Skin viscoelasticity measuring apparatus and skin viscoelasticity measuring method

Abstract

A skin viscoelasticity measuring device according to one embodiment includes a contact part, a moving part that moves the contact part, a measuring part that measures a force applied and a displacement or a displacement applied and a force applied during the process of the contact part pressing into the skin, and a control part that simulates the viscoelasticity model of the skin as a skin viscoelasticity model in which two systems, each consisting of one elastic body and one elastic body and one buffer body, are connected in parallel, and calculates the viscoelasticity characteristics of the skin based on the measured force or displacement.

Description

Technology Field

[0001] The present invention relates to a skin viscoelasticity measuring device and a skin viscoelasticity measuring method. Background Technology

[0002] The term “cosmetics” refers to products used on the human body by applying, rubbing, spraying, or similar methods to cleanse and beautify the body, enhance attractiveness, brighten the appearance, or maintain or improve the health of the skin and hair, and which have a minor effect on the human body; they are classified into general cosmetics and functional cosmetics according to their function.

[0003] Functional cosmetics include products that help whiten the skin, improve wrinkles, help tan the skin evenly or protect it from ultraviolet rays, help change or remove hair color or provide nourishment, and help prevent or improve dryness, cracking, hair loss, and keratinization caused by weakened skin or hair function. Among these, functional cosmetics that help improve wrinkles can help restore elasticity to aging skin.

[0004] Skin elasticity can vary depending on various factors such as the user's age, lifestyle, and skin characteristics, so appropriate cosmetics should be used considering the individual's skin elasticity. However, conventionally, skin viscoelasticity has been measured by conducting stress relaxation tests by simulating the skin as an overly simplistic viscoelastic material. Consequently, there is a problem where the measured viscoelasticity differs from the user's actual skin viscoelasticity. Prior art literature

[0005] Korean Registered Patent Publication No. 10-1229238 The problem to be solved

[0006] A skin viscoelasticity measuring device and a skin viscoelasticity measuring method according to one embodiment provide a skin viscoelasticity measuring device and a skin viscoelasticity measuring method that more precisely mimic the viscoelastic characteristics of the skin and can accurately measure the viscoelasticity of the skin even with a simple configuration. means of solving the problem

[0007] A skin viscoelasticity measuring device according to one embodiment includes a contact part, a measuring part that measures a force applied and a displacement resulting therefrom during the process of the contact part pressing into the skin or a displacement and a force applied and a displacement resulting therefrom during the process of the contact part pressing into the skin, and a control part that simulates the viscoelasticity model of the skin as a skin viscoelasticity model in which two systems, each comprising at least one elastic body system and at least one elastic body and one buffer body, are connected in parallel, and calculates the viscoelasticity characteristics of the skin based on the measured force or displacement.

[0008] In a skin viscoelasticity measuring device according to one embodiment, the control unit fits the measured force or displacement over time using the following formula to E ∞ , E1, E2, τ1 and τ2 can be calculated.

[0009]

[0010] Here, F is the measured force, R is the radius of the part where the contact indents the skin, ν is the Poisson's ratio of the skin, d is the depth of indentation of the contact into the skin, E ∞ τ1 represents the elastic modulus of a system containing one elastic body, E1 and E2 represent the respective elastic modulus of two systems containing one elastic and one buffer, and τ1 and τ2 represent the respective damping modulus of two systems containing one elastic and one buffer.

[0011] In a skin viscoelasticity measuring device according to one embodiment, the measuring unit includes a load cell that measures the force with which the contact part presses against the skin, and the control unit causes the contact part to press against the skin by a preset displacement while in contact with the skin but without pressing against the skin, and can calculate the viscoelasticity characteristics of the skin viscoelasticity model based on the force detected by the load cell according to the displacement of the contact part.

[0012] A skin viscoelasticity measuring device according to one embodiment may further include a moving part that receives a control signal from the control part and contacts the contact part with the skin or separates it from the skin.

[0013] In a skin viscoelasticity measuring device according to one embodiment, the skin viscoelasticity measuring device further comprises a housing and a support member disposed on one side of the housing and supporting a user's face, the contact member is disposed to face the user's face seated on the support member and includes a probe at its tip, the moving member moves the contact member in three different directions to indent the skin to a preset maximum indentation depth, and the measuring member is disposed on the contact member and can measure the force applied as the contact member indents the skin.

[0014] In a skin viscoelasticity measuring device according to one embodiment, the skin viscoelasticity measuring device further comprises a housing, the contact part contacts the skin through an opening formed in the housing, and includes a probe made of a metal material and a support part made of an elastic material connected to the probe, and the moving part is an electromagnet controlled by power applied by the control part, so that when power is supplied, the support part is deformed in advance by a preset force, and when power supplied from the control part is cut off, the support part is released so that the elastic body presses into the skin, and the measuring part can measure the displacement between the initial state of the contact part and the state pressed into the skin.

[0015] In a skin viscoelasticity measuring device according to one embodiment, the support member is a spring with one end connected to the housing and the other end connected to the probe, and the control member can supply power to the moving member in an initial state to pull the probe upward, and then cut off the power supplied to the moving member so that the support member returns to its original position and presses into the skin.

[0016] In a skin viscoelasticity measuring device according to one embodiment, the support member is a metal member with one end connected to the housing and the other end connected to the probe, and the control member can supply power to the moving member in an initial state to bend the support member upward, and then cut off the power supplied to the moving member so that the support member returns to its original position and presses into the skin.

[0017] In a skin viscoelasticity measuring device according to one embodiment, the support member is made of a deformable material whose edge is supported on the inner surface of the housing, and the probe is positioned in the center, and the control member can apply voltage to the moving member to press the probe toward the skin.

[0018] In a skin viscoelasticity measuring device according to one embodiment, the housing may be placed on the skin.

[0019] A method for measuring skin viscoelasticity according to one embodiment includes the steps of: contacting a probe with the skin; moving the probe by a preset displacement or moving it with a preset force to indent the skin; measuring the force or displacement resulting from the probe indenting the skin; and fitting the measured force or displacement to a skin viscoelasticity model in which a system comprising at least one elastic body and two systems comprising at least one elastic body and one buffer body are connected in parallel to calculate the viscoelasticity characteristics of the skin.

[0020] Other aspects, features, and advantages other than those described above will become clear from the specific details, claims, and drawings for implementing the invention below. Effects of the invention

[0021] A skin viscoelasticity measuring device and a skin viscoelasticity measuring method according to one embodiment can quantify the viscoelasticity of the skin using a skin viscoelasticity model that can more precisely simulate the viscoelasticity of the skin.

[0022] A skin viscoelasticity measuring device and a skin viscoelasticity measuring method according to one embodiment can easily measure the viscoelasticity characteristics of the skin by measuring the force or displacement according to the displacement or force applied to the probe. Brief explanation of the drawing

[0023] Figure 1 schematically shows a state in which a skin viscoelasticity measuring device according to one embodiment is mounted on a user's skin. FIG. 2 schematically illustrates a skin viscoelasticity measuring device according to one embodiment. Figure 3 schematically shows the structure of the human skin. FIG. 4 shows a skin viscoelasticity model according to one embodiment. Figure 5 shows the results of a stress relaxation test on a skin viscoelastic model according to one embodiment. FIG. 6 shows a skin viscoelasticity measuring device according to another embodiment. FIG. 7 illustrates the operation of a skin viscoelasticity measuring device according to another embodiment. FIG. 8 shows a skin viscoelasticity measuring device according to another embodiment. FIGS. 9 and 10 illustrate the operation of a skin viscoelasticity measuring device according to another embodiment. FIGS. 11 and 12 illustrate the operation of a skin viscoelasticity measuring device according to another embodiment. FIGS. 13 and 14 illustrate the operation of a skin viscoelasticity measuring device according to another embodiment. FIG. 15 shows the measurement results of a skin viscoelasticity measuring device according to one embodiment. Figures 16 and 17 show the results of skin viscoelasticity measurements. Specific details for implementing the invention

[0024] The present invention includes various embodiments and modifications, and specific embodiments are shown in the drawings and described below in the description of the invention. The present invention is not limited to the following embodiments and includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0025] In the following embodiments, singular expressions include plural expressions unless the context clearly indicates otherwise. In the following embodiments, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0026] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0027] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0028] In this specification, "or" includes not only cases where components "A" and "B" are included alternatively, but also cases where both components "A" and "B" are included, unless explicitly specified otherwise.

[0029] FIG. 1 schematically shows a state in which a skin viscoelasticity measuring device (10) according to one embodiment is mounted on a user's skin, FIG. 2 schematically shows a skin viscoelasticity measuring device (10) according to one embodiment, FIG. 3 schematically shows the structure of human skin, FIG. 4 shows a skin viscoelasticity model according to one embodiment, and FIG. 5 shows the stress relief test results of the skin viscoelasticity model according to one embodiment.

[0030] A skin viscoelasticity measuring device (10) according to one embodiment can be used to measure the viscoelasticity of a user's skin. Viscoelasticity is a characteristic of a material that exhibits both viscous and elastic properties when deformation occurs, and human skin is a typical viscoelastic material that possesses both viscosity and elasticity.

[0031] As shown in Figure 3, the human skin (dermis) is composed of fibrous proteins and an extracellular matrix. The fibrous proteins are mainly composed of collagen and elastin and affect the elasticity of the skin. The matrix is ​​mainly composed of hyaluronic acid and proteoglycans and affects the elasticity of the skin.

[0032] As such, human skin possesses both elasticity and viscosity, so it takes some time for deformation to occur after an external force is applied, and conversely, it takes some time for it to be restored even after the external force is relieved. Therefore, all conventional studies that measured the viscoelasticity of the skin by considering it as a simple linear elastic model were unable to accurately measure the actual viscoelasticity of the skin. Furthermore, as mentioned earlier, the fibrous proteins of the skin include both collagen and elastin, and since collagen has a much higher elastic modulus value than elastin (Young's modulus of collagen: 1 to 10 GPa, Young's modulus of elastin: 100 to 350 kPa), all conventional studies that treated them as the same elastic body and buffer (damper or dashpot) in viscoelastic models were also unable to accurately measure the actual viscoelasticity of the skin.

[0033] In order to solve these problems, the skin viscoelasticity measuring device (10) and the skin viscoelasticity measuring method according to one embodiment newly modeled a skin viscoelasticity model capable of precisely simulating all of the skin viscoelasticity of the human body. As shown in FIG. 4, the skin viscoelasticity measuring device (10) and the skin viscoelasticity measuring method model the viscoelasticity of the skin with at least one elastic body (spring; E ∞ A viscoelastic model was simulated by a system including ) and two systems including at least one elastic body (E1, E2) and one buffer (damper or dashpot; η1, η2) connected in parallel. In one embodiment, the skin viscoelasticity measuring device (10) and the skin viscoelasticity measuring method simulated the viscoelastic model of the skin by a system consisting of one elastic body and two systems consisting of one elastic body and one buffer, respectively, connected in parallel.

[0034] And as shown in Fig. 5, a stress relaxation test was performed on the corresponding skin viscoelastic model (hereinafter also referred to as the “skin viscoelastic model”) to derive a mathematical equation of force over time for the skin viscoelastic model. The equation comprises two exponential damping functions (e) depending on the interval -t / τ1 , e -t / τ2 It can be represented as ), and is expressed as follows.

[0035]

[0036] Here, F represents force, R represents the radius of the probe used in the stress relaxation test, d represents the depth of the probe's indentation into the skin, ν represents the Poisson ratio of the skin, τ represents the time constant, and t represents time. E ∞ τ1 represents the elastic modulus of a system containing one elastic body, E1 and E2 represent the respective elastic modulus of two systems containing one elastic and one buffer, and τ1 and τ2 represent the respective damping coefficients of two systems containing one elastic and one buffer. In addition, since the time constant τ=η / E is satisfied, both the elastic modulus and the viscosity coefficient of the skin viscoelasticity model can be calculated from the above mathematical formula. Through this, the skin viscoelasticity measuring device (10) and the skin viscoelasticity measuring method according to one embodiment can quantify the viscoelasticity of human skin and, based on the quantified viscoelasticity, identify and diagnose the amount of collagen and elastin, the state of fibrous proteins and substrates, etc.

[0037] In this specification, the Poisson ratio ν of the skin can be calculated as 0.48 by referring to GJ Gerling and GW Thomas, "The effect of fingertip microstructures on tactile edge perception," First Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, IEEE 63-72 (2005). Alternatively, according to other research results regarding the Poisson ratio of the skin, the skin viscoelasticity measuring device (10) and the skin viscoelasticity measuring method according to one embodiment may measure the viscoelasticity of the skin by selecting a Poisson ratio of 0.4 or more and 0.5 or less, or 0.3 or more and 0.6 or less, or 0.2 or more and 0.7 or less.

[0038] In one embodiment, the skin viscoelasticity measuring device (10) may include a contact part (100), a moving part (200), a measuring part (300), and a control part (400).

[0039] The contact portion (100) contacts the user's skin and presses the skin. The contact portion (100) can be moved by the moving portion (200) to press the user's skin with a preset displacement or preset force. In one embodiment, the contact portion (100) may include a probe that directly contacts the skin at a tip facing the user's skin. The probe has a blunt tip shape, and in one embodiment, it may be hemispherical.

[0040] The moving unit (200) moves the contact unit (100) in one or more directions to press the contact unit (100) against the user's skin. The moving unit (200) includes one or more motors, and the motors may be one or more of linear motors, step motors, and servo motors. In one embodiment, the moving unit (200) may move the contact unit (100) in the X-axis, Y-axis, and Z-axis directions, respectively, to make contact with the user's skin. If necessary, the moving unit (200) may rotate the contact unit (100) around the X-axis, Y-axis, and Z-axis. The moving unit (200) receives a signal from the control unit (400) and may move the contact unit (100) by a preset displacement or press the contact unit (100) against the skin with a preset force.

[0041] The measuring unit (300) measures the force applied and the resulting displacement during the process of the contact unit (100) pressing into the skin, or the displacement and the resulting force applied during the process of the contact unit (100) pressing into the skin, and transmits it to the control unit (400). In one embodiment, the measuring unit (300) is a load cell capable of measuring in real time the force corresponding to the displacement when the contact unit (100) moves from the displacement at the time of contact with the skin to the maximum pressing depth, which is a preset displacement, and transmits the measured force data to the control unit (400). In one embodiment, the measuring unit (300) is a displacement sensor capable of measuring in real time the displacement of the contact unit (100) when the contact unit (100) presses into the skin with a preset force, and transmits the measured displacement data to the control unit (400).

[0042] The control unit (400) is connected to the contact unit (100), the moving unit (200), and the measuring unit (300) via wired or wireless means and controls the contact unit (100), the moving unit (200), and the measuring unit (300). In one embodiment, the control unit (400) controls the moving unit (200) to move the contact unit (100) to a preset indentation depth and can receive data regarding the force measured in real time from the measuring unit (300). Furthermore, the control unit (400) can calculate the elastic modulus and the time constant (viscosity coefficient) of the skin viscoelasticity model from a mathematical formula using the known radius of the probe, Poisson's ratio, the maximum indentation depth of the contact unit (100), and the force measured by the measuring unit (300). In one embodiment, the control unit (400) controls the moving unit (200) to cause the contact unit (100) to press the skin with a preset force, and can receive data regarding displacement measured in real time from the measuring unit (300). The control unit (400) can fit the measured force or displacement over time to the following equation regarding the skin viscoelasticity model.

[0043]

[0044] And the control unit (400) can calculate the elastic modulus and the time constant (viscosity coefficient) of the skin viscoelastic model from a mathematical formula using the radius of the probe known in advance, the Poisson ratio, the indentation force (restoring force) of the contact unit (100), and the displacement measured by the measuring unit (300).

[0045] In one embodiment, the control unit (400) can calculate the elastic modulus and time constant (viscosity coefficient) of the skin viscoelastic model by fitting the force or displacement measured by the measurement unit (300) over time to the mathematical formula.

[0046] The control unit (400) may be disposed separately from the contact unit (100), the moving unit (200), and the measuring unit (300), or may be disposed together with the contact unit (100), the moving unit (200), and the measuring unit (300). In one embodiment, the skin viscoelasticity measuring device (10) may be formed as a single component, and the contact unit (100), the moving unit (200), the measuring unit (300), and the control unit (400) may be disposed therein. Alternatively, the control unit (400) may be spaced apart from the contact unit (100), the moving unit (200), and the measuring unit (300) and connected to the contact unit (100), the moving unit (200), and the measuring unit (300) via wired or wireless connections.

[0047] The control unit (400) may include a communication device (410), a storage device (420), a computation device (430), and an input / output device (440).

[0048] The communication device (410) is a device for communicating with the contact part (100), the moving part (200), the measuring part (300) and an external device, and the control part (400) can receive data from the measuring part (300) through the communication device (410) and transmit control signals to the contact part (100), the moving part (200) and the measuring part (300).

[0049] The storage device (420) is a computer-readable recording medium and includes non-perishable mass recording devices such as RAM, ROM, and disk drives, and may store an operating system and at least one program code. These software components may be loaded from a computer-readable recording medium separate from the storage device (420) using a drive mechanism. This separate computer-readable recording medium may include computer-readable recording media such as floppy drives, disks, tapes, DVD / CD-ROM drives, and memory cards. Software components may also be loaded into the storage device (420) via a communication device (410) rather than a computer-readable recording medium. In one embodiment, at least one program may be loaded into the storage device (420) based on a program or application installed by files provided over a network by developers or a file distribution system that distributes installation files for applications. In one embodiment, the storage device (420) may pre-store data regarding the maximum indentation depth of the contact portion (100), the probe diameter of the contact portion (100), the Poisson ratio, and the mathematical formula.

[0050] The arithmetic unit (430) is implemented with one or more processors and can process instructions of a computer program by performing basic arithmetic, logic, and input / output operations. In one embodiment, the arithmetic unit (430) can calculate the elastic modulus and the time constant (viscosity coefficient) of the skin viscoelasticity model based on data measured by the measuring unit (300) and data stored in the storage unit (420).

[0051] The input / output device (440) can receive user input and output the current state of the skin viscoelasticity measuring device (10). In one embodiment, the input / output device (440) may include devices capable of receiving various forms of user input, such as a keyboard, physical buttons, a touch screen, a camera, or a microphone, and devices capable of delivering various forms of output, such as a display panel or a speaker.

[0052] In one embodiment, the control unit (400) may be implemented as a user terminal or server, such as a desktop, laptop, smartphone, or tablet. In this case, the contact unit (100), the movement unit (200), and the measurement unit (300) are provided outside the control unit (400), and the control unit (400) can transmit and receive data with the contact unit (100), the movement unit (200), and the measurement unit (300) through a communication device (410). Additionally, the skin viscoelasticity measurement method may be implemented in the control unit (400) in the form of an application or program.

[0053] In FIG. 1, the area indicated by the dotted line on the user's face may represent the area of ​​skin where the skin viscoelasticity measuring device (10) intends to measure viscoelasticity. In one embodiment, the dotted line area shown in FIG. 1 may be the area where the contact part (100) of the skin viscoelasticity measuring device (10) comes into contact with the skin. Although FIG. 1 shows the dotted line area near the user's forehead or cheek, the area where the skin viscoelasticity measuring device (10) measures viscoelasticity may include other parts of the body such as the back, shoulders, arms, hands, and legs, in addition to other parts of the face.

[0054] The operation of the skin viscoelasticity measuring device (10) is described as follows.

[0055] First, the contact portion (100) is brought into contact with the skin of the user to be measured. At this time, the contact portion (100) does not press against the skin and can maintain a state where the tip is in contact with the skin. In one embodiment, the measuring portion (300) measures the force applied to the contact portion (100) or the displacement of the contact portion (100) and transmits it to the control portion (400). The control portion (400) can determine whether the contact portion (100) is in contact with the skin or is in a state of pressing against the skin based on the received force or displacement data. If the contact portion (100) is not in contact with the skin or is in a state of pressing against the skin, the control portion (400) can send a signal to the moving portion (200) to adjust the position of the contact portion (100).

[0056] Next, the control unit (400) sends a signal to the moving unit (200) to cause the contact unit (100) to press into the skin. The moving unit (200) moves the contact unit (100) to a predetermined maximum indentation depth, and the measuring unit (300) can measure the force during this process. Alternatively, the moving unit (200) moves the contact unit (100) with a predetermined force, and the measuring unit (300) can measure the displacement during this process. The control unit (400) calculates the viscoelastic properties of the skin based on data regarding the force or displacement measured by the measuring unit (300). In one embodiment, the computing device (430) of the control unit (400) receives information regarding the maximum indentation depth or indentation force of the contact unit (100), the probe diameter of the contact unit (100), the Poisson ratio of the skin, and the above mathematical formula regarding the viscoelastic model from the storage device (420), and fits the above mathematical formula to the measured force or displacement. Additionally, the computing device (430) calculates the elastic modulus and time constant (viscosity coefficient) of the skin viscoelastic model based on the fitting result, and the input / output device (440) transmits the fitting result and the elastic modulus and time constant (viscosity coefficient) of the skin viscoelastic model to the user through a display, etc.

[0057] Through such a configuration, a skin viscoelasticity measuring device (10) according to one embodiment includes a contact part (100), a moving part (200) that moves the contact part (100) to press into the skin, and a measuring part (300) that measures the force applied and the resulting displacement during the process of the contact part (100) pressing into the skin, or the displacement applied and the resulting force applied during the process of the contact part pressing into the skin. A control part (400) can simulate the viscoelasticity model of the skin as a viscoelasticity model in which a system consisting of one elastic body and two systems consisting of one elastic body and one buffer body are connected in parallel, and can calculate the viscoelasticity characteristics of the skin based on the measured force or displacement.

[0058] FIG. 6 shows a skin viscoelasticity measuring device (10A) according to another embodiment, and FIG. 7 shows the operation of a skin viscoelasticity measuring device (10A) according to another embodiment.

[0059] The skin viscoelasticity measuring device (10A) according to the present embodiment differs in some configurations of the contact part (100A), moving part (200A), measuring part (300A), and control part (400A) compared to the skin viscoelasticity measuring device (10) described above, and may further include a housing (11A), a support (13A), a guide (15A), and a seating groove (17A). For convenience of explanation, the skin viscoelasticity measuring device (10A) is described below focusing on configurations different from the skin viscoelasticity measuring device (10), and descriptions of identical configurations may not be repeated.

[0060] Referring to FIGS. 6 and 7, the skin viscoelasticity measuring device (10A) can measure the viscoelasticity of the skin while directly supporting the user's body. In one embodiment, the skin viscoelasticity measuring device (10A) can measure the viscoelasticity of the cheeks or forehead while supporting the user's face.

[0061] The skin viscoelasticity measuring device (10A) may include a housing (11A), a support (13A), a guide (15A), a seating groove (17A), a contact part (100A), a moving part (200A), a measuring part (300A), and a control part (400A).

[0062] The housing (11A) can hold and support other components of the skin viscoelasticity measuring device (10A). As shown in FIG. 6, a support (13A), a guide (15A), and a seating groove (17A) may be disposed on the front of the housing (11A). Additionally, a moving part (200A) may be disposed on the upper part of the housing (11A).

[0063] A support member (13A) may be positioned on a guide (15A) located on the front of a housing (11A) to support the user's face. In one embodiment, the support member (13A) may be positioned on the inner lower part of the guide (15A) to support the user's chin and may include a concave groove. The user may contact their forehead with a seating groove (17A) that includes a concave groove formed on the upper part of the guide (15A) while the user's chin is in contact with the groove of the support member (13A). Accordingly, the user's face is supported by the support member (13A) and the seating groove (17A), and in this state, the contact portion (100A) may come into contact with the user's facial skin. In one embodiment, the position and height of the support member (13A) may be appropriately adjusted according to the user's face length or area.

[0064] The guide (15A) is positioned on the front of the housing (11A) and may include an opening on the inside to allow the user's face to be fitted. As shown in FIG. 6, a support (13A) may be positioned on the inner lower part of the guide (15A), and a seating groove (17A) may be formed on the upper part of the guide (15A). The guide (15A) includes a frame surrounding the opening, and the user can hold the frame to maintain the position of the face.

[0065] In one embodiment, the support (13A) and / or the seating groove (17A) can check whether the user's face is seated through a sensor.

[0066] The contact portion (100A) may be positioned to face the user's face, which is seated on the support (13A). As shown in FIGS. 6 and 7, the contact portion (100A) may be positioned such that one end is connected to the moving portion (200A) and the other end faces the user's face. A probe (110A) that makes direct contact with the user's skin may be positioned at the other end of the contact portion (100A). As shown in FIG. 7, the probe (110A) is positioned at the end of the main body of the contact portion (100A) facing the skin and may be hemispherical. When the contact portion (100A) is moved by the moving portion (200A) and comes into contact with the skin, the probe (110A) presses into the skin by a predetermined length L. The probe (110A) may be made of a metal material.

[0067] The moving part (200A) is positioned on one side of the housing (11A) and moves the contact part (100A) by receiving a signal from the control part (400). The moving part (200A) can press the contact part (100A) into the skin to a maximum insertion depth while moving in three different directions. The moving part (200A) may include a stage (210A) positioned on the upper front of the housing (11A) and a moving member (220A) having one end connected to the stage (210A) and the other end connected to the contact part (100A). The stage (210A) may be movable in two different directions, for example, in the height direction and the width direction, and the moving member (220A) may be movable in the length direction while connected to the stage (210A). When the control unit (400A) sends a signal, the stage (210A) moves to move the contact portion (100A) to a skin position where viscoelasticity is to be measured, and the moving member (220A) moves to press the contact portion (100A) into the skin.

[0068] The measuring unit (300A) can measure the force applied when the contact unit (100A) presses into the skin in real time and transmit it to the control unit (400A). As shown in FIG. 7, the measuring unit (300A) includes a load cell placed inside the contact unit (100A) and can measure the force with which the probe (110A) presses into the skin. The measuring unit (300A) can measure the force applied in real time until the probe (110A) presses into the skin to a maximum insertion depth L while in contact with the skin.

[0069] The control unit (400A) is connected to the contact unit (100A), the moving unit (200A), and the measuring unit (300A) via wired or wireless means and controls the contact unit (100A), the moving unit (200A), and the measuring unit (300A). In one embodiment, the control unit (400A) can control the moving unit (200A) to indent to a maximum indentation depth L while the contact unit (100A) is in contact with the skin. Furthermore, the control unit (400A) can fit a skin viscoelasticity model using data regarding the force measured by the measuring unit (300A) during the indentation process, a known probe radius, Poisson's ratio, and the maximum indentation depth of the contact unit (100A), and calculate the elastic modulus and the time constant (viscosity coefficient). The control unit (400A) can verify whether the skin is being indented while the contact unit (100A) is in contact with the skin. In one embodiment, when a force exceeding a certain range is applied to the measuring unit (300A) while the probe (110A) of the contact unit (100A) is in contact with the skin, the control unit (400A) uses the moving unit (200A) to adjust the position of the contact unit (100A) so that it is further away from the skin, so that the force applied to the measuring unit (300A) is maintained within a certain range. Additionally, the control unit (400A) can check whether the contact unit (100A) is separated from the skin without contacting it based on the force measured by the measuring unit (300A). In one embodiment, when no force is applied to the measuring unit (300A) after the moving unit (200A) moves the contact unit (100A) to the contact position, the control unit (400A) uses the moving unit (200A) to adjust the position of the contact unit (100A) so that it is closer to the skin, so that the force applied to the measuring unit (300A) is maintained within a certain range.

[0070] The operation of the skin viscoelasticity measuring device (10A) is described as follows.

[0071] When the user places their chin on the support (13A) and their forehead on the seating groove (17A), the control unit (400A) sends a signal to the moving unit (200A). The control unit (400A) controls the moving unit (200A) based on the position information entered by the user or pre-stored position information, and accordingly, the stage (210A) of the moving unit (200A) moves in the height and width directions, moving the contact unit (100A) to a designated position. Then, the moving member (220A) moves in the length direction, bringing the contact unit (100A) into contact with the skin. When the force measured by the measuring unit (300A) in the contact state satisfies a predetermined range, the control unit (400A) sends an indentation signal to the moving unit (200A). Then, as the moving member (220A) of the moving unit (200A) moves toward the skin, the probe (110A) of the contact unit (110A) indents the skin. While the moving member (220A) moves to the maximum indentation depth L, the measuring unit (300A) measures the applied force in real time and transmits it to the control unit (400A). The control unit (400A) fits the measured force to a mathematical formula for a viscoelastic model based on the maximum indentation depth L, the diameter of the probe (110A), and the Poisson ratio of the skin. Additionally, the control unit (400A) calculates the elastic modulus and the time constant (viscosity coefficient) of the skin viscoelastic model based on the fitting result, and transmits the fitting result and the elastic modulus and time constant (viscosity coefficient) of the skin viscoelastic model to the user through a display or the like.

[0072] Through such a configuration, the skin viscoelasticity measuring device (10A) according to one embodiment can indent the contact portion (100A) to a preset indentation depth and calculate the viscoelasticity characteristics of the skin based on the force measured during the process and the skin viscoelasticity model.

[0073] FIG. 8 shows a skin viscoelasticity measuring device (10B) according to another embodiment, and FIG. 9 and FIG. 10 show the operation of a skin viscoelasticity measuring device (10B) according to another embodiment.

[0074] The skin viscoelasticity measuring device (10B) according to the present embodiment differs in some configurations of the contact part (100B), moving part (200B), measuring part (300B), and control part (400B) compared to the skin viscoelasticity measuring device (10) described above, and may further include a housing (11B) and an opening (12B). For convenience of explanation, the skin viscoelasticity measuring device (10B) will be described below focusing on configurations different from the skin viscoelasticity measuring device (10), and descriptions of identical configurations may not be repeated.

[0075] Referring to FIG. 8, the skin viscoelasticity measuring device (10B) can measure the viscoelasticity of the skin while attached to or placed on the user's skin (S). In one embodiment, the skin viscoelasticity measuring device (10B) can measure the viscoelasticity while placed on the user's cheek or forehead, etc.

[0076] The skin viscoelasticity measuring device (10B) may include a housing (11B), a contact part (100B), a moving part (200B), a measuring part (300B), and a control part (400B).

[0077] The housing (11B) may hold and support other components of the skin viscoelasticity measuring device (10B). As shown in FIGS. 9 and 10, the housing (11B) has a square box shape and may accommodate a contact portion (100B), a moving portion (200B), and a measuring portion (300B) inside. The housing (11B) has an opening (12B) on the side facing the skin, through which the contact portion (100B) can come into contact with the skin. The area of ​​the opening (12B) may be larger than the area of ​​the probe (110B) of the contact portion (110B). The housing (11B) may include a small amount of adhesive, etc., at the end in contact with the skin to maintain a more stable position when placed on the user's skin.

[0078] One end of the contact portion (100B) is connected to the moving portion (200B), and the other end is positioned toward the opening (12B). The contact portion (100B) may include a probe (110B) on the side that contacts the skin and a support portion (120B) positioned between the probe (110B) and the moving portion (200B). As shown in FIG. 9, before measuring the viscoelasticity of the skin, the probe (110B) contacts the skin without pressing it while being pulled up by the support portion (120B). Then, as shown in FIG. 10, when the moving portion (200B) is operated, the support portion (120B) extends while returning to its original state, and the probe (110B) presses it against the skin. In one embodiment, the probe (110B) has a convex shape at the end that contacts the skin, and the support portion (120B) may be a spring.

[0079] The moving part (200B) moves the contact part (100B) by receiving a signal from the control part (400B). In one embodiment, the moving part (200B) may be an electromagnet and may be magnetic by receiving power from a power source that receives a control signal from the control part (400B) or by receiving power directly from the control part (400B). The magnetic moving part (200B) pulls the contact part (100B) upward and compresses it, and in this state, the probe (110B) of the contact part (100B) may be positioned on the same surface as the opening (12B) that contacts the skin. That is, while the moving part (200B) is magnetic, the probe (110B) can maintain a position that contacts the skin but does not press into the skin. Then, when the control unit (400B) transmits a release signal to the moving unit (200B), the power supplied to the moving unit (200B) is cut off, and as the support unit (120B) of the contact unit (100B) extends, the probe (110B) can press against the skin. Although the drawing shows the moving unit (200B) located inside the housing (11B), the moving unit (200B) may be placed outside the housing (11B) as long as it can be connected to the control unit (400B). Here, the contact unit (100B) may be made of metal.

[0080] The measuring unit (300B) measures the displacement of the contact unit (100B) in real time and transmits it to the control unit (400B). As shown in FIG. 9, the measuring unit (300B) is positioned on one side of the inner surface of the housing (11B) adjacent to the moving unit (200B) and can measure the distance to the contact unit (100B). In one embodiment, the measuring unit (300B) can measure the distance to the probe (110B) in real time as a light sensor or a ToF sensor, measure the indentation depth of the probe (110B), and transmit it to the control unit (400B). As shown in FIG. 9, when the moving unit (200B) pulls the contact unit (100B) and the probe (110B) is in contact with the skin, the measuring unit (300B) measures the distance L1 to the rear of the probe (110B). And as shown in FIG. 10, when the moving part (200B) releases the contact part (100B) and the probe (110B) is pressed into the skin, the measuring part (300B) measures the distance L2 to the rear of the probe (110B). Then, the measuring part (300B) can measure the displacement (L2-L1) of the probe (110B) and the position when the probe (110B) is pressed to the maximum insertion depth while in contact with the skin in real time and transmit them to the control part (400B).

[0081] The control unit (400B) is connected to the contact unit (100B), the moving unit (200B), and the measuring unit (300B) via wired or wireless connections and controls the contact unit (100B), the moving unit (200B), and the measuring unit (300B). Before measuring viscoelasticity, the control unit (400B) causes the moving unit (200B) to maintain a state of contact without the contact unit (100B) pressing against the skin, and during viscoelasticity measurement, the moving unit (200B) can cause the contact unit (100B) to press against the skin. In one embodiment, the control unit (400B) supplies power to the moving unit (200B), which is an electromagnet, so that the moving unit (200B) pulls the contact unit (100B) upward, and in this state, the probe (110B) comes into contact with the skin. Then, the control unit (400B) cuts off power to the moving unit (200B) so that the moving unit (200B) releases the contact unit (100B). Additionally, the control unit (400B) can fit a skin viscoelasticity model using data regarding displacement measured by the measuring unit (300B) during the indentation process, the radius of the probe (110B) known in advance, the Poisson ratio, and the restoring force of the contact unit (100B), and calculate the elastic modulus and the time constant (viscosity coefficient). The control unit (400B) can check whether the skin is being indented while the contact unit (100B) is in contact with the skin. In one embodiment, when the probe (110B) of the contact part (100B) is in contact with the skin and a distance exceeding a certain range is detected by the measuring part (300B), the control part (400B) supplies greater power to the moving part (200B) to adjust the position of the contact part (100B) so that it is further away from the skin. Additionally, the control part (400B) can check whether the contact part (100B) is separated from the skin without contacting it based on the force measured by the measuring part (300B). In one embodiment, when the probe (110B) of the contact part (100B) is in contact with the skin and a distance less than a certain range is detected by the measuring part (300B), the control part (400B) reduces the power supplied to the moving part (200B) to adjust the position of the contact part (100B) so that it is closer to the skin.The control unit (400B) may be positioned physically separated from other components of the skin viscoelasticity measuring device (10B) or positioned on one side of the housing (11B).

[0082] The operation of the skin viscoelasticity measuring device (10B) is described as follows.

[0083] First, a skin viscoelasticity measuring device (10B) is positioned at the skin location where viscoelasticity is to be measured. The housing (11B) is placed at the skin location where measurement is to be performed, and the control unit (400B) sends a signal to the moving unit (200B). The moving unit (200B), which receives power, pulls the contact unit (100B) upward with a preset force so that the probe (110B) of the contact unit (100B) contacts the skin but maintains a state without pressing the skin. When the distance measured by the measuring unit (300B) in the contact state satisfies a preset value, the control unit (400B) sends a release signal to the moving unit (200B). Then, as the power supplied to the moving unit (200B) is cut off, the support unit (120B) of the contact unit (100B) extends and presses the skin. The measuring unit (300B) measures the distance to the probe (110B) in real time while the probe (110B) moves from its initial position to the maximum indentation depth and transmits this to the control unit (400B). The control unit (400B) fits the measured force to a viscoelastic model using a mathematical formula based on the displacement of the probe (110B), i.e., the difference in distance between the contact state and the maximum indentation depth, the diameter of the probe (110B), and the Poisson ratio of the skin. Additionally, the control unit (400B) calculates the elastic modulus and the time constant (viscosity coefficient) of the skin viscoelastic model based on the fitting result, and transmits the fitting result and the elastic modulus and time constant (viscosity coefficient) of the skin viscoelastic model to the user through a display or the like.

[0084] Through this configuration, the skin viscoelasticity measuring device (10B) according to one embodiment can measure the viscoelasticity of the skin while the entire contact part (100B), moving part (200B), and measuring part (300B) are placed on the user's skin. Therefore, even if the user moves, the relative position between the skin viscoelasticity measuring device (10B) and the user's skin does not change, so the viscoelasticity characteristics of the skin can be calculated more accurately.

[0085] FIGS. 11 and 12 illustrate the operation of a skin viscoelasticity measuring device (10C) according to another embodiment.

[0086] The skin viscoelasticity measuring device (10C) according to the present embodiment may have different configurations of the contact part (100C) and the moving part (200C) compared to the skin viscoelasticity measuring device (10B) described above. For convenience of explanation, the skin viscoelasticity measuring device (10C) will be described below focusing on configurations different from the skin viscoelasticity measuring device (10B), and descriptions of identical configurations may not be repeated.

[0087] Referring to FIG. 11, the skin viscoelasticity measuring device (10C) can measure the viscoelasticity of the skin while attached to or placed on the user's skin (S). In one embodiment, the skin viscoelasticity measuring device (10C) can measure the viscoelasticity while placed on the user's cheek or forehead, etc.

[0088] The skin viscoelasticity measuring device (10C) may include a housing (11C), a contact part (100C), a moving part (200C), a measuring part (300B), and a control part (400C).

[0089] The housing (11C) may hold and support other components of the skin viscoelasticity measuring device (10C). As shown in FIG. 11, the housing (11C) includes a stepped portion (19C) that supports the contact portion (100C) on its inner surface, and the stepped portion (19C) may be positioned higher than the inner bottom surface of the housing (11C). Thus, a portion of the contact portion (100C) is spaced apart from the bottom surface of the housing (11C) and may not collide with the bottom surface of the housing (11C) during the process of the bent contact portion (100C) returning to its original position. The housing (11C) includes an opening (12B) on the surface facing the skin, through which the contact portion (100C) can press against the skin.

[0090] The contact portion (100C) has the shape of a long rod or plate, with one end positioned on the stepped portion (19C) and the other end protruding toward the opening (12C). The contact portion (100C) may include a probe (110C) positioned toward the opening (12C) and a support portion (120C) extending from the stepped portion (19C). Before viscoelasticity measurement, the support portion (120C) is maintained in a state of being pulled upward by the moving portion (200C), and accordingly has an upwardly bent shape as shown in FIG. 11. Then, when the moving portion (200C) releases the contact portion (100C), the contact portion (100C) returns to its original state, allowing the probe (110C) to press into the skin. In one embodiment, the contact portion (100C) may be made of an elastic material such as a metal rod or a metal plate. Additionally, the contact portion (100C) may further include a connecting portion (130C) that is optionally connected to the moving portion (200C). As shown in FIG. 11, the connecting portion (130C) is a magnet placed on the upper surface of the support portion (120C). When the moving portion (200C) becomes magnetic, the connecting portion (130C) is pulled toward the moving portion (200C), and the support portion (120C) may bend. And as shown in FIG. 12, when the moving portion (200C) loses its magnetism, the connecting portion (130C) is separated from the moving portion (200C), and the support portion (120C) may return to its original position.

[0091] The moving part (200C) moves the contact part (100C) by receiving a signal from the control part (400C). In one embodiment, the moving part (200C) may be an electromagnet and may be magnetic by receiving power from a power source that receives a control signal from the control part (400C) or by receiving power directly from the control part (400C). The magnetic moving part (200C) pulls the contact part (100C), that is, the connecting part (130C) of the contact part (100C), upward to bend the contact part (100C), and in this state, the probe (110C) of the contact part (100C) may be placed on the same surface as the surface that contacts the skin of the opening (12C). That is, while the moving part (200C) is magnetic, the probe (110C) can maintain a position that contacts the skin but does not press into the skin. Then, when the control unit (400C) transmits a release signal to the moving unit (200C), the power supplied to the moving unit (200C) is cut off, and as the contact unit (100C) returns to its original position, the probe (110C) can press against the skin. Although the drawing shows the moving unit (200C) located inside the housing (11C), the moving unit (200C) may be placed outside the housing (11C) as long as it can be connected to the control unit (400C).

[0092] The operation of the skin viscoelasticity measuring device (10C) is described as follows.

[0093] First, a skin viscoelasticity measuring device (10C) is positioned at the skin location where viscoelasticity is to be measured. The housing (11C) is placed at the skin location where measurement is to be performed, and the control unit (400C) sends a signal to the moving unit (200C). The moving unit (200C), which receives power, pulls the support unit (120C) of the contact unit (100C) upward with a preset force and connects to the connecting unit (130C), thereby ensuring that the moving unit (200C) maintains a state where the probe (110C) of the contact unit (100C) contacts the skin without pressing into the skin. When the distance (L1) measured by the measuring unit (300C) in the contact state satisfies a preset value, the control unit (400C) sends a release signal to the moving unit (200C). Then, as the power supplied to the moving part (200C) is cut off, the connection between the connecting part (130C) of the contact part (100C) and the moving part (200C) is severed, and as the support part (120C) returns to its original state, the probe (110C) presses into the skin. The measuring part (300C) measures the distance to the probe (110C) in real time while the probe (110C) moves from the initial position to the maximum insertion depth and transmits it to the control part (400C). The distance measured by the measuring part (300C) at the maximum insertion depth may be L2 in FIG. 12. The control part (400C) fits the measured force to a mathematical formula for a viscoelastic model based on the displacement of the probe (110C), that is, the difference in distance between the contact state and the probe (110C) at the maximum insertion depth, the diameter of the probe (110C), and the Poisson ratio of the skin. Additionally, the control unit (400C) calculates the elastic modulus and time constant (viscosity coefficient) of the skin viscoelastic model based on the fitting result, and transmits the fitting result and the elastic modulus and time constant (viscosity coefficient) of the skin viscoelastic model to the user through a display, etc.

[0094] Through this configuration, the skin viscoelasticity measuring device (10C) according to one embodiment can measure the viscoelasticity of the skin while the entire contact part (100C), moving part (200C), and measuring part (300C) are placed on the user's skin. Therefore, even if the user moves, the relative position between the skin viscoelasticity measuring device (10C) and the user's skin does not change, so the viscoelasticity characteristics of the skin can be calculated more accurately.

[0095] FIGS. 13 and 14 illustrate the operation of a skin viscoelasticity measuring device (10D) according to another embodiment.

[0096] The skin viscoelasticity measuring device (10D) according to the present embodiment includes a protrusion (17D) and may have different configurations of the contact portion (100D) compared to the skin viscoelasticity measuring device (10C) described above. For convenience of explanation, the skin viscoelasticity measuring device (10D) will be described below focusing on configurations different from the skin viscoelasticity measuring device (10D), and descriptions of identical configurations may not be repeated.

[0097] Referring to FIG. 13, the skin viscoelasticity measuring device (10D) can measure the viscoelasticity of the skin while attached to or placed on the user's skin (S). In one embodiment, the skin viscoelasticity measuring device (10D) can measure the viscoelasticity while placed on the user's cheek or forehead, etc.

[0098] The skin viscoelasticity measuring device (10D) may include a housing (11D), a contact part (100D), a moving part (200D), a measuring part (300D), and a control part (400D).

[0099] The housing (11D) may hold and support other components of the skin viscoelasticity measuring device (10D). As shown in FIG. 13, the housing (11D) may include a protrusion (17D) on its inner surface. The protrusion (17D) is positioned near the center of the housing (11D) in the height direction and protrudes towards the center from the inner surface of the housing (11D). The protrusion (17D) is positioned between the contact portion (100D) and the moving portion (200D), and a measuring portion (300D) may be positioned on one side. As shown in FIG. 13, the protrusion (17D) extends to the center of the housing (11D) in the radial or width direction, and a measuring portion (300D) may be positioned on the bottom surface. The measuring portion (300D) can measure the displacement of the contact portion (100D) while positioned on the protrusion (17D).

[0100] The contact portion (100D) is supported by the inner surface of the housing (11D) and may have a cross-sectional shape identical or similar to that of the housing (11D). The edge of the contact portion (100D) may be in contact with the inner surface of the housing (11D), and the center may include a probe (110D) positioned to face an opening (12D), a support portion (120D) supporting the probe (110D), and a connection portion (130D) positioned at the top of the probe (110D). The support portion (120D) may be made of a material that is elastic and deformable by the displacement of the probe (110D), such as a membrane, a film, or a metal thin film. The connection portion (130D) is a magnet, and when voltage is applied to the moving portion (200D), it can be pressed downward to press the skin (S) or pulled upward to be separated from the skin (S).

[0101] Before measuring viscoelasticity, the support member (120D) has a flat shape relative to the ground or skin (S), and the probe (110D) can maintain a state where it contacts the skin (S) but does not press into the skin (S). Then, when voltage is applied to the moving member (200D) and the moving member (200D) presses the connecting member (130D) toward the skin (S), the probe (110D) can be pressed into the skin (S).

[0102] The moving part (200D) moves the contact part (100D) by receiving a signal from the control part (400D). In one embodiment, the moving part (200D) may be an electromagnet and may be magnetic by receiving power from a power source that receives a control signal from the control part (400D) or by receiving power directly from the control part (400D). In the initial state, no voltage is applied to the moving part (200D), and the moving part (200D) does not exhibit magnetism. In this state, the probe (110D) maintains a state where it contacts the skin (S) but does not apply pressure to the skin (S). Next, when voltage is applied to the moving part (200D), the moving part (200D) becomes magnetic, presses the connecting part (130D) downward, and the probe (110D) presses into the skin (S). And the measuring unit (300D) measures the displacement of the probe (110D) in real time while the probe (110D) presses into the skin (S) and transmits it to the control unit (400D). That is, unlike the previously described embodiment, the skin viscoelasticity measuring device (10D) can press into the skin (S) using the repulsive force between the contact unit (100D) and the moving unit (200D).

[0103] In one embodiment, the control unit (400D) can press the skin (S) by controlling the force applied to the contact unit (100D) or press the skin (S) by controlling the displacement of the contact unit (100D). The control unit (400D) calculates in advance the magnitude of the force exerted by the movable unit (200D) on the connection unit (130D) based on the distance between the movable unit (200D) and the connection unit (130D) and the voltage applied to the movable unit (200D). Then, based on the magnitude of the calculated force, a preset voltage is applied to the movable unit (200D) to press the contact unit (100D) with a desired force, thereby pressing the skin (S). Additionally, the measuring unit (300D) can measure the displacement of the probe (110D) in real time during the process of the probe (110D) pressing the skin (S) and transmit it to the control unit (400D). That is, the control unit (400D) can apply a preset force to the contact unit (100D) and measure the displacement accordingly.

[0104] Alternatively, the control unit (400D) can control the voltage applied to the moving unit (200D) based on the real-time displacement of the probe (110D) measured by the measuring unit (300D). The control unit (400D) can apply an arbitrary voltage to the moving unit (200D) and, accordingly, apply a desired displacement to the probe (110D) by controlling the voltage applied to the moving unit (200D) using a known control method, such as PID control, based on the real-time displacement of the probe (110D) measured by the measuring unit (300D).

[0105] In this way, the control unit (400D) can control the probe (110D) by applying a preset force to the probe (110D) or by applying a preset displacement.

[0106] The operation of the skin viscoelasticity measuring device (10D) is described as follows.

[0107] First, a skin viscoelasticity measuring device (10D) is positioned at the skin location where viscoelasticity is to be measured. The housing (11D) is placed at the skin location where measurement is to be performed, and in this state, the end of the probe (110D) remains in contact with the skin. When the distance (L1) measured by the measuring unit (300D) in the contact state satisfies a preset value, the control unit (400D) sends a pressure signal to the moving unit (200D). Then, the control unit (400D) applies voltage to the moving unit (200D). Here, the control unit (400D) applies a known voltage to the moving unit (200D) to apply pressure to the probe (110D) with a preset force, and the measuring unit (300D) can measure the displacement of the probe (110D) in real time and transmit it to the control unit (400D). Alternatively, the control unit (400D) can control the voltage applied to the moving unit (200D) so that the probe (110D) presses the skin (S) by a preset displacement based on the displacement of the probe (110D) measured in real time by the measuring unit (300D) after applying any voltage to the moving unit (200D).

[0108] The measuring unit (300D) measures the distance to the probe (110D) in real time while the probe (110D) moves from the initial position to the maximum indentation depth and transmits it to the control unit (400D). The distance measured by the measuring unit (300D) at the maximum indentation depth may be L2 in FIG. 14. The control unit (400D) fits the measured force to a mathematical formula for a viscoelastic model based on the displacement of the probe (110D), i.e., the difference in distance between the contact state and the probe (110D) at the maximum indentation depth, the diameter of the probe (110D), and the Poisson ratio of the skin. Additionally, the control unit (400D) calculates the elastic modulus and the time constant (viscous coefficient) of the skin viscoelastic model based on the fitting result, and transmits the fitting result and the elastic modulus and the time constant (viscous coefficient) of the skin viscoelastic model to the user through a display, etc.

[0109] Through this configuration, the skin viscoelasticity measuring device (10D) according to one embodiment can measure the viscoelasticity of the skin while the entire contact part (100D), moving part (200D), and measuring part (300D) are placed on the user's skin. Therefore, even if the user moves, the relative position between the skin viscoelasticity measuring device (10D) and the user's skin does not change, so the viscoelasticity characteristics of the skin can be calculated more accurately. In addition, by using the support part (120D), the probe (110D) can be positioned more accurately at the center of the skin viscoelasticity measuring device (10D) or the housing (11D), and the radial size of the skin viscoelasticity measuring device (10D) can be reduced. Furthermore, the skin viscoelasticity measuring device (10D) can press the probe (110D) toward the skin in a more intuitive way by applying voltage to the moving part (200D) by the control part (400D). In particular, the skin viscoelasticity measuring device (10D) can control the probe (110D) using both a force application method and a displacement application method through such a control method. Therefore, the skin viscoelasticity measuring device (10D) can measure the viscoelasticity of the skin while pressing the skin with various forces and displacements.

[0110] FIG. 15 shows the measurement results of a skin viscoelasticity measuring device (10 to 10D) according to one embodiment.

[0111] A skin viscoelasticity measuring device (10 to 10D) according to one embodiment receives user personal information (name, gender, age, etc.) or retrieves it from an external server and then performs skin viscoelasticity measurement. During the measurement process, a skin viscoelasticity model can be fitted using the applied force and the displacement measured accordingly, or the applied displacement and the force measured accordingly, and known information (maximum indentation depth or maximum restoring force, Poisson's ratio of the skin, and diameter of the probe). As shown in FIG. 15, the fitted result can be visually displayed through a graph. Additionally, based on the fitting result, the elastic modulus and the time constant (viscosity coefficient) of the skin viscoelasticity model can be calculated and similarly displayed visually. Furthermore, the skin viscoelasticity measuring device can score the condition of the skin based on the calculated elastic modulus and the time constant (viscosity coefficient). In one embodiment, the skin viscoelasticity measuring device (10 to 10D) can score the amount of collagen and elastin that can be inferred from the elastic modulus corresponding to each time constant, and assign an average value of 100 points. In one embodiment, the measurement result as shown in FIG. 15 can be verified on a user terminal or server by implementing the control unit of the skin viscoelasticity measuring device in the form of a program or application.

[0112] A method for measuring skin viscoelasticity according to one embodiment may include the steps of: contacting a probe with the skin; moving the probe by a preset displacement or by a preset force to press the skin; measuring the force or displacement resulting from the probe pressing the skin; and calculating the viscoelasticity characteristics of the skin by fitting the measured force or displacement to a skin viscoelastic model in which a system consisting of one elastic body and two systems consisting of one elastic body and one buffer body are connected in parallel.

[0114] Examples

[0115] The viscoelasticity of human skin was measured using a skin viscoelasticity measuring device and a skin viscoelasticity measuring method according to one embodiment. The viscoelasticity of the skin (cheek) was measured for a total of three experimental subjects (Experimental Example 1: Male 1 (24 years old), Experimental Example 2: Male 2 (27 years old), Experimental Example 3: Female 1 (27 years old)). The viscoelasticity measuring method utilized a method of applying displacement to the skin viscoelasticity measuring device and measuring the resulting force. That is, with the probe in contact with the skin, the probe was pressed into the skin to the maximum indentation depth, and the force applied to the probe during this process was measured. Then, the experimental results were fitted by substituting the force measured in real time, the known radius of the probe, and the Poisson ratio into a mathematical formula. In Fig. 16, the thick solid line represents Experimental Example 1 of Fig. 17, the dotted line represents Experimental Example 2 of Fig. 17, and the thin solid line represents Experimental Example 3 of Fig. 17. The elastic modulus and time constant of each experimental example obtained therefrom are shown in FIG. 17. As shown in FIG. 17, E1 and E of Experimental Example 3 ∞ It can be seen that E2 of Experimental Example 2 is the largest. Also, it can be seen that τ1 and τ2 of Experimental Example 2 are the largest. Additionally, since both E1 and E2 of Experimental Example 1 were smaller than those of other experimental examples, and τ1 and τ2 were also smaller than those of other experimental examples, it can be inferred that the amount of fibrous proteins (collagen and elastin) is small.

[0116] As such, the skin viscoelasticity measuring device and skin viscoelasticity measuring method according to one embodiment can quantify and calculate the elasticity of the skin as an elastic modulus and the viscosity as a thial constant (or viscosity coefficient), and by comparing the magnitudes of the elastic modulus and the thial constant, the state of the fibrous proteins and substrates constituting the skin can be easily identified.

[0117] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative. Those skilled in the art will fully understand that various modifications and equivalent alternative embodiments are possible from the embodiments. Accordingly, the true technical scope of protection of the present invention should be determined based on the appended claims.

[0118] The term "the above" or similar designations in the description of the invention and claims may refer to both singular and plural forms unless specifically limited otherwise. Furthermore, where a range is described in the embodiments, it is considered to include the invention with respect to individual values ​​within said range (unless otherwise stated), and is equivalent to describing each individual value constituting said range in the description of the invention. Additionally, regarding the steps constituting the method according to the embodiments, the steps may be performed in a suitable order unless explicitly stated or otherwise stated. The embodiments are not necessarily limited by the order in which the steps are described. The use of all examples or exemplary terms (e.g., etc.) in the embodiments is merely for the purpose of describing the embodiments in detail, and the scope of the embodiments is not limited by said examples or exemplary terms unless otherwise limited by the claims. Furthermore, a person skilled in the art will understand that various modifications, combinations, and changes may be made according to design conditions and factors within the scope of the claims or equivalents to which they are added. Explanation of the symbols

[0119] 10: Skin Viscoelasticity Measuring Device 100: Contact part 200: Moving part 300: Measurement section 400: Control unit

Claims

Claim 1 A contact part including a probe at its tip that contacts the user's skin and presses into the skin; a measuring part that measures the force applied and the resulting displacement during the process of the contact part pressing into the skin, or the displacement and the resulting force applied during the process of the contact part pressing into the skin; a control part that simulates the viscoelasticity of the skin as a skin viscoelasticity model in which a system including at least one elastic body and two systems each including at least one elastic body and one buffer body are connected in parallel, and calculates the viscoelasticity characteristics of the skin by fitting the time history of the measured force or displacement to the skin viscoelasticity model; and a moving part that receives a control signal from the control part and presses the skin by a preset force or moves the probe toward the skin by a preset displacement to press the skin or separate it from the skin; wherein the control part fits the measured force or displacement over time using the following formula E ∞ Skin viscoelasticity measuring device that calculates , E1, E2, τ1 and τ2. Here, F is the measured force, R is the radius of the part where the contact indents the skin, ν is the Poisson's ratio of the skin, d is the depth of indentation of the contact into the skin, E ∞ τ1 represents the elastic modulus of a system containing one elastic body, E1 and E2 represent the respective elastic modulus of two systems containing one elastic and one buffer, and τ1 and τ2 represent the respective time constants of two systems containing one elastic and one buffer. Claim 2 delete Claim 3 A skin viscoelasticity measuring device according to claim 1, wherein the measuring unit includes a load cell that measures the force with which the contact part presses against the skin, and the control unit causes the contact part to press against the skin by a preset displacement while in contact with the skin but without pressing against the skin, and calculates the viscoelasticity characteristics of the skin viscoelasticity model based on the force detected by the load cell according to the displacement of the contact part. Claim 4 delete Claim 5 The skin viscoelasticity measuring device according to claim 1 further comprises: a housing; and a support disposed on one side of the housing and supporting the user's face; wherein the probe is disposed to face the user's face seated on the support, the moving part moves the contact part in three different directions to indent the skin to a preset maximum indentation depth, and the measuring part is disposed on the contact part to measure the force applied as the contact part indents the skin. Claim 6 In claim 1, the skin viscoelasticity measuring device further comprises a housing, wherein the contact portion contacts the skin through an opening formed in the housing, and includes a probe made of a metal material and a support portion made of an elastic material connected to the probe, and the moving portion is an electromagnet controlled by power applied by the control portion, wherein when power is supplied, the support portion is deformed in advance by a preset force, and when power supplied from the control portion is cut off, the support portion is released so that the elastic body presses into the skin, and the measuring portion measures the displacement between the initial state of the contact portion and the state in which it is pressed into the skin. Claim 7 A skin viscoelasticity measuring device according to claim 6, wherein the support member is a spring with one end connected to the housing and the other end connected to the probe, and the control member supplies power to the moving member in an initial state to pull the probe upward, and then cuts off the power supplied to the moving member so that the support member returns to its original position and presses into the skin. Claim 8 A skin viscoelasticity measuring device according to claim 6, wherein the support member is a metal member having one end connected to the housing and the other end connected to the probe, and the control member supplies power to the moving member in an initial state to bend the support member upward, and then cuts off the power supplied to the moving member so that the support member returns to its original position and presses into the skin. Claim 9 A skin viscoelasticity measuring device according to claim 6, wherein the support member is made of a deformable material whose edge is supported on the inner surface of the housing, and the probe is positioned in the center, and the control member applies voltage to the moving member to press the probe toward the skin. Claim 10 In paragraph 6, the above-mentioned housing is a skin viscoelasticity measuring device placed on the skin. Claim 11 The method comprises the steps of: contacting a probe provided at the tip of a contact portion with the skin; moving the probe toward the skin by a preset displacement using a moving portion to apply pressure to the skin, or applying pressure to the skin by a preset force to indent it; measuring the force or displacement resulting from the probe indenting the skin; and fitting the time history of the measured force or displacement to a skin viscoelastic model in which a system comprising at least one elastic body and two systems comprising at least one elastic body and one buffer body, respectively, are connected in parallel to calculate the viscoelastic properties of the skin; wherein the step of calculating the viscoelastic properties of the skin comprises fitting the measured force or displacement over time to the following equation E ∞ A method for measuring skin viscoelasticity, which yields , E1, E2, τ1 and τ2. Here, F is the measured force, R is the radius of the part where the contact indents the skin, ν is the Poisson's ratio of the skin, d is the depth of indentation of the contact into the skin, E ∞ τ1 represents the elastic modulus of a system containing one elastic body, E1 and E2 represent the respective elastic modulus of two systems containing one elastic and one buffer, and τ1 and τ2 represent the respective time constants of two systems containing one elastic and one buffer.

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