JP2019097687A - Skin observation method - Google Patents

Abstract

To provide a skin state observation method which enables a simultaneous and direct observation of an external side (a surface) and the inside of a skin surface layer, and a device used therefor.SOLUTION: A skin state observation method is a method for simultaneously observing states of a surface and the inside of a skin surface layer by using a microscope system including an imaging optical system for imaging an observation object in a wide view field and with a high resolution and an illumination system for emitting illumination light to the observation object and includes a process for observing by making light emitted from a directional light source obliquely incident on a surface of the observation object.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method and apparatus for observing the inside and outside of the skin surface.

  Human skin is composed of the epidermis, the dermis and its appendages (such as sweat glands). The epidermis is a tissue having a thickness of about 100 to 200 μm located in the outermost layer, and is composed of four layers of a basal layer, a spinous layer, a granular layer, and a stratum corneum in order from the inside of the body. The stratum corneum located at the top layer is the first line of defense against external stimuli and plays an important role in maintaining homeostasis of the living body. The stratum corneum is also a cosmetically important part. That is, the states and phenomena such as skin grooves, skin hills, textures or rough skin, pores, wrinkles, stains and sunburn are closely related to the disorder of the stratum corneum structure, the change of stratum corneum composition and the like. Therefore, to achieve healthy skin and beautiful skin, it is necessary to keep the stratum corneum in good condition.

  The stratum corneum is formed by keratinizing keratinocytes made in the basal layer, differentiating them into squamous stratum corneum cells through the spinous layer, granular layer. Since there are no capillaries in the epidermis (basal layer, spinous layer, granulosa layer, stratum corneum), oxygen and nutrients necessary for the metabolism and differentiation of keratinocytes are supplied from the dermis vascular system located below the surface of the skin. Specifically, capillaries in the papillary structure at the epidermal / dermal boundary and capillaries near the epidermis outside the papilla play a role in the final stage of supply.

  Blood does not always flow in these capillaries. Depending on the condition of the skin, the amount of blood flowing to the capillaries is considered to be controlled. For example, in regions where epidermal metabolism is active, it is considered that the volume of blood flowing to capillaries is large.

  Thus, the blood flow behavior in capillaries near the epidermis is 1) a factor directly affecting the metabolism and differentiation of keratinocytes in the epidermis, and 2) an factor indirectly contributing to the state of the stratum corneum, 3) Ultimately, it is considered to be a factor contributing to the realization of healthy and beautiful skin. Therefore, the skin condition of the stratum corneum surface and inner capillary blood vessels to assess the health condition of the skin, the cause of skin problems such as rough skin, and to evaluate substances and physical actions that improve the condition of the skin. It is ideal to simultaneously observe the existence and state of

In general, as an apparatus for observing the state of the skin surface, an imaging apparatus including an imaging optical system including an object to be observed, a lens and a camera, and an illumination system for irradiating the observation object with illumination light is used. For example, in Patent Document 1, a lens drive motor that switches observation magnification by reciprocating a part or all of the lens to a low magnification observation position and a high magnification observation position along an imaging optical axis direction, and a lens using the drive motor In conjunction with this, the large aperture low magnification observation aperture and the small aperture high magnification observation aperture are rotated to move on and off the imaging optical axis to adjust the aperture of the observation hole. There is disclosed an enlarged imaging apparatus having an aperture adjustment mechanism.
However, this device switches between low-magnification observation and high-magnification observation and does not observe the skin surface and the inside simultaneously. In addition, observation using this device is parallel polarization observation, that is, a condition in which polarized light is incident, only polarized light parallel to the incident is received on the detection side, and surface reflected light is selectively observed, or orthogonal polarization It consists of two observation conditions: observation, that is, polarized light is incident, the detection side receives only polarized light orthogonal to the incident, and the internally scattered light is selectively observed. Polarization switching is required to observe both. Further, in this apparatus, a technique of enlarging the center when expanding a wide visual field is adopted, and high resolution observation of the same place is difficult in a simple manner.

  Further, Patent Document 2 discloses a skin observation method characterized in that a plurality of LED illuminations are irradiated to a tip portion having a surface for diffusing light to indirectly illuminate the skin uniformly. In such a method, when observing the inside of the skin, the observation is performed by attaching a window material to the tip of the measurement probe and bringing the observation target into contact with the device to further reduce the reflected light from the surface. When observing the surface, conversely, without using the window material at the tip of the measurement probe, the object to be observed is measured without contact, and it is not possible to simultaneously observe the skin surface and the inside.

In addition, although the method of directly observing the blood flow state of the capillary in the surface layer of the skin using an optical microscope is known, in order to obtain the resolution capable of observing the blood flow of the capillary (diameter 10 to 50 μm) The field of view is usually only a few mm ² . Generally, the shape and distribution of capillaries are uneven, and it is not possible to accurately grasp the characteristics of the capillaries of the skin (the shape and distribution of capillaries) from the observation result of such a narrow region. . Therefore, a large number of observations are required to obtain a significant result, which places a heavy burden on the measurer and the subject.

Patent No. 4695930 gazette International Patent Publication No. 2015/075177

  The present invention relates to providing a method of observing a skin condition capable of directly observing the outside (surface) and the inside of the skin surface simultaneously and an apparatus used therefor.

That is, the present invention relates to the following 1) to 2).
1) Simultaneously observe the surface and inner surface conditions of the skin surface using a microscope system comprising an imaging optical system for imaging an observation object with a wide field of view and high resolution, and an illumination system for irradiating the observation object with illumination light A method of observing a skin condition, comprising the step of obliquely incident light emitted from a directional light source on the surface of an observation object and observing the light.
2) An apparatus used in the method of 1), wherein
A microscope system disposed on the opposite side to the subject via the subject placement unit, an image display unit for displaying image data, and an image processing unit for processing the image data, the microscope system comprising light emitted from the directional light source An apparatus for observing a skin condition, comprising an illumination system that obliquely strikes the surface of the observation target.

  According to the method of the present invention, the condition or phenomenon of the skin surface such as skin groove, skin hill, texture or rough skin, pore, wrinkle, etc., the presence of micro structure inside the skin such as capillaries, melanin granules (spots), etc. The states can be visualized simultaneously and directly and continuously. Thereby, the skin condition of the skin surface (for example, rough skin) and pigmentation generated inside the skin can be evaluated in association with the presence or state of capillaries. Therefore, by using the method and apparatus of the present invention, for example, substances that improve the condition of the skin, substances that affect the skin and evaluation of physical irritation, grasp of the health of the skin, rough skin It is possible to efficiently investigate the cause of skin problems such as

The whole block diagram of the observation apparatus of a skin condition. The whole block diagram of the observation apparatus of a skin condition. A: Appearance of oblique incidence ring illumination system, B: Appearance of oblique incidence illumination system, C: Definition of directivity angle and incidence angle Observation image of skin condition (Bottom: enlarged image of part in square frame). Schematic of a comparison apparatus. The observation image which shows evaluation of the skin thing before and behind processing (the left: before processing, the right: after processing, the lower stage: the enlarged image of the part in a square frame).

In the present invention, the observed skin condition includes the condition of the surface and the inside of the skin surface, and the condition of the skin surface is the condition of the skin surface such as skin groove, skin hill, texture or rough skin, pores, wrinkles, etc. Phenomena may be mentioned, and examples of the state inside the skin include the presence and state of micro structures inside the skin such as capillaries and melanin granules (spots). According to the present invention, it is possible to simultaneously and continuously visualize the state and phenomenon of the surface and the inside of the skin surface layer.
In the present invention, the body part to be the observation target of the condition of the skin surface is not particularly limited, and examples thereof include a hand, a foot, an arm, a leg, a body, a face and the like. Such a body part may be a body part after applying cosmetics or medicine.

The observation method of the skin condition of the present invention uses a microscope system including an imaging optical system for imaging an observation object with a wide field of view and high resolution, and an illumination system for irradiating the observation object with illumination light. It is a method to observe the surface and the internal state simultaneously. Hereinafter, the method of the present invention will be described by showing an example of an apparatus for carrying it (FIGS. 1 and 2), but the method of the present invention is not limited thereto.
FIG. 1 shows an aspect of an apparatus including a photographing table 2 provided with a subject placement unit 1 having an opening and a microscope system 3 disposed on the opposite side of the subject via the subject placement unit.
The subject placement unit 1 is a part of a photographing stand for placing a body part that is a subject, and the opening is filled with a transparent member if the subject can be observed by the microscope system 3 installed on the opposite side to the subject Although the member is not particularly limited, it is usually preferable to use a glass plate.
The shape and configuration of the photographing table 2 are not particularly limited as long as the photographing table 2 includes the subject placement unit 1 and the microscope system 3 can be disposed on the opposite side of the subject via the subject placement unit. For example, it may be a structure in which a flat plate including the subject placement part is supported by the support 6 (FIG. 1), the subject placement part is placed on one of the surfaces, and the microscope system is placed inside it. It may be a case (lens barrel 2a) having a shape of a rectangular solid, a cube, a cylinder or the like which can be connected and arranged (FIG. 2).
When using a structure in which the flat plate including the subject placement portion is supported by the support as the imaging table, the position of the microscope system 3 may be fixed, but the distance between the microscope system 3 and the subject and the observation visual field can be adjusted It is preferable that the position is adjustable by being connected to a position adjustment mechanism 7 such as a movable stage (XYZ axis stage) or a jack.

  The microscope system 3 includes an imaging optical system (lens 3a and camera 3c) for imaging an observation object with a wide field of view and high resolution, and an illumination system (light source) 3b for irradiating oblique incident light of a directional light source on the surface of the observation object The type is not limited as long as it is equipped with a stereomicroscope, a polarization microscope, a microscope or the like.

  As a lens used in the present invention, a lens with high resolution capable of observing a fine structure including the surface structure of the skin surface layer and the capillary inside is used. From this point of view, the horizontal resolution of the lens is 20 μm or less, and preferably 10 μm or less, more preferably 5 μm or less. The magnification of this lens is preferably not less than 0.25 times, more preferably not less than 0.5 times, and more preferably, in order to avoid that the apparatus becomes large and observation becomes difficult and to ensure a sufficient observation range. Is 0.75 times or more, and preferably 15 times or less.

The camera is not limited as long as it can capture an image (moving image or still image) with a wide field of view and high resolution of an observation image of a microscope, and a digital camera etc. employing an imaging device such as CCD or CMOS can be mentioned. The number of pixels of the imaging device is preferably 4 million or more, and more preferably 8 million or more, in order to obtain sufficient resolution.
Further, the size of the image pickup element is preferably 1⁄4 (3.6 × 2.7 mm) or more, and preferably, also in order to prevent the apparatus from becoming large and observation becomes difficult, and to obtain sufficient resolution. It is 4/3 type (17.3x13 mm) or less, more preferably type 1 (13.2 x 8.8 mm) or less, more preferably 2/3 type (8.8 x 6.6 mm) or less.

In the imaging optical system of the present invention, the visual field length is preferably 1 mm or more, more preferably 3 mm or more, still more preferably 6 mm or more, and preferably 12 mm or less, more preferably 11 mm or less, still more preferably 10 mm or less is there. Moreover, Preferably it is 1-12 mm, More preferably, it is 3-11 mm, More preferably, it is 6-10 mm.
The value [μm / mm] obtained by dividing the horizontal resolution by the field length is preferably 0.8 or less, more preferably 0.65 or less, and still more preferably 0.5 or less.

  Here, the “view length” is a diagonal of a square that constitutes the view. If it is a polygon, it is the length of the longest line segment among the diagonal lines and sides. When it is circular / elliptic, it shall be diameter / major axis. If it is indeterminate, it is the distance between the longest two points in the closed curve. Also, “horizontal resolution [μm]” refers to the resolution in the imaging plane, the shortest distance that can distinguish two points.

In the method of the present invention, observation of both the surface and the inside of the surface layer of the skin becomes possible by obliquely incident the light emitted from the directional light source on the surface of the observation target. At this time, it is assumed that the surface of the observation target faces the lens by being brought into contact with the subject placement unit.
Although visible light is generally used as the type of light source used as a directional light source, ultraviolet light having a wavelength of about 280 to 400 nm may be used, and near infrared light having a wavelength of about 800 to 1800 nm may be used. As the visible light, any light including wavelengths of 400 nm or more and less than 800 nm may be used, and in addition to white light, blue light, red light, green light and the like can be used, but visible light of different wavelengths is mixed It is preferred to use white light. For example, a white LED light source, a halogen lamp, etc. can be used.

  The directivity angle of the light emitted from the directional light source is preferably 15 degrees or more, more preferably 20 degrees or more, still more preferably 25 degrees or more, and preferably 60 degrees in view of observation of surface reflection from the skin. Or less, more preferably 50 or less, and even more preferably 40 or less. Moreover, preferably it is 15 to 60 degrees, More preferably, it is 25 to 50 degrees, More preferably, it is 30 to 40 degrees.

  The incident angle of oblique incidence to the surface of the observation object is preferably 40 degrees or more, more preferably 42.5 degrees or more, still more preferably 45 degrees or more, and preferably 75 degrees or more with respect to the optical axis of the lens. Or less, more preferably 65 or less, still more preferably 60 or less. Moreover, Preferably it is 40 to 75 degrees, More preferably, it is 42.5 to 65 degrees, More preferably, it is 45 to 60 degrees.

  In a preferred embodiment, the light irradiation is performed by setting the distance between the light source and the observation target to 10 to 60 mm, preferably 10 to 40 mm, more preferably 10 to 30 mm, and the directivity angle is 15 to 60 degrees, preferably Observation of light of 25 to 50 degrees, more preferably 30 to 40 degrees, at an incident angle of 40 to 75 degrees, preferably 42.5 to 65 degrees, more preferably 45 to 60 degrees with respect to the optical axis of the lens It is preferable to make the surface of the object obliquely incident, and the distance between the light source and the observation object is 10 to 30 mm, and the directivity angle is 30 to 40 ° incident 45 to 60 ° on the optical axis of the lens. It is further preferred that the light be obliquely incident on the surface to be observed at the corners.

  One aspect of an irradiation system for making light emitted from such a directional light source obliquely incident on the surface of the observation target (A: oblique incidence ring illumination system, B: oblique incidence illumination system), and directivity angle and incidence angle The definition is shown in FIG.

  Thus, microscopic images (moving and / or still images) of the surface and the inside of the skin surface layer are simultaneously imaged by the above-mentioned microscope system. The imaged image data is displayed by the image display unit 5 such as a television monitor, and the state of the skin surface (skin groove, skin hill, texture or rough skin, pores, wrinkles, etc.) by the person, the state inside the skin (capillary, melanin) Granules (spots and the like) are observed, and further, the image processing unit 4 (computer) is used to analyze and analyze the outer and inner states of the skin in more detail. The state of capillaries includes the number of capillaries, distribution (uniform and nonuniform), shape, blood flow velocity and the like.

  Taking advantage of the high resolution and wide field of view observation that is the feature of the above microscope system, the skin microstructure such as texture, pores, sweat glands, stains and capillaries are clearly imaged in a wide field of view of 1 mm or more can do. In addition, by enlarging and displaying on the image display unit, a minute structure can be observed more clearly. By determining an arbitrary feature point from the image information and utilizing it, the same field of view can be easily identified at the time of remeasurement such as daily observation, and fixed point observation becomes possible.

Regarding the embodiment described above, the following aspects are further disclosed in the present invention.
<1> Using a microscope system having an imaging optical system for imaging an observation object with a wide field of view and high resolution, and an illumination system for irradiating illumination light to the observation object, the surface surface and the internal state are simultaneously processed A method of observing a skin condition, comprising observing the light emitted from the directional light source obliquely on the surface of the observation target and observing the light.
<2> The distance between the light source and the observation target is 10 to 60 mm, and light with a directivity angle of 15 to 60 ° is obliquely incident on the surface of the observation target at an incident angle of 40 to 75 ° with respect to the optical axis of the lens , <1> way.
<3> The observation of the skin condition simultaneously observes the condition of the skin surface selected from skin grooves, skin hills, texture or rough skin, pores and wrinkles, and the condition inside the skin selected from capillaries and melanin granules, <1 > Or <2> method.
The method in any one of <1>-<3> which observes the skin condition after <4> cosmetics are applied.
The method in any one of <1>-<4> which observes the same location using the feature point on <5> skin.
The method in any one of <1>-<5> using the imaging optical system whose <6> view length is 1-12 mm.
The method in any one of <1>-<6> using the imaging optical system from which the value which divided | segmented <7> horizontal resolution by the length of the visual field becomes 0.8 [micrometer / mm] or less.
The method in any one of <1>-<7> whose pixel count of the image pick-up element for <8> imaging is 4 million pixels or more, preferably 8 million pixels or more.
The size of the imaging device for <9> imaging is preferably 1⁄4 type (3.6 × 2.7 mm) or more, and preferably 4/3 type (17.3 × 13 mm) or less, more preferably type 1 (13 .2 x 8.8 mm) or less, more preferably 2/3 type (8.8 x 6.6 mm) or less, the method of any one of <1> to <8>.
The magnification of the lens for <10> imaging is preferably 0.25 times or more, more preferably 0.5 times or more, more preferably 0.75 times or more, and preferably 15 times or less. The method in any one of <1>-<9>.
It is an apparatus used for the method in any one of <11><1>-<10>,
An imaging table provided with a subject placement unit; a microscope system disposed on the opposite side of the subject via the subject placement unit; an image display unit for displaying image data; and an image processing unit for processing the image data; An observation apparatus for a skin condition, wherein the microscope system has an illumination system that obliquely enters the light emitted from the directional light source on the surface of the observation target.

Example 1 (see FIG. 4)
With a CMOS camera (BU 1203, 12 million pixels, 1 / 1.7 type sensor, Toshiba Teli) with a working distance of 68 mm and a 1x magnification lens (VS-TCT1-65 / S, VS Optics) upward Connected. The camera can be connected to an XYZ axis stage that combines an XY axis stage (TSD-602C, Sigma Light Co., Ltd.) and a Z axis stage (B33-60KGA, Suruga Seiki Co., Ltd.), and the distance to the skin surface and the field of view can be adjusted And A light source unit (ring capable of oblique incidence at an incident angle of 60 ° with respect to the lens optical axis) at a 45 ° directivity angle so that the distance to the observation target is 45 mm above the optical axis (Z axis) of the lens White LED light source (OPDR-LA 74-48W-2, manufactured by OPTEX FA, Inc., see FIG. 3A). The subject's inner forearm was placed on the subject placement portion (plate with a 15 mm opening) of the imaging stand so that the skin surface was positioned at the focal position of the lens, and shooting was performed. The results are shown in FIG. 4A. The upper figure shows the entire field of view, and the lower figure is an enlarged view of the solid line part surrounded by a square in the upper figure.
From FIG. 4A, it is observed that the shape of texture is observed as information on the skin surface, and sweat glands and capillaries are observed as information on the inside of the skin. Thus, the surface and internal microstructures can be observed simultaneously.

Examples 2 to 5 (see FIG. 4)
With a CMOS camera (BU 1203, 12 million pixels, 1 / 1.7 type sensor, Toshiba Teli) with a working distance of 68 mm and a 1x magnification lens (VS-TCT1-65 / S, VS Optics) upward Connected. A lens barrel having an opening of 1212 mm at the tip of the lens and four illumination inserts at the wall was attached. A predetermined directivity angle adjusted so as to have a predetermined incident angle at the illumination plug (Example 2: Incident angle 60 °, directivity angle 30 °, Example 3: Incident angle 45 °, directivity angle 15 °, Example 4: A 3 mm shell-shaped white LED (manufactured by OptoSupply) having an incident angle of 45 °, a directional angle of 30 °, Example 5: an incident angle of 45 °, a directional angle of 30 ° was attached (see FIG. 3B). The subject's forearm inner part was placed on the opening of the lens barrel and photographed. The results are shown in Figures 4B-E.
From FIGS. 4B, 4C, 4D, and 4E, it is observed that the texture of the texture is observed as the information on the skin surface (the upper part of each figure), and the capillary is observed as the information inside the skin (the lower part of each figure). Thus, the surface and internal microstructures can be observed simultaneously.

Comparative Example 1
With a CMOS camera (BU 1203, 12 million pixels, 1 / 1.7 type sensor, Toshiba Teli) with a working distance of 68 mm and a 1x magnification lens (VS-TCT1-65 / S, VS Optics) upward Connected. The camera can be connected to an XYZ axis stage that combines an XY axis stage (TSD-602C, Sigma Light Co., Ltd.) and a Z axis stage (B33-60KGA, Suruga Seiki Co., Ltd.), and the distance to the skin surface and the field of view can be adjusted And Diffuse illumination (HPD 2-150 SW, CCS Inc.) with a white LED light source having a dome coated with a substance that diffuses light inside was disposed at the tip of the lens. The subject's inner forearm was placed on the subject placement portion (plate with a 15 mm opening) of the imaging stand so that the skin surface was positioned at the focal position of the lens, and shooting was performed (see FIG. 5). The results are shown in FIG. 4F.
As shown in FIG. 4F, the texture of the texture can be observed as the information on the skin surface (upper), but the structure such as capillaries is not seen and the information inside the skin can not be observed (lower).

Example 6 Evaluation of rough skin (texture disorder, inflammation) at the same site The rough skin was induced by the cup shake method. With the 3030 mm cup in close contact with the skin on the inner side of the subject's forearm, pour 10 mL of 3 wt% sodium dodecyl sulfate aqueous solution into the cup and allow it to contact the skin for 15 minutes. Lightly wiped the skin and allowed to dry naturally for another 15 minutes. Using the same apparatus as in Example 1, the skin before the skin processing and the skin after the skin processing were placed on the subject placement portion (a plate having a 15 mm opening) so that the skin surface was positioned at the focal position of the lens. The subject's inner forearm was placed on the) and photographed. The results are shown in FIG.
From FIG. 6, it is clearly observed that the brightness of the contour becomes high (white) due to the texture being disturbed, the fine structure being increased after the skin treatment and the light reflection being increased, as compared with the skin treatment before. In addition, it was also clearly observed that the low-brightness (dark) observed capillaries had lower brightness as the blood flow increased after the rough skin treatment.

DESCRIPTION OF SYMBOLS 1 object arrangement | positioning part 2 imaging stand 2a lens barrel 3 microscope system 3a lens 3b light source 3c camera 4 image processing part 5 image display part 6 support 7 position adjustment mechanism

Claims (8)

  A method of simultaneously observing the surface and the inner surface of a skin surface using a microscope system having an imaging optical system for imaging an observation object with a wide field of view and high resolution and an illumination system for irradiating illumination light to the observation object A method of observing a skin condition, comprising the steps of oblique incidence of light emitted from a directional light source on a surface of an observation target and observation.   The distance between the light source and the observation target is 10 to 60 mm, and light having a directivity angle of 15 to 60 ° is obliquely incident on the surface of the observation target at an incident angle of 40 to 75 ° with respect to the optical axis of the lens. Method 1 described.   The observation of the skin condition simultaneously observes the condition of the skin surface selected from skin grooves, skin crests, texture or rough skin, pores and wrinkles, and the condition inside the skin selected from capillaries and melanin granules. Method described.   The method according to any one of claims 1 to 3, wherein the skin condition after applying the cosmetic is observed.   The method according to any one of claims 1 to 4, wherein observation at the same place is performed using feature points on the skin.   The method according to any one of claims 1 to 5, wherein an imaging optical system having a field length of 1 to 12 mm is used.   The method according to any one of claims 1 to 6, wherein an imaging optical system in which a value obtained by dividing the horizontal resolution by the length of the field of view is equal to or less than 0.8 [μm / mm] is used. An apparatus for use in the method according to any one of claims 1 to 7, comprising
A microscope system disposed on the opposite side to the subject via the subject placement unit, an image display unit for displaying image data, and an image processing unit for processing the image data, the microscope system comprising light emitted from the directional light source An apparatus for observing a skin condition, comprising an illumination system that obliquely strikes the surface of the observation target.