Dialysis machine and method of operating a dialysis machine
AssigneeFresenius Medical Care Deutschland GmbH
InventorsKlaus Balschat, Michael Koch, Elmar Wolter
Life of this patent
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Abstract
A machine and method for preparing dialysis fluid for a dialysis machine. Fresh water is mixed with one or more dialysis fluid concentrates. The mixture of water and concentrates is conveyed into an equalizing chamber by a proportioning unit at a predetermined flow rate independent of the dialysate flow rate. Metered addition of the concentrates is performed volumetrically and is monitored on the basis of the conductivity of the dialysis fluid, which is measured by conductivity sensors. Because the mixture of water and concentrates is always conveyed at the same flow rate, the composition of the dialysis fluid can be determined with a high accuracy and the proportioning can be performed accurately.
Claims20
A dialysis machine comprising:
- a dialyzer subdivided by a semipermeable membrane into a chamber for a liquid to be purified and a dialysis fluid chamber;
- a dialysis fluid inlet line leading to an inlet of the dialysis fluid chamber;
- a dialysis fluid outlet line leading away from an outlet of the dialysis fluid chamber;
- a balancing system connected to the dialysis fluid inlet and outlet lines for balancing fresh and spent dialysis fluid;
- and
- a proportioning device for supplying fresh dialysis fluid, the proportioning device comprising:
- a water source;
- at least one proportioning unit having a first chamber half and second chamber half configured to operate so that liquid is displaced from one chamber half when the other chamber half is filled with liquid;
- a proportioning unit inlet line leading from the water source, the proportioning unit inlet line connected to an inlet of the first chamber half and an inlet of the second chamber half, and a proportioning unit outlet line connected to an outlet of the first chamber half and an outlet of the second chamber half, so that the chamber halves can be alternately filled and emptied;
- at least one mixing point provided in at least one of the proportioning unit inlet line and the proportioning unit outlet line;
- at least one dialysis fluid concentrate source for supplying a fluid concentrate to the at least one mixing point for forming a fresh dialysis fluid;
- and
- an equalizing chamber for the fresh dialysis fluid, the equalizing chamber connected to the proportioning unit outlet line, wherein the equalizing chamber provides a variable buffer volume between the proportioning unit and the balancing system such that the flow rate of a dialysis fluid through the dialysis fluid chamber has no effect on the flow rate of the fresh dialysis fluid in the proportioning unit outlet line.
A method of operating a dialysis machine, comprising the steps of:
- sending fresh dialysis fluid to a dialysis fluid chamber of a dialyzer, the chamber divided by a semipermeable membrane into the dialysis fluid chamber and a chamber for the liquid to be purified;
- removing dialysis fluid from the dialysis fluid chamber;
- and
- balancing spent and fresh dialysis fluid in a balancing system whereby the fresh dialysis fluid is prepared by:
- filling alternately a first and a second chamber half of at least one proportioning unit with at least one of water and a mixture of water and at least one dialysis fluid concentrate;
- discarding a liquid from the other chamber half;
- adding at least one dialysis fluid concentrate to the liquid discarded from the other chamber half and a liquid supplied to the chamber to prepare the fresh dialysis fluid;
- collecting the fresh dialysis fluid in an equalizing chamber before the fresh dialysis fluid is sent to the dialysis fluid chamber, wherein the equalizing chamber provides a variable buffer volume between the at least one proportioning unit and the balancing system such that the flow rate of the dialysis fluid through the dialysis fluid chamber has no effect on the flow rate of the fresh dialysis fluid into the equalizing chamber.
Dependencies are inferred from the claim text.