Sensitive skin classification care phototherapy device and control method

Abstract

The application discloses a sensitive skin type nursing light therapy device and a control method, and relates to LED light biological regulation technology. The device comprises a shell, a lamp panel, 320 LED lamp beads and a control unit. The LED lamp beads are only composed of 160 yellow light LEDs with a wavelength of 570 nm and 160 red light LEDs with a wavelength of 630 nm, and do not contain infrared light LEDs. The control unit receives sensitive skin type information and calls corresponding schemes. For a blood vessel nerve high-sensitivity type, pure yellow light is first output for 10 minutes, and then composite light with a yellow-to-red energy density ratio of 7:3 is output for 5 minutes. For a barrier damage type, 3:7 composite light is output for 15 minutes. For a mixed type, 5:5 composite light is output for 15 minutes. The yellow-to-red energy density ratio can be calibrated before leaving the factory and verified through spectral measurement. The application binds sensitive skin type information with a yellow-to-red dual-waveband scheme without infrared light, and realizes differentiated light output control through independent PWM channels.

Description

Technical Field

[0001] This invention relates to the field of phototherapy and skin care equipment technology, specifically to a phototherapy device and control method for sensitive skin type-based care. The invention also relates to the application of photobiomodulation (PBM) technology in differentiated care for sensitive skin, and the use of non-disease diagnostic skin care type information based on the lactate stinging test (LAST) and capsaicin test (CAT) in light output control. Background Technology

[0002] Sensitive skin is a hyperreactive state of the skin that occurs under physiological or pathological conditions. It is mainly characterized by discomfort such as stinging, burning, itching, tightness, and redness in the facial skin when stimulated by physical, chemical, or environmental factors. The formation mechanism of sensitive skin is complex, involving multiple pathways including impaired skin barrier function, increased neurovascular reactivity (especially overactivation of the capsaicin receptor TRPV1), innate immune inflammation, and oxidative stress. The main related mechanisms are not entirely the same in different individuals—some individuals primarily exhibit neurovascular hyperreactivity, some primarily exhibit barrier function deficiency, and some exhibit both.

[0003] Currently, the main methods for caring for sensitive skin include skincare products, medication, and aesthetic treatments. Skincare products primarily act on the surface of the stratum corneum and are unlikely to directly regulate the neurovascular responses and inflammatory cascades in the dermis. Preferably, 7:3, 3:7, and 5:5 are target yellow-red energy density ratios; the calibrated energy density ratio is the ratio of the energy density of the yellow band to the energy density of the red band corresponding to the factory calibration parameters set according to the target yellow-red energy density ratio; in the prototype, the calibrated energy density ratio can be confirmed by band measurement using a spectroradiometer at a distance of 10 cm from the light-emitting surface of the LED bead, and the calibrated energy density ratio is within the preset allowable deviation range of the target yellow-red energy density ratio, wherein the preset allowable deviation range is that the relative deviation of the ratio of the calibrated energy density ratio to the target yellow-red energy density ratio does not exceed ±10%; the PWM duty cycle is the factory calibration parameter used to achieve the calibrated energy density ratio.

[0004] Preferably, the first phototherapy scheme has an irradiance of approximately 8 mW / cm² and an energy density of approximately 4.8 J / cm² in the pure yellow light stage at a distance of 10 cm, an irradiance of approximately 9.5 mW / cm² and an energy density of approximately 2.85 J / cm² in the composite light (Ⅰ) stage, and a total energy density of approximately 7.65 J / cm² in a single session; the second phototherapy scheme has an irradiance of approximately 11 mW / cm² at a distance of 10 cm and a total energy density of approximately 9.9 J / cm² in a single session, of which the red light energy is approximately 6.93 J / cm²; the third phototherapy scheme has an irradiance of approximately 10.5 mW / cm² at a distance of 10 cm and a total energy density of approximately 9.45 J / cm² in a single session; the above irradiance and energy density are example values, and the allowable deviation range is ±10%.

[0005] Preferably, the housing includes a front panel, a rear cover, a lamp board, a condenser lens, a lens plate, and a fixing plate. Each LED bead is provided with a corresponding condenser lens, and the condenser lens is fixed on the lens plate. The lamp board and the lens plate are fixed relative to each other by the fixing plate. The front panel has 320 light-transmitting holes, which correspond one-to-one with the 320 LED beads.

[0006] Preferably, the device further includes an LCD display screen, a mode switching button, a start / pause button, a wireless communication module, and a TYPE-C interface; the LCD display screen is used to display the current phototherapy plan, remaining irradiation time, and number of consecutive days of use; the wireless communication module is used to receive mode selection commands sent by external terminal devices; the TYPE-C interface is used to connect an external adapter for power supply, with an operating voltage of 20 V and an operating current of 2 A.

[0007] Preferably, the device further includes a heat sink, a metal back cover, and a temperature rise protection module. The heat sink is disposed on the back of the lamp panel, and the surface of the metal back cover is provided with heat dissipation fins. The temperature rise protection module stops the LED output when the housing temperature reaches a preset threshold. The temperature rise protection module includes a temperature sensor disposed on the back of the lamp panel or the inside of the back cover, and the temperature sensor is electrically connected to the control unit. When the detected temperature reaches the preset threshold, the control unit stops the LED output and alarms via an LCD display or an audible alert.

[0008] Preferably, the device further includes a voice recognition module and a protective eye mask; the voice recognition module is electrically connected to the control unit and is used to receive and recognize the user's voice commands; the preset irradiation time for any phototherapy program does not exceed 20 minutes and automatically stops after the preset time is reached.

[0009] A control method for the phototherapy device according to claim 1, characterized in that it includes: The control unit receives sensitive skin type information input by the user or an external terminal device. The sensitive skin type information is skin care classification information that is not for disease diagnosis purposes. When the sensitive muscle type information is vascular nerve hypersensitive type, the control unit calls and executes the first phototherapy plan; When the sensitive skin type information is barrier-damaged, the control unit invokes and executes the second phototherapy plan; When the sensitive skin type information is mixed, the control unit calls and executes the third phototherapy plan.

[0010] Preferably, the sensitive muscle type information is a type identifier pre-generated by an external terminal device, a user input module, or professional care advice, and the type identifier includes one of vascular nerve hypersensitivity, barrier damage, and mixed types.

[0011] Preferably, when the first phototherapy scheme is executed, 570 nm pure yellow light is output for 10 minutes, followed by composite light (Ⅰ) with a yellow-red energy density ratio of 7:3 at a calibrated distance of 10 cm for 5 minutes; when the second phototherapy scheme is executed, composite light (Ⅱ) with a yellow-red energy density ratio of 3:7 at a calibrated distance of 10 cm is output for 15 minutes; when the third phototherapy scheme is executed, composite light (Ⅲ) with a yellow-red energy density ratio of 5:5 at a calibrated distance of 10 cm is output for 15 minutes.

[0012] Preferably, after executing any phototherapy program, the control unit automatically stops the LED output when the preset irradiation time is reached, and prompts the user that the treatment is over through the LCD display or a prompt sound; the control unit records the cumulative irradiation time of the day and the end time of the last irradiation, and when the cumulative irradiation time reaches 30 minutes or less than 1 hour since the last irradiation, the phototherapy program is prohibited from being started and a prompt is output through the LCD display.

[0013] Preferably, the sensitive skin type information is obtained from a self-test questionnaire in a mini-program running on an external terminal device. The self-test questionnaire includes assessment questions on neurovascular hyperresponsiveness and barrier damage. The mini-program sends the sensitive skin type judgment result to the control unit via a wireless communication module.

[0014] Compared with the prior art, the present invention has the following beneficial effects: Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The invention adopts a dual-band infrared-free scheme, combining the nerve-soothing effect of 570 nm yellow light and the barrier-repairing effect of 630 nm red light in the same device, which helps to reduce the risk of heat stimulation in home care for sensitive skin. Unlike the three-band schemes containing infrared light disclosed in CN118987503A, this invention explicitly excludes infrared LED beads and is specifically designed for sensitive skin type-specific care scenarios.

[0015] (2) The sensitive skin type information is bound to the control logic of three preset light output schemes, so that the device can automatically match different yellow-red ratios according to the three states of vascular nerve hypersensitivity, barrier damage and mixed type, which overcomes the technical defects of the existing fixed light output mode that cannot cope with individual differences of sensitive skin.

[0016] (3) 7:3, 3:7 and 5:5 are defined as the target yellow-red energy density ratio at 10 cm and are achieved by factory calibration through independent PWM channels; the prototype can confirm the corresponding yellow-red energy density ratio through spectral measurement, which improves the repeatability and detectability of light output parameters and avoids the possible deviation when only the PWM duty cycle is used to describe the ratio.

[0017] (4) 160 yellow LEDs and 160 red LEDs are arranged alternately (preferably in a checkerboard pattern), and each LED is equipped with a focusing lens, which helps to improve the uniformity of light mixing in the facial illumination area. Silicon-based gallium nitride yellow LEDs have engineering advantages in wavelength accuracy (±2 nm), high electro-optical conversion efficiency and heat dissipation performance, which is conducive to the stable operation of high-density LED arrays.

[0018] Features such as automatic stop, temperature rise protection, eye protection structure, and voice interaction are included to meet the safety and operability requirements of home phototherapy devices. Attached Figure Description

[0019] Figure 1 This is a front view of the overall appearance of the phototherapy device of the present invention.

[0020] Figure 2 This is a schematic diagram of the LED arrangement on the lamp board of the present invention.

[0021] Figure 3 This is a schematic diagram of the combination of a single LED bead and a focusing lens in this invention.

[0022] Figure 4 This is a schematic diagram of the internal structure of the phototherapy device of the present invention.

[0023] Attached reference numerals: 1. Front panel; 2. Rear cover; 3. Lamp panel; 4. Condenser lens; 5. Lens plate; 6. Mounting plate; 7. LED beads; 8. Sound outlet. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] Example 1: Structure of the phototherapy device like Figures 1 to 4 As shown, the phototherapy device of the present invention has a flat plate structure. The housing includes a front panel 1 and a rear cover 2, which are interlocked to form a receiving cavity. The lamp plate 3, lens plate 5, and fixing plate 6 are disposed within the receiving cavity. The overall dimensions of the housing are approximately 300 mm × 218 mm × 13.8 mm, making it convenient for home use and storage.

[0027] The light panel 3 has 320 LED beads 7, of which 160 are yellow LED beads with a peak wavelength of 570 nm and 160 are red LED beads with a peak wavelength of 630 nm. A focusing lens 4 is positioned in front of each LED bead 7, fixed to a lens plate 5, to converge and collimate the light emitted by the LED beads, improving illumination uniformity and energy utilization. The front panel 1 has 320 light-transmitting holes, each corresponding to one of the 320 LED beads.

[0028] The rear cover 2 is provided with a sound outlet 8, and a speaker is provided in the cavity corresponding to the position of the sound outlet 8, which is used to emit start, pause, end or abnormal prompt sounds during operation. A magnetic component is also embedded in the inner side of the rear cover 2, which is used to cooperate with the bracket assembly so that the shell can be supported on the table at a predetermined angle.

[0029] The device is powered via an external adapter connected to a Type-C interface. The device's rated input is 20 V DC, and its rated operating current does not exceed 2 A. The external adapter can be a type-C PD adapter with a rated output power of at least 40 W, such as one supporting 20 V DC output, with an input voltage of 100-240 V AC. The device operates by turning on when powered on and off when unplugged. The casing also features an LCD display, a mode switching button, and a start / pause button. The LCD display shows the current phototherapy plan, remaining irradiation time, and number of consecutive days of use. The device can also be equipped with a wireless communication module, such as a Bluetooth module, for connection to external terminal devices such as mobile phones or tablets.

[0030] Example 2: LED Bead Selection and Arrangement The yellow LED bead uses a silicon-based gallium nitride (GaN-on-Si) LED chip with a peak wavelength of 570 nm ± 2 nm. The chip adopts an epitaxial structure consisting of a silicon substrate (Si(111)), a buffer layer, an n-type GaN layer, an InGaN / GaN multi-quantum-well active region, a p-type AlGaN layer, and a p-type GaN layer, and is grown using MOCVD technology. Compared with traditional AlGaInP yellow LEDs (590 nm, wavelength error greater than ±5 nm, and generally low electro-optical conversion efficiency), silicon-based gallium nitride 570 nm yellow LEDs have the following advantages: (1) higher wavelength accuracy (±2 nm), and its emission spectrum (half-width at half maximum 25-40 nm) can be adjacent to or cover the oxyhemoglobin-related absorption range (about 577 nm), and is within the range of yellow light bio-modulation band commonly used in public research; (2) in the preferred embodiment, it can have a higher electro-optical conversion efficiency; (3) no phosphor conversion, and a narrower half-width at half maximum spectral width (about 30 nm), avoiding light decay and color drift problems caused by phosphor degradation; (4) the thermal conductivity of silicon substrate (150 W / m·K) is better than that of sapphire (35 W / m·K), which is beneficial to the heat dissipation of high-density LED arrays.

[0031] It should be noted that the "peak wavelength" referred to in this invention is the wavelength corresponding to the maximum spectral power distribution in the LED emission spectrum, which can be directly measured using a spectroradiometer; the "dominant wavelength" is a colorimetric parameter calculated based on the CIE colorimetric diagram. These are different technical specifications. This invention uses the peak wavelength as a device specification and quality control parameter.

[0032] The red LED beads use red light chips with a peak wavelength of 630 nm. The yellow and red LED beads do not form an array together with the infrared LEDs; therefore, the lamp board described in this embodiment does not include 830-870 nm infrared light output.

[0033] 320 LED beads are arranged in a 20-row × 16-column matrix on the lamp board (3). In each row, two adjacent LED beads are red LED beads and yellow LED beads, respectively. As a preferred embodiment, the yellow LED beads and red LED beads in two adjacent rows are staggered by one lamp position, so that a checkerboard pattern of alternating red and yellow is formed in both the vertical and horizontal directions, so as to improve the uniformity of light mixing on the illumination surface.

[0034] Example 3: Control Unit and Three Phototherapy Solutions The control unit, comprising a microcontroller (MCU) and a memory, is housed within the housing cavity. A group of 160 yellow LED beads and a group of 160 red LED beads are respectively connected to an independent first constant current drive channel and a second constant current drive channel. The microcontroller controls the output of the two groups of LED beads separately via independent PWM signals.

[0035] When pure yellow light is required, the control unit illuminates only the yellow LED group, while the red LED group remains off. When composite light is required, the control unit illuminates both the yellow and red LED groups simultaneously and outputs light according to pre-calibrated PWM parameters, ensuring that the energy density of the yellow band at 10 cm corresponds to the energy density of the red band in a preset ratio. In this invention, the ratio of the three composite light sources is not a power ratio or PWM duty cycle, but rather an energy density ratio that can be measured and confirmed at 10 cm using a spectroradiometer in the prototype.

[0036] (I) First Phototherapy Program – Vascular and Nerve Hypersensitivity Type (Rapid Soothing Mode). This program is designed for users with sensitive skin characterized primarily by neurovascular hyperreactivity. The first phototherapy program first outputs pure yellow light with a peak wavelength of 570 nm for 10 minutes, then automatically switches to composite light (Ⅰ) with a yellow-red energy density ratio of 7:3 at a calibrated distance of 10 cm for 5 minutes, for a total irradiation time of 15 minutes. The design logic of this program is: first, use yellow light as the dominant output for soothing care, and then supplement it with a small amount of red light as a supplementary output for barrier-related care. At a calibrated distance of 10 cm, the target irradiance of the pure yellow light stage is approximately 8 mW / cm², and the target energy density is approximately 4.8 J / cm²; the target irradiance of the composite light (Ⅰ) stage is approximately 9.5 mW / cm², and the target energy density is approximately 2.85 J / cm², with a total energy density of approximately 7.65 J / cm² for a single session. This program mainly uses yellow light for soothing and is within the range of low-dose soothing care.

[0037] (II) Second Phototherapy Protocol – Barrier Damage Type (Barrier Regeneration Mode). This protocol is designed for users with sensitive skin characterized primarily by defects in the skin's physical barrier. The second phototherapy protocol outputs composite light (II) with a yellow-to-red energy density ratio of 3:7 at a calibrated distance of 10 cm for 15 minutes. The design logic of this protocol is: red light is the dominant output for barrier-related care, supplemented by yellow light for soothing care. At the calibrated distance of 10 cm, the target irradiance is approximately 11 mW / cm², and the total energy density per pulse is approximately 9.9 J / cm², of which red light energy is approximately 6.93 J / cm², referring to the commonly used red light care dose range in published studies (approximately 7 J / cm²), and yellow light energy is approximately 2.97 J / cm².

[0038] (III) Third Phototherapy Program – Hybrid Type (Stabilizing and Repairing Mode). This program is designed for users with mixed-type sensitive skin who simultaneously exhibit neurovascular hyperreactivity and barrier function deficiency. The third phototherapy program outputs composite light (Ⅲ) with a yellow-red energy density ratio of 5:5 at a calibrated distance of 10 cm for 15 minutes. The design logic of this program is to use a balanced output of red and yellow light, while simultaneously considering both soothing and barrier-related care. At the calibrated distance of 10 cm, the target irradiance is approximately 10.5 mW / cm², the total energy density of a single session is approximately 9.45 J / cm², and the red and yellow light are each approximately 4.73 J / cm².

[0039] The total energy density of all the above schemes is controlled within the low-dose nursing design range of about 10 J / cm². After the preset time is reached, the control unit automatically stops the LED output.

[0040] Example 4: Matching Sensitive Skin Type Information with Treatment Plan The sensitive skin type information described in this invention is non-disease diagnostic information used for selecting home care plans. This information can be obtained in the following ways: (1) the user makes a self-assessment based on the self-test guidelines provided in the device instruction manual or the mini-program; (2) the user completes the CAT and LAST simulation assessment questionnaire through the mini-program on the external terminal device, and the mini-program automatically outputs the assessment results and sends them to the control unit through the wireless communication module; (3) the user manually selects the corresponding type after obtaining care advice from a professional institution.

[0041] In professional institutions or skin research settings, LAST and CAT can be used as reference methods for generating typing information. The specific criteria for typing are: LAST positive and CAT negative are classified as barrier-damaged type; LAST negative and CAT positive are classified as vascular-neural hypersensitive type; and LAST and CAT double positive are classified as mixed type. The typing information can also be generated from user self-testing questionnaires, external terminal devices, or professional care advice. LAST and CAT are skin condition assessment methods not for disease diagnosis purposes. The control method of this invention does not require the device to perform LAST or CAT test steps, nor is it intended for disease diagnosis or treatment.

[0042] When the type information indicates that the user's condition is primarily neurovascular hyperresponsiveness (e.g., CAT positive, or frequent burning, flushing, or worsening symptoms upon exposure to heat), the control unit matches the first phototherapy plan. When the type information indicates that the user's condition is primarily barrier damage (e.g., LAST positive, or frequent dryness, tightness, peeling, or stinging sensation when applying skincare products), the control unit matches the second phototherapy plan. When the type information indicates that the user has both of the above symptoms (LAST and CAT double positive, or simultaneous flushing and dryness / stirring), the control unit matches the third phototherapy plan. Users can also manually select any phototherapy plan via a button or a mini-program.

[0043] Example 5: Operation Flow, Mode Switching, and Interactive Control After the device is powered on, it defaults to the operating mode it was in during the last shutdown and enters standby mode. A short press of the mode switch button cycles through the modes in a preset order: Rapid Soothing Mode → Barrier Regeneration Mode → Stabilization and Repair Mode → Return to Rapid Soothing Mode. A long press of the mode switch button for 3 seconds returns to the previous mode. In standby mode, pressing the start / pause button starts the device in the currently selected mode; pressing it again pauses operation; pressing it again resumes operation. Throughout operation, the LCD screen displays the remaining illumination time for the current mode. After the preset time is reached, the device automatically stops light output and emits a warning sound.

[0044] The device can also be equipped with a voice recognition module, which is electrically connected to the control unit. The memory pre-stores voice command templates corresponding to various operations, including "Power on," "Power off," "Start," "Pause," "Next mode," "Previous mode," "Select rapid soothing mode," "Select barrier regeneration mode," and "Select stabilization and repair mode." Each mode can also have its operating time set via voice commands, with a maximum setting time of 20 minutes.

[0045] The device establishes a wireless connection with external terminal devices through a wireless communication module (such as a Bluetooth module). The accompanying mini-program provides the following functions: (1) Sensitive skin type self-test - built-in CAT and LAST simulation assessment questionnaires. The CAT simulation assessment focuses on symptoms such as facial flushing, burning sensation, and aggravation when exposed to heat (corresponding to TRPV1 pathway hyperresponsiveness). The LAST simulation assessment focuses on symptoms such as stinging sensation, dryness and peeling, and intolerance to skin care products (corresponding to barrier function deficiency). After completing the questionnaire, the judgment result is automatically output and sent to the device control unit; (2) Remote mode selection - users can directly select any working mode on the mini-program interface; (3) Remote control - start, pause and shut down; (4) Usage record viewing - record and visualize the mode, duration, date and number of consecutive days of use each time.

[0046] Example 6: Safety Controls and Usage Restrictions To reduce usage risks, the device is equipped with a single-use automatic stop, temperature rise protection, and eye protection structure. The temperature rise protection follows the design principles of GB / T 4706.15-2024 "Safety of household and similar electrical appliances - Part 15: Particular requirements for skin and hair care appliances." When operating continuously at maximum power in an environment of 30°C, the temperature rise protection module reduces the risk of overheating of accessible surfaces. The temperature rise protection module includes a temperature sensor located on the back of the lamp panel or inside the rear cover, electrically connected to the control unit. When the detected temperature reaches a preset threshold, the control unit stops the LED output and issues an alarm via the LCD display or an audible alert to reduce the risk of overheating of accessible surfaces. Specific temperature rise limits are subject to the test report of the prototype according to applicable safety standards. Users should maintain a recommended irradiation distance of 10-20 cm. First-time users or those with high reactivity can start at 15-20 cm and gradually adjust to 10 cm as the skin adapts. The cumulative irradiation time on the same area on the same day should not exceed 30 minutes, and the interval between two uses should be no less than 1 hour.

[0047] Before use, users should remove facial makeup, clean the area to be irradiated, remove metal jewelry, glasses, and contact lenses, and wear protective eyewear. Do not look directly at the LED light source for extended periods during use. After use, keep the main unit and adapter dry. Slight warmth and dryness of the skin after use are normal.

[0048] The device should be used and stored in an environment with an operating temperature of 0℃ to +40℃ and an operating humidity below 85%RH, and a storage temperature of -10℃ to +50℃ and a storage humidity below 85%RH. Avoid using or storing the device near fire sources, heating equipment, or high-temperature environments; avoid using it near water sources or while showering; avoid unauthorized disassembly or modification; and avoid cleaning with corrosive solvents. If any abnormalities such as smoke, unusual noises, or odors occur during operation, immediately unplug the power adapter and stop using the device.

[0049] Photosensitive contraindications: This device is not suitable for individuals with porphyria, photosensitivity diseases (such as solar urticaria, acute phase of polymorphic light eruption), or those currently using photosensitizing drugs (such as tetracyclines, fluoroquinolones, sulfonamides, thiazide diuretics, retinoids, etc.). This device uses GB / T 20145-2006 "Photobiological Safety of Lamps and Lamp Systems" (equivalent to IEC 62471) as the photobiological safety design reference. The design verification for the potential light radiation hazards of the 570 nm yellow LED and 630 nm red LED is as follows.

[0050] I. Design of Yellow and Red LED Light Sources. This device uses 570 nm yellow LEDs and 630 nm red LEDs, without ultraviolet or infrared LEDs. The output power density, recommended irradiation distance, and single irradiation time of yellow and red light are all limited according to low-dose nursing scenarios to reduce the risks of blue light hazards, retinal thermal hazards, infrared radiation hazards to the eyes, thermal hazards to the skin, and ultraviolet hazards.

[0051] II. Usage Restrictions. The device is designed to reduce photobiological safety risks under reasonably foreseeable usage conditions by limiting the recommended usage distance to 10-20 cm, the duration of a single irradiation session to no more than 20 minutes, the cumulative daily irradiation time for the same area to no more than 30 minutes, and the interval between two uses to no less than 1 hour. It is also equipped with automatic stop and eye protection.

[0052] III. No Infrared LED Design. This device does not contain infrared LED beads and does not have an independent infrared radiation source. The 780-3000 nm wavelength range may only come from the long-wave tail radiation of yellow and red LEDs; the actual infrared radiation level shall be based on the test results of the finalized prototype.

[0053] IV. Overall Photobiological Safety Design. This device uses RG0 as the photobiological safety design target. Based on the evaluation method of GB / T20145-2006 / IEC 62471, the design verification was conducted on the potential blue light hazards, retinal thermal hazards, infrared radiation hazards to the eyes, skin thermal hazards, and ultraviolet hazards associated with the 570 nm yellow LED and 630 nm red LED. RG0 is the photobiological safety design target for this device; the actual design will be based on the complete test report of the finalized prototype according to GB / T 20145-2006 / IEC 62471.

[0054] V. Electrical Safety and Biocompatibility Compliance Design. The electrical safety design of this device is based on GB / T 4706.1-2024 "Safety of household and similar electrical appliances - Part 1: General requirements", and incorporates the safety requirements related to skin care, light-emitting skin appliances, and skin beauty appliances in GB / T 4706.15-2024 "Particular requirements for skin and hair care appliances", GB / T 4706.85-2024 "Particular requirements for light-emitting skin appliances", and GB / T 4706.118-2024 "Particular requirements for skin beauty appliances". If the final light source intensity or regulatory classification of the product involves high-intensity light source beauty appliances, a further applicability assessment will be conducted according to GB / T 4706.119-2024. The product uses a TYPE-C interface for power supply (20 VDC / 2 A), which falls within the safe extra-low voltage (SELV) power supply range and does not require direct connection to mains power. The device is equipped with a temperature rise shutdown protection system, automatically stopping output when the housing temperature reaches a preset threshold. Facial contact materials can be biocompatibility evaluated according to GB / T 16886 series standards. The device is equipped with an integrated goggle shield to block direct LED light from entering the user's eyes, further reducing the risk of eye radiation. Actual safety compliance is subject to the prototype testing report.

[0055] Example 7: Public Research and Explanation of Technical Reasonableness This embodiment is used to illustrate the technical basis of the wavelength selection, ratio control and sensitive skin care logic of the present invention. It does not take specific care effect values ​​as necessary limitations of the claims, nor does it directly equate external research with proof that the device of the present invention has completed all clinical trials.

[0056] A publicly available study by Yi et al. (Lasers in Medical Science, 2025) compared the effects of 570 nm and 590 nm yellow light on facial photoaging under combined red light and 850 nm infrared LED conditions. This study showed that, with fixed red and infrared light parameters, the 570 nm group exhibited improvements in indicators such as GSP scores, wrinkles, and brown spots, supporting the selection of the 570 nm yellow light wavelength relative to 590 nm in terms of photobiological modulation efficiency. It should be noted that this study focused on photoaging and included the infrared band, which is a different application scenario from the infrared-free dual-band sensitive skin care method described in this invention.

[0057] A publicly available study by He et al. (Photodermatology, Photoimmunology & Photomedicine, 2026) evaluated the effects of 590 nm yellow light and 590 / 630 nm dual-wavelength LEDs on sensitive skin. This single-center, prospective, randomized controlled trial (n=30) showed that the LED irradiation group improved compared to the control group in terms of SS-10 sensitive skin symptom scores, erythema index, melanin index, transepidermal water loss, and lactic acid stinging test. No adverse events were reported throughout the trial. This study can serve as a publicly available technical reference for the use of yellow light and red-yellow light combinations in sensitive skin care; however, its specific wavelengths, device structures, classification control logic, and output parameters are not entirely identical to those of this invention and cannot be equated with direct clinical validation of the specific device and parameter combinations of this invention.

[0058] The improvements of this invention compared to the aforementioned published research are as follows: First, it adopts a yellow-red dual-band structure without infrared light, specifically designed for sensitive skin care, reducing the risk of heat stimulation; Second, the output ratio of yellow and red light is set to the target yellow-red energy density ratio at 10 cm, which can be confirmed by spectral measurement in the prototype, improving the repeatability and detectability of light output parameters; Third, the three output schemes are bound to the control logic of sensitive skin care classification information based on LAST / CAT, realizing differentiated control based on classification, rather than fixed mode output; Fourth, it adopts a safety structure design suitable for home devices, including automatic stop, temperature control, eye protection, and voice interaction.

[0059] This embodiment provides example values ​​of target power density and energy density for the yellow light band (570±2 nm) and red light band (630±10 nm) that can be used for PWM factory calibration of the phototherapy device of the present invention at a calibration distance of 10 cm according to the target yellow-red energy density ratio (10:0, 7:3, 3:7, 5:5). This is used to illustrate the feasibility of the calibration energy density ratio described in the present invention in prototype design and control parameter setting.

[0060] Table 1: Band-specific target power density and energy density at 10 cm for different yellow-red energy density ratios (example values)

[0061] Note: ① The above values ​​are example values ​​calculated based on the target total energy density, the target yellow-red energy density ratio, and the irradiation duration, and are not PWM duty cycles; the PWM duty cycle is the actual control parameter stored in the control unit after factory calibration. ② The prototype can be verified by performing spectroradiometer integration in the 570±2 nm and 630±10 nm bands. When the power density unit is mW / cm² and the irradiation duration unit is s, the energy density (J / cm²) = power density × irradiation duration / 1000. Ordinary broadband radiometers should not be used alone as the basis for confirming the energy ratio of different bands.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A phototherapy device for sensitive skin type-specific care, characterized in that, It includes a housing, a lamp board disposed within the housing, LED beads disposed on the lamp board, and a control unit electrically connected to the LED beads; The LED beads consist only of yellow LED beads and red LED beads, and do not include infrared LED beads; wherein, the number of yellow LED beads is 160, with a peak wavelength of 570 nm±2 nm, and the number of red LED beads is 160, with a peak wavelength of 630 nm±10 nm. The control unit is configured to receive sensitive skin type information and, based on the sensitive skin type information, select the corresponding solution from at least three phototherapy options: The first phototherapy regimen corresponds to vascular and nerve hypersensitive sensitive skin. First, pure yellow light from the yellow LED beads is output for 10 minutes, and then composite light (Ⅰ) with a fixed energy density ratio of 7:3 between yellow light and red light at a calibrated distance of 10 cm is output for 5 minutes. The second phototherapy regimen, corresponding to barrier-damaged sensitive skin, involves outputting composite light (II) with a fixed energy density ratio of 3:7 for 15 minutes at a calibrated distance of 10 cm, consisting of yellow light and red light at a calibrated distance of 10 cm; The third phototherapy regimen, corresponding to mixed sensitive skin, outputs a composite light (Ⅲ) for 15 minutes at a calibrated distance of 10 cm, with a 5:5 ratio of yellow light to red light energy density.

2. A phototherapy device for sensitive skin type-specific care according to claim 1, characterized in that, The yellow LED beads use gallium nitride (GaN-on-Si) chips on silicon, with a full width at half maximum (FWHM) of 25-40 nm.

3. The phototherapy device according to claim 1, characterized in that, The 320 LED beads are arranged in a 20-row × 16-column matrix; in each row, two adjacent LED beads are a yellow LED bead and a red LED bead, respectively.

4. A phototherapy device for sensitive skin type care according to claim 3, characterized in that, The yellow LED beads in two adjacent rows are staggered by one position from the red LED beads, so that the light panel forms a checkerboard pattern of alternating red and yellow.

5. A phototherapy device for sensitive skin type-specific care according to claim 1, characterized in that, The control unit includes a microcontroller, a memory, a first constant current drive channel, and a second constant current drive channel. The first constant current drive channel is used to drive the yellow LED bead group, and the second constant current drive channel is used to drive the red LED bead group. The microcontroller adjusts the output of the two groups of LED beads respectively through independent PWM signals to achieve the calibrated energy density ratio.

6. A phototherapy device for sensitive skin type-specific care according to claim 1 or 5, characterized in that, The 7:3, 3:7, and 5:5 ratios represent the target yellow-red energy density ratios. The calibrated energy density ratio is the ratio of the energy density of the yellow band to the energy density of the red band corresponding to the factory calibration parameters set according to the target yellow-red energy density ratio. In the prototype, the calibrated energy density ratio can be confirmed by band-wise measurement using a spectroradiometer at a distance of 10 cm from the LED light-emitting surface, and the calibrated energy density ratio is within the preset allowable deviation range of the target yellow-red energy density ratio. The preset allowable deviation range is that the relative deviation of the calibrated energy density ratio relative to the target yellow-red energy density ratio does not exceed ±10%. The PWM duty cycle is the factory calibration parameter used to achieve the calibrated energy density ratio.

7. A phototherapy device for sensitive skin type-specific care according to claim 1, characterized in that, The first phototherapy regimen has an irradiance of approximately 8 mW / cm² and an energy density of approximately 4.8 J / cm² in the pure yellow light stage at a distance of 10 cm, and an irradiance of approximately 9.5 mW / cm² and an energy density of approximately 2.85 J / cm² in the composite light (Ⅰ) stage, with a total energy density of approximately 7.65 J / cm² in a single session. The second phototherapy regimen has an irradiance of approximately 11 mW / cm² at a distance of 10 cm and a total energy density of approximately 9.9 J / cm² in a single session, of which approximately 6.93 J / cm² is red light energy. The third phototherapy regimen has an irradiance of approximately 10.5 mW / cm² at a distance of 10 cm and a total energy density of approximately 9.45 J / cm² in a single session. The above irradiance and energy density are example values, and the allowable deviation range is ±10%.

8. A phototherapy device for sensitive skin type care according to claim 1, characterized in that, The housing includes a front panel, a rear cover, a lamp panel, a condenser lens, a lens plate, and a fixing plate. Each LED bead is provided with a corresponding condenser lens, which is fixed on the lens plate. The lamp panel and the lens plate are fixed relative to each other by the fixing plate. The front panel has 320 light-transmitting holes, which correspond one-to-one with the 320 LED beads.

9. A phototherapy device for sensitive skin type-specific care according to claim 1, characterized in that, The device also includes an LCD display, a mode switching button, a start / pause button, a wireless communication module, and a TYPE-C interface; the LCD display is used to display the current phototherapy plan, remaining irradiation time, and number of consecutive days of use; the wireless communication module is used to receive mode selection commands sent by external terminal devices; the TYPE-C interface is used to connect an external adapter for power supply, with an operating voltage of 20 V and an operating current of 2 A.

10. A phototherapy device for sensitive skin type care according to claim 1, characterized in that, The device further includes a heat sink, a metal back cover, and a temperature rise protection module. The heat sink is disposed on the back of the lamp panel, and the surface of the metal back cover is provided with heat dissipation fins. The temperature rise protection module stops the LED output when the housing temperature reaches a preset threshold. The temperature rise protection module includes a temperature sensor disposed on the back of the lamp panel or the inside of the back cover, and the temperature sensor is electrically connected to the control unit. When the detected temperature reaches the preset threshold, the control unit stops the LED output and alarms via an LCD display or an audible alert.

11. A phototherapy device for sensitive skin type care according to claim 1, characterized in that, The device also includes a voice recognition module and a protective eye mask; the voice recognition module is electrically connected to the control unit and is used to receive and recognize the user's voice commands; the preset irradiation time for any phototherapy program does not exceed 20 minutes and automatically stops after the preset time is reached.

12. A control method based on the phototherapy device of claim 1, characterized in that, include: The control unit receives sensitive skin type information input by the user or an external terminal device. The sensitive skin type information is skin care classification information that is not for disease diagnosis purposes. When the sensitive muscle type information is vascular nerve hypersensitive type, the control unit calls and executes the first phototherapy plan; When the sensitive skin type information is barrier-damaged, the control unit invokes and executes the second phototherapy plan; When the sensitive skin type information is mixed, the control unit calls and executes the third phototherapy plan.

13. The control method according to claim 12, characterized in that, The sensitive muscle type information is a type identifier pre-generated by an external terminal device, user input module, or professional care advice. The type identifier includes one of the following: vascular nerve hypersensitivity, barrier damage, and mixed type.

14. The control method according to claim 12, characterized in that, When the first phototherapy regimen is executed, 570 nm pure yellow light is output for 10 minutes, followed by composite light (Ⅰ) with a yellow-red energy density ratio of 7:3 at a calibrated distance of 10 cm for 5 minutes; when the second phototherapy regimen is executed, composite light (Ⅱ) with a yellow-red energy density ratio of 3:7 at a calibrated distance of 10 cm is output for 15 minutes; when the third phototherapy regimen is executed, composite light (Ⅲ) with a yellow-red energy density ratio of 5:5 at a calibrated distance of 10 cm is output for 15 minutes.

15. The control method according to claim 12, characterized in that, After executing any phototherapy program, the control unit automatically stops the LED output when the preset irradiation time is reached, and prompts the user that the treatment is over through the LCD display or a prompt sound. The control unit records the cumulative irradiation time for the day and the end time of the last irradiation. When the cumulative irradiation time reaches 30 minutes or less than 1 hour since the last irradiation, the phototherapy program is prohibited from being started and a prompt is output on the LCD display.

16. The control method according to claim 13, characterized in that, The sensitive skin type information is obtained from a self-test questionnaire in a mini-program running on an external terminal device. The self-test questionnaire includes assessment questions on neurovascular hyperresponsiveness and barrier damage. The mini-program sends the sensitive skin type judgment results to the control unit via a wireless communication module.

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