{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T23:20:43Z","timestamp":1771024843672,"version":"3.50.1"},"reference-count":17,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,5,8]],"date-time":"2019-05-08T00:00:00Z","timestamp":1557273600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100012331","name":"Agentschap Innoveren en Ondernemen","doi-asserted-by":"publisher","award":["150466"],"award-info":[{"award-number":["150466"]}],"id":[{"id":"10.13039\/100012331","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003132","name":"Agentschap voor Innovatie door Wetenschap en Technologie","doi-asserted-by":"publisher","award":["0184"],"award-info":[{"award-number":["0184"]}],"id":[{"id":"10.13039\/501100003132","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000781","name":"European Research Council","doi-asserted-by":"publisher","award":["339804"],"award-info":[{"award-number":["339804"]}],"id":[{"id":"10.13039\/501100000781","id-type":"DOI","asserted-by":"publisher"}]},{"name":"imec funds 2017","award":["\/"],"award-info":[{"award-number":["\/"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>There exists a technological momentum towards the development of unobtrusive, simple, and reliable systems for long-term sleep monitoring. An off-the-shelf commercial pressure sensor meeting these requirements is the Emfit QS. First, the potential for sleep apnea screening was investigated by revealing clusters of contaminated and clean segments. A relationship between the irregularity of the data and the sleep apnea severity class was observed, which was valuable for screening (sensitivity 0.72, specificity 0.70), although the linear relation was limited (    R 2     of 0.16). Secondly, the study explored the suitability of this commercial sensor to be merged with gold standard polysomnography data for future sleep monitoring. As polysomnography (PSG) and Emfit signals originate from different types of sensor modalities, they cannot be regarded as strictly coupled. Therefore, an automated synchronization procedure based on artefact patterns was developed. Additionally, the optimal position of the Emfit for capturing respiratory and cardiac information similar to the PSG was identified, resulting in a position as close as possible to the thorax. The proposed approach demonstrated the potential for unobtrusive screening of sleep apnea patients at home. Furthermore, the synchronization framework enabled supervised analysis of the commercial Emfit sensor for future sleep monitoring, which can be extended to other multi-modal systems that record movements during sleep.<\/jats:p>","DOI":"10.3390\/s19092133","type":"journal-article","created":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T11:22:35Z","timestamp":1557400955000},"page":"2133","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":41,"title":["Evaluation of a Commercial Ballistocardiography Sensor for Sleep Apnea Screening and Sleep Monitoring"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0500-9894","authenticated-orcid":false,"given":"Dorien","family":"Huysmans","sequence":"first","affiliation":[{"name":"KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing, and Data Analytics, 3001 Leuven, Belgium"},{"name":"IMEC, 3001 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pascal","family":"Borz\u00e9e","sequence":"additional","affiliation":[{"name":"UZ Leuven, Department of Pneumology, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7303-9799","authenticated-orcid":false,"given":"Dries","family":"Testelmans","sequence":"additional","affiliation":[{"name":"UZ Leuven, Department of Pneumology, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bertien","family":"Buyse","sequence":"additional","affiliation":[{"name":"UZ Leuven, Department of Pneumology, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7655-3726","authenticated-orcid":false,"given":"Tim","family":"Willemen","sequence":"additional","affiliation":[{"name":"Equilli, 2800 Mechelen, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5939-0996","authenticated-orcid":false,"given":"Sabine","family":"Van Huffel","sequence":"additional","affiliation":[{"name":"KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing, and Data Analytics, 3001 Leuven, Belgium"},{"name":"IMEC, 3001 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9581-0676","authenticated-orcid":false,"given":"Carolina","family":"Varon","sequence":"additional","affiliation":[{"name":"KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing, and Data Analytics, 3001 Leuven, Belgium"},{"name":"IMEC, 3001 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.smrv.2016.07.002","article-title":"Prevalence of obstructive sleep apnea in the general population: A systematic review","volume":"34","author":"Senaratna","year":"2017","journal-title":"Sleep Med. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1217","DOI":"10.1164\/rccm.2109080","article-title":"Epidemiology of obstructive sleep apnea: A population health perspective","volume":"165","author":"Young","year":"2002","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"479","DOI":"10.5664\/jcsm.6506","article-title":"Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: An American Academy of Sleep Medicine clinical practice guideline","volume":"13","author":"Kapur","year":"2017","journal-title":"J. Clin. Sleep Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/S0924-4247(99)00269-1","article-title":"ElectroMechanical Film (EMFi)\u2014A new multipurpose electret material","volume":"84","author":"Paajanen","year":"2000","journal-title":"Sens. Actuators A Phys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1111\/sbr.12097","article-title":"Apnea during Cheyne-Stokes-like breathing detected by a piezoelectric sensor for screening of sleep disordered breathing","volume":"13","author":"Koyama","year":"2015","journal-title":"Sleep Biol. Rhythm."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/j.resp.2013.03.009","article-title":"Emfit movement sensor in evaluating nocturnal breathing","volume":"187","author":"Tenhunen","year":"2013","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"967","DOI":"10.1016\/j.clinph.2014.08.012","article-title":"Heart rate variability evaluation of Emfit sleep mattress breathing categories in NREM sleep","volume":"126","author":"Tenhunen","year":"2015","journal-title":"Clin. Neurophysiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"597","DOI":"10.5664\/jcsm.2172","article-title":"Rules for scoring respiratory events in sleep: Update of the 2007 AASM manual for the scoring of sleep and associated events","volume":"8","author":"Berry","year":"2012","journal-title":"J. Clin. Sleep Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1109\/TITB.2012.2225067","article-title":"Automatic Detection of Atrial Fibrillation in Cardiac Vibration Signals","volume":"17","author":"Bruser","year":"2013","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Shi, L., Du, L., and Shen, Y.D. (2014, January 14\u201317). Robust Spectral Learning for Unsupervised Feature Selection. Proceedings of the 2014 IEEE International Conference on Data Mining, Shenzhen, China.","DOI":"10.1109\/ICDM.2014.58"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2650","DOI":"10.1109\/TNNLS.2015.2388696","article-title":"Noise Level Estimation for Model Selection in Kernel PCA Denoising","volume":"26","author":"Varon","year":"2015","journal-title":"IEEE Trans. Neural Netw. Learn. Syst."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/0377-0427(87)90125-7","article-title":"Silhouettes: A Graphical Aid to the Interpretation and Validation of Cluster Analysis","volume":"20","author":"Rousseeuw","year":"1987","journal-title":"J. Comput. Appl. Math."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2269","DOI":"10.1109\/TBME.2015.2422378","article-title":"A Novel Algorithm for the Automatic Detection of Sleep Apnea From Single-Lead ECG","volume":"62","author":"Varon","year":"2015","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_14","unstructured":"Willemen, T. (2015). Biomechanics Based Analysis of Sleep. [Ph.D. Thesis, KU Leuven]."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Huysmans, D., Buyse, B., Testelmans, D., Van Huffel, S., and Varon, C. (2018, January 23\u201326). Unsupervised Artefact Detection and Screening Using Emfit Sensor in Patients with Sleep Apnea. Proceedings of the 45th Annual Computing in Cardiology Conference, Maastricht, The Netherlands.","DOI":"10.22489\/CinC.2018.186"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.smrv.2016.10.004","article-title":"Diagnostic accuracy of the Berlin questionnaire, STOP-BANG, STOP, and Epworth sleepiness scale in detecting obstructive sleep apnea: A bivariate meta-analysis","volume":"36","author":"Chiu","year":"2017","journal-title":"Sleep Med. Rev."},{"key":"ref_17","unstructured":"Suykens, J., Alzate, C., and Leuven, K.U. (2011, January 23\u201327). Kernel Spectral Clustering: Model Representations, Sparsity and Out-of-Sample Extensions. Proceedings of the 4th International Conference on Computational Harmonic Analysis, Hong Kong, China."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/9\/2133\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:50:13Z","timestamp":1760187013000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/9\/2133"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,5,8]]},"references-count":17,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2019,5]]}},"alternative-id":["s19092133"],"URL":"https:\/\/doi.org\/10.3390\/s19092133","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,5,8]]}}}