• Journal of Biomedical Engineering Research
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• v.35 no.4
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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.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.22-29
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• 2001

Objectives: Obstructive sleep apnea syndrome (OSA) is a moderately prevalent disorder. Even though much progress has been made in the diagnosis of this disorder, the cost-effectiveness of nocturnal polysomnography is undertermined and physicians and patients are still hesitant to undergo this procedure. The authors wanted to see the validity of chin press/tongue curl maneuver in estimating the severity of OSA which is easy to measure and was originally proposed by Simmons etc. by looking at the correlations between this score and the conventional respiratory disturbance indices. Methods: Forty-three sleep-related breathing disorder patients (28 OSA patients and 15 upper airway resistance syndrome (UARS) patients) who underwent investigation for posssible OSA were studied. Two conventional indices of OSA (apnea/hypopnea index (AHI) and oxygen saturation dip rate (SaO2 dips)), four other sleep variables (lowest SaO2, % of time with SaO2<90% (%SaO2 <90), % of sleep stage 1, mean length of SaO2 dips) and the score of Epworth sleepiness scale (ESS) were compared with the chin press score (CPS) which was newly revised by the author and ranges from 0 to 6. Results: The age of subjects was $45.95{\pm}12.47$ (range 14-76) and their average BMI was $25.98{\pm}3.61$ (range 19.65-37.64). There were no significant differences in age, sex and BMI except repiratory disturbance indices and ESS (p<0.05) between OSA and UARS group. Grouped median CPS of the all subjects was 4.14 (range 1-6). There was a remarkable relationship between CPS and diagnosis category (Likelihood Ratio $X^2$ test; $X^2$=17.41, df=5, p=0.004) and measures of association (Somers' $d=0.65{\pm}0.12$, t=4.83, p=0.000) indicated that CPS increased when the diagnosis changed from UARS to OSA. Spearman's rank correlations between CPS and SaO2 dips (R=0.83), between CPS and AHI (R=0.77) were good (p<0.001). Other variables except mean length of SaO2 dips showed good correlations with CPS as well (p<0.05). Regression analysis indicated that when CPS is 3 there is a provability of 0.35 to have AHI of less than 5. Conclusion: Chin press scores that can be measured easily is well correlation with the conventional sleep apnea indices. They may therefore provide a useful guide in diagnosing obstructive sleep apnea synrome.

• Sleep Medicine and Psychophysiology
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• v.21 no.1
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• pp.21-28
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• 2014

Objective: Few studies have evaluated the personality characteristics of patients with obstructive sleep apnea (OSA) and simple snoring. We investigated the personality characteristics of OSA and simple snoring patients and compared differences in personality between the two groups using the Eysenck Personality Questionnaire (EPQ). Materials and Methods: Two hundred and thirty-seven patients who were suspected to have OSA or simple snoring participated in this study. A self-questionnaire which included the EPQ was administered to all participants. All subjects underwent polysomnography in a sleep laboratory and those with an apnea-hypopnea index (AHI) ${\geq}5$ were included in the OSA group, while those with an AHI <5 were included in the simple snoring group. Results: OSA patients had significantly lower scores for Psychoticism (F=4.563, p=0.034) than simple snorers. There were no significant differences in Extraversion (F=3.029, p=0.083), Lie (F=0.398, p=0.529), or Neuroticism (F=3.367, p=0.068) scores between the two groups. In the correlation analysis of the OSA group, AHI was positively correlated with Extraversion score (r= 0.16, p=0.029) and negatively correlated with Lie score (B=-0.31, p<0.001). Using multiple stepwise linear regression analysis with the four EPQ parameter scores as dependent variables, Lie score was associated with older age (B=0.14, p<0.001) and lower AHI (B=-0.05, p<0.001), Psychoticism score was associated with higher Pittsburgh Sleep Quality Index (PSQI ; B=0.14, p<0.001), Neuroticism score was associated with higher PSQI (B=0.34, p=0.001) and female sex (B=3.15, p=0.003), and Extraversion score was associated with younger age (B=-0.08, p=0.020) and higher body mass index (B=0.26, p=0.023). Conclusion: This study suggests that patients with OSA are significantly less prone to psychotic personality characteristics than those with simple snoring. Among OSA patients, higher AHI was correlated with low falsehood and high extraversion tendencies.

• Tuberculosis and Respiratory Diseases
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• v.42 no.1
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• pp.84-92
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• 1995

Background: Nasal applied continuous positive airway pressure(CPAP) is a highly effective method of treatment for obstructive sleep apnea syndrome. More than a decade of accumulated experience with this treatment modality confirmed that it is unquestionably the medical treatment of choice for patients with obstructive sleep apnea syndrome. However it takes long time to reach optimal CPAP pressure. To save the time to reach optimal pressure, it is necessary to clarify the time to reach optimal pressure for treatment of obstructive sleep apnea syndrome. Method: CPAP pressure is titrated during an overnight study according to a standardized protocol. Just before the presleep bio-calibration procedures, the technician applies the nasal mask and switches on the clinical CPAP unit. Initial positive for pressure is typically 3.0 centimeters of water pressure. After sleep onset, the technician gradually increases the pressure until sleep-disordered breathing events disappear or become minimal. The pressure must maintain maximal airway patency during both NREM and REM sleep to be considered effective. Before recommending a final pressure setting, sleep recording and oximetry data are reviewed by an American Board of Sleep Medicine certified Sleep Specialist and a Registrered Polysomnographic Technologist. Results: We examined the time required to reach optimal pressure during routine CPAP titration in 127 consecutively evaluated individuals diagnosed with sleep-disordered breathing. Results indicate that 33% of patients required more than four hours to attain satisfactory titration. This indicates that a four-hour session is marginally enough time, at best, to determine a proper CPAP pressure setting. Moreover, 60 of 127 patients required further adjustment after optimal pressure was reached. These additional pressure trials were needed to confirm that higher pressures were not superior for eliminating sleep-disordered breathing events. Conclusions: The data presented underscore the logistical difficulty of titrating CPAP during split-night studies without modifying the titration procedure. Futhermore, the time needed to reach optimal pressure makes it improbable that proper CPAP titration can be performed during a 2-3 hour nap study.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.3
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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.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.3
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• pp.106-110
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• 2014

Obstructive sleep apnea-hypopnea (OSAH) is known to be related to nocturnal blood pressure (BP) and hypertension. The aim of this study was to evaluate the prevalence of hypertension according to the apnea-hypopnea grading. A total of 2,210 adults with snoring and obstructive sleep apnea were referred to our sleep center from July 2009 to May 2013. Clinical blood pressure (BP) was measured before sleeping (bedtime BP) and immediately after waking up in the next morning (morning BP). Subjects were classified into four groups based on the apnea-hypopnea index (AHI) from PSG as follows: control group (n=470) simple snoring and with AHI<5; mild group (n=577) with $AHI{\geq}5$ and <15; moderate group (n=508) $AHI{\geq}15$ and <30; and severe group (n=655) with $AHI{\geq}30$. The differences and correlations between BP and PSG parameters according to the AHI groups were analyzed. Patient's were classified as nomentensive (blood pressure <120/90 mmHg, n=700), prehypertensive (blood pressure < $140-120{\leq}mmHg$, n=1297) hypertensive (blood pressure ${\geq}140/90mmHg$, n=214) according to the office blood pressure measurements. The comparison of sleep parameters showed that OSA groups had a significantly higher stage N1 (control group vs. moderate OSA, severe OSA; $66.4{\pm}30.7$ vs. $85.5{\pm}36.6$, $128.4{\pm}57.3$, p<0.001) and total arousal number (control vs. moderate OSA, severe OSA; $110.7{\pm}47.7$ vs. $150.8{\pm}56.6$, $236.6{\pm}95.8$, p<0.001) compared to control group. The comparison of sleep parameters showed that OSA groups had a significantly lower stage N2 (control group vs. moderate OSA, severe OSA; $172.6{\pm}47.2$ vs. $150.7{\pm}50.5$, $120.3{\pm}57.4$, p<0.001), stage N3 (control group vs. moderate OSA, severe OSA; $38.4{\pm}33.4$ vs. $27.4{\pm}26.0$, $56.1{\pm}27.5$, p<0.001), REM (control group vs. moderate OSA, severe OSA; $64.3{\pm}25.5$ vs. $56.1{\pm}27.5$, $47.3{\pm}25.9$, p<0.001) and mean SaO2% (control group vs. moderate OSA, severe OSA; $90.0{\pm}3.5$ vs. $82.5{\pm}5.5$, $70.0{\pm}8.8$, p<0.001) compared to control group. The Apnea-hypopnea index was significantly higher in OSA groups, increased systolic and diastolic blood pressure than in the nomentensive group (bed time systolic pressure vs. AHI; <120 vs. 120-139, 140-159, >159; $17.5{\pm}18.6$ vs. $24.9{\pm}21.0$, $31.0{\pm}25.7$, $42.3{\pm}31.7$, p<0.001), (bed time diastolic pressure vs. AHI; 60-79 vs. 80-89, 90-99, >99; $19.3{\pm}19.7$ vs. $22.4{\pm}20.3$, $29.8{\pm}23.3$, $38.8{\pm}28.5$, p<0.001). AHI was positively correlated with morning systolic pressure, diastolic pressure, bed time systolic pressure and diastolic pressure (r=0.314, 0.279, 0.233 and 0.200, respectively, p<0.001). We conclude that BMI, Age, neck circumference and AHI increase with the blood pressure.

• The Journal of the Korean dental association
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• v.52 no.10
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• pp.602-614
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• 2014

Obstructive sleep apnea syndrom(OSAS) is defined by total or partial collapse of the upper airway during sleep. In the presence of specific anatomic features, OSAS is potentially amenable to surgical treatment. Initially, the only treatment available for these patients was a tracheotomy that bypassed the obstruction and resulted in a 100% cure. However, this was not readily accepted by most patients, and surgical methods other than tracheotomy were developed to successfully maintain adequate upper airway patency during sleep by comparing to postoperative polysomnography(AHI,RDI etc). In this paper, I would like to provide an overview of some of the multilevel surgical techniques available for treating OSAS as well as the necessary preoperative considerations.

• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.71-76
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• 2008

Introduction: In this study, we compared sleep structure, EEG characteristic of pediatric obstructive sleep apnea (OSA) and normal controls which were matched in sex and age. Methods: Fifteen children (male：female=4：11) who complained snoring and were suspected to have sleep apnea and their age and sex matched normal controls (male：female=5：10) have been done nocturnal polysomnography (NPSG). Sleep parameters, sleep apnea variables and relative spectral components of EEG from NPSG have been compared between both groups. Results: Pediatric OSA group were distinguished from normal controls in terms of apnea index, respiratory disturbance index and nadir of oxyhemoglobulin desaturation. Pediatric OSA group showed increased percent of sleep stage 1, decreased rapid eye movement sleep percent and increased delta power in O1 EEG channel. However other sleep parameters and spectral powers were not different between two groups. Conclusion: In pediatric OSA group, sleep structure parameter disruption may be not prominent as the previous studies for adult OSA group because of including mild OSA data in diagnostic criteria. In addition, EEG changes might not be distinct due to low arousal index compared to adult OSA patients. We can observe general characteristics and particularity of pediatric OSA through this study.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.391-398
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• 2013

Botulinum toxin has been used for treating strabismus, blepharospasm, cerebral palsy, cervical dystonia, hyperhydrosis, facial wrinkle and chronic migraine under US Food and Drug administration approval. Also it has been tried spasticity-induced pain, post-herpetic neuralgia, myofascial pain and aphthous ulcer as off-label use. In this study, we reviewed recent studies that suggested effects of botulinum toxin on snoring and sleep apnea.

• Sleep Medicine and Psychophysiology
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• v.20 no.1
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• pp.31-34
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• 2013

Objectives: The aim of this study was to evaluate the differences in patients with positional dependent sleep apnea according to their non-supine apnea-hypopnea index (AHI, ${\geq}5$ vs. <5). Methods: 92 patients with positional sleep apnea were evaluated. The patients were divided into two groups : group I was non-supine AHI having ${\geq}5$ ; group II was non-supine AHI having less than 5. Statistical analysis was performed to find the difference between two groups. Results: In 92 patients, the number of group I patients was 11 (12%) and the number of group II patients was 81 (88%). In the severe AHI group, percentage of group I was dominated (70%) and showing a significant difference compared with the mild and moderate AHI groups (p<.05). In the severe body mass index (BMI) group, percentage of group I was dominated (54.5%) and showing a significant difference compared with of the mild and moderate BMI groups (p<.05). The percentage of group I was significantly higher than group II (p<.05) in the AHI, supine AHI, non-supine AHI and snore time. Conclusions: In patients with positional sleep apnea, severe OSA and high BMI are more common in patients with non-supine AHI${\geq}5$ than non-supine AHI<5.