Peritoneal dialysis cycler having disinfection

1. A dialysis system comprising:

a dialysis fluid metering pump;

a first volumetric balancing chamber including a first fixed volume chamber and a first diaphragm positioned and arranged to extend back and forth within the first fixed volume chamber;

a first outlet line extending between the first volumetric balancing chamber and an inlet to the dialysis fluid metering pump;

a second outlet line extending between the first volumetric balancing chamber and a drain line;

a first inlet line extending between the first volumetric balancing chamber and an outlet from the dialysis fluid metering pump;

a second inlet line extending between the first volumetric balancing chamber and a used dialysis fluid line;

a second volumetric balancing chamber including a second fixed volume chamber and a second diaphragm positioned and arranged to extend back and forth within the second fixed volume chamber;

a first outlet line extending between the second volumetric balancing chamber and an inlet to the dialysis fluid metering pump;

a second outlet line extending between the second volumetric balancing chamber and a drain line;

a first inlet line extending between the second volumetric balancing chamber and an outlet from the dialysis fluid metering pump; and

a second inlet line extending between the second volumetric balancing chamber and a used dialysis fluid line.

2. The dialysis system of claim 1 , which is a hemodialysis (“HD”) system configured to deliver fresh HD fluid to a dialyzer via the dialysis fluid metering pump pulling fresh HD fluid from at least one of the first or second volumetric balancing chambers via respective first outlet line.

3. The HD system of claim 2 , which is configured such that pulling fresh HD fluid from at least one of the first or second volumetric balancing chambers via respective first outlet line causes used dialysis fluid to fill at least one of the first or second volumetric balancing chambers via respective second inlet line extending between the first or second volumetric balancing chamber and the used dialysis fluid line.

4. The HD system of claim 2 , which includes an inline dialysis fluid heater located upstream or downstream from the dialysis fluid metering pump.

5. The HD system of claim 2 , which is configured to repeat pulling of the fresh HD fluid from at least one of the first or second volumetric balancing chambers until a desired amount of fresh HD fluid is delivered to the dialyzer.

6. The HD system of claim 5 , which is configured such that at least one of the first or second volumetric balancing chambers is replenished with fresh HD fluid prior to repeating delivery of the fresh HD fluid to the dialyzer.

7. The dialysis system of claim 1 , which is a hemodialysis (“HD”) system configured to deliver used HD fluid to the drain line via respective second outlet line and via the dialysis fluid metering pump pushing fresh HD fluid to at least one of the first or second volumetric balancing chambers via respective first inlet line.

8. The HD system of claim 7 , which is configured such that used HD fluid is precluded from flowing along the used dialysis fluid line when the used HD fluid is delivered to the drain line.

9. The dialysis system of claim 1 , which is a hemodialysis (“HD”) system configured to perform an ultrafiltration (“UF”) stroke via pushing used HD fluid to the drain line without a corresponding delivery of fresh HD fluid to a dialyzer.

10. The HD system of claim 9 , which is configured such that the UF stroke occurs via the dialysis fluid metering pump pulling fresh HD fluid from one of the first or second volumetric balancing chambers and pushing the fresh HD fluid to the other of the first or second volumetric balancing chambers, thereby pushing used HD fluid to the drain line without a corresponding delivery of fresh HD fluid to the dialyzer.

11. The HD system of claim 10 , which is configured such that the pulling of fresh HD fluid from one of the first or second volumetric balancing chambers by the dialysis fluid metering pump correspondingly pulls used HD fluid into the first or second volumetric balancing chamber.

12. The HD system of claim 10 , which is configured to repeat the UF stroke, or a partial UF stroke, until a desired amount of UF is removed to the drain line.

13. The dialysis system of claim 1 , which is a peritoneal dialysis (“PD”) system, wherein fresh PD fluid is delivered to a patient line via the dialysis fluid metering pump.

14. The PD system of claim 13 , which is configured to rely on the accuracy of the dialysis fluid metering pump to pump a prescribed amount of fresh PD fluid to the patient.

15. The PD system of claim 13 , which is configured to perform a patient dwell after delivering a prescribed amount of fresh PD fluid to the patient.

16. The PD system of claim 13 , which is configured to perform a patient drain in which used PD fluid is delivered to and removed from at least one of the first or second volumetric balancing chambers.

17. The PD system of claim 13 , which is configured to determine an amount of excess fluid removed from the patient by subtracting an amount of fresh PD fluid delivered to the patient line from an amount of used PD fluid removed from the patient.

18. The PD system of claim 13 , which is (i) a continuous cycling peritoneal dialysis (“CCPD”) system, wherein the patient line includes a fresh leg and a used leg, or (ii) a continuous flow peritoneal dialysis (“CFPD”) system, in which the patient line is separated into a fresh PD fluid patient line and a used PD fluid patient line.