Patent ID: 9737653
Date: 2017-08-22
CPC Classifications: A61M,B01D

Claim:
1. A device for selective ultrafiltration of a fluid containing molecules of first and a second solute, by selectively retaining the first solute while passing the second solute, comprising: a housing; a main filtration chamber inside the housing; an inlet port passing through the housing configured to receive the fluid; an outlet port passing through the housing configured to return the fluid to a feed flow; an ultrafiltration membrane contained in the main filtration chamber to divide the main filtration chamber into at least two interior chambers, a first of the at least two interior chambers being a feed chamber to contain the fluid and a second of the at least two chambers being a permeate chamber, the ultrafiltration membrane comprising pores sized to allow passage of the similarly-sized molecules and establish a sieving coefficient for each of the first and second solutes across the ultrafiltration membrane; and a permeate solution, contained in the permeate chamber, the permeate solution comprising an additive solute that is selected so that the presence of the additive solute in the permeate solution decreases the sieving coefficient of the first solute across the ultrafiltration membrane relative to the sieving coefficient of the second solute across the ultrafiltration membrane, while the pores render the membrane substantially impermeable to the additive solute.