Clinical Research Directory

Smartphone Application for Automated Measurement of Capillary Refill Time (CRT)

This prospective, monocenter observational study aims to validate a smartphone application (CRTApp) that automatically measures capillary refill time (CRT) from a short video of a standardized finger compression. Sixty adult intensive care unit (ICU) patients will undergo a CRT measurement recorded with a professional Android smartphone. Clinical CRT will be determined from the video by three blinded observers (reference = median of the three measurements). The application will analyze the same video locally to provide an automated CRT measurement. Agreement between automated and clinical reference CRT will be assessed, and predefined subgroup analyses will explore performance across skin tone, ambient lighting, smartphone characteristics, and severity of peripheral hypoperfusion.