Small volume in vitro analyte sensor and methods
First Claim
1. A 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; and
an insertion monitor disposed on the second major surface of one of the first substrate and the second substrate, the insertion monitor being configured and arranged to provide a path for electrical current between at least two contact leads of a meter for indication that the sensor has been properly inserted into the meter.
0 Assignments
0 Petitions
Accused Products
Abstract
A small volume 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. In one embodiment, the sensor determines the concentration of the analyte by discharging an amount of charge into the sample, determining the time needed to discharge the charge, and determining the current used to electrolyze a portion of the to analyte using the amount of charge and the amount of time.
-
Citations
22 Claims
-
1. A 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; and
an insertion monitor disposed on the second major surface of one of the first substrate and the second substrate, the insertion monitor being configured and arranged to provide a path for electrical current between at least two contact leads of a meter for indication that the sensor has been properly inserted into the meter. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A sensor strip 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; and
a plurality of contact pads disposed on the first and second substrates, at least one of the contact pads being in electrical communication with the working electrode and at least one other contact pad being in electrical communication with the counter electrode, wherein each contact pad has a contact pad width measured parallel to a width of the first and second substrates, and wherein the sum of the contact pad widths is greater than the width of the first substrate and greater than the width of the second substrate. - View Dependent Claims (8)
-
-
9. A connector comprising:
-
a plurality of contact structures for releasable connection to an electrochemical analyte sensor, wherein each contact lead comprises a proximal end for electrical connection to a sensor contact, and a distal end for electrical connection to an electrical device; and
wherein the plurality of contact leads comprises one or more first contact leads extending longitudinally from the distal end to the proximal end, and one or more second contact leads extending longitudinally from the distal end past the proximal end of the one or more first contact leads and angling toward a longitudinal center line of the sensor. - View Dependent Claims (10, 11, 13, 15, 16, 19, 20)
-
-
12. A method for the manufacture of a sensor comprising the steps of:
-
providing an adhesive having first and second surfaces covered with first and second release liners;
cutting through the first release liner but not through the second release liner to define a plurality of sample chamber regions;
removing a portion of the first release liner to expose a portion of the first adhesive surface leaving a remaining portion of the first release liner over the sample chamber regions;
applying the exposed first adhesive surface to a first substrate;
removing the second release liner together with the adhesive and first release liner of the sample chamber regions to expose the second adhesive surface and to expose the first substrate in the sample chamber region; and
applying a second substrate over the second adhesive surface forming a sample chamber in the sample chamber region, wherein a plurality of conductive traces are disposed on the first substrate, the second substrate, or a combination thereof, the conductive traces defining at least one working electrode and at least one counter electrode, and the sample chambers are disposed to allow an analyte sample disposed in the sample chambers to be electrolyzed by a current flowing between the working electrode and the counter electrode; and
separating a plurality of electrochemical sensors, each electrochemical sensor comprising at least one of the working electrodes, at least one of the counter electrodes, and at least one of the sample chambers.
-
-
14. A method for determining a concentration of an analyte in a body fluid sample, the method comprising steps of:
-
disposing a body fluid sample in a sample chamber of an electrochemical sensor, the electrochemical sensor further comprising at least one working electrode and at least one counter electrode for electrolyzing an analyte in the body fluid sample in the sample chamber of the electrochemical sensor;
electrolyzing at least a portion of an analyte in the body fluid sample by causing a current to flow between the at least one working electrode and the at least one counter electrode;
determining, during the electrolyzing of the analyte, a plurality of current values, at least some of the current values being obtained while the electrolysis of the analyte in the sensor is substantially diffusion limited;
determining, from the current values obtained while the electrolysis of the analyte in the sensor is substantially diffusion limited, parameters for extrapolation of a relationship between the current values and time;
determining from the plurality of current values the amount of an actual charge consumed in the partial electrolysis of the analyte in the sample;
determining, from the parameters for extrapolation of the relationship between the current values and time, an extrapolated charge required to electrolyze the analyte remaining in the sample;
determining the concentration of the analyte in the body fluid sample from the actual charge and the extrapolated charge.
-
-
17. An e lectrochemical sensor device comp ri ing:
-
(a) a n electrochemical sensor compris ing (i) at least one working electrode, (ii) at least one counter electrode, and (iii) a sample ch a mber for holding a body fluid sample in electrolytic contact with the at least one working electrode and at least one counter electrode; and
(b) a processor coupled to the electrochemical sensor, the processor being configured and arranged to (i) electrolyze at least a portion of an analyte in the body fluid sample by causing a current to flow between the at least one working electrode and at least one counter electrode;
(ii) determine, during the electrolyzing of the analyte, a plurality of current values, at least some of the current values being obtained while the electrolysis of the analyte in the sensor is substantially diffusion limited;
(iii) determine, from the current values obtained while the electrolysis of the analyte in the sensor is substantially diffusion limited, parameters for extrapolation of a relationship between the current values and time;
(iv) determine the amount of an actual charge consumed in the partial electrolysis of the analyte in the sample;
(v) determine an extrapolated charge required to electrolyze the analyte remaining in the sample; and
(vi) determine, from the actual charge and the extrapolated charge, the concentration of the analyte in the body fluid sample.
-
-
18. A method of determining an amount of current used to electrolyze a portion of an analyte in a body fluid sample disposed in an electrochemical sensor, the method comprising:
-
discharging an amount of charge into the body fluid sample disposed in the electrochemical sensor and electrolyzing the analyte;
determining an amount of time needed to discharge the amount of charge; and
determining the current used to electrolyze the portion of the analyte using the amount of charge and the amount of time.
-
-
21. A n electrochemical sensor device, comprising:
-
(a) an electrochemical sensor comprising (i) at least one working electrode, (ii) at least one counter electrode, and (iii) a sample chamber for holding a body fluid sample in electrolytic contact with the at least one working electrode and at least one counter electrode; and
(b) a measuring device comprising (i) a capacitor configured and arranged for coupling to the at least one working electrode to repeatedly deliver an amount of charge by repeatedly discharging, for electrolyzing at least a portion of an analyte in a body fluid disposed in the sample chamber, (ii) a clock to measure discharge times of the capacitor, and (iii) a processor to determine a concentration of the analyte in the body fluid based on the discharge times.
-
-
22. A sensor comprising:
-
a first substrate having a first major surface and a second major surface opposing the first major surface;
a second substrate havinga 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; and
a conductive trace positioned on the second major surface of one of the first substrate and the second substrate, the conductive trace electrically connected to two or more contact pads for electrical contact with a connector, the conductive trace configured and arranged to close an electrical circuit, and wherein conductive trace has a resistance that carries information related to the sensor.
-
Specification