Method and device for supplying ready-to-use dialysis fluid

A method of supplying ready-to-use dialysis fluid in extracorporeal blood treatment, comprising the steps of:

• (a) providing blood to be treated to an extracorporeal blood treatment machine having:
• a dialyzer divided by a semipermeable membrane into a dialysis fluid chamber connected to a dialysis fluid path and having a dialysis fluid chamber inlet and a dialysis fluid chamber outlet and a blood chamber connected to a blood path, the dialysis fluid path having a dialysis fluid inlet line and a dialysis fluid outlet line;
• a fluid filter provided in the dialysis fluid path, the fluid filter divided by a microbe-retaining membrane into a first filter chamber and a second filter chamber, the first filter chamber having an inlet and each filter chamber having an outlet;
• a first bypass line, having a first bypass valve and providing fluid connection between the first filter chamber outlet and the dialysis fluid outlet line;
• a second bypass line, having a second bypass valve and providing fluid connection between the dialysis fluid inlet line and the dialysis fluid outlet line;
• a measuring device provided in the dialysis fluid outlet line downstream of the first bypass line, the measuring device capable of measuring a dialysis fluid parameter selected from the group consisting of temperature and conductivity, and of generating a signal in response to the measured parameter;
• and
• a comparing device connected to the measuring device arranged and composed for receiving a signal from the measuring device and calculating the difference between the measured dialysis fluid parameter and a predetermined value for the parameter;
• (b) providing fresh dialysis fluid to the dialysis fluid path with the first and second bypass valves closed such that fluid flows through the fluid filter and the dialysis inlet line into the dialysis fluid chamber, through the dialysis fluid outlet line and the measuring device and into the drain;
• (c) taking a first measurement of the dialysis fluid parameter;
• (d) opening the first bypass valve in response to a calculated difference exceeding a pre-set value, thereby diverting dialysis fluid through the first bypass line into the dialysis fluid outline line;
• (e) taking a second measurement of the dialysis fluid parameter;
• (f) closing the first bypass valve in response to a calculated value falling below the pre-set value, thereby interrupting flow through the first bypass line;
• and
• (g) opening the second bypass valve, thereby allowing fluid flow through the second bypass line into the dialysis fluid outline line.

A device for extracorporeal blood treatment comprising:

• a dialyzer divider by a semipermeable membrane into a dialysis fluid chamber connected to a dialysis fluid path and having,a dialysis fluid chamber inlet and a dialysis fluid chamber outlet and a blood chamber connected to a blood path, the dialysis fluid path having a dialysis fluid inlet line and a dialysis fluid outlet line;
• a fluid filter provided in the dialysis fluid path, the fluid filter divided by a microbe-retaining membrane into a first filter chamber and a second filter chamber, the first filter chamber having an inlet and each filter chamber having an outlet;
• a first bypass line, having a first bypass valve and providing fluid connection between the first filter chamber outlet and the dialysis fluid outlet line;
• a second bypass line, having a second bypass valve and providing fluid connection between the dialysis fluid inlet line and the dialysis fluid outlet line, the second bypass line being in fluid communication with the second filter chamber of the fluid filter;
• a measuring device provided in the dialysis fluid outlet line downstream of the first bypass line, the measuring device capable of measuring a dialysis fluid parameter selected from the group consisting of temperature and conductivity, and of generating a signal in response to the measured parameter;
• and
• a comparing device connected to the measuring device arranged and composed for receiving a signal from the measuring device and calculating the difference between the measured dialysis fluid parameter and a predetermined value for the parameter;
• wherein closing the first bypass valve and opening the second bypass valve diverts dialysis fluid through the second bypass line into the dialysis fluid outlet line and closing the second bypass valve allows dialysis fluid flow to the dialysis fluid chamber;
• and
• wherein a control device opens the second bypass valve when the first bypass valve is closed and closes the second bypass valve when the calculated difference falls below a pre-set limit value.