Analyte sensor
Devices and methods are provided for continuous measurement of an analyte concentration. The device can include a sensor having a plurality of sensor elements, each having at least one characteristic that is different from other sensor(s) of the device. In some embodiments, the plurality of sensor elements are each tuned to measure a different range of analyte concentration, thereby providing the device with the capability of achieving a substantially consistent level of measurement accuracy across a physiologically relevant range. In other embodiments, the device includes a plurality of sensor elements each tuned to measure during different time periods after insertion or implantation, thereby providing the sensor with the capability to continuously and accurately measure analyte concentrations across a wide range of time periods. For example, a sensor system 180 is provided having a first working electrode 150 comprising a first sensor element 102 and a second working electrode 160 comprising a second sensor element 104 , and a reference electrode 108 for providing a reference value for measuring the working electrode potential of the sensor elements 102, 104.
1. A sensor system for continuous measurement of a glucose concentration in a host, the sensor system comprising:
a first sensor configured to be implanted in a host and configured to continuously measure a glucose concentration and generate a first signal, wherein the first sensor is associated with a first sensor accuracy during a first time period of a sensor session;
a second sensor configured to be implanted in the host and configured to continuously measure a glucose concentration and generate a second signal, wherein the second sensor is associated with a second sensor accuracy during the first time period of the sensor session; and
sensor electronics configured to determine a glucose concentration value based on at least one of the first or the second signal, wherein the sensor electronics are configured to integrate the first signal and the second signal by providing a distribution of weights associated with the first signal and the second signal and by according a first weight to the first signal and according a second weight to the second signal, wherein the distribution of weights among the first and second sensors is a function of time associated with the initiation of the sensor session.
2. The sensor system of claim 1 , wherein the first sensor and the second sensor are both configured to generate a signal during a second time period, wherein the first time period corresponds to an initial period of in vivo implantation, wherein the second time period corresponds to a second time period of in vivo implantation, and wherein the second period begins after the initial period of in vivo implantation has begun.
3. The sensor system of claim 2 , wherein the first time period and the second time period overlap partially, but not completely.
4. The sensor system of claim 2 , wherein the first time period and the second time period do not overlap.
5. The sensor system of claim 2 , wherein the first time period begins before less than 3 hours post-implantation, and wherein the second time period begins after more than 3 hours post-implantation.
6. The sensor system of claim 2 , wherein the first time period begins before less than 6 hours post-implantation, and wherein the second time period begins after more than 6 hours post-implantation.
7. The sensor system of claim 1 , wherein at least one of the first sensor or the second sensor is configured for transcutaneous placement through a skin of a host.
8. The sensor system of claim 1 , wherein the sensor system is configured for fluid communication with a vascular system of a host.
9. A method for processing data from a sensor system configured for continuous measurement of a glucose concentration in a host, the method comprising:
receiving a first signal indicative a glucose concentration in a host from a first sensor;
receiving a second signal indicative of a glucose concentration in the host from a second sensor; and
determining during a sensor session, using sensor electronics, a glucose concentration value based on at least one of the first signal or the second signal, wherein determining the glucose concentration value comprises integrating the first signal and the second signal, wherein integrating the first signal and the second signal comprises according a first weight to the first signal and according a second weight to the second signal, and wherein a magnitude of the first weight and a magnitude of the second weight are a function of time associated with an initiation of the sensor session.
10. The method of claim 9 , wherein the sensor session comprises a first time period and a second time period.
11. The method of claim 10 , wherein the first time period corresponds to an initial period of in vivo implantation, wherein the second time period corresponds to a second time period of in vivo implantation, and wherein the second period begins after the initial period of in vivo implantation has begun.
12. The method of claim 10 , wherein the first time period and the second time period overlap partially, but not completely.
13. The method of claim 10 , wherein the first time period and the second time period do not overlap.
14. The method of claim 10 , wherein the first time period begins before less than 3 hours post-implantation, and wherein the second time period begins after more than 3 hours post-implantation.
15. The method of claim 10 , wherein the first time period begins before less than 6 hours post-implantation, and wherein the second time period begins after more than 6 hours post-implantation.
16. The method of claim 9 , wherein at least one of the first sensor or the second sensor is configured for transcutaneous placement through a skin of a host.