A dialysis system includes a dialysis fluid metering pump; at least one volumetric balancing chamber including a first fixed volume chamber and a first diaphragm positioned and arranged to extend back and forth within the first volumetric balancing 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 peritoneal dialysis (PD) system includes 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, the first diaphragm separating a fresh PD fluid side from a used PD fluid side of the first volumetric balancing chamber; 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, the second diaphragm separating a fresh PD fluid side from a used PD fluid side of the second volumetric balancing chamber; and a PD fluid pump positioned and arranged to pump used PD fluid back and forth between the used PD fluid sides of the first and second volumetric balancing chamber.

A peritoneal dialysis system includes a control unit configured to cause (i) a fluid inlet valve and a fluid outlet valve to occlude a fluid inlet line and a fluid outlet line, respectively, while a linear actuator moves a piston to create a positive pressure within a pump housing, the positive pressure measured by a pressure sensor, and (ii) the fluid inlet valve to occlude the fluid inlet line and the fluid outlet valve to open the fluid outlet line, while the linear actuator moves the piston so as to maintain the positive pressure within the pump housing while fluid is pumped out of the fluid pump chamber via the opened fluid outlet line.

A peritoneal dialysis (PD) system includes 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, the first diaphragm separating a fresh PD fluid side from a used PD fluid side of the first volumetric balancing chamber; 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, the second diaphragm separating a fresh PD fluid side from a used PD fluid side of the second volumetric balancing chamber; and a PD fluid pump positioned and arranged to pump used PD fluid back and forth between the used PD fluid sides of the first and second volumetric balancing chamber.

A dialysis system includes a dialysis fluid metering pump; at least one volumetric balancing chamber including a first fixed volume chamber and a first diaphragm positioned and arranged to extend back and forth within the first volumetric balancing 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 pump device includes a supply chamber having a supply-side accommodation part; a drain chamber having a drain-side accommodation part; dividing membranes each being a flexible member that closes a corresponding one of the supply-side accommodation part and the drain-side accommodation part, the dividing membranes displaceable relative to the supply-side accommodation part and the drain-side accommodation part to cause dialysate to be suctioned into and discharged from the supply-side accommodation part through a liquid-supply-side connection port and cause drain liquid to be suctioned into and discharged from the drain-side accommodation part through a liquid-drain-side connection port; and a pump body from which the supply chamber or the drain chamber is detachable and attachable with the supply-side accommodation part or the drain-side accommodation part being closed by the corresponding dividing membrane, the pump body including a piston to move with activation of a motor and to displace the dividing membranes.

A hemodiafiltration system with a disposable pumping unit is disclosed. An example system includes a medical fluid pump actuator, a medical fluid heater, a blood filter and a disposable unit. The example disposable unit includes a medical fluid cassette portion including a medical fluid cassette housing configured to be operatively connected to the medical fluid pump actuator to pump medical fluid through the medical fluid cassette portion when the medical fluid cassette portion is in fluid communication with a medical fluid source. The example medical fluid cassette portion is also configured to be placed in fluid communication with the blood filter and with an extracorporeal circuit communicating with the blood filter, the fluid communication enabling hemodiafiltration to be performed. The example disposable unit also includes a heater bag configured to be placed in operable communication with the medical fluid heater and in fluid communication with the medical fluid cassette portion.

Hemodialysis and similar dialysis systems including a variety of systems and methods that make hemodialysis more efficient, easier, and/or more affordable, and include new fluid circuits for fluid flow in hemodialysis systems and a reciprocating diaphragm pump for pumping fluids. The reciprocating diaphragm pump includes a flexible diaphragm, a first rigid body having a curved pumping chamber wall, a second rigid body having an opposing curved control chamber wall. The diaphragm is interposed between the pumping chamber wall and the control chamber wall to define a pumping chamber and a control chamber. The diaphragm of the pump has a peripheral bead arranged to locate the diaphragm between the first rigid body and the second rigid body and a diaphragm body having a curved, semi-spheroid or domed shape. The diaphragm is pre-formed or molded so that during a delivery stroke of the pump, the elastic force of the diaphragm resisting its deployment into the pumping chamber prevents a peripheral portion of the diaphragm body from fully contacting the pumping chamber wall.