• Journal of People, Plants, and Environment
• /
• v.24 no.5
• /
• pp.545-550
• /
• 2021

Background and objective: With increasing land use intensity in urban areas, apartment buildings have been recognized as a typical type of urban residence. In this study, the impacts of different views through a window on health-related responses were investigated using psychological and physiological parameters. Methods: Photos of three different types of views taken on low (2-12 m), middle (28-35 m), and high (over 54 m) floors of dense apartment building areas were used as visual stimuli. Twenty-two healthy adults participated in the indoor experiment. Semantic differential methods and profile of mood states were used as psychological tools. Autonomic nervous activity was evaluated using blood pressures, pulse rate and heart rate variability (HRV). Results: Analytic data showed different characteristics of psychological and physiological outcomes in three different apartment views. In the analysis of psychological parameters, significantly negative responses to the views on middle floors were found in the subscales of tension-anxiety and anger-hostility, compared to low floors. Significantly positive scores in the subscale of vigor were found on low floors with abundance of vegetation and high floors with a view of the sky. A significantly increased value of HF was found on low floors (2,294.96 ± 169.79), compared to the middle(1,553.45 ± 84.66) and high (1,523.02 ± 70.49) floors. Despite the high scores in openness and vigor, high floor views showed significantly higher LF/HF values (1.83 ± 0.09), the indicator of the sympathetic nervous system, than low (1.30 ± 0.07) and middle floor views (1.34 ± 0.06), which might be related to the unconscious fear of heights. Conclusion: Views from different heights in an apartment building can affect the psychological states of residents. Green space through the window may have a positive health outcome by reducing physiological stress.

• Journal of Digital Policy
• /
• v.2 no.4
• /
• pp.25-32
• /
• 2023

This paper is a study to develop a deep neural network (DNN) blood glucose prediction model based on heart rate (HR) and heart rate variability (HRV) data measured by PPG-based sensors. MLP deep learning consists of an input layer, a hidden layer, and an output layer with 11 independent variables. The learning results of the blood glucose prediction model are MAE=0.3781, MSE=0.8518, and RMSE=0.9229, and the coefficient of determination (R²) is 0.9994. The study was able to verify the feasibility of glycemic control using non-blood vital signs using PPG-based digital devices. In conclusion, a standardized method of acquiring and interpreting PPG-based vital signs, a large data set for deep learning, and a study to demonstrate the accuracy of the method may provide convenience and an alternative method for blood glucose management in dogs.

• Science of Emotion and Sensibility
• /
• v.14 no.4
• /
• pp.653-662
• /
• 2011

As technology in 3D industry has rapidly advanced, a lot of studies primarily focusing on visual function and cognition have become vigorous. However, studies on effect of 3D visual fatigue on autonomic nervous system have not less been conducted. Thus, this study was to identify and determine the effect that might have a negative influence on sympathetic nervous system, parasympathetic nervous system, and cardiovascular system. Fifteen undergraduates (female: 9, mean age: $22.53{\pm}2.55$) participated and were sat on a comfortable chair, viewing a 3D content during about 1 hour. Cardiac responses like SDNN(standard deviation of RR intervals), RMS-SD(root mean squared successive difference), and HF/LF ratios extracted from the measured PPG(Photo-PlethysmoGram) before viewing 3D were compared to those after viewing 3D. The results showed that after subjects watched the 3D, responses in sympathetic nervous system and parasympathetic nervous system were activated and deactivated, respectively relative to those before watching the 3D. The results showed that HF/LF ratio, Ln(LF), and Ln(HF) after viewing 3D were significantly reduced relative to those before viewing 3D. No significant effects were observed in SDNN and RMS-SD. Results obtained in this study showed that visual fatigue induced by watching 3D adversely influenced autonomic nervous system, and thereby reduced heart rate variability causing sympathetic nervous acceleration.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.24 no.3
• /
• pp.525-532
• /
• 2010

Dypepsia is the most common gastrointestinal disease and mainly occurs by stress or food. According to the cause of dyspepsia, the clinical characteristics and the curative process are different in patients. The purpose of this study is to compare acute dyspepsia patients depending on food factor and stress factor. For this study, we analyzed the cause, and the symptoms of 59 acute dyspepsia patients and divided them into two groups: one group is 27 acute dyspepsia patient group caused by stress factor (stress factor group). The other group is 32 acute dyspepsia patient group caused by food factor (food factor group). In addition, we carried out HRV test and compared HRV index between two groups. There was no significant difference in past illness involved in gastrointestinal tract diseases between two groups. There were big differences in the frequency of chest discomfort, thurst, lack of appetite, and exhaustion after meals between two groups. There were many changes of tongue fur in food factor group. But there were many changes of tongue body in stress factor group. The pulse pattern is mostly wiry in stress factor group. But, The pulse pattern is mostly slippery in food factor group. HF, TP were significantly lower than food factor group in stress factor group, it means autonomic nerve system was more suppressd in stress factor group than food factor group. Food factor group improved sooner than stress factor group. This study presented the clinically different characteristics (past medical history, symptoms, tongue diagnosis, pulse pattern, curative process) of acute dyspepsia depending on food factor and stress factor. Thus, it provides the necessity of oriental medical diagnosis and treatment called pattern identification for acute dyspepsia.

• Science of Emotion and Sensibility
• /
• v.18 no.3
• /
• pp.63-70
• /
• 2015

This study identified heart response of participants while listening to sounds which have 1/f fluctuations with exponent ${\alpha}$ gradient. The participants were engaged in emotional stress work. Prior studies related to 1/f fluctuation sound have reported that sound source can alleviate psychological and physiological state of users. Subjects of this study were exposed to sound with three levels of ${\alpha}$ gradient. Heart response of subjects were measured with Photoplethysmography(PPG) sensor simultaneously. The dependent variables of this study were beat per minute(BPM), very low frequency percent of pulse rate variability (VLF percent), the standard deviation of all normal RR intervals (SDNN), and high frequency power(HF power). Subject showed arousal response when exposed to sound with exponent ${\alpha}$ gradient of 3 whereas the sound with exponent ${\alpha}$ gradient of 1 and 2 resulted in relax effect. The characteristic of 1/f fluctuation sounds can be applied to alleviate stress for employers under emotional labor.

• Science of Emotion and Sensibility
• /
• v.4 no.2
• /
• pp.79-88
• /
• 2001

The objectives of this study were to investigate the relationship of sound parameters with subjective sensation and physiological responses, and to figure out the interrelationship between the subjective sensation and physiological responses. Sound parameters calculated were LPT, ΔL, Δf, loudness[Z], and sharpness[Z]. Subjective sensation was evaluated in 7 aspects(soft-hard, loud-quiet, pleasant-unpleasant, sharp-dull, clear-obscure, rough-smooth, high-low) by thirty participants. We acquired physiological responses when each fabric sound was presented to 10 participants. Physiological signals obtained in this study were electroencephalogram(EEG), pulse volume(PV), skin conductance level(SCL), and LF/HF of heart rate variability. The larger the values of loudness[Z] and LPT, the louder and the rougher the subjective sensation of the perceived fabric sound. Also, the larger the values of loudness[Z] and LPT, the harder, the duller, and the less pleasant. As LPT increased, PV decreased. Loudness[Z] increased in proportion to SCL and so did sharpness[Z] to LF/HF. As the sound perceived to be quieter and clearer, the relative power of slow alpha rose. As the sound perceived to be more pleasant and smoother, PV rose.

• Journal of Biomedical Engineering Research
• /
• v.35 no.4
• /
• pp.75-80
• /
• 2014

This paper proposed a method that can automatically classify sleep apnea by using features extracted from pulse rate variability(PRV) signals induced from piezo snoring sensor for patients with obstructive sleep apnea(OSA). We have extracted eight features(NN, SDNN, RMSSD, NN10, NN50, LF, HF and LF/HF ratio) based on time and frequency analyses of PRV. Sleep apnea was classified by a linear discriminant analysis(LDA). A performance was evaluated using snore recordings from 13 patients with OSA (ages: $54.5{\pm}10.5$ years, body mass index: $26.3{\pm}2.5kg/m^2$, apnea-hypopnea index: $19.2{\pm}6.0/h$). The sensitivity and specificity were $78.9{\pm}0.9%$ and $78.9{\pm}0.9%$ for training set and $77.7{\pm}10.9%$ and $79.0{\pm}2.8%$ for test set, respectively. Our study demonstrated the feasibility of implementing a piezo snoring sensor based on a portable device as a simple and cost-effective solution for contributing to the OSA screening.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.7
• /
• pp.4450-4458
• /
• 2015

The purpose of this study was to examine the influence of the exercise performance of yoga and pilates on the autonomic nervous system in an effort to provide some clinical information on exercise prescription. The subjects were 20 selected college students who majored in P.E. A yoga group and a pilates group were organized with 10 students respectively, the autonomic nervous system of the students was measured before the exercise, immediately after that and 30 minutes after recovery. The findings of the study were as follows: First, there were significant differences in the yoga group's stress index and average pulse according to the main effect of the time and interaction effect between the time and group. Second, there were significant differences in the yoga group's sympathetic nervous system activity and autonomic nerve balance according to all the main effect of the time, interaction effect between the time and group and the main effect of group. Third, there were significant differences in HRV(Heart Rate Variability), parasympathetic nervous system activity, SDNN, and RMSSD according to the main effect of the time, and interaction effect between the time and group and the main effect of group produced no statistically significant differences. In conclusion, yoga seemed to be effective at lowering stress index and average pulse. Specifically, yoga exercise seemed to exert a more positive influence on the decrease of sympathetic nervous system activity and autonomic nerve balance than pilates exercise.

• Journal of Korean Society of Forest Science
• /
• v.113 no.1
• /
• pp.107-117
• /
• 2024

This study investigated temporal changes in forest physical variables and their effects on thermal comfort and physiological and psychological responses. Environmental factors (air temperature, mean radiant temperature, wind speed, and relative humidity), the predicted mean vote (PMV), and the predicted percentage of dissatisfied (PPD) visitors were continuously measured between 9:00 AM and 6:00 PM. We assessed the physiological and psychological responses (heart rate variability, heart rate, oral temperature, blood pressure, pulse rate, thermal sensation vote, comfort sensation vote, and subjective feelings) of 30 male university students (average age: 21.7±1.9 years), who closed their eyes and relaxed for 5 minutes every hour. Examination of correlations between environmental factors and physiological responses showed that ① the mean radiant temperature, wind speed, and relative humidity significantly changed with time; ② PMV and PPD also showed significant changes over time, and the thermal sensation vote corresponded with PMV; however, the comfort sensation vote did not correspond with PPD; ③ Among the physiological responses, parasympathetic nerve activity, sympathetic nerve activity, heart rate, and diastolic blood pressure significantly varied with time, with parasympathetic nerve activity having the lowest value and sympathetic nerve activity the highest at the highest air temperature (2:00-4:00 PM); and ④ Air temperature, mean radiant temperature, and wind speed showed a negative correlation with parasympathetic nerve activity and a positive correlation with sympathetic nerve activity. These findings indicate that the relaxation effects of the forest environment depend on what time of day people are exposed to it, and the changes occurring in forest environmental factors over time modulate these effects.

• Journal of Korean Society of Forest Science
• /
• v.103 no.4
• /
• pp.664-669
• /
• 2014

This research was conducted to investigate the impact of viewing scenery and walking in the urban forest on physiological relaxation of humans. The experiment was conducted in Hanbat Arboretum located in Daejeon, and the control experiment was conducted in front of Daejeon City Hall. The subjects that participated in the experiment comprised 24 Korean male university students in their 20s (average age, $21.1{\pm}2.5years$), participated in the experiment as the subject, and these subjects were classified into three groups divided into three locations such as the pine forest in Arboretum, the pond in Arboretum, and the city. The subjects sat down and viewed scenery for 10 min, and they then walked for 15 min. Further, physiological changes were measured using indicators such as heart rate variability (HRV), blood pressure, and pulse rate. As a result, when subjects viewed scenery and walked in the urban forest, a statistically significant increase in the high frequency (HF) power of HRV and decrease in systolic pressure was observed compared with when subjects viewed scenery and walked in the city. Through this research, it was found that activities like viewing scenery or walking in Arboretum of the city are effective in increasing the physiological relaxation of the city residents.