IP Library › Granted Patent US 8,422,740
Granted Patent B2
US 8,422,740 · App. 12/354,141 · Granted Apr 16, 2013

Methods for determining a liquid front position on a test strip

Inventor: Scott Dylewski (Sunnyvale, CA)
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Quick Facts
Patent No.
US 8,422,740
App. No.
12/354,141
Granted
Apr 16, 2013
Kind
B2
Abstract

The present disclosure relates to methods for determining a liquid front position of a liquid on a surface of an assay test strip placing a liquid on the surface of the test strip; and acquiring one or more signals from the surface of the test strip at one or more times, comparing the one or more acquired signals to a threshold, wherein the liquid front position is a position on the surface of the test strip where a signal is greater than or less than a threshold (e.g., fixed or dynamic threshold). Such methods may be used to determine the liquid front velocity of a liquid on a surface of an assay test strip and the transit time of a liquid sample to traverse the one or more positions on the surface of the assay test strip.

Claims (46)

1. A method for determining a liquid front position of a liquid on a surface of a test strip, said method comprising:

placing a liquid on the surface of the test strip;

acquiring two or more signals from the surface of the test strip at two or more times; and

comparing the two or more acquired signals to a threshold,

wherein the liquid front position is a position on the surface of the test strip where a difference between the two or more acquired signals is greater than or less than the threshold.

2. The method of claim 1 , wherein the two or more acquired signals are subtracted from a constant prior to being compared to the threshold.

3. The method of claim 1 , wherein the two or more acquired signals are divided by a constant prior to being compared to the threshold.

4. The method of claim 1 , wherein the two or more acquired signals are compared with each other prior to being compared to the threshold.

5. The method of claim 1 , wherein the two or more acquired signals are subtracted from each other prior to being compared to the threshold.

6. The method of claim 1 , wherein a first acquired signal is divided by a second acquired signal prior to being compared to the threshold.

7. The method of claim 1 , wherein the liquid front position is a position on the surface of the test strip furthest from where the liquid was placed on the test strip where the difference between the two or more acquired signals is greater than or less than a threshold.

8. The method of claim 1 , wherein the liquid front position is a position on the surface of the test strip where the difference between the two or more acquired signals is greater than or less than a threshold and the difference between the two or more acquired signals is greater than or less than all other signals acquired from the surface of the test strip.

9. The method of claim 1 , wherein the two or more signals are images.

10. The method of claim 9 , wherein the images are pictures.

11. The method of claim 1 , wherein the two or more images are acquired by an image-based detector.

12. The method of claim 1 , wherein the test strip is a lateral flow assay test strip.

13. The method of claim 1 , wherein the liquid is a test sample.

14. The method of claim 1 , wherein the liquid is placed on the surface of the test strip prior to acquisition of a first signal.

15. The method of claim 1 , wherein the liquid is placed on the surface of the test strip subsequent to acquisition of a first signal.

16. The method of claim 1 , wherein a signal acquired prior to the liquid being placed on the surface of the test strip is compared to a signal acquired after the liquid has been placed on the surface of the test strip.

17. The method of claim 1 , wherein a signal acquired after the liquid being placed on the surface of the test strip is compared to a signal acquired after the liquid has been placed on the surface of the test strip.

18. The method of claim 1 , wherein two sequential signals acquired from the surface of the test strip are compared.

19. The method of claim 1 , wherein two nonsequential signals acquired from the surface of the test strip are compared.

20. A method for determining a liquid front velocity of a liquid on a surface of a test strip, said method comprising:

placing a liquid on the surface of the test strip;

acquiring two or more signals from the surface of the test strip at two or more times;

comparing the two or more acquired signals to a threshold;

identifying a difference between the two or more acquired signals that is greater than or less than the threshold;

determining the distance between the two acquired signals; and

calculating the liquid front velocity by dividing the distance between the two acquired signals by the time between acquisition of the two signals.

21. The method of claim 20 , wherein the acquired signals are subtracted from a constant prior to being compared to the threshold.

22. The method of claim 20 , wherein the acquired signals are divided by a constant prior to being compared to the threshold.

23. The method of claim 20 , wherein two acquired signals are compared with each other prior to being compared to the threshold.

24. The method of claim 20 , wherein two acquired signals are subtracted from each other prior to being compared to the threshold.

25. The method of claim 20 , wherein a first acquired signal is divided by a second acquired signal prior to being compared to the threshold.

26. The method of claim 20 , wherein the two or more signals are images.

27. The method of claim 26 , wherein the images are pictures.

28. The method of claim 20 , wherein the images are acquired by an image-based detector.

29. The method of claim 20 , wherein the test strip is a lateral flow assay test strip.

30. The method of claim 20 , wherein the liquid is a test sample.

31. The method of claim 20 , wherein the liquid is placed on the surface of the test strip prior to acquisition of a first signal.

32. The method of claim 20 , wherein the liquid is placed on the surface of the test strip subsequent to acquisition of a first signal.

33. The method of claim 20 , wherein a signal acquired prior to the liquid being placed on the surface of the test strip is compared to a signal acquired after the liquid has been placed on the surface of the test strip.

34. The method of claim 20 , wherein a signal acquired after the liquid being placed on the surface of the test strip is compared to a signal acquired after the liquid has been placed on the surface of the test strip.

35. The method of claim 20 , wherein two sequential signals acquired from the surface of the test strip are compared.

36. The method of claim 20 , wherein two nonsequential signals acquired from the surface of the test strip are compared.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 29, 2013
From: DYLEWSKI, SCOTT
To: ALVERIX, INC.
Reel/Frame 030114/0653 →
Continuity (1)
Related Publication 20100177930A1 · Jul 15, 2010