{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:39:43Z","timestamp":1760243983804,"version":"build-2065373602"},"reference-count":19,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2009,4,14]],"date-time":"2009-04-14T00:00:00Z","timestamp":1239667200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper the use of a continuous-wave microwave sensor as a non-contact tool for quantitative measurement of respiratory tidal volume has been evaluated by experimentation in seventeen healthy volunteers. The sensor working principle is reported and several causes that can affect its response are analyzed. A suitable data processing has been devised able to reject the majority of breath measurements taken under non suitable conditions. Furthermore, a relationship between microwave sensor measurements and volume inspired and expired at quiet breathing (tidal volume) has been found.<\/jats:p>","DOI":"10.3390\/s90402574","type":"journal-article","created":{"date-parts":[[2009,4,15]],"date-time":"2009-04-15T07:11:34Z","timestamp":1239779494000},"page":"2574-2585","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":51,"title":["Non-Contact Detection of Breathing Using a Microwave Sensor"],"prefix":"10.3390","volume":"9","author":[{"given":"Devis","family":"Dei","sequence":"first","affiliation":[{"name":"Department of Electronics and Telecommunications, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gilberto","family":"Grazzini","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guido","family":"Luzi","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3661-726X","authenticated-orcid":false,"given":"Massimiliano","family":"Pieraccini","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Carlo","family":"Atzeni","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sergio","family":"Boncinelli","sequence":"additional","affiliation":[{"name":"Department of Medical and Surgical Critical Area, University of Florence, Viale Morgagni 85, 50134 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gianna","family":"Camiciottoli","sequence":"additional","affiliation":[{"name":"Unit of Respiratory Physiopathology, University of Florence, Viale Morgagni 85, 50134 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Walter","family":"Castellani","sequence":"additional","affiliation":[{"name":"Unit of Respiratory Physiopathology, University of Florence, Viale Morgagni 85, 50134 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Massimo","family":"Marsili","sequence":"additional","affiliation":[{"name":"Department of Medical and Surgical Critical Area, University of Florence, Viale Morgagni 85, 50134 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juri","family":"Lo Dico","sequence":"additional","affiliation":[{"name":"Department of Medical and Surgical Critical Area, University of Florence, Viale Morgagni 85, 50134 Firenze, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2009,4,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"959","DOI":"10.1016\/S0140-6736(71)90274-1","article-title":"Contactless apnoea detector based on radar","volume":"2","author":"Caro","year":"1971","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"838","DOI":"10.1109\/TMTT.2004.823552","article-title":"Correlation and I\/Q Performance Benefits in Single-Chips Silicon Doppler Radars for Noncontact Cardiopulmonary Monitoring","volume":"52","author":"Droitcour","year":"2004","journal-title":"IEEE Trans. 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