• Title/Summary/Keyword: LF/HF ratio

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Clinical Study for Characteristics of Heart Rate Variability in Stroke Patients (중풍 환자의 심박변이도 특성에 대한 임상적 연구)

  • Lee, ln-whan;Shin, Ae-sook;Kim, Na-hee;Kim, Hye-mi;Shim, So-ra;Kim, Min-kyung;Cho, Seung-yeon;Na, Byung-jo;Jung, Woo-sang;Moon, Sang-kwan;Park, Jung-mi;Ko, Chang-nam;Cho, Ki-ho;Kim, Young-suk;Bae, Hyung-sup;Park, Seong-uk
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.11 no.1
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    • pp.1-8
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    • 2010
  • Objectives : We designed this study to investigate difference of heart rate variability(HRV) according to sex, age, acute or chronic phase, category of stroke, national institute of health stroke scale(NIHSS), lesion of stroke. Methods : 64 subjects were recruited from the patients admitted to the department of oriental medicine at East-West Neo Medical Center, Kyung Hee University from 1 September 2009 to 31 August 2010. We compared heart rate(HR), standard deviation of all normal P-P intervals(SDNN), low frequency(LF), high frequency(HF), LF/HF ratio. Results and Conclusions : 1. LF/HF ratio is significantly different between over-70 and below-70 of age. 2. SDNN is significantly different between acute and chronic stroke patients. 3. In sex, category of stroke, national institute of health stroke scale(NIHSS), lesion of stroke, there are no significantly different among the any values of heart rate variability(HRV).

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An Analysis of Relationship between Self-Reported Anxiety, Depressiveness and Parametors of Heart rate variability based on Photoplethysmography (불안 및 우울에 대한 주관적 설문평가 지표와 맥파 신호 기반의 심박변이도 요소들 간의 상관관계 분석)

  • Lee, Chung-Ki;Yoo, Sun-Kook
    • Science of Emotion and Sensibility
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    • v.15 no.3
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    • pp.345-354
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    • 2012
  • The purpose of this study is finding alternative parameters of the HRV so as to minimize the subjective errors by STAI and BDI, could be have two types of significant correlation levels depending on normalized method. Particularly, the LF/HF presented as the quantitative physiological parameter that can reflect both state-anxiety and trait-anxiety.

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Multi-layer resist (MLR) structure with a very thin DLC layer

  • Kim, H.T.;Kwon, B.S.;Park, S.M.;Lee, N.E.;Cho, H.J.;Hong, B.Y.
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2007.04a
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    • pp.71-72
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    • 2007
  • In this study, we investigated the fabrication of MLR (multi-layer resist) with a very thin diamond-like carbon (DLC) layer. ArF PR/$SiO_2$/DLC MLR structure was investigated and etching characteristics of the DLC layer was patterned using $SiO_2$ hard-mask by varying the process parameters such as different high-frequency/low-frequency combination ($f_{LF}/f_{HF}$), HF/LF power ratio ($P_{HF}/P_{LF}$), $O_2$ flow and $N_2$ flow rate in $O_2/N_2$/Ar plasmas. The results indicated an increased etch rate of DLC for the higher $f_{LF}/f_{HF}$ combination and for the increased low-frequency power ($P_{LF}$). And the etch rate of DLC was decreased with increasing the $N_2$ flow rate in $O_2/N_2$/Ar plasmas. In order to confirm the application of DLC MLR for the etching process of silicon oxide, the stack of ArF PR/BARC/$SiO_2$/DLC/TEOS/Si was investigated.

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A Study on the Effects of Chinese Qigong and Kundalini Yoga Meditations on the Heart Rate Variability of Skilled Students (중국 기공 및 쿤달리니 요가 명상이 숙련자의 심박변이율(HRV) 변화에 미치는 영향에 관한 연구)

  • Jang, Dae-Geun;Jang, Jae-Keun;Park, Seung-Hun;Hahn, Minsoo
    • Journal of Biomedical Engineering Research
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    • v.33 no.3
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    • pp.141-147
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    • 2012
  • In this paper, we have investigated effects of two specific meditations (Chinese qigong meditation and Kundalini yoga meditation) on the heart rate variability (HRV), which is a well-known quantitative measure of autonomic balance, of skilled students. To analyze the effects, the MIT/BIH physionet database was utilized. The database includes RR intervals of eight skilled Chinese qigong meditators (5 women and 3 men; age range 26-35) and four skilled Kundalini yoga meditators (2 women and 2 men; age range 20-52). RR intervals of each subject were measured before and during the meditations. For HRV analysis, we have used typical four HRV parameters - the low frequency to high frequency power ratio (LF/HF ratio), SD2/SD1 ratio, sample entropy, and fractal dimension. The LF/HF ratio was calculated by the autoregressive spectrum and the SD2/SD1 ratio was derived from the Poincar$\grave{e}$ plot. The sample entropy was computed from the phase space plot and the fractal dimension was estimated by the Higuchi's algorithm. In the experiments, the Wilcoxon signed rank test was employed because we used small datasets and compared HRV parameters before and during the meditations. As a result, we have found increment of the LF/HF and SD2/SD1 ratios in both meditations; whereas the sample entropy is decreased during the meditations. In addition, the fractal dimension is increased during the Chinese qigong meditation; whereas it is decreased during the Kundalini yoga meditation. The results show that the sympathetic nervous system is generally more activated in skilled Chinese qigong and Kundalini yoga meditators, but the activation of the parasympathetic nervous tone is suppressed.

The Effects of LI4, TE3, TE5 and LI11 Moxibustion on Radial Artery Blood Flow and Heart Rate Variability in Stoke Patients with Hemiplegia (합곡.중저.외관.곡지 뜸치료가 뇌졸중 편마비 환자의 환측 요골동맥 혈류 및 심박변이도에 미치는 영향)

  • Yoon, Seung-Kyou;Kwon, Seung-Won;Seo, Yu-Ri;Park, Joon-Young;Im, Jin-Wook;Park, Joo-Young;Cho, Seung-Yeon;Jung, Hwan-Yong;Park, Sung-Wook;Jung, Woo-Sang;Moon, Sang-Kwan;Park, Jung-Mi;Ko, Chang-Nam;Cho, Ki-Ho;Kim, Young-Suk;Bae, Hyung-Sup;Lee, Sang-Hoon;Bae, Young-Min
    • The Journal of Korean Medicine
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    • v.32 no.5
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    • pp.50-65
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    • 2011
  • Objectives: Moxibustion has been used for various post-stroke symptoms and has also been known to have effect on peripheral blood flow. This study investigated the effect of moxibustion on radial artery blood flow by Doppler ultrasound and on heart rate variability in post-stroke hemiplegia patients. Methods: Moxibustion was applied on the points of LI4, TE3, TE5 and LI11 on the affected side, and blood flow of the radial artery was measured using the Minimax-Doppler-K device. Blood flow velocity and pulsation index were analyzed before, during, and after moxibustion. Simultaneously LF, HF, and LF/HF as variables for HRV were measured by FM-150. Results: The mean value of blood flow velocity in all patients (n=23) showed significant increase between before and after moxibustion, but there was no significant difference in pulsation index and LF, HF, LF/HF ratio between before and after moxibustion. In Yin (n=9) and Yang (n=14) groups, both showed significant increase of blood flow velocity between before and after moxibustion, but there was no significant difference in pulsation index and LF, HF, LF/HF ratio between before and after moxibustion. In Deficiency (n=14) and Fullness (n=9) groups, only the Deficiency group showed significant increase of blood flow velocity between before and after moxibustion, while the Fullness group showed no significant difference in blood flow velocity between before and after moxibustion, and also there was no significant difference in pulsation index and LF, HF, LF/HF ratio between before and after moxibustion. Conclusions: This study suggests that moxibustion on LI4, TE3, TE5 and LI11 on the affected side of stroke patients increase the peripheral blood flow in the affected arm, which was most remarkable in those with Yin and Deficiency pattern.

Autonomic Nervous Response of Female College Students with Type D Personality during an Acute Stress Task: Heart Rate Variability (Type D 성격 여대생의 급성 스트레스에 따른 자율신경계 반응 : 심박률 변동성을 중심으로)

  • Ko, Seon-Young;Kim, Myung-Sun
    • Korean Journal of Health Psychology
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    • v.14 no.2
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    • pp.277-292
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    • 2009
  • This study investigated the responses of the autonomic nervous system of individuals with Type D personality during an acute stressful situation. Twenty-three female students of Type D personality and 23 female students with non-Type D personality. Stroop Color-Word Task was used to induce a stressful situation, heart rate variability (HRV) was used to measure the responses of the autonomic nervous system during the baseline, acute stress, recovery periods. To analyze the data, the repeated measures analysis of variance was used to compare the autonomic nervous system of the Type D group to that of the non-Type D group. Regression analysis is used to determine if the Type D scale and stress vulnerability predicted the activities of the autonomic nervous system during the baseline period. The results of this study demonstrated that the Type D group's normalized low frequency (LF norm) and ratio of low frequency to high frequency (LF/HF ratio) were higher than those for the non-Type D group, while its normalized high frequency (HF norm) was lower than that for the non-Type D group in all three periods. There were no statistically significant differences among the three periods in terms of LF norm, HF norm, and LF/HF ratio in the Type D group. The study demonstrated that the total scores of the Type DS-14 and scores of social inhibition and negative affect were independent predictors of LF norm and HF norm during the baseline. The Type D group showed increased activation of the sympathetic nervous system and/or decreased activation of the parasympathetic nervous system. These results support the hypothesis that the Type D personality is vulnerable to the stress. Also, the highly activated sympathetic and/or lowly activated parasympathetic nervous systems, which were observed in the Type D group during the baseline, indicated that the Type D individual is susceptible to psychosomatic disorders.

Parasympathetic Modulation Plays a Key Role in Initiation of Paroxysmal Atrial Fibrillation

  • Lee, Won-Jae;Shin, Dong-Gu;Hong, Geu-Ru;Park, Jong-Sun;Kim, Young-Jo
    • Journal of Yeungnam Medical Science
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    • v.24 no.2
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    • pp.216-231
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    • 2007
  • Background : An acceleration or deceleration of the heart rate (HR), which reflects autonomic effects, is observed before the onset of paroxysmal atrial fibrillation (PAF). The purpose of this study was to assess the discrepancy in the autonomic interactions before the onset of PAF for different patterns of change in the HR. Materials and Methods : From 105 Holter tapes with the PAF recorded, 55 episodes (42 patients, 34 men, $58{\pm}12$ years) of PAF (>5 min), preceded by a sinus rhythm for more than 1 hour, were selected and submitted to time-domain and frequency-domain HR variability analyses. Fifty-five episodes were divided into 2 groups: group A PAF (n=30) with acceleration of the HR during the last 2 minutes before the PAF and group B (n=25) with deceleration of the HR. Results : A significant linear decrease in the mean R-R interval was observed in group A ($924{\pm}30$ to $835{\pm}28ms$, $P$=0.001) and an increase from $831{\pm}32$ to $866{\pm}31ms$ in group B PAF episodes ($P$=0.046). In the frequency-domain analyses, the LF/HF ratio exhibited a progressive linear increase before the PAF in group A ($P$=0.005). The HF normalized units (HFnu) and natural logarithm-transformed HF ($In$HF) values decreased from $30.8{\pm}4.0$ to $16.1{\pm}1.8$ ($P$=0.003) and $4.49{\pm}0.25$ to $4.07{\pm}0.22$ ($P$=0.001), respectively. Contrary to the results in group A, a significant increase in the HF components (HFnu and $In$HF) (from $22.6{\pm}3.2$ to $30.2{\pm}4.0$, $P$=0.005, and $4.27{\pm}0.27$ to 4.75 0.33, $P$=0.001, respectively) and a resultant decrease in the LF/HF ratio were observed in group B PAF episodes. No significant changes were observed in the LF components in either PAF group. Conclusion : Autonomic stimuli leading to an acceleration or deceleration of the HR before the onset of AF are due to parasympathetic modulation. Parasympathetic modulation plays a key role in the initiation of PAF.

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Evaluation of Horticultural Therapy on the Emotional Improvement of Depressed Patients by Using Heart Rate Variability (심박변이도를 이용한 우울증 환자의 정서개선에 미치는 원예치료 효과 분석)

  • Song, Mi-Jin;Kim, Mi-Young;Sim, Iee-Sung;Kim, Wan-Soon
    • Horticultural Science & Technology
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    • v.28 no.6
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    • pp.1066-1071
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    • 2010
  • To evaluate the effect of horticultural therapy (HT) on the emotional improvement of depressed patients, computer-based heart rate variability (HRV) was compared with self-report scale (SRS) known as existing subjective evaluation method. SRS included four test areas: mental stress scale (MSS), physical stress scale (PSS), Beck anxiety inventory (BAI), and Beck depression inventory (BDI). HRV was itemized into four parameters: standard deviation of the N-N intervals (SDNN), square root of mean squared difference of successive N-N intervals (RMSSD), total power (TP), and low-frequency/high-frequency ratio (LF/HF ratio). Thirty patients with depression at the same mental hospital participated in this study. 15 patients of the treatment group received HT once a week for three months, but the control group did not during the same period. As a result, the emotional improvement in treatment group was clearly identified through HRV as well as SRS. The significant difference was shown at three test areas (MSS, BAI, and BDI, $p$ < 0.001) in SRS and at one parameter (total power, $p$ < 0.05) in HRV. There was noticeable increase in SDNN, RMSSD, and LF/HF ratio in treatment group after HT activity, but no significant difference. Although all parameters of HRV did not show significance, the possibility of HRV as an objective evaluation method to HT was recognized in this study. These results also implied that HT was efficient in the mental and physical regeneration of the depressed patients in both subjective and objective evaluation methods.

Effects of Self-stretching and Joint Mobilization to Upper Thoracic Vertebrae in Craniovertebral Angle and Autonomic System Function in Chronic Cervical Pain (만성 목통증에 대한 자가신장과 위등뼈 관절가동술이 머리척추각 및 자율신경계 기능에 미치는 효과)

  • Nam, Ki-Won;Kim, Se-Hun;Seo, Dong-Yel
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.2
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    • pp.61-68
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    • 2018
  • PURPOSE: This study aimed to examine the effects of self-stretching (SS) and joint mobilization (JM) on pain, craniovertebral angle (CVA), autonomic system function in chronic cervical pain patient with forward head posture (FHP). METHODS: A total of 30 male college students were selected as study subjects, and were divided into Group I (general physical therapy; GPT, n=10), Group II (GPT+SS, n=10), Group III (GPT+JM, n=10). All groups were evaluated three times a week for 4 weeks. Pain was measured by visual analogue scale (VAS), CVA was measured using digital goniometer and autonomic system function (heart rate; HR, skin conductivity; SC, LF norm, HF norm, LF/HF ratio) was measured by Biofeedback ProComp Infiniti. After 4 weeks, paired t-test was used to compare the changes within the group and one way ANOVA was used to compare those between the groups. RESULTS: In Group I, VAS was significantly decreased. In Group II and III was a significantly change in all items. In comparison between Group I and II was a difference in all items except HR. In comparison between Group I and III was a difference in all items. In comparison between Group II and III was a difference in VAS, LF norm and LF/HF ratio. CONCLUSION: This study showed that SS and JM can effectively reduce pain and normalize the autonomic system function.

Study on Effects of Incense Smokes Composed with Oriental Medical Herbs on HRV and Stress Relaxation (한약재 훈법(熏法)의 심박변이도 및 스트레스 이완에 미치는 임상 효과)

  • Hwang, Chi-Hyuk;Kim, Kyoung-Shin;Uhm, Ji-Tae;Hwang, Seock-Yeon;Jo, Hyun-Kyung;Kim, Byoung-Soo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.4
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    • pp.566-571
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    • 2012
  • The purpose of this study was to assess the effects of herbs aroma on relaxation in highly stressed volunteers with heart rate variability(HRV) and SACL(stress arousal check list). 28 highly stressed volunteers participated in this study. The volunteers were examined with heart rate variability(HRV) and SACL(stress arousal check list) before and after smell herbs aroma. After smelling powder incense composed with oriental medicine herbs, mean RR, SDNN, LF, HF, TP were incresed and mean HRV, LF/HF ratio were decreased, but it was not significant. And VLF, norm HF were incresed and norm LF was decreased significantly. This results show that the powder incense composed with oriental medicine herbs effects on decresing sympathetic nervous activity and increasing parasympathetic activity and rebalancing autonomic nervous system who were under stress.