• Journal of the Korean Society of Radiology
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• v.5 no.1
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• pp.19-25
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• 2011

Photoplethysmogram(PPG) is the method to obtain the biomedical signal using the linear relationships between the blood volume for changing the cardiac contraction and relaxation and the amount of light for absorbing the hemoglobin in the blood. In this paper, we proposed the analyzed results which show the heart rate variability and the distribution of heart rate for before and after using PPG. Moreover, this paper designed and implemented the system based on personal computer to predict cardiovascular disease in advance using the analyzed results for the autonomic balance from taking the spectral analysis of heart rate and the state of the blood vessel for analyzing APG(acceleration plethysmogram).

• The Journal of the Society of Korean Medicine Diagnostics
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• v.10 no.2
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• pp.43-53
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• 2006

Background and Purpose : The Purpose of this study is to review the recent achievements on SDPTG and suggest SDPTG studies. Methods : The study papers related with SDPTC, published in foreign countries and Korea up to the present, were collected by internet search & journal. And then the collected papers were classified and summarized. Results and Conclusion : SDPTG provides informations of arterial elasticity and stiffness. thus, SDPTG could contribute to development of pulse wave diagnosis of oriental medicine.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.11a
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• pp.427-432
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• 1999

지금까지 감성측정은 심박 변화율, 피부저항, 피부온도 등의 생리 신호를 측정하고 그 신호를 이용하여 비교, 분석하여 왔다. 심박 변화율, 피부저항, 피부온도와 마찬가지로 자율신경계 반응의 하나로써 맥파 또한 인간의 감성을 평가하는 한 파라미터가 될 수 있음을 예상하고 본 연구를 수행하였다. 건강한 피험자 5명을 상대로 긍정과 부정 시각 자극을 각각 주어서 심박 변화율과 맥파의 생리신호를 측정한 후 그 동안 발표되었던 심박 변화율의 결과를 기준으로 맥파의 결과와 비교, 분석하였다. 그 결과 평균 R-R 간격의 변화율과 맥파의 최고점 평균 시간 간격의 변화율 그리고 맥파의 최대 기울기점 사이의 시간 간격의 변화율이 유사함을 알 수 있었다. 또한 맥파의 Baseline Deflection 과 Amplitude를 이용하여 감성 측정을 시도하였다. 긍정 시각 자극에 비해 부정 시각 자극 일 때 맥파의 최고점 및 최대 기울기점의 평균 시간 간격은 감소하였고, Baseline Deflection은 증가하였고, Amplitude 는 감소하였다. 이는 부정시각 자극이 교감신경계를 활성화시킴을 보여 주는 것이다. 본 연구를 통하여 맥파도 자율 신경계의 반응을 대면하는 생리신호로써 감성 측정에 유용한 도구임을 검증할 수 있었다.

• Journal of Naturopathy
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• v.7 no.1
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• pp.1-9
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• 2018

The purpose of this study is to statistically investigate the changes in mean differences of the vascular age types and index, heart beating, vessel elasticity, diastolic reserves contents measured by the fingertip plethysmogram before and after the subjects (49 people) visit the Gotjawal forest for two hours. While there is no significant change in the mean differences of vascular age types and index, heart beating, diastolic reserves contents in the control group before and after the visit, the differences in the test groups gets higher than the control group and shows a significant difference. Moreover, the variance analyses of the mean values of the contents shows a significant change after the visit. There is no significant change in the values of vessel elasticity changes between the groups after the visit, but the change of values is significant in the within group, and it is not significant between group by variance analysis. The differences of the heart beating was insignificant in the within group, but significant between group after the visit. In conclusion this study proves the effects of forest bathing, because the HRV index significantly improved after the bathing. Therefore the b-c-d-e/a ratio may be useful for evaluation of HRV.

• Journal of Society of Preventive Korean Medicine
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• v.14 no.2
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• pp.105-120
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• 2010

Objectives : This study aims to evaluate the effects of expiration-to-inspiration time ratio (E/I-ratio) on heart rate, which represents cardiac autonomic function, and cold-heat in the healthy people. Methods : 49 healthy young volunteers(male : female = 32 : 17) were recruited in the study. The participants completed the questionnaire for yin-yang pattern identification and then we measured the chest plethysmogram for respiration signal and the electrocardiogram for NN intervals during different E/I-ratio from 1 to 2. We compared heart rate variability including RMS-SD, VLF, LF and HF, and the trend-cycle factors decomposed from NN interval data by time series analysis among the respective E/I-ratio. We also confirmed the difference on the trend-cycle factors according to the score of the questionnaire for cold and heat pattern identification. Results : There were differences on the trend-cycle factors from NN interval data, but no significant difference on heart rate variability, among the respective E/I-ratio. We also found significant relationship between the trend-cycle factors and the heat pattern identification scores. Conclusions : The results indicate that cardiac autonomic function can be modulated by the E/I-ratio and the modulation will be slower and more tendencious than respiratory sinus arrhythmia.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2265-2267
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• 2007

The purpose of this work is to compare the local fitting and global fitting approaches while applying regression model to the PTT-BP data for the prediction of exercise blood pressures. We used linear and nonlinear regression models to represent the PTT-BP relationship during exercise. PTT-BP data were acquired both under resting state and also after cycling exercise with several load conditions. PTT was calculated as the time between R-peak of ECG and the peak of differential photo-plethysmogram. For the identification of the regression models, we used local fitting which used only the resting state data and global fitting which used the whole region of data including exercise BP. The results showed that the global fitting was superior to the local fitting in terms of the coefficient of determination and the RMS (root mean square) error between the experimental and estimated BP. The nonlinear regression model which used global fitting showed slightly better performance than the linear one (no significant difference). We confirmed that the wide-range of data is required for the regression model to appropriately predict the exercise BP.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.125-126
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• 1998

Pulse conduction velocity is determined by areterial compliance, which is changed by lateral pressure of arterial wall. Hydrostatic pressure of the limb vessel is changed by body position, especially in elevated arm. The arterial pulse in the finger causes the blood volume to change, changing the optical density of the blood. Photoplethysmograph of index finger was obtained by LED and phototransistor. Pulse transmission time(PTT) was measured by the interval between the peak of ECG R wave and the peak of the finger plethysmogram. PTT was increased by upward position of arm, and decreased by downward position of the arm compared to horizontal position. This result suggests that relationship between finger plethysmography and postural change could be applied to evaluate clinical cardiovascular status.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.10 no.2
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• pp.54-66
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• 2006

Objective : To review the method, parameters, system of electrogastrography and to study its oriental medical application. Method : We investigate the research results through internet search engines such as Pubmed, China National Knowledge Infrastructure. Conclusion : Electrogastrography is believed to be of great use to the verification of treatment effect of herbal medicine that is used in internal medicine and neuropsychiatry, along with the objectification and quantification of diagnosis of oriental medicine related to gastric peristalsis and balance of autonomic nervous system. I would therefore like to conclude that there should be continued study and active application of electrogastrography in the wide variety of oriental medicine.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1780-1787
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• 2014

Arterial oxygen saturation ($SpO_2$) monitoring for newborns requires special attention in neonatal intensive care units (NICUs). Newborns have very low photo-plethysmogram (PPG) amplitudes and their body movements are difficult to contain. Hardware design and its associated signal processing algorithms should be robust enough so that faulty measurements can be avoided. In this study, improved designs were implemented to deal with low perfusion, motion artifact, and the influence of ambient light. Dynamic range was increased by using different LED intensities and a feedback system. To minimize the effects of motion artifact and to discard other unqualified data, four additional algorithms were used, which were based on dual-trace detection, continuity of DC level, morphology of PPG, and simultaneity check of $SpO_2$. Our $SpO_2$ system was tested with newborns with normal respiration in the NICU. Our system provided fast, real-time responses and 100% artifact detection was accomplished under 84% of $SpO_2$.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.120-124
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• 1988

Phenol sympathetic block is valuable for the treatment of ischemic pain, gangrene, intermittent claudication, Paget's disease of the bone and pain associated with pancreatitis, pancreatic carcinoma, etc. The author has experienced a case of successful lumber sympathetic block using 7% phenol under fluoroscopy and given to a patient with Buerger's disease who had severe pain and ulceration of the right great toe for several years. After the sympathetic block, 2 epidural blocks with 2.5% bupivacaine were done in order to augment the effects of this sympathetic block. Subsidence of rest pain, increase in walking distance from under 100 M to over 500 M and circulatory improvement of the affected limb were observed, Improvement of circulation was confirmed by strain gauge plethysmography.