Miniaturized analyte sensor
The disclosed techniques include applying, using a voltage controller, multiple voltage pulses to a working electrode of a two-electrode sensor probe, and measuring, using a current sensor, the current response to the applied multiple voltage pulses. The techniques also include analyzing, using a processor, the measured current response, and calibrating, using a processor, the current sensor on the basis of the analyzed measured current response. The techniques further include determining, using a processor, a glucose concentration value on the basis of the calibrated current sensor, and transmitting, using a transmitter, the determined glucose concentration value to a receiver.
1. A method of operating a sensor for sensing glucose concentrations, comprising:
applying, using a voltage controller, multiple voltage pulses to a working electrode of a two-electrode sensor probe;
measuring, using a current sensor, a set of current responses corresponding to the applied multiple voltage pulses, wherein the set of current responses together form a quasi-Cottrell profile that approximates a portion of a Cottrell curve;
analyzing, using a processor, the set of measured current responses;
calibrating, using the processor, the current sensor on the basis of the analyzed set of measured current responses corresponding to the applied multiple voltage pulses, wherein calibrating the current sensor comprises comparing a characteristic of the quasi-Cottrell profile determined based on the analyzed set of measured current responses to sets of predetermined Cottrell profiles;
determining, using the processor, a glucose concentration value on the basis of the calibrated current sensor based on the comparison of the analyzed set of measured current responses to the sets of predetermined Cottrell profiles; and
transmitting, using a transmitter, the determined glucose concentration value to a receiver.
2. The method of claim 1 , further comprising applying multiple voltage pulses to a counter electrode of the two-electrode sensor probe to regenerate the sensor probe.
3. The method of claim 1 , wherein the quasi-Cottrell profile has a run-in section and a steady-state section, and wherein calibrating the current sensor comprises calibrating the current sensor on the basis of an analysis of the run-in section.
4. The method of claim 3 , wherein calibrating the current sensor comprises calibrating the current sensor on the basis of a measured rate of change of current with respect to time in the run-in section.
5. The method of claim 3 , wherein analyzing the set of measured current responses comprises comparing the measured run-in section of the set of current responses with one or more run-in sections of pre-determined Cottrell profiles of the sets of predetermined Cottrell profiles.
6. The method of claim 3 , wherein determining the glucose concentration value comprises determining the glucose concentration on the basis of an instantaneous current measurement measured by the current sensor in the steady-state section.
7. The method of claim 1 , wherein applying the multiple voltage pulses comprises applying the multiple voltage pulses in periodic blocks, wherein a total application time of the periodic blocks is about one hundred seconds in every five hundred seconds.
8. The method of claim 1 , wherein the sensor probe has a size to allow the sensor probe to be implantable by a needle of size 26-gauge or below.
9. The method of claim 1 , wherein the multiple voltage pulses are separated by a constant rest time.
10. The method of claim 1 , wherein the characteristic of the quasi-Cottrell profile is indicative of sensor drift.
11. The method of claim 1 , wherein comparing the characteristic of the quasi-Cottrell profile to the sets of predetermined Cottrell profiles comprises selecting a predetermined Cottrell profile associated with a characteristic that matches the characteristic of the quasi-Cottrell profile.
12. The method of claim 11 , wherein calibrating the current sensor comprises determining a known glucose concentration associated with the matching predetermined Cottrell profile.