Method of detecting skin, PPG sensor and electronic device

Abstract

The application provides a method for detecting skin, a PPG sensor and an electronic device. The method for detecting skin comprises: emitting a first light signal by the PPG sensor to excite a skin tissue to emit a fluorescent signal; receiving the fluorescent signal by the PPG sensor and converting to obtain a first current signal; and generating skin information according to the first current signal. The skin tissue can be detected by the PPG sensor, so that a user can conveniently and quickly master the relevant information of the skin tissue.

Description

Technical Field

[0001] This application relates to the field of mobile electronic device technology, and more particularly to a method for detecting skin, a PPG sensor, and an electronic device. Background Technology

[0002] Wearable electronic devices have developed rapidly in recent years. As a type of portable device, they can be worn directly on the user's body for easy carrying. Wearable electronic devices are not merely hardware devices; they can also achieve powerful functions through software support, data interaction, and cloud interaction, bringing significant changes to our lives and perceptions.

[0003] In related technologies, wearable electronic devices can monitor users' health indicators by setting up a photoplethysmo graphy (PPG) sensor and measuring heart rate based on PPG technology. However, health-related indicators are not limited to heart rate indicators; they also include skin tissue indicators.

[0004] In daily activities, people inevitably come into contact with ultraviolet rays from the outside world. Long-term exposure of human skin to ultraviolet rays can cause abnormalities in skin tissue. However, existing wearable electronic devices cannot detect skin tissue and cannot meet user needs. Summary of the Invention

[0005] This application provides a method for detecting skin, a PPG sensor, and an electronic device that can detect skin tissue.

[0006] In a first aspect, embodiments of this application provide a method for detecting skin, comprising:

[0007] A PPG sensor is used to emit a first light signal to excite the skin tissue to emit a fluorescent signal.

[0008] The fluorescence signal is received using a PPG sensor and converted into a first current signal;

[0009] Skin information is generated based on the first current signal.

[0010] Secondly, embodiments of this application also provide a PPG sensor, which includes:

[0011] A first light-emitting component, used to emit a first light signal that excites skin tissue to emit fluorescence; and

[0012] A photoelectric sensor is used to receive the fluorescence signal and convert it into a first current signal, which is used to generate skin information.

[0013] Thirdly, embodiments of this application also provide an electronic device, which includes a housing and a PPG sensor as described above, wherein the housing is provided with a detection window for signal transmission, and the PPG sensor is disposed within the housing.

[0014] Fourthly, embodiments of this application also provide an electronic device, which includes a processing module and a PPG sensor, the PPG sensor comprising:

[0015] A first light-emitting component, used to emit a first light signal that excites skin tissue to emit fluorescence; and

[0016] A photoelectric sensor is used to receive the fluorescence signal and convert it into a first current signal; the photoelectric sensor is electrically connected to the processing module, and the processing module acquires the first current signal through the photoelectric sensor and generates skin information based on the first current signal.

[0017] In the embodiments provided in this application, a PPG sensor is used to emit a first light signal to excite the skin tissue to emit a fluorescence signal. For example, a PPG sensor is used to emit blue light to excite the protoporphyrin IX in the skin tissue to emit a fluorescence signal. The PPG sensor is then used to receive the fluorescence signal and convert it into a first current signal. Skin information can be generated based on the first current signal to detect the skin tissue, allowing users to conveniently and quickly obtain relevant information about the skin tissue. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of 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.

[0019] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0020] Figure 1 This is a schematic diagram of the front structure of an electronic device provided in an embodiment of this application.

[0021] Figure 2 This is a schematic diagram of the first structure of the back of an electronic device provided in an embodiment of this application.

[0022] Figure 3 This is a schematic diagram of the normalized absorption spectrum and fluorescence emission spectrum of protoporphyrin IX.

[0023] Figure 4 The excitation and emission path diagram of the fluorescence signal provided in the embodiments of this application is shown.

[0024] Figure 5 This is a schematic diagram of a second structure on the back of an electronic device provided in an embodiment of this application.

[0025] Figure 6 This is a schematic flowchart of a skin detection method provided in an embodiment of this application. Detailed Implementation

[0026] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0027] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the front structure of the electronic device provided in the embodiments of this application. Figure 2 This is a first structural schematic diagram of the back of an electronic device provided in an embodiment of this application. The electronic device 100 can be a wearable electronic device, which can be directly worn by the user for convenient carrying. Examples of wearable devices include smartwatches, smart bracelets, smart glasses, and others. It is understood that this application does not limit the specific type of electronic device 100. This application uses a smartwatch as an example to further illustrate the technical solution of the electronic device 100.

[0028] The electronic device 100 may include a housing 10, a main screen 20, and a strap 40. The housing 10 serves to house and protect electronic components, such as circuit boards (PCBs) and power modules. The housing 10 can be made of non-metallic materials such as plastic, rubber, silicone, wood, ceramic, or glass, or it can be made of metallic materials such as stainless steel, aluminum alloy, or magnesium alloy. The housing 10 can also be a metal injection molded part, where the metal material ensures the structural rigidity of the housing 10, and the inner surface of the metal body is injection molded to form protrusions, grooves, threaded holes, and other structures for assembly and positioning.

[0029] The housing 10 has a detection window for light transmission, allowing the transmission of light signals emitted and reflected by electronic components such as the PPG sensor 30 built into the housing 10. This enables the detection of vital signs such as heart rate, blood oxygen saturation, and skin information. It can be understood that when the PPG sensor 30 detects heart rate and blood oxygen saturation, it can record changes in blood vessel volume during the cardiac cycle based on differences in reflected light intensity, thereby obtaining vital signs such as heart rate and blood oxygen saturation.

[0030] The housing 10 can be roughly rectangular, with the four corners rounded to give the electronic device 100 a better appearance. In one embodiment, the housing 10 can also be circular. The sides of the housing 10 can have a mating structure for mounting the watch strap 40. The watch strap 40 can reliably connect to the housing 10 through this structure, allowing the electronic device 100 to be reliably worn on the user's hand. In one embodiment, the watch strap 40 can also be easily detached from the housing 10, allowing the user to easily replace it. For example, the user can purchase various styles of watch straps 40 and change them according to the usage scenario to improve ease of use. For instance, a more formal watch strap 40 can be used in formal occasions, while a more casual style can be used in leisure and entertainment settings.

[0031] The main screen 20 is mounted on the housing 10 and is used to display functional information such as time. The main screen 20 can be a screen with touch screen control function, which can not only display functional information such as time, but also perform touch screen operation to realize the functions required by the user, such as setting the time or selecting other functions.

[0032] It should be noted that people inevitably come into contact with ultraviolet (UV) radiation during daily activities. Prolonged exposure to UV radiation can cause abnormalities in skin tissue. For example, UV radiation from sunlight has been shown to cause DNA damage and immunosuppression. Long-term exposure to UV radiation often manifests as sun damage, typically presenting as red, light red, or reddish-brown, round or irregular erythema or thin patches on exposed areas. It can even lead to actinic keratosis and non-melanoma skin cancer (NMSC). However, existing wearable electronic devices cannot detect skin tissue abnormalities and therefore cannot meet user needs.

[0033] Based on this, the photoplethysmo graphy (PPG) sensor provided in this application measure relevant information of skin tissue using PPG technology and quantitative fluorescence measurement methods, enabling the electronic device 100 to have the corresponding function of detecting skin tissue. The quantitative fluorescence measurement method refers to combining fluorescence and physiological characteristics. Since normal and abnormal tissues emit different fluorescence spectra under certain conditions, comparing the two fluorescence spectra allows for a preliminary judgment on whether the skin tissue is abnormal.

[0034] It is understandable that the content of ferrous chelate enzyme in tumors (abnormal tissues) differs from that in normal tissue cells. Therefore, the ability of tumor cells to metabolize porphyrins also differs from that of normal tissue cells. Ferrous chelate enzyme is an enzyme that catalyzes the combination of ferrous ions with protoporphyrin IX (PpIX) to form heme. Due to the accumulation of protoporphyrin IX in tumor cells, the activity of ferrous chelate enzyme is reduced, thus reducing the combination of protoporphyrin IX with ferrous ions to form heme, further increasing the intracellular concentration of protoporphyrin IX. Therefore, the concentration of protoporphyrin IX in tumor cells differs from that in normal tissue cells.

[0035] Among them, protoporphyrin IX can be excited by light signals of a certain wavelength to produce fluorescence signals. The intensity of the fluorescence signals produced varies depending on the concentration of protoporphyrin IX. Therefore, the concentration of protoporphyrin IX is a key feature for molecular fluorescence diagnosis of tumors.

[0036] The PPG sensor 30 provided in this embodiment includes a first light-emitting component 31 and a photoelectric sensor 32. The first light-emitting component 31 emits a first light signal to excite the skin tissue to emit a fluorescent signal. For example, the first light-emitting component 31 can emit blue light, which excites protoporphyrin IX in the skin tissue to generate a fluorescent signal. The photoelectric sensor 32 receives this fluorescent signal and converts it into a first current signal, which is used to generate skin information. In this way, skin tissue can be detected, allowing the user to obtain relevant information about the skin tissue.

[0037] The photoelectric sensor 32 can operate in a zero-bias state, meaning it can be a photovoltaic-mode photodiode (PD). The photodiode (PD) can receive fluorescence signals emitted by skin tissue and convert the received fluorescence signals into a first current signal.

[0038] Please see Figure 3 , Figure 3This is a schematic diagram of the normalized absorption spectrum and fluorescence spectrum of protoporphyrin IX, where the left curve is the absorption spectrum of protoporphyrin IX and the right curve is the fluorescence spectrum of protoporphyrin IX. Figure 3 The curve on the right, representing the fluorescence spectrum of protoporphyrin IX, shows that fluorescence emission peaks around a wavelength of 635 nm. Therefore, to ensure better reception of the fluorescence signal by the photoelectric sensor 32, the preferred first optical signal is one that excites protoporphyrin IX in skin tissue to produce a fluorescence signal with a wavelength of 635 nm. Research by the inventors has shown that a first optical signal with a wavelength between 395 nm and 420 nm can excite protoporphyrin IX in skin tissue to produce a fluorescence signal with a wavelength of 635 nm. Therefore, an optical signal with a wavelength between 395 nm and 420 nm can be selected as the first optical signal. It is understood that the range of 395 nm to 420 nm includes both 395 nm and 420 nm.

[0039] Among them, from Figure 3 As can be seen from the curve on the left, i.e. the absorption spectrum of protoporphyrin IX, the absorption of protoporphyrin IX reaches its peak at a wavelength of around 409 nm. That is, under the illumination of light at this wavelength, the fluorescence signal intensity excited by protoporphyrin IX is the highest. Therefore, the first light signal with a wavelength of 409 nm can be preferred to excite protoporphyrin IX in the skin tissue to emit a fluorescence signal, so that the photoelectric sensor 32 can better receive the fluorescence signal.

[0040] For example, the first light-emitting component 31 may include a blue light-emitting diode (LED) capable of emitting blue light with a wavelength of 409 nanometers. The blue light emitted by the LED excites protoporphyrin IX in the skin tissue to emit a fluorescence signal with a wavelength of 635 nanometers. The photoelectric sensor 32 receives the fluorescence signal and converts it into a first current signal, which is then used to generate skin information. The skin information can be current information or other information converted from the current information, such as image information or data information. This application does not impose specific limitations on the specific display format of the skin information. It is also understood that the skin information can be transmitted to the main screen 20 for display, or it can be sent to a mobile phone or other device for display.

[0041] It is understandable that the concentration of protoporphyrin IX in abnormal skin tissue is higher than that in normal tissue. Therefore, when blue light irradiates normal skin tissue, the intensity of the fluorescence signal at a wavelength of 635nm is lower, while when blue light irradiates abnormal skin tissue, the intensity of the fluorescence signal at a wavelength of 635nm is higher. As a result, the first current signal converted by the photoelectric sensor 32 based on the fluorescence signal also differs. Therefore, a preliminary diagnosis of the skin tissue can be made by judging the current threshold generated by the photoelectric sensor 32 after receiving the fluorescence signal.

[0042] For example, the PPG sensor 30 may also include a processing module (not shown), which is electrically connected to the photoelectric sensor 32. The processing module acquires a first current signal through the photoelectric sensor 32 and generates skin information based on the first current signal. For instance, the processing module can store a current threshold value for normal skin tissue as a preset current threshold. When the first light signal irradiates the skin tissue to be tested, it excites the skin tissue to emit a fluorescence signal. This fluorescence signal is received by the photoelectric sensor 32, which converts it into a first current signal. The processing module acquires this first current signal through the photoelectric sensor 32 and compares it with the preset current threshold value, generating skin information based on the comparison result. If the threshold value of the first current signal is greater than the preset current threshold value, skin information indicating abnormal skin tissue is generated. If the threshold value of the first current signal is less than or equal to the preset current threshold value, skin information indicating normal skin tissue is generated. In this way, relevant information about the skin tissue can be obtained.

[0043] It is understandable that the processing module can be part of the PPG sensor 30 or part of an external component with corresponding processing functions.

[0044] It should be noted that the PPG sensor 30 may include a green LED 331, a red LED 332, and an infrared LED 333. Based on the different intensities of the reflected light when the green LED 331, red LED 332, and infrared LED 333 illuminate the blood, the changes in blood vessel volume during the cardiac cycle can be recorded, thereby obtaining vital signs signals such as heart rate and blood oxygen saturation. For example, the green LED 331 in the PPG sensor 30 emits green light that passes through the tissues and arteries / veins in the skin and is absorbed and reflected back to the photodiode. Understandably, the absorption of light by tissues such as muscles, bones, veins, and other connecting tissues is essentially constant (provided there is no significant movement at the measurement site). However, blood is different; due to the flow of blood in arteries, its light absorption naturally varies. When the light reflected to the photodiode 32 is converted into an electrical signal, because the absorption of light by arteries changes while the absorption by other tissues remains essentially constant, the resulting signal can be divided into a direct current signal and an alternating current signal. By extracting the communication signals, the characteristics of blood flow can be reflected, and thus the heart rate can be detected based on these communication signals.

[0045] The inventors discovered that protoporphyrin IX also absorbs a small amount of light in the green light band and is excited to emit a fluorescent signal. Therefore, a green LED 331 with a wavelength between 520 nm and 540 nm can be used instead of a blue LED, such as a green LED 331 that emits light with a wavelength of 535 nm, meaning that a blue LED is not required. It is understood that the range of 520 nm to 540 nm includes both 520 nm and 540 nm.

[0046] To enhance the fluorescence signal and detection performance, aminolevulinic acid (ALA) solvent can be used to generate a slightly higher concentration of protoporphyrin IX in skin tissue, thereby facilitating the reception of the fluorescence signal generated by the photoelectric sensor 32. ALA is an effective photosensitizer; when absorbed by epidermal or appendage cells, it is converted into protoporphyrin IX. For example, a certain amount of ALA can be applied to the skin to be tested and a period of time, such as 1 hour, can be waited for absorption by the skin, resulting in a slightly higher concentration of protoporphyrin IX, which facilitates the reception of the fluorescence signal generated by the photoelectric sensor 32.

[0047] It is understandable that when applying ALA, the preset current threshold stored in the processing module is obtained after applying the same concentration of ALA to normal skin. In other words, it is necessary to ensure that the only variable is skin tissue, and other conditions need to remain the same.

[0048] In some embodiments, to enable detection of different locations in skin tissue, i.e., to increase the detection range, a single first light-emitting component 31 and multiple photoelectric sensors 32 can be configured. The multiple photoelectric sensors 32 are positioned differently, and each photoelectric sensor 32 at a different location receives fluorescence signals emitted from different locations in the skin tissue. It is understood that the light emitted by the first light-emitting component 31, when it shines on the skin, excites protoporphyrin IX in the skin tissue to emit fluorescence signals. Skin information in the corresponding area can only be detected when the fluorescence signal is received by the photoelectric sensor 32. For example, when two photoelectric sensors 32 are configured, skin information at two different locations in the skin tissue can be detected; when three photoelectric sensors 32 are configured, skin information at three different locations in the skin tissue can be detected; and when four photoelectric sensors 32 are configured, skin information at four different locations in the skin tissue can be detected.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0050] For example, please refer to Figure 4 , Figure 4 This is a diagram illustrating the excitation and emission path of a fluorescence signal provided in an embodiment of this application. When there are two photoelectric sensors 32, such as a first photoelectric sensor 321 and a second photoelectric sensor 322, the first light signal emitted by the first light-emitting component 31, when irradiated onto the skin, excites protoporphyrin IX in the skin tissue to emit a fluorescence signal, such as... Figure 4 Region A is the area covered by the first light signal. The first photoelectric sensor 321 can receive the fluorescence signal emitted by the first position B, and at this time, the skin information of the first position B can be detected. The second photoelectric sensor 322 can receive the fluorescence signal emitted by the second position C, and at this time, the skin information of the second position C can be detected.

[0051] It is understandable that the specific location and number of photoelectric sensors 32 can be set according to actual needs, such as... Figure 2 As shown, four photoelectric sensors 32 can be set, and one first light-emitting component 31 can be set. The four photoelectric sensors 32 are arranged at intervals and around the first light-emitting component 31.

[0052] Alternatively, the first light-emitting component 31 can be configured as multiple components, with multiple photoelectric sensors 32 spaced apart and arranged around the light-emitting module 33. In the surrounding direction, a first light-emitting component 31 is positioned between two adjacent photoelectric sensors 32. For example, ... Figure 5 As shown, Figure 5 This is a second structural diagram of the back of the electronic device provided in an embodiment of this application. Four first light-emitting components 31 and four photoelectric sensors 32 can be configured. The four photoelectric sensors 32 are spaced apart and arranged around the light-emitting module 33. In the surrounding direction, a first light-emitting component 31 is arranged between two adjacent photoelectric sensors 32.

[0053] The light-emitting module 33 can be one, any two, or three of the following: green LED 331, infrared LED 333, and red LED 332.

[0054] It should be noted that the photosensitive wavelength of the photoelectric sensor 32 used in the electronic device 100 is between 400 nanometers and 1100 nanometers, while the wavelengths of green light, red light and infrared light are 535 nanometers, 660 nanometers and 940 nanometers, respectively. In order to further suppress the interference of other non-interest wavelengths, filters can be used to limit the photosensitive wavelength of the photoelectric sensor 32. For example, a filter can be placed on the optical signal receiving path of the photoelectric sensor 32 to suppress interference from other non-interest wavelengths. For instance, the filter can be a 488 nm long-pass filter, which can reduce the receiving efficiency below 488 nm to eliminate interference from signals with wavelengths below 488 nm. In this way, interference from the first optical signal used to excite the skin tissue to emit fluorescence, such as blue light, can be prevented. At the same time, the receiving efficiency of the long-pass filter for signals with wavelengths above 488 nm is approximately unaffected. Therefore, it does not affect the measurement of heart rate, blood oxygen, etc., of the green LED 331, red LED 332, and infrared LED 333 in the PPG sensor 30, nor does it affect the fluorescence signal with a wavelength of 635 nm during skin detection.

[0055] This application also provides a method for detecting skin. Please refer to [link to relevant documentation]. Figure 6 , Figure 6 This is a schematic flowchart illustrating a skin detection method provided in an embodiment of this application. The skin detection method includes:

[0056] 510: A first light signal is emitted using a PPG sensor 30 to excite the skin tissue to emit a fluorescent signal. The first light signal can be blue light, which is used to excite protoporphyrin IX in the skin tissue to emit a fluorescent signal by irradiating the skin tissue with blue light.

[0057] 520: The PPG sensor 30 receives the fluorescence signal and converts it into a first current signal. For example, the photoelectric sensor 32 can receive the fluorescence signal and convert it into a first current signal.

[0058] 530: Generate skin information based on the first current signal.

[0059] In section 530, generating skin information based on the first current signal may include:

[0060] The first current signal is compared with a preset current threshold to obtain a comparison result. It is understood that the first current signal can be compared with the preset current threshold by a processing module. For example, the processing module can store the current threshold of normal skin as the preset current threshold. When the processing module receives the first current signal, it can compare the first current signal with the preset current threshold to obtain a comparison result.

[0061] Skin information is generated based on the comparison results.

[0062] Generating skin information based on the comparison results may include:

[0063] If the threshold of the first current signal is greater than the preset current threshold, skin information indicating abnormal skin tissue is generated.

[0064] If the threshold of the first current signal is less than or equal to the preset current threshold, then skin information indicating that the skin tissue is normal skin tissue is generated.

[0065] To enhance the fluorescence signal and detection performance, before step 510, the method may further include step 540: applying a preset amount of ALA to the skin to be tested and waiting for a preset time. During this time, the ALA applied to the skin can be absorbed by epidermal or appendage cells, and after absorption, a slightly higher concentration of protoporphyrin IX is generated, which facilitates the reception of the fluorescence signal generated by the photoelectric sensor 32.

[0066] In the embodiments provided in this application, a health function for detecting skin lesions can be added to the existing health functions of the PPG sensor 30. Specifically, the PPG sensor 30 emits a first light signal, such as blue light, to excite protoporphyrin IX in the skin tissue to emit a fluorescent signal. The PPG sensor 30 receives this fluorescent signal and converts it into a first current signal, thereby generating skin information based on this first current signal. This allows for the detection of skin tissue, enabling users to access relevant information about their skin. The method is low-cost, highly integrated, and maintains an aesthetically pleasing appearance. Users can actively place the electronic device 100 equipped with the PPG sensor 30 on the desired skin location for measurement, providing a better user experience. Furthermore, it allows for regular monitoring of the health status of human skin tissue, enabling early screening for skin lesions and informing users of further diagnosis and medical treatment, thus better managing their skin health.

[0067] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0068] The above provides a detailed description of the skin detection method, PPG sensor, and electronic device provided in the embodiments of this application. Specific examples have been used 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 method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A PPG sensor, characterized in that, include: The first light-emitting component is used to emit a first light signal that excites the skin tissue to emit a fluorescent signal; as well as A photoelectric sensor, wherein the photoelectric sensor is used to receive the fluorescence signal and convert the fluorescence signal into a first current signal; The processing module is electrically connected to the photoelectric sensor and is used to generate skin information based on the comparison result of the first current signal and a preset current threshold.

2. The PPG sensor according to claim 1, characterized in that, The wavelength of the first optical signal is between 395 nanometers and 420 nanometers.

3. The PPG sensor according to claim 1, characterized in that, The wavelength of the first optical signal is between 520 nanometers and 540 nanometers.

4. The PPG sensor according to any one of claims 1 to 3, characterized in that, There are multiple photoelectric sensors, and the multiple photoelectric sensors are set in different positions. The photoelectric sensors at different positions are used to receive fluorescence signals emitted from different locations in the skin tissue.

5. An electronic device, characterized in that, The device includes a housing and a PPG sensor as described in any one of claims 1 to 4, wherein the housing is provided with a detection window for signal transmission, and the PPG sensor is disposed within the housing.

6. An electronic device, characterized in that, It includes a processing module and a PPG sensor, the PPG sensor comprising: A first light-emitting component, used to emit a first light signal that excites skin tissue to emit fluorescence; and A photoelectric sensor, wherein the photoelectric sensor is used to receive the fluorescence signal and convert the fluorescence signal into a first current signal; The photoelectric sensor is electrically connected to the processing module. The processing module acquires the first current signal through the photoelectric sensor and generates skin information based on the comparison result of the first current signal and a preset current threshold.

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