Method of initialising an apparatus for blood treatment in the single-needle mode and apparatus for blood treatment in the single-needle mode

摘要

An apparatus and method for blood treatment for the single-needle mode, the apparatus having an extra-corporeal blood circuit with a blood infeed line running to the inlet and a blood return line leading away from the outlet, of a blood treating unit, includes in the blood return line a device, e.g., container, for amassing blood, which is in flow-permitting connection for gas transfer with a device, e.g., container, for storing gas. A pressure is calculated and set in the device for storing gas before the arterial and venous phases are started, with two constraints. First, the pressure should be sufficiently low to ensure both no infusion of air into the patient and also regulated flow of blood into the patient even at opposing pressures lower than ambient pressure. Second, the pressure should be sufficiently high to expel blood from the device for amassing blood into the device for storing gas.

主权项

1. A method of using a blood-treatment apparatus for single-needle mode, comprising:
during an arterial phase, making a connection between a device for amassing blood which encloses a sealed-off volume of space, and a device for storing gas which encloses a sealed-off volume of space, the device for amassing blood and the device for storing gas forming, together with a device for making a connection between the device for amassing blood and the device for storing gas, a sealed volume, which no gas can enter and from which no gas can exit, and feeding blood to the device for amassing blood, gas which is expelled from the sealed-off volume of space in the device for amassing blood being transferred to the device for storing gas, thus causing a pressure to be generated in the device for storing gas; and during a venous phase, making a connection between the device for storing gas and the device for amassing blood, the device for amassing blood and the device for storing gas forming, together with the device for making a connection between the device for amassing blood and the device for storing gas, a sealed volume, which no gas can enter and from which no gas can exit, and gas which has been stored in the device for storing gas is transferred to the device for amassing blood, thus expelling the blood which is contained in the sealed-off volume of space in the device for amassing blood, an ongoing changeover being made between the arterial phase in which the device for amassing blood is filled with blood to an upper changeover point and the venous phase in which the device for amassing blood is emptied to a lower changeover point, thus causing blood to be fed to the extra-corporeal blood circuit in the arterial phase and blood to be extracted from the extra-corporeal blood circuit in the venous phase; wherein, for initialisation of successive arterial and venous phases, a pressure pAir reservoir max. which is to be set in the device for storing gas is calculated and, for the initialisation, the pressure pAir reservoir max. previously calculated is set in the device for storing gas before the arterial and venous phases are started.