Provided is a pump system including: a pump configured to send out a fluid in response to application of a voltage, an ejection amount of the fluid increasing or decreasing in accordance with the voltage; a flow meter configured to measure a flow rate of the fluid sent out from the pump; and a control unit connected to the pump and the flow meter, and configured to control the voltage that is applied to the pump according to the flow rate measured by the flow meter.

A drive device is provided comprising a working pump, the working pump connected to a membrane fluid pump, and the working pump having a working piston able to oscillate axially between two reversal points for contracting and expanding a working chamber, and a control unit for controlling a movement of the working piston between the two reversal points. The controlled movement of the working piston comprises three temporally successive phases, in a first phase the working piston is accelerated to a speed that is greater than a speed at the end of the first phase, in a second phase the working piston is moved such that a specified speed of the working piston, a specified relative pressure in the working chamber, or a specified force of the working piston is substantially kept constant, and in a third phase the working piston is moved at a negative acceleration.

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).

Described is a large volume parenteral (LVP) infusion device system including a cassette and a pump. The system can include means for sensing pressure in a pump having a symmetric or matched, parallel dual chamber pumping mechanism and an attached cassette. The system can include a cassette having dual pumping chambers and a distal fitment, the distal fitment having an outlet port configured for attachment to tubing for infusion administration and being disposed on a distal end of the cassette, the distal fitment further including opposing cutouts. The system can also an air in line sensor, the AIL sensor configured to bracket the distal fitment at the position of the cutout when the cassette is loaded on the pump. The cassette can be mechanically coupled to the pump. The cassette can include a user actionable flow stop. The system can be configured for cassette misload protection.

Provided is a tube pump including: a housing unit that has an inner peripheral surface, which is formed in an arc shape around an axis, along which a tube with flexibility is disposed, and that is opened toward one end side along the axis; a pair of roller units that are accommodated in the housing unit and rotate about the axis in a state in which the tube is blocked; a pair of drive units that cause each of the pair of roller units to rotate about the axis in the same direction; and a cover member that is disposed in the housing unit such that the cover member covers the pair of roller units and provides an annular opening region into which the tube is able to be inserted toward the inner peripheral surface.

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).

A tube pump system is provided, which includes a pair of roller units which are rotated around the axis line from a contact position to a separate position in a state where the pair of roller units compress the tube, a pair of drive units which rotate the pair of roller units respectively, and a control unit which controls each of the pair of drive units, wherein the control unit controls each of the pair of drive units such that, when one of the pair of roller units passes the separate position, an angular velocity of the other of the pair of roller units toward the separate position is gradually decreased.

A method for surveillance of an air operated diaphragm pump is provided whereby initially an accelerometer with at least 3 orthogonal accelerometer measuring directions is attached to an air operated diaphragm pump or to a structure directly connected with an air operated diaphragm pump; agitation level of the accelerometer at a frequency rate above a predefined pulse rate of the air operated diaphragm pump is registered, and a base line noise level of the accelerometer agitation level during a period of no pump action is measured and stored, and a pulse rate of the air operated diaphragm pump is determined as the most significant frequency of pulses out of an entire power spectrum calculated from the accelerometer readings, and lastly the most significant frequency of pulses and the duration of registered pulse signals is determined and stored.

A mini air pump which includes a diaphragm, a bladder base provided with penetrating bladder holes and air inlet channels, a pump body having a valve seat and a pump cover, an air inlet valve, an air outlet valve, a relief valve and a preload member is revealed. The valve seat is stacked over the diaphragm. An exhaust chamber and a spring chamber are constructed by the valve seat and the pump cover. The valve seat has exhaust channels communicating with the bladder cavity. A communicating return channel is constructed by the diaphragm, the bladder base and the valve seat. The return channel is communicating with the air inlet channel but not communicating with the spring chamber. A spring of the preload member applies a preload to the relief valve. Thereby the relief valve acts more accurately and the mini air pump is more stable in use.

A method for designing a compressor operable to compress a refrigerant. The method may include determining operating conditions for the compressor. The method may also include weighting the operating conditions. The method further include determining a compressor volume ratio based on the refrigerant and the weighted operating conditions.