Abstract: Peritoneal dialysis systems and methods apply fluid pressure to move liquid. The systems and methods can emulate either a fixed head height condition or different head height conditions, independent of the actual head height differential between the patient's peritoneal cavity and the external liquid source or destination. The systems and methods can also switch between low-relative pressure flow mode when considerations of patient comfort and safety predominate and a high-relative pressure flow mode when considerations of processing speed predominate.

Abstract: A non-invasive technique and system is provided for measuring flow of liquid driven by a flexible diaphragm of a membrane pump (18). Flow, pressure and/or temperature of a gas, such as air, used to drive the pump (18) is continuously monitored. Instantaneous volume of liquid being pulled into or out of a chamber of the pump (18) can be calculated from measured values of the gas used to drive the pump (18). Sensors (10, 12 and/or 14) are used to measure values relating to the gas. The sensed parameters are concurrently monitored and continuously determine the amount of gas flowing to and from the diaphragm of the membrane pump (18) utilized to move liquid within a liquid pathway. The measurements may then be used to calculate the instantaneous flow rate of the liquid.

Abstract: A connector having an occluder which transposes between a first position and a second position is provided for maintaining a sterile environment during connection and disconnection of fluid communication between a container and a fluid line. The occluder is in the form of a spherical ball integrally formed with a length of tubing. The occluder has a diameter slightly larger than an end of the connector such that the occluder rolls into the end upon disconnecting from the system. An interface may be provided to receive a single connector or a pair of connectors to assist in fluid control between the container and the fluid line.

Abstract: A method and device for stabilizing and storing bicarbonate solutions is provided. In an embodiment, a device is provided having a container and carbon-dioxide generating substances that include a solid material which upon contact with water generates carbon-dioxide gas. The device may be packaged together with the bicarbonate or in a separate overpouch. The present invention also provides a method for the stabilization of bicarbonate solutions utilizing a means that generates high pressure carbon dioxide.

Abstract: The present invention provides an improved coextruded medical grade port tubing. The medical grade port tubing provides characteristics that are desirable in the medical industry and therefore can be used as a medical port tubing in, for example, renal therapy or blood donor tubes. To this end, the present invention provides a non-PVC coextruded medical grade port tubing including: an outer layer comprising a blend of polypropylene copolymer and styrene-ethylene-butylene-styrene copolymer; a tie layer; and a core layer including a blend of polyamide and ethylene vinyl acetate.

Abstract: Peritoneal dialysis systems apply fluid pressure to move liquid. The systems can emulate either a fixed head height condition or different head height conditions, independent of the actual head height differential between the patient's peritoneal cavity and the external liquid source or destination. The systems can also switch between low-relative pressure flow mode when considerations of patient comfort and safety predominate and a high-relative pressure flow mode when considerations of processing speed predominate.

Abstract: A system for processing a product with a solvent containing volatile constituents, the system including a pressure chamber for receiving the product, a vacuum pump for evacuating the chamber, a solvent recirculating system for admitting the solvent at a predetermined pressure into the chamber, the solvent recirculating system including a heater for maintaining the temperature of the chamber at the saturation temperature of the solvent, gas liquid separator for separating the gas and liquid components of the solvent discharged from the chamber, a first closed loop system connected to the separator to return the gas constituent to the chamber and a second closed loop system connected to the separator to return the liquid component to the chamber.

Abstract: An automatic means and method for preventing and/or treating hypotension in hemodialysis patients. To this end, a system is provided wherein the patient or healthcare practitioner can cause the hemodialysis machine to automatically deliver sodium to the patient through the dialysate so as to increase blood and extracellular osmolarity, increase blood volume from vascular refilling, and raise blood pressure. This would thereby alleviate any clinical symptoms caused by hypotension during hemodialysis.

Abstract: An apparatus for proportioning solutions from at least first and second constituent solutions connected to separate inlet ports of the apparatus first detects which constituent solution is being supplied to which port and then properly proportions the finished solution from the constituent solutions irrespective of which constituent solution is connected to which inlet port.

Abstract: A vacuum air lock assembly for transferring an article into an enclosure for treating the article with a solvent, the enclosure including a door for admitting the article into or out of the enclosure, the assembly including a chamber mounted on the enclosure and having an outer door, the chamber being sealed to the enclosure for transferring the article from the chamber through the enclosure door into the enclosure, a vacuum pump for drawing a vacuum in the chamber and discharging the air to atmosphere, the chamber being connected to the enclosure to break the vacuum in the chamber with solvent vapor from the enclosure, the article is transferred into the enclosure through the enclosure door for treatment and returned to the chamber after treatment, and the solvent vapor in the chamber is returned to the enclosure chamber through the vacuum pump and the vacuum in the chamber is broken to atmosphere.

Abstract: Systems for performing peritoneal dialysis allow the user to chose from an array of peritoneal dialysis modalities and adjust one or more individual therapy parameters within a selected modality. Still, the systems assure that the selected modality and therapy parameters satisfy preselected composite therapy criteria.

Abstract: A method is provided for cleaning an article with a solvent having a boiling point such that the solvent is a gas at room temperature and one atmosphere pressure. Such a method includes the steps of disposing the article in a chamber, introducing the solvent into the chamber so that the solvent contacts the article, pressurizing the chamber so that the solvent is in a liquid state and removes contaminants from the article, purging the chamber to remove the solvent, and removing the treated article from the chamber. Such a system permits the use of liquids having boiling points lower than room temperature, such as certain C.sub.1 -C.sub.4 halocarbons, which liquids have not previously been used as cleaning solvents.

Abstract: A one-piece unitary frangible spike connector for insertion into solution containers includes a spike body formed with a closure on one end thereof and a tubing receptacle on the other end thereof. An internal conduit extends from the tubing receptacle through the spike body partially into the closure. The frangible spike connector is broken apart along a reduced diameter portion tapered or formed at an angle to form a spike connected to the conduit on the spike body when the closure is broken off the spike body.

Abstract: The invention employs dual-skinned membranes useful as one way or rectifying membranes which reduce back filtration of solute molecules in dialysis and which improve nutrient supply and product recovery in membrane bioreactors. The membranes are dual-skinned polymeric materials preferably in the form of hollow fibers. The membranes have sieving coefficient characteristics different for flow of liquids in one direction from that in the opposite direction. Improved dialysis devices are formed by using bundles of the hollow fiber membranes as a dialysis means having rectifying properties. Improved bioreactors are formed by using bundles of hollow fiber as a growth vessel having rectifying properties.

Abstract: A system for processing a product with a solvent containing volatile constituents, the system including a pressure chamber for receiving the product, a vacuum pump for evacuating the chamber, a solvent recirculating system for admitting the solvent at a predetermined pressure into the chamber, the solvent recirculating system including a heater for maintaining the temperature of the chamber at the saturation temperature of the solvent, gas liquid separator for separating the gas and liquid components of the solvent discharged from the chamber, a first closed loop system connected to the separator to return the gas constituent to the chamber and a second closed loop system connected to the separator to return the liquid component to the chamber.

Abstract: An emission control system for a fluid composition comprised of volatile constituents used to clean a hollow fiber filter or capillary flow dialyzer including a housing having a chamber for receiving the dialyzer, a control system is used for establishing a desired environment in the chamber, the dialyzer and the fibers, a separator operatively associated with the chamber for separating gas and liquid components of the fluid composition, a stripper connected to the separator for fractionating lower boiling point volatiles from the gas to return the higher boiling point volatiles to the fluid phase and yield a stripped or solvent humidified gas and a delivery system for routing the stripped gas to the chamber dialyzer and fibers as a drying agent.

Abstract: A valveless positive displacement pump including a closed end cylinder having two fluid inlet and outlet ports adjacent the closed end. A piston reciprocably and rotatably driven in the cylinder and including a reduced area portion on one free end which communicates cyclically with the inlet and outlet ports to pump fluid through the positive displacement pump. The piston reduced area is a reduced radius portion to minimize air bubble buildup and to minimize fluid volume at the end of the piston stroke. The piston also has a gland area formed in the piston which cyclically communicates with a pair of ports to clean the piston and cylinder and prevent the buildup of solids. The piston and cylinder can be formed from a hard ceramic material for accuracy and wear resistance. The cylinder is closed by a resilient end cap to relieve pressures caused by piston movement when the inlet and outlet ports are closed.

Abstract: A method of stabilizing chlorofluorocarbon compositions thereby is provided. The stabilized composition comprises a chlorofluorocarbon and a sufficient amount of an epoxidized, generally high molecular weight stabilizer having an oxirane content sufficient to effectively stabilize the chlorofluorocarbon. The stabilizer is preferably an epoxidized oil having a molecular weight in the range of about 300 to about 1,500 and an oxirane content of at least about 4%. The method includes the step of adding a sufficient amount of such a stabilizer to the chloroflurocarbon composition. The chlorofluorocarbon composition typically comprises chlorofluoromethane, chlorofluoroethane, mixtures thereof or a chlorofluorocarbon-alcohol azeotropic solution. Also provided is an improved continuous dialyzer cleaning method utilizing the stabilized chlorofluorocarbon composition.

Abstract: A method for maintaining a flammable solvent in a nonflammable environment involves covering the flammable solvent with a nonflammable vapor blanket provided by a nonflammable solvent, such that vapors from the flammable and nonflammable solvents form a nonflammable gaseous mixture in the blanket. Such a method is used in removal of both oil-based and polar contaminants to control the flammability potential of an alcohol solvent. An apparatus for cleaning articles using fluorocarbon and alcohol solvents includes a chamber having a plurality of compartments for containing the solvents and a bounded vapor space. At least one of the compartments contains liquid fluorocarbon and at least one other will contain liquid alcohol. The solvents voltalize into the bounded vapor space to provide a nonflammable vapor blanket over the alcohol-containing compartment.