Patents by Inventor Wilfred F. Mathewson

Wilfred F. Mathewson 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).

  • Patent number: 5338512
    Abstract: A device including an integrally formed membrane oxygenator and heat exchange device positioned in a single housing. The device includes a thermally conductive body formed with a plurality of blood pathways on its surface, and a gas permeable membrane, or membranes positioned in the housing in substantial contact with the heat exchange body to cover or lie within a portion of each of the pathways. The membrane defines a gas pathway separate from the blood pathway through which a gas is directed. The blood is directed through the individual blood pathways. The device also includes various ports and passageways for delivering the blood to the individual channels, and for collecting and removing the blood from the device.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: August 16, 1994
    Assignee: Baxter International Inc.
    Inventors: Wilfred F. Mathewson, Richard L. Bringham, Philip L. Ritger, David L. Karshmer
  • Patent number: 5316724
    Abstract: A membrane oxygenator designed to provide blood flow evenly across a gas permeable membrane in a direction substantially perpendicular to the longitudinal direction of the gas permeable membrane. In particular, the present invention is directed to a membrane oxygenator wherein the blood is distributed substantially evenly and at a substantially constant velocity, in a cross-wise direction across the gas permeable membrane. In accordance with a preferred embodiment, the membrane is a bundle of gas permeable hollow fibers with the blood being distributed in a direction substantially perpendicular to the longitudinal direction of the individual hollow fiber membranes.
    Type: Grant
    Filed: September 15, 1992
    Date of Patent: May 31, 1994
    Assignee: Baxter International Inc.
    Inventors: Wilfred F. Mathewson, Richard L. Bringham, Philip L. Ritger, David Karshmer
  • Patent number: 5290236
    Abstract: A low priming volume centrifugal pump comprising a disc shaped impeller having opposite faces and an inlet hole centrally disposed therein. The impeller has flow channels disposed on at least one of the faces of the impeller which radiate outward from said inlet hole. The volume of the flow channels is small relative to the total impeller envelope volume providing for efficient momentum transfer with a minimum of turbulence and backflow Thus, priming volume is reduced and flow within the pump is more efficient. The pump can be used as stand alone device, or it can be integrated with a blood oxygenator into a common housing.
    Type: Grant
    Filed: July 21, 1992
    Date of Patent: March 1, 1994
    Assignee: Baxter International Inc.
    Inventor: Wilfred F. Mathewson
  • Patent number: 5263924
    Abstract: A low priming volume integrated centrifugal pump and membrane oxygenator comprising a housing containing a mass transfer bed comprising gas permeable hollow membrane fibers placed circumferentially in a ring around an impeller. The mass transfer bed is formed by a multiple wrap of a fiber ribbon comprising at least two layers of fibers bonded in precise orientation with fibers in alternate layers are positioned in line with the opening between fibers in the layers above and below. Adhesion means ensure precise orientation of the fibers. Priming volume is further reduced by a small impeller flow channel volume.
    Type: Grant
    Filed: September 25, 1991
    Date of Patent: November 23, 1993
    Assignee: Baxter International Inc.
    Inventor: Wilfred F. Mathewson
  • Patent number: 5236665
    Abstract: A hollow fiber membrane fluid treatment apparatus for the transfer of mass or energy through the membrane is disclosed. It is designed particularly, but not only, for use in membrane oxygenators. Hollow fiber membranes extend substantially longitudinally, first inert fibers are spaced between them and also extend substantially longitudinally. Second inert fibers extend generally transverse to the hollow fibers and generally contiguous therewith, so that a first fluid (preferably an oxygen-containing gas) can pass through the hollow fibers and a second fluid (preferably blood) can be passed over their exterior for mass or energy transfer through the membrane.
    Type: Grant
    Filed: November 4, 1992
    Date of Patent: August 17, 1993
    Assignee: Baxter International Inc.
    Inventors: Wilfred F. Mathewson, Philip L. Ritger
  • Patent number: 5225161
    Abstract: A device including an integrally formed membrane oxygenator and heat exchange device positioned in a single housing. The device includes a thermally conductive body formed with a plurality of blood pathways on its surface, and a gas permeable membrane, or membranes positioned in the housing in substantial contact with the heat exchange body to cover or lie within a portion of each of the pathways. The membrane defines a gas pathway separate from the blood pathway through which a gas is directed. The blood is directed through the individual blood pathways. The device also includes various ports and passageways for delivering the blood to the individual channels, and for collecting and removing the blood from the device.
    Type: Grant
    Filed: March 10, 1992
    Date of Patent: July 6, 1993
    Assignee: Baxter International Inc.
    Inventors: Wilfred F. Mathewson, Richard L. Bringham, Philip L. Ritger, David L. Karshmer
  • Patent number: 5071609
    Abstract: Interpenetrated matrix of polytetrafluoroethylene and elastomer is disclosed. The matrix is formed into a composite material which is flexible, durable, highly porous with a tight microporous structure and improved retractability. The composite material is subjected to a multi-expansion process to produce shaped articles such as films, tubes, rods and filaments with excellent flexibility and elasticity. More particularly, the composite material can be utilized to produce vascular grafts with excellent biological compatibility.
    Type: Grant
    Filed: November 3, 1988
    Date of Patent: December 10, 1991
    Assignee: Baxter International Inc.
    Inventors: Roger H. Tu, Wilfred F. Mathewson, Mark A. Roberts
  • Patent number: 5024671
    Abstract: A vascular graft at least partially formed from porous hollow fibers, with at least some of the porous hollow fibers being located adjacent an inner surface of the vascular graft. The vascular grafts of the invention have a relatively small pore size for promoting tissue growth while inhibiting bleeding during the healing process. The porous hollow fibers used to form the vascular grafts of the invention further provide a storage situs for temporarily holding a drug or other material for delivery into the blood stream during the healing process. This storage capability may also be used for holding an inert gas while providing the graft with greater resilency and cushioning characteristics than achievable with presently available vascular grafts.
    Type: Grant
    Filed: September 19, 1988
    Date of Patent: June 18, 1991
    Assignee: Baxter International Inc.
    Inventors: Roger Tu, David Chen, Wilfred F. Mathewson
  • Patent number: 4882113
    Abstract: A composition comprising a homogenous mixture of unsintered porous fluoropolymer particles and fluoroelastomers, processes for manufacturing the composition, and devices made from the composition.
    Type: Grant
    Filed: January 26, 1989
    Date of Patent: November 21, 1989
    Assignee: Baxter International Inc.
    Inventors: Roger Tu, Wilfred F. Mathewson