An infusion device (3) for administering a medical fluid to a patient, comprises a housing (30) and a receptacle (300) arranged on the housing (30) for receiving a syringe (4), the syringe (4) having a barrel (41 ) for containing a medical fluid and a plunger (42) movable relative to the barrel (41 ) for delivering the medical fluid out of the barrel (41 ). A pusher device (32) is movable relative to the housing (30) for acting onto the plunger (42) for moving the plunger (42) relative to the barrel (41 ), and a drive mechanism (38) drives the pusher device (32). A coupling mechanism (36, 37) is operative to couple the plunger (42) to the pusher device (32) or to couple the pusher device (32) to the drive mechanism (38), and an actuation mechanism arranged on the pusher device (32) comprises an actuation element (33) for actuating the coupling mechanism (36, 37) between a coupling state and an uncoupling state. Herein, the actuation mechanism comprises a first threaded element (34) rotatable about a rotational axis (342) and a second threaded element (331 ) movable along the first threaded element (34), the second threaded element (331 ) being in threaded engagement with the first threaded element (34) such that the first threaded element (34) is rotated when the second threaded element (331 ) is moved along the first threaded element (34), wherein the actuation element (33) is actuatable to move the second threaded element (331 ) along the first threaded element (34), the first threaded element (34) being operatively connected to the coupling mechanism (36, 37). In this way an infusion device is provided which in an easy and comfortable manner allows a user to actuate a coupling mechanism, in particular for installing a syringe on a receptacle of the infusion device.L'invention concerne un dispositif de perfusion (3) pour administrer un fluide médical à un patient, comprenant un boîtier (30) et un réceptacle (300) disposé sur le boîtier (30) pour recevoir une serin
