FIELD OF THE DISCLOSURE

The present disclosure relates generally to a method and apparatus for locating a target location on a reaction cell such as a dry slide or other porous/solid media so that the target location can be used to perform an assay, and more specifically to a method and apparatus for locating, as a target location, a read center of a fluid sample on a solid media.

BACKGROUND

One method of performing an assay is by using an image of a fluid sample that has been dispensed on a solid or porous media. A problem with this method, however, is that the image profile may not be flat, with axis-symmetric gradients radiating from the center of the location where the fluid sample was dispensed. This problem can be caused, for example, by dispensing a sample at an unintended location due to imprecisions in metering, media placement, or variable media. If the area for performing the assay is taken at a pre-determined location, there can be large variations which reduce the accuracy of the assay being performed. Another problem is that there can be imperfections in the reaction image due to optical defects (e.g., dust, coating defects, etc.) or unintended flow patterns that can degrade the assay signal.

SUMMARY

The present disclosure is directed to a method and apparatus for locating a target location in a reaction cell such as a dry slide or other solid media, and using the target location to perform an assay, for example, by obtaining an average optical intensity in a predefined area centered at the target location of the assay signal. In an example embodiment, which may be used with any other embodiment disclosed herein, a method of performing at least one assay includes obtaining at least one image of a fluid sample located on a reaction cell, creating a set of derivative data including a plurality of derivative data points based on the at least one image, determining an image gradient data point for each of the plurality of derivative data points, determining a target location of the fluid sample in the reaction cell based on the image gradient data points, and performing at least one assay using the target location of the fluid sample in the reaction cell.

In another embodiment, which may be used with any other embodiment disclosed herein, the reaction cell is a solid media, a dry slide, or a reaction cuvette.

In another embodiment, which may be used with any other embodiment disclosed herein, the target location is an approximate center of a homogeneous region of the fluid sample in the reaction cell.

In another embodiment, which may be used with any other embodiment disclosed herein, the method includes performing multiple assays using target locations from a plurality of images.

In another embodiment, which may be used with any other embodiment disclosed herein, the derivative data points are first order derivatives based on colors in the at least one image. In an embodiment, the colors in the at least one image represent light intensity.

In another embodiment, which may be used with any other embodiment disclosed herein, determining the target location of the fluid sample includes at least one of: (i) using first image gradient data points having a lower image gradient than second image gradient data points; or (ii) excluding the second image gradient data points having a higher image gradient than the first image gradient data points. In an embodiment, this means that the first order derivatives are taken across the entire image, and then all pixels with the first order derivative higher than a threshold are removed, so that the center of the remaining pixels may be used to find the target location.

In another embodiment, which may be used with any other embodiment disclosed herein, the method includes removing image defects from the at least one image.

In another embodiment, which may be used with any other embodiment disclosed herein, the at least one image is a two-dimensional image.

In another embodiment, which may be used with any other embodiment disclosed herein determining the target location of the fluid sample includes detecting or measuring an indicator reaction of indicator molecules within in the reaction cell formed from at least one reagent combining with the fluid sample.

In another embodiment, which may be used with any other embodiment disclosed herein, the method includes forming a read area around the target location, and wherein performing at least one assay includes using the read area.

In a general example embodiment, which may be used with any other embodiment disclosed herein, a method of performing at least one assay includes obtaining at least one image of a fluid sample located on a reaction cell, creating a set of derivative data including a plurality of derivative data points based on the at least one image, determining a target location of the fluid sample based on the plurality of derivative data points, forming a read area around the target location, and performing at least one assay using the read area.

In another embodiment, which may be used with any other embodiment disclosed herein, the reaction cell is a solid media, a dry slide, or a reaction cuvette.

In another embodiment, which may be used with any other embodiment disclosed herein, the read area appears approximately circular in the at least one image.

In another embodiment, which may be used with any other embodiment disclosed herein, the read area appears approximately elliptical in the at least one image.

In another embodiment, which may be used with any other embodiment disclosed herein, the method includes determining an image gradient data point for each of the plurality of derivative data points, and determining the target location of the fluid sample based on the image gradient data points.

In another embodiment, which may be used with any other embodiment disclosed herein, the method includes performing multiple assays using target locations from a plurality of images.

In another embodiment, which may be used with any other embodiment disclosed herein, the at least one image is a two-dimensional image.

In another general example embodiment, which may be used with any other embodiment disclosed herein, an apparatus for performing at least one assay includes a slide reception location configured to receive at least one reaction cell having a fluid sample located thereon, an imaging device positioned and arranged relative to the slide reception location to obtain at least one image of the fluid sample located in the reaction cell, and a control unit configured to: (i) determine a target location within the fluid sample located in the reaction cell by analyzing derivative data points derived from the at least one image; and (ii) perform at least one assay based on the target location.

In another embodiment, which may be used with any other embodiment disclosed herein, the reaction cell is a solid media, a dry slide, or a reaction cuvette.

In another embodiment, which may be used with any other embodiment disclosed herein, the solid media includes a second reaction cell.

In another embodiment, which may be used with any other embodiment disclosed herein, the target location is an approximately central location of a homogeneous region of the fluid sample.

In another embodiment, which may be used with any other embodiment disclosed herein, the control unit is configured to determine the target location by analyzing an image gradient data point for each of the plurality of derivative data points.

In another embodiment, which may be used with any other embodiment disclosed herein, the control unit is configured to determine the target location by at least one of: (i) using first image gradient data points having a lower image gradient than second image gradient data points; or (ii) excluding the second image gradient data points having a higher image gradient than the first image gradient data points. In an embodiment, this means that the first order derivatives are taken across the entire image, and then all pixels with the first order derivative higher than a threshold are removed, so that the center of the remaining pixels may be used to find the target location.

In another embodiment, which may be used with any other embodiment disclosed herein, the control unit is configured to determine the target location at an approximate geometrical center of first image gradient data points having a lower image gradient than second image gradient data points.

In another embodiment, which may be used with any other embodiment disclosed herein, the control unit is configured to perform multiple different assays using target locations from a plurality of images.

In another embodiment, which may be used with any other embodiment disclosed herein, the target location of the fluid sample in the reaction cell corresponds to a location where an indicator reaction occurs such that an indicator is developed for display as target molecules in the fluid sample react with reagents in the reaction cell.

In another embodiment, which may be used with any other embodiment disclosed herein, any of the structure and functionality disclosed in connection withFIGS. 1 to 37may be combined with any other structure and functionality disclosed in connection withFIGS. 1 to 37.

In light of the present disclosure and the above aspects, it is therefore an advantage of the present disclosure to provide an improved method and apparatus for locating a target location in a reaction cell of a dry slide, reaction cuvette, or other solid media.

The advantages discussed herein may be found in one, or some, and perhaps not all of the embodiments disclosed herein. Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures.

