• 전기학회논문지
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• 제65권3호
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• pp.493-498
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• 2016

Heart Rate Variability (HRV) represents beat-to-beat fluctuations of R-R intervals in Electrocardiogram (ECG). On of the clinical applications of HRV is to assess the mental-stress state by evaluating its power spectral density distribution. This study aims at finding new discriminative role of the coupled-oscillating coupling constants, Cs and Cp in the Integral Pulse Frequency Modulation (IPFM) model. Based on comparing with power spectral density of HRV in terms of the relative ratio of the low and high-frequency power component, we can conclude the fact that the coupling parameters Cs and Cp can replace the role of HRV power spectrum interpretation for judging the mental-stress state.

• 대한소아치과학회지
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• 제27권4호
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• pp.494-498
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• 2000

진정요법하의 치과진료에서 환자의 상태를 지속적으로 감시하는 것은 매우 중요하다. 여러 방법 중 가장 널리 사용되는 것 중 Pulse Oximeter가 있다. Pulse Oximeter는 비침습적 방법으로 계속해서 동맥혈액의 산소포화도를 측정할 수 있도록 고안된 장치로서 기기에 나타나는 산소포화도$(SpO_2)$는 실제로 측정한 동맥혈액의 산소포화도$(SaO_2)$와 거의 일치하는 것으로 알려져 있다. 본 진료실에 있는 세종류의 Pulse Oximeter를 이용하여 한 환자에게 동시에 두 개의 기기를 적용하였을 경우, 산출값을 상호 비교한 결과, 짧은(3회) 맥박수를 평균하는 기기가 낮은값이 나왔으며, 다른 두개의 Pulse Oximeter와 유의한 차이가 있는 것으로 밝혀졌다. 짧은 맥박수를 평균하는 기기는 반응이 빠르나, 산소포화도의 값이 작게 산출되고, 외부의 신호에 더욱 민감하여, 오류가 존재할 가능성 또한 높다. 기기의 특성을 알아, 술자는 적절한 기기를 선택하는 것이 중요하다.

• 전기학회논문지
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• 제66권3호
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• pp.581-586
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• 2017

The well-known Integral Pulse Frequency Modulation (IPFM) cardiac oscillator has been used to generate the heart beat fluctuations as a representation of the modulatory autonomic nervous activity in terms of sympathetic and parasympathetic state. The IPFM model produces heartbeats by integrating the modulated sinusoid signals and applying the threshold of unity or chaotic threshold levels. This study aims at evaluating the performance of IPFM model by analyzing the influence of the threshold level with comparatively applying preset threshold of unity and Logistic-map and Henon-map chaotic-threshold. Based on our simulated results with interpreting the spectral features of Heart Rate Variability (HRV), we can conclude that the IPFM model with preset threshold level of unity can generate the optimal heartbeat variations int the sense of clinically valid heartbeats.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.346-355
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• 2017

Atrial fibrillation (AF) and Congestive heart failure (CHF) are increasingly widespread, costly, deadly diseases and are associated with significant morbidity and mortality. In this study, we analyzed three statistical methods for automatic detection of AF and CHF based on the randomness, variability and complexity of the heart beat interval, which is RRI time series. Specifically, we used short RRI time series with 16 beats and employed the normalized root mean square of successive RR differences (RMSSD), the sample entropy and the Shannon entropy. The detection performance was analyzed using four large well documented databases, namely the MIT-BIH Atrial fibrillation (n=23), the MIT-BIH Normal Sinus Rhythm (n=18), the BIDMC Congestive Heart Failure (n=13) and the Congestive Heart Failure RRI databases (n=25). Using thresholds by Receiver Operating Characteristic (ROC) curves, we found that the normalized RMSSD provided the highest accuracy. The overall sensitivity, specificity and accuracy for AF and CHF were 0.8649, 0.9331 and 0.9104, respectively. Regarding CHF detection, the detection rate of CHF (NYHA III-IV) was 0.9113 while CHF (NYHA I-II) was 0.7312, which shows that the detection rate of CHF with higher severity is higher than that of CHF with lower severity. For the clinical 24 hour data (n=42), the overall sensitivity, specificity and accuracy for AF and CHF were 0.8809, 0.9406 and 0.9108, respectively, using normalized RMSSD.

• 전자공학회논문지SC
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• 제46권1호
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• pp.1-9
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• 2009

본 연구에서는 기존의 접촉식 센서를 이용한 생체신호 측정이 아닌 비접촉 방식으로 심박과 호흡을 추출하기 위해 2.4GHz 대역에서 동작하는 도플러 레이더 센서와 베이스 밴드 모듈로 구성된 도플러 레이더 시스템을 설계하고 그 성능을 평가하였다. 설계된 도플러 레이더 시스템은 인체표면의 변위변화에 의해 반사되는 위상변화를 이용하여 심폐 활동을 검출할 수 있다. 도플러 레이더 센서의 I/Q 채널에서 획득한 신호는 베이스 밴드 모듈의 전처리 필터부, 증폭부, 옵셋조정부를 통과하여 호흡과 심박 신호로 분리된다. 도플러 레이더 시스템으로부터 측정된 생체신호와 기존의 생체신호 간의 상관성을 확인하기 위해 호흡과 심박 대역이 각각 다른 쥐, 토끼, 사람을 대상으로 측정하여 그 결과를 비교하였다. 설계된 도플러 레이더 시스템에서 분리된 호흡 및 심박 신호는 측정 대상의 움직임이 없는 상태에서는 높은 검출률을 보였으며, 도플러 레이더에서 심박과 호흡 신호를 검출한 결과 거리, 호흡과 심박의 변이량, 호흡과 심박대역에 따라 검출률이 영향을 받는다는 것을 알 수 있었다.

• Child Health Nursing Research
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• 제6권1호
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• pp.32-50
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• 2000

A descriptive exploratory design was used in this study to evaluate the effects of sponge bathing on physiological(heart rate, heart period, vagal tone, oxygen saturation, respiration) and behavioral responses in newly born 40 preterm infants from intensive care unit of S University Hospital in Seoul. Data has been collected from October, 1997 to March, 1999. The infants were between 27-33 weeks gestational age at birth, and were free of congenital defects. The subjects entered the protocol when they were medically stable (determined by initiation of feeding and discontinuation of all respiratory support) but still receiving neonatal intensive care. The infants' physiologic parameters were recorded a 10 - minute before, during, and after bathing. Continuous heart rate data were recorded on a notebook computer from the infant's EKG monitor. The data were digitized off-line on software(developed by Lee and Chang in Wavelet program) which detected the peak of the R wave for each heart beat and quantified sequential R-R intervals in msec(i.e. heart periods). Heart period data were edited to remove movement artifact. Heart period data were quantified as : 1) mean heart period; 2) vagal tone. Vagal tone was quantitfied with a noninvasive measure developed by Porges(1985) in Mxedit software. To determine behavioral status, tools were developed by Scafidi et al(1990) were used. Collected data were analyzed with the SPSS program using paried t-test, ANOVA, and Pearson correlation. The result were as follow. 1. The results of the ANOVAs indicated that vagal tone were signifcantly lower during bathing than baseline and post-bathing. There were significant differences in heart period and heart rate levels across the bathing. But the mean oxygen saturations and respirations were no differences. Also, there were no significant differences on behavioral sign, motor activity, behavioral distress, weight changes, morbidity, and hospitalization period. 2. To evaluate the relation between vagal tone and subsequent parameters, the two groups (the high group had 19 subjects and low group had 21subjects) were divided by the mean baseline vagal tone. Vagal tone measured prior to bathing were significantly associated with respiration before bathing, vagal tone during bathing, and the magnitude of change in both vagal tone. But, other subsequent reactivities were no differences in two groups. 3. Correlations were also calculated between vagal tone and the subsequent physiological reactivities from baseline through after- bathing. Correlations were significant between baseline vagal tone and baseline heart rate, between baseline vagal tone and baseline heart period, between baseline vagal tone and oxygen saturation after bathing. In summary, the bathing in this study showed a stressful stimulus on premature infants through there was significance in the physiological parameters. In addition, our study represents the documentation that vagal tone reactivity in response to clearly defined external stimulation provides an index of infant's status.

• 대한한방내과학회지
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• 제21권5호
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• pp.747-763
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• 2000

through a literal study upon Arrhythmia between east and west medicine, the results were as follows 1. Arrhythmia is not only irregular cardiac beat but disorder of cardiac impulse making and conduction disturbance. it means almost irregularity of interval between two beat 2. In the east medicine, arrhythmia is represented various category as palpitation, continuous palpitation, dizziness, consumption which give the first consideration by the accompanied symptoms. A separate way in a diagnostics it become a base of diagnosis of diseases and decision of prognosis by the examination of pulse 3. In the west medicine, Arrhythmia is classified as disorder of heart rate, rhythm, conduction disturbance or tachycardia, bradycardia and it is concomitant with fatigue, palpitation, dyspnoea, syncope, chest discomfort 4. The diagnostic study of pulse condition which represent arrhythmia was started from $\mathbb{<}$Nae-Kyung$\mathbb{>}$ and it was revealed as pulse condition of rapid pulse, slow pulse, swift pulse, running pulse, knotted pulse, intermittent pulse etc. Out of them running pulse, knotted pulse, intermittent pulse which obviously are concomitant with irregularity of interval are clinically meaningful in a conditions of disease and decision of prognosis. and the significance of these pulse condition are transformed through the changes of the times 5. According to cause of disease it is classified by Arrhythmia(running pulse, knotted pulse, intermittent pulse) due to heat, cold, phlegm, deficiency(or insufficiency) and There are three categories of etiological factor that is, endogenous, exogenous and non-exo-endogenous factor. the endogenous factor is insufficiency of the heart Ki, deficiency of both Ki and blood, intemal stagnation of phlegm and fluid, stagnation of seven emotions. the exogenous factor is caused by stagnation of Ki and blood by six exogenous pathogenic factor and the non-exo-endgenous factors are improper diet, overstrain, traumatic injury. A cause of arrhythmia in western medicine are a organic and pathological change of the heart itself and malfunction of the autonomic nervous system.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2000년도 추계학술대회 논문집
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• pp.81-87
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• 2000

Beat-to-beat changes in heart period (heart period variability, HPV) are mediated by fluctuations in autonomic activity. Spectral analysis is used to quantify such fluctuations in the range of 0.15-0.40 Hz (high frequency, HF), which are influenced primarily by parasympathetic factors. These fluctuations are often referred to as RSA (respiratory sinus arrhythmia), the physiological phenomenon extracted by spectral analysis and other methods including histograms of heart rate ( HR), deviations of HR etc. Respiratory sinus arrhythmia indexing with peak-to-valley method suggested by Grossman et at., (1981) yields a simple range statistic and is quantified on breath-by-breath basis, thus being quite sensitive and less dependent on recording time as compared to spectral analysis. It is strongly recommended to use at least 1 min epoch to asses HF component of HPV and at least 2 min fer low frequency (LF) of HPV and even 5 min far valid clinical assessment. Peak-to-valley statistic is limited to RSA index only, but has its pragmatic advantages. Most important is possibility of its application far relatively small epoch analysis. We used short periods (20,30, 40 sec only) and off-line analysis of RSA using ECG and respiration curve this method of assessment and proved that this method is more practically effective. The RSA index was not so far dependent on respiration pattern differences and reflected actual vagal control of HR and were accompanied by low HR under some high stress conditions and in an aversive affective visual stimulation experiments. Another factor that might modulate cardiac chronotropic response is the interaction of sympathetic and parasympathetic inputs on sino-atrial (SA) node level, because responses to vagal influences are known to be proportional to ongoing sympathetic activity, that is so called accentuated antagonism. Since sympathetic outflow (increment of influences on SA) under negative emotions or stress was high in almost all physiological responses, vagal effects on HR could be therefore potentiated, leading to masking of output cardiac response seen in HPV, In the case of moderate sympathetic activation, on the other hand, autonomic interactions in cardiac control appear to be minimal. Thus RSA index appears to be an effective alternative method to assess and measure spectral HPV.

• 한국체육학회지인문사회과학편
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• 제57권2호
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• pp.509-518
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• 2018

본 연구는 국민건강 영양조사 자료를 활용하여 한국 성인의 안정시 심박수와 대장암 유병율의 관계를 살펴보고자 하였다. 데이터는 국민건강 영양조사 2005년부터 2014년 자료를 통합하여 만 19세 이상 성인 총 10,564명을 분석하였다. 분석 결과, 안정시 심박수가 가장 높은 그룹은 안정시 심박수가 가장 낮은 그룹에 비해 대장암 유병율이 2.27배 (95%CI: 1.34-3.85) ~ 3배 (95%CI: 1.30-6.92) 더 높은 것으로 나타났으며, 안정시 심박수가 10 회/분 (beat per minutes)씩 증가할수록 대장암 유병율은 1.27배 (95%CI; 1.03-1.58) 증가하는 것으로 나타났다. 또한 65세를 기준으로 연령과 성별을 층화하여 분석한 결과, 65세 이상에서 안정시 심박수가 가장 높은 그룹은 안정시 심박수가 가장 낮은 그룹에 비해 남자는 3.19배 (95%CI: 1.10-9.24) ~ 3.38배 (95%CI: 1.18-9.73), 여자는 2.90배 (95%CI: 1.13-7.42) ~ 5.59배 (95%CI: 1.20-25.99) 대장암 유병율이 증가하는 것을 확인하였다. 본 연구를 통해 대장암 유병율 예측 인자로써 안정시 심박수의 활용 가능성을 확인할 수 있었으며 특히, 65세 이상의 연령이 65세 미만 연령에 비해 안정시 심박수가 대장암 유병율과 밀접한 관련성이 있는 것을 확인하였다.

• Journal of Chest Surgery
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• 제30권9호
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• pp.847-853
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• 1997

Although the effects of adenosine on the heart, including the clinical suppression of cardiac arrhythmias, have been recognized for more than half a century, it is only in the last decade that the therapeutic potential of adenosine has been recognized. The objective of this study was to determine if augmentation of myocardial adenosine levels during global ischemia improves functional recovery after reperfusion. We used to modified Langendonf system to evaluate myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest(15$^{\circ}C$) with modified St. Thomas'Hospital cardioplegic solution used to provide myocardial protection. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegic solution. Two groups of hearts w re studied: (1) control group(n=10) cardioplegia alone; (2) adenosine group(n=10) adenosine(0.75mg/kg/min) added to the cardioplegic solution. Significantly better percent recovery(p<0.01) in hemodynamics(except heart rate) at 60 minutes after reperfusion was evident compared to baseline values in the adenosine group. (systolic no란ic pressure : 78.5$\pm$3.6% vs 66.6$\pm$5.9%, airtic overflow volume : 61.7$\pm$ 11.6% vs 37.2$\pm$ 15.4%, coronary flow volume 77.1$\pm$7.5% vs 57.2$\pm$ 11.1%, and cardiac output : 65.6$\pm$ 11.5% vs 44.2$\pm$ 12.4%). Heart rate was similar in two groups(94.4$\pm$4.8% vs 95.3 $\pm$ 6.8%). Adenosine groups resulted in significantly rapid recovery time of heart beat after reperEusion(p<0.01) (24.5$\pm$7.6 sec. vs 179.0$\pm$ 131.1sec.). In biochemical study, CPK levels(0.1 $\pm$0.3U/L vs 1.4$\pm$0.8U/L) and lactic acid levels(0.08$\pm$0.Immol/L vs 0.34$\pm$0.2 mmol/L) were significantly low in adenosine groups(p<0.01). We concluded that adenosine included cardioplegia have better recovery effects after r perfusion in myocardial ischemia compared to adenosine free cardioplegia.