• Title/Summary/Keyword: Hrv

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An experimental study on the performance of the separate type heat pipe in accordance with the refrigerant charge (냉매 충진량에 따른 분리형 히트파이프 성능에 관한 실험적 연구)

  • Jeon, Sung-Taek;Cho, Jin-Pyo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1600-1604
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    • 2015
  • As modern houses are constructed with high-density and high-insulation, there is benefit to reduce energy consumption, but there are many side effects raised from polluted air. To solve the problem, a ventilation system is used to improve a indoor air quality. In this research, we experimentally estimate ventilation performance of HRV(heat recovery ventilator) with heat-pipe according to working fluid filling quantity and ventilation. Heat-pipe used in this study was designated separately to be applied to a ventilation system. The working fluid was R22, which was filled from 40 to 55 (%vol.) by 5(%vol.). Ventilation based on the front velocity was measured from 0.3 m/s to 1.5 m/s by 0.3 m/s intervals. Refrigerant filling quantity with the highest efficiency was found to depend on the ventilation. From this study the optimal refrigerant filling quantity in accordance with the ventilation of the detachable heat pipes was found experimentally.

A Study on Heart Rate Variabilities during Graded Head-up Tilt (점증적 틸트 각도 변화에 대한 심박변동에 관한 연구)

  • Jeong, K.S.;Shin, K.S.;Lee, J.W.;Choi, S.J.;Ahn, J.;Chon, J.S.;Lee, M.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.406-409
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    • 1997
  • In this paper, the power spectral analysis and fractral dimension analysis of heart rate variability(HRV) were performed to evaluate effects of orthostatic stress with head-up tilt on autonomic nervous system(ANS) for 24 young and healthy subjects(age: $24{\pm}5yr$.). The ECG and respiration signals were recorded at the tilt angle of $0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;70^{\circ}$ and $90^{\circ}$ successively for 5 minutes per each stage under the condition of frequency controlled respiration (0.25Hz). Heart rate(HR) gradually increased as the angle increased. Similarly, according to the increment of angle, normalized low frequency(LF) component(0.05-0.15Hz) gradually increased, whereas normalized high frequency(HF) component (0.20-0.30Hz) was reduced. From these results it is speculated that orthostatic stress, head-up tilt, results in the prevalence of sympathetic tone in autonomic balance with the increment of sympathetic tone and the decrement of parasympathetic tone, which seems to mean that autonomic nervous system plays a major role in compensating for disturbances of cardiovascular system due to it.

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Comparison Characteristic on Psychological Status between Genuine and Pseudo Halitosis (진성구취 및 가성구취 환자군의 심리적 특성차이에 대한 연구)

  • Jang, Seung-Won;Kim, Jin-Sung;Kang, Kyung;Kim, Ju-Yeon;Son, Ji-Yeong;Baek, Seung-Hwan;Choi, Jane;Ryu, Bong-Ha
    • The Journal of Internal Korean Medicine
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    • v.34 no.4
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    • pp.405-411
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    • 2013
  • Objectives : This study was designed to investigate the difference between genuine and pseudo halitosis about qi stagnation and stress. Methods : We recruited 63 halitosis patients who visited the halitosis clinic in the Kyung Hee University Korean Medicine Hospital from June 2012 to August 2013. We classified the halitosis patients into two groups, genuine and pseudo halitosis based on organoleptic assesment (OLT) score and evaluated the severity of self-reported halitosis using visual analog scale (VAS), amount of sulfide compounds using Halimeter, qi stagnation level using qi stagnation questionnaire and stress levels using heart rate variability (HRV) parameters. Results : Comparing the genuine halitosis group and the pseudo halitosis group, there was no significant difference in VAS of halitosis but significant difference in halimeter score. Distribution of qi stagnation and non-qi stagnation groups was significantly different between genuine and pseudo halitosis. Compared to the genuine halitosis group, the pseudo halitosis group showed a significant higher value of low frequency/high frequency ratio (LF/HF ratio). Conclusions : The result of this study suggest that there is significant difference about qi stagnation and stress level between genuine halitosis and pseudo halitosis patients, so when approaching pseudo halitosis patients, we should consider their psychological and emotional status.

A study on characteristics of the autonomic nervous system in students with Keongke - Using Heart Rate Variability and Pupil Size Variability - (경계(驚悸) 증상을 지닌 학생 집단의 자율 신경 기능 특성에 대한 연구 - 심박변이도와 동공크기 변이도를 중심으로 -)

  • Lee, Seung-Gi;Lee, Jeong-Chan;Kim, Ji-Eun;Park, Kyung-Mo;Kang, Hee-Chul
    • Journal of Oriental Neuropsychiatry
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    • v.17 no.2
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    • pp.133-145
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    • 2006
  • Objective : The purpose of this experimental-controlled study was to investigate the characteristics of the autonomic nervous system in students with Keongke by using HRV(Heart rate variability) and PSV(Pupil size variability). Method : The study group was consisted of 11 students with self recognition as the experimental group, and 25 normal students as the control group. Informations on gender and age were obtained by medical charts and personal interviews. By using heart rate variability and pupil size variability, we measured the value of HRT(Heart rate), SDNN(Standard deviation of NN intervals), LFnorm(Low frequency normalization), HFnorm(High frequency normalization), LF/HF ratio, Pupil area, B.S.(Basic size), C.R.(Max Constriction Rate) and 1s.d.(1sec Dilation Rate). I compared the degrees of the sympathetic and parasympathetic activity. Result : 1. In the result of heart rate variability between experimental and control group, none of the parameters of experimental group were significantly different from control group. And even though there were no statistical significance, there were some numerical differences in SDNN, LF norm, HF norm. 2. In pupil size variability, C.R. and 1s.d. of the experimental group were increased compared to control group. Conclusion : The study results suggest that the group with Keongke has differences of autonomic nervous system as compared to those in normal state. Measurement value of PSV is a new technical approach to estimate the autonomic nervous system.

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A Prospective Observational Study of Herbal Medicines on Depressive Disorder (우울장애 한약치료에 대한 전향적 관찰연구)

  • Kim, Ju Yeon;Kim, Hwan;Lee, Ji-Yoon;Jung, Jin-Hyeong;Yang, Changsop;Lee, Mi-Young;Jung, In Chul
    • Journal of Oriental Neuropsychiatry
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    • v.31 no.2
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    • pp.63-76
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    • 2020
  • Objectives: The purpose of this study was to verify the clinical effects of herbal medicines on patients with depressive disorder. Methods: A prospective observational study on patients with depressive disorder was conducted. The patients were treated with herbal medicines for eight weeks. The Korean Hamilton Depression Rating Scale (K-HDRS) was evaluated as the primary outcome and the Korean Beck's Depression Inventory (K-BDI), Instrument on Pattern Identification for Depression, Korean Symptom Checklist-95 (KSCL-95), Insomnia Severity Index (ISI), Korean State-Trait Anxiety Inventory (STAI-K), Korean State-Trait Anger Expression Inventory (STAXI-K), EuroQol five-dimensional Questionnaire (EQ-5D), Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Heart Rate Variability (HRV) were measured as the secondary outcome. Adverse events were assessed for safety. Results: A total of 35 participants were observed for 12 weeks. The K-HDRS improved significantly in four, eight, and 12 weeks and the K-BDI showed significant differences in four, and eight weeks. There were no significant improvements in other evaluation scales. Gyejibongnyeong-hwan was the most frequently and continuously prescribed, showing significant improvements of K-HDRS after eight weeks of treatment. Conclusions: In our observational study, herbal medicine was effective for relieving the depression of patients with depressive disorder and Gyejibongnyeong-hwan showed the most significant effectiveness.

Biological Change by Forest Healing according to Sasang Constitution : preliminary study (사상체질별 숲치유의 생체학적 변화 : 예비연구)

  • Hong, Sun-Gi;Choi, Eun-Ju;Sun, Seung-Ho;Choi, Ga-Young;Lee, Sun-Ju;Han, In-Sik;Lee, Jae-Hun;Yoo, Jun-Sang
    • Journal of Sasang Constitutional Medicine
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    • v.23 no.4
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    • pp.487-502
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    • 2011
  • 1. Objective This study was performed to research the biological change of forest healing according to Sasang constitution. 2. Methods Forty seven applicants are involved in this study. They were classified into three groups(Soyangin, Taeeumin, Soeumin) by QSCC II. And then they participated in forest healing program from March 26 to March 27 in 2011. We performed before and after experiment, including vital sign, electroencephalography(EEG), heart rate variability(HRV), complete blood cell count(CBC), biochemical test(BC), and stress hormones. 3. Results Men had the relaxative effect of tension. While, the group of women and Soyangin was more sensitive to sudden environmental change than the group of men or other constitutions. The tension of women and soyangin's group increased after the forest healing program. Soeumin group showed reduced diastolic blood pressure after the forest healing program. 3. Conclusions Forest healing program has shown better efficacy in relaxation in men than women, in lowering diastolic blood pressure in Soeumin group than other constitutional groups. However a single positive result within this study should be carefully interpreted.

Research in Physiology Signal Change of Thermal-Comfort Evaluation by Air Conditioner Temperature Change (에어컨 온도변동에 따른 온열쾌적감 평가 및 생리신호 변화에 관한 연구)

  • Kim, Hyung-Chul;Kum, Jong-Su;Shin, Byeong-Hwan;Chung, Yong-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.18 no.1
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    • pp.11-18
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    • 2006
  • Man has always striven to create a thermally comfortable environment. This is reflected in building traditions around the world - from ancient history to present day. Today, creating a thermally comfortable environment is still one of the most important parameters to be considered when designing buildings. It is defined in the ISO 7730 standard as being "That condition of mind which expresses satisfaction with the thermal environment". A definition most people can agree on, but also a definition is not easily converted into physical parameters. Thermal comfort is a matter of many physical parameters, and not just one, as for example the air temperature that is set by air-conditioner. The most important matter Today's common offices and homes are only depending on air-conditioning as a cooling system during the summer. This kind of system tends to be focused on the person who controls it and those who are around the air-conditioner while thermal-comfort is neglected. Futhermore, the people's body conditions are not considered during each time that beginning, middle, last of the air-conditioning which causing displeasure of the residents more and more. This kind of operating system is set for a long time may causes unbalanced air condition and man's psychologic displeasure goes to increase.

Integration of Application Program for Dementia Diagnosis using Biometric Sensor and Oxygen Chamber (생체센서를 이용한 치매진단용 어플리케이션 프로그램과 산소챔버의 융합)

  • Cho, Myeon-Gyun;Choi, Hyo Sun;Kim, Hyeong-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5847-5855
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    • 2013
  • The purpose of this research is to develop Dementia-diagnosis application program through inter-working between biometric sensors and smart phone with diagnostic programs. Receiving data from 2 biometric sensors, SpO2 and HRV(heart rate variability) with Bluetooth and adding scores from questionnaires and memory test game, smart phone can draw a final Dementia Index(DI). Simple clinical tests provided threshold for Dementia, and diagnosis was made by comparing the DI with the threshold. We performed testing on persons aged over 60 and found out the proposed application can be used to diagnose Dementia easily and quickly. Additionally, we have shown the potential of oxygen chamber combined with Dementia-diagnosis application as a medical equipment to ease or cure Dementia in its early stages.

The Effect of a Target Controlled Infusion of Low-Concentration Ketamine on the Heart Rate Variability of Normal Volunteers (정상인 자원자에서 목표농도조절주입법으로 투여한 저농도의 케타민이 심장박동수변이도에 미치는 영향)

  • Jung, Jai Yun;Lee, Jun Ho;Lee, Jeong Seok;Kim, Yong Ik
    • The Korean Journal of Pain
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    • v.22 no.1
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    • pp.39-46
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    • 2009
  • Background: Ketamine has an indirect sympathetic stimulation effect. We investigated heart rate variability (HRV) as a marker of cardiac autonomic function after a target controlled infusion (TCI) of ketamine with a plasma concentration of 30 or 60 ng/ml. Methods: In 20 adult volunteers, the mean of the R wave to the adjacent R wave interval (RRI), the range of RRI, the root mean square successive difference of intervals (RMSSD), the total power, the low frequency (LF, 0.04-0.15 Hz) power, the high frequency (HF, 0.15-0.4 Hz) power, the normal unit HF (nuHF), the normal unit LF (nuLF), the LF/HF ratio and the SD1 and the SD2 in the Poincare plot were measured before and after a TCI of ketamine. We observed for any psychedelic symptoms or sedation. Results: There were no differences in the mean and range of the RRI, RMSSD, total power, LF power, HF power, nuHF, nuLF, LF/HF ratio, SD1 and SD2 between before and after ketamine administration. The OAA/S score was higher and there were more psychedelic symptoms with a 60 ng/ml plasma concentration than with a 30 ng/ml plasma concentration. Conclusions: This study did not show any effect of a low plasma concentration of ketamine on the autonomic nervous system.

Effect of a Diet Program for Adult Women on Body Weight Loss and Health Related Indices (다이어트 프로그램이 성인여성의 체중감량과 건강관련지수에 미치는 효과)

  • Park, Heejung;Cho, Seongkyung;Koo, Jea Ok
    • Korean Journal of Community Nutrition
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    • v.18 no.6
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    • pp.599-610
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    • 2013
  • This study was carried out to analyze the effect of a diet program for adult women on weight loss, BMI, eating habits, sleeping habits, health related indices. The subjects was 415 participants of the 10 weeks (20 time participation program). The data was collected by basic somatometry and HRV (Heart Rate Variability) / APG (Accelerated Plethysmograph) Analyzer. The average age, height, weight and BMI were 28.6 years, 162.1 cm, 62.8 kg and 23.9 $kg/m^2$, respectively. Their body types by BMI were under weight (1.2%), normal (45.8%), overweight (24.8%), mild obesity (22.7%) and obesity (5.5%). There were significant reductions of average weight (4.6 kg) and average BMI (1.75 $kg/m^2$) on the 10th week. There were positive changes in vascular age (50.4%), stress index (44.6%), fatigue index (43.9%), health index (54.5%) of the subjects during the program. There was a meaningful difference of the average variation for the vascular age, stress index, fatigue index, and health index between two groups; one improving the eating habit and the other did not (p<0.05), and also there was a meaningful difference of the average variation for the fatigue index in both groups improving the sleeping habit (p<0.05), but was not a meaningful difference of the average variation for the vascular age, stress index, and health index between two groups. There was a meaningful difference of the average variation for the vascular age, stress index, fatigue index, and health index between two groups improving both eating and sleeping habit (p<0.05). In conclusion, the weight loss program was effective on the weight loss and BMI reduction and health related indices.