Colorimetric tool and colorimetric method

Abstract

To provide a colorimetric tool capable of contributing to stabilizing the quality of images used for a remote inspection.SOLUTION: A colorimetric tool 1 which is used while a test kit having a coloration part attached includes: a principal surface 2; a scaffold part 20 configured to hold the principal surface at an angle to an installation surface; and a chart part 30 formed on the principal surface and having a color chart 31. The colorimetric tool 1 is configured so that the coloration part is held to be visible from the principal surface side when the inspection kit is attached.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a color measurement tool, and more particularly to a color measurement tool used for acquiring images for determining the color development of various test kits. The present invention also relates to a color measurement method using the color measurement tool. [Background technology]

[0002] The emergence of the novel coronavirus has caused strain on medical facilities, accelerating the spread of telemedicine. As part of telemedicine, medical antigen test kits are sold at pharmacies and other outlets, and so-called remote testing is becoming more widespread, in which patients take pictures of themselves and send them to the kit, and receive test results based on the images. In telemedicine, diagnosis is generally made by medical professionals looking at the images, but studies are also underway to have computers read the images and make automated diagnosis.

[0003] In tests at medical facilities, medical staff visually check the kit, allowing for accurate judgments, but in the above-mentioned remote medical tests, medical staff do not look at the kit directly, but rather view it as an image, so whether or not the image is properly captured has a large impact on the test results. Even in automatic judgments by computers, the quality of the image naturally affects the accuracy of the judgment.

[0004] In relation to this problem, Patent Document 1 discloses a color reaction judgment system equipped with white LED lighting and a camera. By illuminating with white LEDs and capturing an image with a camera, the accuracy of the computer judgment performed thereafter can be stabilized. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-163843 A Summary of the Invention [Problem to be solved by the invention]

[0006] The system according to Patent Document 1 is large-scale and equipped with lighting and a camera, so there is a limit to its widespread use. Furthermore, as will be described in detail later, the inventors discovered that there are other important factors to stabilize the quality of the captured image, and thus completed the present invention.

[0007] In view of the above circumstances, an object of the present invention is to provide a color measurement tool that can contribute to stabilizing the quality of images used in remote inspection. Another object of the present invention is to provide a color measurement method that contributes to performing remote inspection with stable accuracy. [Means for solving the problem]

[0008] A first aspect of the present invention is a color measurement tool for use with a test kit having a color development portion attached thereto. This color measurement tool includes a main surface, a base portion configured to be able to hold the main surface at an angle to an installation surface, and a chart portion formed on the main surface and having a color chart. The color measurement tool is configured so that, when the test kit is attached, the color-developing portion is held so as to be visible from the main surface side.

[0009] A second aspect of the present invention is a color measurement method using the color measurement tool according to the first aspect. In this color measurement method, a test kit having a color display portion is attached to a color measurement tool, and the color measurement tool is imaged from the main surface side with the main surface at an angle to the installation surface to obtain an image including the color display portion and the chart portion. A corrected image is created by correcting the image of the color display portion in the image using information about the chart portion in the image, and the state of the color display portion is determined based on the corrected image. Effect of the Invention

[0010] The color measurement tool according to the present invention can contribute to stabilizing the quality of images used for remote inspection. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of a test kit. [Diagram 2] FIG. 1 is a plan view showing a color measurement tool according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a side view of the assembled color measurement tool. [Figure 4] 13 is a diagram showing the color measurement tool with the test kit attached thereto as viewed from the normal direction of the main surface. FIG. [Diagram 5] 13 is a diagram showing a chart portion according to a modified example of the color measurement tool. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present invention will be described with reference to FIGS. First, an example of a test kit targeted by the color measurement tool according to the present invention is shown in Fig. 1. The test kit 100 shown in Fig. 1 has a specimen supplying section 101 and a color development section 102, and its basic structure is publicly known. When a specimen such as blood or a body fluid is placed in the specimen supplying section 101, the specimen moves inside and reacts with a reagent therein. If the specimen contains a target substance such as a virus, a line of a predetermined color appears at a predetermined position in the color development section 102. That is, in a test kit such as 100, the presence or absence of a line, its thickness, color, and the like are indicators of the judgment result, so it is important to obtain an image in which this is appropriately captured.

[0013] In remote testing, the subject takes a picture of the test kit 100 displaying the test results using a smartphone or the like to obtain an image. Since most subjects have no or little medical knowledge, they do not understand the importance of obtaining appropriate images as described above. Therefore, if subjects are allowed to freely obtain images without any restrictions, the likelihood of obtaining appropriate images is low. In a preliminary study conducted by the inventors, when multiple subjects were allowed to freely take pictures of the test kit, many images were found that could not be used for judgment, or that could be used for judgment but had problems with accuracy.

[0014] The inventors have studied various methods for obtaining images of a test kit with relatively stable quality even when an ordinary subject takes an image. As a result, they have found that the quality of the obtained image can be stabilized at a high level by having the subject take an image with the kit attached to the color measurement tool. The color measurement tool according to this embodiment will be described below.

[0015] Fig. 2 shows a plan view of the color measurement tool 1 according to this embodiment. The color measurement tool 1 shown in Fig. 2 is a rectangular sheet in plan view, and one surface of the color measurement tool 1 is a main surface 2 on the side to be imaged. The color measurement tool 1 is assembled into a three-dimensional shape for use, as will be described in detail later.

[0016] The color measurement tool 1 has a window portion 10 provided in the center, foothold portions 20 provided on the left and right sides of the window portion 10, and a chart portion 30 provided around the window portion 10. The window portion 10 in this embodiment is surrounded by discontinuous notches 11, and by hollowing out the area within the notches 11 during use, an opening (window) penetrating the color measurement tool 1 in the thickness direction can be formed. The dimensions of the window formed in the window portion 10 are set according to the target test kit. For example, when using the test kit 100, it is necessary that at least the area of ​​the color development portion 102 where a line appears can be placed within the window, and it is preferable that the dimensions are such that the entire color development portion 102 can be placed within the window. The window portion 10 is not limited to one in which the window is formed at the time of use, and may be distributed in a state in which the window is already formed.

[0017] The scaffolding portion 20 is a substantially right-angled triangular region surrounded by a fold line and a cut. The fold line is provided in a portion corresponding to the longer of the two sides excluding the hypotenuse, and the remaining portion is the cut. 2, the two scaffolding sections 20 are formed so that, with the folding line 21 positioned on the window section 10 side, the folding line 21 is approximately parallel to the same side of the planar shape of the color measurement tool 1, and the two scaffolding sections 20 are symmetrical with respect to the window section 10. As a result, the portions corresponding to the oblique sides of the scaffolding sections 20 are both positioned on the side farther from the window section 10.

[0018] Each fold line 21 is divided into two regions by a cut 22 provided in the middle. The cut 22 extends a certain length from both ends in a direction away from the window portion 10, and then extends approximately parallel to the fold line 21 and is connected thereto.

[0019] The chart unit 30 has a color chart 31 and a brightness chart 32. Both the color chart 31 and the brightness chart 32 are formed by printing or the like on the main surface 2. The chart unit 30 of this embodiment has a guide 33 used during image processing by a computer, but this is not essential and may be omitted.

[0020] A colored region 3 is provided with a constant width on the periphery of the main surface 2. Although details will be described later, the colored region 3 contributes to stabilizing the dimensions of the test kit in a captured image.

[0021] The operation of the color measurement tool 1 according to this embodiment configured as above when in use will be described taking the case where the test kit 100 is used as an example. The subject forms a window in the window portion 10. Furthermore, the two scaffold portions 20 are folded along the folding lines 21 approximately perpendicular to the main surface 2, so as to protrude to the side opposite the main surface 2.

[0022] The color measurement tool 1 with the scaffolding portion 20 protruding therefrom can be placed on an installation surface such as a table with the oblique side of the scaffolding portion 20 facing downward, i.e., with the main surface 2 facing upward. 3 shows the color measurement tool 1 installed with the oblique side facing downward, viewed from the side. When the color measurement tool 1 is placed with the scaffolding 20 in contact with the installation surface Gr, the main surface 2 rises at a predetermined angle relative to the installation surface Gr and is held non-parallel to the installation surface Gr. Furthermore, the notch 22 ensures a space for placing the test kit 100 below the window 10 between the window and the scaffolding 20.

[0023] The subject inserts the test kit 100 containing the sample from the side into the recess of one scaffold part 20 created by the cut 22, and passes it through the recess of the other scaffold part 20. After that, the position is adjusted as necessary, and when the color-changing part 102 is positioned within the window, the test kit 100 is attached to the color measurement tool 1 in a state where the color-changing part 102 can be seen through the window. In the assembled color measurement tool 1, the middle portion 22a of the notch 22 protrudes toward the main surface 2, so that the test kit 100 is supported by the color measurement tool 1 in a state of contact with the sub-surface 4 opposite to the main surface and the middle portion 22a. This configuration reduces resistance when inserting the test kit 100, while realizing stable support after installation.

[0024] In the above-described state, the test kit 100 is held on the secondary surface 4 side and does not protrude towards the primary surface 2. Therefore, the shadow of the test kit 100 is not cast on the primary surface 2. If the shadow of the test kit 100 cast on the primary surface 2 falls on part of the color chart 31 or the brightness chart 32, it may become impossible to properly correct the image using the chart portion 30; however, in the color measurement tool 1, the above-described manner in which the test kit is held makes it possible to almost completely prevent such a situation.

[0025] The subject brings an imaging device, such as a camera of a smartphone or the like, or a digital camera, close to the principal surface 2 from the normal direction of the principal surface 2. FIG. 4 shows the color measurement tool 1 to which the test kit 100 is attached, viewed from the normal direction of the principal surface 2. The subject brings the imaging device close enough that the colored region 3 is no longer present in the imaging field, and then captures an image of the principal surface 2 of the color measurement tool 1 together with the color presentation portion 102. By excluding the colored region 3 from the imaging field during imaging, it is possible to ensure that the color presentation portion 102 in the captured image is large enough to be judged.

[0026] The acquired image includes the image of the colored portion 102 including the state of the lines based on the sample, as well as the chart portion 30 captured under the same conditions. Therefore, the computer can appropriately correct the image of the colored portion 102 in the image based on the state of the chart portion 30. This can improve the accuracy of subsequent automatic judgment by the computer and judgment by medical personnel based on the image.

[0027] That is, the flow of the color measurement method using the color measurement tool 1 can be roughly summarized as follows. A test kit 100 having a color development section 102 is attached to the color measurement tool 1. The color measurement tool 1 is imaged from the principal surface 2 side with the principal surface 2 at an angle to the installation surface Gr, and an image including the color presentation portion 102 and the chart portion 30 is obtained. The colored portion 102 in the acquired image is corrected using the chart portion 30 in the image to create a corrected image. The state of the colored portion 102 (presence or absence of lines, darkness, etc.) is determined based on the corrected image.

[0028] The inventors attached the test kit to the color measurement tool 1 and used four different smartphones with two different camera settings (exposure adjustments) to capture a total of eight images. The brightness and color of the images varied depending on the model and settings, and no images were identical. However, for all images, automatic correction using a program could be performed without problems based on the chart information contained in the images. It was also confirmed that appropriate judgment results could be obtained for all corrected images, including lines of medium density, which are considered to be relatively difficult to judge.

[0029] In the above-mentioned preliminary study, there were many cases where subjects placed the test kit on a horizontal installation surface and captured the image from directly above. In images captured in this manner, the shadow of the imaging device is often cast on a part of the test kit. If such a shadow casts on a part of the chart, it may be difficult to correct as described above, and if the shadow casts on the color-producing part 102, it was found that the accuracy of determining the density of the line is reduced, or in the case of a faint line, the existence of the line itself cannot be recognized.

[0030] When the assembled color measurement tool 1 is placed on the installation surface as described above, the main surface 2 forms an angle with respect to the installation surface. Since the test kit attached to the color measurement tool 1 is approximately parallel to the main surface 2, the color development unit 102 also forms an angle with respect to the installation surface similar to that of the main surface 2. This makes it possible to prevent a situation in which the shadow of the imaging device is cast on part of the test kit when the subject takes an image.

[0031] As described above, the color measurement tool 1 according to this embodiment can effectively prevent the shadow of the test kit or the shadow of the imaging device from appearing in the image even when the subject himself / herself acquires an image of the test kit using a smartphone, etc. This significantly contributes to improving the accuracy of remote testing and also greatly contributes to the spread of remote testing.

[0032] Although not essential to the present invention, the color measurement tool 1 according to this embodiment is provided with two stoppers 41 in addition to the scaffolding 20. After the test kit 100 is attached to the color measurement tool 1, as shown in Fig. 4, when the stopper 41 is folded to the same side as the scaffolding 20, the test kit 100 inserted from the side into the recess hits the stopper 41 when attempting to slide within the recess after attachment. This makes it possible to suitably prevent the test kit 100 from sliding excessively and the color development portion 102 from departing from the range of the window.

[0033] In this embodiment, the angle that the main surface 2 makes with the installation surface Gr when the assembled color measurement tool 1 is placed on the installation surface Gr can be appropriately set by changing the shape of the scaffolding 20. The inventors' study has revealed that when the angle that the main surface makes with respect to the installation surface is set to 20° to 30°, it is most likely to prevent the shadow of the imaging device from appearing in the image, and when the angle exceeds 45°, it is difficult for the main surface to be illuminated by light from a lighting source or the like that is usually located above, resulting in a dark image, or the possibility that a shadow caused by a step between the upper surface and the color-developing portion of the test kit will fall on the color-developing portion increases slightly.

[0034] There is no particular limitation on the material of the color measurement tool 1, but it is preferable that the main surface 2 is made of paper, since this makes it easier to form the chart portion 30 by printing. More specifically, - The color must be white and have the same brightness as immunochromatographic test paper -Does not contain optical brighteners -Good printability - Not too smooth If the color measurement tool 1 is made entirely of paper, it must have enough rigidity to be able to hold the assembled tool in place for a certain period of time. The paper constituting the main surface 2 can be selected taking these factors into consideration.

[0035] The color measurement tool according to this embodiment can be applied to both qualitative testing, which mainly determines whether a line appears, and quantitative testing, which mainly determines the thickness of the line that appears. The following describes the configuration of the chart portion suitable for quantitative testing.

[0036] The chart unit 30A shown in FIG. 5 has a color chart 110 and a density chart 120, but does not include a brightness chart. Color chart 110 is generally similar to color chart 31, and is composed of six color panels of red R, blue B, green G, yellow Y, cyan C, and magenta M, as shown in FIG.

[0037] In the example shown in FIG. 5, the density chart 120 includes four charts, a black chart 121, a blue chart 122, a red chart 123, and a green chart 124, each of which is made up of six panels of the same color that differ only in density. The panel colors in the density chart need only include the same colors as the lines that appear in the color-exhibiting portion, and the minimum configuration is only one color that corresponds to the line that appears in the color-exhibiting portion. By including multiple color charts in the density chart 120, the versatility of the color measurement tool is increased, and it can be used with a variety of test kits. In quantitative testing, the density of the line that appears in the colored area changes depending on the amount of the substance to be detected, such as an antigen or antibody, so the number of panels and the concentration of each panel can be determined depending on the amount and stage of the substance to be detected.

[0038] In quantitative tests, where the test value changes based on the thickness of the line, the surrounding environment has a greater influence than in qualitative tests, where only the presence or absence of a line is judged. Specifically, in terms of brightness, in addition to the influence of shadows mentioned above, the thickness of the line may appear different if the entire area is too bright or too dark. Furthermore, if the overall color temperature, which is influenced by lighting, etc., becomes close to the color of the line that appears in the color-developing area, it may become difficult to correctly judge the thickness of the line. When the thickness of the line is ultimately judged by a human, these factors also affect the judgment.

[0039] An example of image correction using the chart unit 30A in a qualitative inspection will be described. First, a numerical value relating to the hue of the color chart 110 in the image including the acquired colored portion and the chart portion 30A is acquired, and a conversion parameter is created so that this corresponds to a theoretical value of the hue (Step A). ​​The density chart 120 may be used to create the conversion parameter. Next, the color tone of the entire image including the colored portion is corrected using the conversion parameters obtained in step A to create a corrected image suitable for quantitative evaluation (step B). In step B, if the thinnest panel of the density chart 120 cannot be detected in either the acquired image or the corrected image, it may be determined that the image is an error image that cannot be used for judgment. In this case, a message may be sent to the sender of the image to encourage re-imaging.

[0040] The determination of the colored portion in the image using the corrected image (step C) may be performed automatically by a machine or visually by a human. In either case, a highly accurate determination can be made by comparing the thickness of the lines appearing in the colored portion in the corrected image with the density chart 120. When step C is performed by a machine, if an error is determined in step B, a message such as "Patches up to the xth patch are not visible, so detection is not possible below x mAbs" may be displayed alone or together with the detected results. In step C, it is not necessary to determine that the line density of the colored portion is the same as that of any panel of the density chart 120. For example, the line density of the colored portion may be determined to be an intermediate density between the two panels.

[0041] The chart section 30A may have a brightness chart in addition to the color chart 110 and the density chart 120. When the density chart includes a black chart, as in the chart section 30A, the black chart can also be used as a brightness chart. The density chart is used to check the performance of the camera to see how well it can capture images. The brightness chart is used to recognize and correct deviations in the camera's gradation characteristics and gray balance. As described above, since step A can be performed using only the color chart, the chart section may be composed of only the color chart.

[0042] In the chart unit according to the present invention, the number and types of color panels in the color chart are not limited to the above-mentioned six types. As a minimum configuration, three colors, red, green, and blue, are sufficient, and other colors such as purple and orange may be added.

[0043] Although the present invention has been described above based on one embodiment, the specific configuration is not limited to this embodiment, and configuration changes and combinations within the scope of the gist of the present invention are also included. Some modifications are exemplified below, but these are not all inclusive, and other modifications are also possible. Two or more of these modifications may be appropriately combined.

[0044] The color measurement tool according to the present invention is not limited to being assembled from a single sheet-like member. For example, the scaffolding may be prepared as a separate member from the main surface, and may be attached to the member including the main surface by being inserted or engaged therewith. However, if the pre-assembled shape is a single sheet, the pre-assembled color measurement tool becomes easier to handle, can be easily mailed to the subject together with the test kit, and has the advantage of preventing the scaffolding parts, etc. from being lost.

[0045] The color measurement tool according to the present invention does not have to be entirely made of the same material. For example, the main surface may be made of paper, and a sheet of a different material may be attached to it to ensure rigidity, or only the scaffolding may be made of a material that is more rigid than paper, such as wood or metal.

[0046] The mechanism for attaching the test kit to the secondary side is not limited to the embodiment in which the test kit is sandwiched between the secondary side and the scaffolding. For example, a configuration in which a double-sided tape or adhesive is placed on the secondary side and the test kit is attached to the secondary side by sticking it thereto can also be adopted.

[0047] As shown in Fig. 3, the color measurement tool 1 according to the embodiment is provided with a two-dimensional code 40. Although the two-dimensional code is not essential for the color measurement tool according to the present invention, providing the two-dimensional code makes it possible to achieve the following, for example. Correction parameters (such as color chart conversion coefficients related to color conversion of the captured image) are set and saved according to the printing conditions (printing machine, ink lot, etc.) of the mass-produced color measurement tool 1. After that, the two-dimensional code is read from the received inspection image to obtain the saved correction parameters, and correction is performed using these parameters. This enables detailed correction according to the production lot of the color measurement tool and each individual color measurement tool. - The 2D code is read from the received inspection image, and a check is made to see if an image containing this color measurement tool has already been judged. By refusing to judge an image containing a color measurement tool that has already been judged once, it is possible to prevent the reuse or illegal diversion of color measurement tools. The two-dimensional code 40 is an example of the reading information, and other codes may be used. The reading information may be printed directly on the color measurement tool, or may be printed on a sticker or the like to be affixed to the color measurement tool.

[0048] In the color measurement tool according to the present invention, it is not essential that the test kit is held so as not to protrude on the main surface side. For example, if the test kit is thin or the angle of the scaffolding is suitable, and the shadow of the test kit does not need to be considered, the test kit may be placed on the main surface at an angle to the installation surface. Such a configuration can be realized, for example, by providing a stopper that protrudes from the main surface and prevents the test kit from slipping off. [Explanation of symbols]

[0049] 1 Color measurement tool 2 Main surface 20 Scaffolding 30, 30A Chart section 31, 110 Color Chart 32 Lightness Chart 100 Test Kits 102 Colored part 120 Concentration Chart

Claims

1. A color measurement tool for use with a test kit having a color development unit, A main surface; A scaffolding section configured to be able to hold the main surface at an angle with respect to an installation surface; a chart portion formed on the main surface and having a color chart; Equipped with When the test kit is attached, the color-changing portion is configured to be held so as to be visible from the main surface side. Color measurement fixture.

2. the chart unit further includes at least one of a density chart and a brightness chart; The color measurement tool according to claim 1 .

3. When the test kit is attached, the test kit is held so as not to protrude toward the main surface. The color measurement tool according to claim 1 .

4. The main surface is formed of paper, The chart portion is formed by printing. The color measurement tool according to claim 1 .

5. The scaffolding portion holds the main surface at an angle of 20° to 30° with respect to the installation surface. The color measurement tool according to claim 1 .

6. The scaffolding portion is connected to the main surface and formed as a single sheet as a whole, The scaffold portion is folded relative to the main surface, so that the main surface can be held at an angle relative to the installation surface. The color measurement tool according to claim 1 .

7. The test kit is held between the scaffold and the main surface. The color measurement tool according to claim 3 .

8. A test kit having a color development section is attached to the color measurement tool according to any one of claims 1 to 7, An image of the color measurement tool is captured from the main surface side in a state in which the main surface is at an angle with respect to the installation surface, to obtain an image including the color presentation portion and the chart portion; creating a corrected image by correcting the image of the colored portion in the image using information on the chart portion in the image; determining a state of the colored portion based on the corrected image; Color measurement method.

Images