Impedance detection control method and high-frequency skin treatment equipment

Abstract

The invention provides an impedance detection control method and high-frequency skin treatment equipment, the high-frequency skin treatment equipment comprises a high-frequency power supply, a controller connected with the high-frequency power supply and at least one electrode electrically connected with the high-frequency power supply, and the high-frequency power supply is used for applying periodic high-frequency voltage pulses to the electrodes; the impedance detection control method comprises the following steps: acquiring a plurality of output voltage values at a preset acquisition frequency in an output time domain of a high-frequency voltage pulse; performing filtering processing on the plurality of output voltage values to obtain an output voltage filtering value; if the output voltage filtering value is larger than the preset voltage threshold value, the controller detects the impedance of the skin based on the current output voltage value. According to the invention, the sampling action is strictly limited in the output time domain of the high-frequency voltage pulse so as to avoid crosstalk signals in a non-output time period and improve the accuracy of voltage sampling; secondly, filtering processing is carried out on the collected multiple voltage values to suppress instantaneous noise, and finally skin impedance detection is executed when output is stable and effective, so that the accuracy of impedance detection is improved.

Description

Technical Field

[0001] This invention relates to the field of impedance detection technology, and in particular to an impedance detection control method and a high-frequency skin treatment device. Background Technology

[0002] The electrode assembly is a novel cosmetic component with multiple electrodes; each electrode is connected to a high-frequency output channel that independently outputs a high-frequency signal. Load impedance testing of each high-frequency channel can be used to determine if the high-frequency channel is functioning correctly and to provide a basis for impedance matching of the high-frequency channels.

[0003] However, in application scenarios, multiple electrodes of the electrode assembly are attached to the face. Since each high-frequency output channel outputs high-frequency signals independently, and the high-frequency energy output time of each channel is independently controlled, various output combinations will exist. Existing technology uses continuous sampling of each high-frequency output channel, but this method has the following problems: when any one of the multiple high-frequency output channels outputs, it will receive signals from other channels that are not outputting or are currently outputting (such as RF or EMS signals), resulting in electromagnetic coupling. Through parasitic capacitance and mutual inductance, interference voltage is generated in adjacent lines, forming a voltage difference. This will cause current to flow from the high potential circuit to the low potential circuit, resulting in external current crosstalk in the low potential output circuit, which will affect the accuracy of impedance detection and forward and reverse voltage sampling. Summary of the Invention

[0004] The main objective of this invention is to provide an impedance detection control method and a high-frequency skin treatment device, which aim to improve the accuracy of impedance detection and voltage sampling.

[0005] To achieve the above objectives, the present invention proposes an impedance detection and control method, which is applied to a high-frequency skin treatment device. The high-frequency skin treatment device includes a high-frequency power supply, a controller connected to the high-frequency power supply, and at least one electrode electrically connected to the high-frequency power supply. The high-frequency power supply is used to apply periodic high-frequency voltage pulses to the electrode. The impedance detection and control method includes: In the output time domain of the high-frequency voltage pulse, multiple output voltage values ​​are acquired at a preset acquisition frequency; Multiple output voltage values ​​are filtered to obtain the filtered output voltage value; If the output voltage filter value is greater than the preset voltage threshold, the controller detects the skin impedance based on the current output voltage value.

[0006] Optionally, if the output voltage filter value is less than or equal to a preset voltage threshold, the step of acquiring multiple output voltage values ​​at a preset acquisition frequency in the output time domain of the high-frequency voltage pulse is repeated.

[0007] Optionally, multiple output voltage values ​​are filtered to obtain filtered output voltage values, including: The output voltage filter value is obtained by averaging the multiple output voltage values ​​after removing the maximum and minimum values ​​at least once.

[0008] Optionally, multiple output voltage values ​​are acquired at a preset acquisition frequency during the rising time domain of the high-frequency voltage pulse output.

[0009] Optionally, the preset sampling frequency has a range of 10MHz-100MHz.

[0010] Optionally, the high-frequency device also includes an impedance detection circuit, wherein the controller detects the skin's impedance based on the current output voltage value, including: Set the current output voltage to a positive voltage; The controller controls the impedance detection circuit to acquire the reverse voltage corresponding to the forward voltage, and calculates the impedance value and / or the ratio of the forward voltage to the reverse voltage.

[0011] Optionally, the controller detects the skin's impedance based on the current output voltage value, and then further includes: If the output voltage filter value is less than or equal to the preset voltage threshold, the controller sets the calculated impedance value and the ratio of forward voltage to reverse voltage to the default value.

[0012] The present invention also proposes a high-frequency skin treatment device, which includes a high-frequency power supply, a controller connected to the high-frequency power supply, and at least one electrode electrically connected to the high-frequency power supply. A high-frequency power supply for applying periodic high-frequency voltage pulses to at least one electrode; The controller is used to execute the impedance detection control method.

[0013] Optionally, at least one electrode includes at least a plurality of electrodes having a bipolar mode; The controller is used to control the high-frequency power supply to apply periodic high-frequency voltage pulses to two of the multiple electrodes at a given moment, with each electrode being positive and the other negative.

[0014] Optionally, at least one electrode includes multiple electrodes having at least a single-stage mode; The controller is used to control the high-frequency power supply to apply periodic high-frequency voltage pulses to multiple electrodes simultaneously or sequentially.

[0015] This invention proposes an impedance detection control method and a high-frequency skin treatment device. The impedance detection control method is applied to the high-frequency skin treatment device, which includes a high-frequency power supply, a controller connected to the high-frequency power supply, and at least one electrode electrically connected to the high-frequency power supply. The high-frequency power supply is used to apply periodic high-frequency voltage pulses to the electrode. The impedance detection control method includes: acquiring multiple output voltage values ​​at a preset acquisition frequency in the output time domain of the high-frequency voltage pulse; filtering the multiple output voltage values ​​to obtain a filtered output voltage value; if the filtered output voltage value is greater than a preset voltage threshold, the controller detects the skin impedance based on the current output voltage value. This invention first strictly limits the sampling action to the output time domain of the high-frequency voltage pulse to avoid crosstalk signals during non-output periods and improve the accuracy of voltage sampling; secondly, it filters the acquired multiple voltage values ​​to suppress transient noise; and finally, it performs skin impedance detection when the pulse output voltage is stable and effective, thereby improving the accuracy of impedance detection. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of multi-path interference. Figure 2 This is a schematic diagram of the steps in the first embodiment of the impedance detection and control method of the present invention.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention 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 the present invention, and not all of the 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.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0023] like Figure 1 As shown, when any one of the multiple high-frequency output channels outputs, it will cause electromagnetic coupling to the other channels that do not output high-frequency signals. Through parasitic capacitance and mutual inductance, interference voltage is generated in adjacent lines, forming a voltage difference. As a result, current will flow from the high potential circuit to the low potential circuit, causing external current crosstalk in the low potential output circuit. Figure 1 Let's take three RF output channels in output mode as an example. The diagram shows the first RF output channel outputting a voltage RF signal, while the second and third RF output channels are not outputting RF signals. It's easy to understand that at this time, all three RF output channels are in output mode, but because the timing and waveform of their respective output RF signals are different, the RF signal from the first RF output channel generates interference voltage in the second and third RF output channels through electromagnetic coupling. Even though the second and third RF output channels are not outputting signals at this moment, the presence of interference voltage will cause their positive output voltages to increase.

[0024] The impedance detection and control method proposed in this invention is applied to a high-frequency skin treatment device. The high-frequency skin treatment device includes a high-frequency power supply, a controller connected to the high-frequency power supply, and at least one electrode electrically connected to the high-frequency power supply. The high-frequency power supply is used to apply periodic high-frequency voltage pulses to the electrode.

[0025] High-frequency voltage pulses travel through electrodes to the user's skin in contact with the electrodes. The high-frequency power supply is also connected to a controller.

[0026] In the first embodiment, as Figure 2 As shown, the impedance detection control method includes: Step S10: In the output time domain of the high-frequency voltage pulse, acquire multiple output voltage values ​​at a preset acquisition frequency.

[0027] In one example of this invention, the high-frequency voltage pulse is provided by a high-frequency power supply. It is readily understood that in this example, the invention divides one cycle of the high-frequency voltage pulse into an "output time domain" and a "non-output time domain." The output time domain typically corresponds to the period when the pulse signal is at a high level and energy is actually transferred to the load (skin); while the non-output time domain includes periods of low level, dead time, or other channel operation. The core of this step is to strictly limit the sampling action to the "output time domain." The preset sampling frequency is determined by the researchers and is not limited in this invention.

[0028] In one example of this invention, the controller accurately determines whether a certain electrode circuit has entered the output time domain by monitoring the enable signal or pulse modulation signal of the high-frequency power supply. Upon confirmation of entry into the output time domain, the controller immediately activates the analog-to-digital converter corresponding to that circuit to continuously sample the output voltage on the circuit's electrode at a relatively high preset sampling frequency (e.g., 10MHz to 100MHz), acquiring a set of continuous raw output voltage data. It is easy to understand that limiting the sampling time to the output time domain of its own circuit fundamentally avoids crosstalk caused by other circuits during operation, because the controller does not sample the circuit when it is not outputting, thus isolating interference in the time dimension.

[0029] It is easy to understand that, compared to the existing technology that performs uninterrupted continuous sampling, which causes crosstalk from the electrodes in the output state to affect the sampling accuracy of the electrodes not in the output state, this embodiment only samples the electrodes in the output state. This avoids using the sampled voltage values ​​of the electrodes not in the output state, eliminates the influence of the interfered sampled voltage values ​​on subsequent calculations, improves the accuracy of voltage sampling, and also reduces the power consumption of the device compared to the uninterrupted continuous sampling method.

[0030] Step S20: Filter the multiple output voltage values ​​to obtain the filtered output voltage value.

[0031] Although most external crosstalk has been avoided through the timing of sampling, the sampled data may still contain transient interference caused by circuit thermal noise, switching noise, or slight coupling. This interference usually manifests as abnormally high or low values ​​in the sampling sequence. Directly using this raw data will still affect the accuracy of subsequent judgments.

[0032] In this step, the output voltage value can refer only to the forward output voltage, which is filtered to obtain the filtered output voltage value. Alternatively, the output voltage value can include both the forward and reverse output voltages.

[0033] This embodiment, taking into account the characteristics of external interference or instability, can filter the sampled forward and / or reverse output voltage data separately to obtain filtered output voltage values ​​and reverse filtered voltage values. The filtered output voltage values ​​are then compared with a preset voltage threshold.

[0034] It's easy to understand that filtering the sampled forward and reverse output voltage data separately can remove noise signals caused by external interference, thus purifying the forward and reverse output voltage data. Calculating the load impedance value based on the filtered output voltage value and the filtered reverse voltage value can improve the accuracy of the obtained load impedance value.

[0035] This embodiment does not limit the specific filtering method for filtering the forward and reverse output voltage data.

[0036] In one example, the filtered output voltage value can be obtained by performing a multi-window sliding filter on the output voltage data.

[0037] Specifically, in the output time domain of the high-frequency voltage pulse (taking the forward output voltage as an example), N source data are continuously sampled starting at a preset sampling frequency. These N source data are then used for the first window sliding filter. The filter first removes the maximum and minimum values, then takes the average, and outputs a relatively stable data to the sliding filter source data. A second window sliding filter is then performed using M source data after the first window sliding filter. This process continues until multiple window sliding filters are completed, resulting in the corresponding output voltage filter value and reverse filter voltage value. This example uses a dual-window sliding filter. It should be noted that this example does not limit the number of window sliding filters performed; the specific number of multiple window sliding filters can be determined by the developers. It should also be explained that a window is a way for software algorithms to process data. For example, a data linked list can store 10 data items. When a new data item is sampled and needs to be stored in the list, the last data item in the list is discarded, the remaining 9 data items are moved one cache address to the right, and the new data item is placed at the head of the freed-up list. A voltage data point is determined based on the updated linked list and used as the input data for the next window filter, until the final window filter yields the output voltage filter value or the reverse filtered voltage value.

[0038] In another example, the filtered output voltage value can be obtained by performing median averaging on the output voltage data.

[0039] In this example, the sampled output voltage data (values) are first sorted, extreme values ​​are removed, and the average value is calculated. First, the sampled output voltage values ​​are sorted in ascending (or descending) order. Then, the maximum and minimum values ​​are removed from the sorted data (if there are many sampled output voltage values, a set number of maximum and minimum values ​​can be removed sequentially; this set number is determined by the R&D personnel). Finally, the arithmetic mean of the remaining output voltage values ​​is calculated as the final output of this filtering process. Additionally, it should be noted that for real-time continuous filtering, the data window is moved one position to the right: the oldest data point is discarded, the most recently acquired data point is added, and then the sorting, extreme value removal, and average calculation are performed.

[0040] Step S30: If the output voltage filter value is greater than the preset voltage threshold, the controller detects the skin impedance based on the current output voltage value.

[0041] After filtering, we obtain a relatively stable output voltage characteristic value (i.e., the filtered output voltage value). However, in some cases, such as when the output power is extremely low, or when the output is just beginning / about to end, the filtered voltage value may still be low. To further ensure that impedance detection is performed under the premise that the output is sufficiently stable and effective, this invention introduces a voltage threshold judgment mechanism.

[0042] In one example of the invention, a "preset voltage threshold" is pre-stored within the device. This threshold is an empirical or calibrated value that is slightly higher than the interference voltage level that may be caused by residual coupling or noise, but much lower than the output voltage during normal operation. The controller output voltage filter value is compared with this preset voltage threshold.

[0043] If the comparison result shows that the output voltage filter value is greater than the preset voltage threshold, the controller determines that the current electrode circuit is in a valid and stable output state. At this time, the controller uses the currently acquired output voltage value (or output voltage filter value) as valid data and starts or continues to execute the skin impedance detection process. Impedance detection may include: acquiring the corresponding reverse reflected voltage, and calculating the voltage standing wave ratio (VSWR) and / or load impedance value based on the forward and reverse voltages.

[0044] Conversely, if the output voltage filter value is less than or equal to the preset voltage threshold, the controller determines that the current output is invalid or unstable. In this case, the controller can abandon the current sampling loop and return to the step "in the output time domain of the high-frequency voltage pulse, collect multiple output voltage values ​​at a preset sampling frequency" to wait for resampling in the next output time domain, or output a preset default impedance value to avoid using erroneous data for energy control.

[0045] This invention does not limit the specific filtering algorithm; in addition to extreme value averaging filtering, other digital filtering algorithms such as moving average filtering and median filtering can also be used. The preset voltage threshold can also be dynamically adjusted according to different output levels of the device to enhance adaptability.

[0046] Accordingly, in one example, if the output voltage filter value is less than or equal to a preset voltage threshold, the step of acquiring multiple output voltage values ​​at a preset acquisition frequency in the output time domain of the high-frequency voltage pulse is repeated.

[0047] It's easy to understand that when the output voltage filter value is less than or equal to the preset voltage threshold, it indicates that the high-frequency voltage pulse is not stable or effective enough, possibly at a stage of extremely low output power or just beginning / about to end. In this case, directly calculating the impedance based on this invalid or low-reliability data will inevitably introduce errors. By comparing the output voltage filter value with the preset voltage threshold, corresponding measures can be taken to tolerate occasional instability that may occur within a single sampling or pulse cycle. Through continuous monitoring and retries, stable and effective output moments can be dynamically captured. Furthermore, this significantly reduces the risk of the entire detection process being interrupted or producing incorrect results due to accidental failures in a single sampling, thereby greatly improving the final success rate and reliability of the impedance detection process.

[0048] In one embodiment of the present invention, after determining that the output voltage filter value is substandard, the controller will immediately or after a very short delay re-enable the sampling circuit and, in the subsequent output time domain within the current pulse cycle or the output time domain of the next pulse cycle, again acquire a new set of output voltage values ​​at a preset acquisition frequency. This process can be repeated until the output voltage filter value obtained after a certain acquisition and filtering successfully exceeds a preset voltage threshold, at which point the system will proceed to the subsequent impedance detection process. Optionally, to prevent infinite loops in unexpected situations, a maximum number of retries or a timeout mechanism can be set.

[0049] This invention proposes an impedance detection control method and a high-frequency skin treatment device. The impedance detection control method is applied to the high-frequency skin treatment device, which includes a high-frequency power supply, a controller connected to the high-frequency power supply, and at least one electrode electrically connected to the high-frequency power supply. The high-frequency power supply is used to apply periodic high-frequency voltage pulses to the electrode. The impedance detection control method includes: acquiring multiple output voltage values ​​at a preset acquisition frequency in the output time domain of the high-frequency voltage pulse; filtering the multiple output voltage values ​​to obtain a filtered output voltage value; if the filtered output voltage value is greater than a preset voltage threshold, the controller detects the skin impedance based on the current output voltage value. This invention first strictly limits the sampling action to the output time domain of the high-frequency voltage pulse to avoid crosstalk signals during non-output periods and improve the accuracy of voltage sampling; secondly, it filters the acquired multiple voltage values ​​(e.g., by removing extreme values ​​and averaging) to suppress transient noise; and finally, it performs skin impedance detection when the output is stable and effective, thereby improving the accuracy of impedance detection.

[0050] In one example, multiple output voltage values ​​are filtered to obtain filtered output voltage values, including: The output voltage filter value is obtained by averaging the multiple output voltage values ​​after removing the maximum and minimum values ​​at least once.

[0051] It should be noted that after the controller acquires a set of continuous raw output voltage values ​​in the output time domain, it needs to filter them to improve data quality.

[0052] In high-frequency skin treatment equipment, the interference to the sampled data mainly falls into two categories: one is continuous, low-amplitude background noise (such as thermal noise); the other is occasional, high-amplitude pulse interference (such as switching noise, instantaneous strong electromagnetic coupling). Simple arithmetic mean filtering will weight all data points equally, leading to a few extremely high pulse interferences that severely distort the average value.

[0053] This example adds a simple "data validity screening" step before averaging, first removing outlier data points that deviate significantly from the normal range (i.e., the maximum and minimum values), and then averaging the remaining representative data.

[0054] It should be noted that "at least once" means that this extreme value removal averaging operation can be performed multiple times. For example, in another embodiment, the remaining 14 data points can be processed again to remove one maximum and one minimum value, and then the remaining 12 data points can be averaged to form a two-stage extreme value removal averaging filter to cope with more complex interference environments.

[0055] In one example, multiple output voltage values ​​are acquired at a preset acquisition frequency during the rising time domain of the high-frequency voltage pulse output.

[0056] It's important to clarify that the "output rise time domain" specifically refers to the period from when a high-frequency voltage pulse starts rising from a low level (or zero level) towards a set target level until it reaches a relatively stable state. This time period is chosen based on a thorough consideration of the circuit's dynamic characteristics and the quality of the sampled data. While valid output may exist throughout the entire "output time domain," the initial rise phase of the pulse has unique value. Waiting for the voltage to fully stabilize before sampling will yield the smoothest data, but it will significantly shorten the effective data window for continuous acquisition, especially with high-frequency pulses with short duty cycles, potentially resulting in insufficient sampling points for subsequent filtering. Conversely, sampling at the very beginning of the pulse (i.e., the start of the rising edge) may result in extremely low voltage data, almost entirely noise.

[0057] In practice, the controller can identify and enter the "rising time domain" in several ways. In one embodiment, after detecting a high-frequency power supply output enable signal, the controller does not immediately initiate sampling but waits for a very short fixed delay (e.g., tens to hundreds of nanoseconds). This delay corresponds to the moment when the voltage begins to rise and reaches a recognizable low threshold (e.g., 10% of the target voltage). Subsequently, the controller activates a high-speed analog-to-digital converter for continuous sampling. In another embodiment, the controller can monitor the output of a fast comparator in real time. This comparator compares the output voltage with a lower reference threshold, and determines that it has entered the rising time domain and triggers sampling when its output changes.

[0058] In one example, the preset sampling frequency has a range of 10MHz-100MHz.

[0059] It's important to explain that the rise time of high-frequency voltage pulses (such as radio frequency pulses) is typically extremely short, ranging from tens of nanoseconds to microseconds. According to the Nyquist sampling theorem, to accurately reproduce the details of a signal without distortion, the sampling frequency needs to be at least twice that of the highest frequency component of the signal. Radio frequency beauty devices typically operate at frequencies between hundreds of kHz and several MHz. Setting the sampling frequency much higher (starting from 10MHz) ensures sufficient sampling of the fundamental signal while also covering higher harmonic components that may be caused by switching actions, avoiding frequency aliasing interference due to undersampling, and guaranteeing the spectral purity of the sampled data. Although we are ultimately concerned with the voltage amplitude (low-frequency information), extremely high time resolution is required to accurately depict the voltage's trajectory from low to high within the brief rise time domain and to accurately capture the start and slope of the rising edge. The sampling period is 100 nanoseconds for 10MHz and 10 nanoseconds for 100MHz. This ensures that even in a very short rise time, enough sampling points can be obtained (for example, 20 data points can be obtained for a 200 nanosecond rise time at a 100MHz sampling rate), thus providing rich dynamic information for subsequent judgment of the output state.

[0060] Furthermore, it's important to clarify that the upper limit of the sampling frequency (100MHz) is constrained by the controller's processing power, analog-to-digital converter performance, data bus bandwidth, and system power consumption. Excessively high sampling rates generate massive amounts of data, placing enormous pressure on real-time filtering and computation. The 10MHz-100MHz range represents the optimal range within the real-time processing capabilities of current mainstream embedded processors (such as high-performance MCUs or FPGAs), offering both sufficient accuracy and engineering feasibility.

[0061] In the second embodiment, the high-frequency device further includes an impedance detection circuit, wherein the controller detects the skin's impedance based on the current output voltage value, including: Set the current output voltage to a positive voltage; The controller controls the impedance detection circuit to acquire the reverse voltage corresponding to the forward voltage, and calculates the impedance value and / or the ratio of the forward voltage to the reverse voltage.

[0062] It should be noted that the current output voltage can be the filtered output voltage value after filtering in step S20 and determined by the threshold in step S30, or it can be the latest or most representative original voltage value directly read by the controller from the sampling circuit, provided that the filtered value is valid. Setting it as a "positive voltage" means that the controller internally identifies this value as the incident voltage (V+) transmitted from the high-frequency power supply towards the skin load in its internal logic or data storage. Next, the controller controls the impedance detection circuit to acquire the reverse voltage corresponding to the positive voltage. The impedance detection circuit is a key hardware submodule in the system of this invention. In a typical embodiment, this circuit includes a directional coupler and an analog-to-digital converter module. The directional coupler is connected in series in the RF output channel, and its characteristic is that it can non-invasively and directionally couple the positive wave (incident wave) and the reverse wave (reflected wave) on the transmission line. When the controller determines that impedance needs to be detected, it sends a command to the circuit to start sampling at the reverse coupling port. The analog-to-digital converter module converts the coupled analog reverse voltage signal into a digital quantity, i.e., the reverse voltage value (V-), and provides it to the controller. This process enables the physical capture of the load-reflected signal.

[0063] After simultaneously acquiring a valid forward voltage value (V+) and the corresponding reverse voltage value (V-), the controller performs calculations. Specifically, this may include: Reflectance coefficient ,in, This is the reverse voltage value. This is the positive voltage value.

[0064] Voltage standing wave ratio (VSWR, denoted as S) is a core indicator for measuring the "impedance matching degree" of a high-frequency system, reflecting the strength of standing waves on the transmission line (S≥1, S=1 indicates perfect matching with no standing waves).

[0065] VSWR and reflection coefficient amplitude Directly related, the derivation logic is as follows: Maximum voltage on the transmission line minimum voltage VSWR is defined as "the ratio of the maximum voltage to the minimum voltage", that is: Combined with the amplitude of the reflection coefficient (Since the voltage amplitude is non-negative, it can be simplified to) Substituting into the above formula, we get: .

[0066] According to transmission line theory, the reflection coefficient... With load impedance Characteristic impedance The relationship is: .

[0067] In addition, it is important to note that if there is a phase difference between the forward voltage and the reverse filter voltage, the load impedance needs to be calculated by combining the phase difference between the two, the amplitude of the forward filter voltage, and the amplitude of the reverse filter voltage.

[0068] In one example, the controller detects the skin's impedance based on the current output voltage value, and then includes: If the output voltage filter value is less than or equal to the preset voltage threshold, the controller sets the calculated impedance value and the ratio of forward voltage to reverse voltage to the default value.

[0069] It should be noted that in the closed-loop control of high-frequency skin treatment equipment, the host computer typically needs to periodically receive impedance detection data from the slave computer (i.e., the controller of this invention) to determine the treatment status and decide whether to continue, adjust, or stop the energy output. If a single invalid detection results in data frame loss or abnormal output values ​​(such as NaN, maximum, or minimum values), it may cause misjudgment by the host computer, leading to unexpected treatment interruption or the generation of unsafe control commands. By outputting a set of predefined, safe "setpoints" (e.g., voltage standing wave ratio set to 1.1, load impedance set to a typical neutral value such as 50Ω), the continuity of the data stream is ensured. These setpoints are usually interpreted by the host computer as "the device is performing a normal self-test, but the current output does not meet the detection conditions," thereby triggering a safe wait or retry logic, rather than an emergency shutdown.

[0070] Furthermore, combining the original data stored in an invalid state with the output setpoints can create a silent fault recording mechanism. This allows the system to record on-site data when an abnormal event occurs without interfering with current operation. Maintenance personnel or self-diagnostic programs can access this data to analyze whether it is intermittent interference, an output circuit fault, or a load (skin contact) abnormality, thereby achieving accurate differentiation and location of different problems.

[0071] The present invention also proposes a high-frequency skin treatment device, which includes a high-frequency power supply, a controller connected to the high-frequency power supply, and at least one electrode electrically connected to the high-frequency power supply. A high-frequency power supply for applying periodic high-frequency voltage pulses to at least one electrode; The controller is used to execute the impedance detection control method.

[0072] It's important to explain that the electrode is the terminal interface for energy transfer and signal acquisition. It comes into direct contact with the skin via an electrical connection. On one hand, it applies voltage pulses generated by a high-frequency power supply to the skin tissue; on the other hand, the voltage signal on its surface is sampled as the "output voltage" for subsequent impedance detection. Electrodes can take the form of metal patches, rollers, dot matrix probes, etc. The device can be configured with a single electrode (operating in conjunction with a common ground electrode) or multiple electrodes. The core function of the high-frequency power supply is to generate and apply periodic high-frequency voltage pulses to the load. These pulses are typically AC signals in the radio frequency range (e.g., frequencies between 300 kHz and 10 MHz), used to generate a thermal effect on the skin tissue for cosmetic or therapeutic purposes. The high-frequency power supply can be a standalone radio frequency signal generator module or a power output unit integrated within the controller. Its output parameters (such as frequency, amplitude, duty cycle, and pulse train mode) are precisely controlled by the controller.

[0073] The controller can consist of one or more microprocessors, microcontrollers (MCUs), digital signal processors (DSPs), or field-programmable gate arrays (FPGAs) and their peripheral circuitry. Internally, it contains program instructions that execute the aforementioned methods. It is responsible not only for performing logical judgments, filtering calculations, and threshold comparisons, but also for providing real-time feedback control of the high-frequency power supply output based on the calculation results to adjust the energy output and ensure safety and effectiveness.

[0074] As is easily understood, the controller extracts accurate skin impedance information from the output of the electrode circuit. Based on this information, the controller can determine whether the skin contact is good, whether the energy is effectively absorbed, and whether there are any abnormalities (such as excessively high impedance, which may indicate a risk of overheating). Accordingly, it dynamically adjusts the output parameters of the high-frequency power supply (such as reducing power or stopping output) to achieve intelligent and safe treatment.

[0075] In one example, at least one electrode comprises at least a plurality of electrodes having a bipolar mode; The controller is used to control the high-frequency power supply to apply periodic high-frequency voltage pulses to two of the multiple electrodes at a given moment, with each electrode being positive and the other negative.

[0076] It should be explained that at least a bipolar mode is available, including bipolar, unipolar, and hybrid bipolar output modes. In bipolar mode, the current loop is not formed through a common, large-area return electrode (as in unipolar mode), but rather directly between two adjacent or paired treatment electrodes. Specifically, at a given moment, the controller selects a pair of electrodes (e.g., electrode A and electrode B) and controls the high-frequency power supply to make the potential of electrode A "positive" and the potential of electrode B "negative" (i.e., relative to "ground" or negative phase). In this way, high-frequency current flows from electrode A into the skin tissue, through the subcutaneous target tissue between electrodes A and B, and then back to the device from electrode B, forming a localized, directional closed loop. In this mode, the electric field and current density are highly concentrated in the area between the two electrodes.

[0077] The controller can selectively activate specific electrode pairs via an electrode matrix switching network or a multi-channel output driver. When an electrode pair needs to be activated, the controller configures a switch to connect the positive output of the high-frequency power supply to electrode A, while simultaneously connecting the negative output (or an output with a 180-degree phase reversal) to electrode B. Other unused electrodes are placed in a high-impedance state or a safe ground state. To treat a larger area or achieve uniform energy distribution, the controller can dynamically rotate the activation of different electrode pairs according to a preset timing sequence. For example, it might activate (electrode 1, electrode 2) in the first pulse cycle, and (electrode 2, electrode 3) in the next cycle, and so on.

[0078] In one example, at least one electrode comprises multiple electrodes having at least a single-level mode; The controller is used to control the high-frequency power supply to apply periodic high-frequency voltage pulses to multiple electrodes simultaneously or sequentially.

[0079] It should be explained that at least a single-stage mode is available, including a monopolar mode, or a mode with mixed monopolar and bipolar output. In monopolar mode, the device is equipped with multiple independent treatment electrodes (or "active electrodes") and a common return electrode (usually larger in area, possibly located in the device handle, another body part, or integrated into a non-treatment area of ​​the multipolar mask). When the high-frequency power supply is operating, each treatment electrode is subjected to a high-frequency voltage relative to this common return electrode. Therefore, the current loop flows from one treatment electrode into the skin, through the subcutaneous tissue, and finally converges at the common return electrode back to the device. Each treatment electrode forms a relatively independent treatment channel with respect to the common electrode, and its electric field distribution diffuses outward from the center of that electrode.

[0080] The controller can control the high-frequency power supply to apply high-frequency voltage pulses with the same or different parameters to all selected treatment electrodes within the same time period. This requires the high-frequency power supply to have the ability to output multiple independent channels, or to achieve a "quasi-synchronous" effect by rapidly cycling power supply through a multiplexer switch. This method has high treatment efficiency and is suitable for scenarios requiring large-area synchronous treatment.

[0081] Alternatively, the controller can control a high-frequency power supply to apply high-frequency voltage pulses to each treatment electrode in turn, according to a preset sequence and time interval. At any given time, typically only one (or a group of) electrodes is active. This method has relatively simple power supply requirements and can completely avoid direct electrical interference between the output signals of multiple treatment electrodes through time-division multiplexing.

[0082] The specific steps of the impedance detection and control method are as described in the above embodiments. Since this high-frequency skin treatment device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be repeated here. The above are only optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An impedance detection control method characterized by comprising: The impedance detection control method is applied to a high-frequency skin treatment device, which comprises a high-frequency power supply, a controller connected with the high-frequency power supply, and at least one electrode electrically connected with the high-frequency power supply, and the high-frequency power supply is used to apply periodic high-frequency voltage pulses to the electrode; The impedance detection control method comprises: In the output time domain of the high-frequency voltage pulse, a plurality of output voltage values are collected at a preset collection frequency; The plurality of output voltage values are filtered to obtain an output voltage filtered value; If the output voltage filtered value is greater than a preset voltage threshold, the controller detects the impedance of the skin based on the current output voltage value.

2. The impedance detection control method according to claim 1, wherein If the output voltage filtered value is less than or equal to the preset voltage threshold, the step of collecting a plurality of output voltage values at a preset collection frequency in the output time domain of the high-frequency voltage pulse is repeated.

3. The impedance detection control method according to claim 1, wherein The filtering of the plurality of output voltage values to obtain the output voltage filtered value comprises: At least once, the maximum value and the minimum value of the plurality of output voltage values are removed to obtain the output voltage filtered value.

4. The impedance detection control method according to any one of claims 1 to 3, characterized by, In the output rising time domain of the high-frequency voltage pulse, a plurality of output voltage values are collected at a preset collection frequency.

5. The impedance detection control method according to claim 4, wherein The preset collection frequency has a range of 10MHz-100MHz.

6. The impedance detection control method of claim 1, wherein The high-frequency device further comprises an impedance detection circuit, and the controller detects the impedance of the skin based on the current output voltage value, which comprises: The current output voltage is set as a forward voltage; The controller controls the impedance detection circuit to collect a reverse voltage corresponding to the forward voltage, and calculates an impedance value and / or a ratio of the forward voltage to the reverse voltage.

7. The impedance detection control method according to claim 6, wherein The controller detects the impedance of the skin based on the current output voltage value, and then further comprises: If the output voltage filtered value is less than or equal to the preset voltage threshold, the controller sets the calculated impedance value and the ratio of the forward voltage to the reverse voltage as a default value.

8. A high frequency skin treatment device, characterized in that The high-frequency skin treatment device comprises a high-frequency power supply, a controller connected with the high-frequency power supply, and at least one electrode electrically connected with the high-frequency power supply; The high-frequency power supply is used to apply periodic high-frequency voltage pulses to at least one electrode; The controller is used to execute the impedance detection control method according to any one of claims 1-7.

9. The high frequency skin treatment device in accordance with claim 8, wherein The at least one electrode comprises a plurality of electrodes having at least a bipolar mode; The controller is used to control the high-frequency power supply to apply periodic high-frequency voltage pulses to two electrodes in the plurality of electrodes as positive and negative to each other at a time.

10. The high frequency skin treatment device in accordance with claim 8, wherein The at least one electrode comprises a plurality of electrodes having at least a single-stage mode; The controller is used to control the high-frequency power supply to apply periodic high-frequency voltage pulses to the plurality of electrodes at the same time or in sequence.

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