Embodiments of the present invention relate generally to certain types of reciprocating positive-displacement pumps (which may be referred to hereinafter as pods, pump pods, or pod pumps) used to pump fluids, such as a biological fluid (e.g., blood or peritoneal fluid), a therapeutic fluid (e.g., a medication solution), or a surfactant fluid. The pumps may be configured specifically to impart low shear forces and low turbulence on the fluid as the fluid is pumped from an inlet to an outlet. Such pumps may be particularly useful in pumping fluids that may be damaged by such shear forces (e.g., blood, and particularly heated blood, which is prone to hemolysis) or turbulence (e.g., surfectants or other fluids that may foam or otherwise be damaged or become unstable in the presence of turbulence).

Foam-based pneumatic actuators can be formed in a state of mechanical compression prior to actuation. An actuator includes an elastomeric foam; a coating disposed on the elastomeric foam; and an elastomer seal disposed on the coating. The coating constrains the elastomeric foam and can be configured to break or fracture when the elastomeric foam inflates. The elastomer seal can be configured to be impermeable to the actuating fluid. Such a foam actuator can be used in a cardiac compression device. These foam actuators possess increased actuation deformation and an actuation exerted force for a given inflation pressure. A large deformation can be provided from materials having low ultimate strains.

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 blood pump. The blood pump is configured to pump blood to a dialyzer of a hemodialysis apparatus and comprises a pneumatically actuated or controlled reciprocating diaphragm pump. The diaphragm of the pump comprises a flexible membrane formed or molded to conform to a curved inner wall of a pumping chamber or control chamber of the pump, and the diaphragm is pre-formed or molded to have a control side taking a convex shape, so that any elastic tension on the diaphragm is minimized when fully extended into a control chamber of the pump.

A modular assembly for a portable hemodialysis system may include a dialysis unit, e.g., that contains suitable components for performing hemodialysis, such as a dialyzer, one or more pumps to circulate blood through the dialyzer, a source of dialysate, and one or more pumps to circulate the dialysate through the dialyzer, and a power unit having a housing that contains suitable components for providing operating power to the pumps of the dialysis unit. The power unit may be selectively connected to the dialysis unit and provide power (e.g., pneumatic power in the form of pressure and/or vacuum) to the dialysis unit for the pumps when connected to the dialysis unit, but may be incapable of providing power to the dialysis unit when disconnected from the dialysis unit. The dialysis unit and the power unit are sized and weighted to each be carried by hand by a human.

A hemodialysis system configured to purge air from a blood circuit comprising: a dialyzer; a dialysis fluid circuit operable with the dialyzer via dialysis fluid inlet and outlet lines; the blood circuit operable with the dialyzer and including an arterial line, a venous line, a blood pump operable with the arterial line upstream of the dialyzer, and a physiologically acceptable fluid source in fluid communication with the arterial line upstream of the blood pump; and an air purging scheme wherein, with the dialysis fluid inlet and outlet lines connected to the dialyzer, air is purged using dialysis fluid or other physiologically acceptable fluid pumped by at least one of the fresh or used dialysis fluid pumps from the dialysis fluid circuit, through the dialyzer, into the blood circuit, in combination with dialysis fluid or other physiologically acceptable fluid from the source introduced directly into the blood circuit.

A pump cassette is disclosed. The pump cassette includes a housing having at least, one fluid inlet line and at least one fluid outlet line. The cassette also includes at least one reciprocating pressure displacement membrane pump within the housing. The pressure pump pumps a fluid from the fluid inlet line to the fluid outlet line. A hollow spike is also included on the housing as well as at least one metering pump The metering pump is fluidly connected to the hollow spike on the housing and to a metering pump fluid line. The metering pump fluid line is fluidly connected to the fluid outlet line.

A medical fluid delivery device includes (i) a process fluid body including first and second sides defining a first process fluid inlet valve seat and a first process fluid outlet valve seat and a second process fluid inlet valve seat and a second process fluid outlet valve seat; (ii) a first motive fluid plate defining a first aligned motive fluid inlet valve actuation area and a first aligned motive fluid outlet valve actuation area; (iii) a second motive fluid plate defining a second aligned motive fluid inlet valve actuation area and a second aligned motive fluid outlet valve actuation area; (iv) a first inlet valve diaphragm disposed between the first motive fluid inlet valve actuation area and the first process fluid inlet valve seat; and (v) a first outlet valve diaphragm disposed between the first motive fluid outlet valve actuation area and the first process fluid outlet valve seat.

A medical fluid pumping system includes (i) a medical fluid pump including a pump chamber, inlet and outlet valve chambers in fluid communication with the pump chamber, the pump chamber associated with a pumping chamber motive fluid connection, the inlet valve chamber associated with an inlet valve motive fluid connection, and the outlet valve chamber associated with an outlet valve motive fluid connection; (ii) a medical fluid chassis including a motive fluid source, and a first motive fluid connecting structure, a second motive fluid connecting structure, a third motive fluid connecting structure; and (iv) wherein the pumping chamber motive fluid connection, the inlet valve motive fluid connection, and the outlet valve motive fluid connection are translated simultaneously to mate respectively with the first motive fluid connecting structure, the second motive fluid connecting structure, and the third motive fluid connecting structure for fluid communication with the motive fluid source.

A blood treatment system includes (i) a blood pump including a first blood pump chamber operable with a first inlet valve and a first outlet valve, and a second blood pump chamber operable with a second inlet valve and a second outlet valve; (ii) an arterial blood line; (iii) a dialyzer placed in fluid communication with the arterial blood line, wherein the blood pump is provided along the arterial blood line upstream of the dialyzer; (iv) a venous blood line extending downstream from the dialyzer; and (v) a processor configured to sequence the first and second blood pump chambers so as to achieve a pulsatile pattern of filling the first and second blood pump chambers and an at least substantially constant pattern of discharging blood from the first and second blood pump chambers to the dialyzer.

A ventricular assist device includes a rigid, elongated shaft; an anchor assembly attached to a first end of the elongated shaft; a brace attached to a second end of the elongated shaft, the brace having a surface facing the anchor assembly; and one or more actuators attached to the brace and disposed adjacent the first surface of the brace.