JP2008046061A - Discriminant technique of skin with interference light - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple but highly precise technique replacing beauty of skin to third party's eye to objective numerical values by using iridescence shown by horny layer cell itself as an evaluation index to provide information useful to discriminate skin status and to appropriately select articles of toilet. <P>SOLUTION: Of discriminant techniques of skin, the present discriminant technique of skin is characterized by irradiating a horny layer cell with light at angle of 0 to 45 degrees, of the horny layer cell taken from skin, by observing interference light obtained via reflection from the horny layer cell, and by discriminating as more beautiful skin to higher brightness degree of iridescence of the interference light concerned. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a skin discrimination method, and more particularly to a skin discrimination method using the appearance of stratum corneum cells by interference light as an index.

  Recognizing that the skin is beautiful by a third party is one of the great wishes of many people as well as women. For this reason, research and development of cosmetics and beauty methods for showing beautiful skin are being actively conducted. However, since the skin condition and characteristics vary greatly depending on the individual, and also change depending on the aging and living environment, in order to properly select the type of cosmetics, makeup method, skin care method, etc. It is necessary to accurately and objectively determine in what state the target skin looks like to a third party. For example, in a department store cosmetics store, a pharmacy, or a cosmetic store, a simple method for evaluating the skin condition and the degree of beauty of a subject is required. Such skin beauty is expressed by spots, wrinkles, acne, etc. The negative factor is “there is no skin trouble”, the fineness of the texture, the uniformity of the texture direction, smoothness, moist feeling, etc. From various survey results, it is clarified that “total beauty”, which is a positive factor expressed in, is an important factor.

  This kind of “total beauty” is formed by a number of elements that are complexly related to each other, and skin evaluation specialists analyze the measurement results based on their expertise. Or visual sensory evaluation was necessary. In that case, it is also necessary to have multiple skin assessment specialists, their training and training, and further analysis of the collected data, and it is difficult to accurately and easily evaluate visual “total beauty”. there were. For this reason, as an objective evaluation technique of “total beauty”, for example, a method / apparatus that focuses on the skin surface and measures and evaluates three-dimensional shape data of a replica of the skin surface (for example, Patent Document 1). Patent Document 2, Patent Document 3, and Patent Document 4) are disclosed. On the other hand, paying attention to the microscopic stratum corneum and stratum corneum cells that make up the skin surface, using adhesive tape etc. from parts such as the cheeks of the face, collecting stratum corneum cells by stripping, The shape is clarified by staining, and the area, volume, thickness, arrangement regularity of stratum corneum cells, or the degree of peeling of stratum corneum cells are measured, and the values are used as index values for the barrier function, skin quality, and skin properties. The technique which tries to discriminate | determine such skin conditions is disclosed (for example, refer patent document 5, patent document 6, patent document 7). As a result, skin surface information can be collected and processed at high speed and with high accuracy, or the characteristics of micro stratum corneum and stratum corneum cells can be confirmed. The correlation is not very good, but it can be said that the replacement of the subjective value with the objective value, which was the original purpose, was not realized. This is also due to the fact that unknown properties of stratum corneum cells constituting the actual skin surface were not clarified.

  On the other hand, in recent years, the progress of visualization technology of the surface structure and internal structure of an object using a light wave region is remarkable. For example, in a microscope and a microscope, a technique for obtaining a high-resolution image at high speed (see Patent Documents 8 and 9) is disclosed, and three-dimensional ultrahigh-precision observation is possible. In addition, as an application of optical tomography, especially optical coherence (OCT) technology in vivo (internal organs, vascular system) and skin, the layered structure of the skin is measured by the low-interference optical interferometry using the interference light phenomenon. An apparatus (see Patent Documents 10 and 11) is also disclosed, which facilitates observation of microscopic skin. For example, a skin external preparation (see Patent Documents 12 and 13) that evaluates a lamella structure between stratum corneum cells in human skin using a microscope and regenerates the lamella structure has also been reported. However, it was not known at all that the stratum corneum cells themselves showed a rainbow color, and that the brightness of the rainbow color and the beauty of the skin were related. Moreover, it was not known at all that the rainbow color which such a stratum corneum cell itself shows was stable by the process of a heat | fever or a solvent.

JP 05-146212 A JP 05-329133 A Japanese Patent Laid-Open No. 04-305113 JP 61-64232 A Japanese Patent Laid-Open No. 10-142224 JP 2000-116623 A JP 2001-013138 A Japanese Patent Application Laid-Open No. 06-088889 JP 10-307262 A Japanese Patent Laid-Open No. 10-153550 JP 2006-000385 A JP 2003-238341 A JP 2006-045186 A

  The present invention has been made under such circumstances, and in order to give useful information for discrimination of skin condition and appropriate selection of cosmetics, the rainbow color indicated by the stratum corneum cell itself is used as an evaluation index. It is an object of the present invention to provide a simple and highly accurate technique for replacing the beauty of the skin reflected in the eyes of a person with an objective numerical value.

  As a result of repeated studies on the beauty of the skin, the present inventors have found that the causation between the degree of iridescence due to the interference light of microscopic stratum corneum cells collected from the skin and the beauty of the macro skin. The inventors have found a technique capable of showing the beauty of the skin with objective numerical values, characterized by using a relationship, and have completed the invention. That is, the present invention is as follows.

(1) A skin discrimination method, in which stratum corneum cells collected from the skin are irradiated with light at an angle of 0 to 45 degrees with respect to the stratum corneum cells, and interference light obtained by reflection from the stratum corneum cells is obtained. A method of distinguishing skin, characterized by observing and distinguishing the degree of iridescence of the interference light as an index.
(2) The method for distinguishing skin according to (1), characterized in that the higher the brightness of the rainbow color is, the more beautiful the skin is.
(3) The skin discrimination method according to (1) or (2), wherein the stratum corneum cells are collected by a physical abrasion method.
(4) The skin discrimination method according to any one of (1) to (3), wherein stratum corneum cells are observed under coaxial epi-illumination.
(5) Any one of (1) to (4) is characterized in that a standard sample of the rainbow color brightness of interference light is prepared in advance, and the brightness of the rainbow color is identified by comparison with a rough evaluation sample. The skin discrimination method according to one.
(6) The iridescence in the stratum corneum cells is stable to heating at 100 ° C. and a solvent treatment, and the skin according to any one of (1) to (5) Identification method.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which can replace the beauty of the skin reflected in the eyes of a third party with an objective numerical value quickly and with high precision can be provided. As a result, high accuracy, short time, low cost and reliability in the advice of skin conditions, selection of appropriate cosmetics, enjoyment of the effects of using them, and evaluation of cosmetics, etc. at sales sites. Can contribute to sex.

  The present invention relates to a skin discrimination method, in which stratum corneum cells collected from the skin are irradiated with light at an angle of 0 to 45 degrees with respect to the stratum corneum cells and reflected from the stratum corneum cells. The higher the degree of rainbow-colored shine of the interference light, the better the skin is identified. A more detailed description will be given below.

  As a method for collecting stratum corneum cells from the skin, it is possible to use a commercially available adhesive tape, but it is particularly preferable to collect by a physical abrasion method without using a tape stripping method. Fig. 1 shows an example of sampling by physical abrasion method. 1) Rub the skin without applying force with a brush. 2) Drop stratum corneum cells attached to the brush onto an observation table such as a slide glass. Make observations. The instrument used for the physical rubbing method is not limited to a brush, and a tool such as a sponge or a spatula may be used. FIG. 2 shows an image image obtained by observing the stratum corneum cells by a tape-stripping method using an adhesive tape, which is often used as a standard method, and a physical abrasion method, which is a sampling method of the present invention, using a coaxial epi-illumination microscope. From FIG. 2, in the stratum corneum cells by the tape stripping method, a slight rainbow color that is interference light may be observed at the boundary where the stratum corneum cells overlap, whereas the stratum corneum cells by the physical abrasion method are observed. Then, each one is observed, and the rainbow-colored brightness can be clearly observed from the entire surface of each one stratum corneum cell. In other words, in both methods, the level of iridescent brightness observed in the observation of the degree of iridescent brightness is completely different, and in the collection of stratum corneum cells by the physical abrasion method, as described later, its clearness is clear. The skin can be differentiated using the brightness of the rainbow color as an index.

  The iridescent brightness of the stratum corneum cells collected by physical rubbing can clearly distinguish the differences in parts of each part of the body. For example, the iridescence of stratum corneum cells such as the inner forearm, thigh, and abdomen is strong, whereas the iridescence of stratum corneum cells in the exposed areas such as the cheek, forehead and palm weak. The rainbow-colored shine of the stratum corneum is strong, the skin of the inner forearm and thigh is clearly beautiful, but the rainbow-colored shine of the stratum corneum is weak, the skin of the cheek and forehead is relatively beautiful It's hard to say. From this, it is possible to distinguish that the higher the rainbow color brightness, the more beautiful the skin, using the rainbow color brightness as an index. Such discrimination can be used sufficiently and accurately not only in the differentiation of individual differences in individuals but also in the identification of individual differences, which is a comparison of identical parts, as shown in the examples described later.

The interference light is iridescent brightness observed in the interference light phenomenon. For example, in a single-layer film having a film thickness d as shown in FIG. 3, the light beam λ is refracted on the film surface having a film thickness d and a refractive index n, then reflected on the lower surface of the film and refracted in the X direction. The existence of an interference light phenomenon in which the light beam λ1 is reflected on the film surface and refracted in the X direction, causes thin film interference with the light beam λ in the X direction, and exhibits iridescent interference light is generally well known. Therefore, as such a condition, there is a case where the interference light obtained by being reflected from the stratum corneum cells can be observed by irradiating the stratum corneum cells with an angle of 0 to 45 degrees. The relationship between the film thickness and the interference light is as follows. In FIG. 3, the incident light is coaxially reflected in FIG. 3 with the medium refractive index n0 being 1.0 for air and the film refractive index n being 1.5 for stratum corneum cells. When 0 is applied to θ as the normal incidence condition of the type video microscope, the relational expression (1) between the film thickness and the theoretical value of the wavelength of the interference light is derived.
d = (1m + 1) λ / 6 (1)

  FIG. 4 shows the relationship between the thickness (film thickness) of the stratum corneum and the wavelength of the interference light, calculated using Equation (1). The thickness of the stratum corneum cells is not uniform at all, and is usually in the range of 100 to 300 nm and has a partial unevenness of several tens of nanometers, which reflects the difference in the partial thickness of the stratum corneum cells. Thus, it is assumed that the color of the interference light has changed and has a iridescent glow.

  A microscope suitable for use in the observation includes, for example, a microscope equipped with a coaxial incident type lens. Microscopes can observe microscopic images of the microscopic world. In addition to observation and recording functions, digital image processing is integrated with CCD cameras and computer functions. Analysis by two- and three-dimensional measurement of angle, area, etc. can also be performed. Examples of such a video microscope include Keyence Corporation digital microscope VHX series, Yamato Scientific Co., Ltd. digital microscope KH3000 type, Matsusada Precision Co., Ltd. digital microscope mz series, and the like. Coaxial epi-illumination (illumination) is an illumination method in which observation is performed using a half mirror so that the optical axis of the illumination coincides with the optical axis of the observation camera. Oblique illumination (ring illumination, etc.) and transmitted illumination do not allow the observation of the iridescence of stratum corneum cells, but by using such a coaxial epi-illumination lens, the above-mentioned interference light phenomenon conditions are met. It is a reason that the rainbow color due to the interference light can be grasped.

  The iridescent brightness of the interference light of the stratum corneum cells is objectively determined by standardizing (scoring) the degree of iridescent brightness in advance and performing a visual evaluation of the new stratum corneum cells based on the criteria. Can be evaluated. An example is shown in FIG. That is, a six-step reference photograph (rainbow color score) is prepared in advance from the maximum (rank 5) to the minimum (rank 0) in the degree of iridescence of the stratum corneum cells. 50 or more stratum corneum cells were collected from the subject's skin using a physical abrasion method, and 10 to 20 randomly selected stratum corneum cells were scored visually against a reference photograph, The average value of the 10 to 20 scores is defined as the rainbow color score of the subject.

  The rainbow-colored brilliance in the stratum corneum cells observed in this manner is very unlikely to change with respect to heating or treatment with a solvent, and is a characteristic of stable stratum corneum cells and is considered to be highly reliable. For example, after the collected stratum corneum was left in a high-temperature box at 100 ° C. for 24 hours, no difference was observed in the rainbow brightness of the stratum corneum before and after heating (see FIG. 6). In addition, the skin surface of the inner part of the human forearm is degreased for 20 minutes by the cup method using an acetone-ether solution, and then the rainbow color glow of the stratum corneum cells is observed at the treated and untreated sites. When compared, no difference was recognized. From this, it is presumed that the rainbow-colored brightness is not caused by normal proteins or lipids that are altered by heat treatment or solvent treatment.

  On the other hand, when an oil agent such as squalane or sebum component is applied to the stratum corneum cells, the rainbow brightness (rainbow color score) decreases. This is because the interference light phenomenon does not occur in FIG. 3 because the refractive indexes of both the single layer film and the medium in contact with the single layer film are close. In addition, the degree of brightness of the rainbow color is obvious, and the rainbow color score of the exposed part such as the cheek, forehead and palm is high. Low. When the skin is irradiated with ultraviolet rays, the rainbow color score of the stratum corneum cells may decrease, the difference in the rainbow color score due to the presence or absence of skin exposure, the disorder of the horny layer cell surface morphology and the thickness due to UV exposure The influence of the influence on the interference light phenomenon can be considered. There is also a report (see Patent Document 12) that points out that the rainbow color is a lamellar structure, but the rainbow color of the present invention and the rainbow color of these patent documents are identical. In these documents, since there is no examination of thermal stability and solvent stability, there is room for doubt, and in the iridescence of the present invention, heating, solvent treatment, oil coating, ultraviolet irradiation, etc. From these results, it can be inferred that the rainbow-colored brilliance is caused by the interference light phenomenon due to the thickness of the stratum corneum cells and the surface condition.

  Hereinafter, the present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereby.

  We investigated the correlation between the degree of iridescence of stratum corneum cells and the beauty of the skin. Photographing cheeks (2cm * 2cm area centered on the intersection of the corner of the eye and the nose) of 58 female subjects in their 10s and 50s using a commercially available digital microscope 30 minutes after washing their face Then, stratum corneum cells were collected by a physical rubbing method using a brush, and a photograph was taken with a video microscope VHX-100 equipped with a coaxial incident type lens VH-Z250 manufactured by Keyence Corporation. Next, skin moisture transpiration (TEWL), moisture content, sebum content, and skin elasticity were measured using Integral Corporation's Temometer TM210, Corneometer CM820, Sebetter SM810, and Cutometer SEM575. Furthermore, replica specimens were collected from 2 cm * 2 cm of the same site using Asahi Biomed's silicon ABS-01-WW, and using a high-precision three-dimensional image processing apparatus LIP-50 of Science Systems, Inc. From the obtained three-dimensional shape data, Ra (arithmetic average roughness) and Rz (ten-point average roughness), which are JIS roughness shape parameters, were calculated. Next, using a 10-step reference photograph (see FIG. 7) for evaluating the beauty of the skin prepared in advance, 58 female photographs were scored on 3 professional evaluators. The average value of the name was defined as the skin beauty of the photo. The evaluation of stratum corneum cells is based on a reference photograph (rainbow color score, see FIG. 5), as well as the beauty of skin. It was defined and calculated.

  Spearman rank correlation analysis between skin beauty and iridescent score of stratum corneum cells, TEWL, water content, sebum content, skin elasticity, Ra and Rz obtained as described above, and the correlation coefficient Table 1 shows. Since Table 1 shows a significant and very high correlation between the beauty of the skin and the rainbow color score, TEWL, the amount of water and sebum, and the physical characteristics of the skin, which are physiological indices of the skin It can be seen that the degree of iridescence of the stratum corneum cells is very effective for evaluating the beauty of the skin, compared to Ra and Rz of skin elasticity or skin surface characteristics.

  In Example 1, the cheek part was replaced with the inner part of the forearm, analysis was performed in the same manner as in Example 1, and the results are shown in Table 2. From Table 2, it can be seen that the iridescent brightness of the stratum corneum cells is also very effective for evaluating the beauty of the skin even in the inner part of the forearm.

  We examined the difference in rainbow-colored brightness of stratum corneum cells by body part. The rainbow color score (average value of 6 persons) was calculated in the same manner as in Example 1 for 10 sites of 6 female subjects in their 20s to 50s. The results are shown in Table 3. According to Table 3, the rainbow color score of the stratum corneum cells is large in the region where the skin on the inner side of the arm and the thigh is beautiful, but in the region where the skin is not relatively beautiful such as the cheek, forehead and palm The iridescent score of the cells tended to be small. From this, it can be seen that the higher the rainbow color brightness, the more beautiful the skin, with the rainbow color brightness as an index.

  The effect of the depth direction of the skin on the iridescent brightness of stratum corneum cells was examined. 30 minutes after washing the face of the female subject's cheek in Example 3, tape stripping was performed 3 times using a commercially available adhesive tape, and the stratum corneum cells were subjected to physical abrasion for each stripping frequency. The rainbow color score (average value of 6 persons) was calculated in the same manner as in Example 1. The rainbow color score tended to be as large as 3.0 for the third time, compared with 1.1 for the first time. This is presumed to be due to the surface morphology of the stratum corneum cells being prepared by receiving external stimuli in the underlying stratum corneum cells. In addition, compared to the skin before tape stripping, the skin subjected to tape stripping twice was evaluated beautifully, so that it can be discriminated that the skin is more beautiful as the rainbow color shine degree is higher.

  According to the present invention, it is possible to provide a technique capable of quickly and accurately replacing the beauty of the skin reflected in the eyes of a third party with an objective numerical value. As a result, high accuracy, short time, low cost and reliability in the advice of skin conditions, selection of appropriate cosmetics, enjoyment of the effects of using them, and evaluation of cosmetics, etc. at sales sites. Can contribute to sex.

It is a figure which shows the physical abrasion method which is a stratum corneum cell collection method for this invention. It is a figure which shows the influence on the brightness of the rainbow color of a horny layer cell by the difference in a collection method (drawing substitute photograph). It is a figure which shows description of an interference light phenomenon. It is a figure which shows the relationship between the thickness of a stratum corneum cell, and the wavelength of interference light. It is a figure which shows the method of evaluating the iridescent brightness degree (rainbow color score) of a stratum corneum cell (drawing substitute photograph). It is a figure which shows the influence on the rainbow brightness of the stratum corneum cell of heat processing (drawing substitute photograph). It is a 10-step reference photo for evaluation used to evaluate the beauty of the skin (drawing substitute photo).

Claims (6)

It is a skin discrimination method, irradiating the stratum corneum cells collected from the skin at an angle of 0 to 45 degrees with respect to the stratum corneum cells, observing the interference light obtained by reflection from the stratum corneum cells, A method for distinguishing a skin, comprising distinguishing the degree of iridescence of the interference light as an index. 2. The method of distinguishing skin according to claim 1, wherein the higher the brightness of the iridescent, the more beautiful the skin is identified. The method of distinguishing skin according to claim 1 or 2, wherein the stratum corneum cells are collected by a physical abrasion method. The method for distinguishing skin according to any one of claims 1 to 3, wherein the stratum corneum cells are observed under coaxial epi-illumination. The rainbow-colored brightness standard sample of interference light is prepared in advance, and the rainbow-colored brightness level is identified by comparison with an approximate evaluation sample, according to any one of claims 1 to 4. Skin discrimination method. The method for distinguishing skin according to any one of claims 1 to 5, wherein the rainbow-colored brilliance in the stratum corneum cells is stable to heating at 100 ° C and solvent treatment.