The disclosed subject matter relates to extracorporeal blood processing or other processing of fluids. Volumetric fluid balance, a required element of many such processes, may be achieved with multiple pumps or other proportioning or balancing devices which are to some extent independent of each other. This need may arise in treatments that involve multiple fluids. Safe and secure mechanisms to ensure fluid balance in such systems are described.

An extracorporeal blood treatment device and a method are provided for removing a secondary membrane formed on a semipermeable membrane of a dialyzer during an extracorporeal blood treatment. The extracorporeal blood treatment device operates in a first operating mode in which a dialysate outlet valve is open such that dialysate flows through a dialyzer feed line, through a dialysate chamber, and into and through a dialyzer discharge line. The extracorporeal blood treatment device operates in a second operating mode to remove the secondary membrane from the semipermeable membrane. During the second operating mode, the dialysate outlet valve is closed for a duration of time such that dialysate is prevented from flowing through the dialyzer discharge line. A backflush procedure results wherein a volume of dialysate passes from the dialysate chamber through the semipermeable membrane and into the blood chamber.

A system and method for balancing flows of renal replacement fluid is disclosed. The method uses pressure controls and pressure sensing devices to more precisely meter and balance the flow of fresh dialysate and spent dialysate. The balancing system may use one or two balancing devices, such as a balance tube, a tortuous path, or a balance chamber.

The disclosed subject matter relates to extracorporeal blood processing or other processing of fluids. Volumetric fluid balance, a required element of many such processes, may be achieved with multiple pumps or other proportioning or balancing devices which are to some extent independent of each other. This need may arise in treatments that involve multiple fluids. Safe and secure mechanisms to ensure fluid balance in such systems are described.

A blood purification apparatus that includes a blood circuit including an arterial blood circuit and a venous blood circuit and that allows a patient's blood to extracorporeally circulate, with a blood purifier that is interposed between the arterial blood circuit and the venous blood circuit and purifies; a dialysate temporary chamber that temporarily stores dialysate received from a dialysate storage supported by a supporting unit; a substitution-fluid temporary chamber that temporarily stores substitution fluid received from a substitution-fluid storage supported by the supporting unit; a first dialysate introduction line through which the dialysate in the dialysate storage flows into the dialysate temporary chamber; and a substitution line through which the substitution fluid in the substitution-fluid storage flows into the substitution-fluid temporary chamber. The blood purification apparatus includes a dialysate transfer pump provided to the first dialysate introduction line and that transfers the dialysate in the dialysate storage to the dialysate temporary chamber, a substitution-fluid transfer pump provided to the substitution line and that transfers the substitution fluid in the substitution-fluid storage to the substitution-fluid temporary chamber, and a control unit that controls the dialysate transfer pump and the substitution-fluid transfer pump.

The invention provides a blood treatment device comprising: a dialyser; an inlet pump assembly; an outlet pump assembly; and a control system. The inlet pump assembly configured to deliver a first volume of dialysate from a dialysate source to the dialyser in an inlet pump cycle having a dialysate delivery stroke. The outlet pump assembly configured to remove a second volume of dialysate from the dialyser and deliver the dialysate away from the dialyser in an outlet pump cycle having a dialysate removal stroke. The control system is configured to operate the inlet pump assembly in the inlet pump cycle, and configured to operate the outlet pump assembly in the outlet pump cycle. For each inlet pump cycle there is a corresponding outlet pump cycle, and each inlet pump assembly dialysate delivery stroke has a commencement time t.sub.1 and a termination time h, and each outlet pump assembly dialysate removal stroke has a commencement time t.sub.3 and a termination time t.sub.4. The blood treatment device is operable such that either: each dialysate removal stroke commencement time t.sub.3 is after the respective corresponding dialysate delivery stroke commencement time ti and before the respective corresponding dialysate delivery stroke termination time t.sub.2; or each dialysate delivery stroke commencement time t.sub.1 is after the respective corresponding dialysate removal stroke commencement time t.sub.3 and before the respective corresponding dialysate removal stroke termination time t.sub.4.

It is described an extracorporeal blood treatment apparatus (1) with a user interface (12) device capable configuring and allowing execution of one or more isolated ultrafiltration tasks during the course of a dialysis treatment. The extracorporeal blood treatment apparatus (1) is controlled in a normal mode, where dialysis fluid is fed to the blood treatment unit (2), and in an isolated ultrafiltration mode, where fresh dialysis fluid is no longer fed to the blood treatment unit (2).

Systems, methods, and/or apparatuses may be operative to perform a dialysis process that includes a displacer infusion process. The dialysis machine may include at least one processor and a memory coupled to the at least one processor, the memory comprising instructions that, when executed by the processor, may cause the at least one processor to access dialysis information for a dialysis process performed by a dialysis machine, the dialysis information indicating a target substance to be displaced from a binding compound by a displacer, and determine an infusion profile for infusing the displacer into a patient during a displacer infusion process of the dialysis process, the infusion profile determined based on the dialysis information and an infusion constraint. Other embodiments are described.

A CRRT apparatus comprising a filtration unit (2), a blood circuit (17), a blood pump (21), a dialysate line (13) and one or more lines (8; 51; 57; 58; 63; 69; 67; 74) to transfer a respective solution into blood; a fluid source for each of said one or more lines, wherein said solution comprises at least one buffer agent in the form of bicarbonate or bicarbonate precursor. A control unit (12) is configured to receive a patient prescription and to determine a parameter (J.sub.buffer_load/BW) indicative of a steady state acid-base balance in the blood of the patient who has to undergo a CRRT blood treatment, wherein said parameter is determined as a function of the concentration of said buffer agent in said fluid source and as a function of the estimated or calculated patient systemic steady state concentration of bicarbonate and/or bicarbonate precursors.

Systems, methods, and/or apparatuses may be operative to perform a dialysis process that includes a displacer infusion process. The dialysis machine may include at least one processor and a memory coupled to the at least one processor, the memory comprising instructions that, when executed by the processor, may cause the at least one processor to access dialysis information for a dialysis process performed by a dialysis machine, the dialysis information indicating a target substance to be displaced from a binding compound by a displacer, and determine an infusion profile for infusing the displacer into a patient during a displacer infusion process of the dialysis process, the infusion profile determined based on the dialysis information and an infusion constraint. Other embodiments are described.