9449results about How to "Prevent backflow" patented technology

Containers for providing vapor phase reactant from liquid sources include bubbler designs and designs in which carrier gas flows over the liquid surface. Among the bubbler arrangements, a bypass conductance is provided to release excess pressure from the gas volume inside the container, or an enlarged bubbler tube is provided with a volume sufficient to accommodate all possible liquid backflow without having the liquid exit the container. Among the overflow designs, flow dividers provide a tortuous path for the gas to increase the time exposure of carrier gas packets to the evaporating liquid surface. The flow dividers can be microporous to encourage capillary action, thereby increasing the evaporating surface. The tortuous gas flow path can be separated from the liquid phase by a breathable semi-porous membrane that permits vapor phase reactant to pass through but prohibits liquid from passing in the other direction.

A method of dispensing a therapeutic fluid from a line includes providing an inlet line connectable to an upstream fluid source. The inlet line is in downstream fluid communication with a pumping chamber. The pumping chamber has a pump outlet. The method also includes actuating a force application assembly so as to restrict retrograde flow of fluid through the inlet while pressurizing the pumping chamber to urge flow through the pump outlet. A corresponding system employs the method.

A valve prosthesis device is disclosed suitable for implantation in body ducts. The device comprises a support stent, comprised of a deployable construction adapted to be initially crimped in a narrow configuration suitable for catheterization through the body duct to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location, and a valve assembly comprising a flexible conduit having an inlet end and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet. The support stent is provided with a plurality of longitudinally rigid support beams of fixed length. When flow is allowed to pass through the valve prosthesis device from the inlet to the outlet, the valve assembly is kept in an open position, whereas a reverse flow is prevented as the collapsible slack portions of the valve assembly collapse inwardly providing blockage to the reverse flow. The device is configured so that retrograde flow will be altered from laminar flow and directed towards the leaflets to effect closing.

A combined electrical and chemical stimulation lead is especially adapted for providing treatment to the spine and nervous system. The stimulation lead includes electrodes that may be selectively positioned along various portions of the stimulation lead in order to precisely direct electrical energy to ablate or electrically stimulate the target tissue. Embodiments of the stimulation lead include single or multiple lead elements. The multiple lead element embodiments can be selectively deployed to cover a targeted area. The lead may also includes central infusion passageway(s) or lumen(s) that communicates with various infusion ports spaced at selected locations along the lead to thereby direct the infusion of nutrients/chemicals to the target tissue. Some embodiments utilize a disposable sheath in combination with a reusable stimulation lead.

Methods and apparatus are provided for treating congestive heart by actively or passively enhancing perfusion to the renal arteries. A first embodiment comprises a specially configured balloon catheter and extracorporeal pump, wherein the pump operates in a “once-through” fashion or alternating volume displacement mode. In another embodiment the catheter includes a pair of balloons to isolate a region of the aorta, and a third balloon that directs flow into the renal arteries. In still further embodiments, a stent or cuff having a constricted region is deployed in or around the aorta, respectively, to create a backpressure upstream of the stent or cuff. Methods of enhancing renal perfusion also are provided.

A microdosing device comprises a pressure chamber which is at least partly delimited by a displacer, an actuating device for actuating the displacer, the volume of the pressure chamber being adapted to be changed by actuating the displacer, a media reservoir which is in fluid comunication with the pressure chamber via a first fluid line, and an outlet opening which is in fluid communication with the pressure chamber via a second fluid line. The microdosing device additionally comprises a means for detecting the respective position of the displacer and a control means which is connected to the actuating device and to the means for detecting the position of the displacer, said control means controlling the actuating device on the basis of the detected position of the displacer or on the basis of displacer positions detected during at least one preceding dosing cycle so as to cause the discharge of a defined volume of fluid from the outlet opening. The control means comprises means for controlling the actuating device with a signal of low edge steepness so as to cause the displacer to move from a first position to a predetermined second position, the second position of the displacer defining a larger volume of the pressure chamber than the first position. In addition, the control means comprises means for controlling the actuating device with a signal of high edge steepness so as to cause the displacer to move from the second position to the first position for discharging in this way a defined volume of fluid from the outlet opening.

A sheath attached to a guide wire, a tubular shaft member slidable on the guide wire and a filtering assembly constricted within the sheath are movable in a vessel to a position distal to a lesion in the direction of fluid flow. The filtering assembly may be formed from a plurality of angularly spaced splines and a mesh disposed on the splines having properties of passing fluid in the vessel while blocking the passage of emboli in the fluid. The splines may be provided with shape memory for expanding against the wall of the vessel when released from constriction by the sheath. The sheath may be moved relative to the filtering assembly and the support member to release the filter for expansion against the vessel wall. An interventional device can be used to treat the lesion. Any emboli released into the vessel as a result of the interventional treatment are blocked by the filter member while fluid is allowed to pass there through.

A beverage forming apparatus includes a storage tank, and a centrifugal pump having an inlet connected to the storage tank by a supply conduit. The centrifugal pump may include a priming vent located below a full level of the storage tank and permit air to vent as liquid primes the pump. A metering tank may have an inlet connected to the centrifugal pump by a pump conduit, and an outlet connected to a brew chamber that forms a beverage using liquid received from the metering tank. In one embodiment, a flow control valve, such as a check valve, may be provided in the pump conduit to allow flow from the pump to the metering tank, but resist flow in reverse. In another embodiment, a vent valve in the pump conduit may be arranged to vent at least a portion of the pump conduit, e.g., to ambient air pressure.

A raw material gas supply apparatus includes a liquid raw material gas supply source, a source tank storing liquid raw material, a gas distribution passage through which raw material gas comprising steam of the liquid raw material is supplied to a process chamber from the source tank, an automatic pressure regulator installed on an upstream side of the gas passage, wherein the automatic pressure regulator keeps supply pressure of the raw material gas at a set value, a supply gas switching valve installed on a downstream side of the gas passage, wherein this valve opens and closes the gas passage, an orifice provided on at least one of an inlet side or outlet side of the valve, wherein the orifice regulates flow rate of the raw material gas, and a constant temperature heating device heats the source tank, the gas passage, the valve and the orifice to a set temperature.

Apparatus for performing a transgastric procedure includes an elongated tubular main access device having the first lumen with open proximal end and a side opening distal end, and a second lumen with open ends. A balloon having a wall on the outside of the device surrounds the distal end and a fluid conduit extends along the device for inflating the balloon so that when the device is inserted into a patient's esophagus and the balloon is inflated, the portion of the esophagus opposite the distal end is isolated from the remainder of the esophagus. The apparatus may also include a side access unit having an elongated flexible coaxial inner and outer tubes having proximal and distal ends and being movable relatively in the axial direction. First seals are mounted to the distal end of the outer tube, and second seals are mounted to the distal end of the inner tube, an actuator adjacent to the proxable ends of the tubes move the tubes relatively so as to vary the axial spacing the first and second seals. Various methods for using the apparatus are also disclosed.

A Roots blower driven by a direct-current motor provided to a recirculation duct for connecting an exhaust duct and an intake duct to extract a part of exhaust gas of a diesel engine to recirculate to an intake side. Accordingly, even when a differential pressure between an exhaust side and the intake side, or even when a pressure on the intake side is higher than the exhaust side fluctuates, the exhaust gas flowing to the recirculation duct can be forcibly pumped by the Roots blower while appropriately controlling flow rate thereof, so that an optimum recirculation amount of exhaust gas in accordance with operation condition of the diesel engine can be recirculated to the intake side.

The present invention relates to apparatus and methods for preventing backflow into a beneficial agent dispensing osmotic delivery system.

The present application discloses devices that ablate human tissue. The device comprises a catheter with a shaft through which an ablative agent can travel, a liquid reservoir and a heating component, which may comprise a length of coiled tubing contained within a heating element, wherein activation of said heating element causes said coiled tubing to increase from a first temperature to a second temperature and wherein the increase causes a conversion of liquid within the coiled tubing to vapor, a reusable cord connecting the outlet of the reservoir to the inlet of the heating component, and a single use cord connecting a pressure-resistant inlet port of a vapor based ablation device to the outlet of the heating component.

The invention relates to a positive-pressure pneumatic conveying skid for an oilfield fracturing propping agent. The positive-pressure pneumatic conveying skid for the oilfield fracturing propping agent comprises a skid frame and is characterized in that a fan power-driven system, a gas channel and sand conveying system, a delivery tank assembly, movable feeding devices and an electric control system are arranged on the skid frame. The positive-pressure pneumatic conveying skid for the oilfield fracturing propping agent has the benefits as follows: the occupied area is small, the transportation is convenient, the operation environment and the operation safety are improved, and the efficiency of operation for conveying a material to a high storage tank is improved.