• 대한의용생체공학회:의공학회지
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• 제35권4호
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• pp.75-80
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• 2014

This paper proposed a method that can automatically classify sleep apnea by using features extracted from pulse rate variability(PRV) signals induced from piezo snoring sensor for patients with obstructive sleep apnea(OSA). We have extracted eight features(NN, SDNN, RMSSD, NN10, NN50, LF, HF and LF/HF ratio) based on time and frequency analyses of PRV. Sleep apnea was classified by a linear discriminant analysis(LDA). A performance was evaluated using snore recordings from 13 patients with OSA (ages: $54.5{\pm}10.5$ years, body mass index: $26.3{\pm}2.5kg/m^2$, apnea-hypopnea index: $19.2{\pm}6.0/h$). The sensitivity and specificity were $78.9{\pm}0.9%$ and $78.9{\pm}0.9%$ for training set and $77.7{\pm}10.9%$ and $79.0{\pm}2.8%$ for test set, respectively. Our study demonstrated the feasibility of implementing a piezo snoring sensor based on a portable device as a simple and cost-effective solution for contributing to the OSA screening.

• 수면정신생리
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• 제15권2호
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• pp.77-81
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• 2008

배 경：수면은 크게 비렘수면(non-REM sleep)과 렘수면(REM sleep)으로 나눌 수 있으며 렘수면 중에는 근력의 소실로 상기도 확장 근육의 긴장도가 저하되고 상기도 저항은 증가하여 무호흡증이 발생하거나 악화될 수 있다. 폐쇄성 수면무호흡증 자체에 대해서는 이미 많은 부분이 알려져 왔으나 렘수면에만 특이적으로 나타나는 렘수면 의존성 폐쇄성 수면무호흡증(REM-dependent OSA)은 그 중요성이 간과되어 왔다. 본 연구에서는 REM-dependent OSA 환자들의 임상 특성과 수면 변인을 살펴보고자 하였다. 방 법：2004년 3월부터 2007년 2월까지 시립은평병원 수면검사실을 방문하여 경도나 중등도의 폐쇄성 수면무호흡증으로 진단받은(5$53.7{\pm}16.7$, 남성：42명)를 대상으로 하였다. REM-dependent OSA(AHIREM/AHINREM${\ge}$2) 환자군과 No REM-dependent OSA(AHIREM/AHINREM<2) 환자군의 임상적 특성과 수면 관련변인을 비교하였다. 통계분석은 Statistica 6.0 프로그램을 사용하였으며, 유의수준은 p<0.05로 하였다. 결 과：대상군 56명 중 21명(37.5%)가 REM-dependent OSA으로 진단되었다. 두 군사이의 연령, 성별, BMI (Body Mass Index)는 유의한 차이를 보이지 않았다. 성별, 연령, BMI, PLMI를 통제한 후, 수면 관련 변인 중 REMdependent OSA 환자군에서 AHI(Apnea Hypopnea Index), ODI(Oxygen Desaturation Index)가 유의하게 낮았다($12.1{\pm}6.4$ vs. $35.9{\pm}24.7$, p=0.010; $6.0{\pm}5.3$ vs. $24.0{\pm}20.4$, p=0.006, respectively, ANCOVA). REMdependent OSA 환자군에서유의하게 높은 2단계 수면이 관찰되었다($58.5{\pm}10.3$ vs. $51.2{\pm}13.2$, p=0.031, ANCOVA). REM-dependent OSA군으로 대상군을 한정하였을 때, 성별, 연령, BMI, PLMI를 통제한 후, 렘수면중 AHI는 전체 수면중 AHI, 비렘수면중 AHI, ODI와 유의미한 양의 상관관계를 보였다(r=0.720, p=0.001；r=750, p=0.001；r=0.749, p=0.001, partial correlation, respectively). 결 론 ：본 연구에서는 폐쇄성 수면무호흡증 환자 중 37.5%를 REM-dependent OSA 환자로 진단할 수 있었다. REM-dependent OSA 환자는 더 경한 정도의 수면 무호흡증을 보이는 경향이 있었으며, 2단계 수면 분율의 증가 같은 수면구조의 변화와 연관되어 있었다. 또한, 렘수면중의 무호흡은 산소포화도 저하와 연관되어 있었다.

• Journal of Oral Medicine and Pain
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• 제47권3호
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• pp.135-143
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• 2022

Purpose: This study aimed to evaluate polysomnographic and cephalometric characteristics of patients with OSA according to obesity level based on the World Health Organization (WHO) Asian-Pacific BMI criteria. Methods: One hundred and thirty-one consecutive patients with obstructive sleep apnea (OSA) were evaluated using standard level 1 polysomnography and cephalometric analyses. The subjects were categorized into normal, overweight and obese groups according to the WHO Asian-Pacific BMI criteria. Respiratory indices and cephalometric parameters were compared among groups. Results: The 131 patients consisted of 111 males and 20 females, with a mean age of 44.1±12.4 years. The mean value of BMI was 25.3±3.4 kg/m² for all subjects, 20.6±2.2 kg/m² for normal (n=27), 24.0±0.5 kg/m² for overweight (n=33) and 27.6±2.2 kg/m² for obese (n=71). The obese group had a significantly higher apnea-hypopnea index (AHI) and respiratory arousal index and lower oxygen saturation level than the normal group (p<0.05). Total AHI, mean oxygen saturation level and respiratory arousal index were significantly correlated with BMI (p<0.001). A longer soft palate and anterior position of the hyoid bone were significantly correlated with BMI level (p ≤0.05). Conclusions: Obese patients have a higher risk of compromised craniofacial skeletal features and soft tissue structures, and severe OSA than non-obese patients.

• Annals of Clinical Neurophysiology
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• 제11권2호
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• pp.54-58
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• 2009

Background: Obstructive sleep apnea (OSA) is associated with several cardiovascular diseases. However, the mechanisms are not completely understood. The measure of common carotid artery intima-media thickness (IMT) has been extensively used as an early marker of atherosclerosis. The aim of this study was to test the hypothesis that early signs of atherosclerosis are present in patients with OSA and correlate with OSA severity Methods: Eleven male patients with OSA were studied by using full standard overnight polysomnography and high-definition echo-tracking device to measure intima-media thickness and carotid artery diameter. Eight healthy volunteers matched for age and sex were studied by portable respiratory monitoring device. All participants were free of hypertension, diabetes, and were not on any medications. Patients with OSA were naive to treatment. Results: All patients and normal controls were male. There was no significant difference of age between patients and controls ($48.4{\pm}8.85$ and $48.0{\pm}9.77$). Significant differences existed between control subjects and patients with mild to moderate and severe OSA (apnea-hypopnea index, $1.51{\pm}1.15$ and $38.51{\pm}19.13$ respectively) in intima-media thickness ($0.59{\pm}0.064$ and $0.93{\pm}0.16$; P=0.0023), and carotid diameter ($5.79{\pm}0.44$ and $6.47{\pm}0.51$; P=0.0227). Multivariate analyses showed that the apnea-hypopnea index correlated independently with intima-media thickness and carotid diameter (r=0.79, P=0.0008, and r=0.47, P=0.0482). Conclusions: Middle-aged patients with OSA who are free of overt cardiovascular diseases have early signs of atherosclerosis, which further supports the hypothesis that OSA plays an independent role in atherosclerosis progression.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권3호
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• pp.161-166
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• 2013

Purpose: This study was intended to perform a cephalometric comparison between the patients with and without obstructive sleep apnea (OSA). The factors influencing the OSA in the lateral cephalogram were also investigated. Methods: Fifty patients who had visited the Sleep Disorder Clinic at the Ajou University Hospital and evaluated with the polysomnograph (PSG) and cephalogram, were included in the study. The patients had the apnea-hypopnea episode over 5 times per hour (apnea-hypopnea index $[AHI]{\geq}5$) were diagnosed as OSA after the overnight PSG. To evaluate the hard and soft tissue profiles, the cephalometric radiograms were taken at the maximal intercuspation. The correlation between the patient's age, height, weight, body mass index (BMI) and AHI was inspected in the OSA and control group. The difference between the OSA and control group was evaluated (Mann-Whitney U Test). The cephalometric influencing factors to OSA were analyzed (Pearson's correlation coefficient) statistically using SPSS statistics. Results: The OSA Group had a significantly higher BMI than the control group. The mean lower facial height (ANS-Me) was longer in the OSA group; however, statistically significant difference was not detected in the anteroposterior craniofacial measurements. The distance between mandibular plane and hyoid bone of the OSA group was significantly longer than that of the control group. The hyoid position (MP-Hyoid) had a positive correlation between AHI (P<0.001). However, the measurements of oropharyngeal airway were not different between the two groups. The hypothesis, that the antero-posteriorly narrow oropharyngeal airway may aggravate the airway resistance and give rise to a higher AHI, was rejected in the study. Conclusion: We suggest that the lateral cephalogram may be utilized as a useful method to evaluate OSA. The patients with a lower hyoid position can be expected to have higher risks of OSA. However, a comprehensive intraoral inspection, including the soft palate and tonsilar hypertrophy, is emphasized, as the lateral cepahlogram cannot visualize the oropharyngeal status completely.

• Journal of Sleep Medicine
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• 제15권2호
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• pp.48-54
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• 2018

Objectives: The aim of this study was to develop a predicting model for the optimal continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA) patient with obesity by using a machine learning. Methods: We retrospectively investigated the medical records of 162 OSA patients who had obesity [body mass index (BMI) ≥ 25] and undertaken successful CPAP titration study. We divided the data to a training set (90%) and a test set (10%), randomly. We made a random forest model and a least absolute shrinkage and selection operator (lasso) regression model to predict the optimal pressure by using the training set, and then applied our models and previous reported equations to the test set. To compare the fitness of each models, we used a correlation coefficient (CC) and a mean absolute error (MAE). Results: The random forest model showed the best performance {CC 0.78 [95% confidence interval (CI) 0.43-0.93], MAE 1.20}. The lasso regression model also showed the improved result [CC 0.78 (95% CI 0.42-0.93), MAE 1.26] compared to the Hoffstein equation [CC 0.68 (95% CI 0.23-0.89), MAE 1.34] and the Choi's equation [CC 0.72 (95% CI 0.30-0.90), MAE 1.40]. Conclusions: Our random forest model and lasso model ($26.213+0.084{\times}BMI+0.004{\times}$apnea-hypopnea index+$0.004{\times}oxygen$ desaturation index-$0.215{\times}mean$ oxygen saturation) showed the improved performance compared to the previous reported equations. The further study for other subgroup or phenotype of OSA is required.

• Journal of Rhinology
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• 제25권2호
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• pp.80-85
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• 2018

Background and Objectives: Obesity is one of the most important risk factors for obstructive sleep apnea (OSA). There is limited evidence regarding the obesity-related anthropometric characteristics of Korean patients. Materials and Method: Medical records of 984 patients referred to 3 tertiary referral hospitals for habitual snoring or sleep apnea were analyzed. We defined OSA as apnea-hypopnea index (AHI) ${\geq}5$ and analyzed data to determine the anthropometric characteristics of patients with OSA such as neck circumference (NC), waist circumference (WC), hip circumference (HC), and waist to hip ratio (WHR). Results: A total of 952 patients (719 men) were included in the analysis. The main findings were: 1) BMI, WC, NC, HC, and WHR were greater among patients with OSA than among controls (AHI <5); 2) for both sexes, the proportion of patients with an OSA diagnosis increased with age; it increased steeply for women aged >50 years; 3) WC and WHR were most strongly correlated with AHI for men and women, respectively. Conclusion: OSA is associated with anthropometric characteristics, although different patterns were observed between men and women. OSA was more strongly associated with NC or WC among men and with WHR among women.

• Journal of Sleep Medicine
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• 제15권2호
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• pp.55-61
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• 2018

Objectives: Despite the accumulating evidence of the effectiveness of positive airway pressure (PAP) therapy in obstructive sleep apnea (OSA) syndrome, adherence to PAP therapy is not high. Several factors reportedly affect PAP adherence; however, it remains unclear whether patients' symptoms were detrimental to adherence rate. This study is aimed at investigating the relationship between insomnia symptoms and adherence. Methods: Retrospective analyses were performed in 359 patients with OSA (mean age $58.4{\pm}13.2$ years; females, n=80). Logistic regression analyses were performed between PAP adherence with clinical factors and questionnaires, such as Epworth Sleepiness Scale, Insomnia Severity Index, and Beck Depression Inventory (BDI). Results: PAP adherence was defined as the use of PAP for ${\geq}4h$ per night on 70% of nights during 30 consecutive days. The median follow-up time was 55 days (interquartile range, 30-119 days), and 54.3% showed poor adherence. Non-adherent patients showed more severe sleep onset insomnia, higher BDI, and higher nadir oxygen saturation ($SaO_2$). Patients with good adherence had higher apnea-hypopnea index, oxygen desaturation index, and respiratory arousal to total arousal ratio. Sleep onset insomnia [odds ratio (OR)=1.792, p=0.012], BDI (OR = 1.055, p=0.026), and nadir $SaO_2$ (OR=1.043, p=0.040) were independently associated with PAP non-adherence. Conclusions: Not the severity of insomnia but sleep onset insomnia was associated with PAP adherence, as well as depressive mood. It suggests that different interventions for reducing insomnia and depressive mood are needed to increase PAP adherence in patients with OSA.

• 수면정신생리
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• 제23권2호
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• pp.97-99
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• 2016

Positive airway pressure (PAP) is currently recommended as a primary treatment for obstructive sleep apnea syndrome (OSAS) and positively affects various subjective and objective parameters related to OSAS, such as the apnea-hypopnea index, excessive daytime sleepiness, and blood pressure. However, PAP also exhibits various adverse effects, including skin breakdown, pressure intolerance, claustrophobia, unintentional mask removal, mouth leaks, and dryness. Especially, unintentional mask removal due to nasal obstruction may result in poor PAP compliance. A 47-year-old male patient with severe OSAS who had low PAP compliance due to nasal obstruction underwent nasal surgery. After the surgery, nasal obstruction was corrected and the patient experienced improved PAP compliance (from 30.4% to 86.7%). This case demonstrates that nasal surgery may be useful for improving PAP compliance in OSAS patients with nasal obstruction.

• 대한치과교정학회지
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• 제41권3호
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• pp.164-173
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• 2011

본 연구는 한국인 성인 폐쇄성 수면무호흡 환자의 남녀 성별차이에 따른 측모 두부방사선계측학적 특성과 관련 요인을 파악하기 위하여 시행되었다. 이를 위하여 계명대학교 의과대학 의료원 수면 클리닉에 수면장애를 주소로 내원하여 수면다원검사 후 치과에서 측모 두부방사선계측사진 촬영을 한 118명의 성인 환자들 중에서 남성 80명과 여성 38명을 각각 수면무호흡지수(apnea-hypopnea index, AHI) 10을 기준으로 단순 코골이군과 폐쇄성 수면무호흡군으로 분류하여 비교하였다. 그 결과, 남성의 경우 단순 코골이군보다 폐쇄성 수면무호흡 환자군의 비만도가 더 높았고, 여성의 경우는 단순 코골이군과 폐쇄성 수면무호흡군 사이의 비만도에서는 유의한 차이가 없었으나 폐쇄성 수면 무호흡군의 평균 연령이 더 높았다. 또한, 남성에서는 연구개의 두께(SPW), 혀 길이(tongue length) 항목이 AHI와 높은 관련성을 보였고, 여성에서는 하악 하연과 설골 간의 거리(MP-Hyoid)만이 관련성을 가지는 것으로 나타났다. 이는 폐쇄성 수면무호흡 환자의 진단과 치료계획 수립 시 남녀 성별차이가 반드시 고려되어야 한다는 것을 의미한다고 볼 수 있겠다.