Integrated sample acquisition and analyte measurement method
A region of skin, other than the fingertips, is stimulated. After stimulation, an opening is created in the skin (e.g., by lancing the skin) to cause a flow of body fluid from the region. At least a portion of this body fluid is transported to a testing device where the concentration of analyte (e.g., glucose) in the body fluid is then determined. It is found that the stimulation of the skin provides results that are generally closer to the results of measurements from the fingertips, the traditional site for obtaining body fluid for analyte testing.
1. A method of electrochemically determining a concentration of an analyte in a blood sample, comprising:
manually rubbing a region of skin other than a fingertip for at least 1 second, after manually rubbing, lancing the region of skin to provide no more than 1 microliter of a blood sample on the surface of the region of skin;
contacting a sensor coupled to a meter to the blood sample to transport the blood sample to a sample chamber of the sensor, the sample chamber for holding the blood sample and comprising:
a first electrode, a second electrode, and a third electrode; and
an analyte-responsive enzyme and a redox mediator disposed in the sample chamber;
determining when the sample chamber is beginning to fill with the blood sample by detecting a signal between the first electrode and the second electrode;
determining when the sample chamber is substantially filled with the blood sample by detecting a signal between the first electrode and the third electrode; and
electrochemically determining the concentration of the analyte in the blood sample using the sensor and meter.
2. The method of claim 1 , wherein the analyte concentration is at least 10% nearer a concentration determined from blood obtained from a fingertip than a determination of the concentration of analyte from blood obtained from the region of skin without manually rubbing.
3. The method of claim 2 , wherein the concentration of blood obtained from the fingertip is in a range of 60 to 80 mg/dL.
4. The method of claim 1 , wherein no more than 0.5 microliters of the blood sample is transported to the sample chamber.
5. The method of claim 1 , wherein no more than 0.25 microliters of the blood sample is transported to the sample chamber.
6. The method of claim 1 , wherein manually rubbing the region of skin comprises manually rubbing a region of skin on a forearm.
7. The method of claim 1 , wherein manually rubbing the region of skin comprises manually rubbing a region of skin on a calf.
8. The method of claim 1 , wherein manually rubbing the region of skin comprises manually rubbing a region of skin on a thigh.
9. The method of claim 1 , wherein manually rubbing the region of skin comprises manually rubbing a region of skin on a hand.
10. The method of claim 1 , wherein manually rubbing the region of skin comprises manually rubbing a region of skin on a portion of an upper arm.
11. The method of claim 1 , wherein manually rubbing the region of skin comprises manually rubbing a region of skin on an abdomen.
12. The method of claim 1 , wherein the sensor is a side-fill electrochemical sensor.
13. The method of claim 1 , wherein the sensor is a tip-fill electrochemical sensor.
14. The method of claim 1 , wherein the first electrode, the second electrode, and the third electrode are coplanar.
15. The method of claim 1 , wherein electrochemically determining the concentration of the analyte comprises determining the concentration of the analyte using coulometry.
16. The method of claim 1 , wherein electrochemically determining the concentration of the analyte comprises determining the concentration of the analyte using amperometry.
17. The method of claim 1 , wherein electrochemically determining the concentration of the analyte comprises determining the concentration of the analyte using potentiometry.
18. The method of claim 1 , wherein the analyte is glucose.
19. The method of claim 18 , wherein the analyte-responsive enzyme is glucose oxidase or glucose dehydrogenase.
20. The method of claim 1 , wherein the analyte is a ketone.