Patents by Inventor David A. Witsoe

David A. Witsoe 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 draining dialysate from artificial kidney
    Patent number: 4331540
    Abstract: There is disclosed herein a dialysis machine: (a) to which a negative pressure dialyzer can be connected; and (b) which can be operated so as to drain the dialysis solution from the dialyzer through the lower of the dialysis solution inlet and outlet ports. This apparatus and method permit a dialyzer to be drained of dialysis solution at the end of the dialysis treatment session in such a manner as to prevent spillage and leakage associated with the removal of the dialyzer from the machine.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: May 25, 1982
    Assignee: Baxter Travenol Laboratories, Inc.
    Inventor: David A. Witsoe
  • Impedance plethysmograph
    Patent number: RE30101
    Abstract: .Iadd.Cardiac output is measured by connecting excitation electrodes at the upper and lower ends of the thorax of a mammalian subject, connecting measuring electrodes to the thorax between the excitation electrodes, applying a constant fluctuating excitation current to the excitation electrodes, measuring, with appropriate circuitry, changes in impedance within the thorax, and simultaneously measuring the beginning and end of systole, and determining cardiac output by measuring the maximum decreasing impedance slope during systole..Iaddend.
    Type: Grant
    Filed: June 23, 1975
    Date of Patent: September 25, 1979
    Assignee: Regents of the University of Minnesota
    Inventors: William G. Kubicek, Edwin Kinnen, Robert P. Patterson, David A. Witsoe