Capillary refill time (CRT) is a non-invasive marker of patient blood flow that is significantly impaired during sepsis or hemodynamic shock. Our solution (PeriFRL) which utilizes reflective light to provide skin tone agnostic circulatory function monitoring, fits within the existing clinical workflows. It is affordable and can be deployed across a variety of settings, from EDs, ICUs and trauma, to low-resourced birthing centers, even to EMS.