Use of Electrochemical Impedance Spectroscopy (EIS) in gross failure analysis
AssigneeMedtronic MiniMed, Inc.
InventorsAndrea Varsavsky, Fei Yu, Ning Yang
Life of this patent
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Abstract
Electrochemical Impedance Spectroscopy (EIS) is used in conjunction with continuous glucose monitors and continuous glucose monitoring (CGM) to enable in-vivo sensor calibration, gross (sensor) failure analysis, and intelligent sensor diagnostics and fault detection. An equivalent circuit model is defined, and circuit elements are used to characterize sensor behavior.
Claims19
A method of performing diagnostics on a subcutaneous or implanted glucose sensor having at least one working electrode, comprising:
- defining a vector containing values associated with one or more electrochemical impedance spectroscopy (EIS)-based parameters and values associated with one or more non-EIS-based parameters;
- defining a combined threshold value for a combination of said EIS-based parameters and said non-EIS-based parameters;
- performing, by a microprocessor, a first EIS procedure to generate a first set of data for said values associated with the one or more EIS-based parameters;
- after a calculated time interval, performing, by said microprocessor, a second EIS procedure to generate a second set of data for said values associated with the one or more EIS-based parameters;
- updating, by said microprocessor, the vector with said first and second sets of data;
- and
- monitoring, by said microprocessor, vector values to determine whether the sensor has lost sensitivity based on a combined vector value of said combination of EIS-based and non-EIS-based parameters crossing said combined threshold value,
- wherein sensor glucose values are blinded to a user of the sensor by the microprocessor based on the determination that the sensor has lost sensitivity.
A method of performing diagnostics on a subcutaneous or implanted glucose sensor having at least one working electrode, comprising:
- defining a vector containing values associated with one or more electrochemical impedance spectroscopy (EIS)-based parameters and values associated with one or more non-EIS-based parameters;
- defining a combined threshold value for a combination of said EIS-based parameters and said non-EIS-based parameters;
- performing, by a microprocessor, a first EIS procedure to generate a first set of data for said values associated with the one or more EIS-based parameters;
- after a calculated time interval, performing, by said microprocessor, a second EIS procedure to generate a second set of data for said values associated with the one or more EIS-based parameters;
- updating, by said microprocessor, the vector with said first and second sets of data;
- monitoring, by said microprocessor, vector values to determine whether the sensor has lost sensitivity based on a combined vector value of said combination of EIS-based and non-EIS-based parameters crossing said combined threshold value;
- and
- terminating said glucose sensor by the microprocessor based on the determination that the sensor has lost sensitivity.
Dependencies are inferred from the claim text.