• 융합신호처리학회논문지
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• 제1권1호
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• pp.15-22
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• 2000

선형 자귀회귀(AR) 모델을 근거로한 심박변동의 파워 스펙트럼 해석은 비침습적으로 자율신경의 반응을 정량화 하는데 폭넓게 사용된다. 본 연구는 짧은 데이터 저장(2분 미만)의 심전도와 맥파 신호의 심박변동에 대한 파워스펙트럼밀도을 추정한다 심박변동의 시계열은 정상인을 대상으로 검출한 심전도와 맥파신호의 특징점 사이의 시간간격(RRI, PPI)으로부터 구하였다. 발생된 시계열은 다항식 보간법에 의해 AR모델에 적합하게 새로운 시계열로 재구성하였다 AR모델에 의한 파워스펙트럼 밀도는 Burg 알고리즘을 사용하여 계산하였다 AR 모델을 적용한 단 구간의 심전도와 맥파의 심박변동에 대한 파워스펙트럼밀도는 저주파수와 고주파수 영역에서 매끄러운 스펙트럼 파워를 나타내고 있다. 또한 통일한 피험자의 심전도와 맥파의 파워스펙트럼밀도를 비교한 결과 유사한 모양을 나타내었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.165-170
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• 1997

In this paper, we consider the aortic sinus baroreceptor, which is the most representative baroreceptors sensing the variance of pressure in the cardiovascular system(CVS), and propose heart activity control model to observe the effect of delay time in heart period and stroke volume under the regulation of baroreflex in arotic sinus. The proposed heart activity baroreflex regulation model contains CVS electric circuit sub-model, baroreflex regulation sub-model and time delay sub-model. In these models, applied electric circuit sub-model is researched by B.C.Choi and the baroreflex regulation sub-model transforms the input, the arotic pressure of CVS electric circuit sub-model, to outputs, heart period and stroke volume by mathematical nonlinear feedback. We constituted the time delay sub-model to observe sensitivity of heart activity baroreflex regulation model by using the variable value to represent the control signal transmission time from the output of baroreflex regulation model to efferent nerve through central nervous system. The simulation object of this model is to observe variability of the CVS by variable value in time delay sub-model. As simulation results, we observe three patterns of CVS variability by the time delay. First, if the time delay is over 2.5 sec, arotic pressure, stroke volume and heart rate is observed nonperiodically and irregularly. Second, if the time delay is from between 0.1 sec and 0.25 sec, the regular oscillation is observed. Finally, if time delay is under 0.1 sec, then heart rate and arotic pressure-heart rate trajectory is maintained in stable state.

• 대한의용생체공학회:의공학회지
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• 제18권1호
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• pp.37-44
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• 1997

In this paper, the power spectral analysis of heart rate variability(HRV) was performed to evaluate effects of orthostatic stress with head-up tiIt on autonomic nervous system(ANS) for 25 healthy male subjects(age : 24 $\pm$ 5 yr.) and a new method was proposed to assess the autonomic balance. The ECG and respiration signals were recorded at tiIt angles of $0^{\circ}$, $45^{\circ}$, $90^{\circ}$and $0^{\circ}$ successively for 10 minutes per each stage under the condition of frequency controlled respiration(0.25Hz). Heat rate(HR) gradually increased ils the angle increased Similarly, according to the increment of angle, normalized low frequency component(0.05-0.15Hz) gradually increased, whereas normalized high frequency component (0.20-0.30Hz) was reduce4 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 meanthat autonomic nervous system plays a major role in compensating for disturbances of cardiovascular system due to it.

• 대한중풍순환신경학회지
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• 제11권1호
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• pp.1-8
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• 2010

Objectives : We designed this study to investigate difference of heart rate variability(HRV) according to sex, age, acute or chronic phase, category of stroke, national institute of health stroke scale(NIHSS), lesion of stroke. Methods : 64 subjects were recruited from the patients admitted to the department of oriental medicine at East-West Neo Medical Center, Kyung Hee University from 1 September 2009 to 31 August 2010. We compared heart rate(HR), standard deviation of all normal P-P intervals(SDNN), low frequency(LF), high frequency(HF), LF/HF ratio. Results and Conclusions : 1. LF/HF ratio is significantly different between over-70 and below-70 of age. 2. SDNN is significantly different between acute and chronic stroke patients. 3. In sex, category of stroke, national institute of health stroke scale(NIHSS), lesion of stroke, there are no significantly different among the any values of heart rate variability(HRV).

• 대한감각통합치료학회지
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• 제22권1호
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• pp.15-24
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• 2024

목적 : 본 연구의 목적은 내수용 감각(interoception)과 감각처리, 그리고 자율신경계의 균형을 반영하는 심박변이도와의 관계를 알아보는 것이다. 연구방법 : 젊은 성인을 대상으로 청소년/성인 감각프로파일(Adolescent/Adult Sensory Profile; AASP)과 다차원 내수용 자각 척도(Multidimensional Assessment of Interoceptive Awareness; MAIA)를 사용하여 감각처리와 내수용 감각을 평가하였다. 심박은 안정상태 심전도로 기록되었고, 심전도에서 심박표준편차(Standard Deviation of Normal to Normal interval; SDNN)를 추출하였다. AASP 감각영역과 MAIA 하위척도 간 상관을 분석하였고, 높은 SDNN과 낮은 SDNN 집단 간의 감각처리 및 내수용 감각의 차이를 비교하였다. 결과 : AASP 촉각 영역이 MAIA 하위척도와 상대적으로 강한 상관을 나타내었다. AASP 촉각 영역의 점수가 높을수록 MAIA 걱정하지 않음과 주의 조절 점수가 낮은 반면, 정서자각 점수는 높았다. 높은 SDNN 집단은 낮은 SDNN 집단과 비교하였을 때 내수용 감각이 높은 경향성을 나타냈다. 결론 : 본 연구는 촉각 처리와 내수용 감각의 관련성을 확인하였으며, 심박변이도가 높은 그룹은 내수용 자각이 높은 경향성이 있음을 제시하였다. 본 연구는 최근 작업치료와 감각통합에서 강조되는 내수용 감각에 대한 정보를 제공하고, 감각통합의 신경과학적 기전에 대한 이해를 심화시킨다.

• 대한한방부인과학회지
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• 제23권4호
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• pp.155-163
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• 2010

Purpose: The aim of the study was to compare the characteristics of the autonomic innervation of the heart in polycystic ovary syndrome(PCOS) patients with regulary cycling controls. Methods: We studied 21 patients visiting $\bigcirc\bigcirc$hospital from 25th June 2009 to 25th June 2010. The subjects were categorized in two groups, 11 PCOS patients and 10 healthy regularly cycling controls. We studied the difference of Heart rate variability (HRV) between two groups by Independent samples T-test using SPSS for windows(version 17.0). Results: The Standard deviation of all normal R-R intervals (SDNN), The spuare root of the sum of the spuare of difference between adjacent normal R-R intervals (RMS-SD) of PCOS group was non-significantly lower than non-PCOS group. High frequency power (HF) and Normalized high frequency power (HF norm) of PCOS group was significantly higher than non-PCOS group. Normalized low frequency power (LF norm) of PCOS was signficantly lower than non-PCOS group. The results means increased sympathetic and decreased vagal modulation. Total power (TP), Very low frequency power (VLF) of PCOS group was non-significantly lower than non-PCOS group. Low frequency power (LF), LF/HF ratio of PCOS group was non-significantly higher than non-PCOS group. Conclusion: The results suggest that PCOS can be related to decreased activity of parasympathetic nervous system.

• 생물정신의학
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• 제15권3호
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• pp.186-193
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• 2008

Objectives : The authors tried to investigate the characteristics of Heart Rate Variability(HRV) among the subjects with metabolic syndrome for testing the possibility of clinical application of HRV in evaluating metabolic syndrome. Methods : We examined the difference of the means of HRV between 122 subjects of metabolic syndrome and 1057 healthy controls using T-test, and the change of means in HRV according to increasing risk factors of metabolic syndrome. Using multiple regression analysis, we examined the association of HRV with the risk factors of metabolic syndrome. Results : The HRV indices including SDNN(Standard Deviation of all normal NN intervals), RMSSD(the square Root of the Mean Squared Differences of successive all normal NN interval), TP(Total Power), LF(Low Freuency), and HF(High Frequency) were significantly lower in the metabolic syndrome group than in the normal control group, and the means of all HRV indices except LF/HF were decreased consistently according to increasing risk factors of metabolic syndrome. The fasting glucose, triglyceride, and waist circumference were dependent factors that contributed significantly to the change of HRV. Conclusion : These findings suggest metabolic syndrome adversely affects cardiac autonomic system and HRV could be a useful method for evaluating metabolic syndrome.

• 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.

• 한국컴퓨터정보학회논문지
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• 제16권2호
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• pp.17-23
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• 2011

본 연구에서는 일상생활 속에서의 심전도를 측정하여 HRV(Heart Rate Variability)를 모니터링 하며 스트레스를 추정할 수 있는 시스템을 제안한다. 제안된 무선 생체 측정기 모듈은 전처리필터와 BFP사용으로 잡음은 감소 시키면서 신호의 크기는 증가시키기는 회로를 설계하였고, ECG를 측정하여 R-wave를 추출하고 이를 통한 HRV로 인간의 감성 중 스트레스를 평가하는 알고리즘을 개발하였다. 또한 무선 생체 측정기 시스템은 활동 모니터링을 위해 휴대하기 편한 사각형의 작은 사이즈로 구성되며 측정방법이 간단하여 언제든지 측정이 가능하다. 실험을 통해서 취득한 사용자의 HRV 정보는 스트레스 평가 지수 도출 알고리즘을 통한 스트레스를 추정할 수 있으며 스트레스 부하 프로토콜을 수행 한 전후를 비교 분석하여 많은 파라미터에서 유의미한 차이가 나타났다. 본 연구에서 수행된 실험은 일상생활 중에 심장의 전기 활동을 모니터링 할 수 있는무선 생체측정기를 개발하였으며 이를 이용하여 시간영역 분석 및 주파수 영역 분석을 통하여 스트레스 지수를 평가 할 수 있는 알고리즘 시스템은 건강 모니터링 시스템으로 활용도가 높을 것으로 기대된다.

• 디지털콘텐츠학회 논문지
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• 제8권3호
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• pp.355-363
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• 2007

학습자의 성격유형에 따른 학습 선호도는 학습 성취의 주요 인자 중의 하나이다. 따라서 학습자는 자신의 성격 유형과 다른 콘텐츠로 학습을 하게 되면 스트레스가 증가하여 혈압이나 심박동수에 변화가 나타나게 된다. 본 연구에서는 학습자의 비선호도를 측정하기 위해서 스트레스 량 측정에 사용되는 주파수 영역 정보를 이용하였다. 먼저, 13명의 유치원 아동들을 MBTI 성격유형의 감각/직관의 두 유형으로 파악하고 이들에게 동일한 학습 콘텐츠를 10분간 제시한 후, 이를 학습하는 동안 측정된 심전도 신호를 심박변동신호(heart rate variability: HRV) 신호로 재구성하였다. 이 HRV 신호를 주파수로 변환한 후에 저주파(LF: low frequency), 중간 주파(MF: middle frequency), 그리고 고주파(HF: high frequency) 영역으로 분할하고, 각 주파수 영역비를 비교하여 학습자의 성격 유형에 따라 학습 콘텐츠에 대한 선호도가 달라지는 지 여부를 알아보았다. 실험 결과는 아동들은 자신의 성격 유형에 따라 각기 다른 학습 콘텐츠를 선호한다는 사실을 보여준다.