{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,1]],"date-time":"2026-03-01T00:40:24Z","timestamp":1772325624497,"version":"3.50.1"},"reference-count":21,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2015,7,7]],"date-time":"2015-07-07T00:00:00Z","timestamp":1436227200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Ministry of Science and Technology, Taiwan","award":["NSC 99-2221-E-182-017-MY3"],"award-info":[{"award-number":["NSC 99-2221-E-182-017-MY3"]}]},{"name":"the Chang Gung Memorial Hospital, Taoyuan, Taiwan","award":["CMRPD1C0202"],"award-info":[{"award-number":["CMRPD1C0202"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Impedance plethysmography provides a way to measure respiratory activity  by sensing the change of thoracic impedance caused by inspiration and expiration. This measurement imposes little pressure on the body and uses the human body as the sensor, thereby reducing the need for adjustments as body position changes and making it suitable for long-term or ambulatory monitoring. The empirical mode decomposition (EMD) can decompose a signal into several intrinsic mode functions (IMFs) that disclose nonstationary components as well as stationary components and, similarly, capture respiratory episodes from thoracic impedance. However, upper-body movements usually produce motion artifacts that are not easily removed by digital filtering. Moreover, large motion artifacts disable the EMD to decompose respiratory components. In this paper, motion artifacts are detected and replaced by the data mirrored from the prior and the posterior before EMD processing. A novel intrinsic respiratory reconstruction index that considers both global and local properties of IMFs is proposed to define respiration-related IMFs for respiration reconstruction and instantaneous respiratory estimation. Based on the experiments performing a series of static and dynamic physical activates, our results showed the proposed method had higher cross correlations between respiratory frequencies estimated from thoracic impedance and those from oronasal airflow based on small window size compared to the Fourier transform-based method.<\/jats:p>","DOI":"10.3390\/s150716372","type":"journal-article","created":{"date-parts":[[2015,7,8]],"date-time":"2015-07-08T10:10:02Z","timestamp":1436350202000},"page":"16372-16387","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":41,"title":["Instantaneous Respiratory Estimation from Thoracic Impedance by Empirical Mode Decomposition"],"prefix":"10.3390","volume":"15","author":[{"given":"Fu-Tai","family":"Wang","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, Hwa Hsia University of Technology, 111, Gongzhuan Rd., Zhonghe, New Taipei City 23568, Taiwan"}]},{"given":"Hsiao-Lung","family":"Chan","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Chang Gung University, 259 Wenhwa 1st Road, Kweishan, Taoyuan 33302, Taiwan"}]},{"given":"Chun-Li","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Chang Gung Memorial Hospital, 5 Fu-Hsing Street, Kweishan,  Taoyuan 33305, Taiwan"}]},{"given":"Hung-Ming","family":"Jian","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Chang Gung University, 259 Wenhwa 1st Road, Kweishan, Taoyuan 33302, Taiwan"}]},{"given":"Sheng-Hsiung","family":"Lin","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Chang Gung University, 259 Wenhwa 1st Road, Kweishan, Taoyuan 33302, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2015,7,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1093\/sleep\/32.2.150","article-title":"The new Aasm criteria for scoring hypopneas: Impact on the apnea hypopnea index","volume":"32","author":"Ruehland","year":"2009","journal-title":"Sleep"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1463","DOI":"10.1378\/chest.07-0121","article-title":"Daytime Cheyne-Stokes respiration in ambulatory patients with severe congestive heart failure is associated with increased mortality","volume":"132","author":"Brack","year":"2007","journal-title":"Chest"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1435","DOI":"10.1161\/01.CIR.99.11.1435","article-title":"Prognostic value of nocturnal Cheyne-Stokes respiration in chronic heart failure","volume":"99","author":"Lanfranchi","year":"1999","journal-title":"Circulation"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1098\/rspa.1998.0193","article-title":"The empirical decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis","volume":"454","author":"Huang","year":"1998","journal-title":"Proc. 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