Peritoneal dialysate flow path sensing

1. A peritoneal dialysis cycler, comprising:

a combined infusion and effluent line for delivering and receiving a peritoneal dialysate to and from a peritoneal cavity;

at least one pump positioned in the combined infusion and effluent line;

at least one valve fluidly connecting the combined infusion and effluent line to a sampling flow path; the sampling flow path fluidly connected to at least one sensor, wherein the at least one sensor is selected from the group consisting of: an ion selective electrode, a pH sensor, a refractive index sensor, and a conductivity sensor; and

a processor in communication with the at least one sensor; the processor programmed to determine a concentration of at least one solute in a peritoneal dialysate removed from a patient based on data from the at least one sensor and to determine an end time for a peritoneal dialysis cycle based on the concentration of the at least one solute.

2. The peritoneal dialysis cycler of claim 1 , further comprising a detachable sampling reservoir fluidly connected to the sampling flow path.

3. The peritoneal dialysis cycler of claim 1 , further comprising a peritoneal dialysate generation flow path fluidly connected to the combined infusion and effluent line; the peritoneal dialysate generation flow path having:

a water source;

a water purification module;

at least one concentrate source fluidly connected to the peritoneal dialysate generation flow path; and

at least one sensor positioned in the peritoneal dialysate generation flow path or combined infusion and effluent line.

4. The peritoneal dialysis cycler of claim 3 , further comprising a dialysate regeneration module; the dialysate regeneration module fluidly connected to the combined infusion and effluent line and the peritoneal dialysate generation flow path.

5. The peritoneal dialysis cycler of claim 4 , wherein the dialysate regeneration module is positioned downstream of the sampling flow path.

6. The peritoneal dialysis cycler of claim 1 , the processor receiving data from the at least one sensor and storing the data in a machine-readable storage medium.

7. The peritoneal dialysis cycler of claim 6 , the processor comprising an input/output interface, the input/output interface transmitting data from the at least one sensor to a user.

8. The peritoneal dialysis cycler of claim 1 , further comprising a sampling port fluidly connected to the sampling flow path.

9. The peritoneal dialysis cycler of claim 8 , wherein the sampling port is covered by a pierceable septum.

10. The peritoneal dialysis cycler of claim 1 , wherein the combined infusion and effluent line comprises separate flow paths.

11. The system of claim 1 , the sampling flow path fluidly connected to at least a second sensor selected from the group consisting of a flow sensor, a pressure sensor, and a temperature sensor.

12. A method, comprising the steps of:

infusing peritoneal dialysate into a patient through a combined infusion and effluent line;

removing peritoneal dialysate from the patient through the combined infusion and effluent line;

operating at least one valve to direct at least a portion of the fluid in the combined infusion and effluent line into a sampling flow path;

determining a concentration of at least one solute in the peritoneal dialysate in the sampling flow path with at least one sensor; the at least one sensor selected from the group consisting of: an ion selective electrode, a pH sensor, a refractive index sensor, and a conductivity sensor; and

determining an end time for a peritoneal dialysis cycle based on the concentration of the at least one solute.

13. The method of claim 12 , further comprising the step of pumping the peritoneal dialysate from the sampling flow path to a sampling reservoir; wherein the step of determining the concentration of the at least one solute in the peritoneal dialysate of the peritoneal dialysate in the sampling flow path comprises determining the concentration of the at least one solute in the peritoneal dialysate in the peritoneal dialysate in the sampling reservoir.

14. The method of claim 13 , further comprising the step of adding one or more reagents to the peritoneal dialysate in the sampling reservoir prior to determining the concentration of the at least one solute in the peritoneal dialysate.

15. The method of claim 12 , further comprising the step of removing a portion of fluid from the sampling flow path through a sampling port, wherein the step of determining the concentration of the at least one solute in the peritoneal dialysate comprises determining the concentration of the at least one solute in the removed fluid.

16. The method of claim 12 , further comprising the step of determining at least one fluid characteristic in the peritoneal dialysate in the combined infusion and effluent line.

17. The method of claim 16 , wherein at least one fluid characteristic is determined in the combined infusion and effluent line.

18. The method of claim 17 , wherein the at least one fluid characteristic is selected from the group of a pH of the fluid, and a volume of the fluid.

19. The method of claim 12 , comprising the steps of directing a portion of the peritoneal dialysate from the patient from the combined infusion and effluent line to the sampling flow path at a first time during a peritoneal dialysis cycle; directing a portion of the peritoneal dialysate from the patient from the combined infusion and effluent line to the sampling flow path at a second time; and determining the concentration of the at least one solute in the peritoneal dialysate at the first time and the second time.

20. The method of claim 12 , further comprising the step of communicating the concentration of the at least one solute in the peritoneal dialysate to a machine-readable storage medium in a processor.

21. The method of claim 12 , wherein the combined infusion and effluent lines are separate lines.