Patent ID: 8235931

Claim:
A waste-balancing system for an extracorporeal blood system, the waste-balancing system comprising: a blood treatment machine with a fluid circuit having at least one blood treatment component configured to receive and cleanse blood of uremic toxins, further configured to receive a treatment fluid consumed in the process of cleansing the blood and to produce a waste fluid, a blood treatment performed by said blood treatment machine requiring a predetermined ratio between the rate of flow of the treatment fluid and the rate of flow of the waste fluid; a waste fluid line configured to receive waste fluid from the at least one blood treatment component; a treatment fluid line configured to convey treatment fluid to the at least one blood treatment component; a first pump module configured to pump waste fluid through the waste fluid line; and a second pump module configured to pump treatment fluid through the treatment fluid line, wherein the first and second pump modules have respective fluid forcing members that are mechanically coupled to form a single moving device, such that pumping by the first pump module of a quantity of waste fluid results in pumping by the second pump module of a proportional quantity of treatment fluid, the first pump module includes a first rotor, the second pump module includes a second rotor, and the first and second rotors are supported on a common shaft.