JP4517800B2 - Measuring device for optical properties of skin - Google Patents

Description

  The present invention relates to a measuring apparatus that can express an impression of skin appearance based on optical measurement values such as skin transparency and color information.

  The impression of the appearance of the skin largely depends on the transparency of the skin (internal scattering state) and the color information such as the skin color, the stain, and the bear as the basic tone.

  VRM (video reflectometry) is generally known as a method for measuring the transparency of an object. This is to collect and irradiate various light such as laser and white light on the object surface and measure the amount of back reflection of the internally scattered light. The more transparent object, the light reflection near the condensing point (internal The range of back reflection of scattered light is increased.

  Also, a device such as optical CT is known as a device for detecting transmitted scattered light of a strongly scattering object such as skin and measuring the internal information nondestructively. There has also been proposed one that can obtain information in the depth direction of the above (Patent Document 1).

On the other hand, measurement and analysis of gloss amount and color information (L ^* a ^* b ^*, etc.) are performed by illuminating a certain area of the skin without using a light collecting means and detecting the reflected light. In addition, the melanin component amount, the hemoglobin component amount, and the like are obtained by component analysis of the RGB intensity vectors of the image (Patent Document 2).

Japanese Patent Laid-Open No. 10-82732 JP 2002-200050 A

  When measuring skin transparency and color information as factors that affect the appearance of the skin, it is desirable to measure them simultaneously because the blood flow is likely to change due to changes in the external environment and psychological environment. However, conventional devices cannot measure transparency and color information at the same time.

  On the other hand, the present invention makes it possible to measure the transparency and color information of the skin almost simultaneously, and further associates the transparency and color information thus measured with the impression of the appearance of the skin, The objective is to be able to express the impression of appearance as an objective numerical value using transparency and color information.

  In order to achieve the above-mentioned object, the present inventors continuously switch and irradiate the apparatus for detecting and analyzing the reflected light from the skin with the condensed light and the parallel light without contact with the skin. It is effective to provide an irradiating means that can be used. Further, as an index of transparency, for example, an attenuation coefficient is used, and when this and color information are subjected to multiple regression analysis on the impression score of the skin appearance, It was found that when color information was measured almost simultaneously, an extremely high correlation was obtained between these and the impression score.

That is, the present invention provides (A), (B) and (C):
(A) Irradiation means capable of continuously switching and irradiating condensed light and parallel light in a non-contact manner on the skin surface;
(B) a transparency measuring means for detecting reflected light of the condensed light irradiated on the skin and calculating an attenuation coefficient (μ _eff ), an absorption coefficient (μ _a ), or an equivalent scattering coefficient (μ _s ′);
(C) Provided is a measuring device for optical properties of skin, which includes colorimetric means for detecting reflected light of parallel light irradiated on the skin and measuring color information.

In particular, in this measuring apparatus, the amount of melanin and the amount of hemoglobin are calculated from the color information, and the hemoglobin of an arbitrary subject is calculated based on the regression equation of the amount of hemoglobin, the amount of melanin, the attenuation coefficient (μ _eff ), and the skin appearance impression score. An aspect is provided that includes a calculation means for outputting an impression score of the skin appearance of the subject from the amount, the amount of melanin, and the attenuation coefficient (μ _eff ).

The present invention also provides:
(A) irradiating the skin surface in a non-contact manner by continuously switching and irradiating condensed light and parallel light;
(B) detecting the reflected light of the condensed light irradiated on the skin, calculating the attenuation coefficient (μ _eff ), absorption coefficient (μ _a ) or equivalent scattering coefficient (μ _s ′);
(C) To provide a method for measuring the optical properties of skin by detecting reflected light of parallel light irradiated on the skin and measuring color information.

Further, according to the present invention, in the measurement method described above, the amount of melanin and the amount of hemoglobin are calculated from the color information, and a regression equation of the melanin amount, the amount of hemoglobin, the attenuation coefficient (μ _eff ), and the impression score of the skin appearance is obtained. Based on the regression equation, a skin evaluation method for obtaining a score of an impression of the skin appearance of the subject from the amount of hemoglobin, the amount of melanin and the attenuation coefficient of an arbitrary subject is provided.

According to the measuring device of the present invention, the condensed light and the parallel light can be continuously switched and irradiated on the skin surface in a non-contact manner, so that the condensed light and the parallel light are instantaneously switched at almost the shutter speed. The reflected light of the condensed light and the reflected light of the parallel light can be detected almost simultaneously. Therefore, by detecting the reflected light of the collected light, the attenuation coefficient (μ _eff ), absorption coefficient (μ _a ) or equivalent scattering coefficient (μ _s ′) calculated as an index of skin transparency, and reflection of parallel light Melanin amount, hemoglobin amount, etc. calculated from light color information can be obtained as skin measurement values at the same point, and these measurement values and skin appearance impression score can have a high correlation it can.

Therefore, from the skin transparency (attenuation coefficient (μ _eff ), etc.) obtained by the present invention and color information (melanin amount, etc.), the impression of the appearance of the skin is obtained as an objective numerical value based on optical measurement. Can do. In addition, by obtaining a regression equation of skin transparency and color information and the impression score of skin appearance in advance, by measuring the transparency and color information for any subject, Objective evaluation values can be obtained.

Furthermore, by _performing multiple regression analysis of skin transparency measurement values (such as attenuation coefficient (μ _eff )) and color information measurement values (melanin content, etc.) It is possible to estimate the degree of contribution and to evaluate the influence of transparency on the skin texture (such as the presence or absence of spots, wrinkles, pores, blood vessels, etc.).

  Hereinafter, the present invention will be described in detail with reference to the drawings. In each figure, the same numerals indicate the same or equivalent components.

  1A and 1B show a measuring apparatus 1A according to an embodiment of the present invention, in which a skin as a sample S is irradiated with condensed light (FIG. 1A) and parallel light is irradiated. It is a typical block diagram of (FIG. 1B).

  This device 1A is a device that makes light incident on the skin as the sample S at an incident angle of 0 ° and detects the reflected light from the sample S at a light receiving angle (θ) of 45 °, and is white such as halogen or metal halide. A light source 2, a light guided from the white light source 2 is emitted from one end, an optical fiber (diameter 0.01 to 1 mm) 4 functioning as the point light source 3, and a condensing lens 5 that condenses the light emitted from the point light source 3. , A collimator lens 7 provided at the rear stage of the condenser lens 5, a diaphragm 6 provided between the condenser lens 5 and the collimator lens 7, and a condenser for condensing the parallel light formed by the collimator lens 7 on the sample S. An optical lens 8 and a digital camera 10 installed with a light receiving angle (θ) of 45 ° are provided. A diaphragm for adjusting the amount of light may be provided between the collimator lens 7 and the condenser lens 8 as needed (not shown). Here, the condensing lens 8 is detachable. Therefore, when the condenser lens 8 is removed from the optical path as shown in FIG. 1B, the sample S is irradiated with parallel light from the collimator lens 7.

In addition, the digital camera 10 of the apparatus 1A measures color information based on transparency measuring means for calculating an attenuation coefficient (μ _eff ) from an image detected by the digital camera 10 and an image detected by the digital camera 10. Color measuring means is connected (not shown).

As the transparency measuring means for calculating the attenuation coefficient (μ _eff ), for example, the luminance distribution in the radial direction of the image detected by the digital camera 10 is obtained as shown in FIG. 2, and if necessary, γ correction, dark current is obtained. Use a commercially available scientific graph analysis software for the brightness distribution obtained after correction, etc.

（式中、ｒ：動径距離（独立変数）
ｙ：輝度（従属変数）
ｋ：パラメータ ）
で非線形曲線にフィッティングし、減衰係数（μ_eff）を算出する演算機能を有するパーソナルコンピュータを使用することができる。

(Where r: radial distance (independent variable)
y: Luminance (dependent variable)
k: parameter)
Thus, it is possible to use a personal computer having a calculation function for fitting a nonlinear curve and calculating an attenuation coefficient (μ _eff ).

In addition, as a transparency measuring means for calculating the attenuation coefficient (μ _eff ), the tip of one or more optical fibers for light transmission / reception is brought into contact with the target object (skin), and measurement is performed by changing the light transmission / reception interval. I can give you something.

In addition, since the attenuation coefficient (μ _eff ) is a function of the absorption coefficient μ _a and the equivalent scattering coefficient μ _s ′, as an index of transparency, the absorption coefficient μ _a or equivalent scattering is used instead of the attenuation coefficient (μ _eff ). The coefficient μ _s ′ may be used. Note that the following relationship holds.

一方、色情報を計測する測色手段としては、公知の測色計を使用することができるが、皮膚の画像信号からＲＧＢ各成分の強度を検出できるものが好ましく、また、この測色手段には、メラニン量又はヘモグロビン量、あるいは必要に応じてこれらの双方を算出する色素量算出手段を接続することが好ましい。色素量算出手段としては、例えば、画像信号のＲＧＢ各成分の強度から独立成分分析によりこれらの成分ベクトルを求め、メラニン量の分布画像やヘモグロビン量の分布画像を出力するものを使用することができる。このような解析処理と画像処理の詳細は、Vol.16,No.9/September 1999/J.Opt.Soc.Am.A2169に記載されており、パーソナルコンピュータに、市販の画像解析ソフト（例えば、Adobe Photoshop）を搭載することに実現することができる。

On the other hand, as a colorimetric means for measuring color information, a known colorimeter can be used, but it is preferable to be able to detect the intensity of each RGB component from the skin image signal. Is preferably connected to a pigment amount calculating means for calculating the amount of melanin or the amount of hemoglobin, or if necessary, both of them. As the pigment amount calculation means, for example, a component that obtains these component vectors by independent component analysis from the intensity of each RGB component of the image signal and outputs a distribution image of the melanin amount or a distribution image of the hemoglobin amount can be used. . Details of such analysis processing and image processing are described in Vol. 16, No. 9 / September 1999 / J.Opt.Soc.Am.A2169, and commercially available image analysis software (for example, It can be realized by installing Adobe Photoshop.

  In addition, a gloss amount measuring unit may be provided as the color measuring unit. The gloss amount measuring means has a light receiving position in a mirror surface direction with respect to incident light (for example, in FIG. 1, light is incident on the sample S at an incident angle φ = 0 °, but this angle is used as the incident angle φ = −a. It can be configured by arranging a measuring instrument such as a camera in the direction of θ = a ° when the angle is changed to °, and using a polarization imaging technique.

  In this apparatus 1A, the distance from the point light source 3 to the irradiation surface of the sample S may be 50 to 5000 mm, and the distance from the irradiation surface of the sample S to the digital camera 10 may be assembled to about 60 to 6000 mm.

When measuring the attenuation coefficient (μ _eff ), the amount of melanin, and the amount of hemoglobin of the sample S with this apparatus 1A, first, the measurement chamber in which the apparatus is installed is a dark room, and the light is condensed on the sample S using the condenser lens 8. The reflected light is detected by irradiating light (FIG. 1A). Subsequently, the condenser lens 8 is removed and the sample S is irradiated with parallel light to detect the reflected light (FIG. 1B). Alternatively, first, the sample S is irradiated with parallel light to detect the reflected light (FIG. 1B), and then the condensed light is irradiated to detect the reflected light (FIG. 1A).

Then, an attenuation coefficient (μ _eff ), an absorption coefficient (μ _a ), or an equivalent scattering coefficient (μ _s ′) is calculated as a skin transparency parameter from the detection signal of the reflected light of the collected light, and the parallel light Color information is obtained from the detection signal of the reflected light, and the amount of melanin and the amount of hemoglobin are further calculated. As a result, the detection light is switched instantaneously, more specifically, at a shutter speed of 1/100 second to 20 seconds, and the attenuation coefficient (μ _eff ), which is a parameter of skin transparency, is _displayed in the color information. The corresponding melanin amount and hemoglobin amount can be obtained. Therefore, it is possible to align the psychological state of the subject that affects these during the measurement of transparency and the measurement of color information, and to have a high correlation between these and the impression score of the skin.

  That is, as shown in FIGS. 3A and 3B, when light is incident on the skins S1 and S2 from the optical fiber 11, generally, the skin S1 having a clean appearance looks light against the skin S2 having a poor appearance. Extrusion range (light penetration area) A is wide.

Therefore, when the skin appearance impression is scored in 7 stages, with the lowest being 1 and the highest being 7, there is a certain degree of correlation between the light penetration length (the reciprocal of the attenuation coefficient (μ _eff )) and the impression score. However, the correlation obtained by performing multiple regression analysis of the penetration length, melanin amount and hemoglobin amount and the impression score is improved, and in this case, the penetration length, melanin amount and hemoglobin amount are reduced. If the measurement is performed almost simultaneously by the method of the present invention, the correlation between these and the impression score can be further increased.

Therefore, with respect to the skin of a predetermined site of a large number of people, the melanin amount, hemoglobin amount, and attenuation coefficient (μ _eff ) are simultaneously measured by the method of the present invention, and an impression score of the skin appearance is obtained from a specialized panel. The amount of hemoglobin, the amount of hemoglobin and attenuation coefficient (μ _eff ) and the impression score are _subjected to multiple regression analysis to obtain a regression equation, while the melanin amount, hemoglobin amount and attenuation coefficient (μ _eff ) are similarly determined for any subject, When the skin impression score is calculated based on the regression equation, the impression score can be used as an objective evaluation value of the skin appearance impression of the subject.

  Although the present invention has been described based on the apparatus shown in FIGS. 1A and 1B, the present invention can take various forms.

  For example, the condensing lens 5 may be omitted between the point light source 3 and the collimator lens 7 as in the apparatus 1B shown in FIGS. 4A and 4B. In this case, it is preferable to use an achromatic lens as the collimator lens 7. 4A, a stop may be provided between the collimator lens 7 and the condenser lens 8 (not shown).

  Further, a pellicle half mirror 12 is provided at an angle of 45 ° with respect to the sample S between the condensing lens 8 and the sample S which are detachably provided, and the reflected light in the vertical direction is detected (light receiving angle 0 °). May be. The 0 ° incident 45 ° light reception without using the half mirror has a simple structure, but the use of the half mirror makes it possible to take an image in a state where the spread of the internal scattered light is concentric, so that the integration of the light amount is easy.

  Further, like the device 1C shown in FIGS. 5A and 5B, in the device 1B shown in FIGS. 4A and 4B, the lens system after the point light source 3 may be accommodated in the housing 13. This eliminates the need to use the device in a dark room during measurement. As the size of the housing 13, the vertical and horizontal lengths of the bottom surface can be about 30 mm to 500 mm, respectively, and the height can be about 20 to 200 mm.

  The housing 13 may be provided with a diffuser 14. Reference numeral 15 denotes a mirror.

Example 1
(1) Impression score The appearance impression of each measurement site is as follows by visual observation of 5 professional panels from a position about 1 m away, with 51 females aged 15 to 47 years old as subjects and 20 mm square of the cheek as a measurement site. The average of the evaluation values of five people was taken.
7: Excellent transparency and fairness 6: Clean 5: Slightly clean 4: Neither 4: Slightly clean 2: Not clean 1: Inferior in transparency, dark, not very clean

(2) Calculation of attenuation coefficient μ _eff Using the apparatus shown in FIGS. 4A and 4B, white light having a metal halide as a light source is focused on the measurement site in a dotted manner (diameter: about 100 μm) and reflected. A light image was taken with a digital camera (exposure time 5 seconds).

The luminance distribution in the radial direction from the center of the spot of the reflected light image is obtained, γ correction and dark current correction are performed, and the luminance distribution (attenuation curve) in the range where the radial distance is 1.5 to 10 mm is scientific. A nonlinear curve was fit by the following equation using a statistical graph / analysis software (ORIGIN, OriginLab) to determine the attenuation coefficient μ _eff .

（式中、ｒ：動径距離（独立変数）
ｙ：輝度（従属変数）
ｋ：パラメータ ）

(Where r: radial distance (independent variable)
y: Luminance (dependent variable)
k: parameter)

(3) Calculation of the amount of melanin and the amount of hemoglobin After taking the reflected light image of (2), remove the condenser lens 8, take the reflected light image of the measurement site, detect the intensity of each RGB component, and independently The amount of melanin and the amount of hemoglobin were calculated by component analysis.

(4) Multiple correlations between the attenuation coefficient μ _eff , the amount of melanin and hemoglobin, and the impression score
(4-1) The correlation coefficient between the impression score and the attenuation coefficient μ _eff was found to be 0.52. A correlation diagram in this case is shown in FIG.

(4-2) and the reflected light image to obtain the attenuation coefficient mu _eff, as 10 min detection interval of the reflected light image to obtain the amount of melanin and hemoglobin amount, attenuation coefficient mu _eff, to calculate the amount of melanin and hemoglobin amount, and these A multiple correlation with the impression score was taken. As a result, a correlation coefficient of 0.62 was obtained. A correlation diagram in this case is shown in FIG.

(4-3) The reflected light image for _{obtaining the} attenuation coefficient μ _eff and the reflected light image for obtaining the amount of melanin and hemoglobin are set almost simultaneously (10 seconds between both images), and the attenuation coefficient μ _eff , the amount of melanin and The amount of hemoglobin was calculated, and a multiple correlation was obtained between these and the impression score. As a result, a correlation coefficient of 0.71 was obtained. A correlation diagram in this case is shown in FIG.

From the results of (4-1) to (4-3), the reflected light image for determining the attenuation coefficient μ _eff and the reflected light image for determining the melanin amount and the hemoglobin amount are taken almost simultaneously, and the attenuation coefficient μ _eff , the melanin amount and By calculating the amount of hemoglobin, it is possible to minimize the influence of changes in the external environment and psychological environment of the skin on the skin blood flow and affecting them. Therefore, it can be seen that the correlation between the attenuation coefficient μ _eff , the melanin amount and the hemoglobin amount, and the impression score can be enhanced.

  According to the present invention, the impression of skin appearance can be expressed based on optical measurement values such as skin transparency and color information. Therefore, the present invention is useful for evaluating various beauty methods and cosmetics. Become.

It is a typical block diagram of the apparatus of the Example in the state which irradiates the condensed light to the sample. It is a typical block diagram of the apparatus of the Example of the state which irradiates a sample with parallel light. FIG. 4 is a relationship diagram between image brightness and radial distance. It is explanatory drawing of the oozing-out state of the light in skin with a beautiful external appearance impression. It is explanatory drawing of the oozing-out state of the light in the skin where an external appearance impression is inferior. It is a typical block diagram of the apparatus of the Example in the state which irradiates the condensed light to the sample. It is a typical block diagram of the apparatus of the Example of the state which irradiates a sample with parallel light. It is a typical block diagram of the apparatus of the Example in the state which irradiates the condensed light to the sample. It is a typical block diagram of the apparatus of the Example of the state which irradiates a sample with parallel light. FIG. 4 is a correlation diagram between an attenuation coefficient μ _eff and an impression score. Attenuation coefficient mu _eff when spaced measurement interval between the attenuation coefficient mu _eff and the amount of melanin and hemoglobin, a correlation diagram of the amount of melanin and hemoglobin amount, and the impression score. FIG. 6 is a correlation diagram of attenuation coefficient μ _eff , melanin amount and hemoglobin amount, and impression score measured almost simultaneously.

Explanation of symbols

1A, 1B, 1C Measuring device for optical properties of skin 2 White light source 3 Point light source 4 Optical fiber 5 Condensing lens 6 Aperture 7 Collimator lens 8 Condensing lens 10 Digital camera 11 Optical fiber 12 Pellicle half mirror 13 Housing 14 Diffuser 15 Mirror S, S1, S2 sample or skin

Claims (2)

( A) Irradiation means capable of continuously switching and irradiating condensed light and parallel light in a non-contact manner on the skin surface;
(B) Transparency measurement that detects the reflected light of the condensed light irradiated on the skin and calculates the attenuation coefficient (μ _eff ), absorption coefficient (μ _a ), or equivalent scattering coefficient (μ _{s ′} ) as an index of transparency means,
(C) a colorimetric means for detecting reflected light of parallel light irradiated on the skin and measuring color information ;
A pigment amount calculating means for calculating a melanin amount and a hemoglobin amount from the color information; and
Based on the regression equation of the calculated value of melanin, hemoglobin and transparency and the impression score of skin appearance, the impression score of the skin appearance of the subject is output from the calculated value of melanin, hemoglobin and transparency of any subject An apparatus for measuring the optical properties of the skin, comprising an arithmetic means for performing. (A) irradiating the skin surface in a non-contact manner by continuously switching and irradiating condensed light and parallel light;
(B) detecting reflected light of the condensed light irradiated on the skin, calculating an attenuation coefficient (μ _eff ), an absorption coefficient (μ _a ) or an equivalent scattering coefficient (μ _{s ′} ) as an index of transparency ;
(C) detecting the reflected light of the parallel light irradiated on the skin, measuring the color information ,
Calculate the amount of melanin and the amount of hemoglobin from the color information,
A regression equation of the calculated value of melanin amount, hemoglobin amount and transparency and the impression score of skin appearance is obtained, and based on the regression equation, from the calculated value of melanin amount, hemoglobin amount and transparency of any subject, the subject's A skin evaluation method for obtaining an impression score of skin appearance .

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