• Korean Journal of Psychosomatic Medicine
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• v.12 no.1
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• pp.3-14
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• 2004

In this article, the effects of stress on central nerve system and heart function and the concept of heart rate variability were reviewed. HRV(Heart Rate Variability), the periodical change of the heart rate, is indicated larger in the healthier because they respond flexibly to various sorts of facts influencing on HR. HRV analysis is largely composed of the time domain analysis and the frequency analysis. In the former the flexibility of heart function is analysed, while in the latter autonomic nerve function is examined, which is the degree of sympathetic and parasympathetic nerve activity and the state of balance. Furthermore, existence or nonexistence of disease and/or level of stress can be estimated by measuring the variability and normality of heart rate, and balance of autonomic nerve system, and through HRV biofeedback the symptoms of anxiety disorder or asthma can be reduced.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.271-280
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• 2011

Heart Rate Variability (HRV) analysis is a convenient tool to assess Myocardial Ischemia (MI). The analysis methods of HRV can be divided into time domain and frequency domain analysis. This paper uses wavelet transform as frequency domain analysis in contrast to time domain analysis in short term HRV analysis. ST-T and normal episodes are collected from the European ST-T database and the MIT-BIH Normal Sinus Rhythm database, respectively. An episode can be divided into several segments, each of which is formed by 32 successive RR intervals. Eighteen HRV features are extracted from each segment by the time and frequency domain analysis. To diagnose MI, the Neural Network with Weighted Fuzzy Membership functions (NEWFM) is used with the extracted 18 features. The results show that the average accuracy from time and frequency domain features is 75.29% and 80.93%, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.349-352
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• 2009

최근 유비쿼터스 헬스케어가 부각됨에 따라 심장의 활동상태를 보다 편리하게 측정하기 위하여 이동성 및 휴대성을 강조한 심전도 계측 시스템 및 스트레스 상태를 분석하기 위한 연구들이 수행되고 있다. 하지만 기존 심전도 계측은 전극의 부착 및 계측시스템과의 연결을 위한 리드선의 사용으로 인해 활동의 불편함을 유발한다. 본 연구에서는 기 연구 수행된 가정 또는 사무실에서 무구속적인(unconstrained) 방법으로 지속적인 심장의 활동상태의 모니터링이 가능한 무구속 의자형 심탄도 계측 시스템을 구현하였다. 무구속적인 방법으로 심탄도 신호를 계측하고 심탄도신호로부터 심박동변이율을 추출함으로써 일상생활 중 스트레스를 모니터링 하고자 하였다. 구현된 시스템을 통한 스트레스 모니터링의 가능성을 평가하기위하여 안정상태의 심박동변이율과 인위적인 신체적 스트레스인 Valsalva 조작를 유도한 후 심박동 변이율을 비교평가 하였다. 건강한 대학생 10명을 대상으로 비교분석을 수행한 결과 안정 상태와 육체적 스트레스 인가 후 심박동 변이율의 변화 양상을 관찰할 수 있었으며, 무구속적인 방법에 의해 스트레스의 모니터링이 가능함을 확인 할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1689-1692
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• 2013

NUI(Natural User Interface)는 사용자가 신체부위를 사용하여 인터페이스 할 수 있는 기술이다. 본 연구에서는 NUI 공간에서 체감형 게임을 시행하였다. 게임은 태권도게임으로 사용자와 컴퓨터간의 대련이며, 게임 시 사용자의 심전도 신호를 측정하였다. 사용자는 심전도데이터를 게임 시에 사용자 프로파일로 전송한다. 전송받은 심전도신호로 사용자의 심박변이도를 분류하여 분류기 실험을 시행하고 정확도를 측정하였다. 실험은 체감형 게임 시행 전과 시행 후의 상태로 나누어 실험하였으며, 분류기는 Decision Tree를 사용하였다. 실험결과 심박변이율은 게임 시행 후 정확도가 4.16% 높게 도출되었다.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.996-1002
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• 2003

Purpose : In Rett syndrome patients, the incidence of sudden death is greater than that of the general population, and cardiac electrical instability including fatal cardiac arrhythmia is a main suspected cause. In this study, we are going to find out the possible cause of the higher risk of sudden death in Rett patients by the evaluation of heart rate variability, a marker of cardiac autonomic activity and corrected QT intervals. Methods : Diagnosis of Rett syndrome was made by molecular genetic study of Rett syndrome (MECP2 gene) or clinical diagnostic criteria of Rett syndrome. Heart rate variability and corrected QT intervals were measured by 24 h-Holter study in 12 Rett patients, and in 30 age-matched healthy children with chief complaints of chest pain or suspected heart murmurs. The were compared with the normal age-matched control. Results : Patients with total Rett syndrome, classic Rett syndrome, and Rett variants had significantly lower heart rate variability(especially rMSSD)(P<0.05) and longer corrected QT intervals than age-matched healthy children(P<0.05). Sympathovagal balance expressed by the ratio of high to low frequency(LF/HF ratio) also showed statistically significant differences between the three groups considered(P<0.05). Conclusion : A significant reduction of heart rate variability, a marker of autonomic disarray, suggests a possible explanation of cardiac dysfunction in sudden death associated with Rett syndrome.

• Sleep Medicine and Psychophysiology
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• v.24 no.1
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• pp.46-54
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• 2017

Objectives: Domestic violence is related to many psychiatric diseases, such as depression, anxiety disorder, and PTSD. Heart rate variability (HRV) is an index of autonomic control of the heart and is related to cardiovascular and emotional disorders. Although there have been some studies on the effects of domestic violence on women's mental health, relatively little information is available on HRV in this population. The aim of this study is to investigate demographic data, psychological features, and HRV in female victims of domestic violence and difference between Korean and foreign female victims. Methods: A total of 210 female victims of domestic violence (166 Korean women and 44 foreign women) were recruited for this study. Psychological symptoms were measured using the Hamilton Rating Scale for Anxiety (HAM-A), Hamilton Rating Scale for Depression (HAM-D), and Impact of Event Scale-Revised (IES-R). HRV measures were assessed by time-domain and frequency-domain analyses. Results: The mean score of HAM-A was 13.81, that of HAM-D was 12.92, and that of IES-R was 33.61 ; there were no significant differences between Korean and foreign women in these measures. In HRV time domain analyses, approximate entropy (ApEn) was significantly increased in foreign women compared to the Korean women. The square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD) was significantly decreased in foreign women compared to Korean women. There were no significant differences in the other HRV variables between Korean and foreign women. Conclusion: Female victims of domestic violence in Korea are associated with depression, anxiety, and PTSD symptoms. The physiologic factors of a female victim's nationality could be related to higher ApEn and lower RMSSD in foreign female victims. These findings have important implications for future study to study the relationships among ethnic and environmental factors and HRV variables.

• Korean Journal of Acupuncture
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• v.27 no.4
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• pp.85-97
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• 2010

목적 : 이 연구는 서로 다른 두 경혈이 심박변이도에 미치는 영향을 비교하고, 자율신경계에 미치는 영향을 평가하기 위해 수행하였다. 재료 및 방법 : 13명의 지원자가 3개의 세션에 균등하게 무작위 배정되었다. 각 세션에서 지원자들은 신맥(BL62), 조해(KI6), 또는 비경혈에 각각 침처치를 받았다. 10분간 휴식을 한 후에 자침 전, 유침기간, 발침 후 기간에 5분 동안 심박변이도 측정을 하였다. 유침기간에는 2분 간격을 두고 2회 심박변이도를 측정하였다. 결과 : 신맥에 자침한 군에서는 자침후 기간에 total power(TP)와 standard deviation N-N interval(SDNN)이 유의하게 증가하였다. 유침기간 중 첫 5분 동안의 TP와 SDNN은 자침전 값과 유의한 차이가 없었으며 유침기간 중 마지막 5분 동안에는 다소 증가하는 경향은 있었지만 통계적인 유의성은 없었다. 반면에 조해와 비경혈에 자침한 군에서는 TP와 SDNN에 유의한 변화가 관찰되지 않았다. 발침 후에 신맥자침군에서는 조해와 비경혈 자극군과 비교해서 TP가 유의하게 변화하였다. 그러나 SDNN은 발침 후에 세 군 사이에 유의한 차이가 없었다. 결론 : 이 실험 결과는 조해와 비교했을 때 신맥에 자침한 경우 심장 기능 및 자율신경계와 관련이 있는 대체적인 활성이 증가한다는 것을 보여주었다. 이 결과는 신맥 자침이 자율신경계와 관계되어 있는 심장의 기능에 미치는 영향을 통해서 경혈의 특이성을 관찰할 수 있음을 의미한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5578-5584
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• 2014

In this study, 46 patients from a local hemodialysis center were enrolled to assess the effects of a self-motivated virtual reality (VR) exercise program on the heart rate variability and quality of life control in hemodialysis patients. The VR group (n = 23) completed a VR exercise program, where the subjects performed the exercise 40 min per session, 3 sessions per week, for 8weeks. After the exercise program, the heart rate variability and quality of life were measured. The VR group showed significant improvement in the heart rate variability and quality of life. The self-motivated VR exercise program provided both the role of supervisor as well as feedback, which is important for hemodialysis patients.Therefore, a self-motivated VR exercise program may be a useful tool for improving the psychosocial function in chronic disease patients undergoing hemodialysis.

• Korean Journal of Psychosomatic Medicine
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• v.14 no.1
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• pp.33-38
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• 2006

Biofeedback training to increase the amplitude of respiratory sinus arrhythmia(RSA) maximally increases the amplitude of heart rate variability(HRV) only in respiratory rate at approximately 0.1Hz. To perform this task, people slow their breathing to this rate to point where resonance occur between respiratory sinus arrhythmia(RSA) and oscillation that naturally occur at this rate, probably triggered in part by baroreflex activity. The biofeedback technique allows each individual to breathe at a rate that is specifically adapted to the rhythms of his or her own body. A manual is presented for carrying out this method.

• Korean Journal of Biological Psychiatry
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• v.15 no.1
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• pp.35-45
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• 2008

Objectives : There has been a continued debate regarding the role of eye movements in Eye Movement Desensitization and Reprocessing(EMDR). This study examined the possible autonomic effect of horizontal eye movements after being exposed to fearful stimuli. Methods : Fifty two healthy adult women were randomly allocated to eye movement or eye fixed groups after watching a five minute fear-inducing film clip. ECG was recorded during the resting state, after watching the clip, and the treatment. A spectral power analysis of the heart rate variability was performed. As the variables violated the rule of normal distribution and the number in each group is small the non-parametric test was used. Results : Overall, we did not find the differences between the groups in both time and frequency domains. Some minor differences found were not consistent with results from previous studies. Conclusions : Effect of eye movement on autonomic nervous system during fear desensitization was not supported in this experiment. Further study with other psychophysiological measures is needed to understand the role of eye movements in treatment of traumatic memory.