Medical image-capturing instrument color chart, medical image color correction jig, and medical image color correction device set

Abstract

To provide a medical image-capturing instrument color chart that enables decreasing a color difference in medical image among the medical image-capturing instruments.SOLUTION: A medical image-capturing instrument color chart 10 has: a regular reflection suppression area 1 that suppresses a regular reflection of light from a light source; and a color patch area 2 that includes a plurality of color patches provided around the regular reflection suppression area. According to the medical image-capturing instrument color chart of the present disclosure, since the color patch area with the plurality of color patches is arranged around the regular reflection suppression area, the regular reflection of the light in a center, at which the light is prone to converge, of the color chart is suppressed, and difficulty reading the color patch can be suppressed, which in turn enable an accurate color correction of a medical image, and enable suppression of a difference in color reproducibility among the medical image-capturing instruments.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a color chart used in medical imaging equipment, a color correction tool for medical images, and a color correction device set for medical images. [Background technology]

[0002] In order to display an output image with correctly reproduced colors, an imaging device uses, for example, a color chart as disclosed in Patent Document 1 to compare the reproduced colors of the imaging device with those of the color chart, and if there is a difference in the reproduced colors, the imaging device is calibrated based on the color chart.

[0003] 2. Description of the Related Art Medical image display systems that capture images of the affected area of ​​a patient and display the images on a monitor screen are used in many medical settings. For example, medical imaging devices such as fundus examination machines and microscopes used in ophthalmology, ear scopes used in otolaryngology, and endoscope cameras each have their own unique color characteristics. For example, when the exact same subject is photographed with multiple cameras, the image data obtained may differ from each other. In addition, imaging devices often have a specific lighting device, and the images obtained may differ depending on the lighting environment in which the imaging device is used.

[0004] Telemedicine has been attracting attention as a way to eliminate disparities in medical care in remote areas. In addition, the spread of the novel coronavirus disease (COVID-19) has led to the recognition of the importance of telemedicine from the perspective of infection prevention. Even in telemedicine, if the color reproducibility of image data obtained by each imaging device differs, color recognition may not be performed correctly, which may affect accurate diagnoses by doctors. Therefore, it is preferable to suppress differences in color reproducibility between medical imaging devices. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2004 / 044639 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure has been made in consideration of the above problems, and has an object to provide a color chart for medical imaging devices and the like that can reduce color differences in medical images between medical imaging devices. [Means for solving the problem]

[0007] The present disclosure provides a color chart for use in medical imaging equipment, the color chart having a specular reflection suppression area that suppresses specular reflection of light from a light source, and a color patch area including a plurality of color patches arranged around the specular reflection suppression area.

[0008] The present disclosure also provides a color correction tool for medical images, which performs color correction on medical images obtained by medical imaging equipment, and which has a base on which the above-mentioned color chart for medical imaging equipment is arranged, and a side wall connected to the base and arranged to surround the color chart.

[0009] The present disclosure also provides a medical image color correction device set having the above-mentioned medical image color correction tool, and an imaging device and a light source arranged in a position facing the color chart. Effect of the Invention

[0010] The color chart for medical imaging equipment of the present disclosure has the effect of reducing color differences in medical images between medical imaging equipment. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic top view illustrating a color chart for medical imaging equipment of the present disclosure; [Diagram 2]1 is a schematic top view illustrating specular reflection suppression areas and color patch areas in a color chart for medical imaging equipment according to the present disclosure; [Diagram 3] 1 is a schematic cross-sectional view illustrating a color chart for medical imaging equipment according to the present disclosure. [Figure 4] This is an xy chromaticity diagram showing the results of analyzing the colors inside the outer ear and the color of the fundus. [Diagram 5] FIG. 2 is an xy chromaticity diagram showing in-the-outer-ear colors of the medical imaging equipment color chart of the present disclosure. [Figure 6] FIG. 2 is an xy chromaticity diagram showing fundus colors of the color chart for medical imaging equipment of the present disclosure. [Figure 7] 1A and 1B are a schematic cross-sectional view and a schematic perspective view illustrating a correction tool for performing color correction on an in-ear imaging device, respectively. [Figure 8] 1 is a schematic cross-sectional view illustrating a color correction apparatus set for color correction of an in-the-ear imaging device. [Figure 9] 1 is a schematic cross-sectional view illustrating a correction tool for performing color correction in a fundus imaging device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The following describes the embodiments of the present disclosure with reference to the drawings. However, the present disclosure can be implemented in many different forms, and should not be interpreted as being limited to the description of the embodiments exemplified below. In addition, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual form in order to make the explanation clearer, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each figure, elements similar to those described above with respect to the previous figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0013] In this specification, when describing a mode in which another component is disposed on a certain component, the term "above" or "below" is used, unless otherwise specified, to include both a case in which another component is disposed directly above or below a certain component so as to be in contact with the component, and a case in which another component is disposed above or below a certain component with another component interposed therebetween. Also, in this specification, when describing a mode in which another component is disposed on the surface of a certain component, the term "on the surface side" or "on the surface" is used, unless otherwise specified, to include both a case in which another component is disposed directly above or below a certain component so as to be in contact with the component, and a case in which another component is disposed above or below a certain component with another component interposed therebetween.

[0014] Medical imaging devices may use light sources with high linearity. For example, in recent years, ear scopes have been equipped with LEDs, and when a reflective color chart is photographed with an ear scope, specular reflection (regular reflection) occurs in front of the color chart, causing halation in the center of the color chart, making it impossible to obtain appropriate color information and making color correction difficult. In addition, non-mydriatic fundus cameras, which have been used in recent years, photograph the retina by shining a flash of light through the crystalline lens. The flash light used is very strong, and when a reflective color chart is photographed with a non-mydriatic fundus camera, halation occurs, making color correction difficult.

[0015] On the other hand, since these earscopes and non-mydriatic fundus cameras, etc., shine highly rectilinear light onto the area to be observed and capture the reflected light with a camera for use in diagnosis, it is desirable to use a reflective type color chart.

[0016] In order to solve the above problems, the inventors of the present disclosure conducted intensive research and found that by providing a specular reflection suppression region in the center of a color chart and providing a color patch region having a plurality of color patches around the specular reflection suppression region, the specular reflection of light from a light source is suppressed and accurate color correction is possible, thus completing the present invention. The color chart for medical imaging equipment of the present disclosure will be described below.

[0017] A. Color charts for medical imaging equipment FIG. 1 is a schematic top view illustrating a color chart for medical imaging equipment of the present disclosure. As shown in FIG. 1, a color chart 10 for medical imaging equipment of the present disclosure has a specular reflection suppression region 1 that suppresses specular reflection of light from a light source, and a color patch region 2 including a plurality of color patches provided around the specular reflection suppression region 1. As shown in FIG. 1, a color chart 10 for medical imaging equipment of the present disclosure may have an outer peripheral region 3 that is a region other than the specular reflection suppression region 1 and the color patch region 2. Furthermore, it may have a direction identification mark 4 that distinguishes the orientation of the specular reflection suppression region 1 and the color patch region 2. Furthermore, it may have a range identification mark 5 that indicates the range of the color chart 10.

[0018] According to the color chart for medical imaging devices of the present disclosure, a color patch region having a plurality of color patches is arranged around the specular reflection suppression region, so that specular reflection of light in the center of the color chart where light is likely to be collected is suppressed, and the difficulty in reading the color patches can be suppressed. Therefore, accurate color correction of medical images is possible, and the difference in color reproducibility between medical imaging devices can be suppressed.

[0019] 1. Specular reflection suppression area The specular reflection suppression region in the present disclosure is a region that suppresses specular reflection of light from a light source. The specular reflection suppression region does not usually include a color patch. Specifically, the specular reflectance of light with a wavelength of 360 nm to 740 nm in the specular reflection suppression region is preferably 5% or less, and more preferably 1% or less.

[0020] The specular reflectance of the specular reflection suppression region is a value obtained by subtracting the reflectance at de:8° from the reflectance at di:8°, measured under geometric condition c of JIS Z 8722: 2009, using light with a wavelength of 360 nm to 740 nm as incident light. The specular reflectance is the average value of measurements taken at any 10 points in the specular reflection suppression region.

[0021] The regular reflectance can be measured using a spectrophotometer, such as a CM-2500d spectrophotometer manufactured by Konica Minolta Japan, Inc.

[0022] The ratio of the area of ​​the specular reflection suppression region to the area of ​​the entire color chart may be, for example, 3% or more, or 33% or more. When the ratio of the area of ​​the specular reflection suppression region is in the above range, specular reflection of light from the light source can be sufficiently suppressed. On the other hand, it may be, for example, less than 100%, 80% or less, or 50% or less. When the ratio of the area of ​​the specular reflection suppression region is in the above range, the area of ​​the color patch region can be made large, and the accuracy of color correction is improved.

[0023] The total area of ​​the above color chart is 50 mm 2 It may be more than 70mm 2 It may be more than 500 mm. 2 It may be less than 400mm 2 It may be the following.

[0024] Furthermore, the ratio of the area of ​​the specular reflection suppression region to the total area of ​​the specular reflection suppression region and the color patch region described below is, for example, 3% or more, or may be 6% or more, or may be 25% or more. When the area ratio is equal to or more than the above value, reflection of light with high linearity by medical imaging equipment can be effectively suppressed, and the influence on reading of the color patch can be sufficiently reduced. On the other hand, it may be, for example, 50% or less. When the area ratio is equal to or less than the above value, an area in which the color patch can be arranged can be sufficiently secured within the limited area of ​​the entire color chart.

[0025] The shape of the specular reflection suppression region is not particularly limited, and examples thereof include a substantially rectangular shape and a substantially polygonal shape. Fig. 2 is a schematic top view illustrating the specular reflection suppression region and the color patch region in the color chart for medical imaging equipment of the present disclosure. Fig. 2(a) shows the specular reflection suppression region 1 having a substantially rectangular shape, Fig. 2(b) shows the specular reflection suppression region 1 having a substantially hexagonal shape, and Fig. 2(c) shows the specular reflection suppression region 1 having a substantially octagonal shape. Among these, the substantially rectangular shape and the substantially hexagonal shape are preferable from the viewpoint of increasing the area of ​​the specular reflection suppression region while ensuring the area of ​​the color patch region.

[0026] 2. Color patch area The color chart in the present disclosure has a color patch area including a plurality of color patches provided around a specular reflection suppression area 1. The color patch area is used for color calibration and includes a plurality of color patches of any color. As shown in Figs. 1 and 2, the color patch area 2 is preferably formed in contact with the outer periphery of the specular reflection suppression area 1. The color patch area preferably has a specular reflectance of 15% or less, more preferably 10% or less, for light with a wavelength of 360 nm to 740 nm. The method for measuring the specular reflectance of the color patch area is the same as the method for measuring the specular reflectance of the specular reflection suppression area.

[0027] The type of color patch can be appropriately selected depending on the color gamut (hereinafter sometimes simply abbreviated as "color gamut") that can be reproduced by the imaging device.

[0028] Here, the color gamut refers to a specific range in the visible region, and can be expressed, for example, as shown in FIG. 4, using an xy chromaticity diagram of the XYZ color system (CIE1931-XYZ color system) defined by the CIE (International Commission on Illumination). In the xy chromaticity diagram, the color gamut can be shown as a triangle in which the chromaticity coordinates of the vertices of R, G, and B are defined and connected by lines. Color gamuts have traditionally been defined by various color gamut standards, such as the sRGB standard and the NTSC standard. The sRGB standard is an international standard defined by the International Electrotechnical Commission (IEC). When calculating the coordinates of each color on the xy chromaticity diagram, known data of the D65 light source spectrum is used.

[0029] (1) Reference color patch The color patches may have color patches of a plurality of reference colors different from, for example, a common medical color, an inner ear color, and a fundus color, which will be described later. Examples of the reference colors include red, green, blue, cyan, magenta, and yellow. The colors of the color patches may include three colors of red (R), green (G), and blue (B), or three colors of cyan (C), magenta (M), and yellow (Y) as reference colors. For example, it is preferable to include three or more types including red, green, and blue, and it is preferable to include three or more types including cyan, magenta, and yellow, and it is even more preferable to include six or more types including red, green, blue, cyan, magenta, and yellow.

[0030] The coordinates of the reference colors on the xy chromaticity diagram are (0.735, 0.265), (0.627, 0.372) for red, and may be within the area surrounded by the curve portion of the blackbody locus BL where the color deviation is -0.01 between color temperatures of 1200 K or more and 6000 K or less and (0.520, 0.174). The blackbody locus is a locus on a chromaticity diagram that depicts the state of a completely black object as it changes with absolute temperature.

[0031] Green may be within the area surrounded by the curves of (0.005, 0.587), (0.014, 0.750), (0.074, 0.834), (0.155, 0.806), (0.345, 0.652), and the blackbody locus BL, where the color deviation is +0.02 between a color temperature of 6000 K or more and a color temperature of 7000 K or less.

[0032] Blue may be within the area surrounded by (0.174, 0.005), (0.131, 0.046), (0.073, 0.185), the straight line connecting the points where the color deviation is +0.02 and -0.01 at a color temperature of 15000 K on the blackbody locus BL, the curve portion where the color deviation is -0.01 at color temperatures from 15000 K to 7000 K on the blackbody locus BL, and (0.280, 0.054).

[0033] Cyan may be within the region surrounded by the curves of (0.073, 0.185), (0.005, 0.587), and the black body locus BL, where the color deviation is +0.02 between the color temperatures of 7000K or more and 15000K or less.

[0034] Magenta may be within the area surrounded by (0.520, 0.174), the black body locus BL curve with a color temperature of 7000K to 6000K and a color deviation of -0.01, and (0.280, 0.174).

[0035] Yellow may be within the area surrounded by (0.345, 0.652), the point on the black body locus BL where the color temperature is 6000K and the color deviation is +0.02, (0.512, 0.487).

[0036] (2) Achromatic color patch The color patches may include, for example, a plurality of achromatic patches having different brightness levels. The number of types of achromatic patches may be, for example, three or more, preferably five or more, and may be seven or more.

[0037] (3) Medical color patches The color patches include, for example, color patches of common medical colors. Here, Fig. 4(a) is an xy chromaticity diagram showing the results of analyzing the color inside the outer ear by acquiring the spectrum inside the outer ear with an endoscope and performing statistical processing, and the results of analyzing the color of the fundus from an image of a fundus camera. Fig. 4(b) is an xy chromaticity diagram showing the results of analyzing the color from an image of the liver taken by an endoscope (instrument 1 and instrument 2). From the results of Figures 4(a) and 4(b), it is presumed that the colors in the first region surrounded by the curve portion of the blackbody locus BL on the xy chromaticity diagram with a color deviation of 0.00 between color temperatures of 2000K to 3000K, the curve portion of the blackbody locus BL with a color deviation of -0.01 between color temperatures of 2000K to 3000K, the straight line connecting the points of color deviation of 0.00 and -0.01 at a color temperature of 2000K, and the straight line connecting the points of color deviation of 0.00 and -0.01 at a color temperature of 3000K are colors commonly found in living organisms. Therefore, it is preferable that a color chart used in medical imaging equipment includes color patches of such common medical colors regardless of the type of imaging subject.

[0038] (4) Color patches for use in the outer ear When the color chart of the present disclosure is used in an external ear imaging device such as an earscope, the color patch area includes, for example, a color patch of the first external ear color. Fig. 5 is an xy chromaticity diagram showing the result of acquiring the spectrum of the external ear with an endoscope and analyzing the color of the external ear by statistical processing. As shown in Fig. 5, the coordinate point of the first external ear color on the xy chromaticity diagram is preferably within a second region surrounded by a curved portion of the black body locus BL with a color deviation of -0.01 between a color temperature of 2000K or more and a color temperature of 6000K or less, a curved portion of the black body locus with a color deviation of 0.02 between a color temperature of 2000K or more and a color temperature of 6000K or less, a straight line connecting the points of the black body locus with a color deviation of -0.01 and a color deviation of 0.02 at a color temperature of 2000K, and a straight line connecting the points of the black body locus with a color deviation of -0.01 and a color deviation of 0.02 at a color temperature of 6000K. By including such a color patch of the first outer ear color, it is possible to perform color correction with high accuracy on the outer ear image. In Fig. 5, "x: earscope chart" indicates a preferred color patch color as a color chart for the earscope.

[0039] In this case, the color patch area preferably further includes the above-mentioned color patch of the second outer ear color. In this case, the coordinate point of the first outer ear color on the xy chromaticity diagram is preferably within a third region of ±0.05 in the x-axis direction and ±0.025 in the y-axis direction, centered on the reference point M (0.396, 0.388), and the coordinate point of the second outer ear color on the xy chromaticity diagram is preferably within a region other than the third region of the second region on the xy chromaticity diagram. Note that the reference M is a chromaticity obtained based on the spectral reflectance of melanin.

[0040] It is preferable that the color patch area further includes the above-mentioned color patch of the other outer ear color other than the first and second colors. In this case, the coordinate point of the other outer ear color on the xy chromaticity diagram may be in the third region or in the region other than the third region of the second region. The other outer ear colors may be three or more, four or more, or five or more.

[0041] (5) Color patches for the fundus When the color chart of the present disclosure is used in an imaging device such as a fundus camera used in ophthalmology, the color patch area includes, for example, a color patch of the first fundus color. Fig. 6 is an xy chromaticity diagram showing the result of analyzing the color of the fundus from an image of the fundus camera. It is preferable that the coordinate point of the first fundus color on the xy chromaticity diagram is within a fourth region surrounded by a curved portion of the blackbody locus BL with a color deviation of 0.00 between a color temperature of 1000K or more and a color temperature of 3000K or less, a curved portion of the blackbody locus BL with a color deviation of -0.01 between a color temperature of 1000K or more and a color temperature of 3000K or less, a straight line connecting the points of the blackbody locus BL with a color deviation of 0.00 and a color deviation of -0.01 at a color temperature of 1000K, and a straight line connecting the points of the blackbody locus BL with a color deviation of 0.00 and a color deviation of -0.01 at a color temperature of 3000K. By including such a color patch of the first fundus color, it is possible to perform color correction with high accuracy on the fundus image. In Fig. 6, "*: Fundus chart" indicates a color patch that is preferable as a color chart for a fundus camera.

[0042] In this case, it is preferable that the color patch area further includes a color patch of a second fundus color. In this case, the coordinate point of the first fundus color on the xy chromaticity diagram is in a fifth region surrounded by a curved portion of the blackbody locus BL with a color deviation of -0.01 between a color temperature of 1000K or more and a color temperature of 2400K or less, a curved portion of the blackbody locus with a color deviation of 0.00 between a color temperature of 1000K or more and a color temperature of 2400K or less, a straight line connecting a point of the blackbody locus with a color deviation of -0.01 and a point of the color deviation of 0.00 at a color temperature of 1000K, and a straight line connecting a point of the blackbody locus with a color deviation of -0.01 and a point of the color deviation of 0.00 at a color temperature of 2400K, and a coordinate point of the second fundus color on the xy chromaticity diagram is in a region other than the fifth region of the fourth region on the xy chromaticity diagram.

[0043] It is preferable that the color patch region further includes a color patch of a color for the fundus other than the first and second colors. In this case, the coordinate point of the color for the fundus on the xy chromaticity diagram may be in the fifth region or in a region of the fourth region other than the fifth region. The number of the colors for the fundus may be three or more, four or more, or five or more.

[0044] (6) Color patch The number of color patches in the color patch region is, for example, equal to or greater than 8, and preferably equal to or greater than 16. The greater the number of color patches, the more accurate the color correction can be. The size of each color patch on the color chart is 16 mm. 2 Less than 4mm is preferable 2 The following is particularly preferred. By having the size of the color patch in the above range, more color patches can be included in the color patch area. On the other hand, the size of each color patch is preferably 0.3 mm or less. 2 More than 0.5mm is preferable. 2 More preferably, 1 mm or more 2 The above is particularly preferable. When the size of the color patch is within the above range, the color information obtained from the color patch is less likely to be affected by surrounding color patches of other colors.

[0045] The shape of each color patch is not particularly limited and may be, for example, a rectangle, a circle, a polygon, etc. Figures 2(a) and 2(c) show that each color patch is substantially rectangular, and Figure 2(b) shows that each color patch is substantially hexagonal.

[0046] It is preferable that the difference in distance between the plurality of color patches and the specular reflection suppression region is small. The distance from the specular reflection suppression region refers to the distance of a straight line connecting the center of the specular reflection suppression region and the center of the color patch. In addition, the difference in distance is small, for example, the difference in distance between the color patch that is the farthest from the specular reflection suppression region and the color patch that is the shortest from the specular reflection suppression region is, for example, 1 mm or less, and may be 0.1 mm or less.

[0047] It is preferable that the multiple color patches are arranged around the specular reflection suppression region. This is because the difference in distance from the specular reflection suppression region is small. It is also preferable that the multiple color patches are arranged in random order. In this case, the color difference ΔE between adjacent color patches is preferably 3 or more, more preferably 4 or more, and particularly preferably 5 or more. If ΔE is 3 or more, the color patch is less likely to mix with adjacent colors when read, and erroneous detection is less likely to occur.

[0048] The color difference ΔE is ΔE={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2 It can be calculated from the CIELAB color coordinates using the CIE1976 color difference formula. The CIELAB color coordinates are expressed as L * a * b * It can be calculated by converting it into the color system using the following formula. L * =116f(Y / Y w )-16, a *=500[f(X / X w )-f(Y / Y w )], b * =200[f(Y / Y w )-f(Z / Z w )], t>(6 / 29) 3 If f(t)=t 1 / 3 t≦(6 / 29) 3 If f(t)=(1 / 3)*(29 / 6) 2 t+4 / 29 Where X w , Y w , Z w The X, Y, and Z values ​​are the coordinates of the white point.

[0049] The area of ​​the color patch region is not particularly limited, but may vary depending on the application. For example, the area may be 0.8 cm 2 More than 1.5cm 2 By having the area of ​​the color patch region in the above range, more color patches can be included in the color patch region. On the other hand, the area of ​​the color patch region may be, for example, 2.0 cm or more. 2 Less than 1.8cm 2 If the area of ​​the color patch region is within the above range, the specular reflection suppression region can be widened. Therefore, specular reflection of light from the light source can be further suppressed, and accurate color correction of medical images can be performed.

[0050] 3.Outer area The color chart of the present disclosure may have an outer peripheral region 3, which is a region other than the reflection suppression region 1 and the color patch region 2, as shown in FIG. 1. In the case of a color chart for an in-ear imaging device, the coordinate point of the color of the outer peripheral region on the xy chromaticity diagram may be within the third region, or may be within a region other than the third region of the second region. Similarly, in the case of a color chart for a fundus imaging device, the coordinate point of the color of the outer peripheral region on the xy chromaticity diagram may be within the fifth region, or may be within a region other than the fifth region of the fourth region.

[0051] By providing an outer peripheral region of such a color, it is possible to capture an image of the color chart under conditions similar to those when capturing an image of an actual subject.

[0052] 4. Mark 1, the color chart of the present disclosure may have a direction identification mark 4 for identifying the orientation of the specular reflection suppression region 1 and the color patch region 2. It may further have a range identification mark 5 indicating the range of the color chart 10. The shape and size of these marks are not particularly limited as long as they are large and recognizable as marks, and can be appropriately adjusted depending on the design of the color chart, etc.

[0053] 5.Specific structure The color chart in the present disclosure is not particularly limited in its specific structure as long as it has the specular reflection suppression region and the color patch region as described above. Figures 3(a) to 3(c) are schematic cross-sectional views illustrating examples of the color chart for medical imaging equipment of the present disclosure.

[0054] The color chart 10 shown in Fig. 3(a) has a base layer 11, a printed layer 12, and a specular reflection suppression layer 14 formed in the center of the surface of the printed layer 12 opposite the base layer 11. A low reflection film 13 may also be formed on the surface of the printed layer 12 opposite the base layer 11. In Fig. 3(a), the specular reflection suppression region 1 is, for example, a region having the base layer 11, the printed layer 12, and the specular reflection suppression layer 14. The color patch region 2 is, for example, a region having the base layer 11 and the printed layer 12.

[0055] (1) Specular reflection suppression layer The specular reflection suppression layer is not particularly limited as long as it has the function of suppressing the specular reflection of light from a light source, but a layer having a specular reflectance of light with a wavelength of 360 nm to 740 nm in the above range is preferable. The specular reflection suppression layer is, for example, a surface uneven layer having an uneven surface. Such a surface uneven layer has a microporous structure, and light enters the microporous structure and absorbs the light. An example of a layer having a microporous structure is FineShut SP from Koyo Orient Japan Co., Ltd. Also, an example of a layer having a light-shielding groove with a fine uneven structure and absorbing light from a direction perpendicular to the light-shielding groove. An example of a layer having such a fine light-shielding groove structure is FineShut Kyoku from Koyo Orient Japan Co., Ltd. The layer having a microporous structure and the layer having a fine light-shielding groove structure may each contain a foamed resin such as polyurethane foam and a dark-colored pigment such as carbon black or titanium black. Also, an example of a layer in which light enters and is absorbed inside the hair such as a flocked cloth or velvet.

[0056] The regular reflection suppressing layer may be, for example, a resin layer containing a dark color pigment such as carbon black or titanium black.

[0057] (2) Base material layer Examples of the substrate layer include paper substrates, resin substrates, nonwoven fabrics, etc. Specific examples of the paper substrate include matte paper, semi-gloss paper, plain paper, laminated paper, etc. Among them, the 60° specular gloss is preferably 10 or less, more preferably 8 or less. When the 60° specular gloss is in the above range, the regular reflectance in the color patch area and the regular reflection suppression area can be further suppressed. The 60° specular gloss of the substrate layer is the average value of the 60° specular gloss measured at any 10 points of the substrate layer according to Method 3 of JIS Z 8741. A gloss meter can be used as the measuring instrument. For example, GM-268A manufactured by Konica Minolta Japan, Inc. can be used as the gloss meter.

[0058] The regular reflectance of the base layer is preferably 1.25% or less, and more preferably 1.00% or less. The method for measuring the regular reflectance of the base layer is the same as the method for measuring the regular reflectance of the regular reflection suppression region.

[0059] When the base layer is paper, the basis weight is not particularly limited, but is preferably 50 g / m 2 More than 300g / m 2 The following is the result.

[0060] The thickness of the base layer is not particularly limited, but is preferably 20 μm or more and 1,000 μm or less, more preferably 30 μm or more and 500 μm or less, and even more preferably 50 μm or more and 200 μm or less.

[0061] (3) Printing layer The printed layer is a layer on which the above-mentioned multiple color patches are printed. The printed layer can be formed by a printing method such as gravure printing, inkjet printing, offset printing, flexographic printing, screen printing, etc. Alternatively, a substrate such as glass on which dyes corresponding to the colors of the color patches are fixed, or a substrate such as a plastic film on which pigments corresponding to the colors of the color patches are kneaded can be used.

[0062] (4)Low reflective coating The color chart of the present disclosure may have a low-reflection film on the side of the printing layer opposite to the substrate layer. By disposing the low-reflection film, the regular reflectance in the color patch area and the regular reflection suppression area can be further suppressed. An example of the low-reflection film is an anti-reflection film used as a surface layer of a monitor display, etc.

[0063] (5) Other structures The color chart 10 shown in FIG. 3(b) has a base layer 11 that is perforated at the center and is disposed on a base 21 that has a recess in the center, a printed layer 12, and a specular reflection suppression layer 14 that is formed in the recess of the base 21. The color chart 10 may also have a low-reflection film 13 that is formed on the surface of the printed layer 12 opposite to the base layer 11. As shown in FIG. 3(b), it is preferable that the surface of the specular reflection suppression region 1 is lower in height (position in the direction D1 perpendicular to the in-plane direction D2 of the color chart) than the surface of the color patch region 2. This is because light reflected by the specular reflection suppression region 1 can be suppressed from entering the color patch region.

[0064] The color chart 10 shown in FIG. 3(c) has a base layer 11, a cone- or pyramidal-shaped protrusion 15 arranged at the center of the base layer 11, and a printed layer 12 formed around the protrusion 15. In FIG. 3(c), the regular reflection suppression region 1 is, for example, a region having the base layer 11 and the protrusion 15. The color patch region 2 is, for example, a region having the base layer 11 and the printed layer 12. In addition, the printed layer 12 may have a low reflection film 13 on the surface opposite to the base layer 11. The protrusion 15 may have a light reflecting function or a light absorbing function.

[0065] 6. How to use the color chart The color chart of the present disclosure is used for color correction of medical images. First, the color chart is illuminated with a light source and photographed by an imaging device. At this time, the imaging device and the light source are arranged on the same side of the color chart. After photographing the color chart, an arithmetic circuit of the imaging device compares the color patches included in the color chart on the photographed image with reference color patches previously stored in a memory unit of the imaging device, and calculates the color correction amount of the imaging device based on the chromaticity of both. The correction amount is applied to a medical image photographed by the same imaging device, thereby performing color correction of the medical image. Such color correction may be performed using only one of the color patches, or may be performed using multiple color patches.

[0066] B. Color correction tool for medical images The present disclosure provides a medical image color correction tool for performing color correction on a medical image obtained by a medical imaging device, the medical image color correction tool having a base on which the above-mentioned medical imaging device color chart is arranged, and a side wall connected to the base and arranged to surround the color chart. With such a medical image color correction tool having a side wall, it is possible to photograph the color chart in an environment similar to the inside of the body. By photographing in an environment similar to the inside of the body, it is not necessary to photograph the color chart and the affected area at the same time.

[0067] 1. Color correction tool for images inside the outer ear FIG. 7(a) is a schematic cross-sectional view illustrating a correction tool for performing color correction of an image obtained by an external ear imaging device. FIG. 7(b) is a schematic perspective view illustrating a base in the correction tool of the external ear imaging device. As shown in FIG. 7(a), the color correction tool 80A of the external ear imaging device has a base 50A on which the above-mentioned color chart 10 for medical imaging device is arranged, and a side wall 60A connected to the base 50A and arranged so as to surround the color chart. The side wall 60A has an inner wall 61 connectable to the base 50A and an outer wall 62 connectable to the inner wall 61. The inner wall 61 is preferably cylindrical, extending in a direction D1 perpendicular to the in-plane direction D2 of the color chart, and simulating the ear canal. Furthermore, at least the inner surface is preferably a flesh color close to the ear canal. The length L61 of the inner wall 61 is, for example, 30 mm or more, and may be 35 mm or more. The outer wall 62 preferably has a cylindrical shape that allows the insertion of the imaging device C. The outer wall 62 preferably has at least an outer surface that is light-shielding to block light from the outside. With such a correction tool, it is possible to take images in an environment similar to that in the outer ear.

[0068] The correction jig 80A of the in-ear imaging device preferably has a base 21 on which a color chart 10 is arranged. As shown in FIG. 7(b), the base 21 is, for example, in the shape of a container having a bottom 22 and a wall 23, and has a recess in the center of the bottom 22, a first bottom surface 22a which is the bottom surface of the recess, and a second bottom surface 22b which is located higher in the D1 direction than the first bottom surface. It is preferable that the specular reflection suppression layer 14 corresponding to the specular reflection suppression region is arranged on the first bottom surface 22a, and the printed layer 12 corresponding to the color patch region is arranged on the second bottom surface 22b. The depth H of the recess of the base 21 is, for example, 5 mm or more, and may be 1 cm or more.

[0069] Fig. 8 is a schematic cross-sectional view illustrating a correction device set for an external ear imaging device. As shown in Fig. 8, the correction device set 100 for an external ear imaging device includes a correction jig 80A, and an imaging device C and a light source that are arranged in a position facing the color chart 10 arranged on the correction jig 80A. The imaging device C in Fig. 8 is an earscope equipped with a light source.

[0070] In the in-ear imaging device correction apparatus set 100, the distance L10 between the imaging device C and the color chart 10 is, for example, 10 mm or more, and may be 15 mm or more, while it is, for example, 20 mm or less.

[0071] 2. Correction tool for color correction of fundus images FIG. 9 is a schematic cross-sectional view illustrating a correction jig for performing color correction of a fundus image obtained by a fundus imaging device. As shown in FIG. 9, a correction jig 80B of a fundus imaging device is integrated with a base 50B on which the above-mentioned color chart 10 for medical imaging device is arranged and a side wall 60B arranged so as to surround the color chart. The side wall 60B has a curved surface corresponding to the shape of an eyeball. For example, a commercially available dummy eye for practicing surgery on the retina, vitreous body, etc. can be used as such a correction jig 80B. In this case, the base 50B corresponds to the retina part. Furthermore, the correction jig 80B preferably has a lens 91 arranged at a position facing the color chart 10 and an ND filter 90 arranged between the lens 91 and the color chart 10. With such a correction jig, the color chart can be photographed in an environment similar to the environment in which the fundus is photographed.

[0072] In the human eye, the crystalline lens has a diameter of about 9 mm, and the diameter of the pupil varies from about 2 mm to 6 mm. The lens 91 is preferably sized to imitate the crystalline lens, and is preferably about 9 mm in diameter, for example. The area through which light passes is 28.26 mm when the pupil diameter is 6 mm during an actual fundus examination. 2 (3mm x 3mm x 3.14), whereas the simulated eye is 63.59mm 2 (4.5mm x 4.5mm x 3.14). The transmittance of the vitreous body is about 70%. Therefore, it is preferable to reduce the amount of incident light, and when using the above-mentioned artificial eye, it is preferable to reduce the incident light to 30% or less. Therefore, it is preferable to place an ND filter 90 on the correction jig 80B. Furthermore, by placing the ND filter 90 between the lens 91 and the color chart 10, an anti-reflection film is not required.

[0073] C. Medical image color correction device set The present disclosure provides a medical image color correction device set having the above-mentioned medical image color correction tool, and an imaging device and a light source arranged in a position facing the color chart. The color correction tool for medical images is the same as that described in "B. Color correction tool for medical images". Examples of the imaging device include a fundus examination machine, a microscope, an earscope, and an endoscope camera. Examples of the imaging element of the imaging device include a charge-coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS). The light source varies depending on the type of imaging device, and may be built into the imaging device or may be disposed separately from the imaging device.

[0074] D.Other The present disclosure provides a color chart for medical imaging equipment, the color chart having a color patch area including a plurality of color patches, the color patch area including the color patches of common medical colors, and the coordinate points on the xy chromaticity diagram of the common medical colors are within a first area surrounded by a curve portion of the blackbody locus BL with a color deviation of 0.00 between color temperatures of 2000K and 3000K inclusive, a curve portion of the blackbody locus BL with a color deviation of -0.01 between color temperatures of 2000K and 3000K inclusive, a straight line connecting the points of color deviation of 0.00 and -0.01 at a color temperature of 2000K, and a straight line connecting the points of color deviation of 0.00 and -0.01 at a color temperature of 3000K.

[0075] The present disclosure provides a color chart for medical imaging equipment, the color chart having a color patch area including a plurality of color patches, the color patch area including the color patch of a first outer ear internal color, the coordinate point of the first outer ear internal color on the xy chromaticity diagram being within a second area surrounded by a curve portion of the blackbody locus BL of a color deviation of -0.01 between a color temperature of 2000K or more and a color temperature of 6000K or less, a curve portion of the blackbody locus of a color deviation of 0.02 between a color temperature of 2000K or more and a color temperature of 6000K or less, a straight line connecting the point of the blackbody locus of a color deviation of -0.01 and the point of a color deviation of 0.02 at a color temperature of 2000K and a straight line connecting the point of the blackbody locus of a color deviation of -0.01 and the point of a color deviation of 0.02 at a color temperature of 6000K.

[0076] The present disclosure provides a color chart for medical imaging equipment, the color chart having a color patch area including a plurality of color patches, the color patch area including the color patch of a first fundus color, the coordinate point of the first fundus color on the xy chromaticity diagram being within a fourth region surrounded by a curve portion of the blackbody locus BL with a color deviation of 0.00 between a color temperature of 1000 K or more and a color temperature of 3000 K or less, a curve portion of the blackbody locus BL with a color deviation of -0.01 between a color temperature of 1000 K or more and a color temperature of 3000 K or less, a straight line connecting the point of the color deviation of 0.00 and the point of the color deviation of -0.01 on the blackbody locus BL at a color temperature of 1000 K, and a straight line connecting the point of the color deviation of 0.00 and the point of the color deviation of -0.01 on the blackbody locus BL at a color temperature of 3000 K.

[0077] The present invention is not limited to the above-mentioned embodiment. The above-mentioned embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention.

[0078] Thus, in the present disclosure, for example, the following inventions are provided:

[0079] [1] A color chart for use in medical imaging equipment, comprising: a specular reflection suppression area that suppresses specular reflection of light from the light source; A color patch area including a plurality of color patches and arranged around the specular reflection suppression area.

[0080] [2] The color chart for medical imaging equipment according to [1], wherein the specular reflection suppression region has a specular reflectance of 5% or less for light with a wavelength of 360 nm to 740 nm.

[0081] [3] The color chart for medical imaging equipment according to [1] or [2], wherein the color patch area has a regular reflectance of 15% or less for light with a wavelength of 360 nm to 740 nm.

[0082] [4] The color chart for medical imaging equipment described in any of [1] to [3], wherein the colors of the multiple color patches include three colors of red (R), green (G) and blue (B), or three colors of yellow (Y), cyan (C) and magenta (M) as reference colors.

[0083] [5] The color chart for medical imaging equipment according to any one of [1] to [4], wherein the color patch area has a plurality of achromatic color patches.

[0084] [6] The color patch area includes color patches of common medical colors, A color chart for medical imaging equipment described in any of [1] to [5], wherein the coordinate points on the xy chromaticity diagram of the common medical colors are within a first region surrounded by a curve portion of the blackbody locus where the color deviation is 0.00 for a color temperature of 2000K or more and 3000K or less, a curve portion of the blackbody locus where the color deviation is -0.01 for a color temperature of 2000K or more and 3000K or less, a straight line connecting the point of color deviation 0.00 and the point of color deviation -0.01 for a color temperature of 2000K, and a straight line connecting the point of color deviation 0.00 and the point of color deviation -0.01 for a color temperature of 3000K.

[0085] [7] the color patch area includes the color patch of a first in-outer ear color; The color chart for medical imaging equipment described in any of [1] to [6], wherein the coordinate point on the xy chromaticity diagram of the first color for use inside the outer ear is within a second region surrounded by a curve portion of the blackbody locus with a color deviation of -0.01 for a color temperature of 2000 K or more and a color temperature of 6000 K or less, a curve portion of the blackbody locus with a color deviation of 0.02 for a color temperature of 2000 K or more and a color temperature of 6000 K or less, a straight line connecting the point of color deviation of -0.01 and the point of color deviation of 0.02 on the blackbody locus at a color temperature of 2000 K, and a straight line connecting the point of color deviation of -0.01 and the point of color deviation of 0.02 on the blackbody locus at a color temperature of 6000 K.

[0086] [8] The color patch area further includes a color patch of a second outer ear color; a coordinate point on the xy chromaticity diagram of the first color for inner ear is in a third region having a center at (0.396, 0.388) and a range of ±0.05 in the x-axis direction and ±0.025 in the y-axis direction; A color chart for medical imaging equipment as described in [7], wherein the coordinate point on the xy chromaticity diagram of the second color for use inside the outer ear is within an area of ​​the second area on the xy chromaticity diagram other than the third area.

[0087] [9] the color patch area includes the color patch of a first fundus color; The coordinate point of the first fundus color on the xy chromaticity diagram is within a fourth region surrounded by a curve portion of the blackbody locus with a color deviation of 0.00 between a color temperature of 1000 K or more and a color temperature of 3000 K or less, a curve portion of the blackbody locus with a color deviation of -0.01 between a color temperature of 1000 K or more and a color temperature of 3000 K or less, a straight line connecting the point of color deviation of 0.00 and the point of color deviation of -0.01 on the blackbody locus with a color temperature of 1000 K, and a straight line connecting the point of color deviation of 0.00 and the point of color deviation of -0.01 on the blackbody locus with a color temperature of 3000 K. A color chart for medical imaging equipment described in any of [1] to [8].

[0088]

[10] The color patch area further includes the color patch of a second fundus color, the coordinate point of the first fundus color on the xy chromaticity diagram is within a fifth region surrounded by a curve portion of the blackbody locus of color deviation -0.01 between a color temperature of 1000K or more and a color temperature of 2400K or less, a curve portion of the blackbody locus of color deviation 0.00 between a color temperature of 1000K or more and a color temperature of 2400K or less, a straight line connecting the point of color deviation -0.01 and the point of color deviation 0.00 on the blackbody locus of color temperature 1000K, and a straight line connecting the point of color deviation -0.01 and the point of color deviation 0.00 on the blackbody locus of color temperature 2400K, The color chart for medical imaging equipment described in [9], wherein the coordinate point on the xy chromaticity diagram of the second fundus color is within a region other than the fifth region of the fourth region on the xy chromaticity diagram.

[0089]

[11] A tool for color correction of medical images obtained by a medical imaging device, A color correction tool for medical images, comprising: a base on which a color chart for medical imaging equipment described in any one of [1] to

[10] is arranged; and a side wall connected to the base and arranged to surround the color chart.

[0090]

[12] The color correction tool for medical images is a tool for performing color correction of an image inside the outer ear, The base has a recess in the center, a first bottom surface which is a bottom surface of the recess, and a second bottom surface which is located higher than the first bottom surface, a specular reflection suppression layer corresponding to the specular reflection suppression region is disposed on the first bottom surface; A color correction tool for medical images as described in

[11] , wherein a printing layer corresponding to the color patch area is arranged on the second bottom surface.

[0091]

[13] The medical image color correction tool is a tool for performing color correction of a fundus image, The base and the side wall are integral with each other, The side wall is a curved surface corresponding to the shape of an eyeball, a lens disposed in a position facing the color chart; The color correction tool for medical images described in

[11] , further comprising an ND filter disposed between the lens and the color chart.

[0092]

[14] A color correction tool for medical images described in any one of

[11] to

[13] , wherein the side wall has a light-blocking property.

[0093]

[15]

[11] to

[14] , and a color correction tool for medical images according to any one of the above. and an imaging device and a light source disposed opposite the color chart. [Explanation of symbols]

[0094] 1 … Specular reflection suppression area 2 … Color patch area 3 … Outer area 10…Color chart 80... Color correction tool for medical images 100... Medical image color correction device set

Claims

1. A color chart for use in medical imaging equipment, comprising: a specular reflection suppression area that suppresses specular reflection of light from the light source; a color patch area including a plurality of color patches and arranged around the specular reflection suppression area.

2. 2. The color chart for medical imaging equipment according to claim 1, wherein the specular reflection suppression area has a specular reflectance of 5% or less for light with a wavelength of 360 nm to 740 nm.

3. 2. The color chart for medical imaging equipment according to claim 1, wherein the color patch area has a regular reflectance of 15% or less for light with a wavelength of 360 nm to 740 nm.

4. 2. The color chart for medical imaging equipment according to claim 1, wherein the colors of the plurality of color patches include three colors of red (R), green (G) and blue (B) or three colors of yellow (Y), cyan (C) and magenta (M) as reference colors.

5. The color chart for medical imaging equipment according to claim 1 , wherein the color patch area has a plurality of achromatic color patches.

6. The color patch area includes color patches of common medical colors, 2. The color chart for medical imaging equipment according to claim 1, wherein the coordinate points on the xy chromaticity diagram of the common medical colors are within a first region surrounded by a curve portion of the blackbody locus with a color deviation of 0.00 for a color temperature of 2000 K or more and 3000 K or less, a curve portion of the blackbody locus with a color deviation of -0.01 for a color temperature of 2000 K or more and 3000 K or less, a straight line connecting the points of color deviation of 0.00 and color deviation of -0.01 at a color temperature of 2000 K, and a straight line connecting the points of color deviation of 0.00 and color deviation of -0.01 at a color temperature of 3000 K.

7. the color patch area includes the color patch of a first in-outer ear color; 2. The color chart for medical imaging equipment according to claim 1, wherein the coordinate point on the xy chromaticity diagram of the first inner-outer-ear color is within a second region surrounded by a curve portion of the blackbody locus with a color deviation of -0.01 between a color temperature of 2000 K or more and a color temperature of 6000 K or less, a curve portion of the blackbody locus with a color deviation of 0.02 between a color temperature of 2000 K or more and a color temperature of 6000 K or less, a straight line connecting the point of the blackbody locus with a color deviation of -0.01 and the point of the color deviation of 0.02 at a color temperature of 2000 K, and a straight line connecting the point of the blackbody locus with a color deviation of -0.01 and the point of the color deviation of 0.02 at a color temperature of 6000 K.

8. The color patch area further includes a color patch of a second outer ear color; a coordinate point of the first inner-outer-ear color on the xy chromaticity diagram is in a third region having a center at (0.396, 0.388) and a range of ±0.05 in the x-axis direction and ±0.025 in the y-axis direction; 8. The color chart for medical imaging equipment of claim 7, wherein the coordinate point on the xy chromaticity diagram of the second inner-external-ear color is within a region of the second region on the xy chromaticity diagram other than the third region.

9. the color patch area includes the color patch of a first fundus color; 2. The color chart for medical imaging equipment according to claim 1, wherein the coordinate point of the first fundus color on the xy chromaticity diagram is within a fourth region surrounded by a curve portion of the blackbody locus with a color deviation of 0.00 between a color temperature of 1000 K or more and a color temperature of 3000 K or less, a curve portion of the blackbody locus with a color deviation of -0.01 between a color temperature of 1000 K or more and a color temperature of 3000 K or less, a straight line connecting the point of the blackbody locus with a color deviation of 0.00 and the point of the color deviation of -0.01 at a color temperature of 1000 K, and a straight line connecting the point of the blackbody locus with a color deviation of 0.00 and the point of the color deviation of -0.01 at a color temperature of 3000 K.

10. The color patch area further includes the color patch of a second fundus color, a coordinate point of the first fundus color on the xy chromaticity diagram is within a fifth region surrounded by a curve portion of the blackbody locus with a color deviation of -0.01 between a color temperature of 1000K or more and a color temperature of 2400K or less, a curve portion of the blackbody locus with a color deviation of 0.00 between a color temperature of 1000K or more and a color temperature of 2400K or less, a straight line connecting the point of the color deviation of -0.01 and the point of the color deviation of 0.00 at a color temperature of 1000K on the blackbody locus, and a straight line connecting the point of the color deviation of -0.01 and the point of the color deviation of 0.00 at a color temperature of 2400K on the blackbody locus, 10. The color chart for medical imaging equipment according to claim 9, wherein a coordinate point of the second fundus color on the xy chromaticity diagram is within a region of the fourth region on the xy chromaticity diagram other than the fifth region.

11. A tool for color correction of medical images obtained by a medical imaging device, comprising: A color correction tool for medical images, comprising: a base on which a color chart for medical imaging equipment according to any one of claims 1 to 10 is arranged; and a side wall connected to the base and arranged to surround the color chart.

12. The color correction tool for medical images is a tool for performing color correction of an image inside the outer ear, the base has a recess in the center, a first bottom surface which is a bottom surface of the recess, and a second bottom surface which is located higher than the first bottom surface; a specular reflection suppression layer corresponding to the specular reflection suppression region is disposed on the first bottom surface; The color correction tool for medical images according to claim 11 , wherein a printing layer corresponding to the color patch area is disposed on the second bottom surface.

13. The medical image color correction tool is a tool for performing color correction of a fundus image, the base and the sidewall are integral, The side wall is a curved surface corresponding to the shape of an eyeball, a lens disposed in a position facing the color chart; 12. The medical image color correction tool according to claim 11, further comprising an ND filter disposed between the lens and the color chart.

14. The medical image color correction tool according to claim 11 , wherein the side wall has a light-shielding property.

15. A color correction tool for medical images according to any one of claims 11 to 14, an imaging device and a light source disposed opposite the color chart;

Images