Treatment of dialysate solution for removal of urea

Claim 2

The method as defined in claim 2 wherein the dialysate solution is circulated by pumping the dialysate solution past the artificial kidney membrane and through the column.

Claim 3

The method as defined in claim 1 in which the zirconium phosphate ion exchanger is added to the dialysate solution in particle form to produce a circulating slurry.

Claim 4

The method as defined in claim 1 in which the urease is added to the dialysate solution by being dissolved in the dialysate solution.

Claim 6

In a hemodialysis apparatus which includes an artificial kidney and a dialysate recirculating system adapted to circulate a dialysate solution through said artificial kidney and thereby pick up urea, said dialysate solution containing the amount of sodium ions required to prevent imbalance in the patient; urease in said recirculating system for converting the urea in said system to ammonia carbonate; and zirconium phosphate ion exchanger in said recirculating system for removing the ammonium ions from the ammonium carbonate to a low enough concentration to permit recirculation of the solution through said artificial kidney without addition of unacceptable amounts of ammonium ions to the patient.

Claim 7

In a method for treating a dialysate solution which circulates through an artificial kidney and thereby picks up urea, said solution containing the amount of sodium ions required to prevent imbalance in the patient; the improvement which resides in treating the dialysate solution with urease to convert urea to ammonium carbonate; and treating the dialysate solution with zirconium phosphate ion exchanger to remove the ammonium ions from the ammonium carbonate to a low enough concentration to permit recirculation of the solution through said artificial kidney without addition of unacceptable amounts of ammonium ions to the patient.

Claim 8

In a recirculating dialysate system containing a dialysate solution for receiving urea from an artificial kidney, a charge of urease serving to convert urea in the dialysate solution to ammonium carbonate, a charge of zirconium phosphate ion exchanger serving to remove ammonium ions from the ammonium carbonate, and means recirculating the dialysate solution from a urea receiving location in the artificial kidney through said charges and back to said urea receiving location.

Claim 9

A system according to claim 10 wherein said zirconium phosphate charge is contained in particle form within a column through which said dialysate solution passes.

Claim 10

A system according to claim 11 wherein said urease is adsorbed on the particles of zirconium phosphate ion exchanger.

Claim 11

A system according to claim 10 wherein said dialysate contains a predetermined amount of sodium ions.

Claim 12

In a method of treating a recirculating dialysate solution which picks up urea resulting from renal failure; the improvement which comprises treating the dialysate solution with urease to convert urea picked up by the dialysate solution to ammonium carbonate; and treating the dialysate solution with a zirconium phosphate ion exchanger to remove ammonium ions from the ammonium carbonate before the solution again picks up urea.

Claim 13

In an apparatus for treating A recirculating dialysate solution which picks up urea from a patient''s blood through a membrane of a kidney dialysis system; the improvement comprising urease in said apparatus adapted to convert urea picked up at said membrane by said dialysate solution to ammonium carbonate; and zirconium phosphate ion exchanger in said apparatus for removing ammonium ions from the ammonium carbonate before the solution again picks up urea.