• Science of Emotion and Sensibility
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• v.8 no.1
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• pp.29-36
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• 2005

This study investigated which recumbent posture can give rise to the highest vagal modulation in patients with coronary artery disease(CAD), among three recumbent postures; namely, the supine, left lateral, and right lateral postures. For this purpose, 43 patients as CAD group and 31 patients as control group were studied. Heart rate variability(HRV) was measured on these patients for three recumbent postures in random order Normalized high-frequency power was the highest, whereas normalized low-frequency power was the lowest in the right lateral postures, among the three recumbent postures.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.151-158
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• 2003

Numerous studies of short-term, beat-to-beat variability in cardiovascular signals have used linear analysis techniques. However, no study has been done about the appropriateness of linear techniques or the comparison between linearities and nonlinearities in short-term, beat-to-beat variability. This paper aims to verify the appropriateness of linear techniques by investigating nonlinearities in short-term, beat-to-beat variability. We compared linear autoregressive moving average(ARMA) with nonlinear neural network(NN) models for predicting current instantaneous heart rate(HR) and mean arterial blood pressure(BP) from past HRs and BPs. To evaluate these models. we used HR and BP time series from the MIMIC database. Experimental results indicate that NN-based nonlinearities do not play a significant role and suggest that 10 technique provides adequate characterization of the system dynamics responsible for generating short-term, beat-to-beat variability.

• The KIPS Transactions:PartD
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• v.16D no.1
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• pp.11-26
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• 2009

In order to diagnose cardiovascular disease, we proposed EP-based(emerging pattern- based) classification technique using multi-parametric diagnosis indexes. We analyzed linear/nonlinear features of HRV for three recumbent postures and extracted four diagnosis indexes from ST-segments to apply the multi-parametric diagnosis indexes. In this paper, classification model using essential emerging patterns for diagnosing disease was applied. This classification technique discovers disease patterns of patient group and these emerging patterns are frequent in patients with cardiovascular disease but are not frequent in the normal group. To evaluate proposed classification algorithm, 120 patients with AP (angina pectrois), 13 patients with ACS(acute coronary syndrome) and 128 normal people data were used. As a result of classification, when multi-parametric indexes were used, the percent accuracy in classifying three groups was turned out to be about 88.3%.

• Journal of Korean Biological Nursing Science
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• v.11 no.1
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• pp.32-41
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• 2009

Purpose: This study was to identify the effects of aroma inhalation therapy on heart rate variability and anxiety in the context of urodynamics study. Method: The data were collected from 64 patients who were receiving urodynamics at the C University Medical Center in Seoul, 23 in the experimental group, 22 in the placebo group and 19 in the control group. In the experiment, the subjects of the experimental group inhaled a mixture of lavender and bergamot for 5 min, the subjects of the placebo group inhaled geranyl acetate oil for 5 min and the subjects of the control group relaxed for 5 min. The instruments used in this study included the state anxiety inventory and heart rate variability. Result: The score of state anxiety was no significant differences between the three groups after aroma-inhalation. Also, the sympathetic nerve activity and parasympathetic nerve activity was no significant differences between the three groups after aroma-inhalation. Autonomic nerve balance was maintained significantly in the experimental group as compared to the control groups after aroma-inhalation. Conclusion: The aroma inhalation therapy was very effective in balancing the autonomic nervous system in the patients undergoing urodynamic study.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.569-572
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• 2010

A 4-year-old neutered female Pekingese dog (weighing 3.6 kg) was referred with the primary complaint of exercise intolerance with occasional syncope. Physical examination revealed irregularly irregular heart rhythm with persistent pulse deficits. The 12-lead surface ECG showed a marked sinus arrest with occasional junctional escape beats, indicating a sick sinus syndrome. Permanent transvenous cardiac pacing with a rate-responsive bipolar implantable pacemaker (VVIR type) was performed in the right ventricle. After pacemaker implantation, the clinical signs were remarkably improved. No further syncopal episodes have yet been occurred after implantation.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1822-1825
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• 2015

본 논문에서는 운동 전후 또는 심장 질환과 관련 있는 사용자가 체중을 측정하면서 동시에 심전도 신호를 측정하여 운동 부하에 따른 심장의 활동 상태를 모니터링 할 수 있는 장치를 고안하였다. 이를 위한 방법으로 체중계에 수정된 바이폴라 금속전극을 적용하여 표준사지 측정법을 이용하여 심장활동 신호를 측정할 수 있는 방법을 제안하였다. 체중계에서 심전도를 측정하기 위해 기존의 Ag-AgCl 전극이 아닌 금속 판 형태의 전극을 사용하였으며 이를 위해 입력 임피던스의 설계를 브릿지 형의 AC-Coupling 회로를 통해 높은 CMRR이 유지되도록 설계하였다. 또한 시시각각 변화하는 노이즈를 제거하기 위해 Savitzky-golay filter를 사용하였으며 이를 통해 Baseline wandering 이 제거된 최종 심장활동 신호를 획득하였다. R-peak 검출을 통해 기준신호와의 심박수 및 Sensitivity의 비교평가를 수행하여 이 장치의 성능을 평가한 결과 심박 검출률의 평균 Sensitivity가 97.1%로 나타났다. 동잡음 제거에 대한 알고리즘이 보다 최적화 되어 최종 출력 신호의 안정성이 향상 된다면 체중계를 통한 심박 검출의 가능성과 그 유효성이 충분할 것으로 사료된다.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.5
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• pp.486-494
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• 2014

Intelligent homes consist of ubiquitous sensors, home networks, and a context-aware computing system. These homes are expected to offer many services such as intelligent air-conditioning, lighting control, health monitoring, and home security. In order to realize these services, many researchers have worked on various research topics including smart sensors with low power consumption, home network protocols, resident and location detection, context-awareness, and scenario and service control. This paper presents the real-time metabolic rate estimation method that is based on measured heart rate for human adaptive appliance (air-conditioner, lighting etc.). This estimation results can provide valuable information to control smart appliances so that they can adjust themselves according to the status of residents. The heart rate based method has been experimentally compared with the location-based method on a test bed.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.646-654
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• 2011

Recently, the task in which the number of people of the emergency medical technician whom it boards the ambulance is unreasonably insufficient and in which the fire fighter one person gets in the ambulance and which transfers the patient comes into question often. When the emergency patient is generated, it has to transfer to the special hospital in which above anything else, the measure which is quick and exact is needed and where there is the medical device which is suitable for particularly, the patient. This paper implementations the emergency medical system by the smart phone. The implemented system monitors the heart beat of the patient the monitoring among the patient transport with the real-time type. It can grasp the medical history information of the patient, and etc. in the past. And the system provides the emergency hospital which the patient requires and the pre-hospital phase provides the environment in which the disposition which is quick and efficient is possible to the emergency patient.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.242-248
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• 2000

본 연구에서는 가상현실에서 simulator factor [FOV (field of view)와 운행속도, frame rate의 fluctuation]를 변화시키면서 사용자들의 시지각 과제수행도, 생리신호의 변화를 관찰하였고, 가상현실 경험 전·후에 실시한 설문지 조사를 통해 심리적 영향도 알아보았다. 1) 가상현실 운행시 눈깜박임이감소하고 Pz, O1, O2 영역의 알파파가 줄어들며 텔타파가 늘어나는 생리적 변화가 나타났다. 2) 특히 가상현실에서 멀미를 보고했을때 심박률, 피부전도도가 증가하고 피부온도가 감소하는 것으로 나타났다. 멀미 보고시 나타난 변화는 교감신경계의 활동성이 증가하는 방향과 일치하였다. 3) 빠른 운행속도가 느린 운행속도보다 높은 말초혈류량 최대-최소차이값을 나타냈고, 넓은 FOV가 좁은 FOV보다 높은 심박률을 나타냈다. 좁은 화면 보다 넓은 화면 조건에서 Cz, Pz 영역의 알파파는 더 낮게 나타났고 텔타파는 더 높게 나타났다. frame rate의 fluctuation이 없을 때에 비해 있을때 더 높은 피부전도도를 보여주었다. 4) 가상현실 평가설문지 분석결과 신체적 불편감은 좁은 FOV·느린 운행속도 조건에서 가장 적은 불편감을 나타냈다. 과제수행 곤란도는 느린 운행속도에서 가장 적게 나타났고 과제수행 적중률은 느린 운행속도에서 가장 높게 나타났다. 생리신호, 과제수행 적중률, 설문지 분석결과는 좁은 FOV·느린 운행속도의 가상환경이 가장 멀미에 덜 민감하고 과제수행하기에 가장 용이한 것으로 나타났다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.253-254
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• 2017

본 논문에서는 타인의 도움 없이 자율적으로 환자를 따라다니며 환자의 상태를 주기적으로 주치의에게 전달하는 스마트 링거대를 구현하였다. 기존의 링거대는 환자 혼자 끌고다니며 움직이기에는 여러 가지 불편한 점이 있다. 예를 들면 잠을 잘 때 링거대의 위치를 환자가 직접 옮겨놓고 자야하며, 옮기기도 몸이 불편한 환자 입장에서는 많은 어려움이 따른다. 또 링거액을 다 썼을 때도 간호사에게 직접 가서 말을 해야 하거나, 피가 역류했을 때도 불편한 몸을 이끌고 간호사에게 가야 한다. 이런 여러 가지 불편함을 스마트 링거대를 제작함으로써 링거대의 이동부터 여러 가지 도움이 필요한 상황이 발생 시 간호사에게 연락을 할 수 있도록 하며, 여러 가지 돌발 상황을 대비하여 추가적으로 심박동 및 체온을 측정하여 이상이 발생 할 시 자동적으로 간호사와 보호자에게 연락이 갈 수 있도록 함으로써 병원에서 환자에게도, 간호사에게도 큰 도움이 될 것이라고 사료된다.