Abstract: A dialysis apparatus includes a series blood circuit that extends from a single needle through a hemodialyzer and back to the needle. Extending from this circuit is a single ended arm that includes a pump and a blood accumulation chamber. The pump is cyclically operated in opposite directions (in cooperation with associated valves) to alternately withdraw blood from the patient to the chamber and to expel blood from the chamber back to the patient. During one of these operations, blood flows through the dialyzer. By hydraulically isolating the pump and expansion chamber from the series blood circuit, the apparatus avoids large pressure swings and the attendant ultrafiltration that can occur with other single needle systems.

Abstract: An improved hollow fiber bioreactor system is disclosed that includes an arrangement for removing the plasticizer that is typically found within the hollow fibers of hollow fiber cartridges so as to prevent this material from contaminating the nutrient fluid. The plasticizer is removed without jeopardizing sterility of the bioreactor.

Abstract: An improved bioreactor system for culturing cell products is disclosed in which novel system components are employed to reduce cost and increase reliability. The system includes a simple in-line heater for heating the nutrient fluid, thereby obviating the need for an expensive incubator. Gas bubbles formed during the heating of the nutrient fluid are removed by a novel gas trap that requires no operator intervention. A humidifier humidifies an aerating gas before it is passed through an oxygenator, thereby preventing water within the nutrient fluid from evaporating, with a consequent increase in nutrient fluid concentration. The operation of the humidifier is efficiently combined with that of a nutrient fluid heat exchanger so that a pump is not required to circulate the heat exchanger water bath. The system further includes a valve and pump arrangement whereby fresh nutrient fluid can periodically be introduced and spent nutrient fluid periodically drained without operator intervention.

Abstract: A novel class of bioreactor apparatuses are disclosed which offer improved performance over prior art designs. The apparatuses circulate nutrient fluid through a bioreactor device, such as a hollow fiber bioreactor cartridge, which is used to culture a colony of cells. The nutrient fluid is refreshed by the controlled addition of fresh fluid and the controlled removal of used fluid through a sterile infusion/extraction device. Cellular by-product yield is enhanced by periodically alternating the direction of nutrient fluid through the bioreactor and by periodically circulating the harvest fluid through the extracapillary region of the bioreactor cartridge.

Abstract: An open, volumetrically regulated patient fluid management system and method are disclosed. Fresh fluid is metered into a patient fluid exchange unit by a first metering device and spent fluid is drawn out by a pump. A back pressure regulator is provided across the pump to maintain its output pressure at a constant value. To the output of the pump are connected a second metering device and an open drain circuit. The second metering device meters out of the patient fluid exchange unit a predetermined quantity of spent fluid. The open drain circuit drains any fluid pumped by the pump, but not removed by the second metering device, to a drain open to atmospheric pressure. When the dialysis unit is deenergized, fluid in the dialyzer returns rapidly to atmospheric pressure by virtue of the open path through the open drain circuit, pump and back pressure regulator to the dialyzer.

Abstract: A method of hemodialytic ultrafiltration in a device utilizing a dialysate flow path, a hemodialyzer, a first receptacle and a second receptacle comprises supplying fresh dialysate to the first receptacle. Spent dialysate is withdrawn from the second receptacle at substantially the same rate fresh dialysate is supplied to the first receptacle. This method includes variably withdrawing fresh dialysate from the first receptacle and supplying same to the hemodialyzer, and variable withdrawing spent dialysate from the hemodialyzer and delivering same to the second receptacle. The dialysate levels in the receptacles are maintained at relatively constant, pre-determined levels. Further, this method includes withdrawing a controlled amount of dialysate from the dialysate flow path between and including the receptacles to thereby effect a withdrawal of ultrafiltrate from the patient's blood into the flow path to substantially balance the amount of dialysate withdrawn therefrom.