{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T10:07:22Z","timestamp":1775815642000,"version":"3.50.1"},"reference-count":40,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2015,1,12]],"date-time":"2015-01-12T00:00:00Z","timestamp":1421020800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Obstructive sleep apnea (OSA) is an independent cardiovascular risk factor to which autonomic nervous dysfunction has been reported to be an important contributor. Ninety subjects recruited from the sleep center of a single medical center were divided into four groups: normal snoring subjects without OSA (apnea hypopnea index, AHI &lt; 5,  n = 11), mild OSA (5 \u2264 AHI &lt; 15, n = 10), moderate OSA (15 \u2264 AHI &lt; 30, n = 24), and severe OSA (AHI \u2265 30, n = 45). Demographic (i.e., age, gender), anthropometric (i.e., body mass index, neck circumference), and polysomnographic (PSG) data were recorded and compared among the different groups. For each subject, R-R intervals (RRI) from 10 segments of 10-minute electrocardiogram recordings during non-rapid eye movement sleep at stage N2 were acquired and analyzed for heart rate variability (HRV) and sample entropy using multiscale entropy index (MEI) that was divided into small scale (MEISS, scale 1\u20135) and large scale (MEILS, scale 6\u201310). Our results not only demonstrated that MEISS could successfully distinguish normal snoring subjects and those with mild OSA from those with moderate and severe disease, but also revealed good correlation between MEISS and AHI with Spearman correlation analysis (r = \u22120.684, p &lt; 0.001). Therefore, using the two parameters of EEG and ECG, MEISS may serve as a simple preliminary screening tool for assessing the severity of OSA before proceeding to PSG analysis.<\/jats:p>","DOI":"10.3390\/e17010231","type":"journal-article","created":{"date-parts":[[2015,1,12]],"date-time":"2015-01-12T13:30:46Z","timestamp":1421069446000},"page":"231-243","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Multiscale Entropy Analysis of Heart Rate Variability for Assessing the Severity of Sleep Disordered Breathing"],"prefix":"10.3390","volume":"17","author":[{"given":"Wen-Yao","family":"Pan","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, National Dong Hwa University, Hualien, 97401, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mao-Chang","family":"Su","sequence":"additional","affiliation":[{"name":"Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine,  Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2581-9384","authenticated-orcid":false,"given":"Hsien-Tsai","family":"Wu","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, National Dong Hwa University, Hualien, 97401, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Meng-Chih","family":"Lin","sequence":"additional","affiliation":[{"name":"Sleep Center, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"I-Ting","family":"Tsai","sequence":"additional","affiliation":[{"name":"Department of Emergency Medicine, E-Da hospital, I-Shou University College of Medicine, Kaohsiung, 82445, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cheuk-Kwan","family":"Sun","sequence":"additional","affiliation":[{"name":"Department of Emergency Medicine, E-Da hospital, I-Shou University College of Medicine, Kaohsiung, 82445, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,1,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1136\/thorax.2003.015859","article-title":"Sleep 2: Pathophysiology of obstructive sleep apnoea\/hypopnoea syndrome","volume":"59","author":"Fogel","year":"2004","journal-title":"Thorax"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"793","DOI":"10.1378\/chest.07-0800","article-title":"Obstructive sleep apnea: Implications for cardiac and vascular disease","volume":"133","author":"Gami","year":"2008","journal-title":"Chest"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1016\/S0272-5231(21)00873-X","article-title":"Hypertension, cardiac arrhythmias, myocardial infarction, and stroke in relation to obstructive sleep apnea","volume":"13","author":"Shepard","year":"1992","journal-title":"Clin. 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