Method of removing blood from an extracorporeal blood circuit, treatment apparatus, and tube system

A treatment apparatus comprising:

• at least one extracorporeal blood circuit comprising:
• an arterial conduit portion having a conduit interior and an arterial patient tube clamp;
• a venous conduit portion having a conduit interior and a venous patient tube clamp;
• an arterial needle;
• and
• a venous needle;
• at least one conveyor comprising a blood pump arranged at or in the extracorporeal blood circuit and adapted to convey blood within the extracorporeal blood circuit;
• at least one second pump adapted to pump at least one liquid into the extracorporeal blood circuit;
• and
• at least one controller configured to remove blood, via the at least one liquid pumped into the extracorporeal blood circuit while a patient is connected to the treatment apparatus, from both the arterial conduit portion and from the venous conduit portion of the extracorporeal blood circuit and towards the arterial needle and the venous needle, respectively,
• wherein, during the removal of blood both from the arterial conduit portion and from the venous conduit portion, both the arterial patient tube clamp and the venous patient tube clamp are in an opened state, and
• wherein a predetermined quantity of the at least one liquid is introduced into the extracorporeal blood circuit by operating the second pump, and
• wherein the predetermined quantity of the at least one liquid may optionally be deposited and/or input in the at least one controller.