Abstract: A system performs a method for characterizing passage of a patient fluid through a conduit. The method includes quantifying flow of fluidic content through a conduit, where the fluidic content includes a patient fluid, estimating a concentration of a fluid component of the patient fluid in the fluidic content, and characterizing passage of the patient fluid loss through the conduit based on the quantified flow and the concentration of the fluid component. At least one of the quantified flow or the concentration of the fluid component is based on sensor data from a sensor arrangement coupled to the conduit. Other apparatus and methods are also described.