• 전자공학회논문지
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• 제52권8호
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• pp.18-26
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• 2015

올바른 운동량 조절을 위해선 운동중의 심박수 측정이 중요하다. 최근 스마트 디바이스가 활발하게 사용됨에 따라, 운동중의 실시간 심박수 측정에 대한 관심이 급격하게 증가하고 있다. 고강도 운동 중에는 동잡음으로 인하여 손목 밴드 유형의 광혈류 (PPG : photoplethysmography) 측정기 신호로부터 정확한 심박수를 추정하는 것이 매우 어렵다. 본 논문에서는 손목밴드 유형의 광혈류 측정기 신호로부터 정확한 심박수 추정을 위한 효율적인 알고리즘을 제안하였다. 12개의 데이터 세트에 대하여 제안하는 알고리즘을 적용한 결과, 1.38의 분당심박수(BPM) 평균 절대 오차를 기록하였고, 0.9922의 추정 심박수와 실제 심박수간의 Pearson 상관계수를 얻었다. 제안하는 알고리즘은 웨어러블 디바이스에 적합한 빠른 연산속도와 정확한 추정을 가능케 한다.

• 수산해양기술연구
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• 제39권2호
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• pp.128-133
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• 2003

본 연구에서는 스트로보광의 자극효과를 검토할 목적으로 스트로보광 강도에 따른 전갱이의 반응을 심박수의 변화로 조사하였다. 실험은 10$Hz$의 스트로보광강도(75 lx$\cdot$s)를 1/2, 1/5, 1/15로 빛의 세기를 감소시켜, 4단계의 강도별로 심박수를 자극 전 10분간, 자극 중 30분간, 자극 후 20분간 합계 60분간을 2시간마다 3회 연속해서 측정하였다. 그 결과, 스트로보광자극 중의 심박수 증가와 자극 종료직후에 일시적으로 현저한 심박수 감소가 있었다. 스트로보광 자극효과는 자극강도의 감광에 따라 감소하였다. 반복실험에 의한 자극효과는 75 lx$\cdot$s의 강도보다 약한 스크로보광 강도에서는 현저하게 나타나지 않았다.

• 동의신경정신과학회지
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• 제20권4호
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• pp.127-135
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• 2009

Objectives : This study was conducted to assess the effect of Chunwangbosim-dan(CB) on the autonomic nervous system by using heart rate variability measurement. Methods : The eligible subjects were composed of the healthy female group of ages 25 to 30 years. They were divided into two groups, the CB group(n=16) and the control group(n=16). We measured the heart rate variability respectively for 3 times at 14:00, 16:00, and 17:00. In the CB group, subjects were administered CB at 15:00. For the measurement values, Mean Heart Rate and SDNN(standard deviation of the NN intervals) were used as time domain analysis, and HF(high frequency), LF(low frequency), and LF / HF ratio were used as frequency domain analysis. Results : The degree of LF changes in the CB group was significantly lower than control group at 1 hour after administration. Conclusions : We suggest that Chunwangbosim-dan may be useful for stabilization of the autonomic nervous system by controlling sympathetic nerve in healthy people.

• Journal of Korean Biological Nursing Science
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• 제17권3호
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• pp.271-276
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• 2015

Purpose: This study was to evaluate the effects on the heart rate and respiration rate of preterm infants when providing auditory stimulation on them. Methods: The design of this study was a nonequivalent control group pretest-posttest design in a quasi experimental study. Forty preterm infants were assigned to experimental and control groups : 20 in the auditory and 20 in the control group. The data were collected from May 2014 to October. The auditory stimulation was created by using an audio music tape provided 20-minute per day for 7 consecutive days. In data analysis, SPSS WIN 21.0 program was utilized for descriptive statistics, repeated measurement anova and Mann-Whitney. Results: General characteristics of the two groups showed no significant differences, thus two groups were found to be homogenous. There were no significant differences in heart rate and respiration rate between the auditory and control groups. Conclusion: The effect of auditory stimulation for 7 days was not effective in decreasing heart rate or respiration rate in premature infants. Therefore, the type and length of music therapy must be developed for the improvement of vital signs in preterm infants who were hospitalized in a neonatal intensive care unit.

• 감성과학
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• 제4권1호
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• pp.1-5
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• 2001

The evaluation of mental workload is measured by subjective ratings, physiological signals. It takes long time to analysis the measured signals and is very tedious and time-consumming work. Therefore, to evaluate the affect of workload effectively, real-time measurement system is required. In this paper, real-time mental workload measurement system using cardiac autonomic indiced which reflect well the mental workload was developed and evaluated. Analyzed indices were HR, IBI, Lorentz plot, CSI, CVI, and LF/HF ratio of heart rate variability. The system was applied to evaluate the affect of arithmetic task and showed good results. This system was consisted of ECG amplifier, A/D converter, and personal computer, and algorithm was implemented using LabVIEW.

• 대한의용생체공학회:의공학회지
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• 제39권2호
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• pp.87-93
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• 2018

The measurement of Heart Rate Variability (HRV) using electrocardiogram (ECG) signals has been used to predict fatigue and stress levels in a clinical environment, yet, owing to the complexity of such ECG systems, a domestic, nonclinical monitoring of HRV has not been a practical possibility. Recently though, Pulse Rate Variability (PRV) has been studied as an alternative to HRV. In this study, we investigated the reliability of measuring PRV by means of a smartwatch. The PRV results were compared to HRV results in similar test conditions, i.e. those obtained under rapid and deep-breathing scenarios. From the results obtained, it transpires that the Bland-Altman ratio and cross-correlation coefficients between several PRV and HRV parameters were highly correlated, thus suggesting that the results of measuring PRV using a smartwatch can be used to predict HRV in nonclinical environments.

• 대한임베디드공학회논문지
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• 제18권6호
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• pp.277-283
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• 2023

Vital signals provide essential information regarding the health status of individuals, thereby contributing to health management and medical research. Present monitoring methods, such as ECGs (Electrocardiograms) and smartwatches, demand proximity and fixed postures, which limit their applicability. To address this, Non-contact vital signal measurement methods, such as CW (Continuous-Wave) radar, have emerged as a solution. However, unwanted signal components and a stepwise processing approach lead to errors and limitations in heart rate detection. To overcome these issues, this study introduces an integrated neural network approach that combines noise removal, demodulation, and dominant-frequency detection into a unified process. The neural network employed for signal processing in this research adopts a MLP (Multi-Layer Perceptron) architecture, which analyzes the in-phase and quadrature signals collected within a specified time window, using two distinct input layers. The training of the neural network utilizes CW radar signals and reference heart rates obtained from the ECG. In the experimental evaluation, networks trained on different datasets were compared, and their performance was assessed based on loss and frequency accuracy. The proposed methodology exhibits substantial potential for achieving precise vital signals through non-contact measurements, effectively mitigating the limitations of existing methodologies.

• 융합신호처리학회논문지
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• 제19권1호
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• pp.14-19
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• 2018

최근 건강에 대한 관심과 욕구가 크게 증가하고 있으며, 이에 따라 스마트 헬스케어 산업이 크게 주목받고 있다. 이로 인해 일상생활 중 자신의 건강 상태를 지속적으로 확인하기 위한 원격의료시스템뿐만 아니라, 최근에는 국내외 기업에서 언제 어디서나 신체의 활동 정보를 계측 할 수 있는 웨어러블 디바이스들을 지속적으로 연구개발 및 시장에 선보이고 있다. 특히, 맥파와 심전도는 일상생활 중 자신의 건강상태를 지속적으로 모니터링하기 위한 생체신호로 가장 많이 활용되고 있다. 본 연구에서는 마이크 센서를 활용한 심장의 소리 즉, 심음의 계측을 통해 심장 활동 상태 모니터링이 가능한 시스템을 구현하고자 하며, 상용 전자 청진기과 비교평가를 통해 일상생활 중 지속적인 모니터링이 가능함을 확인 하였다.

• 한국의류산업학회지
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• 제19권6호
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• pp.692-700
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• 2017

The number of elderly citizens has risen in Korea and resulted in an aging society. Correspondingly, the social interest in the aging population has escalated immensely; however, research or product development on the quality of life for seniors has shortcomings. Healthcare smart clothing is required to help the elderly with changes and weaknesses that follow aging; however, there is unfortunately insufficient amounts available. This study explores the feasibilities of smart clothing for seniors based on a universal design. Based on previous research, we analyzed the universal design theory, body shape characteristics and design requirements for seniors, and heart rate measurement method. The design is different according to body shape and body shape is different between sex, age, and body race; therefore, subjects were limited to 70-74 year old Korean males in this study. This study proposes a guideline for heart rate sensing clothing that satisfies the 'universal design' aspects as well as the functionality of heart sensing, senior's physical characteristics and needs. It has broadened the range of smart clothing, which was once limited to the younger generation and provided a foundation for the development of specialized smart clothing for seniors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.42-44
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• 2005

Many cellular phone volunteer studies have been conducted since such a social issue is raised that the long time usage of cellular phone may increase health risk. While there were various volunteer studies using GSM cellular phone on heart rate and blood pressure at abroad, very few studies using CDMA phone were conducted in domestic and abroad. In this study, the volunteer groups of 21 adults were exposed at 300 mW for half an hour, and the physiological parameters such as blood pressure, heart rate, respiration rate, and skin impedance were measured. All the parameters' results did not reveal any differences between exposure and non-exposure conditions in adults.