{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T15:53:13Z","timestamp":1780501993416,"version":"3.54.1"},"reference-count":38,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2023,11,17]],"date-time":"2023-11-17T00:00:00Z","timestamp":1700179200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency","doi-asserted-by":"publisher","award":["JPMJCE1312"],"award-info":[{"award-number":["JPMJCE1312"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Techniques for noninvasively acquiring the vital information of infants and young children are considered very useful in the fields of healthcare and medical care. An unobstructive measurement method for sleeping infants and young children under the age of 6 years using a sheet-type vital sensor with a polyvinylidene fluoride (PVDF) pressure-sensitive layer is demonstrated. The signal filter conditions to obtain the ballistocardiogram (BCG) and phonocardiogram (PCG) are discussed from the waveform data of infants and young children. The difference in signal processing conditions was caused by the physique of the infants and young children. The peak-to-peak interval (PPI) extracted from the BCG or PCG during sleep showed an extremely high correlation with the R-to-R interval (RRI) extracted from the electrocardiogram (ECG). The vital changes until awakening in infants monitored using a sheet sensor were also investigated. In infants under one year of age that awakened spontaneously, the distinctive vital changes during awakening were observed. Understanding the changes in the heartbeat and respiration signs of infants and young children during sleep is essential for improving the accuracy of abnormality detection by unobstructive sensors.<\/jats:p>","DOI":"10.3390\/s23229252","type":"journal-article","created":{"date-parts":[[2023,11,17]],"date-time":"2023-11-17T10:10:06Z","timestamp":1700215806000},"page":"9252","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Unobstructive Heartbeat Monitoring of Sleeping Infants and Young Children Using Sheet-Type PVDF Sensors"],"prefix":"10.3390","volume":"23","author":[{"given":"Daisuke","family":"Kumaki","sequence":"first","affiliation":[{"name":"Research Center for Organic Electronics, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Yamagata, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuko","family":"Motoshima","sequence":"additional","affiliation":[{"name":"Faculty of Education, Art and Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata City 990-8560, Yamagata, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fujio","family":"Higuchi","sequence":"additional","affiliation":[{"name":"Research Center for Organic Electronics, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Yamagata, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katsuhiro","family":"Sato","sequence":"additional","affiliation":[{"name":"Research Center for Organic Electronics, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Yamagata, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomohito","family":"Sekine","sequence":"additional","affiliation":[{"name":"Research Center for Organic Electronics, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Yamagata, Japan"},{"name":"Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Yamagata, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shizuo","family":"Tokito","sequence":"additional","affiliation":[{"name":"Research Center for Organic Electronics, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Yamagata, Japan"},{"name":"Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Yamagata, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1109\/JSEN.2010.2089510","article-title":"Film-type sensor materials PVDF and EMFi in measurement of cardiorespiratory signal\u2014A review","volume":"12","author":"Rajala","year":"2012","journal-title":"IEEE Sens. 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