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 an analyte concentration in a host, the sensor system comprising:
a first sensor element configured to measure an analyte concentration and generate a first signal;
a second sensor element configured to measure the analyte concentration and generate a second signal, the second sensor element having at least one characteristic different from the first sensor element; and
sensor electronics configured to determine an analyte concentration value based on at least one of the first signal or the second signal.
2 . The system of claim 1 , wherein the sensor electronics are configured to estimate an analyte concentration value based on at least one of the first signal or the second signal and based on an estimation of a parameter.
3 . The system of claim 2 , wherein the sensor electronics are further configured to average or integrate the first signal and the second signal.
4 . The system of claim 3 , wherein the sensor electronics are further configured to assign a first weight to the first signal and assign a second weight to the second signal, wherein a magnitude of the first weight and a magnitude of the second weight are dependent on the estimation of the parameter.
5 . The system of claim 4 , wherein the parameter is associated with the analyte concentration.
6 . The system of claim 2 , wherein the parameter is associated with a time period of a sensor session.
7 . The system of claim 2 , wherein the parameter is associated with a presence of a level of an interferent.
8 . The system of claim 2 , wherein the parameter is associated with a concentration of oxygen.
9 . The system of claim 1 , wherein the first sensor element comprises a first membrane having a first hydrophilic component and a first hydrophobic component, wherein the second sensor element comprises a second membrane having a second hydrophilic component and a second hydrophobic component, and wherein the first sensor membrane and the second sensor membrane have a different hydrophilic to hydrophobic ratio.
10 . The sensor system of claim 9 , wherein the first membrane comprises a first domain configured to reduce a flux of the analyte therethrough, wherein the second membrane comprises a second domain configured to reduce a flux of the analyte therethrough, and wherein the first domain and the second domain are different.
11 . The system of claim 1 , further comprising a potentiostat configured to apply a first bias potential to the first sensor element and to apply a second bias potential to the second sensor element, wherein the first bias potential and the second bias potential are different.
12 . The system of claim 1 , wherein the first sensor element comprises a first membrane configured to reduce a flux of interferents therethrough, wherein the second sensor element comprises a second membrane configured to reduce a flux of interferents therethrough, and wherein interferent blocking characteristics of the first membrane and the second membrane are different.
13 . The system of claim 1 , wherein the first sensor element is further configured to monitor at least one levels of an interferent.
14 . A method for processing data from a sensor system configured for continuous measurement of an analyte concentration in a host, the method comprising:
receiving a first signal, associated with an analyte concentration in a host, from a first sensor element;
receiving a second signal, associated with the analyte concentration in the host, from a second sensor element, wherein the second sensor element has at least one characteristic different from the first sensor element; and
determining, using sensor electronics, an analyte concentration value based on at least one of the first signal or the second signal.
15 . The method of claim 14 , wherein determining the analyte concentration value is further based on an estimation of a parameter.
16 . The method of claim 15 wherein determining the analyte concentration value comprises averaging or integrating the first signal and the second signal.
17 . The method of claim 16 , wherein averaging or integrating the first signal and the second signal comprises assigning a first weight to the first signal and assigning a second weight to the second signal, wherein a magnitude of the first weight and a magnitude of the second weight are dependent on the estimation of the parameter.
18 . The method of claim 17 , wherein the parameter is associated with the analyte concentration.
19 . The method of claim 15 , wherein the parameter is associated with a time period of a sensor session.
20 . The method of claim 15 , wherein the parameter is associated with a presence of a level of an interferent.
21 . The method of claim 15 , wherein the parameter is associated with a concentration of oxygen.
22 . The method of claim 14 , further comprising applying a first bias potential to the first sensor element and a second bias potential to the second sensor element, wherein the first bias potential and the second bias potential are different.
23 . A sensor system for continuous measurement of an analyte concentration in a host, the sensor system comprising:
a first sensor element configured to measure analyte concentrations over a first time period of in vivo implantation; and
a second sensor element configured to measure analyte concentrations over a second time period of in vivo implantation, wherein the first time period and the second time period are different.
24 . The sensor system of claim 23 , wherein the first time period is associated with an initial period of in vivo implantation, wherein the second time period is associated with a second time period of in vivo implantation, and wherein the second period begins after the initial period of in vivo implantation has begun.
25 . The sensor system of claim 24 , wherein the first time period and the second time period overlap partially, but not completely.
26 . The sensor system of claim 24 , wherein the first time period and the second time period do not overlap.
27 . The sensor system of claim 24 , wherein the first time period is from about day 1 post-implantation to about day 3 post-implantation, and wherein the second time period is from about day 2 post-implantation to about day 10 post-implantation.
28 . The sensor system of claim 24 , wherein the first time period is from about day 1 post-implantation to about day 21 post-implantation, and wherein the second time period is from about day 10 post-implantation to about year 1 post-implantation.
29 . The sensor system of claim 23 , wherein the sensor system is configured for implantation wholly in a tissue of a host.
30 . The sensor system of claim 23 , wherein the sensor system is configured for transcutaneous placement through a skin of a host.
31 . The sensor system of claim 23 , wherein the sensor system is configured for fluid communication with a vascular system of a host.