Proportioning system for bicarbonate dialysate

Claim 2

A proportioning system for compounding a bicarbonate-containing dialysate suitable for use in a dialysis cell which system comprises a source of aqueous sodium carbonate concentrate; a source of aqueous hydrochloric acid-containing concentrate; a source of physiologically tolerable water; means for commingling an aqueous stream from each of said sources to provide a bicarbonate-containing dialysate stream for said dialysis cell; means for monitoring hydrogen ion activity in the produced dialysate and providing an output indicative of said activity; conductivity sensing means for monitoring the conductivity of the produced dialysate and providing an output indicative of said conductivity; and flow control means operably associated with the means for monitoring hydrogen ion activity and the conductivity sensing means, individually responsive to each of said outputs and interrupting normal flow of said dialysate when the value of either of said outputs deviates from a set magnitude by a predetermined amount.

Claim 3

The system in accordance with claim 1 wherein said means for monitoring hydrogen ion activity is a pH probe.

Claim 4

The system in accordance with claim 1 wherein said flow control means is a by-pass valve adapted to divert the dialysate to drain.

Claim 5

A proportioning system for compounding in situ a bicarbonate-containing dialysate suitable for use in a dialysis cell and comprising: a source of aqueous carbonate ion concentrate; a source of aqueous hydrochloric acid-containing concentrate; a source of condition water; a first mixing tank means for combining a stream of said aqueous carbonate ion concentrate with a stream of said water to produce a diluted aqueous carbonate solution; metering pump means for introducing said aqueous carbonate ion concentrate stream into said first mixing tank means; first temperature-compensated conductivity probe associated with said first mixing tank means and operably connected to said metering pump means to control the rate at which said aqueous carbonate ion concentrate is introduced into said first mixing tank means; a stabilization chamber downstream from said first mixing tank means for receiving said diluted aqueous carbonate solution; second temperature-compensation conductivity probe downstream from said stabilization chamber for monitoring conductivity of the stream of diluted aqueous carbonate solution withdrawn from said stabilization chamber and providing an output signal representative of the conductivity of said diluted aqueous carbonate stream; second mixing tank means for combining the stream of diluted aqueous carbonate solution withdrawn from said stabilization chamber with a stream of said aqueous acid concentrate to form a stream of said bicarbonate-containing dialysate; means for monitoring hydrogen ion activity in said dialysate stream and providing an output signal representative of said hydrogen ion activity; dialysate conductivity sensing means for monitoring conductivity of said dialysate stream and providing an output signal representative of the conductivity thereof; control means operably associated with at least said second temperature-compensated conductivity probe, said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means to receive the respective output signals therefrom and to generate a control signal in response thereto; and dialysate flow control means downstream from said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means and adapted to interrupt flow of said dialysate stream to the dialysis cell in response to said control signal.

Claim 6

A proportioning system for compounding in situ a bicarbonate-containing dialysate suitable for use in a dialysis cell and comprising: a source of aqueous carbonate ion concentrate; a source of aqueous hydrochloric acid-containing concentrate; a source of condition water; a first mixing tank means for combining a stream of said aqueous carbonate ion concentrate with a stream of said water to produce a diluted aqueous carbonate solution; metering pump means for introducing said aqueous carbonate ion concentrate stream into said first mixing tank means; first temperature-compensated conductivity probe associated with said first mixing tank means and operably connected to said metering pump means to control the rate at which said aqueous carbonate ion concentrate is introduced into said first mixing tank means; a stabilization chamber downstream from said first mixing tank means for receiving said diluted aqueous carbonate solution; second temperature-compensation conductivity probe downstream from said stabilization chamber for monitoring conductivity of the stream of diluted aqueous carbonate solution withdrawn from said stabilization chamber and providing an output signal representative of the conductivity of said diluted aqueous carbonate stream; second mixing tank means for combining the stream of diluted aqueous carbonate solution withdrawn from said stabilization chamber with a stream of said aqueous acid concentrate to form a stream of said bicarbonate-containing dialysate; means for monitoring hydrogen ion activity in said dialysate stream and providing an output signal representative of said hydrogen ion activity; dialysate conductivity sensing means for monitoring conductivity of said dialysate stream and providing an output signal representative of the conductivity thereof; control means operably associated with at least said second temperature-compensated conductivity probe, said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means to receive the respective output signals therefrom and to generate a control signal in response thereto; and dialysate flow control means downstream from said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means and adapted to interrupt flow of said dialysate stream to the dialysis cell in response to said control signal.

Claim 7

The proportioning system in accordance with claim 4 wherein said means for monitoring hydrogen ion activity is a pH probe.

Claim 8

The proportioning system in accordance with claim 5 wherein the pH probe is temperature-compensated.

Claim 9

A proportioning system for compounding in situ a bicarbonate-containing dialysate suitable for hemodialysis and comprising: a source of aqueous carbonate ion concentrate; a source of aqueous hydrochloric acid-containing concentrate; a source of conditioned water; mixing tank means for combining a stream of said aqueous carbonate ion concentrate with a stream of conditioned water from said respective sources to produce a diluted aqueous carbonate solution; carbonate metering pump means for introducing said stream of aqueous carbonate ion concentrate into said mixing tank means; stabilization chamber downstream from said mixing tank means for receiving said diluted aqueous carbonate solution; temperature-compensated conductivity probe downstream from said stabilization chamber for monitoring conductivity of the stream of diluted aqueous carbonate solution withdrawn from said stabilization chamber and providing an output signal representative of the conductivity of said diluted aqueous carbonate stream; dialysate mixing tank means for combining said withdrawn stream of diluted aqueous carbonate solution with a stream of said aqueous acid concentrate to form a stream of said bicarbonate-containing dialysate; means for monitoring hydrogen ion activity in said dialysate stream and providing an output signal representative of said hydrogen ion activity; metering pump control means associated with said carbonate metering pump means and responsive to said output signal from said means for monitoring hydrogen ion activity; dialysate conductivity sensing means for monitoring conductivity of said dialysate stream and providing an output signal representative of the conductivity thereof; control means operably associated with said temperature-compensated conductivity probe, said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means, to receive the respective output signals therefrom and to generate a control signal in response thereto; and dialysate flow control means downstream from said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means, and adapted to interrupt flow of said dialysate stream to a dialysis cell in response to said control signal.

Claim 10

A proportioning system for compounding in situ a bicarbonate-containing dialysate suitable for hemodialysis and comprising: a source of aqueous carbonate ion concentrate; a source of aqueous hydrochloric acid-containing concentrate; a source of conditioned water; mixing tank means for combining a stream of said aqueous carbonate ion concentrate with a stream of conditioned water from said respective sources to produce a diluted aqueous carbonate solution; carbonate metering pump means for introducing said stream of aqueous carbonate ion concentrate into said mixing tank means; stabilization chamber downstream from said mixing tank means for receiving said diluted aqueous carbonate solution; temperature-compensated conductivity probe downstream from said stabilization chamber for monitoring conductivity of the stream of diluted aqueous carbonate solution withdrawn from said stabilization chamber and providing an output signal representative of the conductivity of said diluted aqueous carbonate stream; dialysate mixing tank means for combining said withdrawn stream of diluted aqueous carbonate solution with a stream of said aqueous acid concentrate to form a stream of said bicarbonate-containing dialysate; means for monitoring hydrogen ion activity in said dialysate stream and providing an output signal representative of said hydrogen ion activity; metering pump control means associated with said carbonate metering pump means and responsive to said output signal from said means for monitoring hydrogen ion activity; dialysate conductivity sensing means for monitoring conductivity of said dialysate stream and providing an output signal representative of the conductivity thereof; control means operably associated with said temperature-compensated conductivity probe, said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means, to receive the respective output signals therefrom and to generate a control signal in response thereto; and dialysate flow control means downstream from said means for monitoring hydrogen ion activity and said dialysate conductivity sensing means, and adapted to interrupt flow of said dialysate stream to a dialysis cell in response to said control signal.

Claim 11

The proportioning system in accordance with claim 1 wherein the means for monitoring hydrogen ion activity is a pH probe.

Claim 12

The proportioning system in accordance with claim 8 wherein the pH probe is temperature-compensated.

Claim 15

The device in accordance with claim 10 wherein said first and second conductivity probes are temperature-compensated.

Claim 16

The device in accordance with claim 10 wherein said metering pump has a dispensing capacity of zero to about 50 milliliters per minute.

Claim 17

The device in accordance with claim 10 wherein said exit conduit also communicates with a proportioning unit in a dialysis machine.

Claim 20

The method in accordance with claim 14 wherein said sodium carbonate solution has a carbonate ion concentration of about 0.8 Normal to about 1.6 Normal.

Claim 21

The method in accordance with claim 14 wherein said sodium carbonate solution has a carbonate ion concentration of about 0.85 Normal to about 1.35 Normal.

Claim 22

The method in accordance with claim 14 wherein said aqueous hydrochloric acid-containing solution has a hydrogen ion concentration of about 11 to about 12 Normal.

Claim 23

The method in accordance with claim 14 wherein said aqueous sodium carbonate solution is diluted by comining a stream thereof with a stream of physiologically tolerable water at a volumetric rate determined by conductivity of the diluted solution.

Claim 24

The method in accordance with claim 14 wherein said aqueous sodium carbonate solution is diluted by combining a stream thereof with a stream of physiologically tolerable water at a volumetric rate determined by pH of the resulting dialysate.