Some embodiments relate to a device, method, and/or computer-readable medium storing processor-executable process steps for processing a photoplethysmographic (“PPG”) signal in a monitoring device that monitors a property of blood flow. In some embodiments, the processing includes obtaining a first digital signal representing a detected light signal having a non-pulsatile (e.g., DC) component and a pulsatile component (e.g., AC). An offset control signal is generated from an estimation of the non-pulsatile component and a second digital signal is generated after subtracting the offset control signal from the detected light signal and applying a gain to the subtracted signal. A reconstructed signal is generated that is calculated from the gain and one or more of (i) the first digital signal, and (ii) the second digital signal and the offset control signal.