Self-adaptive micro-current beautifying method and beautifying instrument based on electrophysiological index feedback

Abstract

The invention discloses a self-adaptive micro-current beauty method and beauty instrument based on electrophysiological index feedback, and relates to the technical field of photoelectric beauty, the method comprises the following steps: obtaining a surface electromyogram signal of a user face, extracting characteristic data of the surface electromyogram signal, and determining current intensity and current frequency of an NMES based on the characteristic data; acquiring a first feedback electric signal and a second feedback electric signal to determine the impedance value of the skin cuticle and the impedance value of the active skin layer, and determining the current intensity of the micro-current and the working time proportion of the NMES and the micro-current according to the impedance values of the skin cuticle and the active skin layer; therefore, a user face electrical stimulation signal is determined. According to the method and the device, parameters of the NMES and the micro-current can be adaptively adjusted, so that different somatosensory and beautifying effects are generated according to different skin states, and a good beautifying effect can be achieved while the somatosensory of a user is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric beauty, in particular to a self-adaptive microcurrent beauty method based on electrophysiological index feedback and a beauty instrument. BACKGROUND

[0002] In recent years, the beauty market has seen the rise of photoelectric beauty projects. Photoelectric beauty projects refer to medical beauty methods that use ultrasonic, radio frequency, photonic and other medical beauty devices to achieve skin tightening, lifting, wrinkle removal, spot removal, whitening and other ideal beauty effects. Photoelectric beauty projects have the advantages of strong targeting, short recovery period, minimal or no invasion, and are a relatively mild and safe beauty technology that is deeply loved by consumers.

[0003] In the photoelectric beauty technology for home use, EMS is a muscle training method using low-frequency current technology, which involves the application of electric current through the skin to trigger repetitive muscle contractions. Low-frequency current technology for facial beauty can be divided into neuromuscular electrical stimulation (NMES) and microcurrent according to the strength of the current, and the two have different current strengths, different effects and different user sensations. EMS technology that can produce a comfortable sensation and instant lifting effect is NMES; EMS technology that can produce ATP and promote cell metabolism is microcurrent. Through the EMS waveform test results of handheld home beauty instruments, it is found that traditional EMS generally only uses NMES technology, and the initial design of the product is to provide a comfortable sensation and instant lifting effect. It is currently not possible to ensure user comfort while also achieving good beauty results. SUMMARY

[0004] The purpose of the present application is to provide a self-adaptive microcurrent beauty method based on electrophysiological index feedback and a beauty instrument, which can ensure user comfort while also achieving good beauty results.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] In a first aspect, the present application provides a self-adaptive microcurrent beauty method based on electrophysiological index feedback, comprising:

[0007] Obtaining a surface electromyogram of a user's face and performing feature extraction on the surface electromyogram to obtain feature data of the surface electromyogram; the feature data includes a straight line slope and a goodness of fit.

[0008] acquire a first feedback electrical signal, and determine an impedance value of a stratum corneum according to the first feedback electrical signal; the first feedback electrical signal is a signal measured by a feedback resistor after an electrode applies a low-frequency electrical signal to a user's face.

[0009] acquire a second feedback electrical signal, and determine an impedance value of a living skin layer according to the second feedback electrical signal and the impedance value of the stratum corneum; the second feedback electrical signal is a signal measured by a feedback resistor after an electrode applies a high-frequency electrical signal to a user's face.

[0010] determine whether a linear slope of the surface electromyography signal is greater than a linear slope threshold value to obtain a first determination result; when the first determination result is yes, determine a current intensity of NMES according to an NMES high-current intensity model; when the first determination result is no, determine the current intensity of NMES according to an NMES low-current intensity model; the NMES refers to nerve-muscle electrical stimulation.

[0011] determine whether a goodness of fit of the surface electromyography signal is less than a goodness of fit threshold value to obtain a second determination result; when the second determination result is yes, determine a current frequency of NMES according to an NMES high-current frequency model; when the second determination result is no, determine the current frequency of NMES according to an NMES low-current frequency model.

[0012] determine whether the impedance value of the stratum corneum is greater than a stratum corneum impedance threshold value to obtain a third determination result; when the third determination result is yes, set a current intensity of a micro-current to a fixed low-current intensity value, and set a working time ratio of NMES and the micro-current to 1:1; when the third determination result is no, determine the current intensity of the micro-current according to a micro-current high-current intensity model, and determine whether the impedance value of the living skin layer is less than a living skin layer impedance threshold value to obtain a fourth determination result.

[0013] when the fourth determination result is yes, set the working time ratio of NMES and the micro-current to 1:2; when the fourth determination result is no, set the working time ratio of NMES and the micro-current to 1:4.

[0014] determine a user's facial electrical stimulation signal according to the current intensity of the NMES, the current frequency of the NMES, the current intensity of the micro-current, and the working time ratio of NMES and the micro-current.

[0015] In a second aspect, the application provides an adaptive micro-current beauty instrument based on electrophysiological index feedback, comprising an electrode, a feedback resistor, and a master control chip.

[0016] Both the electrode and the feedback resistor are connected to the main control chip; the feedback resistor is used to connect to the user's facial skin through the electrode.

[0017] The electrodes are used to collect surface electromyographic signals from the user's face, and to apply low-frequency electrical signals, high-frequency signals, and electrical stimulation signals to the user's face.

[0018] The feedback resistor is used to output a first feedback electrical signal when the electrode applies a low-frequency electrical signal to the user's face, and to output a second feedback electrical signal when the electrode applies a high-frequency electrical signal to the user's face.

[0019] The main control chip is used for:

[0020] Feature extraction is performed on the surface electromyography signal to obtain the feature data of the surface electromyography signal.

[0021] The impedance value of the stratum corneum of the skin is determined based on the first feedback electrical signal.

[0022] The impedance value of the active skin layer is determined based on the second feedback electrical signal and the impedance value of the stratum corneum.

[0023] Determine whether the slope of the linear electromyography signal is greater than a slope threshold to obtain a first determination result; when the first determination result is yes, determine the current intensity of NMES according to the NMES high current intensity model; when the first determination result is no, determine the current intensity of NMES according to the NMES low current intensity model.

[0024] Determine whether the goodness of fit of the surface electromyography signal is less than the goodness of fit threshold to obtain a second determination result; when the second determination result is yes, determine the current frequency of NMES according to the high current frequency model of NMES; when the second determination result is no, determine the current frequency of NMES according to the low current frequency model of NMES.

[0025] A third judgment result is obtained by determining whether the impedance value of the stratum corneum is greater than the impedance threshold of the stratum corneum. When the third judgment result is yes, the current intensity of the microcurrent is set to a fixed low current intensity value, and the working time ratio of NMES and microcurrent is set to 1:1. When the third judgment result is no, the current intensity of the microcurrent is determined according to the high current intensity model of microcurrent, and the impedance value of the active skin layer is determined whether it is less than the impedance threshold of the active skin layer, thus obtaining a fourth judgment result.

[0026] When the fourth judgment result is yes, the working time ratio of NMES and microcurrent is set to 1:2; when the fourth judgment result is no, the working time ratio of NMES and microcurrent is set to 1:4.

[0027] The electrodes are controlled to electrically stimulate the user's face according to the current intensity of the NMES, the current frequency of the NMES, the current intensity of the microcurrent, and the working time ratio of the NMES and the microcurrent.

[0028] According to the specific embodiments provided in this application, this application has the following technical effects:

[0029] This application provides an adaptive microcurrent beauty method and device based on electrophysiological index feedback. It acquires surface electromyography (EMG) signals from the user's face and extracts feature data from these signals: the slope of a straight line and the goodness of fit. When the slope of the straight line is greater than a threshold, the current intensity of the NMES is determined according to a high-current-intensity model; when the slope of the straight line is not greater than the threshold, the current intensity of the NMES is determined according to a low-current-intensity model. Furthermore, when the goodness of fit is less than a threshold, the current frequency of the NMES is determined according to a high-current-frequency model; when the goodness of fit is not less than a threshold, the current frequency of the NMES is determined according to a low-current-frequency model. A first feedback electrical signal and a second feedback electrical signal are acquired to determine the impedance value of the stratum corneum and the impedance value of the active skin layer. When the impedance value of the stratum corneum is greater than the impedance of the stratum corneum... At the threshold, the current intensity of the microcurrent is set to a fixed low current intensity value, and the working time ratio of NMES to microcurrent is set to 1:1. When the impedance value of the stratum corneum is not greater than the stratum corneum impedance threshold, the current intensity of the microcurrent is determined according to the high current intensity model of the microcurrent. Furthermore, when the impedance value of the stratum corneum is not greater than the stratum corneum impedance threshold, and the impedance value of the active skin layer is less than the active skin layer impedance threshold, the working time ratio of NMES to microcurrent is set to 1:2. When the impedance value of the stratum corneum is not greater than the stratum corneum impedance threshold, and the impedance value of the active skin layer is not less than the active skin layer impedance threshold, the working time ratio of NMES to microcurrent is set to 1:4. Finally, the facial electrical stimulation signal of the user is determined based on the current intensity and frequency of NMES, the current intensity of the microcurrent, and the working time ratio of NMES to microcurrent. Through the above scheme, this application realizes the combination of NMES (neuromuscular electrical stimulation) and microcurrent technology for facial beauty treatment. It can adaptively adjust the parameters of neuromuscular electrical stimulation and microcurrent according to the electrophysiological indicators of the user's facial skin and subcutaneous muscles, thereby producing different sensations and beauty effects for different skin conditions, ensuring user sensation while achieving good beauty results. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram illustrating the difference between NMES and microcurrent provided in an embodiment of this application;

[0032] Figure 2 A schematic flowchart of an adaptive microcurrent cosmetic method based on electrophysiological index feedback provided in an embodiment of this application;

[0033] Figure 3 A schematic flowchart of another adaptive microcurrent cosmetic method based on electrophysiological index feedback provided in an embodiment of this application;

[0034] Figure 4 A schematic diagram of the process for adaptively adjusting NMES parameters based on surface electromyography signals, provided in an embodiment of this application;

[0035] Figure 5 A schematic diagram of a process for adaptively adjusting microcurrent parameters based on skin impedance, provided in an embodiment of this application;

[0036] Figure 6 This is a schematic diagram showing the alternating operation of NMES and microcurrent according to preset parameters provided in an embodiment of this application;

[0037] Figure 7 A schematic diagram of the functional modules of an adaptive microcurrent beauty device based on electrophysiological index feedback provided in an embodiment of this application;

[0038] Figure 8 This is a schematic diagram of the workflow of an adaptive microcurrent beauty device based on electrophysiological index feedback provided in an embodiment of this application. Detailed Implementation

[0039] Currently, low-frequency current technology used for facial aesthetics can be divided into two types based on the current intensity: neuromuscular electrical stimulation (NMES) and microcurrent. Figure 1 As shown, the main difference between the two is:

[0040] 1. Different current intensities: The current intensity of NMES is 2-80mA, while the current intensity of microcurrent is within 500uA. The current intensity of NMES is several to tens of times that of microcurrent.

[0041] 2. Different Effects: NMES stimulates muscle contraction, causing muscle length to decrease and thickness to increase while maintaining muscle volume, thus lifting facial contours. Microcurrents have two effects: first, they stimulate ATP production, increasing collagen fiber support; second, they mimic endogenous electric fields to manipulate transmembrane potential, regulating cell growth, differentiation, and function, and increasing cell membrane permeability. This technology stimulates facial muscles, with energy waves almost identical to the body's natural ion flow, and can increase ATP concentration by up to 400%, while simultaneously stimulating protein synthesis and promoting amino acid transport, further increasing cell membrane permeability. ATP is the primary energy source for cells, promoting the production of key structural proteins, such as collagen and elastin in skin structure, providing the skin with the necessary elasticity to restore its original shape.

[0042] 3. Different user sensations: NMES has a high current intensity, and depending on the waveform, it can make users feel different sensations such as tingling or numbness. Microcurrents have no obvious sensation.

[0043] The purpose of this application is to combine NMES (neuromuscular electrical stimulation) and microcurrent technologies for facial cosmetic purposes. It can adaptively adjust the parameters of neuromuscular electrical stimulation and microcurrent according to the electrophysiological indicators of the user's facial skin and subcutaneous muscles, thereby producing different sensations and cosmetic effects for different skin conditions, ensuring both user comfort and good cosmetic results.

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0045] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Example 1

[0047] like Figures 2-5 As shown, an adaptive microcurrent cosmetic method based on electrophysiological index feedback is provided, including steps 101 to 108. Wherein:

[0048] Step 101: Acquire surface electromyography (EMG) signals from the user's face, and extract features from the EMG signals to obtain feature data of the EMG signals; the feature data includes the slope of the line and the goodness of fit.

[0049] Step 102: Obtain the first feedback electrical signal and determine the impedance value of the stratum corneum of the skin based on the first feedback electrical signal; the first feedback electrical signal is the signal obtained by applying a low-frequency electrical signal to the user's face through an electrode and then measuring it using a feedback resistor.

[0050] Step 103: Obtain the second feedback electrical signal, and determine the impedance value of the active skin layer based on the second feedback electrical signal and the impedance value of the stratum corneum; the second feedback electrical signal is the signal obtained by applying a high-frequency electrical signal to the user's face through an electrode and then measuring it using a feedback resistor.

[0051] Step 104: Determine whether the slope of the surface electromyography signal is greater than the slope threshold to obtain a first determination result; when the first determination result is yes, determine the current intensity of NMES according to the NMES high current intensity model; when the first determination result is no, determine the current intensity of NMES according to the NMES low current intensity model; NMES refers to neuromuscular electrical stimulation.

[0052] The current intensity of NMES determined based on the high current intensity model of NMES is written as I. h·NMES The current intensity of NMES determined according to the NMES low current intensity model is written as I. l·NMES .

[0053] Step 105: Determine whether the goodness of fit of the surface electromyography signal is less than the goodness of fit threshold to obtain a second determination result; when the second determination result is yes, determine the current frequency of NMES according to the NMES high current frequency model; when the second determination result is no, determine the current frequency of NMES according to the NMES low current frequency model.

[0054] The current frequency of the NMES, determined based on the high-current-frequency model of the NMES, is written as F. h·NMES The current frequency of NMES, determined based on the NMES low-current frequency model, is written as F. l·NMES .

[0055] Step 106: Determine whether the impedance value of the stratum corneum is greater than the impedance threshold of the stratum corneum to obtain a third determination result; when the third determination result is yes, set the current intensity of the microcurrent to a fixed low current intensity value and set the working time ratio of NMES and microcurrent to 1:1; when the third determination result is no, determine the current intensity of the microcurrent according to the high current intensity model of microcurrent, and determine whether the impedance value of the active skin layer is less than the impedance threshold of the active skin layer to obtain a fourth determination result.

[0056] Step 107: When the fourth judgment result is yes, the working time ratio of NMES and microcurrent is set to 1:2; when the fourth judgment result is no, the working time ratio of NMES and microcurrent is set to 1:4.

[0057] Step 108: Determine the facial electrical stimulation signal based on the current intensity of the NMES, the current frequency of the NMES, the current intensity of the microcurrent, and the ratio of the working time of the NMES and the microcurrent. Figure 6 As shown.

[0058] As an optional implementation, the mathematical expression of the NMES high current intensity model is as follows:

[0059] I NMES =80-10×(K) s -K th ) 2 K s >K th ;

[0060] Among them, I NMES This indicates the current intensity of NMES, measured in milliamperes (mA); K s The slope of the straight line representing the surface electromyography signal; K th This represents the slope threshold of the straight line, with a default setting of 0.2. If K... s >K th This indicates that the muscles are fatigued, and a high-intensity electrical current can be used for massage.

[0061] The mathematical expression for the NMES low current intensity model is as follows:

[0062] I NMES =2+0.5×(K) s -K th ) 2 K s ≤K th ;

[0063] I NMES The unit is also milliampere (mA). If K... s ≤K th This indicates that the muscles are not easily fatigued, and low-intensity electrical stimulation can be used for massage.

[0064] Combining the two formulas above, we get:

[0065] As an optional implementation, the mathematical expression of the NMES high-current frequency model is as follows:

[0066] F NMES =200-20×(D) s -Dth ) 2 D s >D th ;

[0067] Among them, F NMES D represents the current frequency of NMES, measured in Hertz (Hz). s D represents the goodness of fit of the surface electromyography signal; th This represents the goodness-of-fit threshold, which is set to 0.8 by default. If D... s <D th This indicates that the muscle condition is unstable and can be relieved using tingling electrical stimulation. The current frequency of the NMES should be set to a high current frequency.

[0068] The mathematical expression for the NMES low-current frequency model is as follows:

[0069] F NMES =50+10×(D) s -D th ) 2 D s ≤D th .

[0070] If D s ≥D th This indicates that the muscle condition is stable, and mild treatment can be performed using weaker somatosensory electrical stimulation. The current frequency of the NMES is set to a low current frequency.

[0071] Combining the two formulas above, we get:

[0072] As an optional implementation, the mathematical expression of the microcurrent high current intensity model is as follows:

[0073] I MICRO =400+50×(R) y -T y ), R x ≤T x ;

[0074] Among them, I MICRO R represents the current intensity of a microcurrent, measured in microamperes; x Indicates the impedance value of the stratum corneum of the skin; T x This represents the threshold value of the skin's stratum corneum impedance, which is the impedance threshold of the healthy skin stratum corneum under a 100Hz excitation signal; R y Indicates the impedance value of the active skin layer; T y This represents the impedance threshold of the active skin layer, which is the impedance threshold of a healthy active skin layer under a 100,000 Hz excitation signal.

[0075] The fixed low current intensity value is 300μA.

[0076] Therefore, we can conclude that:

[0077] If the impedance value R of the stratum corneum of the skin x >T x This indicates that the stratum corneum is functioning normally and the user has healthy skin. In this case, the working time ratio of NMES and microcurrent is set to 1:1. If the impedance value R of the stratum corneum is... x <T x And the impedance value R of the active skin layer y <T y This indicates that the stratum corneum function is impaired, but the moisture content of the active skin layer is normal, and the user is mildly sensitive. In this case, the working time ratio of NMES and microcurrent should be set to 1:2; if the impedance value R of the stratum corneum... x <T x And the impedance value R of the active skin layer y >T y This indicates that the stratum corneum function is impaired and the active skin layer is dehydrated, and the user is moderately sensitive. In this case, the working time ratio of NMES and microcurrent is set to 1:4.

[0078] Among them, T x It is the impedance threshold of the healthy skin stratum corneum under a 100Hz excitation signal, T y It is the impedance threshold of a healthy, active skin layer under a 100,000 Hz excitation signal, both of which were measured in advance by experiments.

[0079] Figure 5 The current intensities of the two microcurrents, 350μA and 450μA, are specific values ​​calculated based on the microcurrent high current intensity model in a certain experimental case.

[0080] As an optional implementation method, such as Figure 4 As shown, step 101 specifically includes:

[0081] Step 101.1: Acquire surface electromyography (EMG) signals from the electrodes when the user makes a smiling expression; the electrodes are used to closely adhere to the skin surface of the user's jawline, and the electrodes are in detection mode at this time.

[0082] When a user makes a smiling expression, they control their facial muscles to pull the corners of their mouth towards behind their ears. It is necessary to record the surface electromyography (EMG) signals h(t) generated during the entire process of facial muscle contraction.

[0083] Step 101.2: Perform bandpass filtering on the surface electromyography signal to obtain the filtered surface electromyography signal.

[0084] Specifically, the surface electromyography signal h(t) is bandpass filtered from 50Hz to 200Hz to eliminate inherent system noise, power frequency interference, etc.

[0085] Step 101.3: Divide the filtered surface electromyography signal into several signal segments of equal duration, and calculate the mean and variance of each signal segment.

[0086] Specifically, a sliding window is used to sequentially extract signal segments of 0.2 s duration from the filtered surface electromyography signal h′(t), and the mean s(n) and variance p(n) of all sampling points within each signal segment are calculated as follows:

[0087]

[0088] Where fs is the sampling frequency of the surface electromyography signal; n is the sequence number of the signal segment, N≥n≥1, and N is the total number of signal segments.

[0089] Step 101.4: Perform a linear fit on the mean s(n) of several signal segments to obtain the slope K of the straight line. s ;

[0090] Step 101.5: Perform linear fitting on the variance p(n) of several signal segments to obtain the goodness of fit D. s .

[0091] As an optional implementation method, such as Figure 5 As shown, in step 102, determining the impedance value of the stratum corneum based on the first feedback electrical signal specifically includes:

[0092] Step 102.1: Determine the impedance value of the stratum corneum based on the first feedback electrical signal, the resistance value of the feedback resistor, and the low-frequency electrical signal; wherein, the determination process of the first feedback electrical signal is as follows: when the user's facial muscles are relaxed, apply a 500mV, 100Hz low-frequency electrical signal U1 to the user's facial skin using electrodes; and use the feedback resistor (resistance value R) to determine the impedance value of the stratum corneum. re The first feedback electrical signal U1′ is measured; the feedback resistor is connected to the user's face through the electrode (also called the EMS electrode).

[0093] Specifically, the impedance value R of the stratum corneum of the skin is calculated using the following formula. x :

[0094]

[0095] As an optional implementation method, such as Figure 5As shown, in step 103, determining the impedance value of the active skin layer based on the second feedback electrical signal and the impedance value of the stratum corneum specifically includes:

[0096] Step 103.1: Determine the parallel impedance value of the stratum corneum and the active skin layer based on the second feedback electrical signal, the resistance value of the feedback resistor, and the high-frequency electrical signal; wherein, the process of determining the second feedback electrical signal is as follows: when the user's facial muscles are relaxed, a 100mV, 100000Hz high-frequency electrical signal U2 is applied to the user's facial skin using electrodes; using the feedback resistor (resistance value R... re The second feedback electrical signal U2′ was obtained by measurement.

[0097] Step 103.2: Determine the parallel impedance value of the stratum corneum and the active skin layer based on the second feedback electrical signal, the feedback resistor and the high-frequency electrical signal.

[0098] Specifically, the parallel impedance value R of the stratum corneum and the active skin layer is calculated using the following formula. 总 :

[0099]

[0100] Step 103.3: Determine the impedance value of the active skin layer based on the parallel impedance value of the stratum corneum and the active skin layer and the impedance value of the stratum corneum.

[0101] Specifically, the impedance value R of the active skin layer is calculated using the following formula. y :

[0102]

[0103] Example 2

[0104] Based on the same inventive concept, this application also provides an adaptive microcurrent beauty device based on electrophysiological index feedback. The solution provided by this beauty device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the adaptive microcurrent beauty device based on electrophysiological index feedback provided below can be found in the limitations of the adaptive microcurrent beauty method based on electrophysiological index feedback described above, and will not be repeated here.

[0105] In one exemplary embodiment, such as Figure 7 As shown, an adaptive microcurrent beauty device based on electrophysiological index feedback is provided, including: electrode M1, feedback resistor M2 and main control chip M3.

[0106] Both the electrode M1 and the feedback resistor M2 are connected to the main control chip; the feedback resistor M2 is used to connect to the user's facial skin through the electrode M1.

[0107] The electrode M1 is used to collect surface electromyographic signals of the user's face, and to apply low-frequency electrical signals, high-frequency signals and electrical stimulation signals to the user's face.

[0108] The feedback resistor M2 is used to output a first feedback electrical signal when the electrode M1 applies a low-frequency electrical signal to the user's face, and to output a second feedback electrical signal when the electrode applies a high-frequency electrical signal to the user's face.

[0109] For example, the main control chip M3 applies a low-frequency electrical signal U1 to the user's facial skin through the electrode M1, and then the main control chip M3 measures the first feedback electrical signal U1′ through the feedback resistor M2; the main control chip M3 applies a high-frequency electrical signal U2 to the user's facial skin through the electrode M1, and then the main control chip M3 measures the second feedback electrical signal U2′ through the feedback resistor M2.

[0110] like Figure 8 As shown, the main control chip M3 is used for:

[0111] 1) Extract features from the surface electromyography signal to obtain feature data of the surface electromyography signal.

[0112] 2) Determine the impedance value of the stratum corneum of the skin based on the first feedback electrical signal.

[0113] 3) Determine the impedance value of the active skin layer based on the second feedback electrical signal and the impedance value of the stratum corneum.

[0114] 4) Determine whether the slope of the linear electromyography signal is greater than the slope threshold to obtain a first determination result; when the first determination result is yes, determine the current intensity of NMES according to the NMES high current intensity model; when the first determination result is no, determine the current intensity of NMES according to the NMES low current intensity model.

[0115] 5) Determine whether the goodness of fit of the surface electromyography signal is less than the goodness of fit threshold to obtain a second judgment result; when the second judgment result is yes, determine the current frequency of NMES according to the high current frequency model of NMES; when the second judgment result is no, determine the current frequency of NMES according to the low current frequency model of NMES.

[0116] 6) Determine whether the impedance value of the stratum corneum is greater than the impedance threshold of the stratum corneum to obtain a third determination result; when the third determination result is yes, set the current intensity of the microcurrent to a fixed low current intensity value and set the working time ratio of NMES and microcurrent to 1:1; when the third determination result is no, determine the current intensity of the microcurrent according to the high current intensity model of microcurrent, and determine whether the impedance value of the active skin layer is less than the impedance threshold of the active skin layer to obtain a fourth determination result.

[0117] 7) When the fourth judgment result is yes, the working time ratio of NMES and microcurrent is set to 1:2; when the fourth judgment result is no, the working time ratio of NMES and microcurrent is set to 1:4.

[0118] 8) Control the electrode M1 to electrically stimulate the user's face according to the current intensity of the NMES, the current frequency of the NMES, the current intensity of the microcurrent, and the working time ratio of the NMES and the microcurrent. At this time, the electrode is in the output state.

[0119] This application has the following beneficial effects:

[0120] 1) An adaptive microcurrent technology based on feedback from skin and subcutaneous muscle electrophysiological indicators is proposed. This technology alternates between two low-frequency currents, neuromuscular electrical stimulation (NMES) and microcurrent, for beauty purposes. It has both the comfortable sensation of NMES and the beauty effect of microcurrent promoting ATP production.

[0121] 2) Analyze the user's muscle state based on the surface electromyography (EMG) signals of the user's facial skin, and adaptively adjust the NMES stimulation parameters accordingly to achieve personalized NMES beauty effects.

[0122] 3) Based on the electrical impedance analysis of the user's facial skin stratum corneum and active skin layer, the user's skin sensitivity status is analyzed, and the microcurrent stimulation parameters are adaptively adjusted accordingly. Different microcurrent stimulation intensities and working time ratios are given to healthy skin, mildly sensitive skin, and moderately sensitive skin, thus realizing a low-frequency current beauty solution with low irritation customized for sensitive skin.

[0123] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0124] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An adaptive microcurrent cosmetic method based on electrophysiological index feedback, characterized in that, The adaptive microcurrent cosmetic method based on electrophysiological index feedback includes: Acquire surface electromyography (EMG) signals from the user's face, and extract features from the EMG signals to obtain feature data of the EMG signals; the feature data includes the slope of the line and the goodness of fit; A first feedback electrical signal is acquired, and the impedance value of the stratum corneum of the skin is determined based on the first feedback electrical signal; the first feedback electrical signal is a signal obtained by applying a low-frequency electrical signal to the user's face through electrodes and then measuring it using a feedback resistor. A second feedback electrical signal is acquired, and the impedance value of the active skin layer is determined based on the second feedback electrical signal and the impedance value of the stratum corneum. The second feedback electrical signal is a signal obtained by applying a high-frequency electrical signal to the user's face through an electrode and then measuring it using a feedback resistor. The first determination result is obtained by determining whether the slope of the linear electromyography signal is greater than the slope threshold. When the first determination result is yes, the current intensity of NMES is determined according to the high current intensity model of NMES. When the first determination result is no, the current intensity of NMES is determined according to the low current intensity model of NMES. NMES refers to neuromuscular electrical stimulation. Determine whether the goodness of fit of the surface electromyography signal is less than the goodness of fit threshold to obtain a second determination result; when the second determination result is yes, determine the current frequency of NMES according to the NMES high current frequency model; when the second determination result is no, determine the current frequency of NMES according to the NMES low current frequency model. The system determines whether the impedance value of the stratum corneum is greater than the impedance threshold of the stratum corneum, thus obtaining a third determination result. When the third determination result is yes, the current intensity of the microcurrent is set to a fixed low current intensity value, and the working time ratio of NMES and microcurrent is set to 1:

1. When the third determination result is no, the current intensity of the microcurrent is determined according to the high current intensity model of microcurrent, and the system determines whether the impedance value of the active skin layer is less than the impedance threshold of the active skin layer, thus obtaining a fourth determination result. When the fourth judgment result is yes, the working time ratio of NMES and microcurrent is set to 1:2; when the fourth judgment result is no, the working time ratio of NMES and microcurrent is set to 1:

4. The facial electrical stimulation signal is determined based on the current intensity of the NMES, the current frequency of the NMES, the current intensity of the microcurrent, and the ratio of the working time of the NMES and the microcurrent.

2. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 1, characterized in that, The mathematical expression for the NMES high current intensity model is as follows: I NMES =80-10×(K s -K th ) 2 ,K s >K th ; Among them, I NMES K represents the current intensity of NMES. s The slope of the straight line representing the surface electromyography signal; K th This represents the threshold for the slope of a straight line.

3. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 2, characterized in that, The mathematical expression for the NMES low current intensity model is as follows: I NMES =2+0.5×(K s -K th ) 2 ,K s ≤K th 。 4. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 1, characterized in that, The mathematical expression for the NMES high-current frequency model is as follows: F NMES =200-20×(D s -D th ) 2 ,D s >D th ; Among them, F NMES Indicates the current frequency of NMES; D s D represents the goodness of fit of the surface electromyography signal; th This represents the goodness-of-fit threshold.

5. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 4, characterized in that, The mathematical expression for the NMES low-current frequency model is as follows: F NMES =50+10×(D s -D th ) 2 ,D s ≤D th 。 6. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 1, characterized in that, The mathematical expression for the microcurrent high current intensity model is as follows: I MICRO =400+50×(R y -T y ),R x ≤T x ; Among them, I MICRO R represents the current intensity of a microcurrent. x Indicates the impedance value of the stratum corneum of the skin; T x This represents the threshold value of the skin's stratum corneum impedance, which is the impedance threshold of the healthy skin stratum corneum under a 100Hz excitation signal; R y Indicates the impedance value of the active skin layer; T y This represents the impedance threshold of the active skin layer, which is the impedance threshold of a healthy active skin layer under a 100,000 Hz excitation signal.

7. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 1, characterized in that, Acquire surface electromyography (EMG) signals from the user's face, and extract features from the EMG signals to obtain feature data of the EMG signals, specifically including: The surface electromyography (EMG) signals are acquired by electrodes when the user makes a smiling expression; the electrodes are used to closely adhere to the skin surface of the user's jawline. The surface electromyography (EMG) signal is subjected to bandpass filtering to obtain the filtered surface EMG signal. The filtered surface electromyography signal is divided into several signal segments of equal duration, and the mean and variance of each signal segment are calculated. The slope of the line is obtained by fitting a straight line to the mean of several signal segments; The goodness of fit is obtained by performing a linear fit on the variance of several signal segments.

8. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 7, characterized in that, Determining the impedance value of the stratum corneum based on the first feedback electrical signal specifically includes: The impedance value of the stratum corneum is determined based on the first feedback electrical signal, the resistance value of the feedback resistor, and the low-frequency electrical signal. The determination process of the first feedback electrical signal is as follows: when the user's facial muscles are relaxed, a low-frequency electrical signal of 500mV and 100Hz is applied to the user's facial skin using electrodes; the first feedback electrical signal is obtained by measuring the feedback resistor; the feedback resistor is connected to the user's face through the electrodes.

9. The adaptive microcurrent cosmetic method based on electrophysiological index feedback according to claim 8, characterized in that, The impedance value of the active skin layer is determined based on the second feedback electrical signal and the impedance value of the stratum corneum, specifically including: Based on the second feedback electrical signal, the resistance value of the feedback resistor, and the high-frequency electrical signal, the parallel impedance value of the stratum corneum and the active skin layer is determined; wherein, the process of determining the second feedback electrical signal is as follows: when the user's facial muscles are relaxed, a high-frequency electrical signal of 100mV and 100000Hz is applied to the user's facial skin using electrodes; the second feedback electrical signal is obtained by measuring using the feedback resistor; The impedance value of the active skin layer is determined based on the parallel impedance value of the stratum corneum and the active skin layer and the impedance value of the stratum corneum.

10. An adaptive microcurrent beauty device based on electrophysiological index feedback, characterized in that, The adaptive microcurrent beauty device based on electrophysiological index feedback includes: electrodes, feedback resistors, and a main control chip; Both the electrode and the feedback resistor are connected to the main control chip; the feedback resistor is used to connect to the user's facial skin through the electrode. The electrodes are used to collect surface electromyography signals from the user's face, and to apply low-frequency electrical signals, high-frequency signals, and electrical stimulation signals to the user's face. The feedback resistor is used to output a first feedback electrical signal when the electrode applies a low-frequency electrical signal to the user's face, and to output a second feedback electrical signal when the electrode applies a high-frequency electrical signal to the user's face. The main control chip is used for: Feature extraction is performed on the surface electromyography signal to obtain the feature data of the surface electromyography signal; The impedance value of the stratum corneum of the skin is determined based on the first feedback electrical signal; The impedance value of the active skin layer is determined based on the second feedback electrical signal and the impedance value of the stratum corneum. Determine whether the slope of the linear electromyography signal is greater than a slope threshold to obtain a first determination result; when the first determination result is yes, determine the current intensity of NMES according to the NMES high current intensity model; when the first determination result is no, determine the current intensity of NMES according to the NMES low current intensity model. Determine whether the goodness of fit of the surface electromyography signal is less than the goodness of fit threshold to obtain a second determination result; when the second determination result is yes, determine the current frequency of NMES according to the NMES high current frequency model; when the second determination result is no, determine the current frequency of NMES according to the NMES low current frequency model. The system determines whether the impedance value of the stratum corneum is greater than the impedance threshold of the stratum corneum, thus obtaining a third determination result. When the third determination result is yes, the current intensity of the microcurrent is set to a fixed low current intensity value, and the working time ratio of NMES and microcurrent is set to 1:

1. When the third determination result is no, the current intensity of the microcurrent is determined according to the high current intensity model of microcurrent, and the system determines whether the impedance value of the active skin layer is less than the impedance threshold of the active skin layer, thus obtaining a fourth determination result. When the fourth judgment result is yes, the working time ratio of NMES and microcurrent is set to 1:2; when the fourth judgment result is no, the working time ratio of NMES and microcurrent is set to 1:

4. The electrodes are controlled to electrically stimulate the user's face according to the current intensity of the NMES, the current frequency of the NMES, the current intensity of the microcurrent, and the working time ratio of the NMES and the microcurrent.

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