Method and apparatus for priming an extracorporeal blood circuit

An extracorporeal blood treatment apparatus comprising:

• a casing internally defining a containing space;
• a treatment fluid circuit which is arranged internally of the containing space, the treatment fluid circuit comprising:
• a fresh treatment fluid supply line which is configured to connect a treatment fluid source with a fluid chamber of a blood treatment device of a type having a semipermeable membrane;
• and
• a used treatment fluid discharge line which is configured to connect the fluid chamber with a drain;
• a waste priming fluid discharge apparatus comprising:
• a first priming fluid discharge port which comprises a respective first opening obtained on said casing;
• a first priming fluid discharge line which connects the first priming fluid discharge port with the used treatment fluid discharge line, the first priming fluid discharge line having at least a first tract thereof arranged internally of the containing space, wherein the first priming fluid discharge line includes a first check valve which is configured to block flow towards the first priming fluid discharge port;
• a second priming fluid discharge port which comprises a respective second opening obtained on said casing;
• and
• a second priming fluid discharge line which connects the second priming fluid discharge port with the used treatment fluid waste line, the second priming fluid discharge line having at least a second tract arranged internally of the containing space, the second tract being distinct from the first tract, wherein the second priming fluid discharge line includes a second check valve which is configured to block flow towards the second priming fluid discharge port;
• and
• the apparatus being further configured to hold an extracorporeal blood circuit comprising:
• a blood chamber of said blood treatment device in which the semipermeable membrane separates the blood chamber from the fluid chamber;
• an arterial blood line having a first arterial end connected to the blood chamber and a second arterial end;
• a venous blood line having a first venous end connected to the blood chamber and a second venous end;
• wherein the first priming fluid discharge port is configured to removably receive one of said second arterial end and said second venous end, and wherein the second priming fluid discharge port is configured to removably receive the other of said second arterial end and said second venous end.