An infusion system (1) comprising one or more infusion sources (e.g. pumps and/or reservoirs (2, 3, 4, 9, 10)) and hose lines (5, 11) leading to a patient access (7, 12) for the infusion of a liquid, has a signal generator (A/S), which introduces a pressure signal or an acoustic signal into the liquid, and a sensor (S), which is arranged spaced apart from the signal generator in the infusion system, and an evaluation circuit, which is operatively connected to the sensor in such a way that a sensor signal output by the sensor produces an input signal of the evaluation circuit, said evaluation circuit being operatively connected to a display in such a way that information based on the sensor signals, about the infusion system, such as the flow rate of the liquid, can be displayed. The invention further discloses a method for integrity monitoring of such an infusion system.