Clinical testing of software and medical devices based on photople-thysmography (PPG) sensors: a scoping review

Photoplethysmography (PPG)-based devices are increasingly used for the continuous assessment of physiological parameters in daily life, offering significant value for preventive healthcare and the management of chronic diseases. Therefore, careful consideration must be given to the design of clinical trials that reflect the real-world use of PPG-based wearables. This scoping review maps clinical trial designs, populations, testing environments, and validation outcomes in PPG technologies. A systematic search was conducted across PubMed/MEDLINE, Scopus, IEEE Xplore, Embase, Web of Science, the Cochrane Library, ACM Digital Library, CINAHL, LILACS, and grey literature for data published between 1 January 2020 and 27 October 2025. This scoping review characterized the clinical evidence landscape for PPG-based devices across 120 studies. Studies were screened, and data were extracted using a structured framework that addressed clinical settings, study designs, population characteristics, anatomical locations, safety reporting, and methodological quality. PPG wearables offer opportunities for early cardiovascular screening and widespread clinical adoption. Currently, the evidence base demonstrates broad clinical ambition but is constrained by limited design rigor, small sample sizes, and inadequate reporting of population diversity. International consortia are expected to harmonize PPG validation frameworks within 5 years, establishing unified benchmarks across expanding clinical applications.