Method and device for selecting a position for reading an image of a slide medium

Abstract

The present disclosure is directed to methods and apparatus for locating a target position on a reaction pool and performing an assay using the target position. In an example embodiment, a method for performing at least one assay includes: obtaining at least one image of a fluid sample located on a reaction pool; and creating a derivative data set including a plurality of derivative data points based on the at least one image. The method also includes: determining an image gradient data point for each of the plurality of derivative data points, and determining a target position of the fluid sample in the reaction pool based on the image gradient data point. The method further includes: performing at least one assay using the fluid sample at the target position in the reaction pool.

Description

Technical Field

[0001] The present disclosure generally relates to methods and apparatus for locating a target position on a reaction pool such as a dry slide or other porous / solid medium so that the target position can be used to perform an assay, and more specifically to methods and apparatus for locating a reading center of a fluid sample on a solid medium as a target position. Background Art

[0002] One method of carrying out the determination is by using an image of a fluid sample that has been dispensed on a solid or porous medium. However, a problem with this method is that the image profile may not be flat, with an axisymmetric gradient emanating from the center of the location where the fluid sample is dispensed. This problem may be caused, for example, by dispensing the sample at an undesirable location due to inaccuracies in metering, medium placement or variable media. If the area used to carry out the determination is taken at a predetermined location, there may be large variations, which may reduce the accuracy of the determination carried out. Another problem is the presence of imperfections in the reaction image due to optical defects (e.g., dust, coating defects, etc.) or unexpected flow patterns, which may degrade the determination signal. Summary of the invention

[0003] The present disclosure relates to methods and apparatus for locating a target position in a reaction pool, such as a dry slide or other solid medium, and performing an assay using the target position, for example, by obtaining an average optical intensity in a predefined area centered on the target position of an assay signal. In an example embodiment that can be used with any other embodiment disclosed herein, a method for performing at least one assay includes obtaining at least one image of a fluid sample located on a reaction pool, creating a derivative data set 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 position of the fluid sample in the reaction pool based on the image gradient data point, and performing at least one assay using the target position of the fluid sample in the reaction pool.

[0004] In another embodiment, which may be used with any other embodiment disclosed herein, the reaction well is a solid medium, a dry slide, or a reaction cuvette.

[0005] In another embodiment that may be used with any other embodiment disclosed herein, the target location is the approximate center of the homogenous region of the fluid sample in the reaction pool.

[0006] In another embodiment, which may be used with any other embodiment disclosed herein, the method includes using target locations from a plurality of images to perform a plurality of determinations.

[0007] In another embodiment, which may be used with any other embodiment disclosed herein, the derivative data point is based on a first derivative of a color in the at least one image. In an embodiment, the color in the at least one image represents light intensity.

[0008] In another embodiment that may be used with any other embodiment disclosed herein, determining a target location of a fluid sample includes at least one of: (i) using a first image gradient data point having a lower image gradient than a second image gradient data point; or (ii) excluding a second image gradient data point having a higher image gradient than the first image gradient data point. In an embodiment, this means taking a first order derivative across the entire image and then removing all pixels whose first order derivative is above a threshold, so that the center of the remaining pixels can be used to find the target location.

[0009] In another embodiment, which may be used with any other embodiment disclosed herein, the method includes removing image defects from at least one image.

[0010] In another embodiment that may be used with any other embodiments disclosed herein, the at least one image is a two-dimensional image.

[0011] In another embodiment that 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 an indicator molecule within a reaction well formed by a combination of at least one reagent and the fluid sample.

[0012] In another embodiment that may be used with any other embodiment disclosed herein, the method includes forming a read zone around a target location, and wherein performing at least one assay includes using the read zone.

[0013] In a general example embodiment that 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 pool, creating a derivative data set comprising 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 zone around the target location, and performing at least one assay using the read zone.

[0014] In another embodiment, which may be used with any other embodiment disclosed herein, the reaction well is a solid medium, a dry slide, or a reaction cuvette.

[0015] In another embodiment, which may be used with any other embodiment disclosed herein, the read zone appears to be approximately circular in at least one image.

[0016] In another embodiment, which may be used with any other embodiment disclosed herein, the read zone appears to be approximately elliptical in at least one image.

[0017] In another embodiment that may be used with any other embodiment disclosed herein, the method includes determining an image gradient data point for each of a plurality of derivative data points, and determining a target position of the fluid sample based on the image gradient data points.

[0018] In another embodiment that may be used with any other embodiment disclosed herein, the method includes performing a plurality of determinations using target locations from a plurality of images.

[0019] In another embodiment, which may be used with any other embodiments disclosed herein, at least one image is a two-dimensional image.

[0020] In another general exemplary embodiment that may be used with any other embodiment disclosed herein, an apparatus for performing at least one assay includes: a slide receiving position configured to receive at least one reaction pool having a fluid sample located thereon; an imaging device positioned and arranged relative to the slide receiving position to obtain at least one image of the fluid sample located in the reaction pool; and a control unit configured to: (i) determine a target position within the fluid sample located in the reaction pool by analyzing derivative data points derived from the at least one image; and (ii) perform at least one assay based on the target position.

[0021] In another embodiment, which may be used with any other embodiment disclosed herein, the reaction well is a solid medium, a dry slide, or a reaction cuvette.

[0022] In another embodiment that may be used with any other embodiment disclosed herein, the solid medium comprises a second reaction cell.

[0023] In another embodiment that may be used with any other embodiment disclosed herein, the target location is an approximate center location of a homogenous region of the fluid sample.

[0024] In another embodiment, which may be used with any other embodiment disclosed herein, the control unit is configured to determine the target position by analyzing the image gradient data point for each of the plurality of derivative data points.

[0025] In another embodiment that 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 a first image gradient data point having a lower image gradient than a second image gradient data point; or (ii) excluding a second image gradient data point having a higher image gradient than the first image gradient data point. In an embodiment, this means taking a first order derivative across the entire image and then removing all pixels whose first order derivative is above a threshold, so that the center of the remaining pixels can be used to find the target location.

[0026] In another embodiment that may be used with any other embodiment disclosed herein, the control unit is configured to determine the target position at an approximate geometric center of a first image gradient data point having a lower image gradient than a second image gradient data point.

[0027] In another embodiment, which may be used with any other embodiment disclosed herein, the control unit is configured to perform a plurality of different determinations using the target location from a plurality of images.

[0028] In another embodiment that may be used with any other embodiment disclosed herein, a target location of the fluid sample in a reaction pool corresponds to a location where an indicator reaction occurs, such that when a target molecule in the fluid sample reacts with a reagent in the reaction pool, the indicator develops for display.

[0029] In another embodiment, which may be used with any other embodiment disclosed herein, in combination with Figures 1 to 37 Any structure and function disclosed can be combined with Figures 1 to 37 Any other structures and functions disclosed herein can be combined.

[0030] In view of the present disclosure and the above aspects, therefore, an advantage of the present disclosure is to provide an improved method and apparatus for locating a target position in a reaction pool of a dry slide, reaction cuvette or other solid media.

[0031] The advantages discussed herein may be found in one or some, but not all, of the embodiments disclosed herein.Additional features and advantages are described herein and will be apparent in the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the present disclosure will now be explained in more detail, by way of example only, with reference to the accompanying drawings, in which:

[0033] Figure 1 A diagram illustrating a side view of an example embodiment of a solid medium according to the present invention;

[0034] Figure 2 Pictured Figure 1 An exploded perspective view of a solid medium;

[0035] Figure 3 The diagram shows the holding Figure 1 A diagram of an example embodiment of a solid medium assay device;

[0036] Figure 4 illustrates a diagram of an example embodiment of a sample dispensing mechanism for dispensing a fluid sample onto a solid medium according to the present disclosure;

[0037] Figure 5 The diagram shows that Figure 4 An illustration of an example embodiment of a liquid lens formed on a solid medium by a liquid sample dispensed as shown;

[0038] Figure 6 The diagram shows Figure 5 An illustration of an example embodiment of a top perspective view and a bottom view of an example embodiment of a distribution illustrated in;

[0039] Figure 7A to Figure 7C illustrates diagrams of three example patterns that may be formed by a fluid sample on a solid medium;

[0040] Figure 8 A diagram illustrating an example embodiment of a method of performing at least one determination according to the present disclosure;

[0041] Fig. 9A and 9B illustrate diagrams of an example embodiment of a method of detecting a target location in an image of a fluid sample on a solid medium according to the present disclosure;

[0042] Fig.10 illustrates diagrams of different example patterns that may be formed by a fluid sample on a solid medium;

[0043] Fig.11 The original image and the first-order spatial derivative that can be formed by a fluid sample on a solid medium are illustrated;

[0044] Fig.12 illustrates diagrams of different defects that may be formed within an image of a fluid sample on a solid medium;

[0045] Fig.13 A diagram illustrating how specks of dust on a solid medium cause spikes in the corresponding image;

[0046] Fig.14 A diagram illustrating how the method according to the present disclosure improves the accuracy of the assay;

[0047] Fig.15 A diagram illustrating how the method according to the present disclosure improves the accuracy of the assay;

[0048] Fig.16 The present invention illustrates an exemplary embodiment of the present invention. Figures 1 to 5 Schematic diagram of an embodiment of a solid medium;

[0049] Fig.17 The diagram shows a method according to an exemplary embodiment of the present disclosure. Figure 3 an illustration of an image recorded by an assay system of the present invention, the image including a sample placed on a stagnation area of ​​each slide;

[0050] Fig.18 and Fig. 20 The diagram shows a method according to an exemplary embodiment of the present disclosure. Figure 3 An image recorded by a measuring system where dust or another contaminant is included in the sample.

[0051] Fig.19 and Fig.21 The diagram shows that the determination system is based on Fig.18 and Fig. 20 an illustration of an analysis of a sample performed using an image of the sample; and

[0052] Figures 22 to 37 The diagram shows an example embodiment according to the present disclosure. Figures 1 to 21 A graph of test result data comparing the analytical performance of an example solid medium with a known solid medium. DETAILED DESCRIPTION

[0053] The present disclosure relates to methods and devices for locating a target position on a reaction pool and using the target position to perform a determination. As discussed in more detail below, the currently disclosed methods and devices are advantageous in, for example, improving calculation time, reducing sensitivity to eccentric photometry, avoiding edges / frames to minimize the impact of non-determination signals, and detecting and removing image defects (e.g., dust, coating defects, wicking, etc.) to reduce deviations or outliers. Image defects may also include foreign matter, bubbles, scratches, etc. The present disclosure describes the reaction pool as a dry slide, a reaction cuvette, or a solid medium, but those of ordinary skill in the art will appreciate that the present disclosure can be used for other types of reaction pools, for example, porous media (such as nitrocellulose), semi-porous and solid media (such as Ouchterlony plates), liquid reagent devices (such as cuvettes), circulation pools or reaction tubes, and / or solid media chips with embedded lateral flow arrays having optical measurement zones.

[0054] Figure 1 and Figure 2 An example embodiment of a reaction cell that can be used according to the present disclosure is illustrated. Figure 1 and Figure 2In the embodiment of the present invention, the reaction pool is a solid medium 10 that can be used with the determination system 20. For example, the solid medium 10 can be a single layer or multilayer thin film element on which a fluid sample can be distributed. In the illustrated embodiment, the solid medium 10 includes a plurality of layers, including a first layer 12, which can be an upper glass slide mounting layer, which is configured to provide a hole via there to the top substrate to receive the fluid sample. The first layer can also be configured to spread the fluid sample thereon. The solid medium 10 also includes a second layer 14, which can be a reagent layer, which includes a reagent configured to react with the fluid sample to perform a specific determination. The second layer 14 can also include a supporting layer to provide support or rigidity for the reagent layer. The solid medium further includes a third layer 16, which can be a filter layer that provides a low wavelength cut-off filter used for optical analysis. The third layer 16 can include a lower glass slide mounting layer, which is configured to provide a hole via there to the bottom substrate for optical analysis.

[0055] Figure 3 An example embodiment of an assay system 20 is illustrated, which is configured to locate a target location in an image of a fluid sample on a solid medium 10 and to perform one or more assays using the target location. As shown, the assay system 20 may include: a slide receiving location 22 configured to receive at least one solid medium 10; a sample dispensing mechanism 32 configured to dispense a sample fluid onto the solid medium 10; an imaging device 24 positioned and arranged relative to the solid medium receiving location 22 to obtain at least one image of the fluid sample located on the solid medium 10; a light source 26 (e.g., one or more light emitting diode lights) configured to project light onto the solid medium 10 such that the light can be modulated by the liquid sample dispensed onto the solid medium 10; and an optional optical filter 28 configured to modulate light from the light source 26 to a specific wavelength specific to the assay being performed.

[0056] In the illustrated embodiment, the slide receiving position 22 is configured to receive and hold the solid medium 10 while a fluid sample is added to the solid medium 10 and / or while the solid medium 10 is illuminated by the light source 26 and imaged by the imaging device 24. In the illustrated embodiment, the slide receiving position 22 includes: at least one bracket that creates a first opening 22a and a second opening 22b. The fluid sample can be added to the solid medium 10 at the first opening 22a of the slide receiving position 22 (e.g., through a hole in the first layer 12), while the second opening 22b of the slide receiving position 22 enables the solid medium 10 to be illuminated and imaged (e.g., through a hole in the third layer 16) after the fluid sample has reacted with the reagent. It should be further understood that the addition of the fluid sample can occur before the slide receiving position 22 receives the solid medium 10, and the illumination and imaging of the solid medium 10 can occur at the first opening 22a at the top of the slide receiving position 22, which is opposite to the second opening 22b at the bottom of the slide receiving position 22.

[0057] Figure 2 The assay system 20 may further include: a control unit 30 configured to control one or more elements of the assay system 20, determine a target location of the fluid sample on the solid medium 10, and analyze the fluid sample on the solid medium 10 according to the method(s) described herein. The control unit 30 may include a processor and a non-transitory memory storing instructions for implementing the methods described herein, wherein the processor executes the instructions to control one or more elements of the assay system 20 to implement one or more assays.

[0058] Figure 4 The diagram shows a fluid sample dispensed onto a solid medium 10 by a sample dispensing mechanism 32 according to an example embodiment of the present disclosure. In an embodiment, the fluid sample may be dispensed onto the solid medium 10 by a sample dispensing mechanism 32 manually controlled by a user before the solid medium 10 is inserted into the slide receiving position 22 of the assay system 20. The sample dispensing mechanism 32 may be, for example, a pipette or other fluid dispensing mechanism known in the art. Alternatively, the assay system 20 may include a sample dispensing mechanism 32, such as Figure 3 Here, the sample dispensing mechanism 32 can be controlled by a user or the control unit 30 to dispense the fluid sample onto (or into) the solid medium 10 before or after the solid medium 10 is inserted into the slide receiving position 22 of the assay system 20 .

[0059] Figure 4The sample dispensing mechanism 32 is illustrated dispensing a fluid sample onto the solid medium 10 from time t1 to t5. During this time, stagnation and lateral flow create a spatial gradient due to the concentration of the coating material in the solid medium 10. As illustrated, at time t1, the fluid sample is ejected from the sample dispensing mechanism 32 onto the solid medium 10 and makes initial contact with the solid medium 10. At time t2, the fluid sample continues to be ejected from the sample dispensing mechanism 32 onto the solid medium 10, which begins to form a stagnant area 44. At time t3, the fluid sample continues to be ejected from the sample dispensing mechanism 32 onto the solid medium 10 and diffuses on the solid medium 10, which increases the size of the stagnant area 44. At time t4, the sample dispensing mechanism 32 begins to stop the ejection of the fluid sample, which causes a fluid necking to occur between the sample dispensing mechanism 32 and the solid medium 10, thereby forcing the stagnant area 44 to be directly below the sample dispensing mechanism 32. At time t5, the sample dispensing mechanism 32 no longer ejects the fluid sample, leaving a stagnant area 44. In the illustrated embodiment, the stagnant area 44 corresponds to the area with the smallest change. In some embodiments, stagnant region 44 has relatively low optical density variability and / or relatively large presence of an indicator (eg, sample dye).

[0060] Figure 5 The diagram shows that due to Figure 4 The liquid lens 46 formed by the fluid sample on the solid medium 10 is caused by the stagnant area 44 created by the dispensing process. As shown in the figure, the fluid sample forms a circular liquid lens 46 above the solid medium 10. Figure 5 As shown, the circular liquid lens 46 is formed due to the axisymmetric fluid flow from the sample dispensing mechanism 32 , which results in an axisymmetric distribution of the coating material onto the solid medium 10 .

[0061] Figure 6 A top perspective view and a bottom view showing an example embodiment of the distribution of liquid lenses 46 over stagnation areas 44 are illustrated. Figure 6 The subplot of shows the light intensity in two-dimensional space (ie, x and y space) over all pixels in the image. The center of the liquid lens 46 has a lower light intensity, while the edge of the liquid lens 46 has a higher light intensity. Figure 6 Graph 70 of FIG. 72 has the same information as graph 72, but is presented in 3-dimensions, with the z-axis representing light intensity and the x- and y-axes representing pixel position. If a pixel has a higher light intensity (at the x and y coordinates), it has a larger z value in graphs 70 and 72. Light intensity is measured by a value called an "AD count" ("ADC"). Brighter pixels have larger AD count values ​​than darker pixels.

[0062] Due to differences in the measurement dynamics and the uniformity of the coating material of the solid medium 10, there are different patterns that may be formed in the images taken of the fluid sample on the solid medium 10. Figure 7C Three example patterns that can be formed are illustrated. FIG7A shows a concave pattern, Figure 7B shows a convex pattern, and Figure 7C A complex pattern is shown. Figure 7C The common features shared by all three patterns of are: a stagnant region 44 at the center and Z-axis symmetric radiation, which is disturbed by local inhomogeneities. The present disclosure uses this common feature to locate the center of a homogeneous region of a fluid sample (e.g., relatively uniform light intensity) on a solid medium as a target location for use in performing one or more assays.

[0063] Figure 8 A method 100 for performing at least one measurement by capturing an image and processing the image as disclosed herein is illustrated. In an embodiment, the control unit 30 may include a processor and a non-transitory memory storing instructions to perform the steps of the method 100. The processor executes the instructions to cause the elements of the measurement system 20 to perform Figure 8 It should be understood by those skilled in the art that the steps of Figure 8 One or more of the steps shown may be changed, and / or additional steps may be added, and / or the order of certain steps may be rearranged.

[0064] At step 102, the imaging device 24 records at least one image of the fluid sample dispensed onto the solid medium 10. For example, the image can be recorded while the light source 26 projects light onto the solid medium 10. The light from the light source 26 is configured so that the emitted light is transmitted by the target molecule in the sample, which has reacted with one or more reagents on the solid medium 10, thereby providing a visual indication of the reaction (e.g., an indicator reaction). In some examples, the optical filter 28 and / or the filter provided by the solid medium 10 are configured to modulate the light from the light source 28. The imaging device 24 can be, for example, a charge coupled device ("CCD") camera, which can, for example, record a two-dimensional image showing an approximately elliptical or circular fluid sample on the solid medium 10. In an embodiment, the wavelength required for a particular assay can be programmed into or provided to the control unit 30, which can then control the light source 26 and the optical filter 28 so that the correct wavelength of light for the assay being performed is projected onto the solid medium 10 while the image is recorded by the imaging device 24.

[0065] At step 104, the control unit 30 normalizes the image and determines a target location for the assay. Step 104 is shown and described in more detail in FIG. 9 and the corresponding description below. As explained in more detail below, step 104 may include one or more of: creating a derivative data set including a plurality of derivative data points based on the image, determining an image gradient data point for each of the plurality of derivative data points, determining a target location of the fluid sample on the solid medium based on the image gradient data points, and removing image defects from the image.

[0066] In step 106, the control unit 30 uses the target position determined in step 104 by detecting, for example, light intensity or other values ​​at the target position and / or in a designated area around the target position. In an embodiment, the target position can be used as a center point to form a designated area around the target position. For example, the target position can be used to create a read area, which is used to detect the signal from the light projected onto the solid medium 10. The U.S. Provisional Application No. 62 / 693,120 entitled "Dry Slide Assay Using Reduced Reading Window" submitted on July 2, 2018 further describes a method for creating a read area around the target position, and is incorporated herein by reference and relied upon. In other embodiments, the target position can be used, for example, for aligning instrument metrology systems and / or optical devices, predicting maintenance intervals and / or minimizing spectral errors due to reaction cell interference.

[0067] In step 108, the control unit 30 calculates the average light intensity of the image signal, for example, based on the light projected onto the solid medium 10 within the target position and / or the reading area created from the target position. In an embodiment, the average light intensity is the sum of the AD count values ​​within the reading area, divided by the total area (total number of pixels) of the reading area.

[0068] At step 110, the control unit 30 uses the target position to calculate a response. For endpoint assays (e.g., UREA), the response can be calculated by the difference in signal between two different readings of the same slide or solid medium 10. For rate assays (e.g., AST), the response can be calculated by the rate of change of signal over time from multiple readings of the same single slide or solid medium 10. Since the orientation of the slide or solid medium 10 may change slightly over time due to rotation of the incubator, it is desirable to find the target position for each image on the same slide medium 10 over time.

[0069] At step 112, the control unit 30 performs the determination by calculating the concentration of the fluid sample, for example, using a calibration curve related to the response to the concentration. The calibration curve can be obtained during the calibration process using a fluid with a known concentration and the response corresponding to the concentration obtained. In the calibration curve, the concentration is a known response function. In an embodiment, the control unit 30 can perform a variety of different determinations using target locations from multiple images.

[0070] Fig. 9A 9B shows method 200, which illustrates step 104 of method 100 in more detail. Specifically, Fig. 9A and FIG. 9B illustrate a specially designed algorithm to detect the target position ( Fig. 9A ) and process image defects (e.g., repair image defects or report errors) ( FIG. 9B ), which improves measurement accuracy and reduces measurement bias and outliers. As explained in more detail below, when detecting the target position ( Fig. 9A ), using the first derivative of the image with a specific step size to obtain the image gradient. A threshold is then applied to remove high gradient areas. Finally, the centers of the remaining pixels in the image are used as the target locations.

[0071] After finding the target location (e.g., the center of a homogeneous region with minimal variation and highest signal), the image quality may be checked by checking the distance between the target location and the synchronization location, detecting the number of spikes associated with the target location, and analyzing the axial symmetry and noise level of the target location (FIG. 9B). If one or more or the amount of checks exceeds a determination-specific threshold, an error code may be issued for the image, indicating that method 100 should be restarted with a new fluid sample because the fluid sample being analyzed may be considered unreliable. If no errors are found, the average light intensity of the image at the target location may be calculated as discussed above. In some embodiments, if the number of spikes is below a threshold, method 200 is configured to remove spikes from the image, thereby improving the repeatability of the determination system. However, if the number of spikes is greater than a threshold, the image may be discarded or may be associated with an error code and / or an alarm.

[0072] It should be understood by those skilled in the art that the present invention may be omitted without departing from the spirit and scope of the present invention. Fig. 9A 9B, and / or additional steps may be added, and / or the order of certain steps may be rearranged. As with method 100, it should be understood that control unit 30 may include a processor and stored instructions to implement Fig. 9A 9B. The processor executes the instructions to cause the elements of the assay system 20 to perform the disclosed steps.

[0073] Step 200 begins at Figure 8 The image recorded by the imaging device 22 at step 102 of the present invention. In step 200, the control unit 30 analyzes the image by associating the image with metadata, such as the type of assay, the default center 40 of the fluid sample, the type of pattern detected for the fluid sample (e.g., concave, convex, complex), etc. The parameters stored in the metadata can be pre-programmed and stored in the memory of the control unit 30, or can be input by a user for a specific assay. The default center 40 of the fluid sample can be, for example, the center of the solid medium 10 or the center of the assigned position where the center of the fluid sample is expected to be located.

[0074] The type of pattern detected for a fluid sample may be flat or non-flat (e.g., concave, convex, or more complex shapes) depending on, for example, sensitivity to redistribution of soluble material in solid medium 10, analyte / reagent concentration, and / or chemical kinetics. Fig.10 Different example patterns formed by the fluid dispensed on the solid medium 10 are shown, and Fig.11 Views showing the original image and the first spatial derivative for different determinations are illustrated. Fig.10 and Fig.11 A small value is shown at a stagnant region 44. As illustrated, a fluid sample may have, for example, a stagnant region 44 with a very small gradient (e.g., peak or valley intensity), a washout region with a larger gradient, and / or an edge with a large gradient (from a wet-dry interface or slide frame). U.S. Provisional Application No. 62 / 693,120, filed on July 2, 2018, entitled "Dry Slide Assay Using Reduced Reading Window," further describes how washout regions can affect images and cause large gradients, the description of which is incorporated herein by reference and relied upon. According to the present method, when an appropriate threshold is applied, all large gradient regions can be removed and a stagnant region 44 can be identified.

[0075] At step 202, if the image is not already in this form, the control unit 30 normalizes the image by converting it into a flat field image. In an embodiment, normalizing the image includes normalizing the light energy applied across the reading area to reduce errors. In an embodiment, normalization has two steps. The first step includes subtracting the dark read signal from the original signal. The dark read signal is a digital signal from the CCD sensor when the light source is turned off. This calculation minimizes background digital noise. The second step is to normalize the dark correction signal using the flat field signal by multiplying the signal by a flat field function. The flat field function can be obtained by reading a standard surface, which is a uniform, flat, white and / or reflective surface. The flat field function can be a function that generates a value of "1" across the entire surface for the standard surface. Assume that the measured light intensity distribution is f = f (x, y), then the flat field is F =1 / f .

[0076] At step 204, the control unit 30 determines or accepts assay-specific parameters, such as image cropping size, step length, threshold parameters, etc. The assay-specific parameters may be pre-programmed and stored in the memory of the control unit 30, or may be input by a user for a particular assay. The image cropping size may be, for example, the expected size of the image to be cropped at step 206, and may be input or automatically generated by the control unit 30. In an example embodiment, the diameter of the image cropping size may be approximately 4.5 mm around a center point (e.g., a default center 40). Step length and threshold parameters are similarly input, or predetermined values ​​are used for subsequent steps of the process. Each assay may have its own cropping size, step length, and threshold value (e.g., URIC cropping size = 3.64 mm, step length 0.28 mm, and threshold value = 10).

[0077] At step 206, the control unit 30 crops an area 46 of the image. In the example, the control unit 30 crops an area 46 based on the expected position of a default center 40 of the fluid sample on the solid medium 10. In an embodiment, it is known from step 200 that the default center 40 is, for example, the center of the solid medium 10 or the center of an assigned position where the center of the fluid sample is expected. Therefore, the image can be cropped, for example, to a circle around the default center 40 (e.g., a circle with a diameter of 4.5 millimeters ("mm")) based on the image crop size determined in step 204. In another embodiment, the image can be cropped based on the detected light intensity without being limited to any particular size. U.S. Provisional Application No. 62 / 693,120, entitled "Dry Slide Assay Using Reduced Reading Window," filed on July 2, 2018, further describes how to crop an area of ​​an image to create a reading area, the description of which is incorporated herein by reference and relied upon.

[0078] At step 208, the control unit 30 records the default center 40 of the cropped image. In an embodiment, the default center 40 is known from step 102, and the image is cropped based on the default center 40. In another embodiment, the default center 40 may not correspond to the center of the cropped image, and may be determined based on a new cropped image. For example, the image may be cropped based on light intensity at step 206, and then the default center 40 may be recorded as the geometric center of the cropped image.

[0079] In steps 210 to 214, the control unit 30 creates a derivative data set including a plurality of derivative data points based on the cropped image. In an embodiment, the derivative data points may be first-order derivatives based on the colors in the image, and may each include image gradient data points defining a binary image. In an embodiment, the colors in at least one image represent light intensity. In an embodiment, the first-order derivative is the image light intensity in space. For example, each pixel in the image has a unique light intensity measured by an AD count (i.e., ADC). The first-order derivative may be the difference in light intensity between pixels at a predefined distance divided by the distance between the pixels.

[0080] At step 210, the control unit 30 creates a derivative data set by obtaining the absolute value of the first derivative (e.g., slope) of the cropped image at the measurement-specific step size determined at step 204. The first derivative may be calculated within the cropped image using the measurement-specific step size using a center difference method. For example, the derivative data set may be determined using the following formula:

[0081] Slope1=max(|du / dx|, |du / dy|).

[0082] Here, u is the light intensity (AD counts) at a pixel in the image. x and y are the coordinate position of the pixel. The slope can be calculated in both x and y directions, and the maximum absolute value can be defined as the slope. The step size for calculating the derivative is assay specific. As explained in more detail below, if Slope1 is less than a threshold, its quality value is "1", otherwise, its quality value is "0".

[0083] At steps 212 and 214, the control unit 30 determines an image gradient data point for each of the plurality of derivative data points in the derivative data set, thereby generating a binary image. In an embodiment, at step 212, if the Slope1 determined at step 210 is greater than a threshold value specified in the determination, the control unit 30 sets the image gradient data point to zero (0). That is, pixels with higher gradients are set to zero (0), removing peaks, edges, etc. from the binary image. Then, at step 214, if the image gradient data point is greater than the value of zero (0), the control unit 30 sets the image gradient data point to a value equal to one (1). That is, if Slope1 exceeds the threshold, the image gradient data point at each pixel position (e.g., the quality at a position in the binary image) is zero (0), and if Slope1 is below the threshold, it is one (1). In an embodiment, a first image gradient data point having a lower image gradient than a second image gradient data point is included or set to one (1), and / or (ii) a second image gradient data point having a higher image gradient than the first image gradient data point is excluded or set to zero (0).

[0084] At step 216, the control unit 30 determines a target position (e.g., elliptical or circular) of the fluid sample based on the image gradient data points. For example, the target position can be calculated as a binary image (e.g., Fig. 9A In an embodiment, the center position can be obtained using the following formula:

[0085]

[0086] In the formula, mass m ij is its position index i and j Function of . Coordinate value x ij and y ij Also a position index i and j The quality is equal to a value of "1" or a value of "0", depending on whether the quality is within the threshold across all indices. Center X c The coordinates are obtained by dividing the mass by the corresponding xThe center is calculated by summing the products of the coordinates and then dividing the sum by the total mass. Y c The coordinates are obtained by dividing the mass by the corresponding y It is calculated by summing the products between the coordinates and then dividing the sum by the total mass.

[0087] The centroid of the binary image can then be designated as a target location of the fluid sample on the solid medium 10 , which is the approximate geometric center of a homogeneous region of the fluid sample on the solid medium 10 .

[0088] In steps 218 to 252 of FIG. 9B , the control unit 30 is configured to detect and / or remove defects from the image (e.g., due to blemishes in the image, dust, coating defects, wicking, foreign matter, bubbles, scratches, etc.) and / or determine an error condition based on the target location (i.e., the center of the fluid sample determined from step 216). The error may also indicate a problem with the reflectometer illumination system of the measurement system 20, such as dirty projector optics. For example, Fig.12 As shown, there are many different imperfections in the image (e.g., dust, off-center dispensing, wicking, foreign matter, bubbles, scratches, etc.) that can negatively impact the assay.

[0089] At step 218, the control unit 30 compares the target position determined at step 216 with the previously determined default center 40. In an embodiment, if the distance between the default center and the target position is greater than a threshold, the control unit 30 may report an error at step 220 and end the analysis at step 222. This may mean that the method 100 should then be restarted with a new fluid sample, since the fluid sample being analyzed is considered unreliable.

[0090] At step 224, the control unit 30 considers whether the flatness of the image is less than a threshold value. In an embodiment, the flatness of the image is the maximum linear slope (absolute value and normalized by the ADC mean) of two linear slopes across the central vertical and horizontal lengths of the cropped image. Since the AD count value (ADC) varies over a large range (e.g., from 1,000 to 50,000) depending on the analyte concentration in the sample, the AD count value is normalized by dividing the AD count value by its mean value. In this way, the slope variation is more related to flatness than to the analyte concentration. The average value of the AD count is obtained, and then the AD count value is divided by the average value. The slope can be positive or negative, because the absolute value of the slope is used to determine whether the image is flat. Although the light intensity distribution of the image may be concave or convex, its center (distribution position) is axisymmetric.

[0091] If at step 226 the flatness of the image is less than the threshold, the control unit 30 may report an error at step 228 and end the analysis at step 222. This may indicate that the method 100 should then restart with a new fluid sample because the fluid sample being analyzed is deemed unreliable.

[0092] At step 230, the control unit 30 creates a first-order derivative of the cropped image at a determined step size (eg, a step size of one (1)). For example, the first-order derivative data may be determined using the following formula:

[0093] Slope2=|du / dx|+|du / dy|.

[0094] In step 232, the control unit 30 obtains the mean value (MEAN) and the standard deviation (SD) of Slope2 within the new center region. In step 234, the control unit 30 determines whether the standard deviation / mean value is below a threshold value. If the standard deviation / mean value is below a threshold value, the control unit 30 may report an error in step 236 and end the analysis in step 238. This may mean that the method 100 should then be restarted with a new fluid sample because the fluid sample being analyzed is considered unreliable.

[0095] At step 240, the control unit 30 may define two assay-specific constants: SpikeValueMax and n In an embodiment, SpikeValueMax represents the value determined by the assay performance experiment and is provided for each assay, while n Represents a positive number and is used to calculate the spike detection threshold SpikeGradientLimit Then, the control unit 30 can use, for example, the following formula to define SpikeGradientLimit :

[0096] SpikeGradientLimit =min( SpikeValueMax , MEAN+ n *SD).

[0097] In the above formula, SpikeValueMax and MEAN+ n *The minimum SD value was used to define the threshold SpikeGradientLimit , the threshold is used to detect whether the slope exceeds the limit in the image reading area.

[0098] In steps 242 and 244, control unit 30 removes large gradient peaks from the cropped image. In the exemplary embodiment, the peaks are defined by SpikeMask Removed, if the Slope1 of a point is greater than SpikeGradientLimit ,but SpikeMaskis equal to zero (0), and if a point's Slope1 is less than SpikeGradientLimit ,but SpikeMask A value equal to one (1). In another embodiment, spikes may be removed based on being above or below a predetermined threshold.

[0099] In step 246, the control unit 30 determines the total number of peaks detected in steps 240 and 242. If a small number of peaks are detected and the peaks are removed from the image, the remaining pixels in the image can still be used to calculate the signal of the solid medium 10. However, if the number of peaks detected based on the assay exceeds a predefined limit, the control unit 30 may report an error in step 248 and end the analysis in step 252. This may mean that the method 100 should then be restarted with a new fluid sample because the fluid sample being analyzed is considered unreliable.

[0100] At step 250 , control unit 30 integrates within the cropped image defined by the target location, removing the detected defects so that the resulting image can be used in step 106 of method 100 .

[0101] Fig.13 An example of how a speck of dust on the solid medium 10 may cause a spike in the corresponding image is shown. As shown, by removing the spike, any bias in the determination made using the image may also be removed, making the determination more reliable.

[0102] Fig.14 and Fig.15 The advantages achieved by the presently disclosed method are illustrated. Fig.14 In the , TPxt means that the assay is TP ("total protein") in a multiplex format (two assays per slide). COM (shown as circles) represents the precision when reading at the target position, which is found using the currently disclosed method. PS (shown as squares) represents the precision when reading at a pre-specified center (e.g., a hypothetical dispensing position) without knowing the actual dispensing position. The coefficient of variation (CV%) for each reading diameter is the average of all tested samples.

[0103] Fig.16 The present invention illustrates an exemplary embodiment of the present invention. Figures 1 to 5 Embodiment of the solid medium 10. Fig.16Solid medium 10 comprises: two chemical chips 1602a and 1602b corresponding to the above-mentioned stagnant area 44. As discussed, the stagnant area corresponds to the area directly below the opening of the fluid metering tip of the chemical chip. The stagnant area 44 can also be characterized by having very little fluid flow or no fluid flow in the radial direction. In the case of being positioned radially outward from the center of the point and the area, there is a fluid flow vector pointing outward from the center of the chemical chip. A certain amount of chemical chip reagents are washed out in this area. Once the chemical reaction is completed, the stagnant area or area 44 will not experience this wash out, and different optical densities may be present, compared to the area outside the stagnant area 44. In some examples, the stagnant area or area 44 does not have a significant level of radial fluid flow, which produces an area of ​​low optical variability and an area where a high indicator (dye) exists.

[0104] In some instances, chemical chip and / or stagnant area 44 correspond to the target position of fluid sample in reaction pool.Target position or chemical chip correspond to the position where indicator reaction occurs, so that when the target molecule in fluid sample reacts with the reagent in reaction pool, indicator development is to be displayed.In some examples, chemical chip 1602a and 1602b can all include reaction cuvette that is full of liquid.In these examples, the imaging of reaction cuvette may show bubbles, debris and / or scratches on cuvette wall.With respect to analysis and determination result, identified defects can be identified and their influence can be mitigated.

[0105] The use of chemical chips 1602 reduces the area required for the sample and enables more than one sample to be distributed on the slide. Each chemical chip 1602 can receive the same fluid from the sample to enable the same or different analyses to be performed using the same solid medium 10. Alternatively, the chemical chips 1602 can each receive different fluids to enable the same or different analyses to be performed using the same slide 10. In addition, although Fig.16 Two chemical chips 1602 are shown, but in other examples, the solid medium 10 may include additional chemical chips, such as three, four, etc. It should be appreciated that including more than one chemical chip on the solid medium 10 can improve the operating efficiency of the assay system 20 because multiple analyses can be performed on the same solid medium 10 without moving the solid medium. In contrast, a solid medium having only a single chemical chip requires processing two or more separate solid media to perform the same analysis as a single solid medium 10 having multiple chemical chips.

[0106] Fig.16An example of a solid medium combination of chemical products is also shown. The combination includes: triglyceride cholesterol (TRI-CHOL), total bilirubin alkaline phosphatase (TBIL-ALKP), alanine aminotransferase-aspartate aminotransferase (ALTV-AST), urea creatinine (UREA-CREA), glucose calcium (GLU-CA) and total albumin (ALB-TP). It should be appreciated that other combinations can be created and implemented on the solid medium 10.

[0107] Fig.17 The example embodiment according to the present disclosure is shown. Figure 3 The image recorded by the measuring system includes a sample placed on the chemical chip 1602 of the corresponding solid medium 10. As discussed above, the distribution of the fluid sample creates a liquid lens 46 on the chemical chip 1602. Fig.17 The example solid medium 10 is configured to reduce sample size and improve the operating efficiency of the assay system 20 while maintaining analytical performance compared to known conventional single slide tests. Since the sample volume placed in each chemical chip 1602 is smaller, the size of the area used for analytical measurement is reduced. In some examples, the assay system 20 can use digital chemistry technology, as discussed above, to mitigate possible performance sensitivity. Fig.17 As shown, digital chemistry uses wavelength-specific LEDs to record or capture images of solid media 10 on a digital image reflectometer. The assay system 20 uses one or more imaging algorithms to improve chemistry results by ensuring that the optimal area of ​​the sample is analyzed (as discussed above), even in the presence of variations in metrological orientation or the inclusion of contaminants (e.g., dust).

[0108] like Fig.17 As shown, the measurement system 20 uses an imaging algorithm to determine the center 40, which is shown as the center 40a to 40d of the corresponding chip 1602a to 1602d. As discussed above, the center 40 can be the same as or different from the default center, which is the theoretical point center if the dispensing tip and the slide are perfectly aligned. The measurement system 20 then analyzes a certain radius around the center 40. The radius is between 1 mm and 8 mm, preferably about 2.25 mm, as shown by the dotted line in the figure.

[0109] Fig.18 The example embodiment according to the present disclosure shows Figure 3 An image 1800 recorded by the measuring system 20 wherein dust or another contaminant 1802 is included in the sample. Fig.19 The method disclosed herein is used by the measuring system 20 to measure Fig.18The first graph 1902 shows the results of the analysis before the anomaly 1802 is detected and removed. The second graph 1904 shows the results of the analysis after the anomaly 1802 is detected and removed. In the illustrated example, the imaging algorithm detects the anomaly and removes it from the processed image 1906 (derived from Fig.18 The anomaly is removed from the image 1800 of the sample. As a result, the anomaly is not included in the subsequent analysis of the sample. In some examples, the measurement system 20 removes the anomaly by changing the pixel color associated with the anomaly to a color consistent with the surrounding pixel colors or a pixel color indicating that there is no data for subsequent analysis.

[0110] Fig. 20 The example embodiment according to the present disclosure shows Figure 3 Another image 2000 recorded by the measuring system 20, wherein dust or another contaminant is included in the sample. Fig.21 21 shows the analysis performed on the sample by the measurement system 20. The first graph 2102 shows the analysis results before the anomaly is detected and removed. The second graph 2104 shows the analysis results after the anomaly is detected and removed. Similar to the previous example, the imaging algorithm detects the anomaly and removes it from the processed image 2106 (derived from Fig. 20 The anomaly is removed from the image 2100 of FIG. 2000 . As a result, the anomaly is not included in subsequent analysis of the sample. Additionally, the determination system 20 is configured to move the center 40 of the image 2106 so that it reduces or minimizes the number of anomaly-corrected locations included within the analysis field (e.g., a circle around the center).

[0111] Figures 22 to 37 The test result data is shown, which will Figures 1 to 21 The analytical performance of the example solid medium 10 is compared with known slides or solid media. Fig. 22 and Fig.23 In the illustrated example of the assay system 20, a solid medium 10 is analyzed while a known conventional assay system is used to analyze a known slide or solid medium. In the example, six of the example solid media 10 for two serum concentrations are evaluated using quality control materials on the example assay system 20. Following the CLSI EP05 guidelines, the overall intra-laboratory performance accuracy (reported as a percentage of variance (%CV)) of a single calibration is evaluated for a total of 80 replicates, with two replicates per run over twenty days, with two runs per day. The worst-case intra-laboratory accuracy of the example solid media 10 analyzed by the assay system 20 is compared to a corresponding single prior art test slide analyzed using a conventional assay system.

[0112] %CV corresponds to the ratio of the standard deviation of the sample data to the mean, which provides an indication of the precision and repeatability in the assay, with lower values ​​corresponding to higher precision and repeatability.

[0113] Fig. 22 Illustrated is a graph of a table 2200 showing two serum levels of each slide chemistry (UREA, TRIG, GLU, ALB, TBIL, ALTV, CREA, CHOL, CA, TP, ALKP, and AST) and the corresponding %CV for a prior art slide using a conventional assay system and an example solid medium 10 using the example assay system 20. As illustrated, of the twenty-four different tests, the solid medium 10 using the assay system 20 had a lower %CV for nineteen of the twenty-four different tests. Fig.23 A graph 2300 is shown illustrating the difference in %CV for each of the different slide chemistries tested between known prior art slides and the example solid media 10 disclosed herein analyzed using the assay system 20. As shown, using the example solid media 10 with the assay system 20 provided better %CVs for most slide chemistries compared to the prior art slides.

[0114] exist Figures 24 to 37 In the illustrated example of , an external precision study was performed. In this study, prior art slides were analyzed using a conventional assay system. Test slides with twelve chemical compositions were analyzed for two serum concentrations. Statistical outliers were removed based on the analysis. The remaining data were subjected to a Shapiro-Wilk normality test, where sets that showed severe deviations from normality were removed. The %CV was calculated for each slide serum-reagent lot combination. The %CV metric was averaged within the reagent lot, and the %CV metric was compared to the worst case intra-laboratory precision of the example solid medium (10) analyzed by the example assay system 20.

[0115] Fig.24 Illustrated is a graph of a table 2400 showing two serum levels of each slide chemistry (UREA, TRIG, GLU, ALB, TBIL, ALTV, CREA, CHOL, CA, TP, ALKP, and AST) and the corresponding %CV for a prior art slide using a conventional assay system and an example solid medium 10 using the example assay system 20. As illustrated, in the twenty-four different tests, the solid medium 10 using the assay system 20 had a lower %CV for twenty of the twenty-four different tests. Fig.25Graph 2500 is shown illustrating the %CV differences for each of the different slide chemistry tests between known prior art slides analyzed using assay system 20 and the example solid media 10 disclosed herein.

[0116] Figures 26 to 37 A graph is shown illustrating the results for each reagent lot number for an example solid medium 10 and a known prior art slide. In the graph, three lots of solid medium 10 are provided and are referred to as "XT ... Lot #". In addition, data related to the prior art slide are referred to as "ST from field ..." and "ST average". Each graph provides the precision %CV for each serum (PVI) and (PVII).

[0117] Fig.26 Graph 2600 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the TRIG slide chemistry as compared to the prior art slide analyzed by the conventional assay system. Fig. 27 Graph 2700 shows that the example solid media 10 analyzed by the assay system 20 had lower %CVs for the CHOL slide chemistries, with the exception of the PVI serum from Lot 3, which had a slightly higher %CV compared to the known prior art slides analyzed by the conventional system. Fig.28 Graph 2800 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the GLU slide chemistry as compared to the prior art slide analyzed by the conventional assay system. Fig.29 Graph 2900 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the CA slide chemistry as compared to the prior art slide analyzed by the conventional assay system.

[0118] in addition, Fig.30 Graph 3000 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the TP slide chemistry as compared to the prior art slide analyzed by the conventional assay system. Fig.31 Graph 3100 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the ALB slide chemistry compared to the prior art slide analyzed by the conventional assay system. Fig.32 Graph 3200 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the ALTV slide chemistry as compared to the prior art slide analyzed by the conventional assay system. Fig.33Graph 3300 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the AST slide chemistry compared to the prior art slide analyzed by the conventional assay system.

[0119] Fig.34 Graph 3400 shows that the example solid media 10 analyzed by the assay system 20 has a higher %CV of the UREA slide chemistry than the prior art slide analyzed by the conventional assay system. However, the difference in %CV between the example system and the conventional system is less than 0.5%. Fig.35 Graph 3500 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the CREA slide chemistry as compared to the prior art slide analyzed by the conventional assay system. Fig.36 Graph 3600 shows that the example solid media 10 analyzed by the assay system 20 has approximately equal or lower %CV of the ALKP slide chemistry than the prior art slide analyzed by the conventional assay system. Fig.37 Graph 3700 shows that the example solid media 10 analyzed by the assay system 20 has a lower %CV of the TBIL slide chemistry compared to the prior art slide analyzed by the conventional assay system.

[0120] in conclusion

[0121] It should be understood that various changes and modifications to the currently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. Therefore, it is intended that such changes and modifications be covered by the appended claims.

[0122] Unless otherwise stated, all the numbers used in the specification and claims to express the amount of ingredients, properties (such as molecular weight, reaction conditions, etc.) are to be understood as modified by the term "about" in any case. Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and the appended claims are approximate values, which may vary depending on the desired properties sought to be obtained by the present disclosure. At least, and without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted according to the number of reported significant figures and by applying ordinary rounding techniques. Although the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximate values, the numerical values ​​set forth in the specific examples are reported as accurately as possible. However, any numerical value inherently contains certain errors that are necessarily obtained from the standard deviation found in its corresponding test measurement results.

[0123] Unless otherwise indicated herein or clearly contradictory to the context, the terms "one" and "an" and "the" and similar references used in the context of the present disclosure (especially in the context of the appended claims) are to be interpreted as covering both the singular and the plural. The enumeration of the range of values ​​herein is intended to be used as a shorthand method to refer to each individual value falling within the range individually. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it is quoted individually herein. Unless otherwise indicated herein or clearly contradictory to the context in other ways, all methods described herein can be implemented in any suitable order. The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended only to better illustrate the present disclosure and is not intended to limit the scope of the present disclosure otherwise claimed. Any language in the specification should not be interpreted as indicating any unclaimed elements that are essential to the practice of the present disclosure.

[0124] Unless explicitly indicated to refer to only alternatives or the alternatives are mutually exclusive, the use of the term "or" in the claims means "and / or," although the present disclosure supports a definition referring only to alternatives and "and / or."

[0125] The grouping of alternative elements or embodiments of the present disclosure disclosed herein is not to be construed as limiting. Each group member may be quoted or claimed individually, or may also be used in combination with other members of the group or other elements found herein. It is expected that one or more members in the group may be included in the group or deleted from the group for convenience and / or patentability reasons. When any such inclusion or deletion occurs, the specification is considered to contain the modified group in this article, so the written description of all Markush groups used in the appended claims is met.

[0126] Preferred embodiments of the present disclosure are described herein, including the best mode known to the inventor for carrying out the present disclosure. Of course, after reading the above description, changes to those preferred embodiments will become apparent to those of ordinary skill in the art. The inventor expects that those of ordinary skill in the art will adopt such changes as appropriate, and the inventor wishes to practice the present disclosure in a manner different from that specifically described herein. Therefore, the present disclosure includes all modifications and equivalents of the subject matter recorded in the appended claims permitted by applicable law. In addition, unless otherwise indicated herein or otherwise clearly contradictory to the context, the present application covers any combination of the above elements in all possible variations thereof.

[0127] Certain embodiments disclosed herein may be limited in the claims using consisting of language or consisting essentially of language. When used in a claim, whether filed by amendment or addition, the transition term "consisting essentially of" excludes any elements, steps, or ingredients not specified in the claim. The transition term "consisting essentially of" limits the scope of the claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic(s). Embodiments of the present disclosure so claimed are inherently or expressly described and enabled herein.

[0128] In addition, it is to be understood that the embodiments of the present disclosure disclosed herein are illustrations of the principles of the present disclosure. Other modifications that may be adopted are within the scope of the present application. Therefore, as an example and not a limitation, alternative configurations of the present disclosure may be utilized according to the teachings herein. Therefore, the present disclosure is not limited to exactly as shown and described.

Claims

1. A method of performing at least one assay, comprising: In the control unit, an image of the fluid sample located on the reaction pool is obtained; determining, via the control unit, a default center corresponding to at least one of: a center of the reaction well or a center of a dispensing location of the fluid sample onto the reaction well; creating, via the control unit, a derivative data set comprising a plurality of derivative data points based on the image; An image gradient data point is determined, via a control unit, for each of the plurality of derivative data points to create a binary image by: comparing each of the plurality of derivative data points to a threshold value; Assigning a value of "0" to image gradient data points corresponding to derivative data points having a value greater than a threshold value to remove unwanted image artifacts, and Assign the value "1" to the remaining image gradient data points; determining, via the control unit, a centroid of the binary image using the image gradient data points; designating, via the control unit, the determined center of mass as a target position of the fluid sample in the reaction cell; Comparing the target position with a default center via the control unit; as well as When the distance between the default center and the target position is less than a threshold, at least one measurement is performed at the target position in the reaction pool using the fluid sample via the control unit and the associated measurement system.

2. The method according to claim 1, wherein The reaction cell includes a solid medium.

3. The method according to claim 2, wherein: The reaction pool includes a dry slide or a reaction cuvette.

4. The method according to claim 1, wherein The target location includes the center of the homogenous region of the fluid sample in the reaction cell. The method of claim 1 , comprising performing multiple measurements using target locations from multiple images.

6. The method according to claim 1, wherein The plurality of derivative data points are based on first derivatives of colors in the at least one image.

7. The method according to claim 1, wherein Determining the target location of the fluid sample includes at least one of: (i) using a first image gradient data point having a lower image gradient than a second image gradient data point; or (ii) excluding second image gradient data points having a higher image gradient than the first image gradient data points. The method of claim 1 , comprising removing image defects from the image via the control unit.

9. The method according to claim 1, wherein The image is a two-dimensional image.

10. The method according to claim 1, comprising forming a reading zone around the target location via a control unit, and wherein Performing at least one assay includes using a read zone.

11. The method according to claim 1, wherein Determining the target location of the fluid sample includes detecting or measuring an indicator reaction of an indicator molecule in a reaction well formed by a combination of at least one reagent and the fluid sample.

12. The method of claim 1, further comprising reporting an error via a control unit when the distance between the default center and the target position is greater than or equal to a threshold, the error indicating that a new fluid sample should be dispensed on a new reaction well.

13. A method of performing at least one assay, comprising: obtaining, via a control unit, an image of the fluid sample located on the reaction pool; determining, via the control unit, a default center corresponding to at least one of: a center of the reaction well or a center of a dispensing location of the fluid sample onto the reaction well; creating, via the control unit, a derivative data set comprising a plurality of derivative data points based on the image; An image gradient data point is determined, via a control unit, for each of the plurality of derivative data points to create a binary image by: comparing each of the plurality of derivative data points to a threshold value; Assigning a value of "0" to image gradient data points corresponding to derivative data points having a value greater than a threshold value to remove unwanted image artifacts, and Assign the value "1" to the remaining image gradient data points; determining, via the control unit, a centroid of the binary image using the image gradient data points; designating, via the control unit, the determined center of mass as a target position of the fluid sample; forming a reading area around a target location via a control unit; Comparing the target position with a default center via the control unit; as well as When the distance between the default center and the target location is less than a threshold, at least one measurement is performed using the read region via the control unit and the associated measurement system.

14. The method according to claim 13, wherein The reaction cell includes a solid medium.

15. The method according to claim 14, wherein The reaction pool includes a dry slide or a reaction cuvette.

16. The method according to claim 13, wherein The read area appears circular in at least one of the images.

17. The method according to claim 13, wherein: The read zone appears to be elliptical in at least one of the images.

18. The method of claim 13, comprising: Via a control unit and associated measurement system, multiple measurements are performed using the target positions from the multiple images.

19. The method according to claim 13, wherein The image is a two-dimensional image.

20. An apparatus for performing at least one assay, comprising: a slide receiving location configured to receive at least one reaction well having a fluid sample located thereon; as well as an imaging device positioned and arranged relative to the slide receiving location to obtain an image of the fluid sample located in the reaction well; as well as A control unit configured to: determining a default center corresponding to at least one of: a center of a reaction well or a center of a dispensing location of a fluid sample onto a reaction well, Creating a derivative data set including a plurality of derivative data points based on the image, An image gradient data point is determined for each of the plurality of derivative data points to create a binary image by: comparing each of the plurality of derivative data points to a threshold value; Assigning a value of "0" to image gradient data points corresponding to derivative data points having a value greater than a threshold value to remove unwanted image artifacts, and Assign the value "1" to the remaining image gradient data points, Use image gradient data points to determine the centroid of a binary image, The determined centroid is designated as the target position of the fluid sample in the reaction cell. Compare the target position to the default center, and When the distance between the default center and the target location is less than a threshold, at least one measurement is performed based on the target location.

21. The device according to claim 20, wherein The reaction cell includes a solid medium.

22. The device according to claim 21, wherein The reaction pool includes a dry slide or a reaction cuvette.

23. The device according to claim 21, wherein The solid medium includes a second reaction cell.

24. The apparatus according to claim 20, wherein The target location includes the center location of the homogenous region of the fluid sample.

25. The apparatus according to claim 20, wherein The control unit is configured to determine the target position by at least one of: (i) using a first image gradient data point having a lower image gradient than a second image gradient data point; or (ii) excluding a second image gradient data point having a higher image gradient than the first image gradient data point.

26. The apparatus according to claim 20, wherein The control unit is configured to determine a target position at a geometric center of a first image gradient data point having a lower image gradient than a second image gradient data point.

27. The apparatus according to claim 20, wherein The control unit is configured to perform a plurality of different determinations using the target location from the plurality of images.

28. The apparatus according to claim 20, wherein The target position of the fluid sample in the reaction pool corresponds to the position where the indicator reaction occurs, so that when the target molecules in the fluid sample react with the reagents in the reaction pool, the indicator develops to display.

Images