A pumping cassette including a housing having at least two inlet fluid lines and at least two outlet fluid lines. At least one balancing pod within the housing and in fluid connection with the fluid paths. The balancing pod balances the flow of a first fluid and the flow of a second fluid such that the volume of the first fluid equals the volume of the second fluid. The balancing pod also includes a membrane that forms two balancing chambers. Also included in the cassette is at least two reciprocating pressure displacement membrane pumps. The pumps are within the housing and they pump the fluid from a fluid inlet to a fluid outlet line and pump the second fluid from a fluid inlet to a fluid outlet.

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 reciprocating positive displacement pump comprises a flexible diaphragm fluidically separating a pumping chamber from an actuation chamber. The membrane may include bumps or other features on the side of the membrane facing the pumping chamber that space at least a portion of the membrane away from the rigid chamber wall when the membrane is in a minimum-pumping-chamber volume position. Such structures may prevent pockets of fluid from being caught away from the inlet and outlet by keeping portions of the membrane spaced away from the rigid pumping chamber wall even when the pumping chamber volume is at a minimum.

A hemodialysis system includes a blood treatment machine, a blood pump housed by the blood treatment machine, a first dialysate pump housed by the blood treatment machine, a second dialysate pump housed by the blood treatment machine; and a fluid cassette including an upper portion and a lower portion. The fluid cassette further includes a blood pumping tube extending from the upper portion to the lower portion of the fluid cassette, a first dialysate pumping tube extending from the upper portion to the lower portion of the fluid cassette, and a second dialysate pumping tube extending from the upper portion to the lower portion of the fluid cassette.

A method for pumping and oxygenating blood includes receiving a flow of gas including oxygen into a gas inlet manifold via a gas inlet. The flow of gas is passed through the hollow fibers from the gas inlet manifold to a gas outlet manifold. The flow of gas is output from the gas outlet manifold via a gas outlet. An impeller is rotated to generate a flow of blood that flows over the hollow fibers. Oxygen from the flow of gas is transferred to the flow of blood through the hollow fibers. Carbon dioxide is transferred from the flow of blood to the flow of gas through the hollow fibers.

Medical fluid management assembly includes: a pneumatic manifold including multiple plates forming pneumatic passageways, a pneumatic valve chamber and a pneumatic pump chamber, the valve chamber in pneumatic communication with at least one passageway, the pump chamber in pneumatic communication with at least one passageway; and a fluid manifold including multiple fluid pathways, a fluid valve chamber in selective fluid communication with a fluid pump chamber and at least one fluid pathway, wherein (a) the pneumatic valve chamber and the fluid valve chamber are mated together to compress a membrane and (b) the pneumatic pump chamber and the fluid pump chamber are mated together to compress a membrane, wherein at least one of the pneumatic valve chamber or the pneumatic pump chamber extends from the at least one plate, or the fluid valve chamber or the fluid pump chamber extends from the fluid manifold to aid in compressing the membranes.

A method for priming a hemodialysis treatment includes: providing a disposable cassette including at least a portion of a dialysate circuit and at least a portion of a blood circuit; placing a dialyzer in fluid communication with the dialysate circuit via a to-dialyzer dialysate line and a from-dialyzer dialysate line; placing the dialyzer in fluid communication with the blood circuit via an arterial blood line and a venous blood line; placing a source of dialysis fluid in fluid communication with the dialyzer; priming the dialysate circuit with dialysis fluid from the source while both the to-dialyzer dialysate line and the from-dialyzer dialysate line are connected at their dialyzer ends to the dialyzer; and priming the blood circuit with dialysis fluid from the source by actuating at least one valve provided by the disposable cassette.

A renal failure therapy machine includes a blood cleaning filter, a dialysis fluid circuit including a balance chamber, the balance chamber including a fresh dialysis fluid compartment configured to send fresh dialysis fluid to the blood cleaning filter and a used dialysis fluid compartment configured to receive used dialysis fluid from the blood cleaning filter, a fresh dialysis fluid line in fluid communication with the fresh dialysis fluid compartment of the balance chamber and the blood cleaning filter, and a flow restrictor in fluid communication with the blood cleaning filter, the flow restrictor configured to cause fresh dialysis fluid delivered from the fresh dialysis fluid compartment, through the fresh dialysis fluid line, to the blood cleaning filter to be pressurized so that a first amount of the fresh dialysis fluid performs convective clearance and a second amount of the fresh dialysis fluid performs diffusive clearance.

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., surfactants or other fluids that may foam or otherwise be damaged or become unstable in the presence of turbulence).

A cassette integrated system. The cassette integrated system includes a mixing cassette, a balancing cassette, a middle cassette fluidly connected to the mixing cassette and the balancing cassette and at least one pod. The mixing cassette is fluidly connected to the middle cassette by at least one fluid line and the middle cassette is fluidly connected to the balancing cassette by at least one fluid line. The at least one pod is connected to at least two of the cassettes wherein the pod is located in an area between the cassettes.