JP6750932B2 - Skin tactile measurement method and cosmetic performance evaluation method - Google Patents

Description

The present invention relates to a tactile measurement or tactile sensation method for skin using a device that generates vibration, and a method for evaluating the performance of a skin external preparation such as cosmetics that uses a device that generates vibration.

The phenomenon that a person recognizes vibration is very important, and vibration sensation threshold test for diagnosis of vibration disorder is performed as a disease test using vibration, and it is also used as an index of aging. There is a study using the vibration threshold of.
Further, in recent years, a technique for measuring a tactile sensation represented by a tactile display utilizing vibration has been remarkably developed. In particular, many techniques have been developed for quantifying the sensation of touching an object with a finger or the like and the irritation to the skin using various devices and displaying the same. For example, OPTACON, a method of applying a vibration wavelength to the skin surface to selectively stimulate mechanoreceptors existing at different depths inside the skin (Non-Patent Document 1), a microvibration actuator using a shape memory alloy wire Display (Non-Patent Document 2), a tactile display device in which a large number of ICPF actuators are arranged (Non-Patent Document 3), a tactile display using surface acoustic waves propagating on a piezoelectric substrate (Non-Patent Document 4), a current A tactile display that selectively stimulates sensory receptors using stimulation (Non-Patent Document 5), a tactile display that generates mechanical vibration by using electrostatic attraction by voltage (Non-Patent Document 6), and the like are known. There is.

In addition, as a method for evaluating the function of the skin preparation, the water content of the stratum corneum is measured using a corneometer (Courage+Khazaka) or the transepidermal water loss using a Tevameter (Courage+Khazaka). Measurement, skin hardness measurement using an indent meter (Courage+Khazaka), skin viscoelasticity measurement using a cutometer (Courage+Khazaka), sebometer (Courage+Khazaka), etc. Measurement of the sebum used, friction measurement of the skin using a Fricciometer (Courage+Khazaka) etc. are performed before and after the application of the skin external preparation, and the skin external preparation is changed depending on how these measured values change. It is widely performed to evaluate the function and performance of.

Proc. IEEE Virtual Reality Annual International Symposium 98, 36/42(1998) IEEE, HSI 2013, Sopot. Poland, June 06-08, 2013 The Virtual Reality Society of Japan, 6-4, 323/328(2001) Proc. IEEE VR2001, 13/20(2001) IEICE Transactions, J84-D-II-1, 120/128(2001) IEEE Trans. Man-Machine Systems, MMS-II-1, 72/79(1970) Opt Express. 2011 March 28; 19(7): 6623-6634

However, the perception (sensitivity) of weak vibration is greatly affected by the physical properties of the skin up to the tactile receptors. There is a problem in that, in a vibration sense threshold test or the like, variations in measurement may become large. In particular, in a device such as a tactile display for recognizing minute vibrations, an intended tactile sensation may be recognized differently by an individual.

Therefore, an object of the present invention is to provide a means for stably measuring the vibration threshold and providing a tactile sensation by a tactile device.

In addition, the evaluation of external preparations for skin such as cosmetics according to the prior art is to measure physical properties, and although it is objective, it is only measuring specific physical properties, and the entire skin of a skin preparation is evaluated. Does not necessarily determine the impact on Therefore, a plurality of measurements are often combined and evaluated, and the measurements are complicated. In addition, when a plurality of measurements are performed before and after, it is difficult to track changes caused by permeation and evaporation of the skin external preparation component.
Further, the conventional technique has a problem that a measurement error is likely to occur when the external preparation for skin remains on the skin or when water is present as droplets.

Therefore, an object of the present invention is to provide a means for objectively and simply evaluating the function of a skin external preparation without being restricted by the condition of the surface of the skin.

Therefore, the present inventor examined the cause of the variation in responsiveness of the skin to vibration, and found that the perception (sensitivity) of weak vibration was greatly affected by the physical properties of the skin up to the tactile receptors. It is considered that the influence of the stratum corneum, which is the outermost layer of the skin, is particularly large. As a previous study, the state of internal deformation of a finger when a vibration of 125 Hz was applied was measured by OCT, and it was reported that the state of deformation near the presence of tactile receptors was significantly different due to swelling of the stratum corneum. (Non-patent document 7). However, this document does not relate to tactile measurement. Examining the relationship between the swelling state of the skin and the sense of vibration threshold, the cause of the variation is that the transmission state of the stimulus such as vibration from the skin surface to the sensory receptors inside the skin changes individually, and further It was found that the transmission state changes depending on the water content and elastic modulus on the surface of the stratum corneum. Based on such knowledge, if the moisturizing component-containing composition is applied to the skin to be measured, the water content and elastic modulus of the stratum corneum become constant, so the measured values do not fluctuate and become stable, and accurate measurement becomes possible. The inventors have found that and completed the present invention. It was also found that the function of the skin external preparation can be objectively and simply evaluated by measuring the perception of vibration using a device that generates vibration before and after applying the skin external preparation to the skin to be measured.

That is, the first aspect of the present invention is a tactile measurement or tactile sensation method for skin using a device that generates vibration, wherein the skin is measured after applying the moisturizing component-containing composition to the measured skin. The present invention provides a tactile measurement or a tactile sensation presentation method for.

The second aspect of the present invention is a method for evaluating the function of a skin external preparation using a device that generates vibration, characterized by measuring the perception of vibration before and after the application of the skin external preparation to the skin. The evaluation method is as follows.

Use of the tactile measurement or tactile sensation display method for skin of the present invention enables stable measurement or presentation without being affected by environmental factors or skin conditions.
According to the method for evaluating a skin external preparation of the present invention, the function of the skin external preparation can be evaluated objectively and easily.

The SUS board used for the friction coefficient measurement is shown.

[First invention]
The tactile measurement or tactile presentation method for skin using the device for generating vibration according to the first aspect of the present invention is characterized in that the moisturizing component-containing composition is applied to the skin to be measured in advance and then the measurement or presentation is performed.

The skin to be measured or presented is not particularly limited, and includes fingers, the entire palm, the back of the hand, arms, face, feet, back, abdomen, etc., but the fingers or the entire palm, soles, arms, face are more preferable. preferable.

In the present invention, tactile sensation and tactile sensation include tactile pressure sensation, temperature sensation, pain sensation, and a total sensation thereof, but tactile sensation based on stimulation of sensory receptors is force sensation and skin sensation. In the present invention, the tactile display or the tactile device means both the force display and the skin sense display, but mainly means the skin sense display. In such a skin sensation display, the most important sensations are a feeling of touch, for example, a surface texture feeling such as slippery, rough and slimy, and a material feeling.

The moisturizing component-containing composition used in the present invention may be in the form of containing a moisturizing component and capable of being applied to the skin, that is, in the form of a skin external preparation. The moisturizing component may be a component usually used as a moisturizing component in skin cosmetics, and examples thereof include water, a moisturizing agent, an oil agent (an occluding agent and a softening agent), and a skin barrier functioning agent.

As moisturizers, natural moisturizing factors (NMF) such as amino acids, pyrrolidonecarboxylic acid, lactate; glycerin, propylene glycol, dipropylene glycol, 1,3-butylene glycol, polyethylene glycol, polypropylene glycol, sphingosine, pseudosphingosine, sorbitol And other polyhydric alcohols; and sugars such as hyaluronic acid, maltitol, and mannitol. Examples of the oil agent include ester oil, vegetable oil, animal oil, higher fatty acid, higher alcohol, hydrocarbon oil, silicone oil, fluorine oil and the like. Examples of the skin barrier function agent include sphingosine, pseudo-sphingosine, ceramides, and the like. Among these, lysine, arginine, histidine, kerato NMF represented by the following chemical formula (A) or (B), glycerin, propylene glycol, One or more selected from dipropylene glycol, 1,3-butylene glycol, polyethylene glycol, polypropylene glycol, sphingosine, pseudo-sphingosine, sorbitol, hyaluronic acid, mannitol, tuberose polysaccharide and ceramides are preferable.

Examples of the form of the moisturizing component-containing composition include lotion (aqueous solution), emulsion, gel, cream and the like.

These moisturizing component-containing compositions are preferably applied in an amount that does not impair the normal sensation on the skin.

Means for performing tactile measurement or tactile sensation on the skin to which the composition containing a moisturizing component is applied is not particularly limited. Typical examples of the vibration sense threshold measurement are the AU-02 vibrometer (Rion) and the HVLab vibrometer (Sound and Vibration Research Institute, University of Southampton), but the same principle is not limiting. As a tactile display, A tactile display that uses vibration, such as a vibration spin type such as OPTACON, a micro magnet attached to the skin that is driven by an electromagnet, an air pressure stimulator, and a micro vibration actuator that uses a shape memory alloy wire. Examples thereof include one using an ICPF actuator, one using a surface acoustic wave to give vibration, and one giving a mechanical vibration using an electrostatic attraction force by a voltage.

When tactile measurement and tactile sensation are performed on the skin to which the composition containing a moisturizing component is applied as in the present invention, the measurement data and the tactile sensation presented are stable without being affected by environmental factors and the state of the skin.
[Second invention]
A second aspect of the present invention is a method for evaluating the function of a skin external preparation using a device that generates vibration, characterized by measuring the perception of vibration before and after the application of the skin external preparation to the skin. ..

More specifically, it is a method of determining whether or not a subject feels vibration using a device that generates vibration, and evaluating the function of the external preparation for skin using the result of the judgment, in which vibration is applied to the skin. By using a device to examine the perception of vibration before and after applying a skin external preparation (vibration threshold measurement, tactile display).

The means for applying vibration to the skin used in the present invention is not particularly limited. Typical examples of the vibration sense threshold measurement are the AU-02 vibrometer (Rion) and the HVLab vibrometer (Sound and Vibration Research Institute, University of Southampton), but the same principle is not limiting. As a tactile display, A tactile display that uses vibration, such as a vibration spin type such as OPTACON, a micro magnet attached to the skin that is driven by an electromagnet, an air pressure stimulator, and a micro vibration actuator that uses shape memory alloy wire. Examples thereof include one using an ICPF actuator, one using a surface acoustic wave to give vibration, and one giving a mechanical vibration using an electrostatic attraction force by a voltage.
The frequency of vibration may be such that it is sensed by the sensory receptors of the skin, preferably 10 Hz or more and 500 Hz or less, and more preferably 50 Hz or more and 200 Hz or less.

The external preparation for skin used in the second invention is not particularly limited, but since the function of cosmetics which do not generally act on the inside of the skin such as makeup cosmetics can be easily evaluated by appearance, basic cosmetics, especially moisturizing ingredients. It is preferable to use a containing composition. Examples of such a moisturizing component-containing composition include the composition used in the first invention.

The part to be measured is not particularly limited, and includes fingers, the entire palm, the back of the hand, arms, face, legs, back, abdomen, etc., but the agent to be measured is a liquid, gel, cream, solid (such as wax). In this case, the fingers or the entire palm, the soles, arms, and face are more preferable.

More specifically, the method for investigating the recognition of vibration is as follows. That is, the vibration frequency and the intensity are slowly changed while the means for applying vibration such as the vibration element or the vibration transmission element is kept in contact with the skin surface of the measurement site. The measurer (subject) records whether or not he or she feels vibration by pressing a button connected to the recording device. A record of whether or not this vibration is felt is recorded along with the applied frequency and intensity.
The range of frequencies and the range of strength to be changed can be changed according to the purpose of measurement and the type of external preparation for skin. Only the frequency or only the intensity may be changed, and the intensity and frequency may be constant.

Such measurement is performed, for example, before and after the application of the external preparation for skin, and the two measurement results are compared with each other, whereby the penetration of the external preparation for skin and the effect of the external preparation on skin on the entire skin can be comprehensively evaluated. Also, when it is desired to know the time change after the application of the external preparation for skin, the measurement can be performed at minute time intervals of, for example, every 1 minute and every 2 minutes.

Next, the present invention will be described in more detail with reference to examples.

Example 1
Various blasting processes were applied to the SUS plate, and friction measurement was performed using the SUS plate. Friction was measured by moving a finger on a stainless steel plate whose surface roughness was quantitatively controlled. This operation can be considered as giving a weak vibration of a constant cycle to the finger. It is considered that since PC is the number of peaks, the frequency can be taken, and Ra or Rz can be taken as strength because the height of the peaks. Although this measurement is a measurement of frictional force, it is greatly affected by the flexibility of the stratum corneum. That is, the coefficient of friction is high in the stratum corneum having high flexibility regardless of Ra, and conversely, the coefficient of friction is low in the stratum corneum having low flexibility. At this time, if the physical properties of the stratum corneum are uniform, it is considered that the friction coefficient is close to a value.

Sample preparation with roughness changed stepwise by blasting Sample plate SUS304 60×90×1t
Measuring instrument Tokyo Seimitsu SURFCOM FLEX-50A
Evaluation length 4.0 mm
Measuring speed 0.6mm/s
Cutoff value 0.8 mm

Set the SUS plate on the tactile sensor (HEIDON Type:33) and rub it with the index finger of the right hand with a load of about 0.5N (one-way facing forward, distance 5 cm, speed 3 cm/sec), the tangential force (X axis) The friction coefficient was measured and calculated. As shown in FIG. 1, an unprocessed plate (control) was arranged in the center and a blast plate (treatment) was arranged in the periphery, and the unprocessed two times, and then once each (control to treatment), were sequentially repeated. This trial was conducted on 10 healthy adults (5 men and 5 women, age 28-52) with or without moisturizing lotion 1 (Table 2).
An appropriate amount of lotion was applied to the finger to be measured 10 minutes before the measurement.

The results are shown below. In this trial, the unprocessed plate is rubbed 8 times in total. The friction coefficient at that time is shown in Table 3. It can be seen that the moisturization reduces the standard deviation and the variation in measured values. The results for each roughness are shown in Table 4 (without moisturizer) and Table 5 (with moisturizer). With respect to each roughness, it was clear that the standard deviation decreased when the moisturizer was applied. Table 4 and Table 5, especially comparing standard deviations, are as shown in Table 6. It can be said that due to the moisturizing effect of the lotion, individual differences in the physical properties of the stratum corneum are reduced and the influence of vibration is made uniform. ..

Based on the above results, it can be expected that even in the vibration sensation threshold test, by applying the lotion 1 (Table 2), the measurement is stable in each subject and the variation between subjects is reduced. The specific confirmation method is as follows.
The second finger is measured at 125 Hz using a AU-02 vibrometer in a healthy adult who has no abnormalities in the vibration threshold test. The inspector asks for the presence or absence of sensing in the ascending manner of raising the threshold value in stages, and repeats the operation several times to determine the threshold value. The measurement is performed after acclimatization for 30 minutes in a constant temperature and humidity room at 20° C. and 40%. Performed for 5 consecutive days at a fixed time set by the individual. In order to confirm the effect of moisturizing with lotion, subjects are randomly divided into 2 minutes and cross-over conducted.
In addition, a blank period of 1 week is allowed between the presence/absence tests, and an appropriate amount of lotion is applied to a finger to be measured 10 minutes before the measurement.
The expected results of carrying out the above test are as follows. In other words, the standard deviation in multiple trials for each test subject was reduced by applying a moisturizing agent to any of the test subjects, and the standard deviation in measurement of the vibration threshold was reduced, and the sensory receptors functioned stably. Is expected.
Further, it can be expected that the standard deviation in the measurement of all the subjects (the bottom column of the table) is also reduced by applying the moisturizer, and that the application of the moisturizer reduces the subject dependency of the tactile evaluation.

Example 2
When the function of the external preparation for skin is evaluated using a device that generates vibration, the difference between external preparations and the effect over time can be easily measured. An experiment was conducted to confirm that such measurement is useful.
Various blasting processes were applied to the SUS plate, and friction measurement was performed using the SUS plate. Friction was measured by moving a finger on a stainless steel plate whose surface roughness was quantitatively controlled. This operation can be considered as giving a weak vibration of a constant cycle to the finger. Since PC is the number of peaks, it can be considered as frequency, and Ra or Rz can be considered as strength because it is the height of the peak. Although this measurement is a measurement of frictional force, it is greatly affected by the flexibility of the stratum corneum. That is, the coefficient of friction is high in the stratum corneum having high flexibility regardless of Ra, and conversely, the coefficient of friction is low in the stratum corneum having low flexibility. Therefore, it is considered that the change in the flexibility of the stratum corneum due to the external preparation can be captured.

Sample preparation with roughness changed stepwise by blasting Sample plate SUS304 60×90×1t
Measuring instrument Tokyo Seimitsu SURFCOM FLEX-50A
Evaluation length 4.0 mm
Measuring speed 0.6mm/s
Cutoff value 0.8 mm

Set the SUS plate on a tactile sensor (HEIDON Type: 33), and rub the tangential force (X-axis) with the index finger of the right hand under a load of about 0.5 N (one-way facing forward, distance 5 cm, speed 3 cm/sec). The friction coefficient was measured and calculated. As shown in FIG. 1, an unprocessed plate (control) was arranged in the center and a blast plate (treatment) was arranged in the periphery, and the unprocessed two times, and then once each (control to treatment) were sequentially repeated. In this trial, changes in water, refreshing type lotion and moisturizing type lotion were measured over time in three healthy adults. The toner was applied to the finger in an appropriate amount, and immediately after that, 5 minutes later, and 30 minutes later, the measurement was performed.

The results (average friction coefficient) are shown in Table 8 (untreated, water treated), Table 9 (fresh), and Table 10 (moisturized). In this measurement, regardless of Ra, it can be considered that the stratum corneum is flexible when the coefficient of friction is large, and is even softer when the coefficient of friction is large particularly when Ra is large. Therefore, the total friction coefficient of each Ra was used as an index of the flexibility of the stratum corneum. Although the value of water slightly increased immediately after, it became equivalent to that of untreated water after 30 minutes. The refreshing type became large immediately after, but it reached a value close to untreated in about 5 minutes. The moist type became large immediately after that, and showed a large value until 30 minutes thereafter. From this, it can be considered that the characteristics of each processing are accurately reflected.

As can be seen from the above experiments, the performance of cosmetics can be evaluated to a certain extent by using the friction coefficient with PC or Ra as a parameter.
By the way, for example, in the case of 5 minutes after the water in Table 8, Ra is greatly increased from 0.64 to 0.74, but the friction coefficient is not changed. Also, comparing the refreshing Ra of 0.64 and 0.85 in Table 9, the friction coefficient after 30 minutes is almost the same.
After repeatedly studying these data, the present inventor has found that not only Ra, that is, vibration intensity, but also PC, that is, vibration frequency is affected. As an example, Table 11 shows the rearrangement of water in Table 8 and Table 12 shows the rearrangement of moistness in Table 9 with the product of PC and Ra as a parameter. From this table, it can be understood that, for example, the coefficient of friction after 30 minutes of moistness reflects the product of both, and it is also understood that both PC and Ra affect the coefficient of friction in a complicated manner. it can.

If so, conversely, if the coefficient of friction is used to measure the performance of the cosmetic, it is important to change not only the vibration intensity (Ra) but also the vibration frequency (PC).
From this, it is possible to perform a more detailed cosmetic performance analysis by applying vibrations created by electric signals to the skin, whose frequency and intensity can be easily controlled, and measuring them using the human touch. You can

Claims (3)

A tactile measurement or tactile sensation method for skin using a device that generates vibration, wherein a plurality of devices that generate different vibration frequencies and/or vibration intensities after applying a composition containing a moisturizing component to the skin to be measured are provided. A tactile measurement or tactile presentation method for skin, which comprises contacting the skin to be measured and measuring a vibration sensation or providing a tactile sensation by a tactile device. The composition containing a moisturizing component is lysine, arginine, histidine, kerato NMF represented by the following chemical formula (A) or (B), glycerin, propylene glycol, dipropylene glycol, 1,3-butylene glycol, polyethylene glycol, polypropylene. The tactile measurement or tactile presentation method for skin according to claim 1, which is a composition containing one or more selected from glycol, sphingosine, pseudo-sphingosine, sorbitol, hyaluronic acid, mannitol, tuberose polysaccharide and ceramides.
The tactile measurement or tactile sensation presentation method for skin according to claim 1 or 2, wherein the tactile sensation or tactile sensation to the skin to be measured is a tactile sensation of the skin.