Patents by Inventor James N. Demas

James N. Demas 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).

  • Publication number: 20180355242
    Abstract: Disclosed herein are methods and related imaging systems to measure oxygenation levels on a surface. Methods of monitoring wound healing with dual emissive difluoroboron naphthyl-phenyl ?-diketonate polylactide materials are disclosed.
    Type: Application
    Filed: December 12, 2016
    Publication date: December 13, 2018
    Inventors: Cassandra L. FRASER, James N. DEMAS, Shayn PEIRCE-COTTLER, Alexander MATTHEW, Christopher DEROSA, Scott SEAMAN
  • Patent number: 7749765
    Abstract: The present invention provides compositions and methods for extracting, isolating, and measuring lead dissolved in aqueous solutions, including water.
    Type: Grant
    Filed: August 3, 2006
    Date of Patent: July 6, 2010
    Assignee: University of Virginia Patent Foundation
    Inventors: James N. Demas, Wenying Xu
  • Publication number: 20080280366
    Abstract: The present invention provides compositions and methods for extracting, isolating, and measuring lead dissolved in aqueous solutions, including water.
    Type: Application
    Filed: August 3, 2006
    Publication date: November 13, 2008
    Inventors: James N. Demas, Wenying Xu
  • Patent number: 5834204
    Abstract: The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.
    Type: Grant
    Filed: December 12, 1997
    Date of Patent: November 10, 1998
    Assignee: The Regents of the University of California
    Inventors: Rhett L. Affleck, W. Patrick Ambrose, James N. Demas, Peter M. Goodwin, Mitchell E. Johnson, Richard A. Keller, Jeffrey T. Petty, Jay A. Schecker, Ming Wu
  • Patent number: 5827663
    Abstract: The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: October 27, 1998
    Assignee: The Regents of the University of California
    Inventors: Rhett L. Affleck, W. Patrick Ambrose, James N. Demas, Peter M. Goodwin, Mitchell E. Johnson, Richard A. Keller, Jeffrey T. Petty, Jay A. Schecker, Ming Wu
  • Patent number: 5799682
    Abstract: An analyte fluid stream with first molecules having relatively low molecular weight and a corresponding high coefficient of diffusion has reduced diffusional defocusing out of an analyte fluid stream. The analyte fluid stream of first molecules is associated with second molecules of relatively high molecular weight having a relatively low coefficient of diffusion and a binding constant effective to associate with the first molecules. A focused analyte fluid stream is maintained since the combined molecular weight of the associated first and second molecules is effective to minimize diffusion of the first molecules out of the analyte fluid stream.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: September 1, 1998
    Assignee: The Regents of the University of California
    Inventors: Rhett L. Affleck, James N. Demas, Peter M. Goodwin, Richard Keller, Ming Wu
  • Patent number: 5030420
    Abstract: Quenching luminescence of the tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) perchorate, immobilized in a silicone rubber by oxygen is shown to be an accurate and precise method for measuring oxygen concentration in solutions and in the gas phase. Quenching can be quantitated by either lifetime or intensity quenching measurements. Strong aqueous acids and bases, complexing agents, oxidants, and reductants do not penetrate the hydrophobic polymer and, therefore, do not affect the response. Gaseous interferents, such as H.sub.2 S, anesthesia gases (e.g. N.sub.2 O, Halothane), and fluorocarbons do not affect the response. Chlorine and especially SO.sub.2 cause strong, but reversible interference presumably because of electron transfer quenching. A system with a response time of less <0.2 s is disclosed, which is adequate for the monitoring of breathing subjects.
    Type: Grant
    Filed: February 3, 1986
    Date of Patent: July 9, 1991
    Assignee: University of Virginia Alumni Patents Foundation
    Inventors: John R. Bacon, James N. Demas
  • Patent number: 4845368
    Abstract: Method for reducing quenching effects in analytical luminescence measurements. Two embodiments of the present invention are described which relate to a form of time resolution based on the amplitudes and phase shifts of modulated emission signals. In the first embodiment, the measured modulated emission signal is substantially independent of sample quenching at sufficiently high frequenices. In the second embodiment, the modulated amplitude and the phase shift between the emission signal and the excitation source are simultaneously measured. Using either method, the observed modulated amplitude may reduced to tis unquenched value.
    Type: Grant
    Filed: June 26, 1987
    Date of Patent: July 4, 1989
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: James N. Demas, Wesley M. Jones, Richard A. Keller