Method and device for monitoring the introduction of substitution fluids upstream of downstream of a dialyzer of filter

A method for checking the supply of substitution fluid for an extracorporeal blood treatment apparatus that includes (a) an extracorporeal blood circuit having an arterial blood line, which leads from an arterial patient connection to a first chamber of a dialyzer or filter divided by a membrane into the first chamber and a second chamber, and a venous blood line, which leads from the first chamber of the dialyzer or filter to a venous patient connection, (b) a substitution fluid supply line configured to supply substitution fluid at an arterial admission point upstream of the dialyzer or filter, at which point substitution fluid is fed to the extracorporeal blood circuit for a pre-dilution, and/or at a venous admission point downstream of the dialyzer or filter, at which point substitution fluid is fed to the extracorporeal blood circuit for a post-dilution, (c) a blood pump configured to convey blood in the extracorporeal blood circuit, and (d) a bubble trap disposed in the venous blood line, comprising:

• filling the part of the extracorporeal blood circuit that lies between the arterial patient connection and the arterial admission point of the extracorporeal blood circuit with a fluid;
• feeding a fluid to the extracorporeal blood circuit via the substitution fluid line connected either to the arterial or the venous admission point until such time as a predetermined fluid level has become established in the bubble trap;
• putting the blood pump configured to convey the fluid in the extracorporeal blood circuit into operation;
• monitoring the fluid level in the bubble trap;
• and
• determining, based on the monitoring, that (a) there is a connection of the substitution fluid line to the arterial admission point if the fluid level in the bubble trap does not fall below a predetermined level or (b) there is a connection of the substitution fluid line to the venous admission point if the fluid level in the bubble trap falls below the predetermined level.

A device for checking the supply of substitution fluid for an extracorporeal blood treatment apparatus, the extracorporeal blood treatment apparatus including (a) an extracorporeal blood circuit which comprises an arterial blood line that leads from an arterial patient connection to a first chamber of a dialyzer or filter divided by a membrane into the first chamber and a second chamber, and a venous blood line that leads from the first chamber of the dialyzer or filter to a venous patient connection, (b) a substitution fluid supply line for supplying substitution fluid at an arterial admission point upstream of the dialyzer or filter, at which point substitution fluid is fed to the extracorporeal blood circuit for a pre-dilution, and/or at a venous admission point downstream of the dialyzer or filter, at which point substitution fluid is fed to the extracorporeal blood circuit for a post-dilution, (c) a blood pump configured to convey blood in the extracorporeal blood circuit, (d) a bubble trap disposed in the venous blood line, and (e) a monitoring device configured to monitor the fluid level in the bubble trap, comprising:

• an evaluation unit configured to cooperate with the monitoring device such that (a) the presence of a connection of the substitution fluid line to the arterial admission point is determined if the fluid level in the bubble trap does not fall below a predetermined level or (b) the presence of a connection of the substitution fluid line to the venous admission point is determined if the fluid level in the bubble trap falls below the predetermined level.

An extracorporeal blood treatment apparatus, comprising:

• an extracorporeal blood circuit having an arterial blood line that leads from an arterial patient connection to a first chamber of a dialyzer or filter divided by a membrane into the first chamber and a second chamber, and a venous blood line that leads from the first chamber of the dialyzer or filter to a venous patient connection;
• a substitution fluid supply line configured to supply substitution fluid at an arterial admission point upstream of the dialyzer or filter, at which point substitution fluid is fed to the extracorporeal blood circuit for a pre-dilution, and/or at a venous admission point downstream of the dialyzer or filter, at which point substitution fluid is fed to the extracorporeal blood circuit for a post-dilution;
• a blood pump configured to convey blood in the extracorporeal blood circuit;
• a bubble trap disposed in the venous blood line;
• a monitoring device configured to monitor the fluid level in the bubble trap;
• and
• a device configured to check the supply of substitution fluid, the device including an evaluation unit configured to cooperate with the monitoring device such that (a) the presence of a connection of the substitution fluid line to the arterial admission point is determined if the fluid level in the bubble trap does not fall below a predetermined level or (b) the presence of a connection of the substitution fluid line to the venous admission point is determined if the fluid level in the bubble trap falls below the predetermined level.