Method for determining skin type, skin type determination device, and program

Abstract

The present invention makes an assessment of a skin on the basis of factors related to the elasticity of a skin. A method according to one embodiment of the present invention is for determining the skin type of a subject, from among skin types classified on the basis of the hardness of a horny layer, the density of collagen, and the density of blood vessels, which are factors related to the elasticity of a skin.

Description

Method for determining skin type, skin type determination device, and program

[0001] The present invention relates to a method for determining a skin type, a skin type determination device, and a program.

[0002] A decrease in skin elasticity has been known as one of the skin problems. For example, Patent Document 1 discloses a method for evaluating skin elasticity, in which the viscoelasticity of the surface layer of the skin is measured and the measured viscoelasticity is compared with a viscoelasticity reference value to evaluate skin care.

[0003] JP 2012-161371 A

[0004] However, it is believed that there are multiple factors that cause a decrease in skin elasticity, and the relationship between these multiple factors and the skin has not yet been clarified.

[0005] Therefore, an object of one embodiment of the present invention is to evaluate skin based on factors related to skin elasticity.

[0006] A method according to one embodiment of the present invention determines a subject's skin type from skin types classified based on factors that determine skin elasticity: stratum corneum hardness, collagen density, and blood vessel density.

[0007] According to an embodiment of the present invention, it is possible to determine a skin type based on factors related to skin elasticity.

[0008] FIG. 1 is a diagram for explaining the relationship between skin elasticity and four skin types according to one embodiment of the present invention. FIG. 2 is a diagram for explaining the relationship between stratum corneum hardness and four skin types according to one embodiment of the present invention. FIG. 3 is a diagram for explaining the relationship between collagen density and four skin types according to one embodiment of the present invention. FIG. 4 is a diagram for explaining the relationship between blood vessel density and four skin types according to one embodiment of the present invention. FIG. 5 is a classification table showing skin types classified based on stratum corneum hardness, collagen density, and blood vessel density, which are factors in skin elasticity according to one embodiment of the present invention. FIG. 6 is a diagram for explaining a classification tree from skin condition to four skin types according to one embodiment of the present invention. FIG. 7 is an overall configuration diagram according to one embodiment of the present invention. FIG. 8 is a functional block diagram of a skin type discrimination device according to one embodiment of the present invention. FIG. 9 is a flowchart of a process for discriminating a skin type according to one embodiment of the present invention. FIG. 10 is a block diagram showing an example of the hardware configuration of a skin type discrimination device according to one embodiment of the present invention.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] <Skin types based on factors affecting skin elasticity> First, we will explain how skin can be classified into four types based on factors affecting skin elasticity (specifically, stratum corneum hardness, collagen density, and blood vessel density).

[0011] First, the subjects' facial skin elasticity, the hardness of the stratum corneum, the collagen density of the subject's face, and the blood vessel density of the subject's face were measured. Next, the subjects were clustered using the measured values ​​of the facial skin elasticity, the hardness of the stratum corneum, the collagen density of the subject's face, and the blood vessel density of the subject's face as parameters, and the subjects were able to be classified into four clusters (four skin types (referred to as Type G, Type B1, Type B2, and Type B3)).

[0012] Below, with reference to Figures 1 to 5, we will explain the relationship between skin elasticity and the four skin types, the relationship between stratum corneum hardness and the four skin types, the relationship between collagen density and the four skin types, and the relationship between blood vessel density and the four skin types.

[0013] 1 is a diagram illustrating the relationship between skin elasticity and four skin types according to an embodiment of the present invention. As shown in FIG. 1, Type G had elastic skin (i.e., the value of skin elasticity (Ur / Uf) in FIG. 1 was large). On the other hand, Types B1, B2, and B3 had inelastic skin (i.e., the value of skin elasticity (Ur / Uf) in FIG. 1 was small).

[0014] <<Skin Elasticity>> Skin elasticity (also referred to as elasticity or viscoelasticity) will now be described. For example, an index of skin elasticity is Ur / Uf (also referred to as R7) calculated using a skin viscoelasticity measuring device such as Cutometer (registered trademark).

[0015] FIG. 2 shows the hardness of the stratum corneum (specifically, acoustic impedance [MNs / m 3 2 is a diagram illustrating the relationship between the hardness of the stratum corneum and the four skin types. As shown in Fig. 2, the stratum corneum of Type G, Type B1, and Type B2 was soft (i.e., the hardness value of the stratum corneum in Fig. 2 was small). On the other hand, the stratum corneum of Type B3 was hard (i.e., the hardness value of the stratum corneum in Fig. 2 was large).

[0016] <<Hardness of the stratum corneum>> Here, the hardness of the stratum corneum will be explained. For example, the index of hardness of the stratum corneum is a value measured using an acoustic microscope (specifically, acoustic impedance [MNs / m 3 ]).

[0017] 3 is a diagram illustrating the relationship between collagen density (specifically, volume filling rate [dimensionless quantity]) and four skin types according to one embodiment of the present invention. As shown in FIG. 3, Type G had a high collagen density (i.e., the collagen density value in FIG. 3 is large). On the other hand, Types B1, B2, and B3 had a low collagen density (i.e., the collagen density value in FIG. 3 is small).

[0018] <<Collagen Density>> Here, the collagen density will be described. For example, an index of collagen density is a value measured using an acoustic microscope (specifically, volume filling rate [dimensionless quantity]).

[0019] FIG. 4 is a diagram illustrating the relationship between blood vessel density (specifically, the proportion (percentage) of blood vessel structures in the field of view) and four skin types according to an embodiment of the present invention. As shown in FIG. 4, Type B1 had a low blood vessel density (i.e., the blood vessel density value in FIG. 4 is small). Type B2 had a high blood vessel density (i.e., the blood vessel density value in FIG. 4 is large). Type G and Type B3 had a medium blood vessel density (i.e., the blood vessel density value in FIG. 4 is between the value for Type B1 and the value for Type B2).

[0020] <<Blood Vessel Density>> Here, the blood vessel density will be described. For example, an index of blood vessel density is a value measured using optical coherence tomography (OCT) (specifically, the proportion (percentage) of blood vessel structures within the field of view).

[0021] Fig. 5 is a classification table showing skin types classified based on factors that determine skin elasticity, such as stratum corneum hardness, collagen density, and blood vessel density, according to one embodiment of the present invention. The relationships described in Figs. 1 to 4 can be summarized as shown in Fig. 5.

[0022] [Type G] Type G is a skin type with facial elasticity (specifically, greater elasticity than Types B1, B2, and B3). Type G has a soft stratum corneum (specifically, softer than Type B3), a high facial collagen density (specifically, higher than Types B1, B2, and B3), and a medium facial blood vessel density (specifically, higher than Type B1 and lower than Type B2).

[0023] Types B1, B2, and B3 are skin types in which facial skin lacks elasticity (specifically, is less elastic than Type G). Lacking elasticity in skin is classified into three types (Types B1, B2, and B3) based on factors that contribute to skin elasticity (specifically, the hardness of the stratum corneum, collagen density, and blood vessel density).

[0024] [Type B1] Type B1 has a soft stratum corneum on the face (specifically, softer than Type B3), a low collagen density on the face (specifically, lower than Type G), and a low blood vessel density on the face (specifically, lower than Types G, B2, and B3).

[0025] [Type B2] Type B2 has a soft stratum corneum (specifically, softer than Type B3), a low facial collagen density (specifically, lower than Type G), and a high facial blood vessel density (specifically, higher than Types G, B1, and B3).

[0026] [Type B3] Type B3 has a hard stratum corneum (specifically, harder than Types G, B1, and B2), a low facial collagen density (specifically, lower than Type G), and a medium facial blood vessel density (specifically, higher than Type B1 and lower than Type B2).

[0027] In addition, the representative values ​​(e.g., average values) of each value (i.e., elasticity, hardness of the stratum corneum, collagen density, blood vessel density) measured in individuals of each type (i.e., Type G, Type B1, Type B2, Type B3) may be used as the criteria for classifying skin types.

[0028] In this way, it was possible to classify skin types based on a combination of factors related to skin elasticity. For example, it was previously thought that a soft stratum corneum meant skin elasticity (and conversely, a hard stratum corneum meant skin inelasticity), but in types B1 and B2, the skin lacked elasticity despite the soft stratum corneum. Also, it was previously thought that a high blood vessel density meant skin elasticity (and conversely, a low blood vessel density meant skin inelasticity), but type B1 had a low blood vessel density, type B2 had a high blood vessel density, and type B3 had a medium blood vessel density.

[0029] Below, we will explain a method for determining which of the four skin types classified based on the above-mentioned skin elasticity factors (specifically, stratum corneum hardness, collagen density, and blood vessel density) a person has.

[0030] FIG. 6 is a diagram illustrating a classification tree from skin conditions into four skin types according to an embodiment of the present invention.

[0031] Machine learning was performed using training data indicating skin features (specifically, skin features extracted from facial images and skin measurement values) and skin types (the above-described G type, B1 type, B2 type, and B3 type), resulting in the generation of a classification tree (a tree indicating which skin type corresponds to which skin feature) as shown in Figure 6. As shown in Figure 6, of the skin features, (1) the score of wrinkles around the eyes, (2) the number of pores, (3) the score of wrinkles around the eyes, (4) the score of texture around the eyes, and (5) the range of pores are used as branching conditions.

[0032] A method for determining which of the four skin types a person has using such a classification tree or the like will be described.

[0033] <Overall Configuration> Fig. 7 is a diagram showing the overall configuration according to one embodiment of the present invention. Each of these components will be described below.

[0034] The skin type discrimination device 10 determines which of four skin types classified based on factors of skin elasticity (specifically, hardness of the stratum corneum, collagen density, and blood vessel density) the subject's 30 skin belongs to, based on the subject's skin condition (e.g., facial image and skin measurement values). The skin type discrimination device 10 is composed of one or more computers. The skin type discrimination device 10 will be described in detail later with reference to FIG. 8.

[0035] The skin condition acquisition device 20 is a device for acquiring information on the skin condition of the subject 30. For example, the information on the skin condition of the subject 30 is an image of the face of the subject 30 (e.g., an enlarged image of the facial skin of the subject 30) and measurement values ​​of the skin of the subject 30 (e.g., the amount of moisture, the amount of sebum, etc., of the skin of the subject 30). In this case, the skin condition acquisition device 20 has an image capturing function and a measurement function of the amount of moisture, the amount of sebum, etc.

[0036] 7, the skin type determination device 10 and the skin condition acquisition device 20 are described as separate devices, but the skin type determination device 10 and the skin condition acquisition device 20 may be implemented as a single device. Furthermore, the skin type determination device 10 and the skin condition acquisition device 20 may be devices placed in front of a store selling cosmetics or the like, or may be implemented as a web or application on a device such as a smartphone of the subject 30.

[0037] <Functional Block> Fig. 8 is a functional block diagram of a skin type discrimination device 10 according to an embodiment of the present invention. The skin type discrimination device 10 can include an acquisition unit 101, an extraction unit 102, a skin type discrimination unit 103, and a recommendation unit 104. Furthermore, the skin type discrimination device 10 can function as the acquisition unit 101, the extraction unit 102, the skin type discrimination unit 103, and the recommendation unit 104 by executing a program.

[0038] The acquisition unit 101 acquires information on the skin condition of the subject 30. Specifically, the acquisition unit 101 acquires information on the skin condition of the subject 30 acquired by the skin condition acquisition device 20.

[0039] <Skin Condition Information> Here, the skin condition information will be described. For example, the skin condition information of the subject 30 is an image of the face of the subject 30 and measurement values ​​of the skin of the subject 30. Note that the skin condition information of the subject 30 may be at least one of an image of the face of the subject 30, measurement values ​​of the skin of the subject 30, and responses of the subject 30 to a questionnaire regarding the skin condition.

[0040] <<Facial Image>> For example, the facial image of the subject 30 is an enlarged image of the facial skin of the subject 30 .

[0041] <<Skin Measurement Values>> For example, the skin measurement values ​​of the subject 30 include the moisture amount, sebum amount, skin gas amount, skin sensitivity, and the like of the subject 30's skin.

[0042] The extraction unit 102 extracts the skin characteristics of the subject 30 based on the information on the skin condition of the subject 30 acquired by the acquisition unit 101.

[0043] <Skin Characteristics> Skin characteristics will now be described. For example, skin characteristics include wrinkles around the eyes (for example, a score based on a comprehensive evaluation (a dimensionless quantity)) and the number of pores (for example, the number / cm ２ ), the texture around the mouth (e.g., a score based on a comprehensive evaluation (a dimensionless quantity)), and the extent of the pores (i.e., the area they occupy, e.g., mm ２ / cm ２ ) and at least one of.

[0044] The skin type determination unit 103 uses a classification tree or the like to determine which of the four skin types the subject's 30 skin is based on the skin characteristics of the subject 30 extracted by the extraction unit 102.

[0045] <Skin Type> The skin types will now be described. The four skin types are Type G, Type B1, Type B2, and Type B3 as described above.

[0046] The recommendation unit 104 recommends (for example, displays on a screen) information on beauty products or services that suit the skin type of the subject 30 determined by the skin type determination unit 103. Specifically, the recommendation unit 104 refers to a correspondence between a predetermined "skin type" and "information on beauty products or services that are suitable for that skin type," and extracts and presents information on beauty products or services that suit the skin type of the subject 30.

[0047] <Information about beauty products or services> Here, information about beauty products or services will be described. For example, information about beauty products or services includes information about cosmetics for skin care or makeup, information about food and beverages such as supplements, information about cosmetic tools, information about beauty equipment, information about aesthetics, etc. For example, information about beauty products or services includes the name and price of the product or service.

[0048] Method FIG. 9 is a flowchart of a process for determining skin type according to one embodiment of the present invention.

[0049] In step 101 (S101), the acquisition unit 101 acquires information on the skin condition of the subject 30. For example, the information on the skin condition of the subject 30 is an image of the face of the subject 30 (e.g., an enlarged image of the facial skin of the subject 30) and measurement values ​​of the skin of the subject 30 (e.g., the moisture content, sebum content, etc. of the skin of the subject 30). Note that the information on the skin condition of the subject 30 may be at least one of the image of the face of the subject 30, the measurement values ​​of the skin of the subject 30, and the subject 30's response to a questionnaire regarding the skin condition.

[0050] In step 102 (S102), the extraction unit 102 extracts skin features of the subject 30 based on the information on the skin condition of the subject 30 acquired in S101. For example, the skin features include at least one of wrinkles around the eyes, the number of pores, the texture around the mouth, and the area of ​​the pores.

[0051] In step 103 (S103), the skin type determination unit 103 uses a classification tree or the like to determine which of the four skin types (specifically, Type G, Type B1, Type B2, or Type B3 described above) the subject's 30 skin belongs to, based on the skin characteristics of the subject 30 extracted in S102.

[0052] In step 104 (S104), the recommendation unit 104 recommends (for example, displays on a screen) information on beauty products or services that suit the skin type of the subject 30 determined in S103.

[0053] <Effects> In one embodiment of the present invention, it is possible to determine which of four skin types a subject's skin type is classified based on internal factors of skin elasticity (specifically, stratum corneum hardness, collagen density, and blood vessel density) based on the subject's skin condition (e.g., facial images and skin measurement values). This makes it possible to evaluate skin based on factors of skin elasticity, which was not possible with skin evaluations using skin viscoelasticity measuring devices such as cutometers. Furthermore, because it is possible to determine the subject's skin type based on the subject's skin condition (e.g., facial images and skin measurement values), there is no need to use large equipment to measure stratum corneum hardness, collagen density, and blood vessel density.

[0054] <Hardware Configuration> Fig. 10 is a block diagram showing an example of the hardware configuration of a skin type discrimination device 10 according to one embodiment of the present invention. The skin type discrimination device 10 has a CPU (Central Processing Unit) 1, a ROM (Read Only Memory) 2, and a RAM (Random Access Memory) 3. The CPU 1, ROM 2, and RAM 3 form a so-called computer. The skin type discrimination device 10 may also have an auxiliary storage device 4, a display device 5, an operation device 6, an I / F (Interface) device 7, and a drive device 8. The hardware components of the skin type discrimination device 10 are connected to each other via a bus B.

[0055] The CPU 1 is a computing device that executes various programs installed in the auxiliary storage device 4 .

[0056] The ROM 2 is a non-volatile memory and functions as a main storage device that stores various programs, data, etc. required for the CPU 1 to execute various programs installed in the auxiliary storage device 4. Specifically, the ROM 2 functions as a main storage device that stores boot programs such as a Basic Input / Output System (BIOS) and an Extensible Firmware Interface (EFI).

[0057] The RAM 3 is a volatile memory such as a dynamic random access memory (DRAM) or a static random access memory (SRAM). The RAM 3 functions as a main storage device that provides a working area in which various programs installed in the auxiliary storage device 4 are expanded when the CPU 1 executes them.

[0058] The auxiliary storage device 4 is an auxiliary storage device that stores various programs and information used when the various programs are executed.

[0059] The display device 5 is a display device that displays the internal state of the skin type discrimination device 10 and the like.

[0060] The operation device 6 is an input device through which an administrator of the skin type discrimination device 10 inputs various instructions to the skin type discrimination device 10 .

[0061] The I / F device 7 is a communication device that connects to a network and communicates with other devices.

[0062] The drive device 8 is a device for loading a storage medium 9. The storage medium 9 here includes media that record information optically, electrically, or magnetically, such as CD-ROMs, flexible disks, and magneto-optical disks. The storage medium 9 may also include semiconductor memories that record information electrically, such as EPROMs (Erasable Programmable Read Only Memory) and flash memories.

[0063] The various programs to be installed in the auxiliary storage device 4 are installed, for example, by setting the distributed storage medium 9 in the drive device 8 and reading the various programs recorded on the storage medium 9 by the drive device 8. Alternatively, the various programs to be installed in the auxiliary storage device 4 may be installed by being downloaded from a network via the I / F device 7.

[0064] Although the examples of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above, and various modifications and changes are possible within the scope of the gist of the present invention as set forth in the claims.

[0065] This international application claims priority to Japanese Patent Application No. 2021-203160, filed on December 15, 2021, the entire contents of which are hereby incorporated by reference into this international application.

[0066] REFERENCE SIGNS LIST 10 Skin type determination device 20 Skin condition acquisition device 30 Subject 101 Acquisition unit 102 Extraction unit 103 Skin type determination unit 104 Recommendation unit

Claims

1. A method for determining the skin type of a subject from skin types classified based on the hardness of the stratum corneum, the density of collagen, and the density of blood vessels, which are factors of skin elasticity.

2. The method according to claim 1, wherein the skin type is classified into a type with high elasticity and a type with low elasticity.

3. The type with low elasticity is further A type in which the stratum corneum is soft, the density of collagen is low, and the density of blood vessels is low, and A type in which the stratum corneum is soft, the density of collagen is low, and the density of blood vessels is high, and The method according to claim 2, wherein the type is classified into a type in which the stratum corneum is hard, the density of collagen is low, and the density of blood vessels is medium.

4. Obtaining an image of the subject's face and measurement values of the subject's skin, Extracting the characteristics of the subject's skin based on the image of the subject's face and the measurement values of the subject's skin, Further including determining, from the characteristics of the subject's skin, which skin type among the skin types classified based on the hardness of the stratum corneum, the density of collagen, and the density of blood vessels, which are factors of skin elasticity, the method according to any one of claims 1 to 3.

5. The method according to claim 4, wherein the skin characteristics include at least one of wrinkles around the eyes, the number of pores, texture around the mouth, and the range of pores.

6. Further including recommending information on products or services related to beauty suitable for the skin type of the subject, the method according to claim 1.

7. A skin type determination device including a skin type determination unit that determines the skin type of a subject from skin types classified based on the hardness of the stratum corneum, the density of collagen, and the density of blood vessels, which are factors of skin elasticity.

8. A program for causing a skin type discrimination device to function as a skin type discrimination unit that discriminates the skin type of a subject from skin types classified based on the hardness of the stratum corneum, the density of collagen, and the density of blood vessels, which are factors of skin elasticity.