A device for purifying blood includes an extracorporeal blood circulation loop, flow rate control elements to manage the blood circulation in the extracorporeal blood circulation loop, blood purification elements configured on the extracorporeal blood circulation loop, citrate injection elements for injecting a solution including citrate into the extracorporeal blood circulation loop, and a control unit configured to control the citrate injection elements and the flow rate control elements. The control unit is further configured to require, at determined time intervals of a blood purification treatment used by the device, the entry of at least one representative value of the status of the device and/or of the patient. The control unit then verifies the adequacy of the representative value with pre-established rules stored in the control unit and controls the citrate injection elements and/or the flow rate control elements in accordance with the result of the verification and the pre-established rules.
