JP7455753B2 - Skin evaluation method and skin evaluation device - Google Patents

Description

The present invention relates to a skin evaluation method and a skin evaluation device.

The tactile sensations of the skin, that is, the sensations that occur when the skin is touched, include tactile sensations related to dryness or moisture of the skin (for example, whether the skin is moist), and tactile sensations related to the roughness of the skin surface (for example, whether the skin is moist or not). whether it is smooth or rough), etc.

Conventionally, such skin feel has often been evaluated by sensory evaluation. However, in recent years, tactile evaluation methods other than sensory evaluation have been proposed. For example, Patent Document 1 discloses that the skin's dry state can be determined by measuring the friction coefficients of the skin on a plurality of flat plates with different surface roughness and using the relationship between the measured friction coefficients as an index. It is disclosed that it will be evaluated. In Cited Document 1, the correlation between the skin condition and the correlation between the surface roughness and the change in the coefficient of friction is determined in advance, and the skin condition of the evaluation target can be evaluated based on the correlation.

JP 2017-225583 Publication

However, in the method disclosed in Patent Document 1, it is necessary to conduct multiple tests using different flat plates in order to obtain data from the skin to be evaluated, which is time-consuming. Furthermore, although the skin condition evaluation in Patent Document 1 uses the relationship between a plurality of friction coefficients as an index, a person's actual sensation may not be reflected in physical characteristics such as the friction coefficient. In other words, the sensory evaluation score does not necessarily change by the amount that the physical characteristics change. Therefore, with conventional methods, there have been cases where it has not been possible to accurately evaluate the skin condition.

In view of the above points, one embodiment of the present invention provides a method that can more easily and accurately evaluate skin texture.

One aspect of the present invention is to detect vibrations generated by relative movement between the skin and a contact body while making contact with the skin, frequency analyze the vibrations to obtain a frequency spectrum, and obtain a frequency spectrum in a predetermined frequency band of the frequency spectrum. This method evaluates the tactile sensation of the skin in light of a predetermined relationship between the spectral intensity in the predetermined frequency band and the sensory evaluation of the tactile sensation based on the spectral intensity.

According to one aspect of the present invention, skin texture can be evaluated more easily and accurately.

FIG. 2 is a flow diagram of a skin evaluation method according to one embodiment of the present invention. 1 is a schematic diagram of a skin evaluation device according to one embodiment of the present invention. This is an example of signal data obtained from vibration. 3A is an example of a frequency spectrum obtained from FIG. 3A. It is a figure which shows the correlation coefficient of the sensory evaluation value of a single evaluation item (smooth) and the power spectrum density for each frequency. It is a figure which shows the correlation coefficient of the sensory evaluation value of a single evaluation item (smooth) and the power spectrum density for each frequency. FIG. 3 is a diagram showing the correlation coefficient between the sensory evaluation value of a single evaluation item (unevenness) and the power spectrum density for each frequency. FIG. 7 is a diagram showing the correlation coefficient between the sensory evaluation value of a single evaluation item (roughness) and the power spectrum density for each frequency. It is a figure which shows the result of principal component analysis of the data obtained regarding several evaluation items. 6 is a diagram showing the principal component loading amount of each evaluation item for the first principal component in the principal component analysis shown in FIG. 5. FIG. 6 is a diagram showing the principal component loading amount of each evaluation item for the second principal component in the principal component analysis shown in FIG. 5. FIG. FIG. 7 is a diagram showing the correlation between the principal component score and the power spectral density for the roughness tactile sensation as a comprehensive tactile sensation for each frequency. FIG. 7 is a diagram showing the correlation between the principal component score and the power spectral density for each frequency regarding the dry/wet tactile sensation as a comprehensive tactile sensation.

In various technical fields including the beauty field, there is a need to easily and accurately evaluate the tactile sensation of the skin, that is, the sensation that occurs when the skin is touched (also referred to as tactile sensation or tactile sensation). The present inventors have discovered that the tactile sensation of the skin is correlated with the spectral intensity in a predetermined frequency band of the frequency spectrum of vibrations caused by relative movement between the skin and a contacting body while in contact with each other. Based on this method, it has been found that the texture of the skin, particularly the rough texture and/or the dry/wet texture of the skin, can be evaluated satisfactorily.

One form of the present invention, which has been made in view of the above findings, is a skin evaluation method, as shown in FIG. (S1) Frequency analysis of the vibration is performed to obtain a frequency spectrum (S2), and based on the spectrum intensity in a predetermined frequency band of the frequency spectrum, the spectral intensity in the predetermined frequency band and the tactile sensation are determined in advance. This is a method (S3) of evaluating the skin feel (skin feel) in light of the relationship with the evaluation.

Further, one form of the present invention is an evaluation device 10 as shown in FIG. Based on the analysis means 30 that analyzes and obtains a frequency spectrum, and the spectral intensity in a predetermined frequency band of the frequency spectrum, in light of the relationship between the spectral intensity in the predetermined frequency band and the sensory evaluation of the tactile sensation, which has been determined in advance. This device is equipped with evaluation means 40 for evaluating the tactile sensation of the skin.

In this specification, "tactile sensation" refers to when the pads of the fingers, palms, etc. are brought into contact with the skin to be evaluated, or when the pads of the fingers, palms, etc. are moved while in contact with the skin, that is, when the skin is stroked or rubbed. It is the feeling that occurs when something happens. This "tactile sensation" may be the tactile sensation of a certain single evaluation item, or may be the overall tactile sensation of a plurality of evaluation items. That is, the tactile sensation evaluated in this embodiment may be a tactile sensation that is generally listed as an evaluation item for skin tactile sensations, or may be a tactile sensation as a higher level concept that includes multiple such tactile sensations. good.

If the overall tactile sensation of two or more evaluation items is evaluated instead of the tactile sensation of a single evaluation item, the skin condition (characteristics) can be comprehensively evaluated, which can be used to determine trends in skin quality, etc. can do.

Among the above-mentioned tactile sensations, this embodiment can particularly favorably evaluate skin roughness tactile sensation and/or dry/wet tactile sensation. "Roughness tactile sensation" is a tactile sensation related to the roughness or fineness of unevenness on the surface of the skin, and is expressed by terms such as bumpy, rough, rough, smooth, smooth, and fine-textured (coarse). One or more tactile evaluation items can be included. In addition, "dry-wet texture" is a texture related to the degree of dryness or moisture of the skin, or the amount of moisture in the skin, and is, for example, an evaluation item expressed by terms such as moist, smooth, dry, and moist. can include one or more tactile sensations.

The "roughness tactile sensation" may be one of the tactile sensations related to skin roughness listed above, or may be a comprehensive tactile sensation of two or more evaluation items. Similarly, the "dry/wet tactile sensation" may be one of the tactile sensations related to skin dryness/wetness exemplified above, or may be a comprehensive tactile sensation of two or more evaluation items. In addition, when the evaluation of "roughness tactile sensation" or "dry/wet tactile sensation" is a comprehensive evaluation including evaluation of the tactile sensation of two or more evaluation items, the number and types of evaluation items included are not particularly limited. For example, the individual evaluation items for tactile sensation mentioned above as an example of "roughness tactile sensation" may be used for comprehensive evaluation of "dry/wet tactile sensation", or vice versa. There may be cases.

The skin to be evaluated according to this embodiment may be skin without any treatment (bare skin), or may be treated with some kind of treatment on the surface, such as cosmetics (especially basic makeup such as lotions and creams). The skin may also be treated after cosmetic treatments such as application of skin care products, washing, shaving or hair removal, massage or stimulation. According to this embodiment, the treatment itself can be evaluated by comparing the evaluation of the skin before and after the treatment.

<Vibration detection (S1)>
In this embodiment, vibrations generated by relative movement of the skin to be evaluated and a contact body while in contact with each other are detected (S1). FIG. 2 shows an example of vibration generation and detection. As shown in FIG. 2, vibration can be generated by, for example, making a reciprocating movement as shown by the double-headed arrow while bringing the cheek part of a person into contact with the pad of a finger.

In the illustrated example, the skin to be evaluated is the person's cheek, but the skin to be evaluated may also be the skin on other parts of the face such as the forehead, chin, nose, etc., or the skin on other parts of the body other than the face. For example, the skin may be the skin of the neck, décolleté (the area from the neck to the chest), back, arms, legs, etc.

In the illustrated example, the contact object is a finger, and the ventral side of the first joint of the finger is brought into contact with the skin surface to be evaluated, but the contact object may also be the palm, arm, face, etc. It may be. Furthermore, the contact body does not need to be a part of the body, and may be an object having a surface imitating the surface shape of human skin, for example, an object covered with artificial skin or the like. Further, the contact body may be a probe made of metal or resin, and may be integrated with vibration detection means 20, which will be described later. However, when actually touching the skin, it is usually done with the pads of the fingers or the palm of the hand. It is possible to generate vibrations in a state close to that of feeling tactile sensation.

Vibration is generated by relative movement between the skin and a contact body while in contact (hereinafter also referred to as relative contact movement), that is, by stroking or rubbing the skin with the contact body (by sliding the contact body on the surface of the skin). (to do so). This relative movement can also be performed while applying some pressure by pressing the contact body against the skin. By applying some pressure, it is possible to generate vibrations in a state similar to the state in which a person actually feels the touch of the skin, which is preferable. Further, in the illustrated example, the relative movement is a reciprocating movement of the contact body within a predetermined length range, but the direction of the movement is not particularly limited. For example, the contact body may be moved so as to repeatedly stroke a predetermined length of the skin surface in one direction, or may be moved so as to draw an arbitrary shape such as a circle or an ellipse.

The generated vibrations are detected by the vibration detection means 20. In this case, the magnitude of the vibration can be measured as a change in one or more of displacement, velocity, and acceleration. Preferably, the magnitude of vibration is measured as a change in acceleration. As the vibration detection means 20, for example, an acceleration sensor such as a 3-axis acceleration sensor, an angular velocity sensor, an angular acceleration sensor, a PVDF film sensor, a strain gauge, a piezo sensor, a laser displacement meter, a photo reflector, a microphone, etc. can be used.

In the illustrated example, the vibration detection means 20 is disposed on the side of the contact body (finger) opposite to the side that contacts the skin (fingernail side), but it detects vibrations that can be used for evaluation. The location where the vibration detection means 20 is placed is not particularly limited as long as it can be detected. The vibration detection means 20 can be placed anywhere on the contact body or on the skin to be evaluated.

Furthermore, the detected vibrations may be directly detected vibrations of the evaluation target (skin) and/or the contact object, or may be generated from the surface of the skin and/or the contact object via the surrounding medium (air). It may be something that has been propagated (sound). However, when directly detecting vibrations of the skin and/or the contact object, it is possible to detect signals near the location where the vibrations occur, and it is also possible to detect signals that occur due to factors other than the relative contact motion between the skin and the contact object. Mixing of vibrations can be reduced. Therefore, as shown in the figure, it is preferable to provide a vibration detection means 20 on the contact body (finger) to detect vibrations from the viewpoint of improving detection accuracy.

<Vibration analysis (S2)>
The vibrations detected by the vibration detection means 20 as described above are converted into electrical signals, sent to the analysis means 30 connected to the vibration detection means 20, and analyzed (FIG. 2). More specifically, the analysis means 30 can generate a frequency spectrum by analyzing the frequency spectrum of the acquired signal.

More specifically, the data detected by the vibration detection means 20 is obtained as an acceleration signal waveform as shown in FIG. 3A. Then, the analysis means 30 performs processing such as Fourier transform and wavelet transform on the above data, thereby obtaining a frequency spectrum as shown in FIG. 3B.

The frequency spectrum represents the magnitude of various frequency components included in the vibration detection signal for each frequency. As shown in FIG. 3B, the frequency spectrum is displayed, for example, as a graph in which the horizontal axis represents frequency (unit: Hz) and the vertical axis represents power spectral density (power value per 1 Hz width, unit: dB/Hz). can do.

Therefore, in the vibration analysis (S2), the spectrum intensity in a predetermined frequency band can be determined from the obtained frequency spectrum. Specifically, the spectral intensity in a predetermined frequency band is the area integral value of the power spectral density in the predetermined frequency band, the area integral value per unit frequency, the center of gravity value, the average value, the median value, and the maximum value. It can be expressed as an index value obtained from one or more of the following.

Note that software such as Matlab (registered trademark) (manufactured by MathWorks) can also be used for at least part of the processing in the vibration analysis and skin evaluation described above.

<Skin evaluation (S3)>
In this embodiment, the skin feel can be evaluated based on the spectrum intensity in a predetermined frequency band of the frequency spectrum acquired as described above. More specifically, the predetermined skin texture can be evaluated in light of the relationship between the spectrum intensity in a predetermined frequency band and the sensory evaluation of the predetermined skin texture, which has been determined in advance. In that case, the spectral intensity in a predetermined frequency band is, as described above, the area integral value of the power spectral density in the predetermined frequency band, the area integral value per unit frequency, the centroid value, the average value, the median value, and the maximum value. It can be expressed as an index value obtained from one or more of the following. Therefore, it is preferable to determine the relationship between such an index value and, for example, a sensory evaluation value in advance, and store the relationship as a database. Alternatively, a model formula may be constructed and saved for the relationship.

(1.Evaluation of tactile sensation as a single evaluation item)
The tactile sensation of a single evaluation item evaluated according to this embodiment includes, for example, evaluation items such as "smooth,""rough,""smooth,""smooth,""crusty,""moist," and "bumpy." The most important thing is the tactile sensation.

To perform the evaluation, as explained in "Vibration detection (S1)" and "Vibration analysis (S2)" above, the vibrations generated by relative movement between the skin and the contact object while in contact are detected. and analyze it to obtain a frequency spectrum. This process is performed on multiple subjects (different skin) and each frequency spectrum is recorded.

On the other hand, regarding one specific item (tactile sensation) to be evaluated, sensory evaluations are performed on multiple objects (skin) by a specialized panel, and the sensory evaluation values for each object are recorded. That is, the frequency spectra and sensory evaluation values of a plurality of objects are recorded as a database.

Then, in the frequency spectrum, a frequency band in which a high correlation is shown between the spectral intensity and the sensory evaluation value is determined. In that case, for example, the average value of the power spectrum density is determined every 10 Hz, and a correlation analysis between this average value and the above-mentioned sensory evaluation value is performed. Then, the obtained correlation coefficient extracts a significant value at a significant level of 5%.

A predetermined frequency band showing a high correlation between the spectral intensity in the frequency spectrum of vibration and the sensory evaluation value of tactile sensation may be 5 to 500 Hz, and may be 10 to 400 Hz. If the tactile sensation is a "roughness tactile sensation", a predetermined frequency band showing a high correlation may be 20-350 Hz. If the tactile sensation is a "dry/wet tactile sensation," the predetermined frequency band that exhibits a high correlation may be 50 to 400 Hz.

In this way, if the frequency band with a high correlation between the sensory evaluation value of a given tactile sensation and the power spectral density is determined in advance, the frequency spectrum of skin whose tactile sensation is unknown can be obtained and the frequency band with a high correlation can be obtained. The sensory evaluation value can be estimated by comparing the power spectral density of the data with the database.

(2. Comprehensive tactile evaluation of multiple evaluation items)
When evaluating the overall tactile sensation that combines two or more evaluation items, conventional methods require evaluating a large number of evaluation items, and furthermore, it is necessary to perform arithmetic processing on the evaluation values obtained from those multiple evaluations. It was a time-consuming process to perform. In contrast, the present inventor has found that the "roughness tactile sensation" and "dry/wet tactile sensation" as comprehensive tactile sensations are correlated with the magnitude in a predetermined frequency band of vibrations generated by the skin and the contact object. In addition, we have found that the frequency band that has a high correlation with the sensory evaluation of "roughness to the touch" and the frequency band that has a high correlation with the sensory evaluation of "wet and dry texture" are different.

"Roughness tactile sensation" and/or "dry/wet tactile sensation" as a comprehensive tactile sensation can be determined by performing sensory evaluation on multiple general evaluation items for evaluating skin condition (characteristics), and using multiple data. It can be said that this is a new evaluation item obtained by aggregating the following. Principal component analysis, factor analysis, etc. can be used to aggregate such data.

For example, when principal component analysis is performed on data, "roughness tactile sensation" as the overall tactile sensation and "dry/wet tactile sensation" as the overall tactile sensation can be the first principal component and the second principal component, respectively. Therefore, by finding in advance a frequency band that has a high correlation between the spectral intensity of the frequency spectrum obtained as described above and the score of the principal component, and obtaining at least one frequency spectrum for skin whose tactile sensation is unknown, the correlation between The principal component score can be estimated by comparing the spectral intensity in the high frequency band with the database. Then, for skin conditions whose tactile sensation is unknown, at least one of a tendency regarding roughness and a tendency regarding dryness and humidity can be evaluated.

A predetermined frequency band showing a high correlation between the spectral intensity in the vibration frequency spectrum and the sensory evaluation value of "roughness tactile sensation" as a comprehensive tactile sensation may be 160 to 290 Hz. Further, a predetermined frequency band showing a high correlation between the spectral intensity in the vibration frequency spectrum and the sensory evaluation value of "dry/wet touch" as a comprehensive touch may be 60 to 200 Hz.

Using an evaluation device as shown in FIG. 2, vibration detection and analysis and skin tactile evaluation were performed.

(1. Vibration detection and analysis)
A 3-axis acceleration sensor (manufactured by Tech Gihan Co., Ltd., model: A3AX) was attached to the nail side of the middle finger of one hand of the subject, and while the ventral side of the middle finger was in contact with the surface of one cheek of the subject. , while applying constant pressure, the face was moved back and forth in the left and right direction. The reciprocating motion was performed within a range of 6 cm in the left and right direction of the face at a speed of 60 reciprocations/1 minute. The vibrations caused by this movement were detected by the acceleration sensor mentioned above.

The detected vibrations were converted into electrical signals and sent to analysis means 30 (FIG. 2). The analysis means 30 analyzed the vibration signal and acquired a frequency spectrum as shown in FIG. 3B.

The above vibrations were detected and analyzed for each of the skins of a total of 27 subjects, and frequency spectra were obtained for each.

(2. Sensory evaluation)
Regarding the skin of the 27 subjects mentioned above, they were evaluated as ``smooth'', ``rough'', ``smooth'', ``smooth'', ``heavy'', ``moist'', ``bumpy'', ``surface softness'', and ``inner layer''. A specialized panel conducted a sensory evaluation of the tactile sensation in 10 evaluation items: "softness" and "elasticity." The sensory evaluation value was set on a 5-level scale from 1 to 5.

(3. Correlation between power spectral density and tactile sensation)

(3-1. Touch feel as an independent evaluation item)
Using the frequency spectrum obtained as described above, the correlation between the power spectral density (unit: dB/Hz) and the sensory evaluation value (unit: -) of a predetermined single evaluation item was investigated. In each frequency spectrum, the average value of the power spectrum density was determined every 10 Hz, and a correlation analysis between the average value and the above sensory evaluation value was performed.

Regarding the evaluation items "smooth", "roughness", "smooth", "smooth", "crusty", "moist", "uneven", and "surface softness", power spectral density and sensory evaluation value It was found that there was a relatively high correlation between the two.

Figures 4A to 4D are graphs showing, for each frequency, the correlation coefficient between the power spectral density and the sensory evaluation value for the individual evaluation items of "smooth," "smooth," "bumpy," and "roughness." shows. In this example, a significance test is performed and correlation coefficients that are significant at a significance level of 5% are displayed.

From FIGS. 4A to 4D, it was found that there was a correlation between the power spectral density and the sensory evaluation value in each predetermined frequency band for the tactile sensation of each evaluation item. For example, as shown in Figure 4A, the correlation between the power spectral density and the sensory evaluation value is high in the frequency band of 100 to 370 Hz for the tactile sensation of "smooth" (an independent evaluation item regarding skin roughness). Ta. Furthermore, as shown in FIG. 4B, the tactile sensation of the evaluation item "smoothness" (an independent evaluation item regarding skin dryness and moisture) was high in the frequency band of 60 to 250 Hz.

Therefore, the relationship between frequency spectra and sensory evaluation values for the skin of multiple subjects is stored as a database, and frequency spectra for skin whose sensory evaluation is unknown are obtained under the same conditions and compared against the database. By comparing the power spectral densities in predetermined frequency bands, it is possible to accurately evaluate the tactile sensation of unknown skin, especially the tactile sensation related to skin roughness or dryness and wetness.

(3-2. Overall tactile sensation)
Principal component analysis was performed on the data of the 27 sensory evaluation values for the skin performed in "2. Sensory evaluation." The results are shown in FIG. In FIG. 5, the horizontal axis is the first principal component score, and the vertical axis is the second principal component score.

Figure 6A shows the coefficients (principal component loading) of each evaluation item when calculating the first principal component score (roughness tactile score), and Figure 6B shows the second principal component score (dry/wet tactile score). The coefficients (principal component loadings) of each evaluation item when calculated are shown. As shown in Figure 6A, the evaluation items that have a high correlation with the first principal component are "smooth," "rough," "smooth," "crusty," and "bumpy." It can be seen that this is the main component that comprehensively represents the tactile sensation. In addition, as shown in Figure 6B, the evaluation items that have a high correlation with the second principal component are "smooth" and "moist," so the second principal component is the main component that comprehensively expresses the dry and wet texture. I understand.

Next, using the 27 frequency spectra obtained as described above, we determined the power spectral density (unit: dB/Hz) and the main effect of "roughness tactile sensation" as a comprehensive tactile sensation that takes into account multiple evaluation items. We investigated the correlation with component scores (unit: -).

FIG. 7A shows a graph showing the correlation coefficient between the roughness tactile sensation (first principal component) score and the power spectral density for each frequency. As shown in FIG. 7A, for "roughness tactile sensation", it was found that the correlation between power spectral density and score was particularly high in the frequency band of 160 to 290 Hz.

Similarly, the correlation between the power spectral density (unit: dB/Hz) and the principal component score (unit: -) of "dry/wet tactile sensation" as a comprehensive tactile sensation considering a plurality of evaluation items was investigated.

FIG. 7B shows a graph showing the correlation coefficient between the dry/wet touch (second principal component) score and the power spectral density for each frequency. As shown in FIG. 7B, for "roughness tactile sensation", it was found that the correlation between power spectral density and score was particularly high in the frequency band of 60 to 200 Hz.

In this way, it would be possible to obtain a frequency spectrum by detecting the vibrations generated by relative movement between the skin and a contact object at least once, even for comprehensive tactile sensation that aggregates a large number of evaluation items. By comparing the magnitude of vibration in a predetermined frequency band with respect to a database acquired in advance, the tactile sensation of unknown skin can be evaluated.

This application claims priority based on Japanese Patent Application No. 2018-195132 filed with the Japan Patent Office on October 16, 2018, the entire contents of which are incorporated herein by reference.

10 Skin evaluation device 20 Vibration detection means 30 Analysis means 40 Evaluation means S Subject

Claims (9)

Detects vibrations generated by relative movement between the skin and the contact object while making contact,
frequency-analyzing the vibration to obtain a frequency spectrum;
Based on the spectral intensity in a predetermined frequency band of the frequency spectrum, in light of the relationship between the spectral intensity in the predetermined frequency band and the sensory evaluation of the overall tactile sensation of skin roughness , which has been determined in advance, including evaluating the overall tactile feel of the roughness of the
The above relationship is
Frequency analysis of vibrations generated by relative movement between the skin of multiple subjects and a contact object while in contact with each other is performed to obtain frequency spectra.
For each of the plurality of subjects, obtain sensory evaluation data for a plurality of skin texture evaluation items including the texture of skin roughness and the texture of dryness and wetness of the skin,
Performing principal component analysis on the data of the sensory evaluation to obtain a principal component score corresponding to the sensory evaluation of the overall tactile sensation of skin roughness,
Determining the correlation between the spectral intensity of the frequency spectrum and the principal component score for each frequency,
Find the frequency band with high correlation,
A skin evaluation method (however, excluding medical procedures) , which is obtained by obtaining a relationship between spectral intensity in the frequency band and a sensory evaluation of a comprehensive tactile sensation of the skin roughness . The skin evaluation method according to claim 1, wherein the predetermined frequency band is 160 to 290 Hz. Detects vibrations generated by relative movement between the skin and a contact object while in contact,
Frequency analysis of the vibration to obtain a frequency spectrum;
Based on the spectral intensity in a predetermined frequency band of the frequency spectrum, in light of the predetermined relationship between the spectral intensity in the predetermined frequency band and the sensory evaluation of the overall tactile sensation of dryness and wetness of the skin, Including evaluating the overall dry and wet tactile sensation ,
The above relationship is
Frequency analysis is performed on each vibration generated by relative movement between the skin of multiple subjects and a contact object while making contact, and a frequency spectrum is obtained.
For each of the plurality of subjects, obtain sensory evaluation data for a plurality of skin texture evaluation items including the texture of skin roughness and the texture of dryness and wetness of the skin,
Performing a principal component analysis on the data of the sensory evaluation and obtaining a principal component score corresponding to the sensory evaluation of the overall tactile sensation of dryness and wetness of the skin,
Determining the correlation between the spectral intensity of the frequency spectrum and the principal component score for each frequency,
Find the frequency band with high correlation,
A skin evaluation method (excluding medical procedures) that is obtained by obtaining a relationship between the spectral intensity in the frequency band and a sensory evaluation of the comprehensive tactile sensation of dryness and wetness of the skin . The skin evaluation method according to claim 3, wherein the predetermined frequency band is 60 to 200 Hz. 4. The spectral intensity is expressed as an index value obtained from one or more of an integral value, a centroid value, an average value, a median value, and a maximum value of a power spectral density in the predetermined frequency band. skin evaluation method. a detection means for detecting vibrations generated by relative movement between the skin and the contact body while making contact with the body;
analysis means for frequency-analyzing the vibration to obtain a frequency spectrum;
Based on the spectral intensity in a predetermined frequency band of the frequency spectrum,
an evaluation means for evaluating the overall tactile sensation of the skin roughness in light of the relationship between the spectral intensity in the predetermined frequency band and the sensory evaluation of the overall tactile sensation of the skin roughness, which has been determined in advance. Equipped with
The above relationship is
Frequency analysis of vibrations generated by relative movement between the skin of multiple subjects and a contact object while in contact with each other is performed to obtain frequency spectra.
For each of the plurality of subjects, obtain sensory evaluation data for a plurality of skin texture evaluation items including the texture of skin roughness and the texture of dryness and wetness of the skin,
Performing principal component analysis on the data of the sensory evaluation to obtain a principal component score corresponding to the sensory evaluation of the overall tactile sensation of skin roughness,
Determining the correlation between the spectral intensity of the frequency spectrum and the principal component score for each frequency,
Find the frequency band with high correlation,
A skin evaluation device that obtains a relationship between a spectral intensity in the frequency band and a sensory evaluation of a comprehensive tactile sensation of the roughness of the skin . a detection means for detecting vibrations generated by relative movement between the skin and the contact body while making contact with the body;
analysis means for frequency-analyzing the vibration to obtain a frequency spectrum;
Based on the spectral intensity in a predetermined frequency band of the frequency spectrum,
evaluation means for evaluating the overall tactile sensation of the dry and wet skin in light of the relationship between the spectral intensity in the predetermined frequency band and the sensory evaluation of the overall tactile sensation of the dry and wet skin. ,
The above relationship is
Frequency analysis is performed on each vibration generated by relative movement between the skin of multiple subjects and a contact object while making contact, and a frequency spectrum is obtained.
For each of the plurality of subjects, obtain sensory evaluation data for a plurality of skin texture evaluation items including the texture of skin roughness and the texture of dryness and wetness of the skin,
Performing a principal component analysis on the data of the sensory evaluation and obtaining a principal component score corresponding to the sensory evaluation of the overall tactile sensation of dryness and wetness of the skin,
Determining the correlation between the spectral intensity of the frequency spectrum and the principal component score for each frequency,
Find the frequency band with high correlation,
A skin evaluation device that obtains a relationship between a spectrum intensity in the frequency band and a sensory evaluation of a comprehensive tactile sensation of dryness and humidity of the skin . A method for determining a relationship used for evaluating skin texture, the method comprising:
Frequency analysis of vibrations generated by relative movement between the skin of multiple subjects and a contact object while in contact with each other is performed to obtain frequency spectra.
For each of the plurality of subjects, obtain sensory evaluation data for a plurality of skin texture evaluation items including the texture of skin roughness and the texture of dryness and wetness of the skin,
Performing a principal component analysis on the data of the sensory evaluation, obtaining a principal component score corresponding to the sensory evaluation of the overall texture of the skin roughness,
Determining the correlation between the spectral intensity of the frequency spectrum and the principal component score for each frequency,
Find the frequency band with high correlation,
A method comprising obtaining a relationship between spectral intensity in the frequency band and a sensory evaluation of the overall skin texture of the skin roughness . A method for determining a relationship used for evaluating skin texture, the method comprising:
Frequency analysis of vibrations generated by relative movement between the skin of multiple subjects and a contact object while in contact with each other is performed to obtain frequency spectra.
For each of the plurality of subjects, obtain sensory evaluation data for a plurality of skin texture evaluation items including the texture of skin roughness and the texture of dryness and wetness of the skin,
Performing a principal component analysis on the data of the sensory evaluation, obtaining a principal component score corresponding to the sensory evaluation of the overall dry and wet texture of the skin,
Determining the correlation between the spectral intensity of the frequency spectrum and the principal component score for each frequency,
Find the frequency band with high correlation,
A method comprising obtaining a relationship between spectral intensity in the frequency band and an overall dry/wet sensation of the skin .

Images