A multi-sensor system may include a catheter that has lumen, is flexible, is made of a polymer, and has a circular cross section that has an outer diameter of no more than 0.5 cm； and one or more sensors that sense multiple characteristics of material flowing within the lumen, including at least two of the following: flow rate, pressure, and composition of the material. A multi-sensor system may include a catheter that has lumen, is flexible, is made of a polymer, and has a circular cross section that has an outer diameter of no more than 0.5 cm； and one or more sensors that sense multiple characteristics of material flowing within the lumen, including at least two of the following: flow rate, pressure, and composition of the material.
