Embodiments of the present disclosure are configured to assess the severity of a blockage in a vessel and, in particular, a stenosis in a blood vessel. In some particular embodiments, the devices, systems, and methods of the present disclosure are configured to assess the severity of a stenosis in the coronary arteries by monitoring fluid flow. In some embodiments, the devices, systems, and methods of the present disclosure receive analog sensor data that includes fluid flow data and digitizes the analog sensor data according to a quadrature sampling rate. A weighted accumulator performs a baseband conversion on the digitized sensor data and may perform other signal processing steps. The processed data is then provided for use in any one of a number of diagnostic assessments.
