Patents by Inventor Keith D. Paulsen

Keith D. Paulsen 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: 8207733
    Abstract: A microwave imaging system provides superior breast imaging resolution by combining MR microwave absorption and MR-compatible microwave tomography calculations. These techniques may also be supplemented with magnetic resonance elastography techniques, for example, to facilitate quick multispectral imaging.
    Type: Grant
    Filed: October 6, 2008
    Date of Patent: June 26, 2012
    Assignee: The Trustees of Dartmouth College
    Inventors: Paul M. Meaney, Keith D. Paulsen, John B. Weaver
  • Publication number: 20110275932
    Abstract: A tomographic fluorescent imaging device for imaging fluorophores in biological tissues has a scanned laser for scanning the tissue and a camera for receiving light from the biological tissue at an angle to the beam at a second wavelength ten or more nanometers greater in wavelength than the wavelength of the laser. Use of both intrinsic and extrinsic fluorophores is described. Images are obtained at each of several positions of the beam. An image processing system receives the series of images, models a path of the beam through the tissue, and determines depth of fluorophore in tissue from intersections of the modeled path of the beam and the path of the received light. The laser is of 600 nm or longer wavelength, to provide penetration of tissue. The imaging device is used during surgery to visualize lesions of various types to ensure complete removal of malignant tumors.
    Type: Application
    Filed: December 4, 2009
    Publication date: November 10, 2011
    Inventors: Frederic Leblond, David W. Roberts, Brian W. Pogue, Keith D. Paulsen, Alex Hartov, Scott C. Davis, Dax Kepshire
  • Patent number: 8000775
    Abstract: Optical tomography systems that provide light of multiple distinct wavelengths from a plurality of sources are described. The systems direct light into mammalian tissue, and light from the mammalian tissue is collected at a plurality of reception points. Collected light from each reception point is separated according to its wavelength, and received by a photodetector to produce path attenuation signals representing attenuation along paths between the source locations and the reception points. An image construction system generates a tomographic image of the mammalian tissue from the path attenuation signals. One embodiment of an optical imaging system includes an optical coherence tomography-near infrared probe. The systems and methods may utilize a spectral derivative approach that provides insensitivity to the boundary and boundary artifacts in the signal, thereby improving the quality of the reconstructed images.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: August 16, 2011
    Assignee: The Trustees of Dartmouth College
    Inventors: Brian William Pogue, Daqing Piao, Keith D. Paulsen, Shudong Jiang, Hamid Dehghani, Heng Xu, Roger Springett, Subhadra Srinivasan
  • Publication number: 20110153254
    Abstract: A method of calibrating a transformation of ultrasound data in an imaging system from a first coordinate system into a second coordinate system, the method comprising applying a transformation having parameters. The parameters are calibrated by imaging a planar object, extracting points corresponding to ultrasound rays intersecting the planar object, and fitting the parameters such that the points when transformed by the transformation describe a planar surface in the second coordinate system.
    Type: Application
    Filed: May 22, 2009
    Publication date: June 23, 2011
    Inventors: Alexander Hartov, Keith D. Paulsen, David William Roberts
  • Publication number: 20110130656
    Abstract: Provided are microwave image reconstruction apparatus and method. An apparatus for diagnosing a breast cancer, includes: a plurality of antennas for inserting a breast and configured to transmit and receive the electromagnetic wave; an electromagnetic wave transceiver configured to receive phase and amplitude information of the electromagnetic wave; an initial distribution value provider configured to set an initial dielectric constant and conductivity distribution value for dielectric constant and conductivity of a breast of a patient and in the tank; a first image reconstruction unit configured to transform the amplitude information of the electromagnetic wave through log transform and to obtain a first image by calculating a phase and amplitude information value of electric field generated from the electromagnetic wave; and a second image reconstruction unit configured to transform the first image in a value in a complex number form and to transform values to a second image.
    Type: Application
    Filed: November 30, 2009
    Publication date: June 2, 2011
    Inventors: Seong-Ho SON, Hyuk-Je KIM, Jong-Moon LEE, Soon-Ik JEON, Pual M. MEANEY, Keith D. PAULSEN, Tomasz M. GRZEGORCZYK
  • Publication number: 20110034806
    Abstract: A dual imaging probe 300 for obtaining both ultrasound and electrical impedance data is disclosed along with methods of using the dual imaging probe 300 to interrogate tissue. An electrical impedance imaging overlay 330 is adapted to be positioned on a transducer window 304 of an ultrasound probe 320, and may be integrally formed as part of the ultrasound probe 320 or as a modular adapter for coupling with, and optionally uncoupling from, an ultrasound probe 320 to form the dual imaging probe 300. A method (FIG. 6) of reconstructing composite images using both ultrasound and electrical impedance data is described. Applications for medical diagnosis are described. A particular use for prostate imaging is described.
    Type: Application
    Filed: January 7, 2009
    Publication date: February 10, 2011
    Applicant: THE TRUSTEES OF DARTMOUTH COLLEGE
    Inventors: Alex Hartov, Keith D. Paulsen
  • Patent number: 7825667
    Abstract: A microwave imaging process, and a system controlled by an associated software product, illuminate a target with microwaves from a transmitting antenna. Receiving antennas receive microwaves scattered by the target, and form microwave data. The illumination and receiving repeat over multiple transmitting antennas and multiple microwave frequencies. The microwave data is processed to form permittivity and conductivity images by selecting a background dispersion model for permittivity and conductivity. Permittivity and conductivity dispersion coefficients are determined, and permittivity and conductivity distributions are calculated, for each of the microwave frequencies. Forward solutions at multiple frequencies are determined from property distributions, and a dispersion coefficient based Jacobian matrix is determined. Dispersion coefficient updates are determined using the microwave data, and the dispersion coefficients are updated.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: November 2, 2010
    Assignee: Microwave Imaging Systems Technologies, Inc.
    Inventors: Qianqian Fang, Paul M. Meaney, Keith D. Paulsen
  • Publication number: 20100265493
    Abstract: A diffuse optical tomography system incorporating a mode-locked, tunable laser produces pulsed light that may be used to interrogate tissue with high spatial and spectral resolution. The detection signal may be heterodyne shifted to lower frequencies to allow easy and accurate measurement of phase and amplitude. Embodiments incorporating wavelength-swept, tunable, lasers and embodiments using broadband photonic fiber lasers with spectrally-sensitive detectors are described.
    Type: Application
    Filed: June 20, 2008
    Publication date: October 21, 2010
    Inventors: Shudong Jiang, Brian William Pogue, Jia Wang, Keith D. Paulsen
  • Patent number: 7755010
    Abstract: A non-invasive microwave analysis method determines scattered phase and/or amplitude data for a liquid in a container. A transmitter antenna transmits microwaves that scatter from the container and the liquid in the container. One or more receiver antennas convert the microwaves into microwave electronic signals that are processed to determine the scattered phase and/or amplitude data. Another non-invasive microwave screening method includes placing a container of an unknown liquid in a tank. The container is separated by a membrane from coupling liquid in the tank. Microwave radiation transmits from a transmitter antenna and scatters from the container and the unknown liquid. One or more receiver antennas convert the microwave radiation into microwave electronic signals. The microwave electronic signals are processed to determine scattered phase and/or amplitude data. A pass result or a fail result is determined based on the scattered phase and/or amplitude data.
    Type: Grant
    Filed: October 30, 2006
    Date of Patent: July 13, 2010
    Assignee: Microwave Imaging Systems Technologies, Inc.
    Inventors: Edward M Godshalk, Timothy Raynolds, Paul M. Meaney, Keith D. Paulsen, Greg Burke
  • Publication number: 20090247847
    Abstract: Optical tomography systems that provide light of multiple distinct wavelengths from a plurality of sources are described. The systems direct light into mammalian tissue, and light from the mammalian tissue is collected at a plurality of reception points. Collected light from each reception point is separated according to its wavelength, and received by a photodetector to produce path attenuation signals representing attenuation along paths between the source locations and the reception points. An image construction system generates a tomographic image of the mammalian tissue from the path attenuation signals. One embodiment of an optical imaging system includes an optical coherence tomography-near infrared probe. The systems and methods may utilize a spectral derivative approach that provides insensitivity to the boundary and boundary artifacts in the signal, thereby improving the quality of the reconstructed images.
    Type: Application
    Filed: April 27, 2006
    Publication date: October 1, 2009
    Applicant: The Trustees of Dartmouth College
    Inventors: Brian William Pogue, Daqing Piao, Keith D. Paulsen, Shudong Jiang, Hamid Dehghani, Heng Xu, Roger Springett, Subhadra Srinivasan
  • Publication number: 20090036766
    Abstract: A microwave imaging system provides superior breast imaging resolution by combining MR microwave absorption and MR-compatible microwave tomography calculations. These techniques may also be supplemented with magnetic resonance elastography techniques, for example, to facilitate quick multispectral imaging.
    Type: Application
    Filed: October 6, 2008
    Publication date: February 5, 2009
    Inventors: Paul M. Meaney, Keith D. Paulsen, John B. Weaver
  • Patent number: 7439736
    Abstract: Magnetic resonance elastography pulse sequences for encoding position and motion of spins, and methods of using the pulse sequences are disclosed. The pulse sequences utilize imaging gradients, comprising a positive lobe and a negative lobe having non-symmetric amplitudes, to encode harmonic or wave motion within a specimen, such as tissue.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: October 21, 2008
    Assignee: The Trustees of Dartmouth College
    Inventors: Paul M. Meaney, Keith D. Paulsen, John B. Weaver
  • Patent number: 7319212
    Abstract: A non-invasive microwave analysis system determines scattered phase and/or amplitude data for a liquid in a container. A tank holds coupling liquid; the system includes a membrane for separating the liquid container from the coupling liquid. A transmitter antenna situated within the coupling liquid transmits microwaves. One or more receiver antennas within the coupling liquid convert microwave radiation that scatters from the liquid in the container into microwave electronic signals. Electronics process the microwave electronic signals to determine scattered phase and/or amplitude values of the microwave radiation.
    Type: Grant
    Filed: October 30, 2006
    Date of Patent: January 15, 2008
    Assignee: Microwave Imaging Systems Technologies, Inc.
    Inventors: Edward M Godshalk, Timothy Raynolds, Paul M. Meaney, Keith D. Paulsen, Greg Burke
  • Patent number: 7164105
    Abstract: Non-invasive microwave analysis systems and methods determine scattered phase data for a liquid in a container. A transmitter antenna situated within coupling liquid separated from the container by a flexible membrane transmits microwaves that scatter from the container and the liquid in the container. One or more receiver antennas within the coupling liquid convert the microwaves into microwave electronic signals that are processed to determine the scattered phase data. Non-invasive microwave analysis systems and methods image a portion of a biological subject. A transmitter antenna situated within coupling liquid separated from the subject by a flexible membrane transmits microwaves that scatter from the container and the subject. One or more receiver antennas within the coupling liquid convert the microwaves into microwave electronic signals that are processed to reconstruct a cross-sectional image of the subject.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: January 16, 2007
    Assignee: Microwave Imaging Systems Technologies, Inc.
    Inventors: Edward M Godshalk, Timothy Raynolds, Paul M. Meaney, Keith D. Paulsen, Greg Burke
  • Publication number: 20040077943
    Abstract: Tomographic imaging of biological tissue is achieved through a microwave imaging system and associated methods. An array of antennas are positioned in an illumination tank to surround biological tissue to be imaged. A liquid coupling medium is placed in the illumination tank, and the biological tissue is immersed in the medium. The array of antennas transmit and receive microwave-frequency RF signals that are propagated through the biological tissue. A signal processor is coupled to the antennas to process a demodulated signal representative of the microwave-frequency RF signal received by one or more of the antennas to produce scattered field magnitude and phase signal projections of the biological tissue. These projections may be used to reconstruct a conductivity and permittivity image across an imaged section of the biological tissue to identify the locations of different tissue types (e.g., normal versus malignant or cancerous) within the biological tissue.
    Type: Application
    Filed: April 4, 2003
    Publication date: April 22, 2004
    Inventors: Paul M. Meaney, Keith D. Paulsen, Margaret W. Fanning, Timothy Reynolds
  • Patent number: 6448788
    Abstract: An improved method and apparatus for microwave imaging of an inhomogeneous target, in particular of biological tissue, compensates for the interactions between active antennae and nonactive antennae. Measured electric field data are processed in magnitude and phase form so that unwrapped phase information may be used directly in the image reconstruction. Initial finite element measurements and calculations are used to determine the perimeter dimensions of the target being examined, resulting in more accurate image reconstructions. An improved regularization technique is a hybrid of a Marquardt regularization scheme with a spatial filtering technique and a Tikhonov regularization scheme. An improved switching matrix enables simultaneous sampling of electric field data from a plurality of receiving antennae.
    Type: Grant
    Filed: May 26, 2000
    Date of Patent: September 10, 2002
    Assignee: Microwave Imaging System Technologies, Inc.
    Inventors: Paul M. Meaney, Keith D. Paulsen, Margaret W. Fanning
  • Patent number: 5841288
    Abstract: The invention provides apparatus and methods for determining electric field properties of an inhomogeneous target. The electric property distribution on a coarse mesh discretization of the target is first estimated; and then the electric field on a fine mesh discretization of the target is computed. The fine mesh has finer discretization than the coarse mesh and is overlapping with the coarse mesh. The electric field is then measured at preselected measurement sites within a homogeneous region external to the target. A Jacobian matrix is also calculated which represents a sensitivity calculation relative to a change in the electric field at selected measurement sites due to a perturbation in the electric property distribution on the coarse mesh. A difference vector is formed between the computed electric field and the measured electric field, and an update vector is added to the electrical property distribution as a function of the difference vector and the Jacobian matrix.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: November 24, 1998
    Assignee: Microwave Imaging System Technologies, Inc.
    Inventors: Paul M. Meaney, Keith D. Paulsen