Radio frequency system for automatically regulating output energy by measuring skin impedance

Abstract

The present application provides a radio frequency system for automatically regulating output energy by measuring skin impedance. According to the method, a forward voltage and a reverse voltage of radio frequency energy acting on the skin are measured; a control module adjusts the duty cycle of a second PWM control module on the basis of the forward voltage and the reverse voltage; the second PWM control module regulates an output voltage of a main power supply on the basis of the adjusted duty cycle, so as to regulate radio frequency energy outputted by the radio frequency system; and thus, the radio frequency energy acting on the skin can be automatically regulated without manual regulation, thereby greatly improving the radio frequency energy output accuracy of the radio frequency system.

Description

A radio frequency system that automatically adjusts output energy based on skin impedance detection

[0001] This application claims priority to Chinese Patent Application No. 202410905828.5, filed on July 8, 2024, entitled "A Radio Frequency System for Automatically Adjusting Output Energy for Detecting Skin Impedance", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of radio frequency technology, and more specifically, to a radio frequency system that automatically adjusts output energy based on the detection of skin impedance. Background Technology

[0003] Currently, radiofrequency (RF) systems are used in the medical aesthetics field as radiofrequency treatment devices for procedures such as wrinkle removal, ablation, skin tightening, and hair removal. The specific treatment process involves aiming the RF system at the patient's skin to be treated, and then controlling the output of RF energy to perform the treatment. During this process, the amount of RF energy output relies heavily on the doctor's experience and the patient's perception, resulting in relatively low precision in the RF energy output. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this application is to provide a radio frequency system that automatically adjusts output energy based on skin impedance detection.

[0005] In a first aspect, embodiments of this application provide a radio frequency system for automatically adjusting output energy based on skin impedance detection, comprising: a main power supply, a power conversion and voltage regulation module, a first PWM control module, a second PWM control module, a control module, a PWM signal output module, a power amplification module, an active crystal oscillator module, a first processing module, a second processing module, and a radio frequency output terminal;

[0006] The main power supply is connected to the power conversion and voltage regulation module, the first PWM control module, the second PWM control module, and the power amplification module, respectively. The power conversion and voltage regulation module is also connected to the control module. The first PWM control module is also connected to the PWM signal output module and the power amplification module, respectively. The second PWM control module is also connected to the control module. The control module is also connected to the PWM signal output module, the first processing module, and the second processing module. The power amplification module is also connected to the active crystal oscillator module and the first processing module. The first processing module is also connected to the second processing module and the RF output terminal.

[0007] The radio frequency (RF) signal output by the active crystal oscillator module is amplified by the power amplifier module and processed by the first processing module, and then outputs RF energy at the RF output terminal, which acts on the skin. The first processing module sends a detection signal to the RF energy to detect the forward and reverse voltages of the RF energy, and feeds back the detected forward and reverse voltages to the control module. The control module adjusts the duty cycle of the second PWM control module according to the forward and reverse voltages. The second PWM control module adjusts the output voltage of the main power supply according to the adjusted duty cycle, thereby regulating the RF energy output by the RF system.

[0008] In the solution provided by the first aspect of this application embodiment, the radio frequency signal output by the active crystal oscillator module is amplified by a power amplifier module and processed by a first processing module, and then outputs radio frequency energy at the radio frequency output terminal to act on the skin. The first processing module sends a detection signal to the radio frequency energy to detect the forward and reverse voltages of the radio frequency energy, and feeds back the detected forward and reverse voltages to the control module. The control module adjusts the duty cycle of the second PWM control module according to the forward and reverse voltages. The second PWM control module adjusts the output voltage of the main power supply according to the adjusted duty cycle, thereby regulating the radio frequency energy output by the radio frequency system. Compared with the related technology where the magnitude of the radio frequency energy output by the radio frequency system is mainly adjusted based on the doctor's experience and the patient's feelings, this method can detect the forward and reverse voltages of the radio frequency energy acting on the skin. The control module adjusts the duty cycle of the second PWM control module according to the forward and reverse voltages, and the second PWM control module adjusts the output voltage of the main power supply according to the adjusted duty cycle, thereby regulating the radio frequency energy output by the radio frequency system. This allows for automatic regulation of the radio frequency energy acting on the skin without manual adjustment, greatly improving the accuracy of the radio frequency energy output by the radio frequency system.

[0009] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0011] Figure 1 shows a schematic diagram of the structure of a radio frequency system for automatically adjusting output energy based on skin impedance according to an embodiment of this application;

[0012] Icons: 100, Main power supply; 102, Power conversion and voltage regulation module; 104, First PWM control module; 106, Second PWM control module; 108, Control module; 110, PWM signal output module; 112, Power amplifier module; 114, Active crystal oscillator module; 116, First processing module; 118, Second processing module; 120, RF output terminal. Detailed Implementation

[0013] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", 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 application and 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 application.

[0014] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0015] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0016] Currently, radiofrequency (RF) systems are used in the medical aesthetics field as radiofrequency treatment devices for procedures such as wrinkle removal, ablation, skin tightening, and hair removal. The specific treatment process involves aiming the RF system at the patient's skin to be treated, and then controlling the output of RF energy to perform the treatment. During this process, the amount of RF energy output relies heavily on the doctor's experience and the patient's perception, resulting in relatively low precision in the RF energy output.

[0017] Based on this, this embodiment proposes a radio frequency (RF) system that automatically adjusts output energy by detecting skin impedance. The RF signal output from the active crystal oscillator module is amplified by a power amplifier module and processed by a first processing module, resulting in RF energy that acts on the skin. The first processing module sends a detection signal to the RF energy to detect the forward and reverse voltages, and feeds the detected forward and reverse voltages back to the control module. The control module adjusts the duty cycle of the second PWM control module based on the forward and reverse voltages. The second PWM control module then adjusts the output voltage of the main power supply based on the adjusted duty cycle, thereby regulating the RF energy output by the RF system. This system can automatically adjust the RF energy acting on the skin without manual adjustment, greatly improving the accuracy of the RF energy output by the RF system.

[0018] 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 embodiments.

[0019] Example

[0020] Referring to the structural schematic diagram of the radio frequency system for automatically adjusting output energy based on skin impedance detection shown in Figure 1, this embodiment proposes a radio frequency system for automatically adjusting output energy based on skin impedance detection, including: a main power supply 100, a power conversion and voltage regulation module 102, a first PWM control module 104, a second PWM control module 106, a control module 108, a PWM signal output module 110, a power amplification module 112, an active crystal oscillator module 114, a first processing module 116, a second processing module 118, and a radio frequency output terminal 120.

[0021] After the main power supply 100 is powered on, it outputs a 24-volt (V) DC voltage to provide operating power for the entire radio frequency system and the power conversion and voltage regulation module 102. The main power supply 100 outputs a 48V DC voltage to the power amplifier module 112 by default. When the control module 108 receives a radio frequency therapy signal, the control module 108 modulates the duty cycle of the second PWM control module 106 to 5%. The second PWM control module 106 operates and adjusts the output voltage of the main power supply 100 to 4VDC. At this time, the output of the first PWM control module 104 is 0, and the PWM signal output module 110 does not work. At this time, the first PWM control module 104 outputs 5VDC to control the operating mode of the power amplifier module 112 and the first processing module 116.

[0022] The main power supply 100 is connected to the power conversion and voltage regulation module 102, the first PWM control module 104, the second PWM control module 106, and the power amplifier module 112, respectively. The power conversion and voltage regulation module 102 is also connected to the control module 108. The first PWM control module 104 is also connected to the PWM signal output module 110 and the power amplifier module 112, respectively. The second PWM control module 106 is also connected to the control module 108. The control module 108 is also connected to the PWM signal output module 110, the first processing module 116, and the second processing module 118. The power amplifier module 112 is also connected to the active crystal oscillator module 114 and the first processing module 116. The first processing module 116 is also connected to the second processing module 118 and the radio frequency output terminal 120.

[0023] The radio frequency signal output by the active crystal oscillator module 114 is amplified by the power amplifier module 112 and processed by the first processing module 116, and then outputs radio frequency energy at the radio frequency output terminal 120, which acts on the skin. The first processing module 116 sends a detection signal to the radio frequency energy to detect the forward and reverse voltages of the radio frequency energy, and feeds back the detected forward and reverse voltages to the control module 108. The control module 108 adjusts the duty cycle of the second PWM control module 118 according to the forward and reverse voltages. The second PWM control module 118 adjusts the output voltage of the main power supply 100 according to the adjusted duty cycle, thereby regulating the radio frequency energy output by the radio frequency system.

[0024] Here, the power conversion and voltage regulation module 102, the first PWM control module 104, the second PWM control module 106, the PWM signal output module 110, the power amplification module 112, the active crystal oscillator module 114, the first processing module 116, and the second processing module 118 are composed of existing circuit structures, which will not be described in detail here.

[0025] The control module 108 may be, but is not limited to, a processor, a microprocessor, or a microcontroller.

[0026] The main power supply 100 converts the incoming AC power into DC power to supply the entire RF system. The voltage output by the main power supply 100 can be adjusted by the second PWM control module. The voltage output by the main power supply 100 is supplied to the power amplifier module 112.

[0027] The power conversion and voltage regulation module 102 converts 24V voltage to 5V voltage and 5V voltage to 3.3V voltage to provide power to the control module 108 and other circuits, and electrically isolates the control module 108 and other circuits from the main power supply 100.

[0028] The first PWM control module 104 provides a reference power supply to the power amplifier module 112 and generates a PWM1 modulation signal to control the radio frequency output mode.

[0029] The control module 108 is the core unit module of the entire radio frequency system, which can detect the positive voltage AD1. FWD and reverse voltage AD1 REF The calculation process is performed to obtain the radio frequency reflection coefficient ρ, and then the load impedance is calculated based on the radio frequency reflection coefficient ρ; it can also convert the detected analog voltage signal V AD2 The calculation process is performed to obtain the phase difference angle θ between the output RF voltage and current. Then, the load resistance value is calculated based on the phase angle of the voltage and current in the RF system loop and the load impedance in the RF system loop. Finally, the duty cycle of the second PWM control module is adjusted according to the output power value corresponding to the load resistance value.

[0030] In most counting circuits, the load impedance is calculated by detecting voltage and current. This method works fine for purely resistive loads, but it is completely incorrect for capacitive or inductive loads, especially in high-frequency or radio frequency circuits.

[0031] In the radio frequency system for automatically adjusting output energy by detecting skin impedance proposed in this embodiment, the load impedance is determined by detecting the phase difference angle θ between the radio frequency reflection coefficient and the output radio frequency voltage and current in the radio frequency system loop. This method is simple, reliable and highly accurate, especially in high frequency or radio frequency circuits.

[0032] The active crystal oscillator module 114 provides a signal source to the power amplifier module 112.

[0033] The power amplifier module 112 amplifies the RF signal (sine wave signal) emitted by the active crystal oscillator module 114 to provide power for the subsequent RF output.

[0034] The first processing module 116 includes: an RF output filter circuit, an impedance matching circuit, a directional coupler, and a voltage and current transformer; wherein, the function of the impedance matching circuit is to achieve a complete match between the load impedance and the characteristic impedance in the loop, so that the RF power can be transmitted to the load end to the maximum extent; the function of the directional coupler is to detect the positive voltage AD1 in the RF system loop. FWD and reverse voltage AD1 REFThe function of voltage and current transformers is to detect the phase difference between voltage and current in the circuit of a radio frequency system.

[0035] In one embodiment, in the first processing module 116, an RF output filter circuit, an impedance matching circuit, a directional coupler, and a voltage and current transformer are connected in sequence.

[0036] The RF output filter circuit is also connected to the power amplifier module 112; the voltage and current transformers are also connected to the RF output terminal 120 and the second processing module 118, respectively.

[0037] In this embodiment, the term "phase difference between voltage and current in the loop of the radio frequency system" has the same meaning as the aforementioned terms "phase difference angle θ between output radio frequency voltage and current" and "phase angle of voltage and current in the loop of the radio frequency system".

[0038] The second processing module 118 mainly includes: a JK trigger phase detector filter circuit and a zero-crossing comparator circuit; the second processing module 118 can convert the voltage and current phase difference in the RF system loop detected by the first processing module 116 into an analog voltage signal V. AD2 This makes it convenient for the control module 108 to read the phase difference, especially in radio frequency circuits where the control module 108 cannot directly read the phase difference. The advantages of this circuit are obvious.

[0039] In one embodiment, in the second processing module 118, the JK trigger phase detector filter circuit and the zero-crossing comparator circuit are connected. The JK trigger phase detector filter circuit is also connected to the control module 108, and the zero-crossing comparator circuit is also connected to the voltage and current transformer.

[0040] Currently, most methods for detecting voltage and current phase differences involve measuring the voltage and current waveforms separately using an oscilloscope and then reading the waveforms. This method suffers from significant errors, is inaccurate, and is inconvenient, especially in radio frequency (RF) circuits. The RF system for automatically adjusting output energy based on skin impedance proposed in this embodiment extracts the voltage and current signals separately using voltage and current transformers in the first processing module 116. Then, a zero-crossing comparator circuit is used to obtain the phase angle of the voltage and current in the RF system loop. Finally, the JK-triggered phase detector filter circuit in the second processing module 118 processes the signals to obtain the analog voltage signal V. AD2 It is accurate and easy to operate, and is particularly suitable for use in high-frequency or radio frequency circuits.

[0041] The PWM signal output module 110 mainly controls the radio frequency signal output mode. It controls the radio frequency output mode by outputting a PWM1 modulation signal (4Hz 80% duty cycle) through the control module 108. First, the radio frequency energy is output for 200 milliseconds (ms), and then the radio frequency energy is turned off for 50ms. The purpose is that the treatment time of a radio frequency pulse group is 200ms, which is shorter than the nerve induction time of 230ms-250ms, so that the nerve potential does not have time to react. Therefore, it can reduce the pain of the skin area where the radio frequency energy is applied.

[0042] The second PWM control module 106 is mainly used to adjust the output voltage of the main power supply 100 in order to adjust the output energy of the subsequent RF stage. The duty cycle of the second PWM control module is mainly determined by detecting the power value corresponding to the impedance value.

[0043] The control module adjusts the duty cycle of the second PWM control module according to the forward voltage and the reverse voltage, including the following specific steps:

[0044] The control module calculates the radio frequency reflection coefficient based on the forward voltage and the reverse voltage;

[0045] Obtain the characteristic impedance value, and calculate the load impedance in the loop of the radio frequency system based on the characteristic impedance value and the radio frequency reflection coefficient;

[0046] The phase angles of the voltage and current in the loop of the radio frequency system are calculated;

[0047] Based on the calculated phase angle of the voltage and current in the circuit of the radio frequency system and the load impedance in the circuit of the radio frequency system, the load resistance value of the skin subjected to the radio frequency energy is calculated.

[0048] The duty cycle of the second PWM control module is adjusted based on the calculated load resistance value.

[0049] Here, the first processing module is specifically used for:

[0050] Detect voltage and current signals in the circuit of the radio frequency system;

[0051] By comparing the phase of the voltage signal and the phase of the current signal, the phase difference between the phase of the voltage signal and the phase of the current signal is obtained.

[0052] The second processing module is specifically used for:

[0053] The phase difference is converted into an analog voltage signal, and the analog voltage signal is sent to the control module.

[0054] The control module calculates the phase angle of the voltage and current in the loop of the radio frequency system, including:

[0055] Obtain the reference voltage;

[0056] The phase angle of the voltage and current in the RF system loop can be calculated using the following formula: θ = V AD2 *4π / Vm

[0057] Where θ represents the phase angle of the voltage and current in the loop of the radio frequency system; V AD2 Vm represents the analog voltage signal; Vm represents the reference voltage.

[0058] In one implementation, the reference voltage is 5V.

[0059] Optionally, the first processing module is further specifically used for:

[0060] Detect the forward and reverse voltages in the circuit of the radio frequency system;

[0061] The detected positive and reverse voltages in the circuit of the radio frequency system are sent to the control module.

[0062] Specifically, the control module calculates the radio frequency reflection coefficient based on the forward voltage and the reverse voltage, including:

[0063] The standing wave ratio (SWR) in the loop of the radio frequency system is calculated using the following formula: SWR = (AD1) FWD +AD1 REF ) / (AD1 FWD -AD1 REF )

[0064] Wherein, SWR represents the standing wave ratio in the RF system loop; AD1 FWD Indicates forward voltage; AD1 REF Indicates reverse voltage;

[0065] The radio frequency reflection coefficient is calculated using the following formula: ρ=(SWR-1) / (SWR+1)

[0066] Where ρ represents the radio frequency reflection coefficient.

[0067] Specifically, the control module calculates the load impedance in the loop of the radio frequency system based on the characteristic impedance value and the radio frequency reflection coefficient, including:

[0068] The load impedance in the loop of the radio frequency system can be calculated using the following formula: ZL=Z0(1+ρ) / (1-ρ)

[0069] Where ZL represents the load impedance in the loop of the RF system; Z0 represents the characteristic impedance value; and ρ represents the RF reflection coefficient.

[0070] Specifically, the control module calculates the load resistance value of the skin affected by the radio frequency energy based on the calculated phase angle of the voltage and current in the circuit of the radio frequency system and the load impedance in the circuit of the radio frequency system, including:

[0071] The load resistance of the skin subjected to the radiofrequency energy is calculated using the following formula: R = ZL * cosθ

[0072] Where R represents the load resistance value; ZL represents the load impedance in the RF system loop; and θ represents the phase angle of the voltage and current in the RF system loop.

[0073] Specifically, the control module adjusts the duty cycle of the second PWM control module based on the calculated load resistance value, including:

[0074] From the correspondence between load resistance value and RF output power, find the RF output power corresponding to the calculated load resistance value;

[0075] From the correspondence between RF output power and power amplifier module input voltage, the power amplifier module input voltage corresponding to the RF output power is found, wherein the power amplifier module input voltage is the voltage output by the main power supply to the power amplifier module;

[0076] From the correspondence between the input voltage of the power amplifier module and the duty cycle of the second PWM, find the second PWM duty cycle corresponding to the input voltage of the power amplifier module;

[0077] The duty cycle of the second PWM control module is adjusted based on the retrieved second PWM duty cycle.

[0078] Specifically, the second PWM control module adjusts the output voltage of the main power supply according to the adjusted duty cycle, thereby regulating the RF output energy of the RF system, including:

[0079] The second PWM control module adjusts the voltage output from the main power supply to the power amplifier module according to the adjusted duty cycle output by the control module. At the same time, the control module sends a control command to the PWM signal output module to control the working mode of the first PWM control module. The working mode of the first PWM control module includes: a preset duty cycle and frequency.

[0080] The first PWM control module controls the power amplifier module to output radio frequency energy according to the duty cycle and frequency carried in the operating mode, based on the operating mode.

[0081] The power amplification module outputs adjusted radio frequency energy based on the voltage adjusted by the main power supply, according to the duty cycle and the frequency. The output radio frequency energy passes through the first processing module and the radio frequency output terminal and then acts on the skin, thereby completing the adjustment of the radio frequency output energy of the radio frequency system.

[0082] In one embodiment, the preset duty cycle is 80%; the preset frequency is 4 Hz.

[0083] The radio frequency output mode is controlled by a 4Hz 80% duty cycle modulation signal circuit, which can effectively reduce the pain and discomfort experienced by patients during radiofrequency treatment.

[0084] In related technologies, radiofrequency treatment systems lack skin impedance detection functionality. The radiofrequency system proposed in this embodiment, which automatically adjusts output energy based on skin impedance detection, adds a function to detect skin impedance before treatment. Then, it automatically adjusts the radiofrequency energy output by the radiofrequency system based on the detected skin impedance value. This technology can solve the problem of automatically adjusting the amount of radiofrequency energy for different patients and different skin sites during radiofrequency treatment, making patients feel comfortable and adaptable throughout the treatment process, and enhancing patient safety and treatment effectiveness.

[0085] In summary, this embodiment proposes a radio frequency (RF) system that automatically adjusts output energy based on skin impedance detection. The RF signal output from the active crystal oscillator module is amplified by a power amplifier module and processed by a first processing module, resulting in RF energy that acts on the skin. The first processing module sends a detection signal to the RF energy to detect its forward and reverse voltages, feeding these values ​​back to the control module. The control module adjusts the duty cycle of a second PWM control module based on the forward and reverse voltages. The second PWM control module then adjusts the output voltage of the main power supply based on the adjusted duty cycle, thereby adjusting the RF system's output energy. The radio frequency energy output is adjusted. Compared with the method in related technologies where the output of radio frequency systems is mainly adjusted based on the doctor's experience and the patient's feelings, this method can detect the forward and reverse voltages of the radio frequency energy applied to the skin. The control module adjusts the duty cycle of the second PWM control module according to the forward and reverse voltages. The second PWM control module adjusts the output voltage of the main power supply according to the adjusted duty cycle, thereby adjusting the radio frequency energy output by the radio frequency system. This allows for automatic adjustment of the radio frequency energy applied to the skin without manual adjustment, greatly improving the accuracy of the radio frequency energy output by the radio frequency system.

[0086] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A radio frequency system for automatically adjusting output energy based on skin impedance detection, characterized in that, include: The system includes a main power supply, a power conversion and voltage regulation module, a first PWM control module, a second PWM control module, a control module, a PWM signal output module, a power amplifier module, an active crystal oscillator module, a first processing module, a second processing module, and an RF output terminal. The main power supply is connected to the power conversion and voltage regulation module, the first PWM control module, the second PWM control module, and the power amplification module, respectively. The power conversion and voltage regulation module is also connected to the control module. The first PWM control module is also connected to the PWM signal output module and the power amplification module, respectively. The second PWM control module is also connected to the control module. The control module is also connected to the PWM signal output module, the first processing module, and the second processing module. The power amplification module is also connected to the active crystal oscillator module and the first processing module. The first processing module is also connected to the second processing module and the RF output terminal. The radio frequency (RF) signal output by the active crystal oscillator module is amplified by the power amplifier module and processed by the first processing module, and then outputs RF energy at the RF output terminal, which acts on the skin. The first processing module sends a detection signal to the RF energy to detect the forward and reverse voltages of the RF energy, and feeds back the detected forward and reverse voltages to the control module. The control module adjusts the duty cycle of the second PWM control module according to the forward and reverse voltages. The second PWM control module adjusts the output voltage of the main power supply according to the adjusted duty cycle, thereby regulating the RF energy output by the RF system.

2. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 1, characterized in that, The control module adjusts the duty cycle of the second PWM control module according to the forward voltage and the reverse voltage, including: The control module calculates the radio frequency reflection coefficient based on the forward voltage and the reverse voltage; Obtain the characteristic impedance value, and calculate the load impedance in the loop of the radio frequency system based on the characteristic impedance value and the radio frequency reflection coefficient; The phase angles of the voltage and current in the loop of the radio frequency system are calculated; Based on the calculated phase angle of the voltage and current in the circuit of the radio frequency system and the load impedance in the circuit of the radio frequency system, the load resistance value of the skin subjected to the radio frequency energy is calculated. The duty cycle of the second PWM control module is adjusted based on the calculated load resistance value.

3. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 2, characterized in that, The first processing module is specifically used for: Detect voltage and current signals in the circuit of the radio frequency system; By comparing the phase of the voltage signal and the phase of the current signal, the phase difference between the phase of the voltage signal and the phase of the current signal is obtained; The second processing module is specifically used for: The phase difference is converted into an analog voltage signal, and the analog voltage signal is sent to the control module; The control module calculates the phase angle of the voltage and current in the loop of the radio frequency system, including: Obtain the reference voltage; The phase angle of voltage and current in the RF system loop can be calculated using the following formula: θ=V AD2 *4π / Vm Where θ represents the phase angle of the voltage and current in the loop of the radio frequency system; V AD2 Vm represents the analog voltage signal; Vm represents the reference voltage.

4. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 2, characterized in that, The first processing module is further specifically used for: Detect the forward and reverse voltages in the circuit of the radio frequency system; The detected positive and reverse voltages in the circuit of the radio frequency system are sent to the control module; The control module calculates the radio frequency reflection coefficient based on the forward voltage and the reverse voltage, including: The VSWR in the loop of the radio frequency system is calculated using the following formula: SWR=(AD1 FWD +AD1 REF ) / (AD1 FWD -AD1 REF ) Wherein, SWR represents the standing wave ratio in the RF system loop; AD1 FWD Indicates forward voltage; AD1 REF Indicates reverse voltage; The radio frequency reflection coefficient is calculated using the following formula: ρ=(SWR-1) / (SWR+1) Where ρ represents the radio frequency reflection coefficient.

5. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 2, characterized in that, The control module calculates the load impedance in the loop of the radio frequency system based on the characteristic impedance value and the radio frequency reflection coefficient, including: The load impedance in the loop of the radio frequency system is calculated using the following formula: ZL=Z0(1+ρ) / (1-ρ) Where ZL represents the load impedance in the loop of the RF system; Z0 represents the characteristic impedance value; and ρ represents the RF reflection coefficient.

6. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 2, characterized in that, The control module calculates the load resistance value of the skin affected by the radio frequency energy based on the calculated phase angle of the voltage and current in the circuit of the radio frequency system and the load impedance in the circuit of the radio frequency system, including: The load resistance value of the skin affected by the radio frequency energy is calculated using the following formula: R = ZL * cosθ Where R represents the load resistance value; ZL represents the load impedance in the RF system loop; and θ represents the phase angle of the voltage and current in the RF system loop.

7. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 2, characterized in that, The control module adjusts the duty cycle of the second PWM control module based on the calculated load resistance value, including: From the correspondence between load resistance value and RF output power, find the RF output power corresponding to the calculated load resistance value; From the correspondence between RF output power and power amplifier module input voltage, the power amplifier module input voltage corresponding to the RF output power is found, wherein the power amplifier module input voltage is the voltage output by the main power supply to the power amplifier module; From the correspondence between the input voltage of the power amplifier module and the duty cycle of the second PWM, find the second PWM duty cycle corresponding to the input voltage of the power amplifier module; The duty cycle of the second PWM control module is adjusted based on the retrieved second PWM duty cycle.

8. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 1, characterized in that, The second PWM control module adjusts the output voltage of the main power supply according to the adjusted duty cycle, thereby regulating the RF output energy of the RF system, including: The second PWM control module adjusts the voltage output from the main power supply to the power amplifier module according to the adjusted duty cycle output by the control module. At the same time, the control module sends a control command to the PWM signal output module to control the working mode of the first PWM control module. The working mode of the first PWM control module includes: a preset duty cycle and frequency. The first PWM control module controls the power amplifier module to output radio frequency energy according to the duty cycle and frequency carried in the operating mode, based on the operating mode. The power amplification module outputs adjusted radio frequency energy based on the voltage adjusted by the main power supply, according to the duty cycle and the frequency. The output radio frequency energy passes through the first processing module and the radio frequency output terminal and then acts on the skin, thereby completing the adjustment of the radio frequency output energy of the radio frequency system.

9. The radio frequency system for automatically adjusting output energy based on skin impedance detection according to claim 8, characterized in that, The preset duty cycle is 80%; the preset frequency is 4 Hz.

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