Analyte sensor with impedance determination

A method of operating an analyte sensor system using sensor electronics to correct for an error from double-layer capacitance of a sensor membrane, the method comprising:

• applying a change to an analyte sensor bias voltage;
• measuring a current value for each of a plurality of time periods after application of the bias voltage change;
• determining a current at the time of the bias voltage change using the current values for the plurality of time periods;
• determining an estimated impedance using the determined current at the time of the bias voltage change;
• determining a characteristic of the analyte sensor using the estimated impedance;
• receiving from the analyte sensor a signal indicative of an analyte concentration;
• and
• determining an estimated analyte concentration level using the determined characteristic of the analyte sensor and the received signal.

An analyte sensor system comprising:

• an analyte sensor sized and shaped for insertion into a host and configured to generate a sensor signal indicative of an analyte concentration level;
• and
• sensor electronics coupled to the analyte sensor to:
• apply a change to an analyte sensor bias voltage;
• measure a current value for each of a plurality of time periods after application of the bias voltage change;
• extrapolate to determine a current at the time of the bias voltage change using the current values for the plurality of time periods;
• determine an estimated impedance using the determined current at the time of the bias voltage change;
• determine a characteristic of the analyte sensor using the estimated impedance;
• receive from the analyte sensor a signal indicative of an analyte concentration;
• and
• determine an estimated analyte concentration level using the determined characteristic of the analyte sensor and the received signal.

A method of operating an analyte sensor system using sensor electronics, comprising:

• applying a change to an analyte sensor bias voltage;
• measuring a current for one or more time periods after application of the bias voltage change;
• determining an estimated impedance based on the current and a double-layer capacitance value;
• determining a characteristic of the analyte sensor using the estimated impedance;
• receiving from the analyte sensor a signal indicative of an analyte concentration;
• and
• determining an estimated analyte concentration level using the determined characteristic of the analyte sensor and the received signal.

An analyte sensor system comprising:

• an analyte sensor sized and shaped for insertion into a host and configured to generate a sensor signal indicative of an analyte concentration level;
• and
• sensor electronics coupled to the analyte sensor, the sensor electronics to:
• apply a change to an analyte sensor bias voltage;
• measure a current for one or more time periods after application of the bias voltage change;
• determine an estimated impedance based on the current and a double-layer capacitance value;
• determine a characteristic of the analyte sensor using the estimated impedance;
• receive from the analyte sensor a signal indicative of an analyte concentration;
• and
• determine an estimated analyte concentration level using the determined characteristic of the analyte sensor and the received signal.