Analyte sensor with insertion monitor, and methods
A sensor, and methods of making, for determining the concentration of an analyte, such as glucose or lactate, in a biological fluid such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. The sensor includes a working electrode and a counter electrode, and can include an insertion monitoring trace to determine correct positioning of the sensor in a connector.
1 . A system for determining the concentration of an analyte in a sample, the system comprising:
an analyte sensor for determining the concentration of an analyte in a sample, the sensor comprising an indicator monitor encoding calibration code; and
a meter configured for electrical connection to the indicator monitor and to read the calibration code.
2 . The system of claim 1 , wherein the indicator monitor is a conductive strip on an exterior surface of the sensor.
3 . The system of claim 1 , wherein the calibration code is based on a resistance of the indicator monitor.
4 . The system of claim 3 , wherein the indicator monitor comprises carbon.
5 . The system of claim 4 , wherein the indicator monitor comprises carbon and silver.
6 . The system of claim 1 , wherein the calibration code is based on a pattern of conductive areas that form the indicator monitor.
7 . The system of claim 1 , wherein the sensor further comprises a sample chamber, and the calibration code relates to a volume of the sample chamber.
8 . The system of claim 7 , wherein the sample chamber volume is no more than about 1 μL.
9 . The system of claim 8 , wherein the sample chamber volume is no more than about 0.5 μL.
10 . The system of claim 9 , wherein the sample chamber volume is no more than about 0.1 μL
11 . The system of claim 1 , wherein the meter is configured to determine the concentration of analyte in the sample by coulometry.
12 . The system of claim 1 , wherein the meter is configured to determine the concentration of analyte in the sample by amperometry.
13 . The system of claim 1 , wherein the meter is configured to determine the concentration of analyte in the sample by potentiometry.
14 . A sensor for determining a concentration of analyte, the sensor comprising:
a first substrate having a first major surface and a second major surface opposing the first major surface;
a second substrate having a first major surface and a second major surface opposing the first major surface, the first and second substrates being disposed so that the first major surface of the first substrate is in facing relationship with the first major surface of the second substrate;
a working electrode disposed on the first major surface of the first substrate;
a counter electrode disposed on the first major surface of one of the first substrate and the second substrate, the working electrode and the counter electrode;
a sample chamber having the working electrode and counter electrode present therein;
an insertion monitor on one of the first and the second major surfaces of one of the first substrate and the second substrate, the insertion monitor including a conductive stripe extending across a width of the sensor strip and the insertion monitor providing encoded calibration information about the strip
15 . The sensor of claim 14 further comprising a spacer between the first substrate and the second substrate, the spacer material, the first substrate and the second substrate defining the sample chamber.
16 . The sensor of claim 15 wherein the sample chamber has a volume of no more than about 1 μL.
17 . The sensor of claim 16 wherein the sample chamber has a volume of no more than about 0.5 μL.
18 . The sensor of claim 14 , wherein the insertion monitor has two or more contact regions for electrical contact with the meter.
19 . The sensor of claim 14 , wherein the insertion monitor is configured and arranged to provide encoded calibration information about the strip.