• 대한임상검사과학회지
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• 제39권3호
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• pp.264-270
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• 2007

Obstructive sleep apnea syndrome (OSAS) is defined by sleep apnea with decreased oxygen saturation, excessive snoring with daytime sleepiness, and frequent awakening during the night time sleep. The present study was performed to investigate how apnea-hypopnea, that possibly causes breathing disturbance during sleep, can affect sleep pattern in patients with OSAS. We included 115 patients (92 men, 23 women) who underwent a polysomnography from January 2006 to May 2007. As the frequency of sleep apnea-hypopnea increases, the proportion of non-rapid eye movement (REM) sleep (p<0.001), and stage I sleep (p<0.001) increased, while that of stage II sleep (p<0.001), stage III and IV sleep (p<0.01), and REM sleep (p<0.05) decreased. Furthermore, sleep apnea-hypopnea was closely correlated with REM sleep (r=0.314, p<0.001), stage I sleep (r=0.719, p<0.001), stage II sleep (p=-0.342, p<0.05), stage III and IV sleep (r=-0.414, p<0.001), and REM sleep (r=-0.342, p<0.05). Stage I sleep could account for the 51% of the variance of apnea-hyponea. Our study shows sleep apnea-hypopnea affects sleep pattern in pattern with OSAS significantly, and the change of stage I sleep is the most important factor in estimating the disturbance of sleep pattern.

• 수면정신생리
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• 제17권1호
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• pp.11-15
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• 2010

Obstructive sleep apnea is a common sleep disorder that predominantly affects adult men than women. However, the prevalence in women increases with menopause dramatically. Menopause has long been described as a risk factor for obstructive sleep apnea. Recent large well-designed population studies support that menopause increases the risk for sleep-disordered breathing. The mechanism of that hypothesis is not yet clear. But, the decline in progesterone has been thought to influence the development of obstructive sleep apnea because progesterone is a respiratory stimulant and plays a protective role against sleep apnea. Increased visceral obesity and hypertension as major symptoms of metabolic syndrome are also associated with menopause and place women at increased risk for obstructive sleep apnea and other serious health problem. Hormone replacement therapy has been associated with a lower prevalence of sleep apnea. But, relative risk and benefits of hormone replacement therapy compared with other treatment options will require thorough consideration for each individual woman. Finally, attention should be drawn to the need for obstructive sleep apnea evaluation in perimenopausal and postmenopausal women.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.605-608
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• 2011

In this study, OSA (the obstructive sleep apnea) periods were detected in patients with OSA during sleep because of the treatment was different according to the frequency and symptoms of obstructive sleep apnea. ANS (autonomic nervous activity) was changed by obstructive sleep apnea periods so we intended to detect the periods to care the obstructive sleep apnea patients. RR intervals, SDNN (standard deviation of normal to normal) and RMSSD (root mean square standard deviation) were calculated in time domain analysis and LF (low frequency), HF (high frequency), NHF (normalized high frequency), NLF (normalized low frequency) were calculated in frequency domain analysis of HRV (heart rate variability) with obstructive sleep apnea patients. In this paper, SDNN (standard deviation of normal to normal) of time domain analysis were decreased in the obstructive sleep apnea periods. And NLF and LF/HF ratio were increased and NHF (normalized high frequency) was decreased in the frequency domain analysis. The parameters can be used to treat obstructive sleep apnea patients by detecting the obstructive sleep apnea periods such as CPAP (continuous positive airway pressure).

• 수면정신생리
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• 제5권2호
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• pp.177-184
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• 1998

Objectives : Disturbance of sleep with or without sleep apnea may impair the memory function. Sleep deficiency, sleepiness, sleep apnea and emotional problem in sleep disorders can induce an impairment of memory function. Methods : In this study, the polysomnographies were administered to 58 sleep apnea patients and 38 sleep disorder patients without sleep apnea. Their clinical symptoms were quantitatively evaluated. Short term and long term memory were evaluated before and after polysom no graphy with Digit symbol test and Rey-Osterrieth complex figure test. And correlations among various sleep, repiratory and clinical variables were statistically studied in order to explore which variables may influence on memory function. Results and Conclusions : Results are as follows. Depth of sleep cis positively correlated with memory function. As sleep apnea increases and average saturation of blood oxygen decreases, memory function is more impaired. Emotional depression, high blood pressure, obesity or alcohol impaired memory function. However, daytime sleepiness was not significantly correlated with memory function. The possible mechanisms how above factors influence on the memory function were discussed.

• 수면정신생리
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• 제7권2호
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• pp.79-83
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• 2000

Sleep disturbances are frequently associated with neurological disorders. Sleep disorders interfere with rehabilitation of patients with neurological disorders such as stroke and may increase the severity of their symptoms and recurrence rate of stroke. The treatment of sleep apnea syndrome is particularly important in managing patients with cerebral infarction of whom 50-80% have moderate to severe sleep apnea. Sleep apnea produces not only poor quality sleep but also excessive daytime sleepiness, fatigue and lack of energy. Sleep problems frequently found in patients with dementia are sleep-wake cycle abnormality, fragmentation of sleep, nocturnal insomnia, decreased slow wave sleep and REM sleep, and sleep disordered breathing. The management of sleep disturbances is very important for controlling symptoms such as nocturnal wandering and sundowning syndrome in patients with dementia. Parkinson's disease and epilepsy are other neurological disorders that may have sleep disturbances.

• 수면정신생리
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• 제17권2호
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• pp.69-74
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• 2010

Obstructive sleep apnea syndrome is associated with significant cardiovascular morbidity and increased mortality. However, it was controversial whether obstructive sleep apnea syndrome could cause pulmonary hypertension. The controversy was resolved by several studies that have shown pulmonary hypertension in 20% to 40% of patients with obstructive sleep apnea syndrome without underlying other cardiopulmonary diseases and reductions in pulmonary arterial pressure in patients with obstructive sleep apnea syndrome after treatment with nocturnal continuous positive airway pressure. Recent studies provide strong evidence for endothelial dysfunction in obstructive sleep apnea syndrome and pulmonary hypertension. Endothelin-1 is a 21 amino acid peptide with diverse biologic activity such as highly potent vasoconstrictor and mitogen regulator that may play a key role in obstructive sleep ap-nea syndrome and pulmonary hypertension. Continuous positive airway pressure therapy is moderately effective in reducing pulmonary arterial pressure. Further researches are needed to assess the therapeutic efficacy of pharmacologic therapy with agents that inhibit the action of endothelin-1 in obstructive sleep apnea syndrome patients with pulmonary hypertension.

• 수면정신생리
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• 제1권1호
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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.

• 한국산업정보학회논문지
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• 제22권1호
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• pp.41-51
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• 2017

This Paper Describes a Method for the Evaluation of Sleep Apnea, Namely, the Peak Signal-to-noise ratio (PSNR) of Wavelet Transformed Electroencephalography (EEG) Data. The Purpose of this Study was to Investigate EEG Properties with Regard to Differences between Sleep Spindles and K-complexes and to Characterize Obstructive Sleep Apnea According to Sleep Stage. We Examined Non-REM and REM Sleep in 20 Patients with OSA and Established a New Approach for Detecting Sleep Apnea Base on EEG Frequency Changes According to Sleep Stage During Sleep Apnea Events. For Frequency Bands Corresponding to A3 Decomposition with a Sampling Applied to the KC and the Sleep Spindle Signal. In this Paper, the KC and Sleep Spindle are Ccalculated using MSE and PSNR for 4 Types of Mother Wavelets. Wavelet Transform Coefficients Were Obtained Around Sleep Spindles in Order to Identify the Frequency Information that Changed During Obstructive Sleep Apnea. We also Investigated Whether Quantification Analysis of EEG During Sleep Apnea is Valuable for Analyzing Sleep Spindles and The K-complexes in Patients. First, Decomposition of the EEG Signal from Feature Data was Carried out using 4 Different Types of Wavelets, Namely, Daubechies 3, Symlet 4, Biorthogonal 2.8, and Coiflet 3. We Compared the PSNR Accuracy for Each Wavelet Function and Found that Mother Wavelets Daubechies 3 and Biorthogonal 2.8 Surpassed the other Wavelet Functions in Performance. We have Attempted to Improve the Computing Efficiency as it Selects the most Suitable Wavelet Function that can be used for Sleep Spindle, K-complex Signal Processing Efficiently and Accurate Decision with Lesser Computational Time.

• 대한의용생체공학회:의공학회지
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• 제34권2호
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• pp.97-103
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• 2013

This paper proposes a new algorithm for sleep apnea detection based on stroke volume. It is very important to detect sleep apnea since it is a common and serious sleep-disordered breathing (SDB). In the previous studies, methods for sleep apnea detection using heart rate variability, airflow and blood oxygen saturation, tracheal sound have been proposed, but a method using stroke volume has not been studied. The proposed algorithm consists of detection of characteristic points in continuous blood pressure signal, estimation of stroke volume and detection of sleep apnea. To evaluate the performance of algorithm, the MIT-BIH Polysomnographic Database provided by Phsio- Net was used. As a result, the sensitivity of 85.99%, the specificity of 72.69%, and the accuracy of 84.34%, on the average were obtained. The proposed method showed comparable or higher performance compared with previous methods.

• 수면정신생리
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• 제1권2호
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• pp.163-171
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• 1994

연구목적 : 수면 무호흡의 증상은 크게 불면증, 낮의 과다한 졸리움, 기억력과 집중력 등의 인지기능장애, 우울 등의 감정장애 등이 주 증상을 이루고 있다. 그런데 이러한 증상들이 수면 및 수면 무호홉의 여러 변수들과 어떤 상관관계를 가지며 어떤 과정을 통해서 구체적으로 발생되는 지에 대한 연구는 그렇게 많지 않다. 연구방법 : 본 연구는 수면 무호흡증 환자 60 명을 대상으로 수면다원검사를 실시함과 동시에 낮 졸리움 척도, 불면증 척도, 인지기능 척도 및 감정장애 척도를 통해 수면 무호홉의 증상을 평가하였다. 그리고 수면다원 검사상의 여러 수면변수, 무호흡의 횟수, $O_2$ desaturation, 코골기 정도 등과 무호흡 증상의 4 가지 척도와 상관관계를 조사하였다. 연구결과 : 유의한 상관관계를 보인 결과는 다음과 같다. 무호흡 환자 중 불면증호소가 적고 비교적 잠을 잘 자는 경우는 호흡장애가 많은 경우와 중심성 무호흡이 많은 경우였다. 그리고 제 3 단계 서파수면에서 코골기가 많거나 경등도의 산소저하가 많은 경우였다. 대신 낮에 졸리움증이 많은 경우는 제 1 단계에서 코골기가 많은 경우였다. 그러나 무호흡의 정도나 산소와는 직접 상관관계가 나타나지는 않았다. 우울 등의 감정장애는 수면 중 산소저하가 중등도이상으로 심한 경우 많이 나타났으며 제 4 단계 서파수면이 적은 경우 이러한 우울 감정이 더 심하게 나타났다. 집중과 기억 등의 인지기능은 REM 수면이 많고 호흡장애의 횟수가 적을수록 더욱 감소되는 현상을 보였다. 결론 : 무호흡의 증상은 서로 다른 원인과 기전을 통해 발생될 수 있으며 이러한 증상을 좀 더 객관적 평가할 수 있다면 환자의 수면 및 무호흡의 정도와 상태를 예측하는데 더욱 많은 도움을 줄 수 있을 것으로 기대된다.