• Title/Summary/Keyword: LF(Low Frequency)

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Study of the Relation of Autonomic Nerve System and Peripheral Facial Palsy by the Heart Rate Variability (HRV(Heart Rate Variability)를 통한 말초성 안면신경마비와 자율신경실조의 상관성 연구)

  • Hwang, Gee-Hwae;Hwang, Jong-Soon;Cho, Hyun-Seok;Kim, Kyung-Ho;Kim, Kap-Sung;Lim, Dae-Jung
    • Journal of Acupuncture Research
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    • v.22 no.6
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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.

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The Change of Heart Rate Variability in Anxiety Disorder after Given Physical or Psychological Stress (불안장애 환자에서 육체적 및 정신적 스트레스 시 심박변이도의 변화)

  • Cho, Min-Kyung;Park, Doo-Heum;Yu, Jaehak;Ryu, Seung-Ho;Ha, Ji-Hyeon
    • Sleep Medicine and Psychophysiology
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    • v.21 no.2
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    • pp.69-73
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    • 2014
  • Objectives: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress in anxiety disorder patients. Methods: HRV was measured at resting, upright, and psychological stress states in 60 anxiety disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity. Differences between HRV indices were evaluated using paired t-tests. Gender difference analysis was accomplished with ANCOVA. Results: SDNN (Standard deviation of normal RR intervals) and low frequency/high frequency (LF/HF) were significantly increased, while NN50, pNN50, and normalized HF (nHF) were significantly decreased in the upright position compared to resting state (p < 0.01). SDNN, root mean square of the differences of successive normal to normal intervals, and LF/HF were significantly increased, while nHF was significantly decreased in the psychological stress state compared to resting state (p < 0.01). SDNN, NN50, pNN50 were significantly lower in upright position compared to psychological stress and nVLF, nLF, nHF, and LF/HF showed no significant differences between them. Conclusion: The LF/HF ratio was significantly increased after both physical and psychological stress in anxiety disorder, but did not show a significant difference between these two stresses. Significant differences of SDNN, NN50, and pNN50 without any differences of nVLF, nLF, nHF, and LF/HF between two stresses might suggest that frequency domain analysis is more specific than time domain analysis.

The Effects of Manual Passive Exercise Performed by Physical Therapists on Autonomic Nervous System (물리치료사에 의해서 실시되는 도수수동 운동이 자율신경계에 미치는 영향)

  • Kim, In-Bae;Kim, Chung-Yoo;Kim, Eun-Kyung;Shin, Han-Ki;Kang, Jong-Ho
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.1
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    • pp.9-14
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    • 2015
  • PURPOSE: The purpose of this study was to investigate the effects of ten minutes of manual passive exercise performed by physical therapists on autonomic nervous system. METHODS: Thirty-five healthy adults, both male and female, were chosen as subjects for this study. The autonomic nervous system was measured by heart rate variability (HRV),before and after passive exercise using the following measurements: mean heart rate (mean HRT), low frequency (LF) and high frequency (HF) components, the LF/HF ratio, root mean square of the successive differences (RMSSD), and the HRV index. The exercise was performed on the subjects by a physical therapist with seven years of experience specializing in the nervous system. The exercise was conducted at the mid-range of motion on the upper and lower limbs of the subjects for two minutes and thirty seconds and for a total of ten minutes. RESULTS: There was a significant increase in the LF component. The mean HRT and the LF/HF ratio both increased, but these increases were not significant. The HF component, RMSSD, and HRV index all decreased, but these decreases were not significant. CONCLUSION: In conclusion, mid-range manual passive exercise does not induce stress on the autonomic nervous system. It can safely be performed by a physical therapist.

Relationship between Vestibuloocular Reflex and Autonomic Nerve Response in Adults (성인에서 전정안구반사를 이용한 평형감각과 자율신경반응의 관련성)

  • 김규겸;박현영;전희정;윤상대;박병림
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1999.03a
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    • pp.237-242
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    • 1999
  • The nature of the interactions between the vestibular and autonomic systems is complex and has not been fully defined. Vestibuloocular reflex induced by sinusoidal rotation and activity of the autonomic nerves in the heart were measured to investigate the interactions between the vestibular system and the autonomic nervous system in healthy adults. Eye movement induced by sinusoidal rotation of the whole body or optokinetic stimulation at 0.04 Hz was analyzed in gain, phase, and symmetry. EKG was measured during vestibular stimulation and analyzed in heart rate variability including mean R-R interval, standard deviation (SD) and coefficient of variance (CV) of R-R interval, and power spectrum of low frequency region (LF) and high frequency region (HF). Gain of eye movement was 0.65${\pm}$0.03 by ratatory stimulation, 0.70${\pm}$0.02 in optokinetic stimulation, 0.08${\pm}$0.02 in visual suppression, and 0.84${\pm}$0.04 in visual enhancement. In R-R interval, resting condition (control) was 0.82${\pm}$0.03 sec, and visual suppression showed significant increase and visual enhancement did significant decrease compared with control (p<0.01).CV was 0.06${\pm}$0.02 in control and visual enhancement increased significantly (p<0.05). In LF/HF control was 1.40${\pm}$0.23, which was not different from rotatory or optokinetic stimulation. But visual suppression decreased LF/HF significantly and visual enhancement increased significantly compared with control (p<0.01). These results suggest that degree of gain corresponds with LF/HF and increased gain in visual enhancement is deeply related to the activity of sympathetic nerves.

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Correlation Study between Electrogastrography and Heart Rate Variability in Dyspeptic Patients (소화불량 환자에서 위전도 검사와 HRV 검사와의 연관성 연구)

  • Kim, So-Yeon;Han, Chang-Woo;Park, Seong-Ha;Kwon, Jung-Nam;Lee, In;Hong, Jin-Woo;Choi, Jun-Yong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.4
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    • pp.532-538
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    • 2012
  • The aim of this study was to find correlation between EGG and HRV parameters in dyspeptic patients. 39 patients (male 8, female 31) were enrolled. EGG and HRV was measured in all patients. EGG parameters like % of gastric slow wave and power ratio were used to classify patients as normal or abnormal EGG groups. HRV parameters which were included TP (total power), LF(low frequency density), HF (high frequency density), and LF/HF ratio were compared between them. EGG parameters were compared among normal, sympathetic hyperactivity, and parasympathetic hyperactivity groups classified by LF/HF ratio. There was no difference in HRV parameters between normal and abnormal EGG groups. Comparing EGG parameters among normal, sympathetic hyperactivity, and parasympathetic hyperactivity groups, both sympathetic and parasympathetic hyperactivity groups had lower value of postprandial regularity of gastric slow wave than normal group. Abnormal value of LF/HF ratio(both sympathetic and parasympathetic hyperactivity) may be related with disturbance of electrical gastric activity in patients with dyspepsia.

Correlation between HRV and Bowel Sound Parameters in the Evaluation of Gastrointestinal Parasympathetic Nerve Activity from Patients with Functional Dyspepsia (기능성 소화불량증에서 위장관 미주신경 활성 평가를 위한 심박변이지표와 장음지표의 상관성 연구)

  • Kim, So-Yeon;Yoon, Sang-Hyub
    • The Journal of Internal Korean Medicine
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    • v.30 no.1
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    • pp.173-180
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    • 2009
  • Objectives : The aim of this study was to investigate the evaluation of gastrointestinal parasympathetic nerve activity by comparing between HRV and bowel sound parameters in patients with functional dyspepsia. Methods : 62 patients (male 22, female 40) were enrolled. HRV was measured in all patients. and TP (total power), LF (low frequency density: 0.04$\sim$0.15Hz), HF (high frequency density: 0.15$\sim$0.4Hz). and LF/HF ratio were analyzed. HF band is a reflection of parasympathetic activity. and the LF-to-HF ratio is considered a marker of sympathovagal balance. Bowel sounds were recorded at the day after, and postprandial %BS was used to indicate the gastric vagal activity after eating. HRV and bowel sound parameters were compared. and correlation between them was analyzed. Results : There was no difference in LF/HF ratio between patient group and healthy group of other report. According to values of %BS, each patient was classified into a normal (>6 %BS) or hypoactivity (<6 %BS) of gastric vagus nerve group. HF component of the hypoactivity group was not significantly higher than that of the normal group. There was no correlation between HRV and bowel sound parameters. Conclusions : Because no correlation was found between HRV and bowel sound parameters in patients with functional dyspepsia, we concluded that it is not proper to evaluate gastric vagus nerve activity by HRV measurement.

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Optimization of Etching Profile in Deep-Reactive-Ion Etching for MEMS Processes of Sensors

  • Yang, Chung Mo;Kim, Hee Yeoun;Park, Jae Hong
    • Journal of Sensor Science and Technology
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    • v.24 no.1
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    • pp.10-14
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    • 2015
  • This paper reports the results of a study on the optimization of the etching profile, which is an important factor in deep-reactive-ion etching (DRIE), i.e., dry etching. Dry etching is the key processing step necessary for the development of the Internet of Things (IoT) and various microelectromechanical sensors (MEMS). Large-area etching (open area > 20%) under a high-frequency (HF) condition with nonoptimized processing parameters results in damage to the etched sidewall. Therefore, in this study, optimization was performed under a low-frequency (LF) condition. The HF method, which is typically used for through-silicon via (TSV) technology, applies a high etch rate and cannot be easily adapted to processes sensitive to sidewall damage. The optimal etching profile was determined by controlling various parameters for the DRIE of a large Si wafer area (open area > 20%). The optimal processing condition was derived after establishing the correlations of etch rate, uniformity, and sidewall damage on a 6-in Si wafer to the parameters of coil power, run pressure, platen power for passivation etching, and $SF_6$ gas flow rate. The processing-parameter-dependent results of the experiments performed for optimization of the etching profile in terms of etch rate, uniformity, and sidewall damage in the case of large Si area etching can be summarized as follows. When LF is applied, the platen power, coil power, and $SF_6$ should be low, whereas the run pressure has little effect on the etching performance. Under the optimal LF condition of 380 Hz, the platen power, coil power, and $SF_6$ were set at 115W, 3500W, and 700 sccm, respectively. In addition, the aforementioned standard recipe was applied as follows: run pressure of 4 Pa, $C_4F_8$ content of 400 sccm, and a gas exchange interval of $SF_6/C_4F_8=2s/3s$.

Change of Heart Rate Variability in Depressive Disorder after Physical or Psychological Stress (우울장애 환자에서 육체적 및 정신적 스트레스 시 심박변이도의 변화)

  • Lee, Jong-Hwa;Yu, Jaehak;Ryu, Seung-Ho;Ha, Ji-Hyeon;Jeon, Hong-Jun;Park, Doo-Heum
    • Sleep Medicine and Psychophysiology
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    • v.25 no.1
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    • pp.15-20
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    • 2018
  • Objectives: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress states in depressive disorder patients. Methods: HRV was measured at resting, upright, and psychological stress states in 62 depressive disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity, respectively. Differences between HRV indices and VAS score were evaluated using paired t-tests. Gender difference analysis was conducted with ANCOVA. Results: SDNN (standard deviation of normal to normal intervals), LF/HF (low frequency/high frequency), and VLF (very low frequency) were significantly increased, while NN50 and pNN50 were significantly decreased in the upright position compared to resting state. SDNN, RMSSD (root mean square of the differences of successive normal to normal intervals), and VLF were significantly increased, while pNN50 was significantly decreased in the psychological stress state compared to resting state. SDNN, NN50, and pNN50 were significantly lower in an upright position compared to a state of psychological stress, and LF, HF, and LF/HF showed no significant differences Conclusion: The LF/HF ratio was significantly increased after physical stress in depressive disorder. However, the LF/HF ratio was not significantly increased after psychological stress, and the change in LF/HF ratio after physical stress and psychological stress did not significantly differ from each other. Significant increase in SDNN, NN50, and pNN50 in an upright posture compared to psychological stress suggests that depressive patients react more sensitively to physical stress than psychological stress.

A Pilot Study about The Effect of Chunwangbosim-dan(天王補心丹) on Heart Rate Variability of Healthy Subjects (천왕보심단이 정상인의 심박변이도에 미치는 영향에 대한 예비연구)

  • Kang, Rae-Yeop;Kim, Hyun-Jin;Han, Hyo-Jung;Park, Eun-Young;Jang, Jeong-A;Seo, Ho-Seok;Kim, Jin-Won;Kang, Hyun-Sun;Kim, Jee-Hoon;Cho, So-Hyun
    • Journal of Oriental Neuropsychiatry
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    • v.20 no.4
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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.

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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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