Patents by Inventor Zuifang Liu

Zuifang Liu 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: 20230375495
    Abstract: A biosensor includes a first base member and a parallel second base member disposed in a parallel and spaced relationship. At least one electrically conductive layer is deposited onto a facing surface of each of the first and second base members at respective first and second conductive regions. The first conductive region includes at least one layer made from a first electrically conductive material and the second conductive region includes at least one layer made from a second electrically conductive material, which is different from the first electrically conductive material. The first electrically conductive material is a precious metal with the first conductive regions of the biosensor defining cofacial electrodes and in which the second electrically conductive layer(s) is configured to electrically connect the cofacial electrodes to a test meter.
    Type: Application
    Filed: May 20, 2022
    Publication date: November 23, 2023
    Inventors: Stuart Phillips, Zuifang Liu, Shona McConachie, Karn Campbell
  • Patent number: 11733198
    Abstract: A method for determining a concentration of an analyte in a fluidic sample is described. A sample is applied to a biosensor including an electrochemical cell having electrodes. A predetermined voltage waveform is applied during at least first and second time intervals. At least first and second current values are measured during the first and second time intervals, respectively. A turning point time is determined during the first time interval at which the measured first current values transition from a first to a second profile. The concentration of analyte in the sample is calculated based on determined turning point time and at least one measured current value. In another example, a physical characteristic of the sample is estimated based on measured current values. The concentration is calculated using a first or second model if the estimated physical characteristic of the sample is in a first or second range, respectively.
    Type: Grant
    Filed: June 14, 2021
    Date of Patent: August 22, 2023
    Assignee: LIFESCAN IP HOLDINGS, LLC
    Inventors: Zuifang Liu, David McColl, Robert Donald, Anna Salgado, Antony Smith
  • Publication number: 20210381998
    Abstract: A method for determining a concentration of an analyte in a fluidic sample is described. A sample is applied to a biosensor including an electrochemical cell having electrodes. A predetermined voltage waveform is applied during at least first and second time intervals. At least first and second current values are measured during the first and second time intervals, respectively. A turning point time is determined during the first time interval at which the measured first current values transition from a first to a second profile. The concentration of analyte in the sample is calculated based on determined turning point time and at least one measured current value. In another example, a physical characteristic of the sample is estimated based on measured current values. The concentration is calculated using a first or second model if the estimated physical characteristic of the sample is in a first or second range, respectively.
    Type: Application
    Filed: June 14, 2021
    Publication date: December 9, 2021
    Inventors: Zuifang Liu, David McColl, Robert Donald, Anna Salgado, Antony Smith
  • Patent number: 11035819
    Abstract: A method for determining a concentration of an analyte in a fluidic sample is described. A sample is applied to a biosensor including an electrochemical cell having electrodes. A predetermined voltage waveform is applied during at least first and second time intervals. At least first and second current values are measured during the first and second time intervals, respectively. A turning point time is determined during the first time interval at which the measured first current values transition from a first to a second profile. The concentration of analyte in the sample is calculated based on determined turning point time and at least one measured current value. In another example, a physical characteristic of the sample is estimated based on measured current values. The concentration is calculated using a first or second model if the estimated physical characteristic of the sample is in a first or second range, respectively.
    Type: Grant
    Filed: June 28, 2018
    Date of Patent: June 15, 2021
    Assignee: LifeScan IP Holdings, LLC
    Inventors: Zuifang Liu, David McColl, Robert Donald, Anna Salgado, Antony Smith
  • Publication number: 20200003722
    Abstract: A method for determining a concentration of an analyte in a fluidic sample is described. A sample is applied to a biosensor including an electrochemical cell having electrodes. A predetermined voltage waveform is applied during at least first and second time intervals. At least first and second current values are measured during the first and second time intervals, respectively. A turning point time is determined during the first time interval at which the measured first current values transition from a first to a second profile. The concentration of analyte in the sample is calculated based on determined turning point time and at least one measured current value. In another example, a physical characteristic of the sample is estimated based on measured current values. The concentration is calculated using a first or second model if the estimated physical characteristic of the sample is in a first or second range, respectively.
    Type: Application
    Filed: June 28, 2018
    Publication date: January 2, 2020
    Inventors: Zuifang LIU, David MCCOLL, Robert DONALD, Anna SALGADO, Antony SMITH
  • Patent number: 10520460
    Abstract: A method for determining a diffusion feature of a fluidic sample using redox reactions in an electrochemical cell that has at least two electrodes, wherein the first electrode has at least one redox mediator at its surface or in close vicinity of its surface, and the second electrode has an electrode surface free of the redox mediator(s) in the beginning of a test, the method comprising: applying an electric potential to a fluidic sample in the electrochemical cell to initiate redox reactions at the two electrode surfaces; measuring current associated with the applied potential as a function of time, and using a measurement point on a transient part of the measured current at or after a turning point and its associated time to determine the diffusion feature.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: December 31, 2019
    Assignee: LifeScan IP Holdings, LLC
    Inventors: Zuifang Liu, Magdalena Gutowska
  • Publication number: 20170241940
    Abstract: A method for determining a diffusion feature of a fluidic sample using redox reactions in an electrochemical cell that has at least two electrodes, wherein the first electrode has at least one redox mediator at its surface or in close vicinity of its surface, and the second electrode has an electrode surface free of the redox mediator(s) in the beginning of a test, the method comprising: applying an electric potential to a fluidic sample in the electrochemical cell to initiate redox reactions at the two electrode surfaces; measuring current associated with the applied potential as a function of time, and using a measurement point on a transient part of the measured current at or after a turning point and its associated time to determine the diffusion feature.
    Type: Application
    Filed: October 26, 2015
    Publication date: August 24, 2017
    Inventors: Zuifang LIU, Magdalena GUTOWSKA
  • Patent number: 9201038
    Abstract: Various embodiments that allow for improved accuracy in the measurement of glucose with a glucose meter and a biosensor, principally, by using pulsed signal inputs to the biosensor and selecting at least one specific pulsed output from the biosensor to determine a glucose concentration that is less affected by interfering chemical substances that might be present in the fluid sample.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: December 1, 2015
    Assignee: LifeScan Scotland Limited
    Inventors: Gavin Macfie, Zuifang Liu
  • Publication number: 20150241378
    Abstract: An electrochemical-based analytical test strip (“TS”) for the determination of an analyte in a bodily fluid sample includes an electrically insulating substrate, a patterned conductor layer disposed over the electrically-insulating substrate and having an analyte working electrode (“WE”), a bare interferent electrode (“IE”) and a shared counter/reference electrode (“CE”). The TS also includes a patterned insulation layer (“PIL”) with an electrode exposure slot configured to expose the WE, IE and CE, an enzymatic reagent layer disposed on the WE and CE, and a patterned spacer layer (“PSL”). The PIL and the PSL define a sample receiving chamber with a sample-receiving opening. The IE and the CE constitute a first electrode pair configured for measurement of an interferent electrochemical response and the WE and the CE constitute a second electrode pair configured for measurement of an analyte electrochemical response. The WE and the IE are electrically isolated from one another.
    Type: Application
    Filed: September 9, 2013
    Publication date: August 27, 2015
    Inventors: Zuifang Liu, Anna Salgado, Gavin Macfie, Damian Baskeyfield, Stuart Phillips
  • Publication number: 20140027312
    Abstract: Various embodiments that allow for improved accuracy in the measurement of glucose with a glucose meter and a biosensor, principally, by using pulsed signal inputs to the biosensor and selecting at least one specific pulsed output from the biosensor to determine a glucose concentration that is less affected by interfering chemical substances that might be present in the fluid sample.
    Type: Application
    Filed: July 24, 2012
    Publication date: January 30, 2014
    Applicant: LifeScan Scotland Limited
    Inventors: Gavin MACFIE, Zuifang LIU
  • Publication number: 20130284609
    Abstract: A nicotinamide adenine dinucleotide (NAD) polymeric coenzyme for use in enzymatic electrochemical-based sensors includes NAD moieties covalently bound as pendent groups to a polymer backbone. An enzymatic electrochemical-based biosensor includes nicotinamide adenine dinucleotide (NAD) polymeric coenzyme, a polymeric electron transfer agent (e.g., polymeric ferrocene) at least one working electrode, and at least one reference electrode.
    Type: Application
    Filed: April 30, 2012
    Publication date: October 31, 2013
    Inventors: Zuifang LIU, Steven Setford, Marco Cardosi
  • Publication number: 20130220835
    Abstract: A biosensor (such as an electrochemical-based analytical test strip configured for the determination of glucose in a whole blood sample) includes a substrate, an electrode disposed on the substrate and a uric acid scavenger layer containing polymeric vinyl-4,6-diamino-1,3,5-triazine (polyVDAT) nanoparticles. Aqueous compositions useful in, for example, the manufacturing of such biosensors include polyVDAT nanoparticles and water with the polyVDAT nanoparticles being present as a dispersion in the water. A method for determining an analyte in a bodily fluid sample containing uric acid includes applying a bodily fluid sample containing uric acid to a biosensor such that the bodily fluid sample comes into contact with a uric acid scavenger layer containing polymeric vinyl-4,6-diamino-1,3,5-triazine (polyVDAT) nanoparticles and determining the analyte based on an electronic signal produced by the biosensor.
    Type: Application
    Filed: February 29, 2012
    Publication date: August 29, 2013
    Inventors: Zuifang LIU, Louise SIMPSON, Marco CARDOSI
  • Publication number: 20120199497
    Abstract: An electrochemical-based analytical test strip for the determination of an analyte (such as glucose) in a bodily fluid sample (e.g., a whole blood sample) includes a substrate, at least one working electrode disposed on the substrate, a sample-soluble enzymatic reagent layer disposed above the working electrode, a diffusion-controlling layer (DCL) disposed between the at least one working electrode and the sample-soluble enzymatic reagent layer; and a sample-receiving chamber. In addition, the sample-soluble enzymatic reagent layer is configured and constituted for operable solubility in a bodily fluid sample applied to the electrochemical-based analytical test strip and received in the sample-receiving chamber and for electrochemical enzymatic reaction with an analyte in the bodily fluid sample.
    Type: Application
    Filed: February 7, 2011
    Publication date: August 9, 2012
    Applicant: LifeScan Scotland Limited
    Inventors: Zuifang Liu, Marco F. Cardosi, Christopher Philip Leach, Scott Sloss
  • Publication number: 20120199498
    Abstract: An electrochemical-based analytical test strip for the determination of an analyte (such as glucose) in a bodily fluid sample (e.g., a whole blood sample) includes an electrically-insulating substrate, at least one working electrode disposed on the electrically-insulating substrate and a graded enzymatic reagent layer disposed on the at least one working electrode. The graded enzymatic reagent layer includes an upper reaction grade that contains an enzyme. The graded enzymatic layer also has a lower spacer grade devoid of the enzyme, the lower spacer grade disposed between the upper reaction grade and the working electrode such that the upper reaction grade is spaced equidistant from the working electrode by the lower spacer grade by a predetermined distance during use of the electrochemical-based analytical test strip.
    Type: Application
    Filed: February 7, 2011
    Publication date: August 9, 2012
    Inventors: Manuel Alvarez-Icaza, Alan McNeilage, Zuifang Liu, Damian Baskeyfield
  • Patent number: 7592151
    Abstract: A redox polymer for use in an electrochemical-based sensor includes a hydrophobic polymer backbone (e.g., a hydrophobic poly(methyl methacrylate) polymer backbone) and at least one hydrophilic polymer arm (such as a hydrophilic oligo(N-vinylpyrrolidinone) polymer arm) attached to the hydrophobic polymer backbone. The redox polymer also includes a plurality of redox mediators (e.g., ferrocene-based redox mediators) attached to the at least one hydrophilic polymer arm.
    Type: Grant
    Filed: October 19, 2007
    Date of Patent: September 22, 2009
    Assignee: Lifescan, Inc.
    Inventors: Zuifang Liu, James Jain Rodgers, Geoffrey Ulue
  • Patent number: 7588670
    Abstract: An enzymatic electrochemical-based sensor includes a substrate and a conductive layer formed from a dried water-miscible conductive ink. The water-miscible conductive ink used to form the conductive layer includes a conductive material, an enzyme, a mediator, and a binding agent and is formulated such that the water-miscible conductive ink is a water-miscible aqueous-based dispersion and the binding agent became operatively water-insoluble upon drying.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: September 15, 2009
    Assignee: LifeScan Scotland Limited
    Inventors: James Iain Rodgers, Zuifang Liu, Alan Watson McNeilage, Margaret MacLennan, James Moffat, Geoffrey Lillie, Michael MacDonald
  • Patent number: 7572356
    Abstract: An electrochemical-based sensor includes an electrode with at least one electrode surface, a film disposed on the electrode surface, and a dialysis membrane disposed on the film. The film includes a redox enzyme and a hydrophilic redox polymer (i.e., a polymer with an attached redox mediator(s)). In addition, the dialysis membrane serves to entrap the redox polymer and redox enzyme in the vicinity of the electrode. Such entrapment is accomplished by employing a redox enzyme and a hydrophilic redox polymer of a sufficiently high molecular weight that they do not pass through the dialysis membrane.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: August 11, 2009
    Assignee: Lifescan Scotland Limited
    Inventors: James Iain Rodgers, Zuifang Liu, Geoffrey Lillie
  • Patent number: 7465380
    Abstract: A water-miscible conductive ink for use in enzymatic electrochemical-based sensors includes a conductive material, an enzyme, a mediator and a binding agent. The conductive material, enzyme, mediator, and binding agent are formulated as a water-miscible aqueous-based dispersion wherein the binding agent becomes operatively water-insoluble upon drying.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: December 16, 2008
    Assignee: Lifescan Scotland, Ltd.
    Inventors: James Iain Rodgers, Zuifang Liu, Alan Watson McNeilage, Margaret MacLennan, James Moffat, Geoffrey Lillie, Michael MacDonald
  • Patent number: 7429630
    Abstract: A redox polymer for use in an electrochemical-based sensor includes a hydrophobic polymer backbone (e.g., a hydrophobic poly(methyl methacrylate) polymer backbone) and at least one hydrophilic polymer arm (such as a hydrophilic oligo(N-vinylpyrrolidinone) polymer arm) attached to the hydrophobic polymer backbone. The redox polymer also includes a plurality of redox mediators (e.g., ferrocene-based redox mediators) attached to the at least one hydrophilic polymer arm.
    Type: Grant
    Filed: May 4, 2006
    Date of Patent: September 30, 2008
    Assignee: Lifescan Scotland Limited
    Inventors: Zuifang Liu, James Jain Rodgers, Geoffrey Lillie
  • Patent number: 7351770
    Abstract: Ionic hydrophilic high molecular weight redox polymers for use in enzymatic electrochemical-based sensors include a hydrophilic polymer (such as a hydrophilic polymer backbone) with ionic portions (e.g., cationic monomers incorporated in the hydrophilic polymer backbone) and a plurality of attached redox mediators. The redox mediators can be, for example, covalently attached to the hydrophilic polymer in a pendant manner. An exemplary cationic hydrophilic high molecular weight redox polymer is synthesized by co-polymerization of a hydrophilic acrylamide monomer, [2-(acryloyloxy)ethyl]trimethyl ammonium chloride and vinyl ferrocene.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: April 1, 2008
    Assignee: Lifescan, Inc.
    Inventors: Zuifang Liu, James Iain Rodgers, Geoffrey Lillie, Marco Fabio Cardosi