• 한국전기전자재료학회논문지
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• 제21권8호
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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.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 추계학술대회 논문집
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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.

• 대한한의학회지
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• 제35권4호
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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.

• 대한의용생체공학회:의공학회지
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• 제42권3호
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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.

• 대한의용생체공학회:의공학회지
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• 제25권6호
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• pp.623-628
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• 2004

본 논문에서는 원적외선 온열효과가 자율 신경계에 미치는 영향을 심박변동(HRV)을 이용하여 평가 하였다. 측정된 심박변동신호를 FFT 의한 전력스펙트럼을 구함으로써 자율 신경계의 반응 특성을 고찰하고 Poincare plot 분석 방법을 이용하여 결과를 비교 분석하였다. 실험을 통해 심박변동 신호분석해보면 원적외선 온열에 노출되기 전에 비해 노출된 후에 매우 복잡한 모습임을 관찰 할 수 있었는데 이것은 자율신경계가 관여하는 심혈관계 제어 메커니즘이 원적외선 온열에 노출되기 전보다 노출된 후에 더욱 복잡함을 반영하는 것으로 분석된다.

• 감성과학
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• 제14권4호
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• pp.503-512
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• 2011

최근 HCI 분야에서 정서 인식은 정서 지능을 구현하기 위한 핵심적인 단계 중의 하나이다. 생체신호를 이용하여 정서 인식을 시도하는 연구들이 시도되고 있으나, 기본 정서 이외의 다른 정서에 대한 연구는 거의 이루어지지 않았다. 본 연구의 목적은 무료함, 통증, 그리고 놀람의 세 가지 정서 간 자율신경계 반응의 차이를 확인하는 것이다. 실험자는 217명의 실험참여자(남 96명)들을 대상으로 시/청각 자극을 조합하여 무료함과 놀람 정서를 유발하였고, 혈압기를 이용하여 통증 정서를 유발하였다. 정서 자극이 제시되는 동안 피부전기활동, 피부온도, 심전도와 광혈량도를 측정하였고, 실험참여자들이 경험한 정서 범주와 강도를 정서평가척도 상에 평정하게 하였다. 정서 자극에 대한 평가 결과, 사용된 정서 자극은 평균 92.5%의 적합성과 5.43의 효과성을 보였는데, 이는 각 정서 자극이 해당 정서를 효과적으로 유발한 것을 의미한다. 자율신경계 측정 결과, 피부전기활동, 피부온도, 심박률, 심박률의 저주파수 성분과 평균 혈류량은 안정 상태와 정서 상태 간의 유의한 차이를 보였다. 또한 각 정서에 의해 유발된 자율신경계 반응은 정서 간에도 유의한 차이가 있는 것으로 나타났다. 이러한 결과는 정서이론의 확장과 자율신경계 반응 측정 지표를 활용하여 정서를 인식하는 알고리즘 및 인간 정서를 변별하는 컴퓨터 시스템 개발에 응용 가능할 것이다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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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.

• 동의신경정신과학회지
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• 제25권3호
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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.

• 감성과학
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• 제4권2호
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• pp.39-45
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• 2001

본 연구는 향에 대한 연령별 감성구조를 밝히고, 향 감성에 따른 자율신경계 반응을 규명하기 위해 수행되었다. 실험 참여자는 연령별(10대, 20대, 40대)로 24명씩 총 72명이고, 자극향은 cederwood, grapefruit, teebaum, peppermint, rose향을 사용하였다. 향이 제시되는 동안 혈류량, 피부온도, 피부전기 반응, 심전도 반응을 측정하였고, 향에 대한 주관적 감성을 측정하였다. 향에 의한 심리적 감성구조는 심미성, 강도, 자연성, 개성성, 낭만성의 다섯 요인이 확인되었고, 연령별로 차이가 나타나지 않았다. 향 선호도를 예측하는 감성요인은 연령별에 따라 부분적으로 차이가 있었다. 감성적으로 “나쁜” 향은 “좋은” 향보다 교감신경계 활동에 의한 자율신경계 반응이 더 크게 일어났다.

• 전기학회논문지
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• 제57권6호
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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.