• Journal of the Institute of Convergence Signal Processing
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• v.16 no.2
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• pp.50-55
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• 2015

The noise of MRI shooting is 100dB loud and has an intensive psychological and physiological influences on the human body. ECG signals were measured by experimental methods, while wearing earplugs for 15 minutes in the stable state. Then the ECG signals were measured for 30 minutes while listening to about 100dB of sound in a MRI equipment. In this study, the heart rate variability of men and women was analyzed according to the MRI noise stress level through the frequency analysis. As the MRI noise level is about 100dB, HRV analysis resulted in an imbalance between the sympathetic and parasympathetic. During the period from the resting state up to 10 minutes, the maximum stress state was shown. This study will encourage MRI workers to take interests in hearing protection for the patient and to make objective indicators about MRI noises.

• Journal of Acupuncture Research
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• v.26 no.5
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• pp.49-56
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• 2009

Objectives : The purpose of this study was to assess the effect of Hwangryunhaedok-tang pharmacopuncture at $CV_{17}$ for reducing mental stress using power spectrum analysis of the heart rate variability(HRV). Methods : 30 healthy volunteers(control group: 15, experimental group: 15) participated in this study. After instrumentation and 5-minutes rest period, mental stress by operation was provided for 5-minutes. HRV was recorded before and after the mental stress. And then the control group rested for 15-minutes. The experimental group was injected Hwangryunhaedok-tang pharmacopuncture at $CV_{17}$ and rested for 15-minutes. And then HRV was recorded. Results : In simple rest group, LF norm and HF norm showed a significant change after mental stress. In pharmacopuncture group, LF norm, HF norm and LF/HF showed a significant change after mental stress. But there were no significant difference between two groups(p>0.05). In pharmacopuncture group, LF norm, HF norm and LF/HF showed a significant change after pharmacopuncture injection. There were significant difference between two groups(p<0.01). Conclusions : The result suggests that Hwangryunhaedok-tang pharmacopuncture at $CV_{17}$(Jeonjung) can regulate and prevent the alteration of autonomic nerve system due to mental stress.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.1
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• pp.30-36
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• 2020

This study aimed to investigate heart rate variability (HRV) characteristics of cold pattern with repeated measurement data. Participants were taken from a Daejeon University cohort study from 2015 to 2018. Forty-seven of the participants studied displayed cold pattern while 23 showed signs of non-cold pattern. HRV was measured in supine position for 5 minutes at each year, and an 8-item cold pattern questionnaire was used for the diagnosis of cold pattern. SDNN (standard deviation of the NN intervals) and RMSSD (the square root of the mean squared differences of successive NN intervals) were used as time domain analysis, and TP (total power), VLF (power in very low frequency range), LF (power in low frequency range), HF (power in high frequency range), LF norm (LF power in normalized units), HF norm (HF power in normalized units) and LF/HF were used as frequency domain analysis. In the Mann-Whitney U test, LF norm, HF norm, and LF/HF showed differences between the cold pattern group and non-cold pattern group at every measurement, and in the independent t-test, the differences were also observed at three points except for the baseline (2015). In the repeated measures ANOVA, the interaction effects were not observed in all HRV parameters, but the time period effects were observed in SDNN, RMSSD, TP, VLF, LF and HF. There were significant differences between those two groups in LF norm, HF norm and LF/HF. This study suggests that LF norm, HF norm and LF/HF might be a useful indicator of cold pattern properties.

• Atmosphere
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• v.22 no.1
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• pp.1-12
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• 2012

The Atmospheric motion vectors (AMVs) derived using infrared (IR) channel imagery of geostationary satellites have been utilized widely for real-time weather analysis and data assimilation into global numerical prediction model. As the horizontal resolution of sensors on-board satellites gets higher, it becomes possible to identify atmospheric motions induced by convective clouds ($meso-{\beta}$ and $meso-{\gamma}$ scales). The National Institute of Meteorological Research (NIMR) developed the high resolution visible (HRV) AMV algorithm to detect mesoscale atmospheric motions including ageostrophic flows. To retrieve atmospheric motions smaller than $meso-{\beta}$ scale effectively, the target size is reduced and the visible channel imagery of geostationary satellite with 1 km resolution is used. For the accurate AMVs, optimal conditions are decided by investigating sensitivity of algorithm to target selection and correction method of height assignment. The results show that the optimal conditions are target size of 32 km ${\times}$ 32 km, the grid interval as same as target size, and the optimal target selection method. The HRV AMVs derived with these conditions depict more effectively tropical cyclone OMAIS than IR AMVs and the mean speed of HRV AMVs in OMAIS is slightly faster than that of IR AMVs. Optimized mesoscale AMVs are derived for 6 months (Feb. 2010-Jun. 2010) and validated with radiosonde observations, which indicates NIMR's HRV AMV algorithm can retrieve successfully mesoscale atmospheric motions.

• Journal of Korean Medicine for Obesity Research
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• v.8 no.1
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• pp.63-70
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• 2008

Objectives Obesity is the major risk factor of the heart disease and the metabolic disease. The autonomic nervous system is a key contributor in the regulation of energy balance, so the blunted activity may contribute to the maintenance of the obese state. So we evaluated the function of the autonomic nervous system in young overweight and obese women with heart rate variability. Methods The subjects were 26 overweight and obese young women(BMI〉$23kg/m^2$) and 25 lean women who visited Kangnam Kyunghee hospital for obesity management from March 2006 to April 2008. Bioimpedance Analysis (BIA), short-term spectral analysis of heart rate variability (HRV) were performed. Results HRV of obese young group was lower than the lean young group, but there is no statistical significance. BMI had significantly a negative correlation with Low Frequency(LF) of HRV. LF power is mediated by sympathetic nervous system activity. These results indicate a decrease of sympathetic modulation in overweight and obese young women. Conclusions Overweight and obese young women have decreased sympathetic nervous system activity. In clinical practice, an assessement of HRV would be noninvasive and sensitive methods for sympathetic nervous system of young overweight and obese women.

• Journal of Acupuncture Research
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• v.27 no.2
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• pp.51-58
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• 2010

Objectives : The purpose of this study was to assess the effect of $PC_6$ moxibustion treatment for reducing mental stress using power spectrum analysis of the heart rate variability(HRV). Methods : 20 healthy volunteers(simple rest group : 10, moxibustion treatment group : 10) participated in this study. After instrumentation and 5-minutes rest period, mental stress by operation was provided for 5-minutes. HRV was recorded before and after the mental stress. And then the simple rest group rested for 15-minutes. The moxibustion treatment group was treated by $PC_6$ moxibustion and rested for 15-minutes. And then HRV was recorded. Results : In simple rest group, LF norm and HF norm showed a significant change after mental stress. In moxibustion treatment group, LF, HF, LF norm, HF norm and LF/HF showed a significant change after mental stress. But there were no significant difference between two groups(p>0.05) except HF. In moxibustion treatment group, LF, LF norm, HF norm and LF/HF showed a significant change after moxibustion treatment. There were significant differences between two groups(p<0.05). Conclusions : The result suggests that $PC_6$ moxibustion treatment can regulate and prevent the alteration of autonomic nerve system by mental stress.

• Journal of Oriental Neuropsychiatry
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• v.14 no.2
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• pp.135-143
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• 2003

Objectives : The purpose of this study is to analyze and compare heart rate variability(HRV) of patient of twenties and thirties diagnosed as Kiwooljeung with healthy controls'. Methods : We measured HRV of 35 patient(20 to 39 years old, male 14, female 11) diagnosed as Kiwooljeung and 40 healthy controls(male 24, female 16). HRV was measured by SA-3000P(Medicore, Korea) for 5 minutes after 5 minutes resting. Results : 1. In time domain analysis, Mean pulse rate(PRT) in Kiwooljeung group was higher than healthy controls. Standard deviation of all normal N-N intervals (SDNN) in Kiwooljeung group was lower and the results of twenties and thirties were same. 2. In frequency domain analysis, total power(TP), very low frequency(VLF), low frequency(LF), high frequency(HF), Ln TP, Ln VLF, Ln LF, Ln HF in Kiwooljeung group were lower than healthy controls but LF/HF ratio was higher than healthy controls. 3. Comparing gender in Kiwooljeung group, LF/HF ratio in male was higher than female. Conclusions : This study suggests lower activity and imbalance of cardiac autonomous nervous system in Kiwooljeung with the age group between twenties and thirties.

• Journal of Digital Contents Society
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• v.8 no.3
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• pp.355-363
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• 2007

One of major factors for learning achievement is the student's learning preference according to his character type. In course of learning, if a student studies e-learning contents opposed to his preference, then he would be under stress and his blood pressure and heart beat be changed. For measuring unwillingness, we used spectral components in frequency domain known as stress measure. For 13 children attending kindergarten we examined S(sensing)/ N(intuition) of MBTI and presented same learning contents during 10 minutes. During learning we gathered ECG signals, changed into HRV(heart rate variability), transformed time-varying HRV signal into spectral density in frequency domain. And then, we divided it into three areas of low(LF), middle(MF), and high-frequency(HF) and calculated stress measures by rates of those frequency area. We compared estimated stress measures of S group with them of N group whether students in different group preferred different contents or not. Experimental shows that students according to MBTI type prefer different contents.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.2
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• pp.101-111
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• 2010

Objectives : The purpose of this study was to investigate differences between traffic accident and non-traffic accident patients in the early stage, by analysis of the heart rate variability(HRV) and visual analogue scale(VAS). Methods : This study carried out on 38 patients who complained of nuchal or lower back pain. They have received hospital treatment in Dae-Jeon Univ. Cheonan Oriental Hospital. In the TA(Traffic accident) group, the pain caused by TA and in non-TA group, the pain caused by other reasons. We measured HRV and VAS twice(pre-treatment(Tx.) and post-Tx.). Then we analyzed the data. Results : As time goes by, patients who complained of pain showed the inclination to improve ability to balance autonomic nerve system. And fatigue and pain were improved. But they showed the inclination to increase stress index. At pre-Tx., TA group had more stress and worse ability to balance autonomic nerve system, but showed lower fatigue index than non-TA group. But, as time goes by, in TA group the fatigue and autonomic balance got worse. At pre-Tx., non-TA group complained of more severe pain than TA group, but at post-Tx., TA group complained of more severe pain than non-TA group. In other words, in TA group, the decreasing rate of pain was lower than non-TA group. Conclusions : Results from this investigation showed that TA have a negative effect on stress index, ability to balance autonomic nerve system, fatigue index and decreasing rate of pain. These results are expected to consider characteristics of patients who complained of pain caused by TA.

• The Journal of Korean Obstetrics and Gynecology
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• v.32 no.4
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• pp.25-38
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• 2019

Objectives: The purpose of this study is to analysis differences of heart rate variability (HRV), body composition, digital infrared thermal imaging (DITI), and electro pulse graph by whether there are some causes of dysmenorrhea or not. Methods: We studied 89 patients who took at least one test among HRV, Body composition, DITI, and electro pulse graph visiting Kyung Hee University Hospital at Gangdong from March 1, 2014 to May 7, 2019. Results: There were statistically significant differences in Low frequency (LF), LF norm and High frequency norm (HF norm) of HRV between primary dysmenorrhea patients and secondary dysmenorrhea patients. There were statistically significant differences in Body Mass Index (BMI) and body fat percentage of Body composition between two groups. But both BMI were included in normal range. There were no statistically significant difference in DITI results. And there was significant difference of Estimated circulation resistance (ECR) between two groups. Conclusions: The results suggest that hormone imbalance of secondary dysmenorrhea patients can affect HRV results. And because of high ECR, phlegm pathology can be more considered in secondary dysmenorrhea patients. Further study should be conducted to confirm the results of body composition and DITI differences.