Renal failure therapy machines and methods including convective and diffusive clearance

A renal failure therapy method comprising:

• placing a sorbent device in fluid communication with a blood cleaning filter;
• regenerating used therapy fluid from the blood cleaning filter with the sorbent device;
• causing the regenerated therapy fluid to flow back to the blood cleaning filter;
• restricting flow to cause the regenerated therapy fluid to be pressed through a membrane of the blood cleaning filter into an extracorporeal circuit so that a first amount of the regenerated therapy fluid to the blood cleaning filter performs convective clearance;
• and
• using the blood cleaning filter to cause a second amount of the regenerated therapy fluid to the blood cleaning filter to perform diffusive clearance.

A renal failure therapy machine comprising:

• a blood circuit including a blood cleaning filter;
• a therapy fluid circuit including a balance chamber, the balance chamber including a fresh therapy fluid compartment configured to send fresh therapy fluid to the blood cleaning filter and a used therapy fluid compartment configured to receive used therapy fluid from the blood cleaning filter;
• a first pump configured to pump fresh therapy fluid to the fresh therapy fluid compartment of the balance chamber;
• a second pump configured to pump used therapy fluid to the used therapy fluid compartment of the balance chamber;
• and
• a pneumatically actuated flow restrictor in fluid communication with the balance chamber and the blood cleaning filter, the flow restrictor pneumatically actuated to cause fresh therapy fluid traveling from the fresh therapy fluid compartment of the balance chamber to the blood cleaning filter to be pressurized so that a first amount of the fresh therapy fluid performs convective clearance and a second amount of the fresh therapy fluid performs diffusive clearance.