IoT-Enabled Digital Stethoscopes for Remote Cardio-Respiratory Monitoring: A Review of Sensing, Signal Processing, Wireless Communication, and Telemedicine Integration

Abstract

The advances in Internet of Things (IoT), embedded systems, wireless connections, and digital health technologies have provided new chances for monitoring and treatment of patients from distance. Digital stethoscopes play a significant role in this domain, which allow the recording and transmitting of physiological sounds in an electronic form. This review covers the underlying aspects of IoT-connected digital stethoscopes and their applications in telemedicine and cardio-respiratory monitoring. This review analyzes the main sensing technologies and hardware used in the devices, including MEMS microphones, amplification and signal conditioning circuits, microcontrollers, temperature regulating devices, wireless devices, cloud platforms, and mobile applications. Special attention is paid to signals collection and treatment, transmission, cloud storing, and multi-parameter monitoring. Furthermore, the review presents the evidence of the fast-growing use of artificial intelligence for analysis and classification of physiological sounds. Existing technologies demonstrate the opportunities of using connected digital stethoscopes in terms of their portability and records, but still need to address the issues of environmental noise, signal quality, communication delay, battery life, network dependency, data security, privacy, and validation in clinical practice. The study highlights the limitations and mentions directions for future research towards smart, economical, portable, trustworthy, and clinically valuable digital stethoscopes in the domain of telemedicine, rural health care, home monitoring, and emergency medicine.