• Sleep Medicine and Psychophysiology
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• v.24 no.1
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• pp.32-37
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• 2017

Objectives: A supine sleep position increases sleep apneas compared to non-supine positions in obstructive sleep apnea syndrome (OSAS). However, supine position time (SPT) is not highly associated with apnea-hypopnea index (AHI) in OSAS. We evaluated the correlation among sleep-related variables and SPT in OSAS. Methods: A total of 365 men with OSAS were enrolled in this study. We analyzed how SPT was correlated with demographic data, sleep structure-related variables, OSAS-related variables and heart rate variability (HRV). Multiple linear regression analysis was conducted to investigate the factors that affected SPT. Results: SPT had the most significant correlation with total sleep time (TST ; r = 0.443, p < 0.001), followed by sleep efficiency (SE ; r = 0.300, p < 0.001). Snoring time (r = 0.238, p < 0.001), time at < 90% SpO2 (r = 0.188, p < 0.001), apnea-hypopnea index (AHI ; r = 0.180, p = 0.001) and oxygen desaturation index (ODI ; r = 0.149, p = 0.004) were significantly correlated with SPT. Multiple regression analysis revealed that TST (t = 7.781, p < 0.001), snoring time (t = 3.794, p < 0.001), AHI (t = 3.768, p < 0.001) and NN50 count (t = 1.993, p = 0.047) were associated with SPT. Conclusion: SPT was more highly associated with sleep structure-related parameters than OSAS-related variables. SPT was correlated with TST, SE, AHI, snoring time and NN50 count. This suggests that SPT is likely to be determined by sleep structure, HRV and the severity of OSAS.

• Journal of Pharmacopuncture
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• v.12 no.3
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• pp.31-40
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• 2009

Objective : This study was to investigate the effects of distilled Cervi Pantotrichum Cornu Pharmacopuncture and Zizyphi Spinosi Semen Pharmacopuncture on autonomic nervous system with Heart Rate Variability(HRV). Purpose of the trial was to observe what influence distilled Cervi Pantotrichum Cornu Pharmacopuncture and Zizyphi Spinosi Semen Pharmacopuncture have on the autonomic nervous system. Methods : 60 healthy male volunteers were divided into three groups which consist of two experimental groups such as Cervi Pantotrichum Cornu Pharmacopuncture and Zizyphi Spinosi Semen Pharmacopuncture, and a control group. Study design was a randomized, placebo-controlled, double-blind clinical trial. 20 subjects in experimental group were injected distilled Cervi Pantotrichum Cornu Pharmacopuncture at $GB_{21}$(Kyonjong), 20 subjects in other experimental group were injected distilled Zizyphi Spinosi Semen Pharmacopuncture and 20 subjects in control group were injected Normal Saline at $GB_{21}$(Kyonjong). One volunteer of each groups were excluded from analysis because of error during measuring HRV. At the end of the study 57 volunteers completed HRV analysis. HRV was measured by QECG-3:LXC3203(LAXTHA Inc. Korea) at P0, P1, P2, P3, P4, P5 and P6 and its time-course dependent change in each group was analyzed using paired t-test, and the difference of HRV fluctuation among two experimental group and a control was evaluated by one way ANOVA(p<0.05). Results : A. Time Domain Analysis 1. Analysis of Mean HRV, SDNN and Complexity After injection of distilled Cervi Pantotrichum Cornu Pharmacopuncture, Mean HRV was significantly decreased only at 20 minutes after injection. SDNN was significantly increased from 15 minute after injection. Complexity was significantly decreased only at 15 minute after injection. After injection of distilled Zizyphi Spinosi Semen Pharmacopuncture, Complexity was significantly decreased at 10, 15 and 30 minutes after injection. 2. Analysis of HRV index, pNN50 After injection of distilled Cervi Pantotrichum Cornu Pharmacopuncture, pNN50 was significantly decreased at 15, 20 and 25 minutes after injection. Compared with Normal Saline injection, distilled Cervi Pantotrichum Cornu Pharmacopuncture and Zizyphi Spinosi Semen Pharmacopuncture showed significant difference on HRV index and pNN50 at 5 minutes after injection. B. Frequency Domain Analysis 1. Analysis of Ln(TP), Ln(VLF) After injection of distilled Cervi Pantotrichum Cornu Pharmacopuncture, Ln(TP) was significantly increased at 15 and 30 minutes after injection. Ln(VLF) was significantly increased at 10, 15 and 30 minutes after injection. After injection of distilled Zizyphi Spinosi Semen Pharmacopuncture, Ln(VLF) was significantly increased only at 30 minutes after injection. Compared with Normal Saline injection, distilled Cervi Pantotrichum Cornu Pharmacopuncture showed significant difference on Ln(TP) after 5 minutes of injection. Conclusions : Our results suggest that Cervi Pantotrichum Cornu Pharmacopuncture and Zizyphi Spinosi Semen Pharmacopuncture in healthy adult man tend to activate the autonomic nervous system and sympathetic nervous system compared to Normal Saline within normal range.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.142-152
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• 2019

This study aimed to explore the association between obesity index and heart rate variability (HRV) in college-aged male smokers. A total of 85 male college students (> 10 cigarettes per day for at least 3 years) were participated in this study. According to a standardized protocol, body mass index (BMI), percent body fat (%BF), waist circumference (WC), and waist-to-hip ratio (WHR) were taken as obesity indices. Resting r-r interval was monitored for HRV analysis as an indicator of cardiac autonomic regulation. Compared with low WHR subjects, high WHR subjects had significantly lower values of rMSSD, pNN50, HF, and SD1, suggesting decreased parasympathetic activity. No such differences in LF/HF ratio were found between the WHR-based subgroups. Bivariate correlation analysis showed that obesity indices of WC, WHR, and %BF were significantly associated with rMSSD, pNN50, HF, and SD1, with a tendency for correlation coefficient to be higher with WHR than with WC or %BF. No significant association was found between BMI and HRV parameters indicative of parasympathetic activity. This study suggest that central obesity is significantly associated with decrease in parasympathetic activation, independent of BMI as an indicator of obesity, in male college smokers.

• Korean Journal of Psychosomatic Medicine
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• v.28 no.1
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• pp.89-97
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• 2020

Objectives : We investigated heart rate variability (HRV) patterns in patients with somatic symptom disorder (SSD) and the relationships of these patterns with alexithymia. Methods : In total, 42 patients with SSD and 33 healthy controls were enrolled in this study. Demographic, psychological, and HRV data were assessed at baseline, and 24 patients with SSD were reassessed after 6 months of treatment. The psychological data included somatic symptoms and levels of depression, anxiety, and alexithymia as indicated by the somatic symptom subscale of the Symptom Checklist 90-Revision (SCL-12), Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory (BAI), and the Toronto Alexithymia Scale 20 (TAS-20), respectively. Results : Patients with SSD had a lower standard deviation of normal-to-normal R-R intervals (SDNN) and lower proportions of adjacent R-R intervals greater than 50 milliseconds (pNN50) compared with controls. These HRV parameters were negatively correlated with alexithymia severity. After treatment, patients exhibited significantly decreased levels of somatic symptoms and reduced anxiety and depression, but there were no significant differences in the HRV parameters. In patients with alexithymia, a high baseline SDNN and pNN50 were associated with a decrease in somatic symptoms. Conclusions : Patients with SSD have different HRV patterns, and several HRV parameters are associated with alexithymia severity. These findings suggest that ANS regulation is involved in the pathophysiology of SSD, mediated by alexithymia. Furthermore, these results suggest that certain HRV parameters may be associated with clinical outcomes of SSD.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.224-230
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• 2011

In order to develop silk peptide (SP) preparations possessing cognition-enhancing effect, several candidates were screened through in vitro assays, and their effectiveness was investigated in facilitated brain aging model rats. Incubation of brain acetyl-cholinesterase with SP-PN (1-1,000 ${\mu}g/ml$) led to inhibition of the enzyme activity up to 35%, in contrast to a negligible effect of SP-NN. The expression of choline acetyltransferase (ChAT) mRNA of neural stem cells expressing ChAT gene (F3.ChAT) was increased by 24-hour treatment with 10 and 100 ${\mu}g/ml$ SP-NN (1.35 and 2.20 folds) and SP-PN (2.40 and 1.34 folds). Four-week subcutaneous injections with D-galactose (150 mg/kg) increased activated hippocampal astrocytes to 1.7 folds (a marker of brain injury and aging), decreased acetylcholine concentration in cerebrospinal fluid by 45-50%, and thereby impaired learning and memory function in passive avoidance and water-maze performances. Oral treatment with SP preparations (50 or 300 mg/kg) for 5 weeks from 1 week prior to D-galactose injection exerted recovering activities on acetylcholine depletion and brain injury/aging as well as cognitive deficit induced by D-galactose. The results indicate that SP preparations restore cognitive functions of facilitated brain aging model rats by increasing the release of acetylcholine, in addition to neuroprotective activity.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.370-377
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• 2018

Focus level has been important mental state in user study. Cardiac response has been related to focus and less clarified. The study was to determine cardiac parameters for recognizing focus level. The sixty participants were asked to play shooting game designed to control two focus levels. Electrocardiogram was measured during task. The parameters of time domain and frequency domain were determined from ECG. As a result of independent t-test, RRI, SDNN, rMSSD and pNN50 of time domain indicator were statistically significant in recognizing focus level. LF, HF, lnLF and lnHF of frequency domain were observed to be significant indicator. The rule base for recognition has been developed by the combination of RRI, rMSSD and lnHF. The rule base has been verified from another sixty data samples. The recognition accuracy were 95%. This study proposed significant cardiac indicators for recognizing focus level. The results provides objective measurement of focus in user interaction design in the fields of contents industry and service design.

• Science of Emotion and Sensibility
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• v.21 no.3
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• pp.73-82
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• 2018

Attempts have been made to recognize social emotion, including competition-cooperation, while designing interaction in work places. This study aimed to determine the cardiac response associated with classifying competition-cooperation of social emotion. Sixty students from Sangmyung University participated in the study and were asked to play a pattern game to experience the social emotion associated with competition and cooperation. Electrocardiograms were measured during the task and were analyzed to obtain time domain indicators, such as RRI, SDNN, and pNN50, and frequency domain indicators, such as VLF, LF, HF, VLF/HF, LF/HF, lnVLF, lnLF, lnHF, and lnVLF/lnHF. The significance of classifying social emotions was assessed using an independent t-test. The rule-base for the classification was determined using significant parameters of 30 participants and verified from data obtained from another 30 participants. As a result, 91.67% participants were correctly classified. This study proposes a new method of classifying social emotions of competition and cooperation and provides objective data for designing social interaction.

• Journal of Acupuncture Research
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• v.25 no.1
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• pp.15-23
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• 2008

Objectives : The aim of our study was to demonstrate the clinical application of a diagnosis relating the 7-zone-diagnostic system and heart rate variability. Materials and Methods : Subjects were divided into two groups according to the factor AA form of the 7-zone-diagnostic system(VEGA-DFM722, VEGA, Germany). Subjects in group A showed a factor-AA red bar graph in which zone 2 was higher than the normal range, and zone 6 was lower than the normal range. Subjects in group B showed a factor-AA red bar graph in which zone 2 was lower than the normal range, and zone 6 was higher than the normal range. We investigated how to differentiate the index of heart-rate variability(HRV, LX-3202, LAXTHA, Korea) for each group. We did independent sample t-tests and evaluated the results of the HRV at the 5% significance level using SPSS 10.0 for Windows. Results : The differences of the MeanRR, MeanHRV, SDNN, complexity, HRV-index, RMSSD, SDSD, and pNN50 values between the groups was not significant. The differences of the Ln(TP), Ln(VLF), Ln(HF), LF/(LF+HF), LF/HF, norm LF, and norm HF values between the groups was also not significant. The differences were not significant, but generally the values of SDNN, complexity, RMSSD, SDSD, Ln(VLF), Ln(HF) and norm LF for group B were higher than those for group A, and the values of pNN50 and norm HF for group B were lower than those for group A. Conclusions : This study suggests that differences in the HRV values between the groups was not significant, but group B has a tendency to be healthier than group A because of stress. Accordingly, further study will be required.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.1
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• pp.199-213
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• 2007

Purpose : This research was designed to determine whether HRV can be used as an assessment index in weakly postpartum women. Methods : The subjects were 232 women who admitted for postpartum care in Oriental Hospital of Woosuk University from 19, December 2005 to 21, July 2006. They took the test of CBC and HRV. And then we selected 200 cases of postpartum women. The SPSS 10.0 for windows was used to analyse the data and the simple correlation coefficient and the independent samples t-test were used to verify the results. Results : The following results were obtained : 1. There were positive correlations between items of CBC(RBC, Hb, Hct) and SDSD, RMSSD, SDNN, and also between items of CBC and log-transformed index of spectral analysis. There were negative correlations between items of CBC and Mean-HRV, pNN50. 2. SDNN of anemic postpartum women group significantly decreased compared with that of normal postpartum women group. HRV-Index, RMSSD and SDSD of anemic postpartum women group significantly decreased compared with that of normal postpartum women group. pNN50 of anemic postpartum women group significantly increased compared with that of normal postpartum women group. 3. Ln(TP), Ln(VLF), Ln(LF) and Ln(HF) of anemic postpartum women group significantly decreased compared with that of normal postpartum women group. Conclusion : The results suggest that the function of heart of anemic postpartum women group significantly decreased compared with that of normal postpartum women group.

• Journal of IKEEE
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• v.17 no.1
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• pp.22-28
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• 2013

According to a survey, more than 50% of the elders fall which is the most frequent daily safety accident of the elders takes place at home. Furthermore, the elders fall is anticipated to increase as more elderly people are expected to live alone since, 67.1% of the elders of 65 or more do not hope to live with their children. This research aims to verify the fall by measuring and analyzing the floor vibration, and the hardware system was also designed was Piezo Film Sensor, Op-Amp, and DAQ. The system is consists of signal processing part for measuring floor vibration and alarm part for identifying the consciousness of the user when the fall occurs. The fall detection by vibration signals verified by k-Nearest Neighbor verification, and the results showed the error rate of 3.8%.