Compensation system and method for thermistor sensing in analyte biosensors

Abstract

To provide a procedure that addresses a risk of inaccurate glucose results a non-equilibrated meter relying solely on a thermistor-based temperature measurement causes, to provide a system that compares an estimation temperature with the measurement temperature to provide information on whether the meter is properly equilibrated, to provide a system that determines analyte concentration using the estimation temperature from a temperature estimation algorithm even if non-equilibration is detected, and to provide a system that compares the estimation temperature with the measurement temperature to provide information on whether a test sensor is damaged.SOLUTION: An analyte concentration sensor system includes: a bio-sensor interface to be connected to a test sensor including a body fluid sample; a thermistor-based temperature sensor; and a controller. The controller is configured to: generate and read a signal via the bio-sensor interface; determine both a measurement ambient temperature and an estimation ambient temperature; compare these temperatures; and select any of them based on a difference to enhance measurement accuracy.SELECTED DRAWING: Figure 1

Claims

1. An analyte concentration sensor system for measuring analytes in a user's bodily fluid sample, A biosensor interface that can be operated to connect to a test sensor holding the bodily fluid sample, A thermistor-based temperature sensor configured to measure ambient temperature, The system comprises a controller connected to the biosensor interface and the thermistor-based temperature sensor, The aforementioned controller, The input signal to the biosensor interface is generated, Read the output signal from the biosensor interface, Determine the ambient temperature measured from the thermistor-based temperature sensor. Based on the output signal and the input variables determined by multiple regression analysis, the estimated ambient temperature is determined by executing a temperature estimation algorithm. Determine the absolute value of the difference between the estimated ambient temperature and the measured ambient temperature. Based on the estimated ambient temperature, the measured ambient temperature, and the absolute value of the difference between the estimated ambient temperature and the measured ambient temperature, either the estimated ambient temperature or the measured ambient temperature is selected. An analyte concentration sensor system that can operate in this manner.

2. A method for determining the suitability of measuring ambient temperature from a thermistor temperature sensor in an analyte meter, wherein the analyte meter comprises a biosensor interface and controller that are operable to connect to a test sensor holding a body fluid sample, and the method is: To generate an input signal to the biosensor interface when the test sensor having the bodily fluid sample is connected, To determine the output signal from the aforementioned test sensor, Determining the ambient temperature measured from a thermistor-based temperature sensor. The estimated ambient temperature is determined by executing a temperature estimation algorithm based on the output signal and the input variables determined by multiple regression analysis via the controller. The absolute value of the difference between the estimated ambient temperature and the measured ambient temperature is determined via the controller, and Selecting either the estimated ambient temperature or the measured ambient temperature via the controller, based on the estimated ambient temperature, the measured ambient temperature, and the absolute value of the difference between the estimated ambient temperature and the measured ambient temperature. A method that includes this.

3. The method according to claim 2, wherein the analyte is glucose and the body fluid sample is blood.

4. The method according to claim 2, wherein the input signal is a gated current measurement pulse.

5. The method according to claim 2, wherein the measured ambient temperature is selected when the estimated ambient temperature and the measured ambient temperature are within the room temperature range.

6. The method according to claim 5, wherein the room temperature range includes a high temperature side of 25°C to 30°C and a low temperature side of 13°C to 20°C.

7. The measured ambient temperature is outside the room temperature range, the estimated ambient temperature is lower than the adjusted high temperature within the room temperature range, and higher than the adjusted low temperature within the room temperature range, and the relationship between the estimated ambient temperature and the measured ambient temperature The method according to claim 2, wherein the estimated ambient temperature is selected when the absolute value of the difference exceeds an equilibrium threshold.

8. The method according to claim 7, wherein the room temperature range includes a high temperature side of 25°C to 30°C and a low temperature side of 13°C to 20°C, the adjusted high temperature is 27°C to 34°C, the adjusted low temperature is 11°C to 18°C, and the equilibrium threshold is 3°C to 10°C.

9. The method according to claim 2, wherein an error code of the test sensor is reported when the absolute value of the difference between the estimated ambient temperature and the measured ambient temperature is greater than the maximum allowable temperature compensation value.

10. The method according to claim 2, wherein an error code of the test sensor is reported when the measured ambient temperature and the estimated ambient temperature are outside the room temperature range in opposite directions.

11. The method according to claim 2, wherein the measurement ambient temperature is within the room temperature range, and the absolute value of the difference between the estimated ambient temperature and the measurement ambient temperature is greater than a predetermined residual error limit threshold, the error code of the test sensor is reported.

12. The method according to claim 11, wherein the measured ambient temperature and the estimated ambient temperature are higher than the highest temperature in the room temperature range, and the absolute value of the difference between the estimated ambient temperature and the measured ambient temperature is greater than a predetermined extreme residual error limit threshold, and the error code of the test sensor is reported.

13. The method according to claim 11, wherein the measured ambient temperature and the estimated ambient temperature are lower than the lowest temperature in the room temperature range, and the absolute value of the difference between the measured ambient temperature and the estimated ambient temperature is greater than a predetermined extreme residual error limit threshold, and the error code of the test sensor is reported.

14. The selected estimated ambient temperature or the measured ambient temperature is provided as a temperature input to the analyte concentration determination algorithm, and The analyte concentration is determined by the analyte concentration determination algorithm. The method according to claim 2, further encompassing the present invention.

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