Devices and methods for operating a diaphragm compressor. Embodiments of the present disclosure comprise an oil piston being driven to pressurize work oil against the diaphragm of the compressor. In embodiments, an injection pump provides a supplemental flow of work oil in the region of pressurized fluid, and such pump may be part of an actively controlled system. In embodiments, a pressure relief valve vents an overpump flow of work oil, and such valve may be variable. Embodiments provide feedback and control mechanisms, including control of the injection pump and the relief valve.

A medical fluid pumping system includes a medical fluid pump for pumping a process fluid, the medical fluid pump including a first pump chamber, a first inlet valve chamber including a first inlet valve diaphragm, a first outlet valve chamber, a second pump chamber, a second inlet valve chamber including a second inlet valve diaphragm, and a second outlet valve chamber; and a medical fluid chassis operable with the medical fluid pump, the medical fluid chassis including a motive fluid source providing motive fluid at a motive fluid pressure, and wherein the first and second inlet valve diaphragms are configured to actuate from an open to a closed position at a pressure less than the motive fluid pressure to mitigate process fluid backflow through the first and second inlet valves.

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 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; and (iv) a venous blood line extending downstream from the dialyzer. The system also includes 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 positive displacement pump includes a housing surrounding a drive chamber and a diaphragm compartment. A drive element is inside the drive chamber. A diaphragm is inside the diaphragm compartment and divides the diaphragm compartment into a fluid chamber and a cavity. A shaft connects the drive element and the diaphragm. A breather valve is fluidically connected to the cavity and is configured to allow air to exit the cavity. The cavity is fluidically disconnected from the drive chamber.

The present disclosure provides apparatuses and methods that integrate sensors into bioprocessing systems and, advantageously, do not require significant re-engineering of these systems. The disclosure describes an assembly for alternating tangential flow filtration. The assembly also includes a sensor inserted into the first hemisphere of the pump housing via the port. In various embodiments, the port comprises a tri-clover connector, and the sensor is optionally inserted into the port through a plug sized to substantially occlude the port and to place the sensor in contact with a fluid in the pump housing.

Devices that include a liquid chamber including at least two ports, wherein the opening of a first port is larger than the opening of a second port, an air chamber including at least one port, and a membrane located between the liquid chamber and the air chamber, and a pressure sensor coupled to the port in the air chamber are provided. Systems including the disclosed devices are also provided. The systems include liquid in the liquid chamber of the device. Methods of using the devices and systems include measuring one or more properties of a liquid by flowing the liquid through the liquid chamber of the system and measuring the pressure produced due to the difference in size of the ports in the liquid chamber.

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.

A surge suppressor includes a boost mechanism configured to balance pressures between a working fluid and a process fluid. The boost mechanism includes a boost member that is acted on by a charge pressure of the working fluid. A shaft extends from the boost member to a pressure control member bounding the process fluid and acting on the process fluid. The boost member can have a larger effective area than the pressure control member to provide a pressure multiplication between the charge pressure and the process fluid pressure. In addition, pressure control valves are mounted to an air housing and actuated open by the boost mechanism. Actuating one of the pressure control valves open increases the charge pressure. Actuating the other pressure control valve open decreases the charge pressure.

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).