Advancements in wearable heart sounds devices for the monitoring of cardiovascular diseases

Cardiovascular diseases are a major global cause of mortality, highlighting the need for intelligent diagnostic tools for early detection and management. This demand has driven the development of wearable and flexible technologies for continuous, noninvasive heart sound (HS) monitoring, improving assessments of heart activity. Conventional stethoscopes are limited by their inflexible and bulky design, which restricts their applications. Recent advancements in mechanoacoustic sensors have led to soft, flexible, and wearable designs. This article reviews the latest scientific and technological progress in flexible and wearable HS sensors, covering sensor types, materials, design principles, denoising techniques, and clinical applications. The potential for ongoing, remote, and personalized monitoring promises improved patient outcomes and timely diagnoses. The article also addresses current challenges and future prospects, suggesting methods to enhance HS sensing technologies for real-time applications.

Heart anatomy and graphical representation of HSs. (A) Description of human heart parts. (B) Representation of a complete cardiac cycle, i.e., diastole and systole phase. (C) Pattern of S1, S2, S3, and S4 (Reproduced under the terms of CC-BY-NC-ND license: Copyright 2022, Elsevier.10). HS, heart sound.