38results about How to "Reduce recirculation" patented technology

A foldable, intravascularly insertable blood pump (10) comprises a foldable, radially delivering impeller (20) accommodated in a foldable housing or envelope (24). Axially before and behind the impeller a clearance (60) is provided between the impeller (20) and the front and back walls (32, 62) of the housing (24), the clearance being at least 0.2 mm. Preferably, the space defined between adjacent blades (54) of the impeller (20) is open towards the front wall (32) of the housing (24).

A hemodialysis and vascular access system comprises a subcutaneous composite PTFE silastic arteriovenous fistula having an indwelling silastic venous end which is inserted percutaneously into a vein and a PTFE arterial end which is anastomosed to an artery. Access to a blood stream within the system is gained by direct puncture of needle(s) into a needle receiving site having a tubular passage within a metal or plastic frame and a silicone upper surface through which needle(s) are inserted. In an alternate embodiment of the invention, percutaneous access to a blood stream may be gained by placing needles directly into the system (i.e. into the PTFE arterial end). The invention also proposes an additional embodiment having an arterialized indwelling venous catheter where blood flows from an artery through a tube and a port into an arterial reservoir and is returned to a vein via a port and a venous outlet tube distinct and distant from the area where the blood from the artery enters the arterial reservoir. The site where blood is returned to the vein is not directly fixed to the venous wall but is free floating within the vein. This system provides a hemodialysis and venous access graft which has superior longevity and performance, is easier to implant and is much more user friendly.

Disclosed is an apparatus for oxygenating and controlling the temperature of blood in an extracorporeal circuit. The apparatus has an inlet and an outlet that is located radially outward from the inlet in order to define a flowpath through the apparatus. The apparatus comprises: a core that is substantially centrally located in the apparatus and to which blood from a patient can be supplied through the inlet; a heat exchanger comprising a plurality of heat transfer elements that are arranged around the core and between which blood from the core can move radially outward; and an oxygenator comprising a plurality of gas exchange elements that are arranged around the heat exchanger and between which blood from the heat exchanger can move radially outward before exiting the apparatus through the outlet.

A centrifugal pump includes plural pump stages, each comprising an impeller assembly, a stationary disc assembly and a diffuser assembly, all disposed about an impeller shaft. A floating impeller hub seal is supported by a diffuser assembly to minimize fluid recirculation. A thrust washer is disposed around the impeller shaft and is engageable with an impeller hub and the hub seal. A wear ring is secured to a disc assembly and engageable with a wear surface on the impeller.

A fuel injector for a gas turbine engine has an inlet fitting, a fuel nozzle, and a housing stem with a pair of fuel conduits fluidly interconnecting the nozzle and fitting. The fuel nozzle includes an annular secondary fuel passageway directing fuel from one fuel conduit to an annular discharge orifice at a discharge end of the nozzle. The secondary fuel passageway is defined between an outer, annular fuel conduit portion and a primary adapter. The primary adapter has an outer surface with a distinct, radially-outwardly-projecting annular shoulder to restrict flow through the secondary passageway and provide substantially uniform distribution of flow through the passageway downstream of the shoulder, for improved combustion and flame stability.

Described is an apparatus for oxygenating and controlling the temperature of blood in an extracorporeal circuit, the apparatus having an inlet and an outlet that is located radially outward from the inlet in order to define a flowpath through the apparatus, the apparatus comprising: a core in communication with the inlet such that blood from a patient can be supplied to the core, the core comprising a first element and a second element that interfit to define openings, wherein the elements and the openings together enhance flow of blood from the patient radially outward from the core; a heat exchanger that is arranged about the core and through which blood from the core can move radially outward; and an oxygenator that is arranged about the heat exchanger and through which blood from the heat exchanger can move radially outward before exiting the apparatus through the outlet.

A mass transfer column includes a feed device that is used to de-entrain liquid and more uniformly distribute vapor across a horizontal cross section of the column after a vapor or mixed phase stream has been directed into the column through a radially oriented feed nozzle. The feed device includes an annular passageway formed in the spacing between the column shell and an inner wall spaced inwardly from the shell. A deflector with oppositely directed deflecting surfaces is positioned at an inlet from the feed nozzle to the annular passageway and splits the vapor or mixed phase stream into two roughly equal streams that flow in opposite circumferential directions in the annular passageway. At least one pair of turning vanes is spaced on opposite sides of the deflecting surfaces in the annular passageway to create subpassages through which the vapor or mixed phase stream flows. The subpassages reduce the amount of vapor or mixed phase stream flow that impacts against the inner wall of the feed device at the inlet. The turning vanes unexpectedly reduce the pressure drop that occurs as the vapor or mixed phase stream is redirected from its radial entry direction to the circumferential direction in the annular passageway. By reducing the pressure drop, improvements in product yield and vapor distribution can be achieved.

A blood purification apparatus includes a blood circuit having arterial and venous blood circuits, a blood pump, a blood purifying device, an indicator applying device that applies a predetermined indicator to the blood flowing extracorporeally through the blood circuit, a detecting device that detects the indicator applied by the indicator applying device, an arithmetic device that calculates, based on the indicator detected by the detecting device, a recirculation rate, and a calculating device that calculates an ideal extracorporeally circulating blood flow that results in the recirculation rate being no more than a predetermined value when the recirculation rate calculated by the arithmetic device is greater than the predetermined value. The recirculation rate is a proportion of a recirculated blood flow, which is reintroduced to the patient from the venous blood circuit and directed again to the arterial blood circuit, relative to an extracorporeally circulating blood flow.

An implantable pump system is provided, suitable for use as a left ventricular assist device (LVAD) system, having an implantable pump, a battery, a controller, and a programmer. The implantable pump includes a flexible membrane coupled to an actuator assembly via a skirt that extends toward the inlet of the pump and curves to guide blood toward the outlet. The actuator assembly is magnetically engagable with electromagnetic coils, so that when the electromagnetic coils are energized, the actuator assembly causes wavelike undulations to propagate along the flexible membrane to propel blood from the inlet, across the skirt, and through the outlet of the implantable pump. The controller may be programmed by a programmer to operate at frequencies and duty cycles that mimic physiologic flow rates and pulsatility while operating in an efficient manner that avoids thrombus formation, hemolysis and/or platelet activation.

Tube heat exchanger comprising finned tubes, wherein the tubes extend in a certain axial direction and are provided with heat exchange fins. Each fin has a heat exchange surface surrounding a tube that extends in a certain radial direction in relation to the tube and which is relief structured to form grooves spaced apart from one another in said radial direction. The grooves of a fin have different dimensions that decrease on moving away from the tube in said radial direction so as to form a guide for a fluid around the tube.

Disclosed is an apparatus for oxygenating and controlling the temperature of blood in an extracorporeal circuit. The apparatus has an inlet and an outlet that is located radially outward from the inlet in order to define a flowpath through the apparatus. The apparatus comprises: at least one pump that is provided in a core of the apparatus and to which blood from a patient can be supplied through the inlet; a heat exchanger comprising a plurality of heat transfer elements that are arranged around the at least one pump and between which blood from the at least one pump can move radially outward; and an oxygenator comprising a plurality of gas exchange elements that are arranged around the heat exchanger and through which blood from the heat exchanger can move radially outward before exiting the apparatus through the outlet.

Various methods and systems are provided for separating particles within a gas flow traveling through a gas flow passage of an engine. In one embodiment, a particle separator includes a plurality of vanes positioned across a gas flow passage through which gas flow passes, the plurality of vanes angled with respect to a flow direction of the gas flow, and a particle trap for collecting separated particles, the particle trap disposed in the gas flow passage.

A hydraulic turbine is adapted to introduce oxygen into a water flowing through a water passageway of a turbine. The turbine has a circumferential chamber formed between a rotating band and a stationary discharge ring. The chamber has a gas admission aperture for receiving an oxygen containing gas into the chamber. A downstream end portion of the band has a plurality of spaced apart vanes providing chamber outlet passageways between the vanes and through the band. The vanes are configured to rotate with the band and to draw the oxygen containing gas and water from the chamber through the outlet passageways in the band and into the water passageway.

The present invention relates to a process for removing hydrocarbons comprising the steps of: (A) passing a stream of a solution into a separator wherein a liquid phase comprising polymer and a vapourphase coexist; (B) withdrawing a vapour stream and a concentrated solution stream from the separator; (C) passing at least a part of the vapour stream into a first fractionator; (D) withdrawing a first overhead stream and a first bottom stream from the first fractionator; (E) passing the first overhead stream to a second fractionator; (F) withdrawing a second overhead stream and a second bottom stream from the second fractionator; (G) passing the second overhead stream to a third fractionator; (H) withdrawing a third overhead stream and a third bottom stream from the third fractionator; characterised in that at least a part of the third bottom stream is withdrawn as a purge stream.