Patent ID: 6827698
Filing Date: 2004-12-07
Classification: A61M

Abstract:
A method of operating a blood treatment machine for determining a blood flow QF in a vascular access of an extracorporeal circulation during an extracorporeal blood treatment, wherein blood entering a blood treatment unit of the blood treatment machine through an arterial connection of an arterial branch is in fluid connection with the vascular access, and is returned through a venous connection of a venous branch in fluid connection with the vascular access, the method comprising the steps of:measuring at least one pair of pressures selected from the group consisting of part, part comp and pven, pven comp, wherein part, part comp are, respectively, the arterial branch pressure while the vascular access is open and blood flows through said vascular access between the arterial and venous connections, and while the vascular access is interrupted and no blood flows through the vascular access between the arterial and venous connections, while a blood flow QB in the extracorporeal circulation is varied, and wherein pven, pven comp are, respectively, the venous branch pressure while the vascular access is open and blood flows through said vascular access between the arterial and venous connections, and while the vascular access is interrupted and no blood flows through the vascular access between the arterial and venous connections, while the blood flow QB in the extracorporeal circulation is varied; and calculating the blood flow QF in the open vascular access between the arterial and venous connections from the measured values of the at least one pair of pressures selected from the group consisting of part, part comp and pven, pven comp.