Method for reading machine-readable marks on racks and receptacles

1. A sample instrument comprising:

a support configured to move from a first position to a second position, the support defining: (i) a first pocket configured to receive a first object having a first machine-readable mark and (ii) a second pocket configured to receive a second object having a second machine-readable mark, the support comprising:

a first pair of fiducial machine-readable marks containing information that identifies locations of the first pair of fiducial machine-readable marks,

a second pair of fiducial machine-readable marks containing information that identifies locations of the second pair fiducial machine-readable marks,

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

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

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

a first image as the support moves from the first position to the second position, including the first pair of fiducial machine-readable marks 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 support moves from the first position to the second position, including the second pair of fiducial machine-readable marks 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:

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 at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks 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 at least one fiducial machine-readable mark of the second pair of fiducial machine-readable marks in the second image.

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

decode the at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks and the first machine-readable mark or 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 support, wherein the first location has a predetermined association with the at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks.

3. The sample instrument of claim 2 , wherein the processor is configured to:

decode the at least one fiducial machine-readable mark of the second pair of fiducial machine-readable marks and the second machine-readable mark or 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 support, wherein the second location has a predetermined association with the at least one fiducial machine-readable mark of the second pair of fiducial machine-readable marks.

4. The sample instrument of claim 1 , wherein: the first pair of fiducial machine-readable marks includes:

a first fiducial machine-readable mark positioned on an outer surface of a first dividing wall of the support, the first dividing wall being positioned adjacent the first pocket, and

a second fiducial machine-readable mark positioned on an outer surface of a second dividing wall of the support, the second dividing wall being positioned adjacent each of the first and second pockets, the second fiducial machine-readable mark positioned on the outer surface of the second dividing wall, and

the second pair of fiducial machine-readable marks includes:

the second fiducial machine-readable mark positioned on the outer surface of the second dividing wall of the support, and

a third fiducial machine-readable mark positioned on an outer surface of a third dividing wall of the support, the third dividing wall being positioned adjacent the second pocket,

wherein the first and second dividing walls define a first gap exposing the first pocket such that the first machine-readable mark or the first empty-pocket identifying machine-readable mark is visible to the image capture device, and

wherein the second and third dividing walls define a second gap exposing the second pocket such that the second machine-readable mark or the second empty-pocket identifying machine-readable mark is visible to the image capture device.

5. The sample instrument of claim 1 , wherein the first pair of fiducial machine-readable marks includes:

a first fiducial machine-readable mark positioned on an outer surface of a first dividing wall of the support, the first dividing wall being positioned adjacent the first pocket, and

a second fiducial machine-readable mark positioned below the first fiducial machine-readable mark on the outer surface of the first dividing wall,

wherein the second pair of fiducial machine-readable marks includes:

a third fiducial machine-readable-mark positioned on an outer surface of a second dividing wall of the support, the second dividing wall being positioned adjacent each of the first and second pockets, and

a fourth fiducial machine-readable-mark positioned below the third fiducial machine-readable mark on the outer surface of the second dividing wall,

wherein the first and second dividing walls define a gap exposing the first pocket such that the first machine-readable mark or the first empty-pocket identifying machine-readable mark is visible to the image capture device.

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

7. The sample instrument of claim 1 , wherein the support is a sample rack, and wherein the first and second objects are first and second sample receptacles respectively.

8. The sample instrument of claim 1 , wherein the support is a reagent drawer, and wherein the first and second objects are first and second reagent containers, respectively.

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

10. 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 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 at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks 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 at least one fiducial machine-readable mark of the second pair of fiducial machine-readable marks in the second image.

11. 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 positions of both fiducial machine-readable marks of the first pair of fiducial machine-readable marks in the first image.

12. The sample instrument of claim 11 , wherein the processor is further configured to:

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 positions of both fiducial machine-readable marks of the second pair of fiducial machine-readable marks in the second image.

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

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

determining whether at least one fiducial machine-readable mark of a first pair of fiducial machine-readable marks on the support is in the first image;

determining, when at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks is in the first image, whether a first machine-readable mark on an object coupled to the support or a first empty-pocket identifying machine-readable mark disposed within a first pocket defined by the support is in the first image at a predetermined position relative to the at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks; and

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 support associated with the at least one fiducial machine-readable mark of first pair of fiducial machine-readable marks.

14. The method of claim 13 , further comprising:

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

determining whether at least one fiducial machine-readable mark of a second pair of fiducial machine-readable marks on the support is in the second image;

determining, when the at least one fiducial machine-readable mark of the second pair of fiducial machine-readable marks is in the second image, whether a second machine-readable mark on a second object coupled to the support or a second empty-pocket identifying machine-readable mark disposed within a second pocket defined by the support is in the second image at a predetermined position relative to the at least one fiducial machine-readable mark of the second pair of fiducial machine-readable marks; 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 support associated with the at least one fiducial machine-readable mark of the second pair of fiducial machine-readable marks.

15. The method of claim 13 , wherein the step of determining whether at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks on the support is in the first image comprises processing either the entire first image or only a portion of the first image, and

wherein the step of determining whether the first machine-readable mark on the object coupled to the support 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 at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks comprises processing either the entire first image or only a portion of the first image that includes the predetermined position.

16. The method of claim 13 , further comprising decoding at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks present in the first image.

17. The method of claim 16 , wherein one or both of the first location on the support associated with the at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks and the predetermined position relative to the at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks is determined based on decoded information from at least one fiducial machine-readable mark of the first pair of fiducial machine-readable marks present in the first image.