Patents by Inventor Douglas A. Christensen

Douglas A. Christensen 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: 20240344469
    Abstract: A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.
    Type: Application
    Filed: June 24, 2024
    Publication date: October 17, 2024
    Inventors: Alexander Konrad Fuhrman, Ryan Douglas Hayes, Andrew Jon Ellsworth, Cord Miller Christensen, David Mark Sabo, Derek Robert Kvenvold
  • Patent number: 12055076
    Abstract: A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.
    Type: Grant
    Filed: June 15, 2023
    Date of Patent: August 6, 2024
    Assignee: Arctic Cat Inc.
    Inventors: Alexander Konrad Fuhrman, Ryan Douglas Hayes, Andrew Jon Ellsworth, Cord Miller Christensen, David Mark Sabo, Derek Robert Kvenvold
  • Patent number: 12044470
    Abstract: A system and method for recovering high-quality biomethane (RNG) from biogas sources is provided. The gas stream is compressed and liquids are separated from the gas stream at elevated pressure and reduced temperature. The compressing is performed using a plurality of compressors operating in parallel with common control set points. The system and method improve upon conventional practices and yield a biomethane product which meets strict gas pipeline quality specifications. Additionally, the system and method are an improvement to the overall methane recovery efficiency for biogas processing facilities.
    Type: Grant
    Filed: February 14, 2024
    Date of Patent: July 23, 2024
    Assignee: WM INTELLECTUAL PROPERTY HOLDINGS, L.L.C.
    Inventors: Derek Christensen, Jon Denault, Greg Miles, Keith Ott, Douglas Lee Palmer, Jr.
  • Patent number: 11445997
    Abstract: Systems and methods for accurately measuring changes in biomarker sensitive hydrogel volume and shape due to exposure to various biomarkers include a system for identifying one or more dimensional changes in a biomarker sensitive hydrogel positioned within an in vivo environment. The system includes a biomarker sensitive hydrogel positioned within an in vivo environment and configured to dimensionally change in response to interaction with predefined biomarkers. The system additionally includes an ultrasound transducer for locating and identifying one or more characteristics of the biomarker sensitive hydrogel and a computer system in electrical communication with the ultrasound transducer. The computer system is configured to receive characteristics of the biomarker sensitive hydrogel from the ultrasound transducer and determine dimensional changes of the biomarker sensitive hydrogel based on the received characteristics.
    Type: Grant
    Filed: September 1, 2017
    Date of Patent: September 20, 2022
    Assignees: UNIVERSITY OF UTAH RESEARCH FOUNDATION, SENTIOMED, INC.
    Inventors: Mahender nath Avula, Douglas A. Christensen, Navid Farhoudi, Stan Kanarowski, Julia Koerner, Jules John Magda, Rami Sami Marrouche, Christopher F. Reiche, Florian Solzbacher, Michael David Sorenson
  • Publication number: 20190192113
    Abstract: Systems and methods for accurately measuring changes in biomarker sensitive hydrogel volume and shape due to exposure to various biomarkers include a system for identifying one or more dimensional changes in a biomarker sensitive hydrogel positioned within an in vivo environment. The system includes a biomarker sensitive hydrogel positioned within an in vivo environment and configured to dimensionally change in response to interaction with predefined biomarkers. The system additionally includes an ultrasound transducer for locating and identifying one or more characteristics of the biomarker sensitive hydrogel and a computer system in electrical communication with the ultrasound transducer. The computer system is configured to receive characteristics of the biomarker sensitive hydrogel from the ultrasound transducer and determine dimensional changes of the biomarker sensitive hydrogel based on the received characteristics.
    Type: Application
    Filed: September 1, 2017
    Publication date: June 27, 2019
    Inventors: Mahender nath Avula, Douglas A. Christensen, Navid Farhoudi, Stan Kanarowski, Julia Koerner, Jules John Magda, Rami Sami Marrouche, Christopher F. Reiche, Florian Solzbacher, Michael David Sorenson
  • Publication number: 20190029650
    Abstract: A technology is described for multipoint tissue elastic property measurement. An example method (700) 700 includes generating a treatment map (710) of an anatomical region that shows focal points within the anatomical region to be exposed to Focused Ultrasound (FUS) pulses; acquiring a reference MR-ARFI image (720) of the anatomical region containing the focal points using the treatment map; acquiring an active MR-ARFI image (730) for each of the focal points in the anatomical region during exposure of the focal points to the FUS pulses using the treatment map; interleaving the reference MR-ARFI image and active MR-ARFI images (740) to create a combined image of the anatomical region and the focal points; and calculating a tissue displacement measurement (750) for the focal points exposed to the simultaneous and/or rapidly interleaved FUS pulses using the combined image of the anatomical region and the focal points exposed to the simultaneous FUS pulses.
    Type: Application
    Filed: January 10, 2017
    Publication date: January 31, 2019
    Inventors: Dennis Parker, Allison Payne, Joshua De Bever, Douglas Christensen
  • Patent number: 7819810
    Abstract: An apparatus, method and system for cannulation of blood vessels. The apparatus comprises a sensor assembly including two linear transducer arrays oriented perpendicular to each other to form a “T” shape to provide ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The sensor assembly may have graphic markings on an exterior surface thereof to facilitate orientation of the sensor assembly on the patient and guidance of a needle toward a desired target vessel during the cannulation procedure. The sensor assembly may also include an associated structure to cooperate with a reference location element to place, align and secure the sensor assembly to the patient's skin at a desired location.
    Type: Grant
    Filed: August 3, 2004
    Date of Patent: October 26, 2010
    Assignee: Inceptio Medical Technologies, LC
    Inventors: Bradley J. Stringer, Gary A. Simmons, Douglas A. Christensen, Shayne Messerly, Cameron P. Ford, Robert W. Evensen
  • Patent number: 7537734
    Abstract: A composite waveguide for evanescent sensing in fluorescent binding assays comprising a substrate layer having one or more thin-film waveguide channels deposited thereon. Binding molecules having the property of binding with specificity to an analyte are immobilized on the surface of the thin-film channels. In preferred embodiments, the composite waveguide includes integral light input coupling means adapted to the thin-film channels. Light coupling means may include a grating etched into the substrate prior to deposition of the thin film, or a waveguide coupler affixed to the upper surface of the thin film. The waveguide coupler has an input waveguide of high refractive index which receives the laser light through one end, propagating it by total internal reflection. Propagated light is coupled evanescently into the thin film across a spacer layer of precise thickness with a lower index of refraction than that of the input waveguide or the thin-film waveguide.
    Type: Grant
    Filed: October 10, 2001
    Date of Patent: May 26, 2009
    Assignee: University of Utah Research Foundation
    Inventors: W. Monty Reichert, James N. Herron, Douglas A. Christensen, Hsu-Kun Wang
  • Patent number: 7214191
    Abstract: An apparatus, method, system, component kit and protective sheath for cannulation of blood vessels are disclosed. The apparatus comprises a sensor assembly to provide ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The sensor assembly may have graphic markings on an exterior surface thereof to facilitate orientation of the sensor assembly on the patient and guidance of a needle towards a desired target vessel during the cannulation procedure. The sensor assembly may also include associated structure to cooperate with a reference location element to place, align and secure the sensor assembly to the patient's skin at a desired location.
    Type: Grant
    Filed: June 21, 2004
    Date of Patent: May 8, 2007
    Assignee: Inceptio Medical Technologies, L.C.
    Inventors: Bradley J. Stringer, Gary A. Simmons, Douglas A. Christensen, Shayne Messerly, Cameron P. Ford, Robert W. Evensen
  • Publication number: 20070023119
    Abstract: The present invention is an apparatus for forming a fabric for an architectural opening covering. The apparatus comprises a joining section, an accumulator, a cutting station, and a stacker. The joining section is configured to join together first, second, third and fourth material strips into a fabric strip. The accumulator is configured to accumulate the fabric strip upon leaving the joining section. The cutting station is configured to sever the fabric strip into an upstream fabric strip and a first downstream fabric strip. The stacker is configured to join the first downstream fabric strip with a second downstream fabric strip to form the fabric.
    Type: Application
    Filed: July 18, 2006
    Publication date: February 1, 2007
    Applicant: Hunter Douglas Inc.
    Inventors: Kevin Dann, Ralph Jelic, Michael Siebenaller, Thomas Sevcik, William Teter, Joseph Kovach, Douglas Christensen
  • Publication number: 20060293597
    Abstract: A transmission wave field imaging method, comprising the transmission of an incident wave field into an object, the incident wave field propagating into the object and, at least, partially scattering. Also includes the measuring of a wave field transmitted, at least in part, through an object to obtain a measured wave field, the measured wave field based, in part, on the incident wave field and the object. Additionally, the processing of the measured wave field utilizing a parabolic approximation reconstruction algorithm to generate an image data set representing at least one image of the object.
    Type: Application
    Filed: May 17, 2006
    Publication date: December 28, 2006
    Inventors: Steven Johnson, David Borup, James Wiskin, Michael Berggren, Frank Natterer, F. Wubbeling, Yongzhi Zhang, Douglas Christensen, Frank Stenger
  • Patent number: 7022515
    Abstract: Methods and apparatus for evanescent light fluoroimmunoassays are disclosed. The apparatus employs a planar waveguide and optionally has multi-well features and improved evanescent field intensity. The preferred biosensor and assay method have the capture molecules immobilized to the waveguide surface by site-specific coupling chemistry. Additionally, the coatings used to immobilize the capture molecules provide reduced non-specific protein adsorption.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: April 4, 2006
    Assignee: University of Utah Research Foundation
    Inventors: James N. Herron, Douglas A. Christensen, Karin D. Caldwell, Vera Janatová, Shao-Chie Huang, Hsu-Kun Wang
  • Patent number: 6979567
    Abstract: Methods and apparatus for evanescent light fluoroimmunoassays are disclosed. The apparatus employs a planar waveguide with an integral semicylindrical lens, and has multi-analyte features and calibration features, along with improved evanescent field intensity. A preferred embodiment of the biosensor and assay method has patches of capture molecules, each specific for a different analyte disposed adjacently within a single reservoir. The capture molecules are immobilized to the patches on the waveguide surface by site-specific coupling of thiol groups on the capture molecules to photo-affinity crosslinkers, which in turn are coupled to the waveguide surface or to a nonspecific binding-resistant coating on the surface. The patches of different antibodies are produced by selectively irradiating a portion of the waveguide surface during the process of coupling the photo-affinity crosslinkers, the selective irradiation involving a mask, a laser light source, or the like.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: December 27, 2005
    Assignee: BioCentrex, LLC
    Inventors: James N. Herron, Douglas A. Christensen, Hsu-Kun Wang, Karin Caldwell, Vera Janatová, Shao-Chie Huang
  • Patent number: 6911344
    Abstract: A step-gradient composite waveguide for evanescent sensing in fluorescent binding assays comprises a thick substrate layer having one or more thin film waveguide channels deposited thereon. In one embodiment, the substrate is silicon dioxide and the thin film is silicon oxynitride. Specific binding molecules having the property of binding with specificity to an analyte are immobilized on the surface of the thin film channels. In preferred embodiments, the composite waveguide further includes light input coupling means integrally adapted to the thin film channels. Such light coupling means can be a grating etched into the substrate prior to deposition of the thin film, or a waveguide coupler affixed to the upper surface of the thin film. The waveguide coupler has a thick input waveguide of high refractive index which receives the laser light through one end and propagates it by total internal reflection.
    Type: Grant
    Filed: November 3, 1998
    Date of Patent: June 28, 2005
    Assignee: BioCentrex, LLC
    Inventors: W. Monty Reichert, James N. Herron, Douglas A. Christensen, Hsu-Kun Wang, Jacob D. Durtschi
  • Publication number: 20050020919
    Abstract: An apparatus, method and system for cannulation of blood vessels. The apparatus comprises a sensor assembly including two linear transducer arrays oriented perpendicular to each other to form a “T” shape to provide ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes and optionally determine flow direction within the at least one blood vessel. The sensor assembly may be disposed within a graphically marked cover to facilitate orientation of the sensor assembly on the patient and guidance of a needle towards a desired target vessel during the cannulation procedure. The cover may also include associated structure to cooperate with a reference location element to place, align and secure the sensor assembly to the patient's skin at a desired location.
    Type: Application
    Filed: August 3, 2004
    Publication date: January 27, 2005
    Inventors: Bradley Stringer, Gary Simmons, Douglas Christensen, Shayne Messerly, Cameron Ford, Robert Evensen
  • Publication number: 20040236224
    Abstract: An apparatus, method and system for cannulation of blood vessels. The apparatus comprises a sensor assembly including two linear transducer arrays oriented perpendicular to each other to form a “T” shape, to provide ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The sensor assembly may be disposed within an elongated, flexible, protective sheath and secured to a frame to facilitate orientation of the sensor assembly on the patient and guidance of a needle towards a desired target vessel during the cannulation procedure. The sensor assembly may also include associated structure to cooperate with a reference location element to place, align and secure the sensor assembly to the patient's skin at a desired location.
    Type: Application
    Filed: June 21, 2004
    Publication date: November 25, 2004
    Inventors: Bradley J. Stringer, Gary A. Simmons, Douglas A. Christensen, Shayne Messerly, Cameron P. Ford, Robert W. Evensen
  • Patent number: 6755789
    Abstract: An apparatus, method and system for cannulation of blood vessels. The apparatus comprises a sensor assembly including two linear transducer arrays oriented perpendicularly to each other to form a “T” shape to provide substantially simultaneous ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The apparatus may also include one or more Doppler transducer elements to transmit and receive one or more Doppler beams at an incident angle beneath one of the transducer arrays and in alignment therewith to determine blood flow direction and velocity within the at least one blood vessel. The sensor assembly may be disposed within an elongated, flexible, protective sheath and secured to a graphically marked cover to facilitate orientation of the sensor assembly on the patient and guidance of a needle towards a desired target vessel during the cannulation procedure.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: June 29, 2004
    Assignee: Inceptio Medical Technologies, LLC
    Inventors: Bradley J. Stringer, Gary A. Simmons, Douglas A. Christensen, Shayne Messerly, Cameron P. Ford, Robert W. Evensen
  • Patent number: 6611634
    Abstract: Improvements in a biosensor are disclosed. A biosensor includes a waveguide, at least a portion of which is substantially planar. One or more reservoirs may be formed adjacent to a chemistry-bearing surface of the waveguide. The biosensor may include a gasket to form a seal between the waveguide and side walls of the reservoir. A sample solution may be introduced into the reservoir or otherwise onto the surface of a waveguide through an input port. Waveguides of varying composition (e.g., plastic, quartz, glass, or other suitable waveguide materials) may be used in the biosensor. Also disclosed is a sled-shaped waveguide, which includes a planar portion and a lens at an end thereof and angled relative thereto for coupling light into the waveguide.
    Type: Grant
    Filed: March 11, 2002
    Date of Patent: August 26, 2003
    Assignee: University of Utah Research Foundation
    Inventors: James N. Herron, Douglas A. Christensen, Victor A. Pollak, Richard D. McEachern, Eric M. Simon
  • Publication number: 20030149366
    Abstract: An apparatus, method and system for cannulation of blood vessels. The apparatus comprises a sensor assembly including two linear transducer arrays oriented perpendicular to each other to form a “T” shape, to provide substantially simultaneous ultrasound images of at least one blood vessel in a portion of a patient's body in two perpendicular planes. The apparatus may also include one or more Doppler transducer elements to transmit and receive one or more Doppler beams at an incident angle beneath one of the transducer arrays and in alignment therewith to determine blood flow direction and velocity within the at least one blood vessel. The sensor assembly may be disposed within an elongated, flexible, protective sheath and secured to a graphically marked cover to facilitate orientation of the sensor assembly on the patient and guidance of a needle towards a desired target vessel during the cannulation procedure.
    Type: Application
    Filed: February 5, 2002
    Publication date: August 7, 2003
    Inventors: Bradley J. Stringer, Gary A. Simmons, Douglas A. Christensen, Shayne Messerly, Cameron P. Ford, Robert W. Evensen
  • Patent number: RE39772
    Abstract: Improvements in a biosensor of the type having reservoirs or wells for analyzing a biological liquid are disclosed. A biosensor (190) includes a waveguide (164) placed between a plurality of members such as plates (100, 186), at least one of the members (100) being formed to define the walls (132, 134, 136) of the reservoirs where the liquid is biologically analyzed. The walls of the reservoirs are made of an inert, opaque material such as a metal. Although the biosensor may include a gasket (162), the gasket is associated with the members and waveguide in such a way (e.g. by recessing the gasket into a channel formed into a metal plate) so that the gasket does not form any significant portion of the reservoir wall. Waveguides of varying composition (e.g. plastic, quartz or glass) may be associated with the members to form the biosensor. The metal plate of the biosensor has input and output ports for infusing, draining, or oscillating the liquid to be analyzed in the reaction reservoir.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: August 14, 2007
    Assignee: University of Utah Research Foundation
    Inventors: James N. Herron, Douglas A. Christensen, Victor A. Pollack, Richard D. McEachern, Eric M. Simon