Analyte monitoring device and methods of use
An analyte monitor includes a sensor, a sensor control unit, and a display unit. The sensor has, for example, a substrate, a recessed channel formed in the substrate, and conductive material disposed in the recessed channel to form a working electrode. The sensor control unit typically has a housing adapted for placement on skin and is adapted to receive a portion of an electrochemical sensor. The sensor control unit also includes two or more conductive contacts disposed on the housing and configured for coupling to two or more contact pads on the sensor. A transmitter is disposed in the housing and coupled to the plurality of conductive contacts for transmitting data obtained using the sensor. The display unit has a receiver for receiving data transmitted by the transmitter of the sensor control unit and a display coupled to the receiver for displaying an indication of a level of an analyte. The analyte monitor may also be part of a drug delivery system to alter the level of the analyte based on the data obtained using the sensor.
1. A computer system, comprising:
a sensor circuit configured to receive sensor data, the sensor data comprising a data stream comprising a plurality of time spaced sensor data points from an analyte sensor; and
a processing circuit configured to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with the analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point; and
wherein the processing circuit forms calibration information based at least in part on at least one reference data point and at least one sensor data point.
2. The computer system of claim 1 , wherein the change in the characteristic is based on a time period since the analyte sensor was implanted.
3. The computer system of claim 1 , wherein the processing circuit is further configured to compare the received sensor data with expected measurements that correspond to physiologically relevant analyte levels, and to determine if calibration is appropriate based on the comparison of the received sensor data with the expected measurements that correspond to physiologically relevant analyte levels.
4. The computer system of claim 3 , wherein the processing circuit is further configured to determine if the time spaced sensor data points in the received sensor data differ by less than a second threshold amount, and to determine if calibration is appropriate if it is determined that the time spaced sensor data points in the received sensor data differ by less than the second threshold amount.
5. The computer system of claim 1 , wherein the analyte sensor includes a plurality of electrodes comprising at least one working electrode, the working electrode including an analyte-responsive enzyme and a mediator, and at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and further wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.
6. The computer system of claim 1 , wherein the processing circuit is further configured to predict one or more analyte values at one or more future points in time.
7. A computer system, comprising:
a sensor circuit configured to receive sensor data, the sensor data comprising a data stream comprising a plurality of time spaced sensor data points from an analyte sensor; and
a processing circuit configured to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with the analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point; and
wherein the processing circuit creates a calibrated data point based at least in part on at least one sensor data point.
8. The computer system of claim 7 , wherein the change in the characteristic is based on a time period since the analyte sensor was implanted.
9. The computer system of claim 7 , wherein the processing circuit is further configured to compare the received sensor data with expected measurements that correspond to physiologically relevant analyte levels, and to determine if calibration is appropriate based on the comparison of the received sensor data with the expected measurements that correspond to physiologically relevant analyte levels.
10. The computer system of claim 9 , wherein the processing circuit is further configured to determine if the time spaced sensor data points in the received sensor data differ by less than a second threshold amount, and to determine if calibration is appropriate if it is determined that the time spaced sensor data points in the received sensor data differ by less than the second threshold amount.
11. The computer system of claim 7 , wherein the analyte sensor includes a plurality of electrodes comprising at least one working electrode, the working electrode including an analyte-responsive enzyme and a mediator, and at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and further wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.
12. The computer system of claim 7 , wherein the processing circuit is further configured to predict one or more analyte values at one or more future points in time.
13. A computer system, comprising:
a sensor circuit configured to receive sensor data, the sensor data comprising a data stream comprising a plurality of time spaced sensor data points from an analyte sensor; and
a processing circuit configured to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with the analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point; and
wherein the processing circuit converts at least one sensor data point into a calibrated data point.
14. The computer system of claim 13 , wherein the change in the characteristic is based on a time period since the analyte sensor was implanted.
15. The computer system of claim 13 , wherein the processing circuit is further configured to compare the received sensor data with expected measurements that correspond to physiologically relevant analyte levels, and to determine if calibration is appropriate based on the comparison of the received sensor data with the expected measurements that correspond to physiologically relevant analyte levels.
16. The computer system of claim 15 , wherein the processing circuit is further configured to determine if the time spaced sensor data points in the received sensor data differ by less than a second threshold amount, and to determine if calibration is appropriate if it is determined that the time spaced sensor data points in the received sensor data differ by less than the second threshold amount.
17. The computer system of claim 13 , wherein the analyte sensor includes a plurality of electrodes comprising at least one working electrode, the working electrode including an analyte-responsive enzyme and a mediator, and at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and further wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.
18. A computer system, comprising:
a sensor circuit configured to receive sensor data, the sensor data comprising a data stream comprising a plurality of time spaced sensor data points from an analyte sensor; and
a processing circuit configured to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with the analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point;
wherein the processing circuit forms calibration data based at least in part on at least one calibration point, the calibration point comprising a reference data point and a sensor data point; and
wherein the processing circuit is configured to evaluate the calibration point.
19. The computer system of claim 18 , wherein the change in the characteristic is based on a time period since the analyte sensor was implanted.
20. The computer system of claim 18 , wherein the processing circuit is further configured to compare the received sensor data with expected measurements that correspond to physiologically relevant analyte levels, and to determine if calibration is appropriate based on the comparison of the received sensor data with the expected measurements that correspond to physiologically relevant analyte levels.
21. The computer system of claim 20 , wherein the processing circuit is further configured to determine if the time spaced sensor data points in the received sensor data differ by less than a second threshold amount, and to determine if calibration is appropriate if it is determined that the time spaced sensor data points in the received sensor data differ by less than the second threshold amount.
22. The computer system of claim 18 , wherein the analyte sensor includes a plurality of electrodes comprising at least one working electrode, the working electrode including an analyte-responsive enzyme and a mediator, and at least one of the analyte-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and further wherein at least one of the analyte-responsive enzyme and the mediator is crosslinked with the polymer.
23. A device, comprising:
a processing circuit configured to receive sensor data, to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with an analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point; and
wherein the processing circuit forms calibration information based at least in part on at least one reference data point and at least one sensor data point.
24. A method, comprising:
receiving, at a processing circuit, sensor data comprising a data stream that includes a plurality of time spaced sensor data points from an analyte sensor;
determining, using the processing circuit, a rate of change of an analyte level based on the received sensor data;
determining, using the processing circuit, if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with the analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
receiving, at the processing circuit, reference data from an analyte reference source, the reference data comprising at least one reference data point; and
forming, using the processing circuit, calibration information based at least in part on at least one reference data point and at least one sensor data point.
25. A device, comprising:
a processing circuit configured to receive sensor data, to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with an analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point; and
wherein the processing circuit creates a calibrated data point based at least in part on at least one sensor data point.
26. A method, comprising:
receiving, at a processing circuit, sensor data comprising a data stream that includes a plurality of time spaced sensor data points from an analyte sensor;
determining, using the processing circuit, a rate of change of an analyte level based on the received sensor data;
determining, using the processing circuit, if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with the analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
receiving, at the processing circuit, reference data from an analyte reference source, the reference data comprising at least one reference data point; and
creating, using the processing circuit, a calibrated data point based at least in part on at least one sensor data point.
27. A device, comprising:
a processing circuit configured to receive sensor data, to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with an analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point; and
wherein the processing circuit converts at least one sensor data point into a calibrated data point.
28. A method, comprising:
receiving, at a processing circuit, sensor data comprising a data stream that includes a plurality of time spaced sensor data points from an analyte sensor;
determining, using the processing circuit, a rate of change of an analyte level based on the received sensor data;
determining, using the processing circuit, if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with the analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
receiving, at the processing circuit, reference data from an analyte reference source, the reference data comprising at least one reference data point; and
converting, using the processing circuit, at least one sensor data point into a calibrated data point.
29. A device, comprising:
a processing circuit configured to receive sensor data, to determine a rate of change of an analyte level based on the received sensor data, and to determine if calibration is appropriate based at least in part by evaluating a change in a characteristic associated with an analyte sensor and determining if the rate of change of the analyte level is less than a threshold amount;
wherein the processing circuit receives reference data from an analyte reference source, the reference data comprising at least one reference data point;
wherein the processing circuit forms calibration data based at least in part on at least one calibration point, the calibration point comprising a reference data point and a sensor data point; and
wherein the processing circuit is configured to evaluate the calibration point.