Renal therapy blood cleansing system with balance chamber and bolus, rinseback or prime volume feature

1. A renal therapy blood cleansing system comprising:

a blood filtering device in communication with an extracorporeal circuit;

a first pump configured to pump fluid to the blood filtering device;

a second pump configured to pump fluid from the blood filtering device;

a balance chamber in fluid communication with first and second lines, the first and second lines in fluid communication with the first and second pumps, respectively, the balance chamber configured to exchange like volumes of fresh and spent fluid;

a plurality of valves; and

a control scheme programmed to operate the plurality of valves to enable spent fluid taken from the balance chamber through one of the first and second lines to be recirculated to the balance chamber through the other of the first and second lines to compensate for a volume of fresh fluid delivered to the blood filtering device.

2. The renal therapy blood cleansing system of claim 1 , which includes a plurality of balance chambers, each balance chamber having first and second lines in communication with the first and second pumps, respectively.

3. The renal therapy blood cleansing system of claim 2 , wherein the control scheme is configured to operate the plurality of valves to enable spent fluid taken from each of the balance chambers through one of the respective first and second lines to be recirculated to the balance chamber through the other of the first and second respective lines to compensate for a volume of fresh fluid delivered to the filtering device.

4. The renal therapy blood cleansing system of claim 2 , wherein the plurality of balance chambers form part of a match flow equalizer.

5. The renal therapy blood cleansing system of claim 1 , wherein the volume of fresh fluid is to provide a bolus volume, rinseback volume or prime volume.

6. The renal therapy blood cleansing system of claim 1 , which includes an ultrafiltration removal meter in communication with one of the first and second lines.

7. The renal therapy blood cleansing system of claim 1 , which includes an ultrafilter located upstream of the blood filtering device.

8. The renal therapy blood cleansing system of claim 1 , wherein the first pump is located upstream of the balance chamber and the second pump is located downstream of the blood filtering device.

9. The renal therapy blood cleansing system of claim 8 , wherein one of the plurality of valves is located between the second pump and the blood filtering device.

10. The renal therapy blood cleansing system of claim 8 , wherein one of the plurality of valves is located between the first pump and the balance chamber.

11. The renal therapy blood cleansing system of claim 1 , wherein first and second ones of the plurality of valves are located in the first and second lines connected to the blood filtering device.

12. A renal therapy blood cleansing system comprising:

a blood filtering device in communication with an extracorporeal circuit;

a first pump configured to pump fluid to the blood filtering device and the extracorporeal circuit;

a second pump configured to pump fluid from the blood filtering device;

a balance chamber in fluid communication with first and second lines, the first and second lines in fluid communication with the first and second pumps, respectively, the balance chamber configured to exchange like volumes of fresh and spent fluid;

a plurality of valves; and

a control scheme programmed to operate the plurality of valves to enable spent fluid taken from the balance chamber through one of the first and second lines to be recirculated to the balance chamber through the other of the first and second lines to compensate for a volume of fresh fluid delivered to the blood filtering device and the extracorporeal circuit.

13. The renal therapy blood cleansing system of claim 12 , wherein the volume of fresh fluid is to provide a bolus volume, rinseback volume or prime volume.

14. The renal therapy blood cleansing system of claim 12 , which includes at least one filter located between the first pump and the extracorporeal circuit.

15. The renal therapy blood cleansing system of claim 12 , which includes an ultrafiltration removal meter in communication with one of the first and second lines.

16. The renal therapy blood cleansing system of claim 12 , wherein the first pump is located upstream of the balance chamber and the second pump is located downstream of the blood filtering device.

17. A renal therapy blood cleansing system comprising:

a blood filtering device in communication with an extracorporeal circuit;

a first pump configured to pump fluid to the extracorporeal circuit;

a second pump configured to pump fluid from the blood filtering device;

a balance chamber in fluid communication with first and second lines, the first and second lines in fluid communication with the first and second pumps, respectively, the balance chamber configured to exchange like volumes of fresh and spent fluid;

a plurality of valves; and

a control scheme programmed to operate the plurality of valves to enable spent fluid taken from the balance chamber through one of the first and second lines to be recirculated to the balance chamber through the other of the first and second lines to compensate for a volume of fresh fluid delivered to the extracorporeal circuit.

18. The renal therapy blood cleansing system of claim 17 , wherein the volume of fresh fluid is to provide a bolus volume, rinseback volume or prime volume.

19. The renal therapy blood cleansing system of claim 17 , which includes at least one filter located between the first pump and the extracorporeal circuit.

20. The renal therapy blood cleansing system of claim 17 , which includes an ultrafiltration removal meter in communication with one of the first and second lines.

21. The renal therapy blood cleansing system of claim 17 , wherein the first pump is located upstream of the balance chamber and the second pump is located downstream of the blood filtering device.