{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T09:29:45Z","timestamp":1790760585433,"version":"4.1.0"},"reference-count":36,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,27]],"date-time":"2025-05-27T00:00:00Z","timestamp":1748304000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Fonds Erasme","award":["FC 04370"],"award-info":[{"award-number":["FC 04370"]}]},{"name":"Fonds Erasme","award":["PEA 4000110826"],"award-info":[{"award-number":["PEA 4000110826"]}]},{"name":"Fonds de la Recherche Scientifique (Mandat Aspirant F.R.S.\u2014FNRS)","award":["FC 04370"],"award-info":[{"award-number":["FC 04370"]}]},{"name":"Fonds de la Recherche Scientifique (Mandat Aspirant F.R.S.\u2014FNRS)","award":["PEA 4000110826"],"award-info":[{"award-number":["PEA 4000110826"]}]},{"name":"PRODEX","award":["FC 04370"],"award-info":[{"award-number":["FC 04370"]}]},{"name":"PRODEX","award":["PEA 4000110826"],"award-info":[{"award-number":["PEA 4000110826"]}]},{"name":"Fonds pour la chirurgie cardiaque","award":["FC 04370"],"award-info":[{"award-number":["FC 04370"]}]},{"name":"Fonds pour la chirurgie cardiaque","award":["PEA 4000110826"],"award-info":[{"award-number":["PEA 4000110826"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Severe aortic valve diseases (AVD) cause changes in heart sounds, making phonocardiogram (PCG) analyses challenging. This study presents a novel method for segmenting heart sounds without relying on an electrocardiogram (ECG), specifically targeting patients with severe AVD. Our algorithm enhances traditional Hidden Semi-Markov Models by incorporating signal envelope calculations and statistical tests to improve the detection of the first and second heart sounds (S1 and S2). We evaluated the method on the PhysioNet\/CinC 2016 Challenge dataset and a newly acquired AVD-specific dataset. The method was tested on a total of 27,400 cardiac cycles. The proposed approach outperformed the existing methods, achieving a higher sensitivity and positive predictive value for S2, especially in the presence of severe heart murmurs. Notably, in patients with severe aortic stenosis, our proposed ECG-free method improved S2 sensitivity from 41% to 70%.<\/jats:p>","DOI":"10.3390\/s25113360","type":"journal-article","created":{"date-parts":[[2025,5,27]],"date-time":"2025-05-27T05:52:52Z","timestamp":1748325172000},"page":"3360","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["A Novel Method for ECG-Free Heart Sound Segmentation in Patients with Severe Aortic Valve Disease"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-8586-7513","authenticated-orcid":false,"given":"Elza","family":"Abdessater","sequence":"first","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6336-167X","authenticated-orcid":false,"given":"Paniz","family":"Balali","sequence":"additional","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"},{"name":"Laboratory of Image Synthesis and Analysis (LISA), Universit\u00e9 libre de Bruxelles, 1050 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jimmy","family":"Pawlowski","sequence":"additional","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7946-075X","authenticated-orcid":false,"given":"J\u00e9r\u00e9my","family":"Rabineau","sequence":"additional","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"},{"name":"Research Unit in Cardio-Respiratory Physiology, Exercise & Nutrition, Faculty of Human Movement Sciences, Universit\u00e9 libre de Bruxelles, 1070 Brussels, Belgium"},{"name":"Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6098-7463","authenticated-orcid":false,"given":"Cyril","family":"Tordeur","sequence":"additional","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"},{"name":"Research Unit in Cardio-Respiratory Physiology, Exercise & Nutrition, Faculty of Human Movement Sciences, Universit\u00e9 libre de Bruxelles, 1070 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vitalie","family":"Faoro","sequence":"additional","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"},{"name":"Research Unit in Cardio-Respiratory Physiology, Exercise & Nutrition, Faculty of Human Movement Sciences, Universit\u00e9 libre de Bruxelles, 1070 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5693-1045","authenticated-orcid":false,"given":"Philippe","family":"van de Borne","sequence":"additional","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amin","family":"Hossein","sequence":"additional","affiliation":[{"name":"Laboratory of Physics and Physiology, Department of Cardiology, H\u00f4pital Erasme, H\u00f4pital Universitaire de Bruxelles, 1070 Brussels, Belgium"},{"name":"Research Unit in Cardio-Respiratory Physiology, Exercise & Nutrition, Faculty of Human Movement Sciences, Universit\u00e9 libre de Bruxelles, 1070 Brussels, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"716","DOI":"10.1093\/eurheartj\/ehab892","article-title":"European Society of Cardiology: Cardiovascular disease statistics 2021","volume":"43","author":"Timmis","year":"2022","journal-title":"Eur. Heart J."},{"key":"ref_2","first-page":"217","article-title":"Transcatheter Aortic-Valve Replacement for Asymptomatic Severe Aortic Stenosis","volume":"392","author":"Schwartz","year":"2024","journal-title":"N. Engl. J. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1093\/ehjqcco\/qcad026","article-title":"A worldwide perspective on the temporal burden and impact of calcific aortic valve disease","volume":"9","author":"Iung","year":"2023","journal-title":"Eur. Heart J. Qual. Care Clin. Outcomes"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.ahj.2025.03.006","article-title":"Cardiac auscultation skills among medical trainees","volume":"286","author":"Zhang","year":"2025","journal-title":"Am. Heart J."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"5584","DOI":"10.21037\/jtd.2018.09.02","article-title":"Patient screening for early detection of aortic stenosis (AS)\u2014Review of current practice and future perspectives","volume":"10","author":"Thoenes","year":"2018","journal-title":"J. Thorac. Dis."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Karelas, D., Tatsis, E., Oikonomidis, D., and Papadopoulos, C.H. (2025). Diagnostic Challenges in the Management of Aortic Valve Stenosis and the Role of Imaging: A Narrative Review. J. Clin. Med., 14.","DOI":"10.3390\/jcm14041231"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Zhang, W.L., Huang, Q.J., Yu, J.W., Zhu, Z.B., and Zhang, R.Y. (2023). Feasibility of remote screening for high risk valve disease using a new wearable cardiac monitoring patch with synchronized phonocardiogram and electrocardiogram in communities. Eur. Heart J., 44.","DOI":"10.1093\/eurheartj\/ehad655.2977"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6063","DOI":"10.1007\/s10462-021-09969-z","article-title":"Detection of heart valve disorders from PCG signals using TQWT, FA-MVEMD, Shannon energy envelope and deterministic learning","volume":"54","author":"Zeng","year":"2021","journal-title":"Artif. Intell. Rev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/j.bspc.2012.11.008","article-title":"A robust heart sounds segmentation module based on S-transform","volume":"8","author":"Moukadem","year":"2013","journal-title":"Biomed. Signal Process. Control"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2181","DOI":"10.1088\/0967-3334\/37\/12\/2181","article-title":"An open access database for the evaluation of heart sound algorithms","volume":"37","author":"Liu","year":"2016","journal-title":"Physiol. Meas."},{"key":"ref_11","unstructured":"Dornbush, S., and Turnquest, A.E. (2024, November 05). Physiology, Heart Sounds, StatPearls [Internet], Available online: http:\/\/www.ncbi.nlm.nih.gov\/books\/NBK541010\/."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1007\/s10439-012-0645-x","article-title":"Detection and boundary identification of phonocardiogram sounds using an expert frequency-energy based metric","volume":"41","author":"Naseri","year":"2013","journal-title":"Ann. Biomed. Eng."},{"key":"ref_13","first-page":"822","article-title":"Logistic Regression-HSMM-Based Heart Sound Segmentation","volume":"63","author":"Springer","year":"2016","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Shukla, S., Singh, S.K., and Mitra, D. (2020). An efficient heart sound segmentation approach using kurtosis and zero frequency filter features. Biomed. Signal Process. Control, 57.","DOI":"10.1016\/j.bspc.2019.101762"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1007\/s40846-017-0320-7","article-title":"A Robust Algorithm for Segmentation of Phonocardiography Signal Using Tunable Quality Wavelet Transform","volume":"38","author":"Jain","year":"2018","journal-title":"J. Med. Biol. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Xu, X., Geng, X., Gao, Z., Yang, H., Dai, Z., and Zhang, H. (2023). Optimal Heart Sound Segmentation Algorithm Based on K-Mean Clustering and Wavelet Transform. Appl. Sci., 13.","DOI":"10.3390\/app13021170"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"7747","DOI":"10.1109\/ACCESS.2024.3351570","article-title":"A Noise-Robust Heart Sound Segmentation Algorithm Based on Shannon Energy","volume":"12","author":"Arjoune","year":"2024","journal-title":"IEEE Access"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"117203","DOI":"10.1109\/ACCESS.2024.3432309","article-title":"A Comprehensive Overview of Heart Sound Analysis Using Machine Learning Methods","volume":"12","author":"Hamza","year":"2024","journal-title":"IEEE Access"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"830","DOI":"10.1016\/0002-9149(78)90721-X","article-title":"Determinants of the amplitude of the aortic component of the second heart sound in aortic stenosis","volume":"41","author":"Sabbah","year":"1978","journal-title":"Am. J. Cardiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1109\/TBME.1985.325532","article-title":"A real-time QRS detection algorithm","volume":"32","author":"Pan","year":"1985","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"671","DOI":"10.21105\/joss.00671","article-title":"BioSigKit: A Matlab Toolbox and Interface for Analysis of BioSignals","volume":"3","author":"Sedghamiz","year":"2018","journal-title":"J. Open Source Softw."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Keyzer, E., Hossein, A., Rabineau, J., Morissens, M., Almorad, A., and van de Borne, P. (2023). Non-invasive cardiac kinetic energy distribution: A new marker of heart failure with impaired ejection fraction (KINO-HF). Front. Cardiovasc. Med., 10.","DOI":"10.3389\/fcvm.2023.1096859"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3446","DOI":"10.1002\/ehf2.14477","article-title":"The kinocardiograph for assessment of fluid status in patients with acute decompensated heart failure","volume":"10","author":"Herkert","year":"2023","journal-title":"ESC Heart Fail."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1023\/B:VISI.0000013087.49260.fb","article-title":"Robust Real-Time Face Detection","volume":"57","author":"Viola","year":"2004","journal-title":"Int. J. Comput. Vis."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1016\/j.cmpb.2009.09.008","article-title":"The moment segmentation analysis of heart sound pattern","volume":"98","author":"Yan","year":"2010","journal-title":"Comput. Methods Programs Biomed."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Pretorius, E., Cronje, M.L., and Strydom, O. (September, January 31). Development of a pediatric cardiac computer aided auscultation decision support system. Proceedings of the 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology, Buenos Aires, Argentina.","DOI":"10.1109\/IEMBS.2010.5627633"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Wang, P., Kim, Y., Ling, L., and Soh, C. (2006, January 17\u201318). First heart sound detection for phonocardiogram segmentation. Proceedings of the 2005 IEEE Engineering in Medicine and Biology 27th Annual Conference, Shanghai, China.","DOI":"10.1109\/IEMBS.2005.1615733"},{"key":"ref_28","unstructured":"Liang, H., Lukkarinen, S., and Hartimo, I. (1997, January 7\u201310). Heart sound segmentation algorithm based on heart sound envelogram. Proceedings of the Computers in Cardiology 1997, Lund, Sweden."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1016\/j.bspc.2014.05.002","article-title":"A novel heart sound activity detection framework for automated heart sound analysis","volume":"13","author":"Varghees","year":"2014","journal-title":"Biomed. Signal Process. Control"},{"key":"ref_30","first-page":"524","article-title":"2021 ESC\/EACTS Guidelines for the management of valvular heart disease: Developed by the Task Force for the management of valvular heart disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)","volume":"75","author":"Vahanian","year":"2022","journal-title":"Rev. Esp. Cardiol. (Engl. Ed.)"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"292","DOI":"10.7326\/0003-4819-106-2-292","article-title":"Valvular aortic stenosis. A clinical and hemodynamic profile of patients","volume":"106","author":"Lombard","year":"1987","journal-title":"Ann. Intern. Med."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1138","DOI":"10.1109\/JBHI.2013.2294399","article-title":"Efficient Heart Sound Segmentation and Extraction Using Ensemble Empirical Mode Decomposition and Kurtosis Features","volume":"18","author":"Papadaniil","year":"2014","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2524","DOI":"10.1109\/JBHI.2021.3137048","article-title":"The CirCor DigiScope Dataset: From Murmur Detection to Murmur Classification","volume":"26","author":"Oliveira","year":"2022","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2435","DOI":"10.1109\/JBHI.2019.2894222","article-title":"Deep Convolutional Neural Networks for Heart Sound Segmentation","volume":"23","author":"Renna","year":"2019","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"e13535","DOI":"10.1111\/exsy.13535","article-title":"Artificial intelligence for heart sound classification: A review","volume":"41","author":"Chen","year":"2024","journal-title":"Expert Syst."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Costa, M.D., Davis, R.B., and Goldberger, A.L. (2017). Heart Rate Fragmentation: A New Approach to the Analysis of Cardiac Interbeat Interval Dynamics. Front. Physiol., 8.","DOI":"10.3389\/fphys.2017.00255"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/11\/3360\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:41:08Z","timestamp":1760031668000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/11\/3360"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,5,27]]},"references-count":36,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["s25113360"],"URL":"https:\/\/doi.org\/10.3390\/s25113360","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5,27]]}}}