US Patent 9005152 Dialysis system with cassette based balance chambers and volumetric pumps

A dialysis system includes a fresh dialysis fluid membrane pump; a spent dialysis fluid membrane pump; a first balance chamber having a fresh dialysis fluid compartment connected fluidly to the fresh dialysis fluid membrane pump and a spent dialysis fluid compartment connected fluidly to the spent dialysis fluid membrane pump; a second balance chamber having a fresh dialysis fluid compartment connected fluidly to the fresh dialysis fluid membrane pump and a spent dialysis fluid compartment connected fluidly to the spent dialysis fluid membrane pump; and a dialysis fluid cassette, wherein at least one of the fresh dialysis fluid membrane pump, the spent dialysis fluid membrane pump, the first balance chamber and the second balance chamber includes a fluid receiving portion provided in the dialysis fluid cassette.