JP7776235B2 - Application pressure evaluation method, application pressure evaluation system, and method for setting appropriate range in application pressure evaluation system - Google Patents

Description

The present invention relates to an application pressure evaluation method for evaluating the application pressure when a user applies cosmetics to the face with their hands, an application pressure evaluation system equipped with an application pressure measuring device and an information processing device, and a method for setting an appropriate range in an application pressure evaluation system.

Recently, Non-Patent Document 1 has proposed that the emotions evoked by touch differ between hairless parts of the human body, such as the fingers, palms, and soles, and hairy parts, such as the arms and face, and that stroking hairy parts with a specific pressure and speed evokes a pleasant feeling of comfort.

Furthermore, Patent Document 1 discloses that stroking the arm with appropriate pressure and speed evokes a pleasant feeling, which improves the texture of the skin.

However, the appropriate stroking sensations described in Non-Patent Document 1 and Patent Document 1 were achieved by strokes operated by a fixed external device, not by human hands. As a result, even if it was found that they evoked positive emotions, it was difficult to reproduce them on one's own. Furthermore, evaluations in these experiments involved taking samples such as blood from the subjects, which made real-time evaluation impossible.

On the other hand, in order to detect finger movement and measure pressure strength, configurations have been disclosed in which a tactile detection unit is provided over the entire palm, as shown in Figure 1A (Patent Document 2), a configuration in which sensors are provided on the fingertips, as shown in Figure 1B (Patent Document 3), and a configuration in which sensors are provided on the upper and side surfaces of the fingers, as shown in Figure 1C (Patent Document 4).

Furthermore, Patent Document 5 proposes making the sensor into a conductive film and using it as a flexible sensor device for the body surface that can be worn on the hand or other part of the body.

Japanese Patent Application Laid-Open No. 2019-105619 Japanese Patent Application Laid-Open No. 2008-032511 Re-table 2017/175868 publication JP 2013-003782 A Patent No. 6292665

Coding of pleasant touch by unmyelinated afferents in humans/ Volume 12/number 5/May 2009 natural neuroscience

However, in the configurations of Patent Documents 2 to 4 and Patent Document 5 shown in Figures 1A to 1C, the sensors are placed directly on the fingers or hands. Therefore, for example, if one wears one of these sensors on their hand and strokes the skin of a person's face or other area that has hair in order to evoke a pleasant feeling, contact with the sensor will induce an unpleasant sensation in the skin at that point of contact.

Furthermore, if the sensor is made into a film and attached to the surface of the hand, as in Patent Document 5, and this sensor is used to evaluate contact when applying cosmetics, etc., there is a risk that the film that makes up the sensor will dissolve depending on the ingredients of the cosmetics used.

In view of the above circumstances, the present invention aims to provide an application pressure evaluation method that can evaluate the pressure applied to the face by fingertips or hands in real time without installing sensors on the fingertips or hands.

In order to solve the above problem, one aspect of the present invention is an application pressure evaluation method that includes a detection step in which a measuring device attached to the user's upper arm, forearm, or wrist is used to detect the application pressure when the user applies cosmetics to the face with their hand by measuring changes in the measurement value; a comparison step in which a value calculated from the detected measurement value is compared to determine whether it is within an appropriate range; and a notification step in which the user is notified whether the value calculated from the measurement value is within or outside the appropriate range.

According to one aspect, an application pressure evaluation method allows for real-time evaluation of pressure applied to the face by fingertips or hands without the need for sensors on the fingertips or hands.

FIG. 10 is a diagram showing an example of a sensor for measuring pressure and movement of a fingertip or hand in a conventional example. FIG. 10 is a diagram showing an example of a sensor for measuring pressure and movement of a fingertip or hand in a conventional example. FIG. 10 is a diagram showing an example of a sensor for measuring pressure and movement of a fingertip or hand in a conventional example. FIG. 1 is a schematic diagram of a coating pressure evaluation system according to a first embodiment. FIG. 2 is a functional block diagram of the application pressure evaluation system according to the first embodiment. 10 is a flowchart showing a process for evaluating the application pressure to the face when using the application pressure evaluation system according to the first embodiment. 10A to 10C are diagrams illustrating an example of a pressing method when setting an appropriate range used in the application pressure evaluation flow according to the first embodiment. FIG. 10 is a functional block diagram of the analysis system when setting an appropriate range used in the application pressure evaluation flow according to the first embodiment. 10 is a measurement and analysis flowchart for setting an appropriate range in the coating pressure evaluation system according to the first embodiment. This is a table showing the RMS change rate of the myoelectric potential amplitude, the subject's subjective impression, cheek moisture content, and moisture evaporation rate when multiple subjects pressed their faces with three strengths: weak, normal, and strong. FIG. 10 is a diagram showing the correlation between the RMS change rate of the forearm myoelectric potential amplitude and comfort level when using a variety of pressing strengths. FIG. 10 is a diagram showing the distribution of the number of people when an appropriate range is set. FIG. 10 is a diagram showing the correlation between preference and the RMS change rate of the forearm myoelectric potential amplitude when performing presses at different intensities. FIG. 10 is a diagram showing the distribution of the number of people when an appropriate range is set. FIG. 10 is a graph showing the correlation between the RMS change rate of the forearm myoelectric potential amplitude when pressing with normal strength and the moisture content of the cheek. FIG. 10 is a graph showing the correlation between the RMS change rate of the forearm myoelectric potential amplitude when pressing with normal strength and the amount of moisture loss from the cheek. 10A to 10C are diagrams illustrating hand movements in an example of the stroke method when setting an appropriate range used in the application pressure evaluation flow according to the first embodiment. FIG. 10 illustrates an example of a hand pressure trajectory on the face. FIG. 10 is a diagram showing the correlation between the RMS change rate of the myoelectric potential amplitude of the forearm and the amount of moisture loss from the cheek when a cosmetic material is applied by the stroke method. FIG. 10 is a diagram showing the RMS rate of change in myoelectric potential amplitude over time when a cosmetic material is applied alone and when a beauty serum is applied and then a cosmetic material is applied, using the stroke method. FIG. 10 is a diagram showing the average value of the RMS rate of change over the entire application time when a cosmetic material is applied alone and when a cosmetic material is applied after a beauty serum is applied, using the stroke method. FIG. 1 is a schematic diagram illustrating an application pressure evaluation system according to a first embodiment when used by an individual. FIG. 10 is a schematic diagram illustrating a case where a beauty professional uses the application pressure evaluation system according to the first embodiment to instruct a customer on application pressure. 1 is a schematic diagram illustrating a case where a professional beauty instructor is instructing beauty staff using the application pressure evaluation system according to the first embodiment. FIG. FIG. 10 is a schematic diagram of a coating pressure evaluation system according to a second embodiment. FIG. 10 is a functional block diagram of an application pressure evaluation system according to a second embodiment. 10 is a flowchart showing a process for evaluating the application pressure to the face when using the application pressure evaluation system of the second embodiment. This is the acceleration waveform when pressing with normal force. This is the acceleration waveform when pressing with about half the usual force. This is the acceleration waveform when pressing with twice the usual force. This is the acceleration waveform when pressing with the most comfortable force. This is the frequency power spectrum when pressing with normal force. This is the frequency power spectrum when pressing with about half the usual force. This is the frequency power spectrum when pressing with about twice the usual force. This is the frequency power spectrum when pressing with the most comfortable force.

The following describes an embodiment of the present invention with reference to the drawings. In the drawings, identical components are designated by the same reference numerals, and duplicate explanations may be omitted.

The present invention relates to an application pressure evaluation method for evaluating the application pressure when a user applies cosmetics to the face with their hands, an application pressure evaluation system equipped with an electromyometer and an information processing device, and a method for setting an appropriate range in the application pressure evaluation system.

[First embodiment]
<Schematic configuration of application pressure evaluation system>
First, the coating pressure evaluation system 10 according to the first embodiment will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a schematic diagram of the coating pressure evaluation system 10 according to the first embodiment. Fig. 3 is a functional block diagram of the coating pressure evaluation system 10 according to the first embodiment.

In the first embodiment, the application pressure is measured using an electromyograph. The application pressure evaluation system 10 according to the first embodiment includes an electromyograph 1 and an information processing device 2. In this embodiment, an example is described in which the electromyograph 1 is used as the measuring device to detect the application pressure based on changes in the myoelectric potential (measured value), but the measuring device and measured value are not limited to this.

As shown in Figure 2, electromyograph (EMG) 1 is attached to the user's forearm and detects the application pressure when the user applies cosmetics to their face with their hand by measuring changes in the myoelectric potential of the forearm. As shown in Figure 2, electromyograph 1 is preferably attached to the inside of the forearm, near the pronator teres or palmaris longus muscle, near the inner elbow crease. The pronator teres or palmaris longus muscle of the forearm are areas where myoelectric potential changes in response to movement of the hand (the part from the wrist to the fingertips).

The information processing device 2 is capable of communicating with the electromyograph 1, acquiring myoelectric potentials from the electromyograph 1, and evaluating and reporting the application pressure based on the myoelectric potentials. This information processing device 2 is an information processing terminal for evaluation, and is capable of outputting audio and/or images, such as a smartphone, tablet, mobile phone, or laptop. Alternatively, it may be an information processing terminal dedicated to this application pressure evaluation system 10. The information processing device 2 shown in Figure 2 is an information processing device for evaluation.

In addition, in the application pressure evaluation system 10, a speaker, projector, etc. may be connected to the information processing device 2, in which case the notification function may be performed by audio from the speaker or a projected image from the projector.

Communication between the information processing device 2 and the electromyograph 1 is achieved, for example, via Bluetooth (registered trademark), infrared communication, Wi-Fi (registered trademark), etc.

As shown in FIG. 3, the information processing device 2 has an electromyography acquisition unit 21, an RMS calculation unit 22, a resting RMS value temporary storage unit 23, an RMS change rate calculation unit 24, an appropriate range storage unit 25, a comparison unit 26, an audio output unit 27, and a display unit 28. The audio output unit 27 and the display unit 28 together constitute a notification unit 29.

The myoelectric potential acquisition unit 21 is an acquisition unit that acquires the myoelectric potential, and acquires the myoelectric potential measured by the electromyograph 1 via communication.

After acquiring the myoelectric potential, the RMS calculation unit 22 calculates the root mean square (RMS) of the amplitude of the myoelectric potential.

The resting RMS value temporary memory unit 23 temporarily stores the RMS of the amplitude of the myoelectric potential at rest.

After acquiring the myoelectric potential during application, the RMS change rate calculation unit 24 calculates the rate of change in the RMS of the myoelectric potential amplitude compared to the RMS of the myoelectric potential amplitude at rest. Because the amplitude in an electromyogram (EMG) is a relative value, by using the RMS change rate (%) (ΔRMS) during application relative to the RMS value at rest, it is possible to treat such types of electromyographs equally. The RMS calculation unit 22 and the RMS change rate calculation unit 24 are calculation units.

The appropriate range memory unit 25 is a memory unit that stores the appropriate range of the RMS change rate in advance.

The comparison unit 26 compares whether the RMS change rate calculated from the acquired myoelectric potential is within an appropriate range.

Based on the comparison results from the comparison unit 26, the notification unit 29 notifies whether the RMS change rate of the myoelectric potential, which is the value calculated from the acquired myoelectric potential, is within or outside the appropriate range.

When notifying by voice, the voice output unit 27 notifies by voice whether the RMS rate of change of the detected myoelectric potential is within or outside the appropriate range. In the case of voice, the notification may be given only when the RMS rate of change is outside the appropriate range, or only when it is within the appropriate range.

When notifying by display, the display unit 28, for example, a display, displays the RMS change rate (%) of the amplitude of the myoelectric potential and the appropriate range value superimposed on each other. The display may be, for example, a liquid crystal display panel, an organic EL (Electro-luminescence) or OLED (Organic Light Emitting Diode) display panel, etc.

In addition, the notification unit 29 may combine visual and audio notifications.

The functions of the RMS calculation unit 22, resting RMS value temporary storage unit 23, RMS change rate calculation unit 24, appropriate range storage unit 25, and comparison unit 26 in the information processing device 2 are incorporated into a program such as an app, and can be executed by launching the app.

In addition, although not shown in the figure, the information processing device 2 also includes electronic components, such as a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), input/output interface, and internal bus, which perform information processing related to basic operations.

(Application pressure evaluation flow)
2 to 4, a method for evaluating application pressure in the application pressure evaluation system 10 will be described. Fig. 4 shows a flow for evaluating application pressure to the face when the application pressure evaluation system according to the first embodiment is used.

In S1, as preparation, the app on the information processing device 2 is launched and the electromyograph 1 is attached to the user's forearm. At this time, the electromyograph 1 measures the myoelectric potential at rest and transmits it to the information processing device 2.

In S2, the information processing device 2 calculates the RMS value of the muscle potential at rest.

At S3, the user begins applying cosmetics to their face using their hands.

In S4, the electromyograph 1 measures the myoelectric potential of the forearm and transmits the measured myoelectric potential in real time to the information processing device 2.

In S5, the calculation units 22 and 24 of the information processing device 2 calculate the RMS rate of change of the amplitude of the acquired myoelectric potential. This is the detection step.

In S6, the comparison unit 26 of the information processing device 2 compares the RMS change rate of the amplitude of the myoelectric potential with the stored appropriate range (comparison step).

In S7, strength information based on the comparison result of the RMS change rate against the appropriate range is notified (notification step).

Then, S3 to S7 are repeated until application of the cosmetics to the face is completed in S8.

Once the application of cosmetics to the face is completed in S8, the electromyograph 1 is removed from the forearm in S9, and the flow ends.

In this way, the electromyograph is attached to the user's forearm, making it possible to evaluate in real time the pressure applied to the face by the fingertips or hand without the need for sensors on the fingertips or hand. Therefore, because the hand is free during the evaluation, the user can carry out the usual application method and evaluation without having to worry about contact between the sensor and the face.

The appropriate range used for the comparison in S6 of Figure 4 to evaluate the strength of pressure when applying cosmetics to the face is set in advance through experiments with multiple subjects. Below, we will explain how to set the appropriate range for the application pressure evaluation system.

<Pressing method>
Common cosmetic application methods include the pressing method and the stroke method. First, the pressing method will be described.

Figure 5 shows an example of the pressing method when setting the appropriate range used in the application pressure evaluation flow according to the first embodiment. The pressing method, as shown in Figure 5, is a method of applying pressure at the same position without moving. Note that with the pressing method, the cheeks of the face are pressed multiple times for several seconds (a predetermined time), and the pressing position on the face may be changed, but when moving the pressing position, no force should be applied to the face.

The appropriate range for this pressing method is explained below. When applying pressure without moving, there is no friction due to movement, so the pressing method remains the same whether or not cosmetics are used. Therefore, the following experiments were analyzed without using cosmetics.

<Analysis system and flow>
FIG. 6 is a functional block diagram of an analysis system when setting an appropriate range used in the application pressure evaluation flow according to the first embodiment.

The analysis system 20 has an electromyograph 1 and an analytical information processing device 3. Below, an example is described in which the analytical information processing device 3 is an analytical information processing device with a separate configuration from the above-mentioned evaluation information processing device 2, but the functions of the evaluation information processing device 2 and the analytical information processing device 3 may also be integrated into a single information processing device.

It is preferable that the electromyograph 1 is the same type as the electromyograph used by the user shown in Figure 2, for example, but as the RMS rate of change is used for the calculation as described above, a different type of electromyograph may also be used.

The analytical information processing device 3 has an electromyography acquisition unit 311, an RMS calculation unit 312, a resting RMS value temporary storage unit 313, an RMS change rate calculation unit 314, an RMS change rate storage unit 315, a subject information acquisition unit 321, a correlation analysis unit 322, an appropriate range setting unit 323, an appropriate range accumulation unit 324, and a transmission unit 325.

The myoelectric potential acquisition unit 311, RMS calculation unit 312, resting RMS value temporary storage unit 313, and RMS change rate calculation unit 314 in the analytical information processing device 3 have the same functions as the myoelectric potential acquisition unit 21, RMS calculation unit 22, resting RMS value temporary storage unit 23, and RMS change rate calculation unit 24 in the above-mentioned information processing device 2. Note that while the evaluation information processing device 2 calculates the RMS change rate for the myoelectric potential from one electromyograph 1, the analytical information processing device 3 calculates the RMS change rate for each of multiple individuals based on multiple myoelectric potentials measured by multiple electromyographs 1 attached to multiple subjects.

The RMS change rate memory unit 315 stores the RMS change rate calculated by the RMS change rate calculation unit 314 for each person and strength.

The subject information acquisition unit 321 acquires the subject's emotional information evaluation values (comfort, likes and dislikes) before, during, and/or after pressing, as well as the subject's measurement information (skin moisture content, skin moisture loss (transepidermal water loss (TEWL))). The subject information acquisition unit 321 is a communication unit, and if the communication method is the same, it may be realized by the same communication component as the myoelectric potential acquisition unit 311.

The correlation analysis unit 322 associates the correlation between the strength of the pressure applied to the face and the evaluation value or measurement information of the emotional information.

The appropriate range setting unit 323 sets an appropriate range for the RMS rate of change based on the associated correlation. Note that the appropriate range may have upper and lower limits, or only an upper limit or only a lower limit may be set.

The appropriate range storage unit 324 stores the appropriate range of the set RMS change rate.

The transmitting unit 325 outputs the stored appropriate range of the RMS change rate. Note that information on the appropriate range may be output as software or an app together with the calculation method, or the appropriate range of the RMS change rate may be output alone. For example, if the population of subjects increases, it may be possible to update only the appropriate range of the RMS change rate alone. Note that the transmitting unit 325 is a communication unit, and if the communication method is the same, it may be realized by the same communication component as the electromyography acquiring unit 311 and/or the subject information acquiring unit 321. Alternatively, it may be stored in the appropriate range storage unit 324 and made available to the user by accessing a server.

(Proper range setting flow)
7 is a measurement and analysis flowchart for setting an appropriate range in the coating pressure evaluation system according to the first embodiment. In order to set an appropriate range for the press method, data was obtained from eight subjects (No. 1 to No. 8) in their 30s and 40s as shown in FIG. 8 below.

In S201 of Figure 7, the software of the information processing device 3 is launched and an electromyograph is attached to the forearm of each of the multiple subjects. The electromyograph 1 measures the myoelectric potential at rest and transmits it to the analytical information processing device 3. In the actual measurements for analysis, a wireless myoelectric potential sensor manufactured by Oisaka Electronics was used as the electromyograph 1.

In S202, the information processing device 3 calculates the RMS value of the resting myoelectric potential of each subject.

In S203, the subject begins pressing their face as if they were applying regular cosmetics. In this experiment, pressing their face involved pressing their cheeks with their hands for five seconds, repeated five times.

In S204, the electromyograph 1 measures the myoelectric potential of the forearm during the press and transmits the myoelectric potential to the analytical information processing device 3. In the analysis flow, the myoelectric potential may be transmitted from the electromyograph 1 to the analytical information processing device 3 in real time during the press, or may be transmitted all at once after the press.

In S205, the analytical information processing device 3 calculates the RMS change rate of the amplitude of the forearm's myoelectric potential during pressing.

At S206, the subject stops pressing their hands against their face with their usual force.

In S207, the skin moisture content and water evaporation rate (transepidermal water loss: TEWL) of each subject's cheek are measured. Here, skin moisture content is measured using a Corneometer (registered trademark) C825 (manufactured by Courage+Khazakaelectronic GmbH, Germany) as a skin moisture meter, and transepidermal water evaporation rate TEWL is measured using a portable water evaporation meter VapoMeter (registered trademark) (manufactured by Delfin Technologies, Finland) as a water evaporation rate meter. The measurement information is then sent to the analytical information processing device 3.

In S208, the RMS change rate of the myoelectric potential amplitude of each subject's forearm measured and calculated in S205 is correlated with the skin moisture content measured in S207.

In S209, the RMS change rate of the myoelectric potential amplitude of each subject's forearm measured and calculated in S205 is correlated with the amount of water evaporation from the skin measured in S207.

In S210, specify a weak pressure strength and begin pressing the face. When pressing the face in S210, press the cheek with your hand five times in five seconds using a weaker force than usual.

In S211, the electromyograph 1 measures the myoelectric potential of the forearm during pressing, and the myoelectric potential is transmitted to the analytical information processing device 3.

In S212, the analytical information processing device 3 calculates the RMS rate of change of the forearm myoelectric potential amplitude.

Then, in S214, specify the pressure strength as "strong" and begin pressing on the face. When pressing on the face in S214, press the cheek with your hand five times in five seconds with a stronger force than usual.

Then, returning to S211, the analytical information processing device 3 calculates the RMS change rate of the forearm myoelectric potential amplitude for each person for the ``strong'' pressing method as well, and calculates the RMS change rate of the forearm myoelectric potential amplitude in S212.

Once the pressing at the three different strengths (normal, strong, weak) is completed (Yes in S213), in S215, each of the multiple subjects evaluates the facial sensation for each pressure strength (comfort, preference (whether they like it)), and the analytical information processing device 3 acquires the evaluation value.

In S216, the analytical information processing device 3 correlates the RMS change rate of the measured and calculated forearm myoelectric potential amplitude with the evaluation value.

In S217, the threshold (upper and lower limits) of the appropriate range of the RMS of the forearm myoelectric potential amplitude is calculated and set based on the correlation with the skin moisture content calculated in S208, the correlation with the skin moisture evaporation rate calculated in S209, and/or the correlation with the evaluation value calculated in S216.

In S218, the appropriate threshold set in S217 is stored in the appropriate range storage unit 324 of the analytical information processing device 3, and the flow ends.

In this way, an appropriate range for evaluating application pressure can be set based on the experimental results of multiple subjects. Specific calculations are explained below.

<Experimental Example 1>
Using the procedure shown in Figure 7 above, data was obtained on the RMS change rate of the myoelectric potential amplitude, the subjective evaluation of the subject (comfort, preference), the amount of moisture in the cheeks, and the amount of moisture evaporation from the cheeks when multiple subjects pressed their faces with three different strengths: "weak,""normal," and "strong," as shown in Figure 8.

Note that "normal" pressure refers to the "strength of pressure applied to the face as applied on a daily basis," while "weak" means weaker than "normal" and "strong" means stronger than "normal." Each item will be discussed below.

In steps S203, S210, and S214 of the above flow, electromyographs 1 were attached to the forearms of multiple subjects (e.g., eight people), and the strength of pressure applied to each subject's face with their hands at three different intensities was detected by measuring changes in the forearm myoelectric potential. This allowed the RMS rate of change values of the amplitude of the forearm myoelectric potential at three different intensities to be obtained from the eight people.

Then, in S215, a questionnaire was used to obtain evaluation values for comfort for each of the multiple application pressures from each of the multiple subjects. This resulted in three types of evaluation values for comfort (24 data points) being obtained from eight people. "Comfort" refers to whether or not the sensation was pleasant. As shown in the table in Figure 8, among the three strengths of "weak," "normal," and "strong," the majority of people felt that "normal" was the most comfortable.

The evaluation scores were obtained using the visual analogue scale (VAS), which is advantageous for statistical processing. Participants were asked to draw a line of a specified length for each question item and indicate the level they currently felt. In this study, the results were converted to a maximum of 10 points, so the comfort index, which is one of the evaluation data points for individual impressions, is also expressed as a decimal rather than an integer.

(Correlation with comfort)
9A and 9B are diagrams showing the correlation between the RMS change rate of the forearm myoelectric potential amplitude and comfort level when using the multiple pressing methods shown in FIG. 8.

The analytical information processing device 3 correlates the strength of application pressure (pressure) to the face with the comfort evaluation value, and sets an appropriate range for the RMS change rate of the amplitude of the myoelectric potential corresponding to the strength of application pressure to the face that resulted in a high comfort evaluation value.

In detail, Figure 9A shows the correlation between the RMS change rate of the amplitude of myoelectric potential and comfort, and Figure 9B shows the distribution of the number of people when an appropriate range is set.

In Figure 9A, the horizontal axis shows the RMS rate of change in the amplitude of the myoelectric potential over a 5-second period, and the vertical axis shows the comfort index. In Figure 9B, the horizontal axis shows the number of measurement data points below, within, and above the appropriate range, and the vertical axis shows the comfort index.

As shown in Figure 9A, for example, if the appropriate range for the RMS rate of change of the amplitude of the myoelectric potential is set to 50% to 150%, the comfort index can be made higher within the set appropriate range than outside the appropriate range, as shown in Figure 9B.

(Correlation with preferences)
10A and 10B are diagrams showing the correlation between preference and the RMS change rate of the amplitude of the forearm myoelectric potential obtained by the pressing method of various intensities shown in FIG. 8 .

The method for calculating the correlation between the RMS rate of change in the amplitude of the EMG signal during pressing and preference is the same as in Figures 9A and 9B. "Preference" refers to personal preference, whether or not a particular pressing method is liked or disliked, separate from the feeling of pleasure (comfort). As shown in the table in Figure 8, among the three strengths of "weak," "normal," and "strong," the majority of people felt that "normal" was their favorite.

The analytical information processing device 3 correlates the strength of application pressure (pressure) on the face with the preference evaluation value, and sets an appropriate range with upper and lower limits corresponding to the strength of application pressure on the face with a high preference evaluation value.

Figure 10A shows the correlation between the RMS change rate of the amplitude of myoelectric potential and preference, and Figure 10B shows the distribution of the number of people when an appropriate range is set.

In Figure 10A, the horizontal axis represents the RMS rate of change of the amplitude of the EMG signal, and the vertical axis represents the preference index. In Figure 10B, the horizontal axis represents the number of measurement data points below the appropriate range, within the appropriate range, and above the appropriate range, and the vertical axis represents the preference index.

As shown in Figure 10A, for example, if the appropriate range of the RMS rate of change of the amplitude of the myoelectric potential is set to 50% to 150%, the preference index can be higher within the appropriate range set as shown in Figure 10B than outside the appropriate range.

(Correlation with cheek moisture content)
FIG. 11 is a graph showing the correlation between the RMS change rate of the myoelectric potential amplitude of the forearm and the moisture content of the cheek when performing a normal press.

As shown in S203 to S205 of the flow in Figure 7, electromyograph 1 was attached to the forearms of multiple subjects, and changes in the myoelectric potential of the forearms were detected when each of the multiple subjects pressed their hands with the same strength as when applying cosmetics to their face in the usual manner (with the strength they would use on a daily basis), and the RMS rate of change was calculated.

Then, in S207, the skin moisture content of each subject's cheek was obtained using a corneometer. Note that, because the skin moisture content value is a measured value, it is more objective data than comfort or preference.

This allows us to correlate the strength of the pressure applied to the face on a daily basis with the amount of moisture in the cheeks.

Figure 11 shows the correlation between the RMS change rate of the forearm's myoelectric potential amplitude and the moisture content of the cheek when performing normal pressing. The moisture content of the cheek measured with a corneometer is the amount of moisture contained within approximately 15 μm of the skin surface (mainly the stratum corneum), and the higher the moisture content, the better the skin condition.

As shown in Figure 11, person No. 4, who applies pressure with greater force than the others, with an RMS change rate of 174% of the normal rate, has extremely low cheek moisture content compared to the others. Furthermore, person No. 8, who applies pressure with the second-strongest force, with an RMS change rate of 136%, does not have such low cheek moisture content.

Therefore, taking into consideration the moisture content of the cheeks, it is preferable to set the upper limit of the appropriate range of the RMS change rate of the amplitude of the myoelectric potential to between 136 and 174%, for example, 150% or 160%.

In this way, the analytical information processing device 3 can refer to this result and set an appropriate range for the RMS change rate of the amplitude of the myoelectric potential so that the application pressure is the same as that applied by a subject with high cheek moisture content.

(Correlation with the amount of moisture lost from the cheeks)
FIG. 12 is a diagram showing the correlation between the RMS fluctuation rate of the amplitude of the myoelectric potential when performing normal pressing and the amount of moisture loss from the cheek.

The method for measuring the myoelectric potential of this press is the same as that shown in Figure 11, and the myoelectric potential of the forearm is detected when multiple subjects press with their hands in the usual manner (with the same strength as when applying cosmetics on their face on a daily basis).

Figure 12 shows the correlation between the RMS rate of change in the myoelectric potential amplitude of the forearm and the transepidermal water loss of the cheek. Transepidermal water loss (TEWL) is a value that measures how much moisture escapes from the skin. A low TEWL value means that a small amount of moisture escapes from the skin, while a high TEWL value means that a large amount of moisture escapes from the skin. Therefore, a higher TEWL value is an indicator of suspected skin roughness.

As shown in Figure 12, person No. 4, who presses harder than others, usually at an RMS change rate of 174%, has a higher TEWL than others. And person No. 8, who presses normally at an RMS change rate of 136%, has a higher TEWL than others. Person No. 7, who presses normally at an RMS change rate of 102%, has a high TEWL, but person No. 2, who presses normally at an RMS change rate of 126%, does not have a very high TEWL.

Therefore, from the perspective of cheek TEWL, it is preferable to set the upper limit of the RMS rate of change of the amplitude of the myoelectric potential to, for example, 103 to 135%.

The analytical information processing device 3 can refer to these results and set the appropriate range of the RMS change rate of the amplitude of the myoelectric potential so that the application pressure is the same as that applied by a subject with a small cheek TEWL.

In addition, although an example of setting upper and lower limits has been described for the appropriate range of the RMS change rate defined by the correlation between comfortable and liking in Figures 9 and 10, the appropriate range of the RMS change rate may also be defined by only an upper limit value, as shown in Figures 11 and 12.

Furthermore, the above multiple subjects were in their 30s and 40s, but a 30-year-old and a 49-year-old are expected to have different degrees of aging and different basic skin conditions. While Figures 11 and 12 above illustrate an example of analyzing correlations using raw measurement data, for example, skin moisture content and skin TEWL may be corrected according to age and then analyzed for correlation. Alternatively, the correlations may be analyzed for each subject's skin moisture content and skin TEWL measurements using the relative values of the measurements to the average values for each subject's age.

Furthermore, while the above describes an example in which the setting range is set uniformly, the standard appropriate range may be changed depending on age, skin condition, or other external factors. Examples of skin condition include the presence or absence of rough skin due to seasonal dryness, the presence or absence of acne due to oily skin, and the presence or absence of sunburn. External factors include, for example, the outside temperature and weather (humidity). Personal preferences (preferring strong or weak) may also be reflected somewhat in the appropriate range. Furthermore, as another factor, heart rate may be measured, and the appropriate range for heart rate may be set in addition to the appropriate range for myoelectric potential.

<Stroke method>
The above describes the pressing method, in which pressure is applied from the same position without moving, but some people apply the paint using the stroke method, in which the paint is applied while moving.

Figure 13 shows an example of the stroke method used to set the appropriate range used in the application pressure evaluation flow according to the first embodiment. Figure 13A shows the movement of the hand, and Figure 13B shows an example of the trajectory of hand pressure on the face. In this case, the hand position was moved approximately horizontally (in a fixed direction) relative to the face (cheek), resulting in multiple strokes, and the position where the greatest pressure was applied was gradually shifted vertically as shown by (1) to (4) in Figure 13B.

The following experiment was conducted so that the appropriate range could be determined even when applying using the stroke method. Note that the stroke method, in which pressure is applied while moving, generates friction as the hand moves, and the way the hand moves differs depending on whether or not there is cosmetic product. Therefore, in this experiment, strokes were performed using cosmetic product to obtain results similar to those when applying cosmetic product.

The cosmetic used was a so-called "lotion" that contained oils such as fatty acid esters, which reduce friction. The oils contained in the lotion that reduce friction on the skin may be fatty acid esters, as well as fatty acid ethers, hydrocarbons, silicone oils, fluorine-based oils, etc.

For the stroke method, multiple subjects applied cosmetics to their faces by stroking them in the same way as they normally would, and the electromyography (EMG) was measured and the RMS rate of change in the amplitude of the electromyography was calculated (see S203 to S206 in Figure 7). The amount of transepidermal water loss was then measured (see S207), and correlations were examined (see S209).

Data was collected from nine subjects for the stroke method experiment. Of these subjects, seven were the same as those for the press method, and two were different subjects. In detail, No. 1, No. 2, and No. 3 in Experiment 1 were the same individuals as No. 1, No. 2, and No. 3 in Experiment 2; No. 5 in Experiment 1 was the same individual as No. 4 in Experiment 2; No. 7 and No. 8 in Experiment 1 were the same individual as No. 5 and No. 6 in Experiment 2; and No. 10 in Experiment 1 was the same individual as No. 8 in Experiment 2.

The measurement results of the RMS change rate of the amplitude of the subject's forearm myoelectric potential and the amount of water loss from the cheek (cheek TEWL) when applied using the stroke method are shown in Table 1.

Comparing Table 1 with FIG. 8, it can be seen that when a stroke is performed, the RMS change rate of the amplitude of the myoelectric potential is greater overall than when only a press is performed.

(Amount of moisture lost from cheeks)
FIG. 14 is a diagram showing the correlation between the RMS change rate of the myoelectric potential of the forearm and the amount of moisture evaporation from the cheek when a cosmetic material is applied by the stroke method.

As mentioned above, the lower the transepidermal water loss on the cheek, the better the skin condition. Drawing an approximate line, as in Figure 14, shows that the weaker the pressure, the lower the skin's evaporation rate, and the stronger the pressure, the higher the skin's evaporation rate. This data is distributed close to the approximate line.

Therefore, the analytical information processing device 3 can specify, for example, the appropriate range of RMS change rate to be 400% or less, so as to exclude people with high transepidermal water loss.

(Two types of cosmetics applied)
15A and 15B are diagrams comparing the RMS change rate of the amplitude of myoelectric potential measured by the stroke method when a cosmetic material is applied alone and when a cosmetic material is applied after a beauty serum is applied.

Figure 15A shows the RMS change rate over time, and Figure 15B shows the average RMS change rate over the entire application time.

As shown in Figures 15A and 15B, when applying serum before applying lotion, the application pressure tends to be higher than when applying lotion alone.

Therefore, when applying cosmetics after applying a beauty serum, the upper limit of the appropriate range of the RMS change rate of the myoelectric potential amplitude is set to a value greater than when applying cosmetics alone.

Note that a cosmetic liquid is, for example, a lotion, and a beauty serum is, for example, a booster (lotion introduction), essence, or emulsion. The main difference between a lotion and a beauty serum is viscosity. Compared to a lotion, which has low viscosity like water, a beauty serum generally has a base that is more viscous and thicker. The beauty serum used in this test contains a thickener to give it a medium viscosity, so when the beauty serum is applied, it is thought that friction on the skin is reduced and the skin feels softer.

<Specific example 1 of evaluation system>
FIG. 16 is a schematic diagram of the application pressure evaluation system according to the first embodiment when used by an individual.

The application pressure evaluation system 10A according to the first embodiment can be used as an application for an individual user U to evaluate the pressure applied during daily skin care, as shown in FIG. 16.

In this configuration, as shown in Figure 16, the information processing device 2 is a smartphone S, and by notifying the individual user U by voice, the individual user U can continue to apply cosmetics at an appropriate strength while looking in the mirror M. In addition, the smartphone S may also display the RMS rate of change of the myoelectric potential amplitude along with the appropriate range on the display along with the voice.

In this case, by evaluating the pressure in real time, the individual user U can apply cosmetics appropriately every day, and by applying appropriate application pressure every day, the accumulated damage caused by application can be reduced and skin quality can be improved.

<Specific example 2 of evaluation system>
FIG. 17 is a schematic diagram illustrating a case where a beauty professional uses the application pressure evaluation system according to the first embodiment to instruct a customer on application pressure.

In the application pressure evaluation system 10B according to the first embodiment, as shown in FIG. 17, identical electromyographs 1, 1' are attached to the forearms of a beauty professional, such as beauty advisor B, and customer C. The information processing device 2 (personal computer P) can then visually or audibly instruct customer C so that the same pressure can be reproduced as when beauty advisor B applies a comfortable and appropriate amount of pressure to customer C's face.

As a result, customer C can now reproduce the appropriate pressure applied by beauty advisor B, which would have been difficult for him or her to achieve on his or her own, by having the application pressure evaluation system 10B suggest it.

<Specific example 3 of evaluation system>
FIG. 18 is a schematic diagram showing a case where a beauty instructor T is instructing a beauty student BS using the application pressure evaluation system according to the first embodiment.

In the application pressure evaluation system 10C according to the first embodiment, as shown in Figure 18, identical electromyographs 1, 1' are attached to the forearms of beauty instructor T and beauty student BS. Then, a sample of professional beauty instructor T applying comfortable and appropriate pressure to the face of a person simulating a customer is displayed, and the application pressure data is displayed on the display of information processing device 2 (personal computer P).

The beauty student BS can then reproduce the application pressure by applying pressure similar to the sample values shown. In this way, the application pressure, which is difficult to communicate to others, can be communicated visually or through sound.

In addition, as part of the training for beauty staff, Figure 18 shows an example of pressing the product against the face of a person posing as a customer other than beauty instructor T or beauty student BS, but it is also possible to use the face of beauty student BS to apply application pressure and provide instruction.

The beauty students in this training include, for example, beauty advisor trainees, esthetician trainees, and various massage trainees.

In both specific examples, the application pressure beauty system according to the first embodiment can express and evaluate in real time the pressure applied to the face by fingers or hands, which has previously been difficult to visualize or evaluate, without installing sensors on the fingertips or hands.

In the above embodiment, an example was described in which the pressure on the face when applying cosmetics to the face with fingers or hands was measured and evaluated via the myoelectric potential of the arm. However, the application pressure evaluation system according to the first embodiment can also measure and evaluate the pressure on the face when applying cosmetics to the face using a puff or cotton, as shown in Figure 18. In this case, it is preferable to set the appropriate range of myoelectric potential described above that is suitable for the puff or cotton, taking into account the thickness of the puff or cotton and friction with the skin.

[Second embodiment]
<Schematic configuration of application pressure evaluation system>
An application pressure evaluation system 100 according to a second embodiment will be described with reference to Figures 19 and 20. Figure 19 is a schematic diagram of the application pressure evaluation system 100 according to the second embodiment. Figure 20 is a functional block diagram of the application pressure evaluation system 100 according to the second embodiment. The application pressure evaluation system 100 of the second embodiment differs from the application pressure evaluation system 10 of the first embodiment in that it evaluates the application pressure by using an accelerometer 4 (measurement device) to detect acceleration (measured value) when a user applies cosmetics to their face with their hands. The method of setting the appropriate range is the same as in the first embodiment.

The application pressure evaluation system 100 of this embodiment has an accelerometer 4 and an information processing device 5.

As shown in Figure 19, the accelerometer 4 is attached to the user's wrist and detects the application pressure by acceleration when the user applies cosmetics to their face with their hand. As shown in Figure 19, the accelerometer 4 is attached to the wrist, and the direction of movement is perpendicular to the contact surface between the palm and cheek. In this embodiment, the accelerometer 4 is attached to the wrist, but it may also be attached to the upper arm or forearm.

The accelerometer 4 is, for example, a three-axis acceleration sensor that detects acceleration in the x-axis, y-axis, and z-axis directions. Specific examples include smartphones, electromyography sensors, inertial measurement units, etc., which have built-in three-axis acceleration sensors.

The information processing device 5 is capable of communicating with the accelerometer 4, can acquire acceleration from the accelerometer 4, and evaluates and notifies the application pressure based on the acceleration. This information processing device 5 may be an information processing terminal for evaluation, such as a smartphone, tablet, mobile phone, or laptop, capable of outputting audio and/or images. Alternatively, it may be a dedicated information processing terminal for this application pressure evaluation system 100.

In the application pressure evaluation system 100, a speaker, projector, etc. may be connected to the information processing device 5, in which case the notification function may be performed by audio from the speaker or a projected image from the projector.

Communication between the information processing device 5 and the accelerometer 4 is achieved, for example, via Bluetooth (registered trademark), infrared communication, Wi-Fi (registered trademark), etc.

As shown in FIG. 20, the information processing device 5 has an acceleration acquisition unit 51, a frequency power spectrum calculation unit 52, an appropriate range storage unit 53, a comparison unit 54, an audio output unit 55, and a display unit 56. The audio output unit 55 and the display unit 56 together form the notification unit 58. The frequency power spectrum calculation unit 52, the appropriate range storage unit 53, and the comparison unit 54 together form the evaluation unit 57.

The acceleration acquisition unit 51 is an acquisition unit that acquires acceleration, and acquires the acceleration measured by the accelerometer 4 via communication. If a smartphone is used as the accelerometer 4, an application for recording acceleration may be used as the acceleration acquisition unit 51.

The frequency power spectrum calculation unit 52 acquires acceleration data obtained when applying cosmetics at a specific frequency, long enough to extract the target frequency components. It then uses a frequency filter to reduce the effects of gravitational acceleration and noise contained in the acquired acceleration waveform, and performs a fast Fourier transform (FFT) to obtain a frequency power spectrum. From the acquired frequency power spectrum, it then detects the power value of the target frequency. The highest power value on the x-axis, y-axis, or z-axis may be used. When the direction and period of motion are fixed, Newton's equation of motion (F = ma) dictates that the acceleration of an object is proportional to the force (Force [N]) acting on the object. When pressing a cheek with the palm of the hand (hand press), it is assumed that no external forces are acting on the hand or arm. Therefore, the force acting on the hand is likely to depend significantly on the user's muscle movement. Based on the above, we believe that by measuring the acceleration during hand pressing while fixing the direction and period of movement of the upper arm, forearm, or wrist, it is possible to approximately estimate the magnitude of the force generated by the muscle movement of the upper arm, forearm, or wrist, i.e., the application pressure.

The appropriate range memory unit 53 is a memory unit that stores in advance the appropriate range of power values for the frequency to be detected.

The comparison unit 54 compares whether the power value of the target detection frequency obtained is within the appropriate range.

The notification unit 58 notifies whether the power value calculated from the acquired acceleration is within or outside the appropriate range based on the comparison result from the comparison unit 54.

When notifying by voice, the voice output unit 55 notifies by voice whether the detected power value is within or outside the appropriate range. In the case of voice, the notification may be given only when the power value is outside the appropriate range, or only when it is within the appropriate range.

When notifying by display, the display unit 56, for example, a display, displays the power value of the frequency to be detected and its appropriate range value superimposed on each other. The display may be, for example, a liquid crystal display panel, an EL (Electro-luminescence) or an OLED (Organic Light Emitting Diode) display panel, etc.

In addition, notifications by the notification unit 58 may be a combination of visual and audio notifications.

The functions of the frequency power spectrum calculation unit 52, appropriate range memory unit 53, and comparison unit 54 in the information processing device 5 are incorporated into a program such as an app, and can be executed by launching the app.

In addition, although not shown in the figure, the information processing device 5 also includes electronic components, such as a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), input/output interface, and internal bus, which perform information processing related to basic operations.

(Application pressure evaluation flow)
Next, a method for evaluating application pressure in the application pressure evaluation system 100 will be described with reference to Fig. 21. Fig. 21 shows a flow for evaluating application pressure to the face when the application pressure evaluation system 100 of the second embodiment is used.

In S11, as preparation, the app on the information processing device 5 is launched and the accelerometer 4 is attached to the user's forearm or wrist. At this time, the accelerometer 4 measures acceleration and transmits it to the information processing device 5.

At S12, the user begins applying cosmetics to their face using their hands.

In S13, the accelerometer 4 measures the acceleration of the forearm or wrist and transmits the measured acceleration to the information processing device 5.

In S14, the frequency power spectrum calculation unit 52 of the information processing device 5 calculates a frequency power spectrum (power spectrum) from the acquired acceleration waveform, and detects the power value of the frequency to be detected from the frequency power spectrum (this is the detection step).

In S15, the comparison unit 54 of the information processing device 5 compares the power value of the frequency to be detected, obtained from the frequency power spectrum of the acceleration waveform, with the stored appropriate range (comparison step).

In S16, strength information is notified based on the comparison result of the power value of the frequency to be detected, obtained from the frequency power spectrum of the acceleration waveform, against the appropriate range (notification step).

Then, S12 to S16 are repeated until application of the cosmetics to the face is completed in S17.

Once the application of cosmetics to the face is completed in S17, the accelerometer 4 is removed from the forearm or wrist in S18, and the flow ends.

In this way, the accelerometer is attached to the user's forearm or wrist, and the hand is free during the evaluation, allowing the user to perform the usual application method and evaluation without having to worry about contact between the sensor and the face.

The appropriate range used for the comparison in S15 of Figure 21 to evaluate the strength of pressure when applying cosmetics to the face is set in advance through experiments with multiple subjects. Below, we will explain how to set the appropriate range for the application pressure evaluation system.

An accelerometer 4 is attached to a location selected from the upper arm, forearm, and wrist of each of multiple subjects. The subjects press their faces repeatedly for 30 seconds at a frequency of once per second using the same pressing method as in the first embodiment. A sound may be generated from a speaker at a frequency of once per second, instructing the subjects to perform the press in time with the sound stimulus. The pressing period is not limited to once per second and can be any period. However, if the period is changed, two conditions must be met: (1) it must be possible to assume that a sine wave of the target frequency is sufficiently included within the data section to be analyzed, and (2) the period must be a movement period that the subjects can perform comfortably. Furthermore, the pressing period can be any period, not limited to 30 seconds, only if the above two conditions are met. The accelerometer 4 measures acceleration during the pressing and transmits the acceleration to the information processing device 5. The acceleration data from the accelerometer 4 to the information processing device 5 may be transmitted in real time during the pressing or all at once after the pressing. The analysis information processing device 3, similar to that of the first embodiment, may be used to analyze the acceleration data when setting the appropriate range.

The above pressing action is performed with four different strengths: normal force, about half the normal force, about twice the normal force, and the force that feels most comfortable. Normal force refers to the amount of force normally used when hand-pressing skin care cosmetics. Half the normal force refers to about half (1/2) the normal force mentioned above. About twice the normal force refers to about twice the normal force mentioned above. The most comfortable force refers to the force that feels most comfortable.

A frequency power spectrum is calculated from the acceleration waveform obtained by measuring with four different strengths: normal force, approximately half normal force, approximately twice normal force, and the force felt most comfortable. The appropriate range is then set by detecting the power value of the target frequency from the obtained frequency power spectrum. For example, the lower limit of the appropriate range may be set by averaging the power values of the axis with the highest peak in the frequency power spectrum when pressing with approximately half the normal force across multiple subjects. Furthermore, the upper limit of the appropriate range may be set by averaging the power values of the axis with the highest peak in the frequency power spectrum when pressing with approximately twice the normal force across multiple subjects. The appropriate range may have upper and lower limits, or only an upper limit or only a lower limit may be set. The method for analyzing the peaks of the frequency power spectrum is not limited to the method described above, and any method can be used. The appropriate range may also be set based on the correlation between the power value of the target frequency obtained from the frequency power spectrum and the subject's emotional information evaluation score, cheek moisture content, cheek moisture evaporation rate, etc., as shown in the first embodiment.

The appropriate range set as described above is stored in the appropriate range memory unit 53.

In this way, an appropriate range for evaluating application pressure can be set based on the experimental results of multiple subjects. Specific calculations are explained below.

<Experimental Example 2>
As described above, the acceleration of multiple subjects was measured for 45 seconds when pressing their faces at four different intensities: normal force, half the normal force, twice the normal force, and the most comfortable force, at a frequency of once per second (1 Hz). An iPhone (registered trademark) was used to measure acceleration, and the iPhone (registered trademark) was attached to the outside of the subject's upper arm with the back of the iPhone (registered trademark) in contact. The acceleration data was acquired using an iPhone (registered trademark) and the SensorLog app (Mosenia et al., 2018). The acceleration waveforms obtained were the normal force (FIG. 22A), half the normal force (FIG. 22B), twice the normal force (FIG. 22C), and the most comfortable force (FIG. 22D). The sampling frequency was 100 Hz. 22A to 22D are data from one of several subjects. Of the 45-second measurement time, the first 15 seconds were used as a familiarization period to grasp the 1 Hz movement rhythm, and the subsequent 30 seconds were used for data analysis.

Next, a high-pass filter was applied to the acceleration waveforms obtained in Figures 22A to 22D to reduce the effects of gravitational acceleration and noise. A Butterworth-type second-order zero-phase filter with a cutoff frequency of 0.05 Hz was applied. A 4096-point FFT was performed on the signal after applying the high-pass filter. Specifically, a cosine tapered (cos 10 taper) window function was applied to 30 seconds (3000 points) of data, followed by zero padding and an FFT. The discrete Fourier transform was then scaled by the length of the input signal, and the squares of the amplitude spectrum values for all frequencies except 0 and the Nyquist frequency were calculated to obtain the frequency power spectrum. The values for each band within the range of 0.977 Hz to 1.123 Hz were summed. As a result of the above, we obtained the frequency power spectrum when pressing with the usual force (Figure 23A), the frequency power spectrum when pressing with about half the usual force (Figure 23B), the frequency power spectrum when pressing with about twice the usual force (Figure 23C), and the frequency power spectrum when pressing with the force that felt most comfortable (Figure 23D).

From the obtained frequency power spectrum, the power value of the axis with the highest peak among the x-axis, y-axis, and z-axis was used. The power value of the axis with the highest peak was 1.06 G ² (y-axis) when pressing with normal force, 0.41 G ^{2 (y-axis) when pressing with about half the normal force, 2.63 G 2} (y-axis) when pressing with about twice the normal force, and 0.42 G ² (y-axis) when pressing with the most comfortable force. The power value of the axis with the highest peak was also used for other subjects. The appropriate range can be set, for example, as a range of ⁵⁰ % difference between the normal force and the most comfortable force, centered on the "most comfortable force." That is, in this experimental example, the appropriate value was 0.10 G ² or more and 0.72 G ² or less, calculated as 0.42±0.5×|1.06-0.42|.

As a result, the application pressure evaluation method in the second embodiment also makes it possible to evaluate the pressure applied to the face by the fingertips or hands in real time without installing sensors on the fingertips or hands.

In the above example, we described the application pressure applied along with the application of cosmetics, but the system of the present invention may also be applied to pressure evaluation (for example, how to press acupressure points or how to massage) without applying cosmetics.

The above describes in detail a preferred embodiment of the present invention, but the present invention is not limited to the specific embodiment described above, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

This international application claims priority to Japanese Patent Application No. 2020-084782, filed on May 13, 2020, the entire contents of which are hereby incorporated by reference into this international application.

1, 1' Electromyograph 2, 5 Information processing device 3 Analytical information processing device 4 Accelerometer 10, 10A, 10B, 10C, 100 Application pressure evaluation system 20 Analysis system 21 Myoelectric potential acquisition unit 22 RMS calculation unit (calculation unit)
23: Resting RMS value temporary storage unit 24: RMS change rate calculation unit (calculation unit)
25, 53 Appropriate range memory unit (memory unit)
26, 54 Comparison unit 27, 55 Audio output unit 28, 56 Display unit 57 Evaluation unit 29, 58 Notification unit 311 Myoelectric potential acquisition unit 312 RMS calculation unit (calculation unit)
313: Resting RMS value temporary storage unit 314: RMS change rate calculation unit 315: RMS change rate storage unit 321: Subject information acquisition unit 322: Correlation analysis unit 323: Appropriate range setting unit 324: Appropriate range accumulation unit 325: Transmission unit U: Individual user (user)
B. Beauty professional (beauty advisor)
C Customer T Beauty instructor BS Beauty student S Smartphone P PC

Claims (23)

a detection step of detecting, by a change in a measurement value, an application pressure when the user applies the cosmetic to the face with the hand of the user using a measurement device attached to the upper arm, forearm, or wrist of the user;
a comparison step of comparing whether a value calculated from the detected measurement value is within an appropriate range;
a notification step of notifying the user whether the value obtained from the measurement value is within or outside the appropriate range ,
The appropriate range is set based on a correlation between a value obtained from a measurement value measured using the measuring device when applying a cosmetic to the face by hand and one or more selected from emotional information, which is facial sensation, and measurement information of facial skin .
Application pressure evaluation method. The emotional information is one or more of comfort and preference, and the measurement information is one or more of skin moisture content and skin moisture evaporation rate.
The coating pressure evaluation method according to claim 1 . the measuring device is an electromyograph attached to the forearm of the user,
The measured value is a myoelectric potential.
The coating pressure evaluation method according to claim 1 or 2 . In the detecting step, the manner in which the user applies pressure to the face when applying the cosmetic with her/his hands and holding the area for a predetermined time is detected based on a change in the myoelectric potential of the forearm.
The coating pressure evaluation method according to claim 3 . In the detecting step, the manner in which the user applies force to the face when the user applies the cosmetic with her/his hands and moves multiple times in a certain direction while applying pressure to the face is detected based on a change in the myoelectric potential of the forearm.
The coating pressure evaluation method according to claim 3 . a measuring device attached to the upper arm, forearm, or wrist of a user, which detects application pressure by changes in measurement value when the user applies cosmetic material to the face with their hand;
an information processing device capable of acquiring the measurement value from the measurement device,
The information processing device includes:
an acquisition unit that acquires the measurement value of the measurement device;
a storage unit that stores the appropriate range;
a comparison unit that compares the value obtained from the acquired measurement value to determine whether it is within the appropriate range;
a notification unit that notifies whether the value obtained from the measurement value is within or outside the appropriate range ,
The appropriate range is set based on a correlation between a value obtained from a measurement value measured using the measuring device when applying a cosmetic to the face by hand and one or more selected from emotional information, which is facial sensation, and measurement information of facial skin .
Application pressure evaluation system. The emotional information is one or more of comfort and preference, and the measurement information is one or more of skin moisture content and skin moisture evaporation rate.
The coating pressure evaluation system according to claim 6 . the measuring device is an electromyograph attached to the forearm of the user,
The measured value is a myoelectric potential.
The coating pressure evaluation system according to claim 6 or 7 . the information processing device includes a calculation unit that, after acquiring the myoelectric potential, calculates a rate of change of a root mean square (RMS) of the amplitude of the myoelectric potential;
the comparison unit compares whether or not the RMS change rate of the myoelectric potential, which is a value calculated from the myoelectric potential, is within the appropriate range defined by the RMS change rate.
The coating pressure evaluation system according to claim 8 . the notification unit is a display,
The rate of change of the RMS of the myoelectric potential and the value of the appropriate range are displayed in an overlapping manner on the display.
The coating pressure evaluation system according to claim 9 . the notification unit is an audio output unit,
the audio output unit notifies by audio whether the detected myoelectric potential is within or outside the appropriate range.
The coating pressure evaluation system according to claim 8 . further comprising an appropriate range setting unit that sets the appropriate range;
The appropriate range setting unit sets an appropriate range having upper and lower limits corresponding to the strength of application pressure to the face with a high evaluation value of comfort based on a correlation established between (i) the strength of application pressure to the face detected by changes in the myoelectric potential of the forearm when each of the multiple subjects applies cosmetic material to their face with their hands at multiple application pressure strengths by attaching electromyographs to the forearms of the multiple subjects, and (ii) the evaluation value of comfort for each of the multiple application pressures obtained from each of the multiple subjects.
The coating pressure evaluation system according to claim 6 . further comprising an appropriate range setting unit that sets the appropriate range;
The appropriate range setting unit sets an appropriate range having upper and lower limits corresponding to the strength of application pressure to the face according to the preferred evaluation value, based on a correlation established between (i) the strength of application pressure to the face detected by changes in the myoelectric potential of the forearm when each of the multiple subjects applies the cosmetic to the face with their hands at multiple application pressure strengths by attaching electromyographs to the forearms of the multiple subjects, and (ii) the preferred evaluation value for each of the multiple application pressures obtained from each of the multiple subjects.
The coating pressure evaluation system according to claim 6 . further comprising an appropriate range setting unit that sets the appropriate range;
The appropriate range setting unit sets an appropriate range having upper and lower limits so that the application pressure is the same as that used by subjects with high cheek moisture, based on a correlation established between (i) the strength of application pressure to the face that is normally applied by the subjects, detected by changes in the myoelectric potential of the forearm when the subjects attach electromyographs to the forearms and apply the cosmetic to their faces with their hands at the strength that each of the subjects normally applies the cosmetic to, and (ii) the cheek moisture content obtained from each of the subjects.
The coating pressure evaluation system according to claim 6 . further comprising an appropriate range setting unit that sets the appropriate range;
The appropriate range setting unit
Electromyographs were attached to the forearms of multiple subjects, and the application pressure when each subject applied cosmetics to their face by hand at the strength they normally use was detected by measuring changes in the myoelectric potential of the forearm.
Obtaining the amount of water evaporation from the facial skin of each of the subjects after application;
(i) the strength of application pressure to the face that is usually applied, detected by changes in the myoelectric potential of the forearm when electromyographs are attached to the forearms of multiple subjects and the multiple subjects each apply a cosmetic to their face with a strength that is usually applied by each of the multiple subjects, and (ii) the amount of water evaporation from the facial skin after application, obtained from each of the multiple subjects, based on a correlation between the strength of application pressure to the face that is usually applied, detected by changes in the myoelectric potential of the forearm, and (ii) the amount of water evaporation from the facial skin after application, obtained from each of the multiple subjects,
An appropriate range having an upper limit is set so as to exclude a range in which the amount of water evaporation is high.
The coating pressure evaluation system according to claim 6 . A method for setting the appropriate range in the coating pressure evaluation system according to any one of claims 6 to 11, comprising :
a detection value acquisition step of attaching electromyographs to the forearms of a plurality of subjects, and detecting the application pressures of the plurality of subjects when they apply the cosmetic to their faces with their hands at a plurality of different application pressure intensities, based on changes in the myoelectric potential of the forearms;
A step of acquiring an evaluation value of comfort for each of a plurality of application pressures from each of a plurality of subjects;
A step of correlating the strength of application pressure on the face with the evaluation value of comfort;
and a range setting step of setting an appropriate range having upper and lower limits in accordance with the strength of the application pressure on the face that had a high evaluation value of comfort.
A method for setting an appropriate range in a dispensing pressure evaluation system. A method for setting the appropriate range in the coating pressure evaluation system according to any one of claims 6 to 11, comprising :
a detection value acquisition step of attaching electromyographs to the forearms of a plurality of subjects, and detecting the application pressures of the plurality of subjects applying the cosmetic to their faces with their hands at a plurality of application pressure intensities by detecting changes in the myoelectric potential of the forearms;
obtaining preference evaluation values for each of a plurality of application pressures from each of a plurality of subjects;
A step of correlating the strength of application pressure on the face with the preference evaluation value;
and a range setting step of setting an appropriate range having upper and lower limits in accordance with the strength of the application pressure on the face according to the preferred evaluation value.
A method for setting an appropriate range in a dispensing pressure evaluation system. A method for setting the appropriate range in the coating pressure evaluation system according to any one of claims 6 to 11, comprising :
a detection value acquisition step of attaching electromyographs to the forearms of a plurality of subjects and detecting application pressures based on changes in the myoelectric potential of the forearms when the plurality of subjects apply cosmetics to their faces with their hands at the strength that they normally use;
acquiring the moisture content of the skin of each of the subjects;
A process of correlating the strength of application pressure to the face when applied daily with the moisture content of the cheeks;
and a range setting step of setting an appropriate range having upper and lower limits so that the application pressure is the same as that applied to a subject with a high cheek moisture content.
A method for setting an appropriate range in a dispensing pressure evaluation system. A method for setting the appropriate range in the coating pressure evaluation system according to any one of claims 6 to 11, comprising :
a detection value acquisition step of attaching electromyographs to the forearms of a plurality of subjects and detecting application pressures based on changes in the myoelectric potential of the forearms when the plurality of subjects apply cosmetics to their faces with their hands at the strength that they normally use;
Obtaining the amount of water evaporation from the facial skin of each of the subjects after application;
A step of correlating the strength of application pressure to the face when applied daily with the amount of water evaporation;
A range setting step of setting an appropriate range having an upper limit so as to exclude a range in which the amount of water evaporation is large.
A method for setting an appropriate range in a dispensing pressure evaluation system. the measuring device is an accelerometer;
The measurement value is acceleration.
The coating pressure evaluation method according to claim 1 or 2 . In the detecting step, the manner in which the user applies pressure to the face when applying the cosmetic with their hands and holding the area for a predetermined period of time is detected based on the acceleration.
The method for evaluating application pressure according to claim 20 . In the detecting step, the manner in which the force is applied to the face when the user applies the cosmetic by hand and moves multiple times in a certain direction while applying pressure to the face is detected based on the acceleration.
The method for evaluating application pressure according to claim 20 . the measuring device is an accelerometer;
The measurement value is acceleration.
The coating pressure evaluation system according to claim 6 or 7 .