Systematic Investigation of Heart Sound Propagation using Continuous Wave Radar

Oesten M, Abel L, Albrecht NC, Richer R, Langer D, Grießhammer S, Ghanem K, Steigleder T, Ostgathe C, Koelpin A, Eskofier B (2025)

Publication Type: Journal article

Publication year: 2025

Journal

IEEE Journal of Biomedical and Health Informatics Institute of Electrical and Electronics Engineers (IEEE)

DOI: 10.1109/JBHI.2025.3530821

Abstract

Monitoring the propagation of mechanical cardiac signals throughout the body is crucial for assessing cardiovascular health. A common drawback of current gold standard methods for vital sign monitoring is the necessity for continuous skin contact. Radar-based sensing offers a promising alternative by enabling contactless measurement of cardiac activity, including heart sound signals. As previous research has primarily focused on deriving signals from proximal body regions, insights into heart sound propagation to peripheral areas are lacking. To address this, we systematically investigated whether radar-based heart sound detection and propagation measurement is feasible across the whole body. We recorded heart sounds in N=22 participants sequentially at eleven locations using a custom-built continuous-wave radar system and phonocardiogram as heart sound gold standard. Additionally, an electrocardiogram was acquired as reference for overall heart activity. After synchronization and preprocessing, we manually segmented the heart sounds and extracted temporal characteristics from ensemble-averaged signals. Our findings show that heart sounds can be detected across the entire body with the radar-based as well as the gold standard system. Furthermore, the heart sounds’ temporal characteristics vary between measurement locations. As the distance to the heart increases, we observed significantly increased propagation time intervals. This finding is consistent across both systems, exhibiting a strong agreement for the first heart sound (r = 0.73, p < 0.001) and a moderate agreement for the second heart sound (r = 0.56, p < 0.001). In conclusion, our work is the first to demonstrate that radar-based systems are feasible for contactless evaluation of heart sound propagation, offering new possibilities for research and health monitoring.

Authors with CRIS profile

Marie Oesten Department of Palliative Medicine Luca Abel Machine Learning and Data Analytics Lab Nils Christian Albrecht
Robert Richer Machine Learning and Data Analytics Lab Stefan Grießhammer Department of Palliative Medicine Tobias Steigleder Department of Palliative Medicine Christoph Ostgathe Professur für Palliativmedizin Björn Eskofier Machine Learning and Data Analytics Lab

Additional Organisation(s)

Sonderforschungsbereich 1483/1 - Empathokinästhetische Sensorik - Sensortechniken und Datenanalyseverfahren zur empathokinästhetischen Modellbildung und Zustandsbestimmung (SFB EmpkinS)

Related research project(s)

Empathokinästhetische Messung und Bewegungsmustererkennung als Biomarker für Gesundheitszustand (SFB 1483 EmpkinS D05) Empatho-Kinaesthetic Sensor Technology (SFB 1483 EmpkinS) July 1, 2021 - June 30, 2025 Empatho-Kinaesthetic Sensor Technology (SFB 1483 EmpkinS) July 1, 2021 - June 30, 2025

Involved external institutions

Centre de Developpement des Technologies Avancées (CDTA) DZ Algeria (DZ) Technische Universität Hamburg-Harburg (TUHH) DE Germany (DE)

How to cite

APA:

Oesten, M., Abel, L., Albrecht, N.C., Richer, R., Langer, D., Grießhammer, S.,... Eskofier, B. (2025). Systematic Investigation of Heart Sound Propagation using Continuous Wave Radar. IEEE Journal of Biomedical and Health Informatics. https://doi.org/10.1109/JBHI.2025.3530821

MLA:

Oesten, Marie, et al. "Systematic Investigation of Heart Sound Propagation using Continuous Wave Radar." IEEE Journal of Biomedical and Health Informatics (2025).

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