Apparatus and Process for Testing Filters

An apparatus for testing a filter, comprising:

• a source of a fluid for an extracorporeal blood treatment;
• a supply line connected to the source;
• a blood treatment device having a semipermeable membrane which separates a fluid chamber connected to the supply line from a blood chamber connected to an extracorporeal blood circuit;
• a drainage line which connects the fluid chamber with a discharge of a used treatment fluid;
• a filter having a semipermeable membrane which separates a first chamber from a second chamber, the first chamber having at least a first fluid port connected to the supply line, the second chamber having at least a second fluid port connected to the supply line;
• means for generating a pressure gradient between the first chamber and the second chamber, the means for generating a pressure gradient comprising means for generating, in the first chamber, a pressure above atmospheric pressure, and means for generating, in the second chamber, a pressure below atmospheric pressure;
• means for monitoring a pressure in the first chamber and/or in the second chamber;
• a controller connected to the means for generating a pressure gradient and to the means for monitoring the pressure, and being programmed to carry out a process for testing the filter comprising the steps of:
• generating a pressure gradient between the first chamber and the second chamber, the first chamber having a first pressure which is above atmospheric pressure and the second chamber having a second pressure which is below atmospheric pressure;
• monitoring a pressure in the first chamber and/or in the second chamber.