Patents by Inventor John Bridgham

John Bridgham 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).

  • Measurement of oxygen by differential absorption of UV radiation
    Patent number: 4192996
    Abstract: A device is provided for measuring the concentration of oxygen in a sample utilizing the differential absorption by oxygen (O.sub.2) of two closely spaced ultraviolet (UV) radiation lines. The two UV lines are preferably isotope-shifted Hg lines in the vicinity of the Hg atomic transistion line at 1849.5A.
    Type: Grant
    Filed: July 12, 1978
    Date of Patent: March 11, 1980
    Assignee: Hewlett-Packard Company
    Inventors: Melvyn N. Kronick, Charles E. Bryson, III, John A. Bridgham, Sam H. Eletr
  • Medical-analytical gas detector
    Patent number: 4075481
    Abstract: A gas analyzer is provided which is particularly suited for making transcutaneous measurement of the CO.sub.2 concentration in the blood.In accordance with one embodiment of the invention, sample gases from the body are circulated in a cavity of the device. A rotating wheel in the cavity includes two reference cells and a sample cell which are sequentially rotated into the optical path between a source and a detector. Three signals are thereby provided which may be combined to give an output indication of the CO.sub.2 concentration in the body fluids. In a preferred embodiment, the sample cell is an "inverted cell" being in open communication with the sample gas circulating in the device so that the gas in the sample cell is a portion of the circulating gas which also surrounds the two reference cells. An output indication is thereby obtained which is insensitive to contaminants in the sample.
    Type: Grant
    Filed: June 14, 1976
    Date of Patent: February 21, 1978
    Assignee: Hewlett-Packard Company
    Inventors: Paul E. Stoft, John A. Bridgham, Robert L. Chaney, Charles M. Hill, John K. D. Lazier, Barry G. Willis, Jacob Y. Wong, Moshe A. Fostick
  • Medical-analytical gas detector
    Patent number: 3987303
    Abstract: A gas analyzer is provided which is particularly suited for making transcutaneous measurement of the CO.sub.2 concentration in the blood.In accordance with one embodiment of the invention, sample gases from the body are circulated in a cavity of the device. A rotating wheel in the cavity includes two reference cells and a sample cell which are sequentially rotated into the optical path between a source and a detector. Three signals are thereby provided which may be combined to give an output indication of the CO.sub.2 concentration in the body fluids. In a preferred embodiment, the sample cell is an "inverted cell" being in open communication with the sample gas circulating in the device so that the gas in the sample cell is a portion of the circulating gas which also surrounds the two reference cells. An output indication is thereby obtained which is insensitive to contaminants in the sample.
    Type: Grant
    Filed: February 6, 1975
    Date of Patent: October 19, 1976
    Assignee: Hewlett-Packard Company
    Inventors: Paul E. Stoft, John A. Bridgham, Robert L. Chaney, Charles M. Hill, John K. D. Lazier, Barry G. Willis, Jacob Y. Wong, Moshe A. Fostick