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 process fluid pump can include a pump chamber, an inlet valve, and an outlet valve. Diaphragm regions can define at least a portion of each of the pump chamber, the inlet valve, and the outlet valve. The diaphragm regions can each have an actuation region with a surface that is convexly shaped when the formed actuation region is in a natural unstressed first state, and each formed actuation region can be actuated by a motive fluid to transition to a second state in which the surface is non-convexly shaped.

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; and (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. 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 medical fluid delivery device includes 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; 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; and 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. The device further includes a first inlet valve diaphragm disposed between the first motive fluid inlet valve actuation area and the first process fluid inlet valve seat; and a first outlet valve diaphragm disposed between the first motive fluid outlet valve actuation area and the first process fluid outlet valve seat.

A positive displacement pump includes two fluid flow paths, two center sections with a common fluid valve, a changeover valve, and three fluid displacement members. Each center section contains a diaphragm shaft, and the two sections are separated by the third diaphragm. In low-pressure mode the pump operates as a typical positive displacement pump with pumping fluid supplied to one center section and the changeover valve allowing the fluid to freely circulate within the second center section. In high-pressure mode, the changeover valve is switched and the changeover valve allows the common fluid valve to supply pumping fluid to both center sections to drive the fluid displacement members therein, which generates a higher outlet fluid pressure.

An electronically controlled diaphragm pump system includes a pump housing with a drive gas chamber, a fluid chamber separated by a diaphragm, gas pressure means for providing a drive gas pressure in response to a control signal, and gas under-pressure means connected to a gas outlet port for providing a gas outlet under-pressure or sucking of gas in response to a control signal. The pump system has a displacement sensor and control circuitry connected to the displacement sensor for determining the displacement or position of the diaphragm and adapted or supplying the control signals to the gas pressure means and the gas under-pressure means.

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.

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 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.

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.