Patents Examined by T. Tung
  • Patent number: 6592746
    Abstract: A sensor probe is disclosed which can measure the hydrogen peroxide content of a single sample using two oxygen sensors whose electrodes are encased in defined membranes. The oxygen reference sensor is encased in a hydrophobic membrane which prevents the transport of hydrogen peroxide or electrochemical poisons or interferents and isolates the electrodes and an electrolyte fluid surrounding the electrodes from the sample fluid. The hydrogen-peroxide-generated oxygen (HPGO) sensor is also is encased in such a hydrophobic membrane, but has in series with and distally of the hydrophobic membrane a hydrophilic membrane which contains an immobilized enzyme such as catalase, peroxidase or other enzymes of a family which catalyzes the reaction of hydrogen peroxide to oxygen and water. At the HPGO sensor, the hydrogen peroxide is catalyzed to oxygen by the enzyme so that the HPGO sensor measures an enhanced concentration of oxygen relative to the oxygen reference sensor.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: July 15, 2003
    Assignee: The Regents of the University of California
    Inventors: Geert W. Schmid-Schoenbein, Dale A. Baker, David Gough
  • Patent number: 6592731
    Abstract: A low cost amperometric oxygen sensor which utilizes a plurality of oxygen ion conductor layers interposed between a plurality of oxygen-porous electrode layers is provided. Oxygen from a sample gas enters the sensor at porous cathode electrodes, is pumped through the ion conductor layers, and exits through the anode electrodes. The amperometric current generated is representative of the partial pressure of oxygen in the sample gas. In accordance with one embodiment of the present invention, an amperometric oxygen sensor is provided for determining the oxygen partial pressure of a gas. The sensor comprises a sensor body defined by a plurality of oxygen-porous electrode layers and at least one oxygen ion conductor layer. The plurality of oxygen-porous electrode layers include at least one cathode layer and at least one anode layer. Each of the cathode layers define first and second major cathode surfaces and each of the anode layers defining first and second major anode surfaces.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: July 15, 2003
    Assignee: CeramPhysics, Inc.
    Inventor: William N. Lawless
  • Patent number: 6592732
    Abstract: In a maltilayer exhaust gas component sensor for measuring NOX (nitrogen oxide) and HC (hydrocarbon), the reliability and the productivity are improved without degrading the detecting sensitivity. A gas sensing portion is formed by laminating porous solid electrolyte layers having gas permeability together with an electrode protecting film, porous electrodes having catalytic activity, a porous electric insulating layer and a closely-compacted (dense) solid electrolyte layer, and by placing a heater as a temperature control means in contact with or near the laminated layer body.
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: July 15, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masahiro Komachiya, Seikou Suzuki
  • Patent number: 6589410
    Abstract: The invention presents a hydrocarbon sensor excellent in yield and high in detection precision. To achieve the object, the invention includes a solid electrolyte layer (1) contained barium-cerium oxide, a pair of electrodes, cathode (2) and anode (3), provided on the solid electrolyte layer (1), a ceramic substrate (4) having a coefficient of thermal expansion nearly same as that of the solid electrolyte layer (1), and a heater (7) provided on the ceramic substrate (4), in which the solid electrolyte layer (1) and ceramic substrate (4) are bonded to each other.
    Type: Grant
    Filed: September 26, 2000
    Date of Patent: July 8, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Rihito Shoji, Takashi Tamai, Noboru Taniguchi
  • Patent number: 6589409
    Abstract: An objective gas to be measured is introduced into first and second chambers which are connected via a diffusion resistive passage. A first electrochemical cell is provided in the first chamber for pumping in and out oxygen in accordance with an applied voltage. A second electrochemical cell is provided in the second chamber and responsive to application of a predetermined voltage for generating a sensor current representing a specific gas concentration in the objective gas. The first electrochemical cell is located between the first chamber and a reference gas chamber so that oxygen pumping in and out operation can be performed between the first chamber and the reference gas chamber.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: July 8, 2003
    Assignees: Denso Corporation, Nippon Soken, Inc.
    Inventors: Akira Miyashita, Akio Tanaka, Toshitaka Saito, Keigo Mizutani
  • Patent number: 6585872
    Abstract: Disclosed herein is a gas sensor having a small amount of lead oxide incorporated into an inner electrode and an outer electrode, and a method for depositing the lead oxide. The lead oxide is applied in an amount sufficient to effectuate consistent performance during sensor break-in. Lead oxide is transferred to the electrodes of the sensor element during the fabrication process by exposing the sensor element to glass having a known lead content during a heating step. Lead oxide from the glass is vaporized and deposited on the electrodes in the form of lead oxide. The deposited lead oxide is incorporated into the electrodes of the sensor element. The lead oxide reduces performance irregularities thereby improving performance during the initial use of the gas sensor.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: July 1, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Matthew J. Donelon, Paul Kikuchi, Marsha E. Nottingham
  • Patent number: 6582587
    Abstract: Numerical techniques such as the finite element method (FEM) are used to model the current and voltage distribution in concrete structures such as bridges. The geometric arrangement of groundbeds and the ideal locations for the electrical contacts vis-a-vis the geometry of the bridge and the rebars can thereby be predicted and a cathodic protection (CP) system for the bridge designed. A magnetic sensor is used to sense the magnetic field generated by the CP current, and a voltmeter or an oscilloscope to measure the output of the magnetic sensor. A current interrupter is also used to interrupt the CP current at the source. The current is mapped by placing the magnetic sensor on or above the concrete surface. By moving the sensor from one location to another, the current is mapped over the entire structure. To achieve uniform distribution over the entire structure, an “expert” CP system controlled by a variety of current and environmental sensors and a dedicated microprocessor is described.
    Type: Grant
    Filed: February 13, 1997
    Date of Patent: June 24, 2003
    Assignee: The Johns Hopkins University
    Inventors: Rengaswamy Srinivasan, Periya Gopalan, Paul R. Zarriello
  • Patent number: 6579436
    Abstract: A gas sensor, comprising an oxygen pump cell with a first pump electrode and a second pump electrode disposed on opposite sides of a first solid electrolyte layer and a second pump electrode. The sensor also comprises an emf cell with an emf electrode and a reference gas electrode disposed on opposite sides of a second solid electrolyte layer. The emf electrode is disposed in fluid communication to the second pump electrode. A via hole is disposed through the first solid electrolyte layer, such that the first pump electrode is in fluid communication with the second pump electrode. A protective insulating layer, having a passage for gas to be sensed, is disposed in contact with the first pump electrode. A first insulating layer, having a conduit, is disposed in contact with the emf electrode. A second insulating layer, having an air channel, is disposed in contact with the reference gas electrode. A heater is disposed in thermal communication with the emf cell.
    Type: Grant
    Filed: December 18, 2000
    Date of Patent: June 17, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Da Yu Wang, Paul C. Kikuchi, Walter T Symons, Kaius K. Polikarpus, Larry M. Oberdier
  • Patent number: 6579435
    Abstract: A gas sensor is disclosed comprising an oxygen pump cell having at least one exterior pump electrode and at least one interior pump electrode disposed on opposite sides of a first solid electrolyte layer. An emf cell having a first and second emf electrodes and first and second reference gas electrodes are disposed on opposite sides of a second solid electrolyte layer. At least one insulating layer is in contact with the first and second emf electrodes. At least one via hole is disposed through the first solid electrolyte layer. At least one air channel is disposed through at least one insulating layer. An air vent is disposed in at least one insulating layer in contact with the first and second reference gas electrodes. A heater is disposed in thermal communication with the sensor. And at least five electrical leads are in electrical communication with said sensor. A method of using a gas sensor is also disclosed.
    Type: Grant
    Filed: December 18, 2000
    Date of Patent: June 17, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Da Yu Wang, Paul C. Kikuchi, Walter T. Symons, Kaius K. Polikarpus, Larry M. Oberdier
  • Patent number: 6579440
    Abstract: A reference junction for a reference half-cell, the reference junction including an ion-barrier membrane and being sized and shaped for removable receipt within a receptacle of a reference half-cell housing. The reference junction may be included in an electrochemical potential measurement sensor for use in making pH, other selective ion activity, oxidation-reduction potential, and other electrochemical potential measurements.
    Type: Grant
    Filed: June 19, 2001
    Date of Patent: June 17, 2003
    Assignee: Invensys Systems, Inc.
    Inventors: John P. Connelly, Michael M. Bower
  • Patent number: 6579432
    Abstract: An electrochemical sensor for detection of a gas in an atmosphere containing the gas. The sensor has a housing having an electrochemical gas sensor with an electrolyte and at least two electrodes, one electrode being a gas sensing electrode. The housing has an orifice between the sensing electrode and the atmosphere for transmission of gas from the atmosphere to the sensing electrode, the orifice being protected by a hydrophobic membrane, and connected to at least two radial channels extending from the orifice. Each of the radial channels is connected to a common channel, such that gas communication from the atmosphere through the orifice to the sensing electrode is through the common channel and the radial channels, in addition to the covering membrane if the membrane is gas permeable.
    Type: Grant
    Filed: September 13, 2001
    Date of Patent: June 17, 2003
    Inventor: John Mallory
  • Patent number: 6576101
    Abstract: A sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 &mgr;L. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable. The amount of analyte can be determined by coulometry. One particular coulometric technique includes the measurement of the current between the working electrode and a counter or reference electrode at two or more times. The charge passed by this current to or from the analyte is correlated with the amount of analyte in the sample.
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: June 10, 2003
    Assignee: TheraSense, Inc.
    Inventors: Adam Heller, Benjamin J. Feldman, James Say, Mark S. Vreeke
  • Patent number: 6576105
    Abstract: The present invention provides a unique method and means for detecting pteridines in biological samples using the novel combination of capillary electrophoresis (CE) and laser-induced fluorescence detection (LIF). The method is effective in detecting eight pteridine compounds at very low detection limits of less than about 1×10−10 M. The method allows for the detection of pteridines for various purposes involving metabolism and function investigation, including cancer monitoring and precancer screening.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 10, 2003
    Assignee: Truman State University
    Inventor: Yinfa Ma
  • Patent number: 6572826
    Abstract: Chemically sensitive sensors, suitable for detecting analytes in fluids (in gaseous or liquid phase), wherein the chemically sensitive sensors comprise a chemically sensitive probe, which comprises one or a blend of several arylene alkenylene oligomers.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: June 3, 2003
    Assignee: OligoSense NV
    Inventors: Michaël De Wit, Emmanuel Vanneste, Frank Blockhuys, Gunter Verreyt, Wim Tachelet, Luc J. Nagels, Herman J. Geise
  • Patent number: 6569305
    Abstract: The present invention is a method for injection and stacking of analytes in high salt samples. This stacking method works with both pressure injection or electrokinetic injection. The ability to stack analytes with electrokinetic injection allows the translation of high-salt stacking from the capillary to the microchip format.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: May 27, 2003
    Inventors: James Palmer, James P. Landers
  • Patent number: 6569304
    Abstract: The invention relates to reference electrodes for use in voltammetric measuring chains for oxidative as well as reductive detection of analytes, which are open with respect to the measuring medium. A metal-containing phthalocyanine or a metalloporphyrin is employed as potential-determining electrode material for reference electrodes of the invention used in oxidative detection. A fourth period metal, preferably copper, and a salt of said metal is employed as potential-determining electrode material for reference electrodes of the invention used in reductive detection. The potential-determining electrode material is coated as a layer or component of a layer on a planar support. The open reference electrodes according to the invention are particularly suited for voltammetric chemo- or biosensors having a planar structure.
    Type: Grant
    Filed: April 12, 2000
    Date of Patent: May 27, 2003
    Assignee: SensLab Gesellschaft zur Entwicklung und Herstellung bioelektrochemischer Sensoren mbH
    Inventors: Bernd Gründig, Holm Kopinke, Sybille Wollermann
  • Patent number: 6569686
    Abstract: This invention relates to a method for the determination of solubility of a compound and an analytical device for carrying out said method. The basic method involves determining solubility of a compound by measuring the UV spectrum of a reference solution of the compound, under conditions avoiding or suppressing precipitation, and comparing it to the UV spectrum of a saturated sample solution of the compound. Variations of the basic method include: (a) making reference solutions either by dilution of the sample solution to the point where precipitation is avoided, or making reference solutions by adding a water-miscible cosolvent to the sample solution so that precipitation is suppressed, and comparing the UV absorbances of the compound under reference conditions to the compound in a saturated solution, (b) determining the true aqueous solubility from the effect on the pKa that results from dissolving the compound in an aqueous solution containing some DMSO (typically 0.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: May 27, 2003
    Assignee: Pion, Inc.
    Inventors: Alex Avdeef, Konstantin L. Tsinman
  • Patent number: 6569303
    Abstract: A method of adjusting an output of a gas sensor element is provided. The gas sensor element includes a lamination of a solid electrolyte body, a target gas-exposed electrode, a reference gas-exposed electrode, and a diffused resistance layer in which a target gas to be measured diffuses. The target gas-exposed electrode is disposed on a first surface of the solid electrolyte body exposed to the target gas. The reference gas-exposed electrode is disposed on a second surface of the solid electrolyte body exposed to a reference gas. The diffused resistance layer is disposed on the first surface of the solid electrolyte body. The target gas-exposed electrode and the reference gas-exposed electrode produce a sensor output. The adjustment of the sensor output is achieved by decreasing a diffusion length of the target gas in the diffused resistance layer as a function of a quantity of the sensor output to be adjusted by, for example, removing a portion of the diffused resistance layer.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: May 27, 2003
    Assignee: Denso Corporation
    Inventors: Keigo Moriguchi, Makoto Nakae
  • Patent number: 6569296
    Abstract: A grid anode for cathodic protection of steel reinforced concrete structures formed of multiple valve metal strips including multiple electric current-carrying valve metal strips. Valve metal strip grid anodes without an electrocatalytic metal surface can be used in a cathodic protection system operated at an anode current density up to about 20 milliamps per square foot. Composite anodes having an electrocatalytic metal coating are useful at higher anode current densities.
    Type: Grant
    Filed: January 30, 1996
    Date of Patent: May 27, 2003
    Inventors: John William Burgher, Dennis F. Dong, Richard Eric Loftfield
  • Patent number: 6565723
    Abstract: An exhaust gas sensor element has an electrolyte body, an inner electrode disposed on an inner surface of the electrolyte body, an outer electrode disposed on an outer surface of the electrolyte body, and a ground isolating coating disposed over the outer electrode. The ground isolating coating is typically alumina and extends from an active end of the electrolyte body toward an opposing end of the electrolyte body. The invention also includes a method for constructing a gas sensor element, the steps of which comprise forming an electrolyte body having an inner surface and an outer surface, applying an electrode ink to the inner surface to form an inner electrode and to the outer surface to form an outer electrode, and depositing a combination poison resistant/ground isolating coating, which is typically alumina, over the outer surface such that the combination coating extends from an active end of the electrolyte body toward an opposing end of the electrolyte body.
    Type: Grant
    Filed: December 4, 2000
    Date of Patent: May 20, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Blaine R. Danley, Thomas G. Line