Abstract: A variable pressure drive peritoneal dialysis system has a pneumatic pressure system for purging and controlling a flow of dialysate through a disposable dialysate cassette of a disposable dialysate delivery set. The pneumatic pressure system has a variable-opening flow proportional valve for supplying air at selected profiled pressure or vacuum to a pneumatic interface. The disposable dialysate cassette has a diaphragm pump actuable by the profiled air pressure or vacuum to move dialysate to and from a patient via the disposable dialysate delivery set at a desired profiled dialysate pressure.

Abstract: An apparatus (31) and a method are disclosed for performing an operation upon multiple webs (51,53), including the feeding of multiple webs (51,53), the provision of a carrier (65) for assisting in moving the webs (51,53) along a predetermined path (83), the performance of an operation (69) upon the webs, the insertion of a carrier (65) between the webs (51,53), and the provision of a sealing device (71) for sealing the webs together to form a sealed portion (75) to cooperate with the carrier (65) for assisting in moving the webs (51,53). The carriers (65) are mounted on a conveyor (83) and each carrier (65) pushes against the sealed portion (75) to pull the webs (51,53), and the packages (41) formed therefrom in the direction of conveyor travel. The preferred carrier (65) has a shaped head on the end of a flat plastic blade.

Abstract: An apparatus (31) and a method are disclosed for temporarily separating multiple webs (51,53) while performing an operation (123,125,133) thereon, including the feeding of multiple webs (51,53), the provision of a retractable web separator (68) for temporarily separating the webs, the performance of an operation (123,125,133)) upon the webs, the provision of a gripping device (65) for gripping the webs and assisting in moving the webs (51,53) along a predetermined path (83), and the provision of a sealing device (71) for sealing the webs together to form a package seal (73). The retractable separators (68) are mounted on a conveyor (83) and each separator (68) in turn temporarily separates the webs (51,53), for insertion of a port (45), fitting or the like, whereupon the separator (68) may be retracted and the port (45) may be sealed into the packages (41) being manufactured. The preferred separator (68) has a shaped head (170) on the end of a reciprocating shaft (158).

Abstract: Pumping mechanisms for performing peritoneal dialysis and the like employ a pumping mechanism comprising a diaphragm that operate in response to applied fluid pressure. Flexible tubing is attached to the pumping mechanism for carrying liquid to and from the patient's peritoneal cavity. An actuating station for pumping mechanism receives the pumping mechanism and attached tubing. A pressure transfer element conveys fluid pressure to the diaphragm for moving liquid through the cassette. An occluder element contacts and crimps closed the tubing attached to the cassette. A first reservoir inflates with positive fluid pressure for contacting the pressure transfer element to hold it in operative contact against the diaphragm. A second reservoir inflates with positive fluid pressure for contacting the occluding element to hold it away from crimping contact with the tubing. At least one of the first and second reservoirs also transports fluid pressure to the pressure transfer element for conveyance to the diaphragm.

Abstract: Systems and methods for peritoneal dialysis establish flow communication between a patient's peritoneal cavity and a drain through a pump chamber having generally vertically spaced upper and lower regions andt a diaphragm. The systems and methods operate the pump chamber, with the upper and lower regions oriented generally vertically, by applying fluid pressure to the diaphragm. The systems and methods direct liquid to the patient's peritoneal cavity only from the lower region of the pump chamber. In this way, the improved systems and methods collect air in the upper region of the vertically oriented pump chamber, while isolating the patient's peritoneal cavity from air in the pump chamber.

Abstract: Peritoneal dialysis systems and methods move liquid using a pump chamber that is operated in response to pneumatic pressure variations applied by a pump actuator. The systems and methods periodically measure air pressures in the actuator and an associated reference air chamber and derive from these a measurement of liquid volume moved through the pump chamber. The systems and methods minimize derivation errors by compensating for temperature differences among the pump chamber; the pump actuator; and the reference chamber.

Abstract: A method of making a peelable tube assembly (76,80,84,88) having a plurality of adjacent tube portions (62) joined by intermittent breakable webs (72) of plastic allowing the individual portions (62) to be peeled from the tube assembly, including providing a plurality of plastic tube portions (62) each having a tube wall (66) defining a flow passage (70). The tube portions (62) are aligned adjacent to one another in a die assembly (12) having compression channels (30). Narrow confined flow chambers (32) are defined between adjacent portions (62) of the tube walls (66), and between the ends of the tube walls (66). The tube portions (62) are radially compressed without occluding the flow passage (70). Small compressed portions of the tube walls (66) proximate the flow chambers (32) are heated and plasticized.