• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.770-775
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• 2008

Autonomic nervous system of the anesthetized patients can be influenced by the many kinds of stimulations such as intubation, surgical incision and so on. The changes of the heart rates and blood pressures are surrogates of responses of the autonomic system to the external stimulations. Recently, the power spectral analysis of the heart rate variability (HRV) made it easy to know the fractions and changes of sympathetic and parasympathetic autonomic systems. In this study, the changes of pulse transit time, one of the response of vessels to stimulations, was investigated in relation to the HRV. Ten patients were examined and average age is 22.5 $\pm$ 11.04, average weight is 63 $\pm$ 14.4 kg. The patients were anesthetized only by sevoflurane inhalation. Pulse transit time is determined by calculating the difference of the time between the R peak of ECG and the characteristic point of the plethysmography. Power spectral density (PSD) of the HRV was achieved in the frequency of 0.04-0.15 (LF) and 0.15-0.4 (HF). Compared to preanesthetic period the values of LF and LF/HF ratio of HRV were decreased (p<0.05). HF and PTT was increased in anesthetic state with sevoflurane. Otherwise, after intubation, the HF was decreased and LF, LF/HF ratio and PTT were increased. PSD of the HRV is well-known for the index of the autonomic nervous activity. Not only HRV but PTT analysis also is a useful index reflecting the autonomic responses to various stimulations. And this analysis is useful in bed side monitoring because the calculating method is simple and it takes shorter processing time compared to the HRV analysis.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.11a
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• pp.216-221
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• 1999

A mental task combined with noise background is an effective model of laboratory stress for study of psychophysiology of the autonomic nervous system (ANS). The intensity of the background noise significantly affects both a subjective evaluation of experienced stress level during test and the physiological responses associated with mental load in noisy environments. Providing tests of similar difficulties we manipulated the background noise intensity as a main factor influencing a psychophysiological outcome and the analyzed reactivity along withe the noise intensity dimension. The goal of this study was to identify the patterns of ANS responses and the relevant subjective stress scores during performance of word recognition tasks on the background of white noise (WN) of the different intensities (55, 70 and 85 dB). Subjects were 27 college students (19-24 years old). BIOPAC, Grass Neurodata System and AcqKnowlwdge 3.5 software were used to record ECG, PPG, SCL, skin temperature, and respiration. Experimental manipulations were effective in producing subjective and physiological responses usually associated with stress. The results suggested that the following potential autonomic mechanisms might be involved in the mediation of the observed physiological responses: A sympathetic activation with parasympathetic withdrawal during mild 55 and 70dB noise (featured by similar profiles) and simultaneous activation of sympathetic and parasympathetic systems during intense 85dB WN. The parasympathetic activation in this case might be a compensatory effect directed to prevent sympathetic domination and to maintain optimal arousal state for the successful performance on mental stress task. It should be mentioned that obtained results partially support Gellhorn's (1960; 1970) "tuning phenomenon" as a possible mechanism underlying stress response.

• The Journal of Korean Medicine
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• v.35 no.4
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• pp.24-35
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• 2014

Objectives: Although the autonomic nervous system (ANS) is thought to play an important role in treatment of obesity, no study has been conducted to investigate acupuncture's effects on this aspect of the ANS. This study aimed to describe the effects of acupuncture in the ANS by means of heart rate variability (HRV) analysis. Methods: A total of 46 obese women aged from 21 to 54 with body mass index ranging from 25.1 to $39.3kg/m^2$ were recruited and randomized into both the real acupuncture group (n=23) and sham acupuncture group (n=23). A total of 3 instances of HRV analysis were conducted before, during, and after treatment. Statistically significant differences between time and groups were analyzed using repeated measure analysis of variance. Results: All parameters of time domain analysis and frequency domain analysis except for the square root of the mean squared differences of successive normal sinus intervals (RMSSD) and very low frequency (VLF) showed significant differences between times. The mean of all R-R intervals (mean RR) showed significant level of interaction between time and group. Between groups, time domain analysis of standard deviation of the normal-to-normal intervals (SDNN), RMSSD and frequency domain analysis of total power (TP) and high frequency (HF) showed significant differences. Conclusions: The real acupuncture group showed deactivation of parasympathetic function and relative increase of sympathetic activity in obese subjects. Further studies are necessary to uncover the mechanisms of acupuncture in obesity treatment.

• Journal of Biomedical Engineering Research
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• v.42 no.3
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• pp.107-115
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• 2021

Purpose: The aim of this study is to find the location of acupoints that are effective for increasing parasympathetic nervous system(PNS) activity among acupoints used to relieve symptoms such as dizziness and nausea. Materials and Methods: Twenty healthy adult men participated in this experiment. Transcutaneous electrical nerve stimulation(TENS) was applied to P6(Neiguan), ST36(Zusanli) and BL20(Pishu) for 30 minutes. For 5 minutes before and after stimulation, Electrocardiogram(ECG), Electrodermal activity(EDA), Respiration, and Skin temperature(SKT) were measured using biosignalsplux Professional(biosignalsplux; Portugal). Paired t-test was performed for the results before and after stimulation, and a one-way ANOVA test between stimulations was performed for the rate of change before and after stimulation. Results: When each acupoint was stimulated with TENS, it was found that the PNS was generally activated. In addition, when considering the change in biosignals after stimulation, the participants stimulated with P6 showed the most consistent results. Conclusion: As a result of stimulating each acupoint, it was found that stimulating P6 can effectively increase PNS activity. These results indicate that methods of stimulating P6 may be most effective in alleviating symptoms of motion sickness.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.623-628
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• 2004

This paper describes autonomic nervous system activities caused by hyperthermia of far-infrared ray on human body. Designed protocol and analysis algorithm were evaluated by experiments on 20 subjects to analyze the characteristic of heart rate variability(HRV) signals which could be analyzed by FFT power spectrum and time-frequency analysis. Using Poincare' plot analysis, LF and HF were compared with SD1 and SD2. During the experiment, subject was exposed to hyperthermic effects of far-infrared radiation. We could confirm that far-infrared ray, which was known to improve the blood circulation, stress state and enhancing thermal effect into human body, had an effect on human nervous system. As the hyperthermic temperature of far-infrared ray increased, the activity of cardiovascular system to sustain the homeostasis was observed by means of investigating the increase of the sympathetic activity.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.503-512
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• 2011

Recently in HCI research, emotion recognition is one of the core processes to implement emotional intelligence. There are many studies using bio signals in order to recognize human emotions, but it has been done merely for the basic emotions and very few exists for the other emotions. The purpose of present study is to confirm the difference of autonomic nervous system (ANS) response in three emotions (boredom, pain, and surprise). There were totally 217 of participants (male 96, female 121), we presented audio-visual stimulus to induce boredom and surprise, and pressure by using the sphygmomanometer for pain. During presented emotional stimuli, we measured electrodermal activity (EDA), skin temperature (SKT), electrocardiac activity (ECG) and photoplethysmography (PPG), besides; we required them to classify their present emotion and its intensity according to the emotion assessment scale. As the results of emotional stimulus evaluation, emotional stimulus which we used was shown to mean 92.5% of relevance and 5.43 of efficiency; this inferred that each emotional stimulus caused its own emotion quite effectively. When we analyzed the results of the ANS response which had been measured, we ascertained the significant difference between the baseline and emotional state on skin conductance response, SKT, heart rate, low frequency and blood volume pulse amplitude. In addition, the ANS response caused by each emotion had significant differences among the emotions. These results can probably be able to use to extend the emotion theory and develop the algorithm in recognition of three kinds of emotions (boredom, surprise, and pain) by response measurement indicators and be used to make applications for differentiating various human emotions in computer system.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.443-446
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• 1997

HRV(heart rate variability) is the time series data of R-R interval time duration based on ECGs. Power spectral analysis of HRV has recently been used to define the activity of ANS(autonomic nervous system). In this study, 14 rats were divided into two groups, sympathectomy and vagotomy. During the experiments, ECGs of rats were collected three times at each experimental conditions or the duration of 5 minutes, where sampling frequency was set at 2KHz. After the application of the Berger's Serires algorithm to ECG raw data, power spectrum of HRV was obtained via FFT. Results showed that HF/LF were increased or the sympathectomy group and decreased or the vagotomy group. It implies that the variations in HF/LF components could be used or the ANS function classification.

• Journal of Oriental Neuropsychiatry
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• v.25 no.3
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• pp.235-242
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• 2014

Objectives: The purpose of this research is to examine effects of acupuncture treatment on the autonomic nervous systems of Hwa-byung patients with insomnia. Methods: The study was performed through a patient-assessor blind, randomized, placebo-controlled trial in which the volunteers, data collectors, and analysts were unaware of which individuals were receiving the treatment. A total of thirty-seven volunteers were divided into 2 groups. Eighteen subjects were placed into a trial group and 19 subjects into a control group using a randomization table. The trial group was treated with bilateral Shigu, Ahnmyun, B62 (Shinmaek), and K6 (Chohae), while the control group was not given any other treatment. The ISI (Insomnia Severity Scale) was measured as the first evaluative instrument, and then a comparative analysis was conducted by comparing the results with those measured by ANS (BVP/HR, respiration rate, peripheral temperature, skin conductance, EMG). Results: In the BVP/HR, statistically significant decreases were found in those from the trial group compared to those of the control group. Skin conductance was found to be significantly increased in the trial group, as compared to the control group. However, there were no significant differences between the groups with respect to peripheral temperature, respiration rate, and EMG. Conclusions: The results suggest that acupuncture treatment is effective in the treatment of hwa-byung patients who suffer from insomnia due to their autonomic nervous systems.

• Science of Emotion and Sensibility
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• v.4 no.2
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• pp.39-45
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• 2001

This study was conducted to identify the structure of the sensibility and autonomic nervous responses to odor by ages. 72 participants, 24 each in their teens, twenties, and thirties were given odor stimuli, cederwood, grapefruit, teebaum, peppermint, rose. During the presentation of stimuli, participant were measured blood flow, skin temperature, skin conductance, and ECG and subjective emotion to each odor were evaluated, Five factors, aesthetic, intensity, naturality, uniqueness, and romantism were identified but there were no differences by ages. Emotional factors that predict the preference to certain odors turned out partly different by ages. However, odors that made participants feel sick created more autonomic nervous response than odors that made them feel good.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.1087-1094
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• 2008

This study describes a system for human sensibility evaluation using PPG(photoplethysmogram) signal and biofeedback algorithm to respond the bad(negative) mood. For this objective, PPG signals for two emotional states(positive/negative) are collected. To evoke the test emotions, happy(or joyful) and sad(or irritating) movie files are collected and played in subjects' monitor. From the acquired PPG signal, the heart rate variability(HRV) is calculated. Using the HRV and its FFT spectra, the human sensibility is evaluated. Since the heart is a representative organ which is controlled by the autonomic nervous system(ANS), the ANS may reflect the changes in emotion. The biofeedback algorithm is designed with motion image player interacting with the results of the sensibility evaluation. It was shown that HRV was changed according to the subject's emotions. Accordingly, the sensibility evaluation test showed feasibility of the our method.