• 대한한의진단학회지
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• 제12권2호
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• pp.74-83
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• 2008

Background and purpose : Health is characterized by variability, and the loss of variability is associated with aging and disease. Normal healthy respiratory patterns are characterized by breath to breath variability. Cold-Heat scores are quantified indices in Korean Medicine. The aim of this study is to analyze relations between 9 respiratory indices (including breath to breath variability) and HRV(heart rate variability). Method : Respiratory data were measured during a period of 15 minutes and transferred to text file. We calculated 9 respiratory parameters using MATLAB 7.1. Afterwards we did correlation analysis of the 9 respiratory indices and HRV. Results and conclusion : Respiratory variability showed significant correlation with HRV.

• 대한한의진단학회지
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• 제12권2호
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• pp.84-95
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• 2008

Background and purpose: Health is characterized by variability and a loss variability is associated with aging and disease. Normal healthy respiratory patterns are characterized by breath to breath variability. The aim of this study is to analyze Correlation Analysis of 10 respiratory indices(include breath to breath variability) and K-POMS factors score. Method: Respiratory data were measured during 15 minutes and transferred to text file. We calculated 10 respiratory parameters in use of MATLAB7.1. After then do correlation analysis of 10 respiratory indices and K-POMS factors score. Result and conclusion: Respiratory variability is showed significant correlation with vigor factor. Respiratory rate is showed significant correlation with depression factor.

• 동의신경정신과학회지
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• 제27권2호
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• pp.89-101
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• 2016

Objectives In human, there is a diversity in the breathing pattern, for instance inspiratory and expiratory time, volume, breathing frequency, and breath-to-breath variation. Expecially, respiratory variability can provide important information about breathing regulation and physiological flexibility. it is significant to not only breathing index but also physiological index.Methods Thus this paper reviews the literature on respiratory variability with the aim of clinical application.Results We could find the interrelationships and respiratory variability between emotions, psychopathy, sighing, mental and physical activity.Conclusions As a result, respiratory variability can serve an important physiological index in the clinical area and reflects how our bodies act in diverse environments under various condition.

• 대한한의진단학회지
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• 제12권2호
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• pp.96-106
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• 2008

Background and purpose : Health is characterized by variability and a loss variability is associated with aging and disease. Normal healthy respiratory patterns are characterized by breath to breath variability. Cold-Heat score are quantified indices in Korean Medicine. The aim of this study is to analyze relations between 9 respiratory indices (including breath to breath variability) and cold-heat score by questionnaire. Method : Respiratory data were measured during 15 minutes and transferred to text file. We calculated 9 respiratory parameters in use of MATLAB7.1. After then we did correlation analysis of 9 respiratory indices and cold-heat score Results and conclusion : EIratio is showed significant correlation with Cold score and weighted Heat score.

• 정신신체의학
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• 제14권1호
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• pp.33-38
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• 2006

건강한 사람들은 복잡한 양상의 심박동수 변이 (Heart rate variability, 이하 HRV)를 보이는데, 이것은 생체의 항상성 유지를 위한 반응을 반영한다. 0.1Hz 내외의 속도로 호흡하도록 바이오피드백 훈련을 하면 호흡 동성 부정맥(Respiratory sinus arrhythmia, 이하 RSA)이 극대화되면서 심박동수 변이의 강도가 증가한다. 이러한 효과를 극대화하려면 압반사계에 의해 자연스럽게 발생하는 것으로 추정되는 리듬과 호흡동성 부정맥(RSA)사이의 동조가 일어나는 지점까지 호흡 속도를 늦춰야 한다. 기구를 이용한 바이오피드백 훈련을 통해 각자에게 알맞은 최적의 호흡 속도를 찾을 수 있다. 본고에서는 RSA 바이오피드백 원리에 따른 훈련 과정과 지침을 요약하여 제시하였다.

• 대한통합의학회지
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• 제6권2호
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• pp.17-23
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• 2018

Purpose : The purpose of this study was to investigate whether the respiratory cycle and posture can modulate the autonomic nervous system. Methods : Thirty-two healthy men and women, aged 20-30 years, were enrolled in this study. We conducted 2-second and 6-second respiratory cycle with the subjects in standing, sitting, and supine positions, respectively. Their heart rate variability was measured in each position for both cycle lengths. Results : The low frequency/high frequency (LF/HF) ratio is derived from heart rate variability. In the 2-second respiratory cycles, the LF/HF ratios were highest in standing, sitting, and supine position in descending order. There was a significant difference in heart rate between standing and sitting positions (P<.005). In addition, there was a significant difference in heart rate between standing and supine position (P<.000). In the 6-second respiratory cycles, the LF/HF ratios were again highest in a standing, sitting, and supine position in descending order. However, posture was not found to make a significant difference in this case. Conclusion : Respiratory cycle and posture effectively modulated the autonomic nervous system. Further studies of the clinical application of these results should be conducted.

• 대한의용생체공학회:의공학회지
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• 제34권3호
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• pp.105-110
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• 2013

Respiratory signal is one of the important physiological information indicating the status and function of the body. Recent studies have provided the possibility of being able to estimate the respiratory signal by using a change of PWV(pulse width variability), PRV(pulse rate variability) and PAV(pulse amplitude variability) in the PPG (photoplethysmography) signal during daily life. But, it is not clear whether the respiratory monitoring is possible even during sleep. Therefore, in this paper, we estimated the respiration from PWV, PRV and PAV of PPG signals during sleep. In addition, respiration rates of the estimated respiration signal were calculated through a time-frequency analysis, and errors between respiration rates calculated from each parameter and from reference signal were evaluated in terms of 1 sec, 10 sec and 1 min. As a result, it showed the errors in PWV(1s: $36.38{\pm}37.69$ mHz, 10s: $36.53{\pm}38.16$ mHz, 60s: $30.35{\pm}38.72$ mHz), in PRV(1s: $1.45{\pm}1.38$ mHz, 10s: $1.44{\pm}1.37$ mHz, 60s: $0.45{\pm}0.56$ mHz), and in PAV(1s: $1.05{\pm}0.81$ mHz, 10s: $1.05{\pm}0.79$ mHz, 60s: $0.56{\pm}0.93$ mHz). The errors in PRV and PAV are lower than that of PWV. Finally, we concluded that PRV and PAV are more effective than PWV in monitoring the respiration in daily life as well as during sleep.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.257-264
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• 2020

Objective: To investigate test-retest reliability and responsiveness of Equivital Lifemonitor and photoplethysmography based wristwatch tools in assessing physiological parameters during a simulated fatigue task. Methods: Ten university students (Mean age, 30.6 ± 1.7 years) participated in this pilot study. Participants were asked to perform a 30-minute of a simulated fatigue task in an experimental setup in a lab. The physiological parameters (e.g., heart rate, heart rate variability, respiratory rate, electrodermal activity, and skin temperature) were measured at baseline and immediately after the fatigue task. An intraclass correlation coefficient (ICC2,1) was used to evaluate the test-retest reliability of each tool in assessing physiological measures. In addition, the responsiveness of each tool to measure changes from baseline to posttest was calculated using a standardized response mean. Results: The Equivital Lifemonitor has shown good to excellent test-retest reliability for the assessment of heart rate (ICC, 0.97), heart rate variability (ICC, 0.86), respiratory rate (ICC, 0.77), and local skin temperature (ICC, 0.76). However, photoplethysmography based wristwatch showed moderate to good test-retest reliability for the assessment of heart rate (ICC, 0.71), heart rate variability (ICC, 0.73), electrodermal activity (ICC, 0.80), and skin temperature (ICC, 0.72). A large standardized response mean (>0.8) indicates that both tools can capture the changes in heart rate, heart rate variability, respiratory rate, skin temperature, and electrodermal activity after a 30-minute of fatigue task. Conclusions: The Equivital Lifemonitor and photoplethysmography based wristwatch devices are reliable in measuring physiological parameters after the fatigue task. Additionally, both devices can capture the fatigue response after a simulated construction task. Future field studies with a larger sample should investigate the sensitivity and validity of these tools in measuring physiological parameters for fatigue assessment at construction sites.

• 대한인간공학회지
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• 제35권5호
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• pp.371-381
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• 2016

Objective:This study aims to evaluate the features of heart rate variability (HRV) and respiratory signals as indices for a driver's drowsiness and waking status in order to develop the classification model for a driver's drowsiness and waking status using those features. Background: Driver's drowsiness is one of the major causal factors for traffic accidents. This study hypothesized that the application of combined bio-signals to monitor the alertness level of drivers would improve the effectiveness of the classification techniques of driver's drowsiness. Method: The features of three heart rate variability (HRV) measurements including low frequency (LF), high frequency (HF), and LF/HF ratio and two respiratory measurements including peak and rate were acquired by the monotonous car driving simulation experiments using the photoplethysmogram (PPG) and respiration sensors. The experiments were repeated a total of 50 times on five healthy male participants in their 20s to 50s. The classification model was developed by selecting the optimal measurements, applying a binary logistic regression method and performing 3-fold cross validation. Results: The power of LF, HF, and LF/HF ratio, and the respiration peak of drowsiness status were reduced by 38%, 22%, 31%, and 7%, compared to those of waking status, while respiration rate was increased by 3%. The classification sensitivity of the model using both HRV and respiratory features (91.4%) was improved, compared to that of the model using only HRV feature (89.8%) and that using only respiratory feature (83.6%). Conclusion: This study suggests that the classification of driver's drowsiness and waking status may be improved by utilizing a combination of HRV and respiratory features. Application: The results of this study can be applied to the development of driver's drowsiness prevention systems.

• 대한한의진단학회지
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• 제11권1호
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• pp.146-156
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• 2007

1. The effect of variations in inspiration and expiration times on heart rate variability was studied in 78 healthy subjects (mean age $24.35{\pm}1.92$ years; 47 male) between regulated respiration group and normal respiration group as the control group. 2. The control group followed normal respiration pattern, whereas the regulated group followed three types of respiration pattern. The first pattern was long respiration(E/I ratio 1.6:1), the second pattern was short inspiration followed by long expiration (SILE), and the last pattern was long inspiration followed by short expiration(LISE). The average expiration/inspiration time ratios of SILE and LISE were 1.0 and 3.4, respectively. The respiration rate in the regulated group was approximately 10 cycles/min. 3. Respiration rate and tidal volume are respiratory variables known to modulate RSA. The results of the present study indicate that RSA can also be modulated by a third respiratory variable, the expiration/inspiratory time ratio. In this study, LF, HF, RSA, VLF is increased the most in LISE group compared to the other groups. HF and RSA increased significantly in the long respiration rate and SILE groups. However LF and VLF, which reflects the sympathetic tones, did not increase as much as the LISE group.