Method and device for monitoring extracorporeal blood flow

A method for monitoring an extracorporeal blood flow during an extracorporeal blood treatment using an extracorporeal blood treatment device in which blood from a patient is conveyed with a blood pump from an arterial patient connection via an arterial branch of the extracorporeal blood flow into a blood treatment unit and out of the blood treatment unit via a venous branch of the extracorporeal blood flow to a venous patient connection, a venous cut-off unit provided in the venous branch upstream of the venous patient connection, the method comprising:

• monitoring at least one of an arterial access or a venous access with a first method and a second method, wherein the first method and the second method check for a presence of at least one criterion that is characteristic of a faulty vascular access, wherein the at least one criterion checked by the first method and the at least one criterion checked by the second method are different;
• establishing, based on the least one criterion checked by the first method, that the vascular access is faulty;
• stopping the blood pump and keeping the venous cut-off unit open;
• checking, while the blood pump is stopped, for the presence of the least one criterion checked by the second method;
• and
• one of:
• closing the venous cut-off unit if the at least one criterion checked by the second method is present;
• and
• restarting the blood pump if the at least one criterion checked by the second method is not present.

An extracorporeal blood treatment device having an extracorporeal blood flow, the device comprising:

• a blood treatment unit;
• an arterial branch leading to the blood treatment unit;
• an arterial patient connection;
• a venous branch leading from the blood treatment unit;
• a venous patient connection;
• a venous cut-off unit provided upstream of the venous patient connection;
• a blood pump configured to convey blood in the extracorporeal blood flow;
• a central control and computing unit configured to control the blood pump and the venous cut-off unit;
• and
• a device for monitoring the extracorporeal blood flow;
• wherein the central control and computing unit is configured to:
• stop the blood pump after receipt of a control signal from the monitoring device to stop the blood pump;
• start the blood pump after receipt of a control signal from the monitoring device to start the blood pump;
• and
• close the venous cut-off unit after receipt of a control signal to close the venous cut-off unit.