Methods for determining a wavefront position on a test strip

• US 9,165,357 B2
• Filed: 03/14/2013
• Issued: 10/20/2015
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Alverix, Inc. (Becton, Dickinson & Co)
• Original Assignee: Alverix, Inc. (Becton, Dickinson & Co)
• Inventors: Dylewski, Scott
• Primary Examiner(s): Rogers, David A
• Application Number:
  US13/804,248
• Publication Number:
  US 20130195332A1
• Time in Patent Office: 950 Days
• US Class Current: 1/1
• CPC Class Codes: G01F 1/7086 using optical detecting arrangements
• CPC Class Codes: G01N 21/78 producing a change of colour
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04
• CPC Class Codes: G06T 7/0012 Biomedical image inspection

Abstract

The present disclosure relates to methods for determining a wavefront 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 wavefront 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 wavefront 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

1. A method for determining a starting time for a test assay, 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 starting time of the assay is determined as the time at which a difference between the two or more acquired signals is greater than or less than a 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 two or more acquired signals are compared with each other prior to being compared to the threshold.

5. The method of claim 1, wherein 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 signal is an image.

8. The method of claim 7, wherein the image is a picture.

9. The method of claim 1, wherein the image is acquired by an image-based detector.

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

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