Rapid diagnostic test systems and methods

1. A rapid diagnostic test system comprising:

a lateral-flow strip for performing a binding assay, the lateral-flow strip comprising a binding agent with a deposition density that varies periodically along at least a portion of the lateral-flow strip; and

an imaging system operative to capture an image of the portion of the lateral-flow strip, wherein the imaging system comprises a lens configured to collect light from the portion of the lateral-flow strip and generate by free-space propagation, a Fourier transformed image of at least a portion of the lateral-flow strip.

2. The system of claim 1 , further comprising:

an image data analyzer coupled to the imaging system, the image data analyzer operative to use a priori information of the deposition density to analyze the captured image for detecting a bound antibody having a label attached thereto.

3. The system of claim 2 , wherein the imaging system is a digital image capture system operative to generate digital image data.

4. The system of claim 1 , wherein the binding agent is a bound antibody and the deposition density varies periodically in one of a sinusoidal pattern and a binary pattern and wherein the system further comprises an optical detector configured to detect the one of a sinusoidal pattern and a binary pattern from the Fourier transformed image.

5. The system of claim 1 , wherein the binding agent is a bound antibody and the deposition density varies periodically in one of a sinusoidal pattern and a binary pattern.

6. The system of claim 5 , further comprising:

an image data analyzer coupled to the imaging system, the image data analyzer operative to use a priori information of the one of a sinusoidal pattern and a binary pattern to analyze the captured image for detecting a bound antibody having a label attached thereto.

7. The system of claim 6 , further comprising:

a deposition system comprising a nozzle configured to direct the bound antibody towards the portion of the lateral-flow strip.

8. The system of claim 6 , further comprising:

an image data analyzer coupled to the imaging system, the image data analyzer operative to analyze the captured image comprising the one of a sinusoidal pattern and a binary pattern for detecting a bound antibody having a label attached thereto.

9. The system of claim 8 , wherein the lateral-flow strip further comprises a reference imaging pattern for enabling the image data analyzer to detect the one of the sinusoidal pattern and a binary pattern.

10. A rapid diagnostic testing method, the method comprising:

contacting a lateral-flow strip with a test sample comprising at least one target anayte;

labeling the target analyte to generate a labeled target anayte;

binding the labeled target analyte to a binding agent having a periodic variation of deposition density;

capturing an image of at least a portion of the lateral-flow strip; and

detecting the periodic variation in the captured image to identify bound labeled target analyte.

11. The method of claim 10 , wherein capturing the image comprises using a digital image capture system to generate digital image data.

12. The method of claim 11 , wherein detecting the periodic variation comprises one of a) visual detection by a human operator and b) automatic detection.

13. The method of claim 11 , wherein detecting the periodic variation comprises detecting a reference imaging pattern on the lateral-flow strip.

14. The method of claim 10 , wherein capturing the image comprises a Fourier-transformation by propagating light through a lens.

15. The method of claim 10 , wherein capturing the image comprises:

scanning the lateral-flow strip at a first scan rate;

generating a scanned output signal having a temporal frequency equal to a product of the first scan rate and a spatial frequency of the periodic variation of deposition density.

16. The method of claim 10 , wherein detecting the periodic variation comprises identifying a spatial frequency component in the captured image.

17. The method of claim 16 , further comprising using a change in a magnitude of the spatial frequency component to generate a quantitative test result.

18. A lateral-flow test strip, comprising:

a test result region comprising a binding agent having a periodic variation of deposition density, wherein the periodic variation comprises one of a sinusoidal pattern and a binary pattern; and

a test completion region comprising the binding agent.

19. The lateral-flow test strip of claim 18 , further comprising a reference periodic pattern.

20. The lateral-flow test strip of claim 18 , wherein the reference periodic pattern is located in the test completion region.