• Child Health Nursing Research
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• 제6권1호
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• pp.32-50
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• 2000

A descriptive exploratory design was used in this study to evaluate the effects of sponge bathing on physiological(heart rate, heart period, vagal tone, oxygen saturation, respiration) and behavioral responses in newly born 40 preterm infants from intensive care unit of S University Hospital in Seoul. Data has been collected from October, 1997 to March, 1999. The infants were between 27-33 weeks gestational age at birth, and were free of congenital defects. The subjects entered the protocol when they were medically stable (determined by initiation of feeding and discontinuation of all respiratory support) but still receiving neonatal intensive care. The infants' physiologic parameters were recorded a 10 - minute before, during, and after bathing. Continuous heart rate data were recorded on a notebook computer from the infant's EKG monitor. The data were digitized off-line on software(developed by Lee and Chang in Wavelet program) which detected the peak of the R wave for each heart beat and quantified sequential R-R intervals in msec(i.e. heart periods). Heart period data were edited to remove movement artifact. Heart period data were quantified as : 1) mean heart period; 2) vagal tone. Vagal tone was quantitfied with a noninvasive measure developed by Porges(1985) in Mxedit software. To determine behavioral status, tools were developed by Scafidi et al(1990) were used. Collected data were analyzed with the SPSS program using paried t-test, ANOVA, and Pearson correlation. The result were as follow. 1. The results of the ANOVAs indicated that vagal tone were signifcantly lower during bathing than baseline and post-bathing. There were significant differences in heart period and heart rate levels across the bathing. But the mean oxygen saturations and respirations were no differences. Also, there were no significant differences on behavioral sign, motor activity, behavioral distress, weight changes, morbidity, and hospitalization period. 2. To evaluate the relation between vagal tone and subsequent parameters, the two groups (the high group had 19 subjects and low group had 21subjects) were divided by the mean baseline vagal tone. Vagal tone measured prior to bathing were significantly associated with respiration before bathing, vagal tone during bathing, and the magnitude of change in both vagal tone. But, other subsequent reactivities were no differences in two groups. 3. Correlations were also calculated between vagal tone and the subsequent physiological reactivities from baseline through after- bathing. Correlations were significant between baseline vagal tone and baseline heart rate, between baseline vagal tone and baseline heart period, between baseline vagal tone and oxygen saturation after bathing. In summary, the bathing in this study showed a stressful stimulus on premature infants through there was significance in the physiological parameters. In addition, our study represents the documentation that vagal tone reactivity in response to clearly defined external stimulation provides an index of infant's status.

• 동의신경정신과학회지
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• 제20권4호
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• pp.127-135
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• 2009

Objectives : This study was conducted to assess the effect of Chunwangbosim-dan(CB) on the autonomic nervous system by using heart rate variability measurement. Methods : The eligible subjects were composed of the healthy female group of ages 25 to 30 years. They were divided into two groups, the CB group(n=16) and the control group(n=16). We measured the heart rate variability respectively for 3 times at 14:00, 16:00, and 17:00. In the CB group, subjects were administered CB at 15:00. For the measurement values, Mean Heart Rate and SDNN(standard deviation of the NN intervals) were used as time domain analysis, and HF(high frequency), LF(low frequency), and LF / HF ratio were used as frequency domain analysis. Results : The degree of LF changes in the CB group was significantly lower than control group at 1 hour after administration. Conclusions : We suggest that Chunwangbosim-dan may be useful for stabilization of the autonomic nervous system by controlling sympathetic nerve in healthy people.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.651-661
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• 2021

This study aimed to investigate whether breed, sex, and age affected temperament differently (more or less neophobic) in mature horses during a novel object test. The study included Jeju crossbred (n = 12, age = 9.42 ± 4.57 y), Thoroughbred (n = 15, age = 10.73 ± 3.09 y), and Warmblood horses (n = 12, age = 13.08 ± 3.55 y) with the females (n = 22, age = 11.36 ± 4.24 y) and geldings (n = 17, age = 10.65 ± 3.66 y). Jeju crossbreds (Jeju horse × Thoroughbred) are valuable considering their popular usage in Korea, but limited studies have explored temperament of Jeju crossbred horses. A trained experimenter touched the left side of the neck with a white plastic bag (novel object). The test ended when the horse stopped escape response and heart rate (HR) dropped to baseline. Behavioral score and escape duration were measured as behavioral variables. Multiple variables related to HR and heart rate variability (HRV) were measured to reflect emotional state. These included basal HR (BHR), maximum HR (MHR), delay to reach maximum heart rate (Time to MHR), standard deviation of beat-to-beat intervals (SDNN), root mean square of successive differences (RMSSD), and ratio of low to high frequency components of a continuous series of heartbeats (LF/HF). Statistics revealed that Thoroughbreds had significantly higher behavioral scores, and lower RMSSD than Jeju crossbreds (p < 0.05), suggesting greater excitement and fear to the novel object in Thoroughbreds. None of the behavioral or cardiac parameters exhibited sex differences (p < 0.05). Age was negatively correlated with SDNN and RMSSD (p < 0.05), indicating that older horses felt more anxiety to the novelty than younger horses. Thoroughbreds and females had distinct correlations between behavioral and HRV variables in comparison with other groups (p < 0.05), implying that escape duration might be a good indicator of stress, especially in these two groups. These results are expected to improve equine welfare, safety and utility, by providing insights into the temperament of particular horse groups, to better match reactivity levels with specific functions.

• 대한한의학회지
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• 제42권2호
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• pp.50-61
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• 2021

Objectives: The object of this study was to examine whether there was a significant difference between morning and afternoon in heart rate variability(HRV) in healthy Korean adults. In addition, the correlation between the characteristics of the subjects and the test results was analyzed. Methods: From January 8, 2021 to January 29, 2021, twenty healthy subjects received short-term HRV test once in the morning(6:00~12:00) and twice in the afternoon(12:00~18:00). We used IBM SPSS Statistics 27 to test for statistical significance. Results: The mean heart rate and PSI decreased significantly and SDNN increased significantly in the morning compared to the afternoon. There was no significant difference except RMSSD in HRV conducted at 2 hours intervals in the afternoon. Age had a significant difference in SDNN and TP, and exercise in average heart rate. Age, weekly exercise frequency, and monthly drinking frequency showed significant correlations with HRV indicators. As a result of multiple regression analysis, monthly drinking frequency was a variable that had a significant influence on TP. Conclusions: The results of the tests performed with short interval were relatively consistent, and when comparing the results of the afternoon and the next morning, there were significant differences in several indicators. In the future, the number of HRV measurements should be increased and a larger-scale follow-up study including more subjects will be needed.

• 감성과학
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• 제18권3호
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• pp.63-70
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• 2015

본 연구는 1/f fluctuation의 ${\alpha}$기울기 따라 구성된 사운드를 들었을 때 감정 스트레스 업무에 종사하고 있는 피험자들의 심박 변화를 확인하고자 하였다. 기존의 연구에서는 주로 사용자의 심리상태 안정시키는 효과 또는 생리적 안정성에 1/f fluctuation의 ${\alpha}$기울기가 관계가 있는 것으로 보고되었다. 본 연구에서는 1/f fluctuation 수준을 총 3가지 나누어 제작한 사운드를 독립변수로 사용하였다. 독립변수는 감정노동 종사자에게 제시하여 그에 따른 심장반응을 측정하였다. 종속변수는 네 가지로 BPM(Beat Per Minute), VLF(Very Low Frequency), SDNN(Standard Deviation of NN intervals), 그리고 HF(High Frequency) 파워(Power)값을 확인하였다. 분석결과 기울기가 3인 1/fluctuation 사운드는 각성효과를 보였다. 기울기 1, 2인 사운드는 이완효과가 있는 것을 통계적으로 검증하였다. 이러한 1/f fluctuation 사운드의 특성을 활용해 감정 노동자들의 스트레스를 완화시키기 위한 서비스에 응용될 수 있을 것으로 사료된다.

• 대한통합의학회지
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• 제6권3호
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• pp.11-16
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• 2018

Purpose: Stress tends to cause sympathetic hyperactivity and increase blood cortisol levels. The vagus nerve is a parasympathetic nerve that is involved in relaxing the body. The purpose of this study was to investigate the effects of electrical stimulation of the vagus nerve on stress hormone (cortisol) levels and heart rate variability (HRV) in humans. Methods: A total of 10 healthy subjects participated in the pilot experiment. All subjects underwent electrical vagus nerve stimulation for 20 minutes in the cymba conchae of the left ear. An electro cardiogram meter was used to measure HRV. Blood samples were collected and analyzed for cortisol levels. The standard deviation of all normal N-N intervals (SDNN), root mean square of successive differences (RMSSD), low frequency, high frequency, and cortisol levels were compared in pre and post mean values after the intervention. Data were analyzed using the Wilcoxon's signed-rank test. Results: Coritsol levels were observed to decrease after vagus nerve electrical stimulation. The mean SDNN and RMSSD values were increased after the intervention, but not significantly. Conclusion: Vagus nerve electrical stimulation has been shown to increase the ability of the parasympathetic nerve to adapt to upward regulation and stress. Vagus nerve electrical stimulation could thus be an effective treatment for modern social psychological stress control.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.605-608
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• 2011

In this study, OSA (the obstructive sleep apnea) periods were detected in patients with OSA during sleep because of the treatment was different according to the frequency and symptoms of obstructive sleep apnea. ANS (autonomic nervous activity) was changed by obstructive sleep apnea periods so we intended to detect the periods to care the obstructive sleep apnea patients. RR intervals, SDNN (standard deviation of normal to normal) and RMSSD (root mean square standard deviation) were calculated in time domain analysis and LF (low frequency), HF (high frequency), NHF (normalized high frequency), NLF (normalized low frequency) were calculated in frequency domain analysis of HRV (heart rate variability) with obstructive sleep apnea patients. In this paper, SDNN (standard deviation of normal to normal) of time domain analysis were decreased in the obstructive sleep apnea periods. And NLF and LF/HF ratio were increased and NHF (normalized high frequency) was decreased in the frequency domain analysis. The parameters can be used to treat obstructive sleep apnea patients by detecting the obstructive sleep apnea periods such as CPAP (continuous positive airway pressure).

• 전기학회논문지
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• 제58권5호
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• pp.1050-1056
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• 2009

Heart Rate Variability(HRV) is a parameter that represents monitoring variability of time intervals between R-peak in electrocardiography. HRV serves to various applications, such as indices of autonomic functions, prediction of cardiac sudden death, assessment of stress and emotional, etc. However, as measuring R-peak in ECG needs at least 3-electrodes, and it is inconvenient for end users. In this paper, we suggested the modified laplacian electrodes for measuring HRV at one-point, which are producted by MEMS fabrication and have the two circular electrodes on the pad. For optimal position and direction, we performed an experiment that compared with pearson correlation coefficient and the amplitude of signals, between standard lead II and proposed electrodes. We analyzed the HRV parameters, such as standard deviation of the NN interval(SDNN), high frequency(HF), low frequency(LF), LF/HF ratio. The result showed that the average correlation coefficient and amplitude are 0.967 and 0.685 mVpp at the position 2. The coeffiecient correlation between the standard HRV and proposed electrode-HRV is 0.999

• The Korean Journal of Physiology and Pharmacology
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• 제4권3호
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• pp.253-261
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• 2000

Head-out water immersion induces marked increase in the cardiac stroke volume. The present study was undertaken to characterize the stroke volume change by analyzing the aortic blood flow and left ventricular systolic time intervals. Ten men rested on a siting position in the air and in the water at $34.5^{circ}C$ for 30 min each. Their stroke volume, heart rate, ventricular systolic time intervals, and aortic blood flow indices were assessed by impedance cardiography. During immersion, the stroke volume increased 56%, with a slight (4%) decrease in heart rate, thus cardiac output increased ${\sim}50%.$ The slight increase in R-R interval was due to an equivalent increase in the systolic and diastolic time intervals. The ventricular ejection time was 20% increased, and this was mainly due to a decrease in pre-ejection period (28%). The mean arterial pressure increased 5 mmHg, indicating that the cardiac afterload was slightly elevated by immersion. The left ventricular end-diastolic volume index increased 24%, indicating that the cardiac preload was markedly elevated during immersion. The mean velocity and the indices of peak velocity and peak acceleration of aortic blood flow were all increased by ${\sim}30%,$ indicating that the left ventricular contractile force was enhanced by immersion. These results suggest that the increase in stroke volume during immersion is characterized by an increase in ventricular ejection time and aortic blood flow velocity, which may be primarily attributed to the increased cardiac preload and the muscle length-dependent increase in myocardial contractile force.

• Journal of Acupuncture Research
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• 제22권6호
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• pp.51-60
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• 2005

Objectives : This study was designed to evaluate the effect of inbalance of autonomic nerve system on peripheral facial palsy patients in comparison of Heart Rate Variability results of healthy control group with that of peripheral facial palsy group. Methods : The peripheral facial palsy patiens who visited the Dongguk university Bundang oriental medicine hospital from April to June in 2005 were tested Heart Rate Variability items which are Mean Heart Rate(MHRT), Standard Deviation of all the Normal RR intervals (SDNN), Root Mean Square of Successive Differences Between The Normal Heart Beats(RMSSD), Total Power(TP), Low Frequency, High Frequency, ratio between the Low Frequency and High Frequency power(LF/HF ratio). The Heart Rate Variability test results of peripheral facial palsy group were compared with the HRV test results of healthy control group who didn't have nervous disease, musculoskeletal disease, heart problem and pain for the past 6 months. Results : 1. MHRT was not significantly different between peripheral facial palsy group and healthy control group(P=0.18). 2. SDNN was not significantly different between peripheral facial palsy group and healthy control group(P=0.41). 3. RMSSD was not significantly different between peripheral facial palsy group and healthy control group(P=0.93). 4. TP was not significantly different between peripheral facial palsy group and healthy control group(P=094). 5. LF and HF were not significantly different between peripheral facial palsy group and healthy control group((P=0.34, 0.30). 6. LF/HF ratio was significantly different between peripheral facial palsy group and healthy control group(P=0.04). Conclusion : LF/HF ratio is generally used as autonomic nerve system evaluation and there was significantly statistical difference between peripheral facial palsy group and healthy control group.