Abstract: There is provided an improved system for controlling ultrafiltration in hemodialysis which is independent of the membrane used in the dialyzer. A load cell measures the instantaneous amounts of fluid in a reservoir which receives fluids from the dialyzer and feeds this information into an electronic controller which has been programmed for the desired ultrafiltration. The controller generates an error signal and controls a negative pressure control valve which, in turn, determines the rate and thus amount of ultrafiltration.

Abstract: There is provided a peristaltic pump which has a base member and a rotor attached to the base member. The rotor is adapted to receive a resilient collapsible tube. The pump further includes a stator having a fixed member disposed in a permanent position relative to the rotor. A door stator is connected to the fixed stator, and the entire stator will confront the periphery of the rotor over at least uninterrupted 180.degree. concave surface. A latch is provided on the door stator, so that it may pivot outward for ease of removal of the tubing.

Abstract: A pinch-type shut-off, pressure- or flow-regulating valve having a flexible tube extending through a valve body wherein the flexible tube is pinched off by the action of an eccentric cam attached to a motor. As the eccentric cam is rotated the flexible tube can be pinched off as it presses against the opposing wall inside the valve body. A number of positions of pinching off can be achieved and a microswitch can be available to locate the position of the eccentric cam.

Abstract: A process for making particulate substantially water-insoluble magnesium phosphate product and method of use of the product for removing ammonia from aqueous solutions. The particulate magnesium phosphate product acts as a remarkably effective scavenger wherein under equilibrium conditions only about six (6) grams of the product are required to bind the ammonia (more exactly, ammonium ions) liberated from one (1) gram of the urea, a result far superior to traditional zirconium phosphate (ZP) prior art materials which under ideal conditions require about 17 to 20 grams of ZP per gram of urea. The particulate magnesium phosphate product can also be used for the removal of ammonium ions either produced by enzymatic or non-enzymatic hydrolysis of urea or proteins or amino acids or available as NH.sub.4.sup.+ from its native source. The magnesium phosphate product is made by forming a slurry of water and magnesium hydroxide in the presence of a phosphate ion-containing buffer having a pH of about 6.5 to about 8.

Abstract: There is disclosed a sodium zirconium carbonate compound and the method of its preparation. The sodium zirconium carbonate compound is formed from a metastable aqueous solution comprising zirconium, sodium, sulfate, and carbonate ions.

Abstract: There is disclosed a sodium zirconium carbonate compound and the method of its preparation. The sodium zirconium carbonate compound is formed from a metastable aqueous solution comprising zirconium, sodium, sulfate, and carbonate ions.