{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T16:13:08Z","timestamp":1780503188204,"version":"3.54.1"},"reference-count":32,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2022,12,8]],"date-time":"2022-12-08T00:00:00Z","timestamp":1670457600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Research and Development Project","award":["2019YFC0119800"],"award-info":[{"award-number":["2019YFC0119800"]}]},{"name":"National Key Research and Development Project","award":["20210302124203"],"award-info":[{"award-number":["20210302124203"]}]},{"name":"National Key Research and Development Project","award":["20210302123027"],"award-info":[{"award-number":["20210302123027"]}]},{"name":"National Key Research and Development Project","award":["52175553"],"award-info":[{"award-number":["52175553"]}]},{"name":"National Key Research and Development Project","award":["61927807"],"award-info":[{"award-number":["61927807"]}]},{"name":"Fundamental Research Program of Shanxi Province","award":["2019YFC0119800"],"award-info":[{"award-number":["2019YFC0119800"]}]},{"name":"Fundamental Research Program of Shanxi Province","award":["20210302124203"],"award-info":[{"award-number":["20210302124203"]}]},{"name":"Fundamental Research Program of Shanxi Province","award":["20210302123027"],"award-info":[{"award-number":["20210302123027"]}]},{"name":"Fundamental Research Program of Shanxi Province","award":["52175553"],"award-info":[{"award-number":["52175553"]}]},{"name":"Fundamental Research Program of Shanxi Province","award":["61927807"],"award-info":[{"award-number":["61927807"]}]},{"name":"National Natural Science Foundation of China","award":["2019YFC0119800"],"award-info":[{"award-number":["2019YFC0119800"]}]},{"name":"National Natural Science Foundation of China","award":["20210302124203"],"award-info":[{"award-number":["20210302124203"]}]},{"name":"National Natural Science Foundation of China","award":["20210302123027"],"award-info":[{"award-number":["20210302123027"]}]},{"name":"National Natural Science Foundation of China","award":["52175553"],"award-info":[{"award-number":["52175553"]}]},{"name":"National Natural Science Foundation of China","award":["61927807"],"award-info":[{"award-number":["61927807"]}]},{"name":"National Natural Science Foundation of China as the National Major Scientific Instruments Development Project","award":["2019YFC0119800"],"award-info":[{"award-number":["2019YFC0119800"]}]},{"name":"National Natural Science Foundation of China as the National Major Scientific Instruments Development Project","award":["20210302124203"],"award-info":[{"award-number":["20210302124203"]}]},{"name":"National Natural Science Foundation of China as the National Major Scientific Instruments Development Project","award":["20210302123027"],"award-info":[{"award-number":["20210302123027"]}]},{"name":"National Natural Science Foundation of China as the National Major Scientific Instruments Development Project","award":["52175553"],"award-info":[{"award-number":["52175553"]}]},{"name":"National Natural Science Foundation of China as the National Major Scientific Instruments Development Project","award":["61927807"],"award-info":[{"award-number":["61927807"]}]},{"name":"Shanxi 1331 Project Key Subject Construction and Innovation Special Zone Project","award":["2019YFC0119800"],"award-info":[{"award-number":["2019YFC0119800"]}]},{"name":"Shanxi 1331 Project Key Subject Construction and Innovation Special Zone Project","award":["20210302124203"],"award-info":[{"award-number":["20210302124203"]}]},{"name":"Shanxi 1331 Project Key Subject Construction and Innovation Special Zone Project","award":["20210302123027"],"award-info":[{"award-number":["20210302123027"]}]},{"name":"Shanxi 1331 Project Key Subject Construction and Innovation Special Zone Project","award":["52175553"],"award-info":[{"award-number":["52175553"]}]},{"name":"Shanxi 1331 Project Key Subject Construction and Innovation Special Zone Project","award":["61927807"],"award-info":[{"award-number":["61927807"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>In light of a need for low-frequency, high sensitivity and broadband cardiac murmur signal detection, the present work puts forward an integrated MEMS-based heart sound sensor with a hollow concave ciliary micro-structure. The advantages of a hollow MEMS structure, in contrast to planar ciliated micro-structures, are that it reduces the ciliated mass and enhances the operating bandwidth. Meanwhile, the area of acoustic-wave reception is enlarged by the concave architecture, thereby enhancing the sensitivity at low frequencies. By rationally designing the acoustic encapsulation, the loss of heart acoustic distortion and weak cardiac murmurs is reduced. As demonstrated by experimentation, the proposed hollow MEMS structure cardiac sound sensor has a sensitivity of up to \u2212206.9 dB at 200 Hz, showing 6.5 dB and 170 Hz increases in the sensitivity and operating bandwidth, respectively, in contrast to the planar ciliated MEMS sensor. The SNR of the sensor is 26.471 dB, showing good detectability for cardiac sounds.<\/jats:p>","DOI":"10.3390\/mi13122174","type":"journal-article","created":{"date-parts":[[2022,12,9]],"date-time":"2022-12-09T02:20:31Z","timestamp":1670552431000},"page":"2174","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Design and Fabrication of an Integrated Hollow Concave Cilium MEMS Cardiac Sound Sensor"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0422-2634","authenticated-orcid":false,"given":"Bo","family":"Wang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pengcheng","family":"Shi","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuhua","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6572-2045","authenticated-orcid":false,"given":"Jiangong","family":"Cui","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guojun","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Renxin","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1762-9246","authenticated-orcid":false,"given":"Wendong","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9897-1718","authenticated-orcid":false,"given":"Changde","family":"He","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yirui","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuotong","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, School of Instrument and Electronics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"183","DOI":"10.2147\/JMDH.S193904","article-title":"The first 200 years of cardiac auscultation and future perspectives","volume":"12","author":"Montinari","year":"2019","journal-title":"J. Multidiscip. Healthc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1001\/jama.1985.03360010134047","article-title":"Understanding heart sounds and murmurs, with an introduction to lung sounds","volume":"254","author":"Resnekov","year":"1985","journal-title":"JAMA"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Redlarski, G., Gradolewski, D., and Palkowski, A. (2014). A system for heart sounds classification. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0112673"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Zhang, G., Liu, M., Guo, N., and Zhang, W. (2016). Design of the MEMS piezoresistive electronic heart sound sensor. Sensors, 16.","DOI":"10.3390\/s16111728"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"906","DOI":"10.1016\/j.patcog.2007.07.018","article-title":"Heart sound as a biometric","volume":"41","author":"Phua","year":"2008","journal-title":"Pattern Recognit."},{"key":"ref_6","first-page":"786","article-title":"Monitoring of respiration, seismocardiogram and heart sounds by a PVDF piezo film sensor","volume":"11","author":"Bifulco","year":"2014","journal-title":"Measurement"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e1601185","DOI":"10.1126\/sciadv.1601185","article-title":"Epidermal mechano-acoustic sensing electronics for cardiovascular diagnostics and human-machine interfaces","volume":"2","author":"Liu","year":"2016","journal-title":"Sci. Adv."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"106","DOI":"10.3109\/03091902.2016.1139203","article-title":"Performance analysis of seismocardiography for heart sound signal recording in noisy scenarios","volume":"40","author":"Jain","year":"2016","journal-title":"J. Med. Eng. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Anumukonda, M., and Chowdhury, S.R. (2017). Heart sound sensing through MEMS microphone. Sensors for Everyday Life, Springer.","DOI":"10.1007\/978-3-319-47319-2_7"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Fattah, S.A., Rahman, N.M., Maksud, A., Foysal, S.I., Chowdhury, R.I., Chowdhury, S.S., and Shahanaz, C. (2017, January 19\u201322). Stetho-phone: Low-cost digital stethoscope for remote personalized healthcare. Proceedings of the 2017 IEEE Global Humanitarian Technology Conference (GHTC), San Jose, CA, USA.","DOI":"10.1109\/GHTC.2017.8239325"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"482","DOI":"10.1109\/LSP.2018.2801341","article-title":"Heart sound extraction from sternal seismocardiographic signal","volume":"25","author":"Choudhary","year":"2018","journal-title":"IEEE Signal Process. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Martinek, R., Kahankova, R., Nedoma, J., Fajkus, M., Nazeran, H., and Nowakova, J. (2017, January 9\u201311). Adaptive signal processing of fetal PCG recorded by interferometric sensor. Proceedings of the Fourth Euro-China Conference on Intelligent Data Analysis and Applications, M\u00e1laga, Spain.","DOI":"10.1007\/978-3-319-68527-4_26"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1038\/s41551-019-0480-6","article-title":"Mechano-acoustic sensing of physiological processes and body motions via a soft wireless device placed at the suprasternal notch","volume":"4","author":"Lee","year":"2020","journal-title":"Nat. Biomed. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1900290","DOI":"10.1002\/advs.201900290","article-title":"A chest-laminated ultrathin and stretchable E-Tattoo for the measurement of electrocardiogram, seismocardiogram, and cardiac time intervals","volume":"6","author":"Ha","year":"2019","journal-title":"Adv. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1038\/s41746-020-0225-7","article-title":"Precision wearable accelerometer contact microphones for longitudinal monitoring of mechano-acoustic cardiopulmonary signals","volume":"3","author":"Gupta","year":"2020","journal-title":"NPJ Digit. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"725716","DOI":"10.3389\/fphys.2021.725716","article-title":"A novel broadband forcecardiography sensor for simultaneous monitoring of respiration, infrasonic cardiac vibrations and heart sounds","volume":"12","author":"Andreozzi","year":"2021","journal-title":"Front. Physiol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Centracchio, J., Andreozzi, E., Esposito, D., Gargiulo, G.D., and Bifulco, P. (2022). Detection of Aortic Valve Opening and Estimation of Pre-Ejection Period in Forcecardiography Recordings. Bioengineering, 9.","DOI":"10.3390\/bioengineering9030089"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Andreozzi, E., Centracchio, J., Esposito, D., and Bifulco, P. (2022). A Comparison of Heart Pulsations Provided by Forcecardiography and Double Integration of Seismocardiogram. Bioengineering, 9.","DOI":"10.3390\/bioengineering9040167"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"015005","DOI":"10.1063\/1.5062619","article-title":"Design of a high SNR electronic heart sound sensor based on a MEMS bionic hydrophone","volume":"9","author":"Li","year":"2019","journal-title":"AIP Adv."},{"key":"ref_20","unstructured":"Everest, F.A., and Pohlmann, K.C. (2022). Master Handbook of Acoustics, McGraw-Hill Education."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3936","DOI":"10.1021\/acsaelm.1c00509","article-title":"Synchronous construction of piezoelectric elements and nanoresistance networks for pressure sensing based on the wheatstone bridge principle","volume":"3","author":"Lv","year":"2021","journal-title":"ACS Appl. Electron. Mater."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41378-020-00227-w","article-title":"Design and implementation of a jellyfish otolith-inspired MEMS vector hydrophone for low-frequency detection","volume":"7","author":"Wang","year":"2021","journal-title":"Microsyst. Nanoeng."},{"key":"ref_23","unstructured":"Zhang, G.J. (2015). The Research of Cilium MEMS Vector Hydrophone. [Ph.D. Dissertation, School of Marine Science and Technology, Acoustics, Northwestern Polytechnical University]."},{"key":"ref_24","unstructured":"Chen, T.-H. (2012). Analysis Method of Heart Sound and ECG Signal Based on Modern Signal Processing Technology, China Machine Press."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1163","DOI":"10.1109\/JSEN.2021.3131001","article-title":"Design and Implementation of Bionic MEMS Electronic Heart Sound Stethoscope","volume":"22","author":"Shi","year":"2021","journal-title":"IEEE Sens. J."},{"key":"ref_26","first-page":"202","article-title":"Research on first heart sound and second heart sound amplitude variability and reversal phenomenon-a new finding in athletic heart study","volume":"29","author":"Wu","year":"2009","journal-title":"J. Med. Biol. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1121\/1.388085","article-title":"Impedance-matching properties of an inhomogeneous matching layer with continuously changing acoustic impedance","volume":"72","author":"Pedersen","year":"1982","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"8316","DOI":"10.1109\/ACCESS.2018.2889437","article-title":"Algorithms for automatic analysis and classification of heart sounds\u2014A systematic review","volume":"7","author":"Dwivedi","year":"2018","journal-title":"IEEE Access"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2344","DOI":"10.3390\/app8122344","article-title":"Classification of heart sound signal using multiple features","volume":"8","author":"Son","year":"2018","journal-title":"Appl. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1080\/03091902.2017.1382584","article-title":"A review of intelligent systems for heart sound signal analysis","volume":"41","author":"Ali","year":"2017","journal-title":"J. Med. Eng. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3861","DOI":"10.1109\/JSEN.2017.2694970","article-title":"Effective heart sound segmentation and murmur classification using empirical wavelet transform and instantaneous phase for electronic stethoscope","volume":"17","author":"Varghees","year":"2017","journal-title":"IEEE Sens. J."},{"key":"ref_32","first-page":"372","article-title":"S1 and S2 heart sound recognition using deep neural networks","volume":"64","author":"Chen","year":"2016","journal-title":"IEEE Trans. Biomed. Eng."}],"container-title":["Micromachines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-666X\/13\/12\/2174\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:36:28Z","timestamp":1760146588000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-666X\/13\/12\/2174"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,8]]},"references-count":32,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["mi13122174"],"URL":"https:\/\/doi.org\/10.3390\/mi13122174","relation":{},"ISSN":["2072-666X"],"issn-type":[{"value":"2072-666X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,8]]}}}