• Science of Emotion and Sensibility
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• v.23 no.2
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• pp.51-60
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• 2020

This study aimed to develop a modular smart clothing system for heart rate monitoring that reduces the inconvenience caused by battery charging and the large size of measurement devices. The heart rate monitoring system was modularized into a temporary device and a continuous device to enable heart rate monitoring depending on the requirement. The temporary device with near-field communication (NFC) and heart rate sensors was developed as a clothing attachment type that enables heart rate monitoring via smart phone tagging when required. The continuous device is based on Bluetooth Low Energy (BLE) communication and batteries and was developed to enable continuous heart rate measurement via a direct connection to the temporary device. Furthermore, the temporary device was configured to connect with a textile electrode made of a silver-based knitted fabric designed to be located below the pectoralis major muscle for heart rate measurement. Considering the user-experience factors, key functions, and the ease of use, we developed an application to automatically log through smart phone tagging to improve usability. To evaluate the accuracy of the heart rate measurement, we recorded the heart rate of 10 healthy male subjects with a modular smart clothing system and compared the results with the heart rate values measured by the Polar RS800. Consequently, the average heart rate value measured by the temporary system was 85.37, while that measured by the reference device was 87.03, corresponding to an accuracy of 96.73%. No significant difference was found in comparison with the reference device (T value = -1.892, p = .091). Similarly, the average heart rate measured by the continuous system was 86.00, while that measured by the reference device was 86.97, corresponding to an accuracy of 97.16%. No significant difference was found in terms of the heart rate value between the two signals (T value = 1.089, p = .304). The significance of this study is to develop and validate a modular clothing system that can measure heart rates according to the purpose of the user. The developed modular smart clothing system for heart rate monitoring enables dual product planning by reducing the price increase due to unnecessary functions.

• Journal of Korean Academy of Nursing
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• v.13 no.3
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• pp.119-126
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• 1983

Early extra-uterine development of the newborn infant has the potential for clarifying important questions of nature and care taking environment. In this study, tactile and auditory stimulation is used on .a group of infants to determine the effects of their response. Infants were tested by EKG at 24∼48 hrs after birth ana all they are free from complication. Stimuli presented were-touch and sound (40dB, 70dB and 40∼70dB). The result of the study were as follows: 1) The heart rate was seen to depend on their sleep-wake state. (light sleep ; 125/min, eyes: open & motor activity increase ； 151/min crying ; 185/min). 2) The heart rate affected by tactile & auditory stimulus. The heart rate response was acceleration above the prestimulus level. (tactile, 231min increase, auditory ; 16∼21/min increase), and heart rate change was seen to depend on prestimulus rate. (γ=.73) 3) There was a decrease in heart rate when they were soothe. (touch ; 24.8sec, 21/min decrease, pacifier ; 14.5sec, 26/min decrease) and significant difference in time between touch and pacifier (t= 1.76, p<0.05). This result support the evaluation of newborn infant's sensory abilitics, and has even begin to influence changes in nursing care. But systemic monitoring of newborn infants response would. further define.

• Journal of Acupuncture Research
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• v.25 no.2
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• pp.189-197
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• 2008

Objectives : This study was performed in order to investigate the effectiveness of electromyography and the Heart Rate Variability(HRV) test as prognosis factors, and to clarify correlation between Electromyography and the Heart Rate Variability test. Methods : 44 Bell's palsy patients who were graded V on the House-Brackmann scale and underwent HRV and EMG testing were retrospectively reviewed based on medical records. Results from both tests were analyzed via simple linear regression, and bivariate correlation analysis was performed to investigate the correlation between results from the two tests. The severity of the facial palsy at onset and at 2 weeks after treatment were evaluated with the H-B grade and Yanagihara grading system, and was converted into improvement scores. Results : Mean axonal loss according to electromyography showed a statistically significant correlation in predicting peripheral facial palsy improvement(p<0.01). HR, SDNN, TP, LF, HF, VLF, and LF/HF ratio on the Heart Rate Variability test showed no significant correlation in predicting peripheral facial palsy improvement. Mean axonal loss determined by electromyography, and HR, SDNN, TP, LF, HF, VLF, and LF/HF ratio recorded with the Heart Rate Variability test was analyzed with the bivariate correlation analysis method. Mean axonal loss and SDNN showed a statistically significant correlation(p<0.01) Conclusions : The Heart Rate Variability test has no statistical significance in predicting peripheral facial palsy improvement. SDNN has a statistically significant correlation with mean axonal loss as determined by electromyography.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.3
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• pp.109-115
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• 2011

Objectives: To characterize autonomic dysfunction in patients with Cold hypersensitivity, their heart rate variability(HRV) were measured and analyzed with cold hypersensitivity patients, compared with those of normal population. Methods: We studied 56 patients visiting Gangnam Kyung-hee korean hospital from 1st January 2010 to 31th December 2010. Heart rate variability were obtained from 28 female patients who suffer from cold hypersensitivity and 28 healthy female controls in resting state. We studied the difference of Heart rate variability between two groups by Independent T-test using SPSS for windows(version 17.0). Results: Standard deviation of NN interval(SDNN), total power(TP), Very low frequency(VLF) in patients with cold hypersensitivity were significantly different with those of controls. While no significant differences were observed in square root of mean squared differences of successive NN intervals (RMSSD), low frequency (LF) and high frequency(HF). Conclusions: The decreased values of heart rate variability(HRV) study means that they may have some kinds of imbalance in autonomic nervous system in cold hypersensitivity patients. heart rate variabiliry(HRV) study might be a tool of diagnosis and predictors in cold hypersensitivity patients.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.461-463
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• 2002

Image quality and selection of optimized window for good quality reconstruction in coronary angiography using multi-detector row CT (MDCT) have not been studied by heart rate and its variation. Therefore, the effect of heart rate and its variation was systemically analyzed. Eighty-three patients were undergone contrast-enhanced coronary angiography using MDCT. In this study, sixty cases were enrolled. Two radiologists graded image quality as follows: 4, excellent; 3, good; 2, fair; l, bad. The starting points of the reconstruction window were chosen at seventy and forty percent of R wave interval. Optimized window was scored as 1 when 40% reconstruction was better quality than 70%, as 2 when 40% reconstruction is same as 70%, and as 3 when 70% reconstruction was better than 40%. Regression analysis was performed. The range of variation of beats per minute (BPM) was well correlated with image quality (r=-0.55, p=0.000), however correlation with optimized window percentage was not statistically significant (p=0.969). By contraries, median value of BPM was comparatively well correlated with optimized window grade (r=-0.24, p=0.086). Median value of BPM was not well correlated with image quality (r=0.l70, p=0.l97). Image quality is more affected by variation of heart rate (VHR) than by higher heart rate. Selection of optimized reconstruction window for good image quality is mainly affected by heart rate and there is a tendency that systolic phase reconstruction is better in image quality than diastolic reconstruction in higher heart rate.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.8
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• pp.18-26
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• 2015

Measuring the heart rate during exercise is important to properly control the amount of exercise. With the recent advent of smart device usage, there is a dramatic increase in interest in devices for the real-time measurement of the heart rate during exercise. During intensive exercise, accurate heart rate estimation from wrist-type photoplethysmography (PPG) signals is a very difficult problem due to motion artifact (MA). In this study, we propose an efficient algorithm for an accurate estimation of the heart rate from wrist-type PPG signals. For the twelve data sets, the proposed algorithm achieves the average absolute error of 1.38 beat per minute (BPM) and the Pearson correlation between the estimates and the ground-truth of heart rate was 0.9922. The proposed algorithm presents the strengths in an accurate estimation together with a fast computation speed, which is attractive in application to wearable devices.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.128-133
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• 2003

Stimulus effects of strobe light on jack mackerel Trachurus japonicus were studied by measuring the heart rate change according to the different strobe light intensity of 5~75 lx$\cdot$s. Heart rate was observed for 60 min: 10 min before, 30 min during and 20 min after the strobe light stimulus. The measurement of heart rate was repeated three times at 2 hour intervals. The results showed that the heart rate increased during stimulus but temporarily decreased immediately after ending of stimulus. The heart rate changes in both during and after stimulus were decreased with reducing light intensities. The heart rate change according to the repeated experiment was not remarkably different under the lower light intensity

• Child Health Nursing Research
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• v.21 no.3
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• pp.195-203
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• 2015

Purpose: This study was done to investigate quality of sleep and heart rate variability by the physical activity in high school students. Methods: A survey that measures physical activity and quality of sleep was distributed to 118 students at Y High School. Heart rate variability was obtained using the LXC3203 heart rate monitor. The data of 105 students were analyzed using descriptive statistics, t-test, x2-test, and ANOVA with $Scheff{\acute{e}}$ test. Results: Boys and students with part-time jobs had significantly higher physical activity. The quality of sleep was significantly high when the students were non-smokers, felt healthy, happy, less stressed, and satisfied with their school lives. Mean heart rate was significantly higher among girls, and standard deviation from normal to normal R-R intervals were high in boys. Physical activity had no significant relationships with quality of sleep and heart rate variability. Conclusions: Physical activity should be encouraged for high school students, especially for girls. An experimental study with different intensity and time of physical activity is recommended to examine the relationships with quality of sleep and heart rate variability in the future.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.181-184
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• 2004

There are reports showing that electromagnetic fields (EMFs) emitted at non-thermal levels may be associated with biological alterations in target cells. In this study it is objected to assess the potential influences of EMFs produced by cellular phones on fetal heart rate. Non Stress Test (NST) is a widely used method of fetal monitoring and assessing fetal health and well-being. Sixty volunteers with uncomplicated term pregnancies were studied by a Spacelabs AM-67 Doppler ultrasound monitor. Fetal Heart Rate recordings were obtained while there were no Cellular Phone around for 10 minutes. Afterwards, all patients were exposed to EMFs for 10 minutes. NST was performed while they were holding the CP on stand-by mode and then on dialing mode, each for 5 minutes. The recordings were analyzed with respect to baseline heart rate, accelerations and decelerations. The Wilcoxon matched-pairs signed-ranks test was used to compare these variables. The results indicate that EMFs emitted by CP do not cause any demonstrable effects on baseline FHR, acceleration or deceleration.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1978_1979
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• 2009

Heart rate may be a very important parameter in human health. To extract heart rate, the electrocardiogram(ECG) is commonly used. But the ECG acquisition procedure is somewhat complex. On the other hand, the acquisition of pulse wave or photoplethysmogram(PPG) is very easy. However, the peak of PPG is not so sharp as ECG. This study tries to enhance the performance of period detection in PPG signal. The method uses the average slopes around the main peak. The crossing point of the increasing and the decreasing slopes is selected as the peak point of heart rate period. The proposed method showed smoothed heart rate graph and reduced irregularity in heart rate values.