Patents by Inventor Narayanan Ramamurthy

Narayanan Ramamurthy 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: 8801918
    Abstract: Methods and devices for point of care determination of heparin concentration in blood are described. Cartridges including protamine ion sensitive electrodes (ISEs) and reference electrodes and systems for automatically determining heparin concentration in the cartridges are provided. Some systems add blood to a protamine bolus sufficient to bind all heparin, leaving excess protamine. The excess protamine concentration can be determined by measuring the initial slope of the electrode potential rate of change, and comparing the slope to known protamine concentration slope values In some cartridges, an oscillating pressure source moves the blood-protamine mixture back and forth across the protamine ISE. Some systems also use a second blood sample having the heparin removed or degraded to create a blank reference sample. Protamine ISEs can include polyurethane polymer, DNNS ionophore, and NPOE plasticizer.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: August 12, 2014
    Assignee: Medtronic, Inc.
    Inventors: Wei Qin, Daniel S. Cheek, Christopher Hobot, Kelvin Bonnema, Randy Meyer, Douglas Dean Nippoldt, Vitally G. Sitko, Qingshan (Sam) Ye, Narayanan Ramamurthy
  • Patent number: 8158259
    Abstract: The invention is directed to optical sensors for measuring clinically relevant analytes, their methods of manufacture, and their various uses. In an effort to develop a dry calibration method for the optical sensors of the invention it is discovered that water content inside or in the immediate vicinity of a such a sensor can have a major impact on fluorescence intensity (i.e., a sensor's response in the dry state). Thus, one of the objectives of the invention is the elimination of the bias of sensor responses measured at different humidity environments.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: April 17, 2012
    Assignee: Opti Medical Systems
    Inventors: Narayanan Ramamurthy, Huarui He, Chao Lin
  • Publication number: 20100181210
    Abstract: Methods and devices for point of care determination of heparin concentration in blood are described. Cartridges including protamine ion sensitive electrodes (ISEs) and reference electrodes and systems for automatically determining heparin concentration in the cartridges are provided. Some systems add blood to a protamine bolus sufficient to bind all heparin, leaving excess protamine. The excess protamine concentration can be determined by measuring the initial slope of the electrode potential rate of change, and comparing the slope to known protamine concentration slope values In some cartridges, an oscillating pressure source moves the blood-protamine mixture back and forth across the protamine ISE. Some systems also use a second blood sample having the heparin removed or degraded to create a blank reference sample. Protamine ISEs can include polyurethane polymer, DNNS ionophore, and NPOE plasticizer.
    Type: Application
    Filed: March 29, 2010
    Publication date: July 22, 2010
    Inventors: Wei Qin, Daniel S. Cheek, Christopher Hobot, Kelvin Bonnema, Randy Meyer, Douglas Dean Nippoldt, Vitally G. Sitko, Qingsham (Sam) Ye, Narayanan Ramamurthy
  • Patent number: 7699966
    Abstract: Methods and devices for point of care determination of heparin concentration in blood are described. Cartridges including protamine ion sensitive electrodes (ISEs) and reference electrodes and systems for automatically determining heparin concentration in the cartridges are provided. Some systems add blood to a protamine bolus sufficient to bind all heparin, leaving excess protamine. The excess protamine concentration can be determined by measuring the initial slope of the electrode potential rate of change, and comparing the slope to known protamine concentration slope values In some cartridges, an oscillating pressure source moves the blood-protamine mixture back and forth across the protamine ISE. Some systems also use a second blood sample having the heparin removed or degraded to create a blank reference sample. Protamine ISEs can include polyurethane polymer, DNNS ionophore, and NPOE plasticizer.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: April 20, 2010
    Assignee: Medtronic, Inc.
    Inventors: Wei Qin, Daniel S. Cheek, Christopher Hobot, Kelvin Bonnema, Randy Meyer, Douglas Dean Nippoldt, Vitally G. Sitko, Qingshan (Sam) Ye, Narayanan Ramamurthy
  • Publication number: 20080152864
    Abstract: The invention is directed to optical sensors for measuring clinically relevant analytes, their methods of manufacture, and their various uses. In an effort to develop a dry calibration method for the optical sensors of the invention it is discovered that water content inside or in the immediate vicinity of a such a sensor can have a major impact on fluorescence intensity (i.e., a sensor's response in the dry state). Thus, one of the objectives of the invention is the elimination of the bias of sensor responses measured at different humidity environments.
    Type: Application
    Filed: December 6, 2007
    Publication date: June 26, 2008
    Inventors: Narayanan Ramamurthy, Huarui He, Chao Lin
  • Patent number: 7247488
    Abstract: A method and kit for testing a multi-channel blood-testing cartridge. In particular, blood-testing cartridges are tested with plasma samples with clotting times measured to indicate whether a batch of cartridges is suitable for testing the blood of a patient.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: July 24, 2007
    Assignee: Medtronic, Inc.
    Inventors: Jyotsna Ghai, Mark A. Thompson, Colleen Lutz, Narayanan Ramamurthy, Charlene X. Yuan
  • Publication number: 20060016701
    Abstract: Methods and devices for point of care determination of heparin concentration in blood are described. Cartridges including protamine ion sensitive electrodes (ISEs) and reference electrodes and systems for automatically determining heparin concentration in the cartridges are provided. Some systems add blood to a protamine bolus sufficient to bind all heparin, leaving excess protamine. The excess protamine concentration can be determined by measuring the initial slope of the electrode potential rate of change, and comparing the slope to known protamine concentration slope values In some cartridges, an oscillating pressure source moves the blood-protamine mixture back and forth across the protamine ISE. Some systems also use a second blood sample having the heparin removed or degraded to create a blank reference sample. Protamine ISEs can include polyurethane polymer, DNNS ionophore, and NPOE plasticizer.
    Type: Application
    Filed: May 11, 2005
    Publication date: January 26, 2006
    Inventors: Wei Qin, Daniel Cheek, Christopher Hobot, Kelvin Bonnema, Randy Meyer, Douglas Nippoldt, Vitally Sitko, Qingshan (Sam) Ye, Narayanan Ramamurthy
  • Publication number: 20050006237
    Abstract: An improved ion-sensing electrode for detecting ions or polyions is provided having an electrically conducting member sheathed or coated with a layer of insulation except at an exposed, uninsulated area, where the insulation free surface of the electrically conducting member is texturized, and a polymeric membrane coated on the insulation-free surface of the electrically conducting member, where the ion selective membrane includes an ionophore. The texturized surface improves the starting EMF stability and reproducibility of the ion-sensing electrodes, and further improves membrane adherence to the electrically conducting member.
    Type: Application
    Filed: August 6, 2004
    Publication date: January 13, 2005
    Inventors: Colin Larkin, Mark Meyerhoff, Robert Baugh, Narayanan Ramamurthy
  • Publication number: 20040224416
    Abstract: A method and kit for testing a multi-channel blood-testing cartridge. In particular, blood-testing cartridges are tested with plasma samples with clotting times measured to indicate whether a batch of cartridges is suitable for testing the blood of a patient.
    Type: Application
    Filed: May 6, 2003
    Publication date: November 11, 2004
    Inventors: Jyotsna Ghai, Mark A. Thompson, Colleen Lutz, Narayanan A. Ramamurthy, Charlene X. Yuan
  • Patent number: 6476053
    Abstract: The invention provides the use of certain succinimide compounds in the treatment of mycobacterial diseases.
    Type: Grant
    Filed: July 22, 1999
    Date of Patent: November 5, 2002
    Assignee: AstraZeneca AB
    Inventors: Meenakshi Balganesh, Kantharaj Ethirajulu, Babita Singh Ganguly, Ramachandran Janakiraman, Parvinder Kaur, Rangarao Kajipalya, Santosh Nandan, Ramanujulu Pondi Murugappan, Narayanan Ramamurthy, Balasubramanian Venkataraman