Patents by Inventor Douglas M. Stevens

Douglas M. Stevens 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: 10768151
    Abstract: Processing mass spectral data may include performing one or more experiments using one or more samples, each experiment including mass analysis using a mass spectrometer; acquiring one or more raw mass spectral data sets as a result of performing the one or more experiments; receiving selection criteria; filtering the one or more raw mass spectral data sets in accordance with the selection criteria; and generating a chromatogram as a result of said filtering, wherein the chromatogram displays signal intensity as a function of scan time for a plurality of scan times and includes a non-zero signal intensity at each scan time only if, at the scan time, the selection criteria is met and otherwise the chromatogram includes a zero signal intensity at the scan time. The mass spectrometer may alternate between low and elevated energy modes and acquire two of the raw mass spectral data sets concurrently.
    Type: Grant
    Filed: September 11, 2015
    Date of Patent: September 8, 2020
    Assignee: Waters Technologies Corporation
    Inventor: Douglas M. Stevens
  • Patent number: 10732157
    Abstract: Processing mass spectral data may include performing one or more experiments using one or more samples, each experiment including mass analysis using a mass spectrometer; acquiring one or more raw mass spectral data sets as a result of performing the one or more experiments; receiving selection criteria; filtering the one or more raw mass spectral data sets in accordance with the selection criteria; and generating a chromatogram as a result of said filtering, wherein the chromatogram displays signal intensity as a function of scan time for a plurality of scan times and includes a non-zero signal intensity at each scan time only if, at the scan time, the selection criteria is met and otherwise the chromatogram includes a zero signal intensity at the scan time. The mass spectrometer may alternate between low and elevated energy modes and acquire two of the raw mass spectral data sets concurrently.
    Type: Grant
    Filed: September 11, 2015
    Date of Patent: August 4, 2020
    Assignee: Waters Technologies Corporation
    Inventor: Douglas M. Stevens
  • Patent number: 10386333
    Abstract: A gas chromatography-mass spectrometry (GC-MS) method that includes performing a first GC-MS run on a sample using a gas chromatography-mass spectrometry system. Performing the first GC-MS nm includes i) passing a first flow of a carrier gas carrying a first portion of the sample through a gas chromatograph to provide a first effluent; ii) generating first ions under protonation conditions by passing the first effluent through an atmospheric pressure ionization source; iii) passing the first ions through a mass spectrometer; and iv) recording first GC-MS data for the first ions. The method also include performing a second GC-MS run on the sample using the gas chromatography-mass spectrometry system.
    Type: Grant
    Filed: January 30, 2013
    Date of Patent: August 20, 2019
    Assignee: WATERS TECHNOLOGY CORPORATION
    Inventor: Douglas M. Stevens
  • Patent number: 9903845
    Abstract: An apparatus for ionizing analyte molecules comprised in a flow of a first gas. The apparatus includes an inlet tube through which the first gas may be discharged into an ionization region. The apparatus also includes a nozzle electrode disposed around the inlet tube to define a substantially annular space between the exterior of the inlet tube and the interior of the nozzle electrode. The sheath tube includes an inlet for introducing a fluid into the substantially annular space and an outlet through which the fluid may be discharged into the ionization region. The apparatus is configured to ionize the analyte molecules optionally via electrospray or chemical ionization.
    Type: Grant
    Filed: January 30, 2013
    Date of Patent: February 27, 2018
    Assignee: WATERS TECHNOLOGIES CORPORATION
    Inventor: Douglas M. Stevens
  • Publication number: 20170299558
    Abstract: Processing mass spectral data may include performing one or more experiments using one or more samples, each experiment including mass analysis using a mass spectrometer; acquiring one or more raw mass spectral data sets as a result of performing the one or more experiments; receiving selection criteria; filtering the one or more raw mass spectral data sets in accordance with the selection criteria; and generating a chromatogram as a result of said filtering, wherein the chromatogram displays signal intensity as a function of scan time for a plurality of scan times and includes a non-zero signal intensity at each scan time only if, at the scan time, the selection criteria is met and otherwise the chromatogram includes a zero signal intensity at the scan time. The mass spectrometer may alternate between low and elevated energy modes and acquire two of the raw mass spectral data sets concurrently.
    Type: Application
    Filed: September 11, 2015
    Publication date: October 19, 2017
    Applicant: Waters Technologies Corporation
    Inventor: Douglas M. Stevens
  • Publication number: 20150338384
    Abstract: An apparatus for ionizing analyte molecules comprised in a flow of a first gas. The apparatus includes an inlet tube through which the first gas may be discharged into an ionization region. The apparatus also includes a nozzle electrode disposed around the inlet tube to define a substantially annular space between the exterior of the inlet tube and the interior of the nozzle electrode. The sheath tube includes an inlet for introducing a fluid into the substantially annular space and an outlet through which the fluid may be discharged into the ionization region. The apparatus is configured to ionize the analyte molecules optionally via electrospray or chemical ionization.
    Type: Application
    Filed: January 30, 2013
    Publication date: November 26, 2015
    Applicant: WATERS TECHNOLOGIES CORPORATION
    Inventor: Douglas M. Stevens
  • Publication number: 20150024510
    Abstract: A gas chromatography-mass spectrometry (GC-MS) method that includes performing a first GC-MS run on a sample using a gas chromatography-mass spectrometry system. Performing the first GC-MS nm includes i) passing a first flow of a carrier gas carrying a first portion of the sample through a gas chromatograph to provide a first effluent; ii) generating first ions under protonation conditions by passing the first effluent through an atmospheric pressure ionization source; iii) passing the first ions through a mass spectrometer; and iv) recording first GC-MS data for the first ions. The method also include performing a second GC-MS run on the sample using the gas chromatography-mass spectrometry system.
    Type: Application
    Filed: January 30, 2013
    Publication date: January 22, 2015
    Applicant: WATERS TECHNOLOGIES CORPORATION
    Inventor: Douglas M. Stevens
  • Publication number: 20140370613
    Abstract: An atmospheric pressure chemical ionization detector includes a reaction chamber that is configured to receive gas phase analytes. An electrode is disposed within the reaction chamber and is configured to ionize the gas phase analytes via corona discharge. A collector is disposed adjacent an outlet of the reaction chamber and is configured to attract ions from the chamber such that the ions hit the collector to induce a measurable current. The detector is configured for non-mass spectrometric detection of gas phase analyte ions.
    Type: Application
    Filed: December 10, 2012
    Publication date: December 18, 2014
    Applicant: Waters Technologies Corporation
    Inventor: Douglas M. Stevens