper is to investigate the autonomic nervous system activity in various ambient temperatures. To evaluate autonomic function, we use the frequency domain analysis of heart rate variability such as FFT(fast fourier transformation), AR(Auto-Regressive) model and Lomb-Scargle peridogram. HRV(heart rate variability) is calculated by using ECG recorded from 3 different temperature room which temperature is controlled in 18℃(low), 25℃(mid) and 38℃(high), respectively. Totally 22 subjects were participated in the experiment. In the results, the most significant autonomic changes caused by temperature load were found in the HF(high frequency) component of FFT and AR model. And the HF power is decreased by increasing temperature. Significance level was increased by increasing the difference of temperatures.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.4
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• pp.290-295
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• 2016

This paper proposes a new method for the automatic detection of atrial fibrillation (AF), using Markov regime switching GARCH (1, 1) model. The proposed method is based on the observation that variability patterns of heart rate intervals during AF significantly differ from regular patterns. The proposed method captures the different patterns of heart rate intervals between two regimes : normal and AF states. We test the proposed method using Massachusetts Institute of Technology-Beth Israel Hospital (MIT-BIH) atrial fibrillation database, and demonstrate the effectiveness of the proposed method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.241-244
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• 2009

We studied the optimization method of sensing part for measuring heart rate in wrist. In order to know optimum structure of sensing part, we measured the heart rate signal by changing the shape and size of sensor pad structure and the thickness of silicon. The shapes of structure using in experiment are Empty, Rectangle, Embossing, Length, Width. We were compared the amplitude of output signal about each shape when thickness of silicon pad is increasing from 0 to 7 mm by 1 mm.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.197-202
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• 2010

The purpose of this study was to examine differences between male and female in heart rate due to 93% oxygen administration of the three levels (1L/min, 3L/min, and 5L/min). Ten healthy male (25.0$\pm$1.8years) and ten female (23.7$\pm$1.9years) college students were selected as the subjects for this study. The experiment consisted of three runs, i.e., the three levels of 93% oxygen administration, respectively. The each run consisted of three phases, i.e., Rest 1 (5min), Hyperoxia (10min), and Rest 2 (5min). Heart rate was measured throughout the three phases. Heart rate was decreased during hyperoxia compared to Rest 1 and 2. By increasing the supply rate of highly concentrated oxygen, ${\Delta}1$ (decreasing rate of heart rate during hyperoxia compared to Rest 1) was increased. And ${\Delta}2$ (decreasing rate of heart rate during hyperoxia compared to Rest 2) of male was lower than female, regardless of supply rate.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.3
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• pp.90-96
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• 2004

The objective of this study was to develop a model for safe work load based on a physiological model of metabolic energy of manual material handling tasks. Fifteen male subjects voluntarily participated in this study. Lifting activities with four different weights, 0, 8, 16, 24kg, and four different working frequencies (2, 5, 8, 11 lifts/min) for a lifting range from floor to the knuckle height of 76cm were considered. Oxygen consumption rates and heart rates were measured during the performance of sixteen different lifting activities. Simplified predictive equations for estimating the oxygen consumption rate and the heart rate were developed. The oxygen consumption rate and the heart rate could be expressed as a function of task variables; frequency and the weight of the load, and a personal variable, body weight, and their interactions. The coefficients of determination ($r^2$) of the model were 0.9777 and 0.9784, respectively, for the oxygen consumption rate and the heart rate. The model of oxygen consumption rate was modified to estimate the work load for the given oxygen consumption rate. The overall absolute percent errors of the validation of this equation for work load with the original data set was 39.03%. The overall absolute percent errors were much larger than this for the two models based on the US population. The models for the oxygen consumption rate and for the work load developed in this study work better than the two models based on the US population. However, without considering the biomechanical approach, the developed model for the work load and the two US models are not recommended to estimate the work loads for low frequent lifting activities.

• Journal of Chest Surgery
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• v.19 no.4
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• pp.672-677
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• 1986

From April, 1984 to August, 1986, 214 cases of cardiovascular surgeries had been performed at Yeungnam University Hospital consisting 158 open heart surgeries and 56 non-open heart surgeries. The leading cardiac anomaly of open heart surgeries was ventricular septal defect which was 43% of congenital heart diseases, and most of remaining non-open heart surgeries were ligating patent ductus arteriosus. We had observed 33 postoperative complications such as wound problems, transient arrhythmia, postpericardiotomy syndrome, bleeding requiring reoperation and so on. 3 cases of surgical mortality were present [2 in congenital heart diseases and 1 in acquired heart disease], which resulting 1.9% of surgical mortality rate in the open heart surgeries.