Patents by Inventor Robert J. Levis

Robert J. Levis 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: 20150187558
    Abstract: The present invention relates to a mass spectrometer system, which combines laser desorption with pulse bursts comprising a train of ultrashort pulses and electrospray ionization. The pulse separation between individual pulses within the pulse burst is selected such that transient phenomena on an irradiated sample do not fully relax between individual pulses. Pulses with pulse widths ranging from fs to sub ns are conveniently implemented. The pulse widths can be selected to allow for multi-photon excitation of a sample while at the same time minimizing heat accumulation in a sample. Low cost laser systems such as fiber lasers can be configured to generate appropriate pulse bursts. The technique is suitable for mass spectrometry imaging with high spatial resolution. The laser system can serve as an electronic clock to which the whole mass spectrometry system or mass spectrometry imaging system is synchronized.
    Type: Application
    Filed: December 27, 2013
    Publication date: July 2, 2015
    Applicant: IMRA AMERICA, INC.
    Inventors: Andrew A. MILLS, Martin E. FERMANN, Jiahui PENG, Robert J. LEVIS
  • Patent number: 9001325
    Abstract: In apparatus and methods of Raman spectroscopy in air, a target region is excited by a laser pump pulse exceeding the critical power for self-focusing in air and having a duration after self-focusing of 15 fs or less. A laser probe pulse having a duration in the range of 200 fs to 100 ps and an energy of at least 20 ?J is directed at the excited target region. Stimulated Raman scattering from the interaction between the excited target region and the laser probe pulse is detected. The target region can be outside the spectrometer, with ambient air in between used for the self-focusing.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: April 7, 2015
    Assignee: Temple University —Of The Commonwealth System of Higher Education
    Inventors: Robert J. Levis, Johanan H. Odhner
  • Patent number: 8685293
    Abstract: Our invention allows for control of particle formation at the nanoscale, providing a means to control nanoparticle and nanostructure formation using feedback on the fly from nanoparticle characteristic analysis and optimization/knowledge extraction control algorithms. A closed loop feedback controller causes the interaction of a shaped flaser pulse with a substrate. The substrate can be one or more solid, liquid or gas or any combination thereof. Nanoparticles are produced and their characteristics are measured. The measured characteristics are compared with the desired nanoparticle characteristics. If the measured and desired characteristics are not equivalent, the closed loop feedback controller modifies the shape of the laser pulse and the next cycle begins. With successive loop of the control process the difference between the desired and measured characteristics converges until they are equivalent.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: April 1, 2014
    Inventors: Nicholas V. Coppa, Robert J. Levis
  • Publication number: 20130321801
    Abstract: In apparatus and methods of Raman spectroscopy in air, a target region is excited by a laser pump pulse exceeding the critical power for self-focusing in air and having a duration after self-focusing of 15 fs or less. A laser probe pulse having a duration in the range of 200 fs to 100 ps and an energy of at least 20 ?J is directed at the excited target region. Stimulated Raman scattering from the interaction between the excited target region and the laser probe pulse is detected. The target region can be outside the spectrometer, with ambient air in between used for the self-focusing.
    Type: Application
    Filed: February 3, 2012
    Publication date: December 5, 2013
    Applicant: TEMPLE UNIVERSITY - OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION
    Inventors: Robert J. Levis, Johanan H. Odhner
  • Patent number: 8598521
    Abstract: Methods and apparatus for analyzing samples are disclosed. The samples are analyzed by vaporizing molecules from a sample in a sample area with a femtosecond laser beam under ambient conditions, ionizing the vaporized molecules with electrospray ionization under the ambient conditions to form ions; and analyzing and detecting the ions.
    Type: Grant
    Filed: August 17, 2010
    Date of Patent: December 3, 2013
    Assignee: Temple University of the Commonwealth System of Higher Education
    Inventors: Robert J. Levis, John J. Brady, Elizabeth J. Judge
  • Publication number: 20120149009
    Abstract: Methods and apparatus for analyzing samples are disclosed. The samples are analyzed by vaporizing molecules from a sample in a sample area with a femtosecond laser beam under ambient conditions, ionizing the vaporized molecules with electrospray ionization under the ambient conditions to form ions; and analyzing and detecting the ions.
    Type: Application
    Filed: August 17, 2010
    Publication date: June 14, 2012
    Inventors: Robert J. Levis, John J. Brady, Elizabeth J. Judge
  • Publication number: 20040128081
    Abstract: The disclosed invention is related to the field of quantum dynamic discriminators, sample identification systems, mass spectrometers and methods for identifying a component in a composition. Also disclosed are quantum dynamic discriminators and methods for ascertaining the quantum dynamic states of a component in a composition. Optimal identification devices and methods for ascertaining quantum Hamiltonians of quantum systems are further disclosed.
    Type: Application
    Filed: December 18, 2002
    Publication date: July 1, 2004
    Inventors: Herschel Rabitz, Elmar Schreiber, Robert J. Levis
  • Patent number: 5580733
    Abstract: Method for analyzing a nucleic acid molecule, without fragmenting the molecule, by vaporizing a mixture of the molecule and a matrix by illuminating the mixture with visible laser light absorbed by the matrix and not by the nucleic acid molecule. The method is useful for determining the nucleotide sequence of a polynucleotide by using mass spectrometry to determine the molecular weights of individual single-stranded nucleic acid molecules in a population including a plurality of single-stranded nucleic acid molecules generated from the polynucleotide, each molecule having a different molecular weight, and one defined terminus and one variable terminus which terminates at a specific nucleotide.
    Type: Grant
    Filed: September 6, 1994
    Date of Patent: December 3, 1996
    Assignee: Wayne State University
    Inventors: Robert J. Levis, Louis J. Romano
  • Patent number: 5210412
    Abstract: Described is a method and apparatus for analyzing an organic sample. In the preferred embodiment, this method and apparatus allows the determination of the base sequence of a nucleic acid by determining the molecular weights of the components of a biological sample. The method uses either a pre-existing chromophore or the covalent attachment of an ionizable chromophore to a biological sample followed by the vaporization of these molecules by exposure to an intense pulse of electromagnetic radiation in the presence of a matrix which strongly absorbs the radiation. The gaseous molecules are subsequently extracted into an evacuated ionization chamber and then exposed to electromagnetic radiation at a wavelength which specifically excites the chromophore covalently attached to the biological sample. The molecular weights of these ionized species are then determined by mass spectroscopic analysis. This method of molecular weight determination allows for a DNA sequencing method.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: May 11, 1993
    Assignee: Wayne State University
    Inventors: Robert J. Levis, Louis J. Romano