• Journal of Korean Academy of Nursing
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• v.41 no.6
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• pp.788-794
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• 2011

Purpose: Reduced heart rate variability significantly increases cardiovascular mortality. Metabolic syndrome increases the cardiac autonomic dysfunction. Recently, increasing cardiovascular mortality has been reported in patients with schizophrenia. This study was done to compare heart rate variability between adults with and without schizophrenia and to compare the relationship of heart rate variability to metabolic syndrome in hospitalized patients with schizophrenia. Methods: This was a descriptive and correlational study in which 719 adults without schizophrenia and 308 adults with schizophrenia took part between May and June 2008. We measured the following: five-minute heart rate variability; high-frequency, low-frequency, the ratio of low-frequency to high-frequency, and the Standard Deviation of all the normal RR intervals. Data was also collected on metabolic syndrome, abdominal obesity, triglycerides, HDL cholesterol, blood pressure and fasting glucose. Results: The Standard Deviation of all the normal RR intervals values of heart rate variability indices were $1.53{\pm}0.18$. The low-frequency and high-frequency values of heart rate variability indices were significantly higher in hospitalized patients with schizophrenia ($3.89{\pm}1.36$; $3.80{\pm}1.20$) than those in the healthy participants ($2.20{\pm}0.46$; $2.10{\pm}0.46$). There were no significant differences between the schizophrenic patients with and without metabolic syndrome. Conclusion: The results of this study indicate that schizophrenia patients have significantly lower cardiac autonomic control, but they have significantly higher low-frequency and high-frequency values than those of healthy adults. Use of antipsychotic drug may affect the autonomic nervous system in schizophrenic patients. Metabolic syndrome was not associated with cardiac autonomic control in schizophrenia patients.

• Biomedical Science Letters
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• v.19 no.1
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• pp.70-78
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• 2013

This study was conducted to identify the effects of intake of beta-blocker and aerobic exercise on heart rate recovery (HRR) and exercise capacity after maximal exercise in acute coronary syndrome patients (ACS). Subjects were divided into 4 groups; Beta-blocker-Exercise group (n=10), Beta-blocker group (n=10), Exercise group (n=10), Control group (n=10). Symptom-limited grade exercise test were conducted on subjects pre- and post- 6 week study, to measure maximal heart rate, heart rate at 1 minute and 2 minutes at the recovery stage, maximal oxygen uptake and maximal exercise time. Study resulted in significant improvements in heart rate recovery for BB-Ex group ($17.40{\pm}5.58$ bpm to $26.10{\pm}6.66$ bpm), maximal oxygen uptake for BB-Ex group ($30.46{\pm}8.63$ to $36.33{\pm}8.10$) and Ex group ($29.04{\pm}4.93$ to $34.31{\pm}5.19$), and total exercise time for BB-Ex group ($906.30{\pm}158.57$ to $1018.50{\pm}151.21$), BB group ($805.70{\pm}182.94$ to $897.50{\pm}160.16$) and Ex group ($870.00{\pm}145.63$ to $961.90{\pm}107.29$). Therefore it showed the biggest improvement for heart rate recovery and exercise capacity in acute coronary syndrome patients when both Beta-blocker and aerobic exercise were in effect.

• The Journal of Korean Medicine
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• v.33 no.4
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• pp.50-59
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• 2012

Objectives: This study aimed to compare the effects of high frequency electroacupuncture, low frequency electroacupuncture and manual acupuncture on the autonomic nervous system in stroke patients by using a heart rate variability measuring device. Methods: Thirty-nine participants were recruited and each participated in the high frequency electroacupuncture group, low frequency electroacupuncture group, manual acupuncture group and non-acupuncture group. Some participants received needle insertion with 100 Hz stimulation, with 2Hz stimulation and manual stimulation under mental arithmetic stress during 2 sections. Other participants maintained in the supine position without acupuncture under mental arithmetic stress during the 2 sections. Acupuncture needles were directly inserted perpendicularly to the right Liv 3 acupoint followed by delivery of electric pulses to these points for 8 minutes. Heart rate variability was measured 8 minutes before and 16 minutes after acupuncture stimulation by a heart rate variability measuring system. Results: We found a significant elevated HF total power between 1 section and 2 section and between 1 section and 4 section in the non-acupuncture group, between 3 section and 4 section in the 100Hz electroacupuncture group, and between 1 section and 2 section in the manual acupuncture group and with no change in the 2Hz electroacupuncture group. We also found a significant VLF total power between 2 section and 3 section in the 2Hz electroacupuncture group and between 1 section and 4 section and between 2 section and 4 section in the 100Hz electroacupuncture group. All four groups showed no significant differences in other parameters including heart rate mean, low-frequency power, and the ratio of low-frequency power to high-frequency power. Conclusions: This study may be a basis for research about effects of acupuncture and electroacupuncture because the parameters measured, heart rate variability, showed differences according to acupuncture.

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1481-1491
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• 2021

Since most biosignals rely on contact-based measurement, there is still a problem in that it is hard to provide convenience to users by applying them to daily life. In this paper, we present a mobile application for estimating heart rate based on a deep learning model. The proposed application measures heart rate by capturing real-time face images in a non-contact manner. We trained a three-dimensional convolutional neural network to predict photoplethysmography (PPG) from face images. The face images used for training were taken in various movements and situations. To evaluate the performance of the proposed system, we used a pulse oximeter to measure a ground truth PPG. As a result, the deviation of the calculated root means square error between the heart rate from remote PPG measured by the proposed system and the heart rate from the ground truth was about 1.14, showing no significant difference. Our findings suggest that heart rate measurement by mobile applications is accurate enough to help manage health during daily life.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.323-324
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• 2007

• Biomedical Science Letters
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• v.24 no.2
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• pp.130-133
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• 2018

The aim of this study was to evaluate the protective function of fisetin, a natural flavonoid in zebrafish heart for the treatment of myocardial infarction in coronary and ischemic heart disease. For this purpose, we induced oxidative stress zebrafish (Danio rerio)-Tg (cmlc2: egfp) by $H_2O_2$ and then administered fisetin, the protective effect of fisetin was determined by measuring the heart rate following fisetin administration. After testing the toxicity of fisetin, we found that the heartt increased in a concentration-dependent manner, however there was no difference between the heart rates of embryos and adults. The improved heart rate demonstrated the cardioprotective effect of fisetin. The result showed that fisetin, at concentration of 3and $5{\mu}M$, significantly increased heart rate compared with the heart with $H_2O_2$ alone. This indicates that fisetin plays an important role in the prevention of heart damage and treatment of cardiovascular diseases caused by oxidative stress due to ischemia / reperfusion.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.4
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• pp.167-174
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• 2002

This study describes a fetal heart rate(FHR) estimation algorithm using phonogram. Using a phonogram amplifier, various fetal heart sounds are collected in a university hospital. The FHR estimation algorithms consists of a lowpass filter, decimation, envelop detection, pitch detection, and post-processing. The post-processing is the FHR decision procedure using all informations of fetal heart rates. Using the algorithm and other parameters of fetal heart sound, a fetal monitoring software was developed. This can display the original signals, the FFT spectra, FHR and its trajectory. Even though the fetal phonogram amplifier detects the fetal heart sounds well, the sound quality is not so good as the ultrasonography. In case of very week fetal heart sound, autocorrelation of it showed clear periodicity. But two main peaks in one period is an obstacle in pitch detection and peaks are not so vivid. The proposed FHR estimation algorithm showed very accurate and stable results. Since the developed software displays multiple parameters in real time and has convenient functions, it will be useful for the phonogram-style fetal monitoring device.

• Journal of Chest Surgery
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• v.13 no.3
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• pp.167-173
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• 1980

From 1976 through June 1980, 75 patients underwent Open heart operation at Korea University Hospital.Of the 75 patients, 39 were congenital heart cases and 36 were acquired heart disease cases. 39 cases of congenital heart disease were consisting of 16 T.O.F.,4 A.S.D., 10 V.S.D., 3 P.S., 1 P.D.A., 1 V.S.D. + Mi, 1 Truncus arteriosus, 1 Ebstein, 1 D.C.R.V., 1 Single ventricle. Among 36 valvular replacement cases, 18 cases of MVR, 3 cases of AVR, 6 cases of Double valve replacement, and 10 cases of Open Mitral commissurotomy, were performed. Postoperative mortality rate of congenital heart disease was 25.6% and that of acquired heart disease was 8.3%. Overall mortality rate of open heart surgery was 17.3%. Among 16 cases of postoperative death cases, 5 cases of autopsy were performed. Postoperative cause of death of our series were intracranial bleeding, pacemaker failure, low output syndrome, protamine anaphylaxis, bleeding, prosthetic valve embolism, C V A, miliary tuberculosis, hypothermia due to pump failure.

• Women's Health Nursing
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• v.8 no.2
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• pp.151-164
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• 2002

PURPOSE: Estrogen replacement therapy is indicated for the relief of hot flushes and urogenital atrophy, the prevention of osteoporosis and the reduction in risk of cardiovascular disease. The present study assessed by blood pressure, heart rate variability, and climacteric symptoms in menopausal women before treatment and at 1 month during estrogen replacement therapy. METHODS: The study sample consisted of 16 healthy menopausal women (range 49 to 59 years, mean : 53.4 years) attending menopausal clinics for the complaint of climateric symptoms at S. hospital in Chunchoen. They were all non-smokers and no patient had symptoms or evidence of cardiovascular disease. They took estrogen replacement therapy (conjugated estrogen 0.625 mg with or without medroxy progesteron 2.5mg) for 1 month. Blood pressure, heart rate variability(heart period and vagal tone) through ECG, and climacteric symptom were measured in all subjects before treatment and at 1 month during treatment. Climacteric symptom questionnaire which was developed by Neugarten et al.(1963) was modified with 20 items of question(Cronbach's alpha = 88 -.89). The data was collected from Sept. 1. 2000 to July. 30. 2001. RESULTS: There was no significant difference in mean systolic and diastolic pressure between the baseline and at 1 month during treatment. The mean heart period and vagal tone were slightly increased, but difference of mean heart period and vagal tone were not statistically significant between the baseline and at 1 month during treatment. The score of climacteric symptoms decreased significantly from the baseline after treatment. CONCLUSIONS: Even though, this study did not show that estrogen replacement therapy led decrease of blood pressure and increase heart rate variability, climacteric symptoms reduced much in all subjects after taking drugs. These results suggest that there is need to repeat study with long term period.

• Child Health Nursing Research
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• v.6 no.1
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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.