• Sleep Medicine and Psychophysiology
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• v.1 no.1
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• pp.60-67
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• 1994

Objectives: The Obstructive sleep apnea syndrome is characterized by snoring, observed apnea during sleep and excessive daytime sleepiness. The overnight polysomnographic recording is used to investigate patients with possible obstructive sleep apnea syndrome. But the overnight polysomnographic recording is time consuming, expensive, and labor-intensive. Recently in diagnosis of obstructive sleep apnea syndrome, several simple screening tests have been suggested. Methods: This study was performed to assess the probability of application of clinical features and the degree of oxygen desaturation as a screening test for the obstructive sleep apnea syndrome. The sensitivity and specificity of the self-report of clinical features including snoring, observed apnea during sleep, excessive daytime sleepiness and insomnia were tested. And the degree of oxygen desaturation measured by oximetry in 42 subjects were compared with the overnight polysomnographic recording results. Results: In the prediction of apnea index more than 5, the sensitivity of observed apnea during sleep, snoring, excessive daytime sleepiness and insomnia were 96.8%, 93.5%, 38.7%, 25.8% and the specificity of those clinical features were 182%, 36.4%, 100%, 72.7%, respectively. In the prediction of apnea index more than 5, the sensitivity and specificity of the combination of more than three self-report clinical features were 54.8% and 90.9%. The degree of oxygen de saturation and maximal apnea duration in the group of apnea index more than 5 were significantly different from those in the group of apnea index below 5(P<0.001). And the apnea index was significantly correlated with the degree of oxygen desaturation and maximal apnea duration(P<0.001). Conclusion: These results suggest that application of clinical features alone as a screening test for the obstructive sleep apnea syndrome is inadequate because of it's high rate of false positive and false negative results. The degree of oxygen desaturation measured by oximetry is possibly applicable to screening test and follow up evaluation of treatment efficacy for the obstructive sleep apnea syndrome.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.47-52
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• 2005

Obstructive Sleep Apnea (OSA) is a representative symptom of sleep disorder caused by the obstruction of upper airway. Because OSA causes not only excessive daytime sleepiness and fatigue, hypertension and arrhythmia but also cardiac arrest and sudden death during sleep in the severe case, it is very important to detect the occurrence and the frequency of OSA. OSA is usually diagnosed through the laboratory-based Polysomnography (PSG) which is uncomfortable and expensive. Therefore researches to improve the disadvantages of PSG are needed and studies for the detection of OSA using only one or two parameters are being made as alternatives to PSG. In this paper, we developed an algorithm for the detection of OSA based on Heart Rate Variability (HRV). The proposed method is applied to the ECG data sets provided from PhysioNet which consist of learning set and training set. We extracted features for the detection of OSA such as average and standard deviation of 1 minute R-R interval, power spectrum of R-R interval and S-peak amplitude from data sets. These features are applied to the input of neural network. As a result, we obtained sensitivity of $89.66\%$ and specificity of $95.25\%$. It shows that the features suggested in this study are useful to detect OSA.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.278-283
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• 2020

Central sleep apnea (CSA) is characterized by respiratory failure of at least 10 seconds without any effort of the chest and abdomen in the absence of upper airway resistance during sleep. In this case, the patient experiences respiratory failure that does not meet the CSA diagnostic criteria and CSA symptoms. Magnetic resonance imaging diffusion-weighted imaging (MRI DWI) scans revealed a lateral medullary infarction. Continuous positive airway pressure (CPAP) was applied as a primary treatment for CSA and respiratory failure. During the titration of CPAP, the apnea-hypopnea index (AHI) and arousal index (AI) were worse than the results before its use (AHI: 42.5/hr→82.8/hr, AI: 21.7/hr→40.8h). As a result, adaptive servo-ventilation (ASV) was chosen as the secondary treatment. Compared to the night-polysomnography results before the ASV treatment, the AHI improved (42.5/hr→8.6/hr). Therefore, ASV is a potential treatment for CSA and respiratory failure in these patients.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.126-134
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• 2015

A sleep disorder is being recognized as one of the major health issues related to high levels of stress. At the same time, interests about quality of sleep are rapidly increasing. However, diagnosing sleep disorder is not a simple task because patients should undergo polysomnography test, which requires a long time and high cost. To solve this problem, an accelerometer embedded wrist-worn device is being considered as a simple and low cost solution. However, conventional methods determine a state of user to "sleep" or "wake" according to whether values of individual section's accelerometer data exceed a certain threshold or not. As a result, a high miss-classification rate is observed due to user's intermittent movements while sleeping and tiny movements while awake. In this paper, we propose a novel method that resolves the above problems by employing a dynamic classifier which evaluates a similarity between the neighboring data scores obtained from SVM classifier. A performance of the proposed method is evaluated using 50 data sets and its superiority is verified by achieving 88.9% accuracy, 88.9% sensitivity, and 88.5% specificity.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.68-71
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• 2005

We report a case of obstructive sleep apnea syndrome, which occurred primarily during the REM sleep stage. A 55-year-old female patient who complained of chronic insomnia on the initial visit turned out to have obstructive sleep apnea syndrome of a mild degree (respiratory disturbance index (RDI) of 13.8/hour, %time spent below 90% of SaO2=5.0%) on nocturnal polysomnography. Interestingly, apnea episodes and desaturations mainly occurred during REM sleep stage. And RDI and destaturations during REM sleep stage were found to be severe enough to classify as a severe degree of obstructive sleep apnea syndrome. These findings suggest that severe obstructive sleep apnea syndrome might be masked under the symptom of chronic insomnia and that apneas can be predominantly localized within REM sleep epochs. In terms of treatment, "REM sleep-dependent" apneas may call for different methods of treatment, especially REM sleep-specific pharmacological intervention.

• Sleep Medicine and Psychophysiology
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• v.17 no.2
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• pp.85-90
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• 2010

Objectives: Ginseng has a long history of being used in insomnia treatment and there is some evidence from animal studies of its sleep-enhancing property. From this, it can be assumed that ginseng has sleep-promoting effect in humans. The purpose of this study was to investigate the effect of Korean red ginseng on change of sleep architecture in humans. Methods: A total of 20 healthy young males with regular sleep and wake habits and without any psychiatric nor cognitive problems were selected based on review of sleep questionnaires and sleep diaries they completed followed by an interview with a board-certified psychiatrist. The subjects were randomly assigned to red ginseng or placebo for 2 weeks of trial. The total daily dose of ginseng was 4,500 mg. The polysomnographic recordings were made at baseline and at 2 weeks after. The effects of red ginseng and placebo on sleep were assessed by comparing the changes in polysomnographic variables between the two groups. Results: A total of 15 subjects, 8 from red ginseng group and 7 from placebo group, were included to undergo polysomnographic procedures. The red ginseng group showed tendencies to increase stage 3 sleep (p=0.087) and to decrease stage 2 sleep (p=0.071) from the baseline compared with the placebo group. Conclusion: Korean red ginseng tends to increase deep sleep and decrease shallow sleep. Our result is in line, at least in part, with previous findings that Korean red ginseng increased total and NREM sleep in rats. Further studies with higher ginseng dosage, larger sample size and longer trial duration should be conducted to confirm the sleep stabilizing and balancing effects of Korean red ginseng.

• Sleep Medicine and Psychophysiology
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• v.14 no.1
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• pp.42-48
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• 2007

Introduction: Detrended fluctuation analysis (DFA) is used as a way of studying nonlinearity of EEG. In this study, DFA is applied on sleep EEG of normal subjects to look into its nonlinearity in terms of EEG channels and sleep stages. Method: Twelve healthy young subjects (age：$23.8{\pm}2.5$ years old, male：female=7：5) have undergone nocturnal polysomnography (nPSG). EEG from nPSG was classified in terms of its channels and sleep stages and was analyzed by DFA. Scaling exponents (SEs) yielded by DFA were compared using linear mixed model analysis. Results: Scaling exponents (SEs) of sleep EEG were distributed around 1 showing long term temporal correlation and self-similarity. SE of C3 channel was bigger than that of O1 channel. As sleep stage progressed from stage 1 to slow wave sleep, SE increased accordingly. SE of stage REM sleep did not show significant difference when compared with that of stage 1 sleep. Conclusion: SEs of Normal sleep EEG showed nonlinear characteristic with scale-free fluctuation, long-range temporal correlation, self-similarity and self-organized criticality. SE from DFA differentiated sleep stages and EEG channels. It can be a useful tool in the research with sleep EEG.

• Korea Journal of Hospital Management
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• v.25 no.3
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• pp.67-77
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• 2020

Background: As of 2016, average Koreans sleep 7 hours and 42 minutes, the lowest figure among Organization for Economic Cooperation and Development(OECD) countries, and the number of people with sleep disorders reached 561,000. Accordingly, the government has promoted the provision of 'Multiple Sleep Test' to strengthen the diagnosis service for patients with 'sleep disorder' in july 2018. As a result, healthcare costs for patients with sleep disorder is on the rise every year. In this study, we utilized 'Appropriate Sleep' criteria of United States's National Sleep Foundation(NSF) then investigated Korean's sleep pertinence using ｢7th National Health and Nutrition Survey for 2016-2018」 by different occupational type, demographic characteristics, socio-economic characteristics, and health behaviors. Methods: We performed descriptive analysis to examine differences of sleep appropriateness by various sample characteristics. Multivariate logistic regression models were used to examine sleep appropriateness by occupational type and other variables. We also analyzed subgroup models to investigate. Results: As a result, a total of 1,948 (18.37%) study subjects experienced in-appropriate sleep. Results of the Multivariate logistic regression analysis revealed that blue color group had a higher odds ratio (OR) for experiencing in-appropriate sleep (OR=1.179). In addition, the odds ratio of experienced in-appropriate sleep among the elderly aged 70 and over was 2.698, and the odds ratio of the overstressed group was 1.299. Furthermore, sub-group analysis showed that blue color job of female(Or=1.334), high school or below(OR=1.404), divorce/death/separation(OR=2.039), 25%ile-50%lie income group(OR=1.411) more likely experienced in-appropriate sleep. Conclusion: Growing sleep disorder patients and related health care costs are expected. Government should apply detailed 'total periodic sleep disorder management policy' including pre-consultation, examination, diagnosis, treatment, post-consultation, self-management especially to vulnerable population that this study found.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.610-617
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• 1995

Sleep apnea occurs in approximately 50% of patients with acromegaly, and sleep apnea is associated with increased cardiovascular diseases and mortality. In view of these findings, sleep apnea may be a factor in the increased incidence of cardiovascular deaths in acromegaly patients. We experienced a case of active acromegaly patient, 54-yr-old man, associated with obstructive sleep apnea syndrome, congestive heart failure with dilated cardiomyopathy and serious cardiac arrhythmias. He was treated for obstructive sleep apnea syndrome, diagnosed by overnight polysomnography, with nasal continuous positive airway pressure(CPAP) for 4 months, which successfully controlled his loud snoring, sleep apnea, nocturnal hypoxemia and apnea-related symptoms. And also he was treated for underlying acromegaly and cardiac complications with bromocriptine and cardiogenic drugs for 4 months, but still had elevated growth hormone(GH) and insulin like growth factor-1(IGF-1) levels and serious cardiac arrhythmias. We describe our experience about the effect of CPAP treatment in an active acromegaly patient associated with obstructive sleep apnea syndrome and cardiac complications with review of literature.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.457-464
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• 1998

This report describes a 5-month follow-up of the efficacy of Herbst oral appliance(OA) in a obstructive sleep apnea syndrome patient who has failed with uvulopalatopharyngoplasty(UPPP) and was unable to tolerate to subsequent nasal continuous positive airway pressure(CPAP) because of mouth air leak. The obstructive sleep apnea and daytime performance were markedly improved by regular home use of OA, and the patient still continues to use OA without complications. It is suggested that OA can be a successful alternative therapeutic modality in patients who are unable to tolerate to nasal CP AP, especially after UPPP.