Systems and methods for reading machine-readable marks on racks and receptacles

1. A sample instrument comprising:

a sample rack configured to move from a first position to a second position, the sample rack comprising:

a base defining a first pocket configured to receive a first object having a first machine-readable mark and a second pocket configured to receive a second object having a second machine-readable mark,

a rack cover releasably coupled to the base,

a first fiducial machine-readable mark disposed on the rack cover, the first fiducial machine-readable mark containing information that identifies a location of the first fiducial machine-readable mark,

a second fiducial machine-readable mark disposed on the rack cover, the second fiducial machine-readable mark containing information that identifies a location of the second fiducial machine-readable mark,

a first empty-pocket identifying machine-readable mark disposed within the first pocket of the base, and

a second empty-pocket identifying machine-readable mark disposed within the second pocket of the base;

an image capture device having a field of view configured to capture:

a first image including the first fiducial machine-readable mark and, (i) when the first object is received within the first pocket, the first machine-readable mark of the first object or (ii) when the first object is absent, the first empty-pocket identifying machine-readable mark, and

a second image, as the moveable support moves from the first position to the second position, including the second fiducial machine-readable mark and, (i) when the second object is received within the second pocket, the second machine-readable mark of the second object or (ii) when the second object is absent, the second empty-pocket identifying machine-readable mark; and

a processor configured to

decode the first fiducial machine-readable mark and at least one of the first machine-readable mark and the first empty-pocket identifying machine-readable mark in the first image,

associate information decoded from the first machine-readable mark or from the first empty-pocket identifying machine-readable mark with a first location on the moveable support, wherein the first location has a predetermined association with the first fiducial machine-readable mark,

decode the second fiducial machine-readable mark and at least one of the second machine-readable mark and the second empty-pocket identifying machine-readable mark in the second image, and

associate information decoded from the second machine-readable mark or from the second empty-pocket identifying machine-readable mark with a second location on the moveable support, wherein the second location has a predetermined association with the second fiducial machine-readable mark.

2. The sample instrument of claim 1 , wherein the image capture device is a camera.

3. The sample instrument of claim 1 , wherein the sample rack is configured to be moved manually.

4. The sample instrument of claim 1 , wherein the first object has different dimensions than the second object.

5. The sample instrument of claim 1 , wherein the first object is a first sample receptacle, and wherein the second object is a second sample receptacle.

6. The sample instrument of claim 1 , wherein the rack cover includes a cover identifying machine-readable mark.

7. The sample instrument of claim 6 , wherein the image capture device is configured to capture a third image including the cover identifying machine readable mark.

8. The sample instrument of claim 7 , wherein the processor is configured to decode the cover identifying machine-readable mark in the third image.

9. The sample instrument of claim 8 , wherein the processor is configured to determine a position of the rack cover relative to the base from the decoded cover identifying machine-readable mark.

10. The sample instrument of claim 8 , wherein the processor is configured to determine whether the rack cover is coupled to the base from the decoded cover identifying machine-readable mark.

11. The sample instrument of claim 1 , wherein the first fiducial machine-readable mark is a first one-dimensional or two-dimensional barcode, and wherein the second fiducial machine-readable mark is, correspondingly a second one-dimensional or two-dimensional barcode.

12. The sample instrument of claim 11 , wherein the first fiducial machine-readable mark is different from the second fiducial machine-readable mark.

13. The sample instrument of claim 1 , wherein the first fiducial machine-readable mark is above the first pocket, and wherein the second fiducial machine-readable mark is above the second pocket.

14. The sample instrument of claim 1 , wherein the processor is further configured to:

identify the first machine-readable mark or the first empty-pocket identifying machine-readable mark in the first image based on a predetermined position of the first machine-readable mark or the first empty-pocket identifying machine-readable mark in the first image relative to the position of the first fiducial machine-readable mark in the first image, and

identify the second machine-readable mark or the second empty-pocket identifying machine-readable mark in the second image based on a predetermined position of the second machine-readable mark or the second empty-pocket identifying machine-readable mark in the second image relative to the position of the second fiducial machine-readable mark in the second image.

15. The sample instrument of claim 14 , wherein the processor is further configured to:

identify the first machine-readable mark or the first empty-pocket identifying machine-readable mark in the first image by processing either the entire first image, or only a portion of the first image that includes the predetermined position of the first machine-readable mark or the first empty-pocket identifying machine-readable mark in the first image relative to the position of the first fiducial machine-readable mark in the first image, and

identify the second machine-readable mark or the second empty-pocket identifying machine-readable mark in the second image by processing either the entire second image, or only a portion of the second image that includes the predetermined position of the second machine-readable mark or the second empty-pocket identifying machine-readable mark in the second image relative to the position of the second fiducial machine-readable mark in the first image.

16. A method of reading machine-readable marks on a sample rack and objects of a sample instrument, comprising:

capturing a first image of the sample rack as the sample rack moves from a first position to a second position using an image capture device;

determining whether a first fiducial machine-readable mark on a rack cover of the sample rack is in the first image;

determining, when the first fiducial machine-readable mark is in the first image, whether a first machine-readable mark on an object coupled to a base of the sample rack or a first empty-pocket identifying machine-readable mark disposed within a first pocket defined by the base of the sample rack is in the first image at a predetermined position relative to the first fiducial machine-readable mark;

associating information decoded from the first machine-readable mark on the object or from the first empty-pocket identifying machine-readable mark with a first location on the sample rack associated with the first fiducial machine-readable mark; and

capturing a second image of the moveable support as the sample rack moves from the first position to the second position using the image capture device;

determining whether a second fiducial machine-readable mark on the rack cover of the sample rack is in the second image;

determining, when the second fiducial machine-readable mark is in the second image, whether a second machine-readable mark on a second object coupled to the base of the sample rack or a second empty-pocket identifying machine-readable mark disposed within a second pocket defined by the base of the sample rack is in the second image at a predetermined position relative to the second fiducial machine-readable mark; and

associating information decoded from the second machine-readable mark on the second object or from the second empty-pocket identifying machine-readable mark with a second location on the moveable support associated with the second fiducial machine-readable mark.

17. The method of claim 16 , wherein the step of determining whether the first fiducial machine-readable mark on the rack cover of the sample rack is in the first image comprises processing either the entire first image or only a portion of the first image.

18. The method of claim 16 , wherein the step of determining whether the first machine-readable mark on the object coupled to the base of the sample rack or the first empty-pocket identifying machine-readable mark disposed within the first pocket is in the first image at the predetermined position relative to the first fiducial machine-readable mark comprises processing either the entire first image or only a portion of the first image that includes the predetermined position.

19. The method of claim 16 , further comprising decoding the first fiducial machine-readable mark present in the first image.

20. The method of claim 19 , wherein one or both of the first location on the sample rack associated with the first fiducial machine-readable mark and the predetermined position relative to the first fiducial machine-readable mark is determined based on decoded information from the first fiducial machine-readable mark present in the first image.