JP6499823B2 - Skin condition discrimination method based on fibrous structure analysis - Google Patents

Description

  The present invention relates to a method for discriminating skin conditions based on analysis of the fibrous structure of skin.

In order to or subjected to a beautifully kept or makeup of the skin, or to consider ways of skin care and make-up, the time or select the cosmetics, skin surface and the interior of the state, for example Hari elasticity of the skin, skin color, It is important to accurately grasp the state of talmi, stratum corneum, aging degree, texture, wrinkles, pores, and the like.
So far, a technique for discriminating wrinkles and textures using information obtained by performing image processing on a replica image or an enlarged photograph of the skin obtained as an evaluation material has been disclosed (Patent Literature). 1, 2).
In addition, a method has been developed in which skin is directly measured, its internal structure information is obtained, and the skin state is differentiated. In particular, a method for distinguishing the skin state based on an image obtained by a confocal laser microscope that enables non-invasive observation of a thick biological sample has attracted attention (Patent Documents 3 and 4). .

By the way, the dermis that functions as a support for the skin structure and plays a mechanical role is a tissue composed of 90% or more of collagen fibers and several% of elastin fibers. In the dermis, these fiber proteins exist as bundled fiber aggregates, and are entangled in almost all layers of the dermis to form a fibrous structure like a mesh. In general, the dermis layer becomes thinner and looser with aging, which is thought to be due to the decrease in the fiber protein. Collagen fibers and elastin fibers are also damaged by light such as ultraviolet rays (photoaging), and their abundance decreases, and they also change qualitatively, such as rupture and collapse of aggregates.
These fibrous proteins, quantifying the dermal collagen abundance using believed to may given a great influence on elasticity and wrinkle formation of skin, the near infrared absorption spectrum of skin for wrinkles progress prediction A method is known (Patent Document 5). Conversely, a method for estimating the internal structure of the skin such as the isotropy of collagen-like structures and the thickness of fibers using skin surface information such as texture and skin color as an index is also disclosed (Patent Document 6).

JP 2004-230117 A JP 2008-61892 A JP 2004-337317 A JP 2004-97436 A Japanese Patent Laying-Open No. 2005-083901 JP 2011-101738 A

However, the detailed examination of the correlation between the fibrous structure information and the skin condition has not been sufficiently conducted at present, and when the fibrous structure information is used as an index, what is the skin and how There has been no known differentiation method using quantitative estimation of the state of the disease.
An object of this invention is to provide the discrimination method of a skin state which can estimate a skin state with high precision simply and highly accurately and non-invasively in view of this situation.

As a result of intensive studies to solve the above problems, the present inventors have found that when the fibrous structure in the dermis is clearly present or the degree of disposition of the fibers is not high, It has been found that there is a correlation that the state of skin is poor when the condition is good and the fibrous structure is unclear or when the fibers are oriented even though they are clearly present. Then, the skin state is estimated using the fibrous structure information as an index, and it has been found that the quality of the skin state can be distinguished based on the estimation result, and the present invention has been completed.
Note that the present invention focuses on fibrous proteins including not only collagen fibers but also elastin fibers and the like, and uses the fibrous structure as a judgment material instead of the presence or absence or mere amount of the present invention. Is the first time.

That is, the present invention is as follows.
[1] A skin condition discrimination method characterized by estimating skin condition using fibrous structure information as an index. [2] The discrimination method according to [1], wherein the fibrous structure information is represented by one or more kinds of fibrous structure feature values selected from definition, directionality, and thickness.
[3] The discrimination method according to [2], wherein the fibrous structure feature is measured using a confocal laser microscope.
[4] The discrimination method according to [2], wherein the fibrous structure feature amount is estimated based on skin surface information.
[5] The discrimination method according to any one of [1] to [4], wherein the skin condition is one or more selected from elasticity / elasticity, talmi, skin color, texture, and pores.
[6] The discrimination method according to any one of [1] to [5], wherein the skin state is estimated using an estimation formula obtained by multivariate analysis.

  According to the present invention, there is provided a method for distinguishing a skin state quantitatively and non-invasively easily and with high accuracy. Thereby, useful information can be obtained when examining, selecting, and determining skin care and makeup methods tailored to individuals, and the information can be used for counseling regarding skin care and makeup methods.

It is a photograph which shows the fibrous structure which was image | photographed with the confocal laser microscope and which has various degrees of definition. It is a photograph which shows the fibrous structure which is image | photographed with the confocal laser microscope and which has various directions. It is a figure which shows the example of an analysis of the directionality of the fibrous structure by a cross binarization and a short straight line matching method. It is a graph showing the correlation between definition (measured value) and skin viscoelastic properties. It is a graph showing the correlation between definition (measured value) and skin color. It is a graph showing the correlation between the actual value of the sharpness and the estimated value. It is a graph showing the correlation between definition (estimated value) and skin viscoelastic properties. It is a graph showing the correlation between definition (estimated value) and skin color.

The skin condition discrimination method of the present invention is characterized in that the skin condition is estimated using the fibrous structure information as an index.
In the present specification, the fibrous structure refers to a network structure formed by a fiber aggregate in which fibrous proteins such as collagen and elastin are bundled in the dermis.
In the present specification, the fibrous structure information is represented by fibrous structure feature quantities such as definition, directionality, and thickness that characterize the state and arrangement of the fibrous structure. In the discrimination method of the present invention, one or more of the fibrous structure feature values are usually used as an index.

In the present invention, the method for acquiring the fibrous structure feature amount is not particularly limited, and the fibrous structure feature amount may be measured by actually observing the fibrous structure invasively or non-invasively, Or the value which estimated the fibrous structure feature-value by the estimation formula may be used for this invention.
As a method of actually observing the fibrous structure, for example, there is a method of measuring parameters using a confocal laser microscope. Since the confocal laser microscope can observe an image of a portion having the same depth with respect to an object, it can calculate a fibrous structure feature amount from a contour image (horizontal cross-sectional image) of the obtained fibrous structure. . In addition, it is useful because non-invasive observation can be performed on biomaterials in vivo. As the confocal laser microscope, those commercially available from Olympus and Lucid can be used without particular limitation.

Examples of the method for estimating the fibrous structure feature amount include a method for estimating based on skin surface information. The skin surface information includes, for example, skin unevenness, skin color, and the like, and the fibrous structure feature amount can be estimated by an estimation formula expressed using the skin unevenness parameter, skin color parameter, etc. that characterize these (special features). Open 2011-101738). The skin unevenness parameter is obtained by using, for example, an epidermis tissue quantification method (see Japanese Patent Application Laid-Open No. 2008-061892), a skin groove area, a skin groove average thickness, a skin groove thickness variation, a skin groove average interval, Examples include the parallelism of the skin groove, the degree of distortion (90 to 180 °), the mode number of the skin groove thickness, and the total number of connections. Skin color parameters include color systems such as RGB, Munsell (lightness, hue, saturation), L * a * b, XYZ, L * C * h, and Hunter Lab.
Note that when the fibrous structure feature amount estimated based on the skin surface information is used in the discrimination method of the present invention, the estimated skin state is usually different from the skin surface information used for estimation of the fibrous structure feature amount. Specifically, for example, when the fibrous structure feature amount estimated using the skin unevenness parameter is used in the discrimination method of the present invention, the skin state other than the unevenness of the skin (described later, elasticity / elasticity, tarmi, skin color, Estimate pores, etc.).

Hereinafter, the fibrous structure feature amount will be described.
The definition of the fibrous structure is the degree of contrast with the part where the fibrous structure is not detected when the fibrous structure of the dermis is imaged under the same conditions. What has been applied can be applied to the present invention. This difference in value is caused by the state of the fibrous protein, that is, the amount of the fibrous structure, the maturity of the fiber bundle, etc. The large degree of the contrast means that the fibrous structure is clearly present Indicates.
Referring to FIG. 1, when the skin condition is good, the fibrous structure has high definition and the network structure is clearly recognized (FIG. 1 a), but collagen fibers collapse due to aging and various damages When the fibrous structure changes due to the occurrence of solar elastosis or the like, the transition gradually changes from FIG. For example, FIG. 1abc, particularly FIG. 1ab is a preferable state.

An example of the sharpness measurement method will be described.
The “specific depth plane” selected on the basis of the measurement site of the measurement subject is imaged with a confocal laser microscope, and the resulting image scored visually can be used as the sharpness or obtained. A fast Fourier transform (FFT) analysis is performed on the density of the image in the obtained image, and the average intensity of an arbitrary cycle can be defined as the sharpness. In addition, the ranking when the average values are rearranged among all measurement subjects can be used as an index used in the present invention as a relative score of definition. A good score value or a large FFT analysis value indicates that the degree of contrast described above is large, that is, the fibrous structure is clearly present. For example, when the FFT analysis is performed on each image of FIG. 1, the average value of the analysis intensity in 20 to 50 cycles is 3.0 in FIG. 1abc representing a preferable skin state and larger in FIG. 1ab representing a more preferable state. The value is 3.1.

The directionality of the fibrous structure is such that the directions of the fiber bundles forming the fibrous structure are aligned.
Hereinafter, although it demonstrates with reference to FIG. 2, the red arrow in a figure represents the direction of a fiber bundle. When the skin condition is good, the fiber bundles are oriented in various directions and have a high anisotropy pattern (Fig. 2a). However, as the fibrous structure changes due to aging and various damages, it gradually becomes as shown in Fig. 2b → c. Thus, the fiber bundles are aligned in the same direction, and eventually the fiber bundles become isotropic, indicating deterioration of the skin condition (FIG. 2 d ).

An example of the directionality measurement method will be described.
For example, the directionality score can be acquired by image processing including cross binarization processing and short straight line matching processing described in Japanese Patent Application Laid-Open No. 2008-061892 and International Publication No. 2009/142069. First, in the captured image (FIG. 3a), the background and the object (fibrous structure) are separated by binarization processing, and the object is extracted as a shape. Accordingly, a highly accurate binarized image can be obtained from the entire screen from a thick and clear fibrous structure to a fine fibrous structure without unevenness (FIG. 3b). Next, the physical quantity of the object shape in the binarized image is calculated by the short straight line matching method. Specifically, a target short line (width: one pixel, several tens to several tens of pixels) composed of a plurality of pixels is applied to the target shape, and the connection between the start point and the end point of the short line is repeated. By covering with a short straight line, a short straight line matching image of a fibrous structure having various directions can be obtained (FIG. 3c). The number and angle of all the fitted short lines are measured, the physical quantity of the fibrous structure, for example, the parallelism is obtained, and the directionality score is calculated. For example, the number of short straight lines for each angle is counted, and the standard deviation between the angles with respect to the number represents parallelism, which can be used as an indicator of directionality. In addition, the ranking when the standard deviations are rearranged among all measurement subjects can be used as an index used in the present invention as a relative direction score. When the direction of the fibrous structure is present and its degree is high, that is, when the isotropic property is high, the short straight line is concentrated at a certain angle, so the standard deviation is small, and when the parallelism is low, that is, when the anisotropy is high Has a large standard deviation because the short straight lines are dispersed in various directions.
The skin when the anisotropy of the fibrous structure is high is in a preferable state, and for example, FIG. 2ab, particularly FIG. Further, for example, when the calculated directionality score of the measurement subject is compared with the ranking of the directionality score of the fibrous structure of the confocal image acquired in a standard subject of 50 or more women in their 20s to 60s, If the upper 30% or more, more preferably 20% or more, it can be said that the skin condition is preferable.

The thickness of the fibrous structure is the thickness of the fiber bundle that forms the fibrous structure (width in the direction perpendicular to the fiber direction). Usually, imaging is performed when the fibrous structure of the dermis is imaged under the same conditions. It can be expressed as an average value in the range.
The fiber bundle when the skin condition is good is thin overall, but when the fibrous structure changes due to aging or various damages, it gradually loses its fineness and becomes thicker in one direction, indicating deterioration of the skin condition.

An example of a method for measuring the thickness of the fibrous structure will be described.
“Specific depth plane” selected for the measurement site of the measurement subject is imaged with a confocal laser microscope, and an arbitrary number of samples within the imaging range are sampled. The average value can be the thickness of the fiber bundle. In addition, the ranking when the average values are rearranged by all measurement subjects can be used as an index used in the present invention as a relative score of thickness. These small average values and good score values indicate that the skin is in a preferable state.

The skin state estimated by the discrimination method of the present invention is, for example, elasticity / elasticity, tarmi, skin color, texture,
And the pores, usually one or more of the above skin conditions. In addition, although the site | part of the skin here is not specifically limited, such as a face, limbs, a neck part, and a trunk | drum, normally, it distinguishes about the skin state of a face. Hereinafter, various skin conditions and the effects of the fibrous structure will be described.

“Hariness / elasticity” is a property that the skin pushes back against a force applied in the horizontal direction or the vertical direction, or a property that deforms but tries to restore (restore) when the force is removed. For example, it is expressed by the viscoelastic properties of the skin.
When the fibrous structure is sharp, that is, when the fibrous structure is clearly present, or when the fiber bundle is highly anisotropic and finely present, the function as a cushion is high, and the elasticity / since the rich in elasticity, it can be said that the skin is rich in Hari bullets force, it is a youthful skin. Even when the anisotropy of the fibrous structure is high, its function as a cushion of the dermis that supports the epidermis is also high, so that the skin is rich and firm. On the other hand, if the fibrous structure is poor, the fibrous structure is isotropic, or if the fiber bundle is thick and the fibrous structure is poor, the dermis is poorly elastic and the skin is stressed. It can not be restored to the poor in Hari bullets force.

“Talmi” is a change in the shape of the skin in the direction of gravity that occurs as a result of the loss of elasticity and elasticity of the skin due to factors such as aging. In general, an image processing system such as VECTRA M3 (Canfield Imaging Systems CANFIELD Imaging Systems) is used to photograph a face in an upright position and a face in an obliquely inclined position, and a facial shape due to a difference in posture. It is evaluated by obtaining the difference.
When the fibrous structure is high, that is, when the fibrous structure is clearly present, when the fibrous structure is highly anisotropic, or when the fiber bundle is fine, the skin is firm and elastic as described above. Because it is rich and can resist the shape change in the direction of gravity, it is hard to cause tarmi.

“Skin color” is an element of the state of the skin that influences youthfulness and a healthy impression depending on the color and brightness of the skin. In general, it is measured with a spectrocolorimeter, a color difference meter, etc., for example, RGB, Munsell (lightness, hue, saturation), L * a * b, XYZ, L * C * h, Hunter Lab, etc. Can be displayed.
The skin color is greatly influenced by the presence of melanin in the epidermis and capillaries directly under the epidermis. If the fibrous structure is highly sharp, highly anisotropic, or fiber bundles are thin, collagen fibers Since the bundle is fine and full of dermis, the scattering of light entering from the skin surface becomes uniform, so that it becomes a bright skin color that shines from the inside of the skin. On the other hand, if the fibrous structure is low in definition, isotropic, or has a thick fiber bundle, the skin color becomes non-uniform and the skin becomes dull.

“Kime” refers to the shape of the skin surface, and the fineness / roughness of the skin pattern consisting of skin grooves (fine and shallow grooves that run vertically and horizontally across the skin surface) and skin hills (small bumps surrounded by skin grooves). Good or bad is evaluated by adjusting / distorting. Various display methods are known. For example, they are represented by texture parameters obtained by an epidermis tissue quantification method (Japanese Patent Laid-Open No. 2008-61892).
If the fibrous structure has high definition, high anisotropy, or thin fiber bundles, the elasticity of the dermis and the elasticity of the epidermis increase, resulting in a finely textured skin state. On the other hand, when the definition of the fibrous structure is low, the isotropic property is high, or the fiber bundle is thick, the dermis and epidermis are poorly stretchable, and the texture becomes rough and distorted.

A “pore” is a small hole (indentation) on the skin surface where the hair grows. For example, the evaluation is based on the total area of the pores in the observation range and the shape of the pores, and the presence of the pores is not noticeable, giving a youthful skin impression.
In general, as the face ages, the area of the pores increases (so-called pore opening), and the shape of the pores seen from the surface tends to become longer. This is presumably because the pores are also pulled in the extension direction as the skin is extended by talmi due to aging. Therefore, if the fibrous structure is highly defined, the anisotropy of the fibrous structure is high, or the fiber bundle is thin, as described above, it is difficult for the skin to become talmi, the pore area is small, and the circular shape It is. On the other hand, if the fibrous structure is low in definition, isotropic, or the fiber bundle is thick, the pore area is large and the shape is long.

In the discrimination method of the present invention, it is preferable that the analysis is performed by deriving a parameter representing the skin state by applying a fibrous structure feature obtained by measurement or estimation to an estimation formula obtained by multivariate analysis. The estimation formula can be created by performing correlation analysis and regression analysis between the fibrous structure feature quantity and the skin condition parameter using multivariate analysis software. As such software, software attached to the apparatus, commercially available software such as SPSS or SAS, or free software can be used, and is not particularly limited.
In addition, there are no particular limitations on the subjects who become measurement standards when creating the estimation formula, but preferably 30 or more, more preferably 50 or more, and even more preferably 100 or more ensure the accuracy of the analysis. Therefore, it is preferable. Further, it is preferable that the age is distributed in a wide range such as in the 20s to 60s, and an estimation formula that takes into account the age element may be created if necessary. In addition, it is preferable to have a gender and race, for example, a woman of yellow race.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded.

<Example 1> Discrimination of elasticity and elasticity based on the definition of the fibrous structure (1) Measurement of the definition of the fibrous structure About 1 to 1 mm of cheeks of 90 Japanese female subjects in their 20s and 60s The sharpness in the observation range was measured. The measurement is performed using a confocal laser microscope (VivaScope 1500 Plus; manufactured by Lucid, USA), a probe is placed on the cheek, and measurement is performed up to 180 μm in 3 μm depth steps. Then, the “specific depth plane” was selected and measured on the basis of the “depth plane where the fibrous structure is most clearly observed”. The acquired image was subjected to fast Fourier transform analysis for 1 to 512 cycles, and the values rearranged and ranked by the integrated values of 20 to 50 cycles were defined as relative scores of sharpness.
(2) Measurement of skin viscoelastic property The skin viscoelastic property value was measured at the same cheek site where the sharpness of the fibrous structure of the subject was measured. Specifically, using a skin viscoelasticity (elasticity) measuring device, cutometer MPA580 (registered trademark) (Courage + Khazaka, Germany), a probe having a hole with a diameter of 2 mm in the center of the device is measured. Using the infrared sensor, apply the total amount of skin height (final extension: Uf) drawn to the probe opening by negative pressure and applied to the skin surface, and the return amount of the skin immediately after negative pressure release (immediate contraction: Ur). And optically measured with an accuracy of 0.01 mm. The measurement was performed in a time-stress mode consisting of a basic operation step of deforming the skin by applying a negative pressure of 450 millihectopascal, releasing the negative pressure after 2 seconds, and relaxing for 2 seconds. A value obtained by dividing Ur by Uf (return rate) was defined as a skin viscoelastic property value (Ur / Uf) representing elasticity and elasticity. The closer this value is to 1, the better the skin is restored to deformation in the vertical direction, and the greater the elasticity and elasticity of the skin.
(3) Analysis Correlation analysis and regression analysis were performed using JMP ver. 6.0 (SAS), using the above-described measured fibrity of the fibrous structure (relative score) and skin viscoelastic property values ( FIG. 4). From this, it can be seen that there is a significant correlation between the definition of the fibrous structure and the skin viscoelastic property value, and it is possible to estimate the state of skin elasticity and elasticity using the definition of the fibrous structure as an index. .

<Example 2> Skin color discrimination based on the definition of the fibrous structure (1) Measurement of the definition of the fibrous structure As in Example 1, the definition (relative score) of the fibrous structure of the subject is measured. did.
(2) Color measurement of skin The color of the skin at the same cheek site where the sharpness of the fibrous structure of the subject was measured was measured with a spectrocolorimeter (CM-2600d; manufactured by Konica Minolta), Skin colorimetric b * values were obtained. This value indicates the yellowness level of the skin color, and the smaller the color, the more so-called youthful skin color.
(3) Analysis Correlation analysis and regression analysis were performed using JMP ver. 6.0 (SAS) using the measured fibrity of the fibrous structure and the colorimetric b * value of the skin (FIG. 5). ). Thus, there is a significant correlation between the sharpness of the fibrous structure and the colorimetric b * value of the skin, and the state of the skin color, particularly the youthfulness, with the sharpness of the fibrous structure as an index. It can be seen that the degree of can be estimated.

<Embodiment 3> Discrimination between elasticity and elasticity based on the estimated fibrity of the fibrous structure (1) Estimation of the fibrity of the fibrotic structure First, an equation for estimating the fibrous structure feature (sharpness) It was created according to Open 2011-101738. Specifically, in advance, Oite the subjects to obtain an estimate equation, the skin surface information using a confocal laser microscope (roughness information, color information), a fibrous structure feature quantity parameters (sharpness) Was measured. For unevenness information among skin surface information, parameters relating to unevenness information are converted into data of various color systems for color information using, for example, an epidermis tissue quantification method described in JP-A-2008-061892. For example, parameters related to color information were used. Using these parameters and sharpness as data, JMP ver.6.0 (SAS) is used to determine an estimation formula for estimating the fibrous structure feature (sharpness) from skin surface information by correlation analysis and multiple regression analysis. did.
Estimates of the sharpness obtained by substituting the skin surface information measured in the test subject into these estimation formulas, and the sharpness of the fibrous structure actually measured in the same observation range of the test subject as in Example 1. As a result of a correlation analysis with respect to the above, since a significant correlation was found between the two (FIG. 6), an estimate of the definition of the fibrous structure was provided for the subsequent analysis.
(2) Measurement of skin viscoelastic properties In the same manner as in Example 1, the skin viscoelastic property values representing elasticity and elasticity were measured in the same cheek region where the sharpness of the fibrous structure of the subject was estimated. .
(3) Analysis Using JMPver. 6.0 (SAS), correlation analysis and regression analysis were performed using the estimated fibrosis of the fibrous structure and the measured skin viscoelastic property values ( FIG. 7). As a result, there was a significant correlation between the fibrous structure definition and skin viscoelastic property values, and the state of skin elasticity and elasticity was also measured using the estimated fibrous structure definition as an index. It can be seen that can be estimated.

Example 4 Skin Color Discrimination Based on Estimated Fibrous Structure Sharpness (1) Estimation of Fibrous Structure Visibility Similar to Example 3, a subject's fibrous structure sharpness was estimated. .
(2) Skin colorimetry In the same manner as in Example 2, the skin color and the skin colorimetry b * value were measured at the same cheek site where the filarity of the subject's fibrous structure was estimated. .
(3) Analysis Using JMP ver. 6.0 (SAS), correlation analysis and regression analysis were performed using the estimated fibrosis of the fibrous structure and the measured skin colorimetric b * value. Performed (FIG. 8). As a result, there is a significant correlation between the estimated value of the definition of the fibrous structure and the colorimetric b * value of the skin, and even if the estimated definition of the fibrous structure is used as an index, It can be seen that the color state, particularly the degree of youthfulness, can be estimated.

  According to the present invention, it is possible to estimate the skin state simply and with high accuracy and non-invasively. This makes it possible to obtain useful information when examining, selecting and determining skin care and makeup methods, and can also be used for counseling regarding skin care and makeup methods. is there.

Claims (4)

For cosmetic purposes, it is characterized by estimating skin condition using fibrous structure information as an index,
The fibrous structure information is represented by one or more kinds of fibrous structure features selected from the definition of the fibrous structure, the anisotropy of the fiber bundle, and the thickness of the fiber bundle,
The skin condition is a skin color,
A skin condition discrimination method in which the skin condition is presumed to be good when the fibrous structure has high definition, the fiber bundle has high anisotropy, and / or the fiber bundle is thin.   The identification method according to claim 1, wherein the fibrous structure feature amount is measured using a confocal laser microscope.   The identification method according to claim 1, wherein the fibrous structure feature amount is estimated based on skin surface information.   The identification method according to any one of claims 1 to 3, wherein the estimation of the skin condition is performed using an estimation formula obtained by multivariate analysis.