{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,24]],"date-time":"2026-02-24T13:36:58Z","timestamp":1771940218754,"version":"3.50.1"},"reference-count":27,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2021,2,16]],"date-time":"2021-02-16T00:00:00Z","timestamp":1613433600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["JP19K17321"],"award-info":[{"award-number":["JP19K17321"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This study aimed to evaluate the capability of a piezoelectric sensor to detect a heart murmur in patients with congenital heart defects. Heart sounds and murmurs were recorded using a piezoelectric sensor and an electronic stethoscope in healthy neonates (n = 9) and in neonates with systolic murmurs caused by congenital heart defects (n = 9) who were born at a hospital. Signal data were digitally filtered by high-pass filtering, and the envelope of the processed signals was calculated. The amplitudes of systolic murmurs were evaluated using the signal-to-noise ratio and compared between healthy neonates and those with congenital heart defects. In addition, the correlation between the amplitudes of systolic murmurs recorded by the piezoelectric sensor and electronic stethoscope was determined. The amplitudes of systolic murmurs detected by the piezoelectric sensor were significantly higher in neonates with congenital heart defects than in healthy neonates (p &lt; 0.01). Systolic murmurs recorded by the piezoelectric sensor had a strong correlation with those recorded by the electronic stethoscope (\u03c1 = 0.899 and p &lt; 0.01, respectively). The piezoelectric sensor can detect heart murmurs objectively. Mechanical improvement and automatic analysis algorithms are expected to improve recording in the future.<\/jats:p>","DOI":"10.3390\/s21041376","type":"journal-article","created":{"date-parts":[[2021,2,16]],"date-time":"2021-02-16T05:02:14Z","timestamp":1613451734000},"page":"1376","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Detection of Pathologic Heart Murmurs Using a Piezoelectric Sensor"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3477-2052","authenticated-orcid":false,"given":"Kiichi","family":"Takahashi","sequence":"first","affiliation":[{"name":"Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita 010-8543, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kyoichi","family":"Ono","sequence":"additional","affiliation":[{"name":"Department of Cell Physiology, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita 010-8543, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hirokazu","family":"Arai","sequence":"additional","affiliation":[{"name":"Department of Neonatology, Akita Red Cross Hospital, 222-1 Nawashirosawa Saruta Kamikitade, Akita 010-1495, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hiroyuki","family":"Adachi","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita 010-8543, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masato","family":"Ito","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita 010-8543, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Akie","family":"Kato","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita 010-8543, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tsutomu","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita 010-8543, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1161\/CIRCRESAHA.112.300853","article-title":"Genetics of congenital heart disease: The glass half empty","volume":"112","author":"Fahed","year":"2013","journal-title":"Circ. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"F46","DOI":"10.1136\/fn.80.1.F46","article-title":"Examination for cardiac malformations at six weeks of age","volume":"80","author":"Gregory","year":"1999","journal-title":"Arch. Dis. Child. Fetal Neonatal Ed."},{"key":"ref_3","first-page":"406","article-title":"Opening Pandora\u2019s box: Parental anxiety and the assessment of childhood murmurs","volume":"18","author":"Giuffre","year":"2002","journal-title":"Can. J. Cardiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"131","DOI":"10.2174\/1573396315666190321105536","article-title":"Cardiac murmurs in children: A challenge for the primary care physician","volume":"15","author":"Kostopoulou","year":"2019","journal-title":"Curr. Pediatr. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"610","DOI":"10.1001\/archinte.166.6.610","article-title":"Competency in cardiac examination skills in medical students, trainees, physicians, and faculty: A multicenter study","volume":"166","author":"Criley","year":"2006","journal-title":"Arch. Intern. Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1298","DOI":"10.1136\/hrt.2005.078097","article-title":"Delayed diagnosis of congenital heart disease worsens preoperative condition and outcome of surgery in neonates","volume":"92","author":"Brown","year":"2006","journal-title":"Heart"},{"key":"ref_7","unstructured":"Volpe, J.J., Inder, T.E., Darras, B.T., de Vries, L.S., du Plessis, A.J., Neil, J.J., and Perlman, J.M. (2017). Preterm intraventricular hemorrhage\/posthemorrhagic hydrocephalus. Volpe\u2019s Neurology of the Newborn, Elsevier. [6th ed.]."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1007\/s11517-006-0047-z","article-title":"System for simultaneously monitoring heart and breathing rate in mice using a piezoelectric transducer","volume":"44","author":"Sato","year":"2006","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"469","DOI":"10.3233\/JAE-2007-751","article-title":"Unconstrained cardiorespiratory monitor for premature infants","volume":"25","author":"Wang","year":"2007","journal-title":"Int. J. Appl. Electromagn. Mech."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1007\/s10015-014-0179-4","article-title":"A noninvasive heartbeat, respiration, and body movement monitoring system for neonates","volume":"19","author":"Nukaya","year":"2014","journal-title":"Artif. Life Robot."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"710","DOI":"10.1111\/apa.13786","article-title":"A systematic review of novel technology for monitoring infant and newborn heart rate","volume":"106","author":"Kevat","year":"2017","journal-title":"Acta Paediatr."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1159\/000283994","article-title":"Assessment of a new piezoelectric transducer sensor for noninvasive cardiorespiratory monitoring of newborn infants in the NICU","volume":"98","author":"Sato","year":"2010","journal-title":"Neonatology"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Wang, J., You, T., Yi, K., Gong, Y., Xie, Q., Qu, F., Wang, B., and He, Z. (2020). Intelligent diagnosis of heart murmurs in children with congenital heart disease. J. Healthc. Eng., 2020.","DOI":"10.1155\/2020\/9640821"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Moon, R.Y., and Task Force on Sudden Infant Death Syndrome (2016). SIDS and other sleep-related infant deaths: Evidence base for 2016 updated recommendations for a safe infant sleeping environment. Pediatrics, 138.","DOI":"10.1542\/peds.2016-2940"},{"key":"ref_15","first-page":"315","article-title":"Improved oxygenation with prone positioning in neonates: Stability of increased transcutaneous PO2","volume":"11","author":"Baird","year":"1991","journal-title":"J. Perinatol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1032","DOI":"10.1152\/jappl.1992.72.3.1032","article-title":"Effect of position on the mechanical interaction be-tween the rib cage and abdomen in preterm infants","volume":"72","author":"Wolfson","year":"1992","journal-title":"J. Appl. Physiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1046\/j.1365-2648.2002.02358.x","article-title":"Effects of prone and supine positions on sleep state and stress responses in mechan-ically ventilated preterm infants during the first postnatal week","volume":"40","author":"Chang","year":"2002","journal-title":"J. Adv. Nurs."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"289","DOI":"10.5014\/ajot.57.3.289","article-title":"Comparison of motor self-regulatory and stress behaviors of preterm infants across body positions","volume":"57","author":"Grenier","year":"2003","journal-title":"Am. J. Occup. Ther."},{"key":"ref_19","first-page":"105","article-title":"Heart sound segmentation algorithm based on heart sound envelogram","volume":"24","author":"Liang","year":"1997","journal-title":"Comput. Cardiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1056","DOI":"10.1016\/j.eswa.2006.12.015","article-title":"Comparison of envelope extraction algorithms for cardiac sound signal segmentation","volume":"34","author":"Choi","year":"2008","journal-title":"Expert Syst. Appl."},{"key":"ref_21","unstructured":"Moukadem, A., Dieterlen, A., and Brandt, C. (2013). Automatic heart sound analysis module based on Stockwell transform. Applied on Auto-Diagnosis and Telemedicine Applications, Proceedings of the 5th International Conference on eHealth, Telemedicine, and Social Medicine (eTELEMED), Nice, France, 24\u201329 February 2013, Curran Associates."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1007\/BF00441529","article-title":"The use of a synthetic skin covering as a protective layer in the daily care of low birth weight infants","volume":"148","author":"Barak","year":"1989","journal-title":"Eur. J. Pediatr."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"752","DOI":"10.1111\/j.1651-2227.1997.tb08580.x","article-title":"Clinical and echocardiographic evaluation of neonates with heart murmurs","volume":"86","author":"Du","year":"1997","journal-title":"Acta Paediatr."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.jsha.2010.03.005","article-title":"Prevalence and clinical significance of heart murmurs detected in routine neonatal examination","volume":"22","author":"Lardhi","year":"2010","journal-title":"J. Saudi Heart Assoc."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2711","DOI":"10.1161\/01.CIR.103.22.2711","article-title":"Artificial neural network-based method of screening heart murmurs in children","volume":"103","author":"DeGroff","year":"2001","journal-title":"Circulation"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1016\/j.artmed.2004.07.008","article-title":"A classifier based on the artificial neural network approach for cardiologic auscultation in pediatrics","volume":"33","author":"Bhatikar","year":"2005","journal-title":"Artif. Intell. Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"386","DOI":"10.1111\/chd.12328","article-title":"Computerized automatic diagnosis of innocent and pathologic murmurs in pediatrics: A pilot study","volume":"11","author":"Lai","year":"2016","journal-title":"Congenit. Heart Dis."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/4\/1376\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:24:42Z","timestamp":1760160282000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/4\/1376"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,2,16]]},"references-count":27,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["s21041376"],"URL":"https:\/\/doi.org\/10.3390\/s21041376","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,2,16]]}}}