Patents by Inventor Thomas K Lewellen

Thomas K Lewellen 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: 9442198
    Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.
    Type: Grant
    Filed: April 21, 2015
    Date of Patent: September 13, 2016
    Assignee: University of Washington through its Center for Commercialization
    Inventors: Thomas K. Lewellen, William C. J. Hunter, Robert S. Miyaoka, Lawrence MacDonald
  • Publication number: 20150226862
    Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.
    Type: Application
    Filed: April 21, 2015
    Publication date: August 13, 2015
    Applicant: University of Washington through its Center for Commercialization
    Inventors: Thomas K. Lewellen, William C.J. Hunter, Robert S. Miyaoka, Lawrence MacDonald
  • Patent number: 9040924
    Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.
    Type: Grant
    Filed: October 27, 2010
    Date of Patent: May 26, 2015
    Assignee: University of Washington through its Center for Commercialization
    Inventors: Thomas K. Lewellen, William C. J. Hunter, Robert S. Miyaoka, Lawrence MacDonald
  • Patent number: 8716669
    Abstract: A method for estimating a line or response in a positron emission tomography scanner having depth of interaction estimation capability. The method utilizes information from both detector modules detecting a coincident event. A joint probability density function combining factors accounting for intermediate Compton scattering interactions and/or a final interaction that may be either a Compton scattering interaction or photoelectric absorption is calculated. In a preferred embodiment, a Bayesian estimation scheme is used to integrate the PDF for all permutations of the measured signal pairs, and the permutation with the largest joint probability is selected to construct the estimated line of response.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: May 6, 2014
    Assignee: University of Washington
    Inventors: Robert S. Miyaoka, Kyle Champley, Lawrence MacDonald, Thomas K. Lewellen
  • Publication number: 20140042326
    Abstract: A method is provided for determining the three-dimensional position of an interaction location within a scintillating crystal at which an high-energy photon produces a plurality of scintillation photons. The method includes the use of a sensor-on-entrance-surface photodetector device to determine a distribution pattern of the scintillation photons in the crystal.
    Type: Application
    Filed: January 25, 2013
    Publication date: February 13, 2014
    Applicant: UNIVERSITY OF WASHINGTON
    Inventors: Robert S. Miyaoka, Thomas K. Lewellen, Tao Ling
  • Patent number: 8431904
    Abstract: Improved processing electronic hardware are disclosed that facilitate the efficient processing of PET system data, while enhancing accuracy and compatibility of PET systems with other analytical methods (e.g., magnetic resonance imaging). Improvements include the use of an application-specific integrated circuit (ASIC) for summing, by row, column, and diagonal, the output signals from an array of photodetectors in the PET system.
    Type: Grant
    Filed: October 26, 2009
    Date of Patent: April 30, 2013
    Assignee: University of Washington
    Inventors: Thomas K. Lewellen, Robert S. Miyaoka
  • Patent number: 8309932
    Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A composite reference pulse curve is calculated to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, the composite reference pulse curve shape is used to estimate the pulse start time.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: November 13, 2012
    Assignee: University of Washington
    Inventors: Michael Haselman, Robert S. Miyaoka, Thomas K. Lewellen, Scott Hauck
  • Publication number: 20120235047
    Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.
    Type: Application
    Filed: October 27, 2010
    Publication date: September 20, 2012
    Applicant: University of Washington through its Center for Commercialization
    Inventors: Thomas K. Lewellen, William C. J. Hunter, Robert S. Miyaoka, Lawrence MacDonald
  • Publication number: 20120138804
    Abstract: A method for estimating a line or response in a positron emission tomography scanner having depth of interaction estimation capability. The method utilizes information from both detector modules detecting a coincident event. A joint probability density function combining factors accounting for intermediate Compton scattering interactions and/or a final interaction that may be either a Compton scattering interaction or photoelectric absorption is calculated. In a preferred embodiment, a Bayesian estimation scheme is used to integrate the PDF for all permutations of the measured signal pairs, and the permutation with the largest joint probability is selected to construct the estimated line of response.
    Type: Application
    Filed: October 22, 2009
    Publication date: June 7, 2012
    Applicant: UNIVERSITY OF WASHINGTON
    Inventors: Robert S. Miyaoka, Kyle Champley, Lawrence MacDonald, Thomas K. Lewellen
  • Publication number: 20110301918
    Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A composite reference pulse curve is calculated to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, the composite reference pulse curve shape is used to estimate the pulse start time.
    Type: Application
    Filed: August 18, 2011
    Publication date: December 8, 2011
    Applicant: WASHINGTON, UNIVERSITY OF
    Inventors: Michael Haselman, Robert S. Miyaoka, Thomas K. Lewellen, Scott Hauck
  • Publication number: 20110215248
    Abstract: Improved processing electronic hardware are disclosed that facilitate the efficient processing of PET system data, while enhancing accuracy and compatibility of PET systems with other analytical methods (e.g., magnetic resonance imaging).
    Type: Application
    Filed: October 26, 2009
    Publication date: September 8, 2011
    Applicant: UNIVERSITY OF WASHINGTON
    Inventors: Thomas K. Lewellen, Robert S. Miyaoka
  • Patent number: 8003948
    Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A parameterized ideal curve shape is selected to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, a curve from the parameterized ideal curve shape is selected, that best represents the received analog pulse signal, and the selected curve is used to estimate the pulse start time.
    Type: Grant
    Filed: November 3, 2008
    Date of Patent: August 23, 2011
    Assignee: University of Washington
    Inventors: Michael Haselman, Robert S. Miyaoka, Thomas K. Lewellen, Scott Hauck
  • Patent number: 7869860
    Abstract: A method is disclosed for obtaining linear attenuation coefficients for interpreting a PET scan of a region. The method is suitable for use when high molecular weight materials are present in the region, such as contrast agents or metal objects. The method includes obtaining first and second x-ray CT data sets of the region of interest at two different energies or voltage potentials and differencing corresponding CT numbers. The difference values are used to distinguish portions of the region that are bone from portions of the region that are contrast agent or other high molecular weight material. The obtained CT data set is then used to obtain an attenuation coefficient map of the region at the PET energy of 511 keV, for example, using a linear scaling factor suited to the particular identified material. Difference values at or near zero may be used to identify soft tissue portions of the region.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: January 11, 2011
    Assignee: University of Washington
    Inventors: Paul E Kinahan, Adam M Alessio, Thomas K Lewellen, Hubert J Vesselle
  • Publication number: 20100044571
    Abstract: A method is provided for determining the three-dimensional position of an interaction location within a scintillating crystal at which an high-energy photon produces a plurality of scintillation photons. The method includes the use of a sensor-on-entrance-surface photodetector device to determine a distribution pattern of the scintillation photons in the crystal.
    Type: Application
    Filed: August 19, 2009
    Publication date: February 25, 2010
    Applicant: UNIVERSITY OF WASHINGTON
    Inventors: Robert S. Miyaoka, Thomas K. Lewellen, Tao Ling
  • Publication number: 20090224158
    Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A parameterized ideal curve shape is selected to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, a curve from the parameterized ideal curve shape is selected, that best represents the received analog pulse signal, and the selected curve is used to estimate the pulse start time.
    Type: Application
    Filed: November 3, 2008
    Publication date: September 10, 2009
    Applicant: WASHINGTON, UNIVERSITY OF
    Inventors: Michael Haselman, Robert S. Miyaoka, Thomas K. Lewellen, Scott Hauck