Medical fluid system with flexible sheeting disposable unit

1. A kidney failure therapy system comprising:

a dialysate supply;

at least one valve actuator;

at least one pump actuator; and

a disposable unit including first, second and third flexible sheets sealed together to form: (i) at least one flow path configured to be placed in fluid communication with the dilaysate supply and to operate with the at least one valve actuator; (ii) at least one membrane pumping portion configured to operate with the at least one pump actuator, and (iii) at least one balance chamber portion, wherein the first and third sheets are configured to be pulled outward towards first and second walls of the at least one balance chamber portion, the second sheet maintained between the first and third sheets and configured to be pushed back and forth towards the pulled-apart first and third sheets.

2. The kidney failure therapy system of claim 1 , wherein the pump actuator is a membrane pump actuator.

3. The kidney failure therapy system of claim 1 , which includes a heater, the flexible sheets sealed together of form: (i) a heating pathway configured to be placed in operable communication with the heater; or (ii) the at least one flow path configured to be in fluid communication with a warmer bag placed in operable communication with the heater.

4. The kidney failure therapy system of claim 1 , wherein the at least one flow path is in communication with at least one port sealed between the first and second flexible sheets, the port enabling fluid communication with an returned dialysate conduit.

5. The kidney failure therapy system of claim 1 , wherein the flow path includes at least one valve seat, the at least one valve seat configured to operate with the at least one valve actuator.

6. The kidney failure therapy system of claim 1 , which includes at least one sensor, and wherein the first, second and third sheets further cooperate to form at least one sensing area configured to operate with the at least one sensor.

7. The kidney failure therapy system of claim 1 , wherein at least two of the three sheets are sealed to form a blood flow pathway.

8. The kidney system of claim 1 , which is configured to flow fluid to both sides of the second sheet between the first and second balance chamber walls, respectively.

9. The kidney failure therapy system of claim 8 , which includes an enclosure housing the pump actuator and valve actuator, the enclosure including the first and second chamber walls.

10. The kidney failure therapy system of claim 8 , wherein the first and second sheets are sealed to define at least one inlet path and at least one outlet path in fluid communication with a first compartment formed between the first and second sheets.

11. The kidney failure therapy system of claim 10 , wherein the second and third sheets are sealed to define at least one inlet path and at least one outlet path in fluid communication with a second compartment formed between the second and third sheets.

12. The kidney failure therapy system of claim 10 , which includes at least one valve actuator coupled operably to the at least one inlet path and the at least one outlet path.

13. The kidney failure therapy system of claim 8 , wherein the pumping portion of the disposable unit is in fluid communication with the balance chamber portion of the disposable unit.

14. The kidney failure therapy system of claim 1 , the second sheet located between the first and third sheets, the at least one flow path having a first portion formed between the first and second sheets and a second portion formed between the second and third sheets, the second sheet defining an aperture enabling fluid communication between the first and second portions of the at least one flow path.

15. The kidney failure therapy system of claim 1 , wherein the first, second and third sheets are sealed together via at least one process selected from the group consisting of: (i) heat sealing; (ii) ultrasonic sealing; (iii) radio frequency sealing; (iv) solvent bonding; (v) adhesive bonding and (vi) mechanical clamping.

16. The kidney failure therapy system of claim 1 , wherein at least a portion of the first, second and third sheets is sealed together by activating an adhesive provided onto one of the first, second and third sheets.

17. The kidney failure therapy system of claim 16 , the second sheet located between the first and third sheets, the activated adhesive forming a first portion of the flow path between the first and second sheets, and a second portion of the flow path between the second and third sheets, the third sheet defining an aperture enabling fluid communication between the first and second portions.

18. The kidney failure therapy system of claim 8 , the second sheet located between the first and third sheets, the first sheet sealed to the second sheet without the second sheet being correspondingly sealed to the third sheet via controlling an amount of energy used during a sealing process used to achieve such sealing.

19. The kidney failure therapy system of claim 18 , wherein the first, second and third sheets form a first portion of the disposable unit and the first and second sheets only form a second portion of the disposable unit.

20. The kidney failure therapy system of claim 18 , which includes a mechanical clamping mechanism to form at least one seal between all three sheets.

21. A kidney failure therapy system comprising:

an extracorporeal circuit;

at least one valve actuator;

a blood pump actuator;

a dialysate pump actuator; and

a disposable unit including first and second flexible sheets sealed to each other to form: (i) at least one flow path configured to be placed in fluid communication with the extracorporeal circuit and to operate with the at least one valve actuator; (ii) a first membrane pumping portion configured to operate with the blood pump actuator; (iii) a second membrane pumping portion configured to operate with the dialysate pump actuator; and (iv) a balance chamber portion in fluid communication with the second membrane pumping portion.

22. The kidney failure therapy system of claim 21 , wherein the first and second sheets are sealed to form: (i) at least one blood inlet pathway; (ii) a to-pump pathway;

(iii) a from-pump pathway; (iv) at least one heater pathway; and (v) at least one patient pathway.

23. The kidney failure therapy system of claim 21 , wherein the disposable unit includes a third sheet, the three sheets sealed to form the balance chamber portion.

24. The kidney failure therapy system of claim 21 , wherein the first membrane pumping portion is a peristaltic membrane pumping portion.