Lifescan Corporation

Timothy J Ohara

Mahyar Zardoshti Kermani

Maria Teodorczyk

Robert Justice Shartle

Ronald Christopher Chatelier

Alastair McIndoe Hodges

Paul G Hayter

Manoj Sharma

Darwin R Poulos

Remy Dato

Maria Aquino

Monoj K Sharma

A flexible diagnostic device has a measurement cell that is sandwiched between the conductive surfaces of two conductive-coated insulating layers. At least one of the conductive surfaces is scored with an insulating pattern, so that the flow of a conductive fluid sample into the cell can be monitored.

Electrically-conductive patterns for monitoring the filling of medical devices

Mediator stabilized reagent compositions and methods for their use in electrochemical analyte determination assays are provided. The subject reagent compositions include an enzyme, a redox mediator and a mediator-stabilizing buffer. Optionally, the reagent compositions may further include one or more of a wetting agent, detergent, enzyme cofactor and combinations thereof. Also provided are electrochemical test strips that include the subject reagent compositions, systems and kits that include the same as well as methods for using the same in analyte detection assays. The subject invention finds use in a variety of different applications, including glucose concentration determination applications.

Mediator stabilized reagent compositions and methods for their use in electrochemical analyte detection assays

Methods and devices for determining the concentration of an analyte in a physiological sample are provided which correct for errors in the analyte concentration measurement which are due to the hematocrit of the sample.

Electrochemical methods and devices for use in the determination of hematocrit corrected analyte concentrations

The present invention provides methods and systems for passively and automatically detecting the presence of a sample (the 'sample detection phase') upon application of the sample to a biosensor, identifying the sample detection time and then initiating the measurement of a targeted characteristic, e.g., the concentration of one or more analytes, of the sample (the 'measurement phase'), immediately upon sample detection. The subject methods and systems do not employ or involve the application of an electrical signal from an external source to the electrochemical cell for purposes of performing the sample detection phase and are, thus, less complicated and involve fewer steps and components.

Passive sample detection to initiate timing of an assay

A diagnostic kit for measuring a characteristic of a fluid sample includes a test strip (e.g., a disposable blood glucose test strip) and device (e.g., a hand-held meter) for measuring a property (e.g., an optical or electrochemical property) of the test strip. The device also calculates, based on the measured property of the test strip, a characteristic (e.g., blood glucose concentration or INR) of a fluid sample applied to the test strip. Stored in a memory of the device are test strip calibration codes that represent geometric regions (e.g., polygonal or hexagonal geometric regions) of a multi-dimensional calibration parameter space. The test strip calibration codes and geometric regions are distributed across the multi-dimensional calibration parameter space such that a quantization error of assigning one of test strip calibration codes to the test strip is optimally reduced. Also, a method for optimally associating test strip calibration codes to calibration parameters for use in such a diagnostic kit that includes first optimally distributing a plurality of test strip calibration codes and geometric regions represented thereby across a multi-dimensional calibration parameter space. The distribution is conducted such that a quantization error of assigning one of the test strip calibration codes to the test strip of the diagnostic kit is optimally reduced. The method also includes storing the distributed test strip calibration codes in a memory of the diagnostic kit.

Diagnostic kit with a memory storing test strip calibration codes and related methods

Methods and devices for electrochemically detecting a change in the viscosity of a fluid are provided. In the subject methods, a fluid sample is introduced into an electrochemical cell having oppositely spaced apart working and reference electrodes. An electric potential is applied to the cell to first achieve a steady state cell current. A decrease in the steady state cell current is then detected and related to a change in viscosity of the sample. In many embodiments, the sample is blood and the change in viscosity is related to the onset of coagulation in the blood sample, and often the PT of the blood sample. Also provided are test strips, kits thereof and meters for use in practicing the subject methods.

Electrochemical coagulation assay and device

Methods and devices for determining the concentration of an analyte in a physiological sample are provided. In the subject methods, the physiological sample is introduced into an electrochemical cell having a working and reference electrode. A first electric potential is applied to the cell and the resultant cell current over a period of time is measured to determine a first time-current transient. A second electric potential of opposite polarity is then applied and a second a time-current transient is determined. The preliminary concentration of the analyte is then calculated from the first and/or second time-current transient. This preliminary analyte concentration less a background value is then multiplied by a hematocrit correction factor to obtain the analyte concentration in the sample, where the hematocrit correction factor is a function of the preliminary analyte concentration and the variable &ggr; of the electrochemical cell. The subject methods and devices are suited for use in the determination of a wide variety of analytes in a wide variety of samples, and are particularly suited for the determination of analytes in whole blood or derivatives thereof, where an analyte of particular interest is glucose.

An electrochemical assay includes a method for determining with great accuracy the time at which an applied sample bridges a gap between the electrodes of an electrochemical cell. The method involves applying a constant small current across the gap, while monitoring the potential difference between the electrodes. The time at which the sample bridges the gap is marked by a sharp drop in the potential. A constant voltage is applied after the sample is detected, and the current and/or charge through the sample is monitored over a period of time. From the measured current or charge, the analyte concentration of interest can be calculated.

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San Ramon, CA, United States of America

Timothy J Ohara