An Infusion device (1) for administering a medical fluid to a patient (P) comprises a pumping mechanism (11) for pumping a medical fluid from a fluid container (20) through a delivery line (3) towards a patient (P) at a set flow rate, a sensor device (14) for measuring a force on the pumping mechanism (11) or the delivery line (3), and a processor device (15) for deriving, from the force measured by the sensor device (14), a pressure value indicative of the pressure in the delivery line (3), wherein the processor device (15) is constituted to compare the pressure value to a threshold value for determining whether a occlusion (O) in the delivery line (3) is present. Herein, a storage device (16) stores a compliance value associated with the pumping mechanism (11) and/or the delivery line (3), wherein the processor device (15) is constituted to compute, from the stored compliance value, the flow rate and the threshold value, an estimate of a duration (T) between the time (t0) of an occurrence of an occlusion (O) in the delivery line (3) and the time (t1) at which the pressure value exceeds the threshold value (Pthres). In this way an infusion device for administering a medical fluid to a patient is provided which may facilitate the programming of a threshold value for the occlusion detection and may provide a higher level of confidence to a user for the occlusion detection.
