Method and device for monitoring a vascular access and extracorporeal blood treatment device comprising a device for monitoring vascular access

A method of monitoring a vascular access during extra-corporeal blood treatment in which blood flows from the vascular access via an arterial segment of an extra-corporeal blood circuit into a blood-treating element, and from the blood-treating element via a venous segment back into the vascular access, comprising the steps of:

• measuring the pressure in the venous and arterial segments of the extra-corporeal blood circuit;
• determining a test function that defines interference affecting the measured arterial and venous pressures;
• determining a pressure differential that is freed from interference from the measured venous and arterial pressures;
• and
• analyzing the pressure differential that has been freed from interference to detect a faulty vascular access.

An arrangement for monitoring a vascular access for an extra-corporeal blood-treating apparatus for performing extra-corporeal blood treatment in which blood flows from the vascular access via an arterial segment of an extra-corporeal blood circuit into a blood-treating element, and from the blood-treating element via a venous segment back into the vascular access, said arrangement comprising:

• a measuring unit for measuring a pressure in the venous and arterial segments of the extra-corporeal blood circuit;
• and
• an analyzing unit for analyzing the measured venous and arterial pressures to enable a faulty vascular access to be found, wherein the analyzing unit comprises:
• a means for determining a test function that defines interference affecting the measured arterial and venous pressures;
• and
• the analyzing unit is designed such that a pressure differential that is freed from interference is determined from the measured venous and arterial pressures using the test function that defines interference affecting the arterial and venous pressures, and the pressure differential that is freed from interference is analyzed to allow a faulty access to be detected.

An apparatus for extra-corporeal blood treatment comprising:

• a vascular access;
• an arterial segment;
• a venous segment;
• a blood-treating element;
• and
• an arrangement for monitoring the vascular access comprising:
• a measuring unit for measuring a pressure in the venous and arterial segments of the extra-corporeal blood circuit;
• and
• an analyzing unit for analyzing the measured venous and arterial pressures to enable a faulty vascular access to be found, wherein the analyzing unit comprises:
• a means for determining a test function that defines interference affecting the measured arterial and venous pressures, and
• wherein said analyzing unit is designed such that a pressure differential that is freed from interference is determined from the measured venous and arterial pressures using the test function that defines interference affecting the arterial and venous pressures, and the pressure differential that is freed from interference is analyzed to allow a faulty access to be detected.