3128 results about "Pump chamber" patented technology

An implantable pump system includes: (1) an implantable pump having separate chambers or reservoirs, at least one of which is coupled to the pump so as to allow a programmable rate of delivery of the medication stored in the pump chamber or reservoir, the other chambers or reservoirs of which are at least capable of delivery of a bolus via a pressurized, and potentially independently programmable chamber or pumping mechanism; (2) a patient controller that enables the actuation of the pump so as to administer a bolus or programmed rate of the first, second, third, . . . or nth medication contained in the independent chambers or reservoirs coupled to the pump; and (3) a catheter having two or more reservoir-specific inlet ports directed into respective lumens of the catheter. In one embodiment, the distal tips of the respective lumens may be directed to different sites within the patient's body, thereby allowing site specific and independent delivery of the medications stored in the respective pump chambers or reservoirs to be administered to different body sites at independently controlled times and rates. In another embodiment, the distal tips of the respective lumens are directed, more or less, to the same body site or tissue region, thereby providing for the independent delivery of multiple medications to the same regions at independently controlled times and rates.

A rotary blood pump includes a casing defining a pumping chamber. The pumping chamber has a blood inlet and a tangential blood outlet. One or more motor stators are provided outside of the pumping chamber. A rotatable impeller is within the pumping chamber and is adapted to cause blood entering the pumping chamber to move to the blood outlet. The impeller has one or more magnetic regions. The impeller is radially constrained in rotation by magnetic coupling to one or more motor stators and is axially constrained in rotation by one or more hydrodynamic thrust bearing surfaces on the impeller.

Improved integrity test, priming sequence and bag height detection tests, apparatuses and methods for a medical fluid delivery system are provided. The integrity test includes a plurality of air pressure decay tests, using positive and negative pressure. The priming sequence includes pumping fluid through a portion of a patient line to be primed to overcome air in the line and other potential obstacles. The head height test measures a pressure build-up or drop-off within a pump chamber of a membrane pump. The measured pressure corresponds to a head height between a fluid supply and the pump or between the pump and a fluid drain. A determination is made whether the corresponding head height is acceptable.

A rotary blood pump may include one or more motor stators overlying exterior surfaces of a wall defining a pumping chamber. A rotatable impeller within the pumping chamber may have a hydrodynamic thrust bearing surface adapted to constrain a position of the impeller along an axis of rotation relative to the wall when the impeller is rotating about the axis of rotation. The impeller position may then be constrained without requiring a constant polarity magnetic force to be applied in the axial direction from a fixed position of the housing.

A fluid handling cassette (24), such as that useable with an APD cycler device or other infusion apparatus, may include a generally planar body having at least one pump chamber (181) formed as a depression in a first side of the body and a plurality of flowpaths for fluid that includes a channel. A patient line port may be arranged for connection to a patient line (34) and be in fluid communication with the at least one pump chamber via at least one flowpath, and an optional membrane (15) may be attached to the first side of the body over the at least one pump chamber. In one embodiment, the membrane may have a pump chamber portion (151) with an unstressed shape that generally conforms to the pump chamber depression in the body and is arranged to be movable for movement of fluid in the useable space of the pump chamber. One or more spacers (50) may be provided in the pump chamber to prevent a pump membrane from contacting an inner wall of the pump chamber. Patient, drain (28) and / or heater bag lines (26) may be positioned to be separately occludable in relation to one or more solution lines (30) that are connectable to the cassette.

A medical pump with an improved continuity low flow delivery system and method for use with a pumping chamber, for example in a cassette, is disclosed. The pump includes a pump drive for exerting a force on the pumping chamber and a sensor for sensing the force / pressure exerted by the pump drive on the pumping chamber. The pump drive position sensor senses the position of the pump drive. The medical pump also includes a processing unit and a memory having a programming code adapted to calculate the rate of change of the sensed force / pressure values and determine whether the rate of change of the sensed force / pressure values meets a rate of change threshold. Once the rate of change threshold is met, the programming code is adapted to calculate a remaining pump drive travel value for determining how much farther the pump drive should travel before the end of an effective pump cycle. The programming code is further adapted to trigger one or more signals to drive the pump drive for the remainder of the effective pump cycle using the remaining pump drive travel value.

A molten metal pump including a pump base with an inlet and outlet, a mixing impeller chamber for mixing gas and molten metal, a pumping impeller chamber for pumping molten metal. First and second impeller members supported by a shaft are adapted to rotate in mixing and pumping chambers respectively. The impeller members may be integrally formed of a single impeller or separate impellers on one or more shafts. A gas passageway extends from a gas source to the mixing chamber in the base. A gas dispersement pump includes a base with an impeller chamber and inlet and an outlet. An impeller is mounted to a shaft and adapted to be rotated in the impeller chamber. A gas passageway extends from a gas source to a gas outlet proximate to the impeller chamber. A gas dispersement member of porous refractory material is adapted to disperse gas from the gas passageway. In a gas dispersement and gas / molten metal mixing pump, the dispersement member disperses the gas stream entering the mixing chamber where the gas is mixed with molten metal. Molten metal is pumped in the pumping chamber. A gas / molten metal mixture is discharged from the mixing chamber and molten metal is discharged from the pumping chamber.

A surgical handpiece having at least two lumens or tubes mounted to a body. At least one tube is used for aspiration and at least one other tube is used to inject heated surgical fluid for liquefying a cataractous lens. A portion of the second tube is enlarged to form a pumping chamber. The pumping chamber works by boiling a small volume of the surgical fluid. As the fluid boils, it expands rapidly, thereby propelling the liquid downstream of the pumping chamber out of the second tube. The pumping chamber may use a pair of electrodes.

Systems and related methods pump fluid through a pump. The pump comprises a pump chamber, which is responsive to applied pressures to convey fluid. The systems and methods place an electrode in electrical conductive contact with fluid in the pump chamber which, in use, is coupled to an electrical source. The electrode generates an electrical field in the pump chamber that varies according volume of fluid in the pump chamber. The systems and methods register variations in the electrical field as fluid is conveyed through the pump chamber.

A device for use in a molten metal pump helps alleviate jams between a rotating rotor and stationary inlet. The device includes an inlet structure including one or more openings and a displacement structure that preferably includes one or more rotor blades. The inlet structure and displacement structure are connected to one another (preferably, but not necessarily, as a unitary piece), thus enabling them both to rotate. A pump including the device is also enclosed. The invention further includes a bearing surface for an impeller or for a device according to the invention, wherein the bearing surface includes grooves that help reduce molten metal build up between the bearing surface of the impeller or device and the bearing surface of a pump chamber.