Test Sensor with Under-Fill Protection

• US 20100009455A1
• Filed: 05/03/2007
• Published: 01/14/2010
• Est. Priority Date: 05/08/2006
• Status: Abandoned Application

• Current Assignee: Bayer Healthcare LLC (Bayer AG)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Dosmann, Andrew J., Diehl, Jason R.
• Application Number:
  US12/226,968
• Publication Number:
  US 20100009455A1
• Time in Patent Office: Days
• US Class Current: 436/164
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150213 Venting means
• CPC Class Codes: A61B 5/150358 Strips for collecting blood, e.g. absorbent optical reagent test strips G01N21/8483; chemical reagent test strips G01N33/4875, G01N33/52
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/0621 Control of the sequence of chambers filled or emptied
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/0838 Capillaries
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

A test sensor for testing an analyte concentration in a fluid sample includes a pre-fill capillary, formed by a base and a lid of the test sensor, and a sensing capillary. The pre-fill capillary is in fluid communication with the sensing capillary. The pre-fill capillary is first filled with the fluid sample and a portion of the fluid sample then moves by capillary action to the sensing capillary for testing of the analyte concentration.

Claims

1. A test sensor for measuring the concentration of an analyte in a fluid sample, the test sensor comprising:

a base and a lid;

a pre-fill capillary formed by the connection of the base and the lid, the pre-fill capillary adapted to receive the fluid sample from a test subject; and

a sensing capillary located between the base and the lid, the sensing capillary being in fluid communication with the pre-fill capillary and adapted for drawing at least a portion of the fluid sample from the pre-fill capillary for testing by an analyte-testing instrument.

2. The test sensor of claim 1, wherein the combined volume of the pre-fill capillary and the sensing capillary is less than about 450 nanoliters.

3. The test sensor of claim 2, wherein the combined volume of the pre-fill capillary and the sensing capillary is in the range of about 150 nanoliters to less than about 450 nanoliters.

4. The test sensor of claim 1, wherein the volume of the pre-fill capillary is greater than the volume of the sensing capillary.

5. The test sensor of claim 4, wherein the volume of the pre-fill capillary is at least two times greater than the volume of the sensing capillary.

6. The test sensor of claim 1, wherein the sensing capillary is adapted to be filled with the fluid sample from the pre-fill capillary by capillary action.

7. The test sensor of claim 6, wherein the pre-fill capillary is filled with the fluid sample before the sensing capillary begins to fill.

8. The test sensor of claim 1, wherein the connection of the base and the lid occurs via an adhesive.

9. The test sensor of claim 1, wherein the test sensor further comprises a spacer located between the base and the lid.

10. The test sensor of claim 1, wherein the test sensor further comprises an alignment aperture adapted for guiding the sensing capillary into an alignment channel of the analyte-testing instrument.

11. The test sensor of claim 10, wherein the width of the alignment channel is greater than the outside width of the sensing capillary.

12. The test sensor of claim 1, wherein the test sensor further comprises a lip at a first end of the test sensor to prevent the pre-fill capillary from being plugged while receiving the fluid sample.

13. The test sensor of claim 1, wherein the test sensor further comprises a vent at a second end of the test sensor for venting the sensing capillary.

14. A method of determining a concentration of an analyte in a fluid sample with a test sensor, the method comprising the acts of:

providing the test sensor having a pre-fill capillary and sensing capillary, the pre-fill capillary adapted to receive the fluid sample from a test subject;

collecting the fluid sample from the test subject via the pre-fill capillary;

moving a portion of the fluid sample from the pre-fill capillary into the sensing capillary, the sensing capillary being in fluid communication with the pre-fill capillary; and

measuring the concentration of the analyte in the fluid sample.

15. The method of claim 14, wherein the act of collecting the fluid sample includes allowing the test subject to fill the pre-fill capillary at different times.

16. The method of claim 14, wherein the act of measuring the concentration of the analyte occurs by light transmission through the sensing capillary.

17. The method of claim 14, wherein the combined volume of the pre-fill capillary and the sensing capillary is less than about 450 nanoliters.

18. The method of claim 17, wherein the combined volume of the pre-fill capillary and the sensing capillary is in the range of about 150 nanoliters to less than about 450 nanoliters.

19. The method of claim 14, wherein the volume of the pre-fill capillary is greater than the volume of the sensing capillary.

20. The method of claim 19, wherein the volume of the pre-fill capillary is at least two times greater than the volume of the sensing capillary.

21. The method of claim 14, further comprising guiding the test sensor into an alignment channel of an analyte-testing instrument via an alignment aperture in the test sensor.

22. The method of claim 14, wherein the act of collecting the fluid sample via the pre-fill capillary comprises providing a lip at a first end of the test sensor to prevent the pre-fill capillary from being plugged while receiving the fluid sample.

23. A test sensor for measuring the concentration of an analyte in a fluid sample, the test sensor comprising:

a base and a lid; and

a sensing capillary located between the base and the lid, the sensing capillary having a volume that is less than about 150 nanoliters.

24. The test sensor of claim 23, wherein the sensing capillary is made from synthetic fused quartz.

25. The test sensor of claim 23, wherein the sensing capillary includes a coat of transparent polyimide on the outside surface of the sensing capillary to prevent breakage.