Wearable Health Monitoring from Sensors to Clinical Intelligence: A Critical Review of Sensing Technologies, Signal Processing, IoT Architectures and Clinical Translation 2020 to 2026

Health-monitoring systems are now used outside the clinic. Technological advances have allowed us to capture more physiological measures and use them elsewhere. The possibilities have been broadened with advances in ECG, photoplethysmography (PPG), temperature, inertial measurement, embedded processing, and wireless communication. However, the clinical utility and applications of wearable devices remain limited due to a lack of reliability, energy, interoperability, demographics, cybersecurity, and integration into clinical practice. In this paper, studies were searched in the database of Scopus, Web of Science, PubMed/MEDLINE, IEEE Xplore, SpringerLink, and Google Scholar in September 2026. After screening 123 records, 22 studies have been identified to fit into the scope of study of this paper. Data were collected in areas of sensing, analytics, system architecture, and clinical translation. According to the existing data, these studies have reported a range of sensor, with varying skin contact, perfusion, or environment. Although there has been no significant improvement in signal quality, there appears to be little support for a clinically applicable device. The primary contribution of this review is a holistic design perspective that includes multimodal monitoring, evaluation of signal quality, adaptive edge analytics, energy-aware communication, privacy and interoperability, and clinically useful decision support. Future studies will focus on independent and longitudinal testing among a variety of populations and realistic activity conditions and evaluate clinical utility technical performance.