Patents by Inventor Normal J. Ofsthun

Normal J. Ofsthun has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for removing unwanted materials from fluids and for producing biological products
    Patent number: 5240614
    Abstract: The invention employs dual-skinned membranes useful as one way or rectifying membranes which reduce back filtration of solute molecules in dialysis and which improve nutrient supply and product recovery in membrane bioreactors. The membranes are dual-skinned polymeric materials preferably in the form of hollow fibers. The membranes have sieving coefficient characteristics different for flow of liquids in one direction from that in the opposite direction. Improved dialysis devices are formed by using bundles of the hollow fiber membranes as a dialysis means having rectifying properties. Improved bioreactors are formed by using bundles of hollow fiber as a growth vessel having rectifying properties.
    Type: Grant
    Filed: January 10, 1992
    Date of Patent: August 31, 1993
    Assignee: Baxter International Inc.
    Inventors: Normal J. Ofsthun, Lee W. Henderson, Richard I. Brown, Robin G. Pauley