Transcranial electrical stimulation system and method for reducing skin reactions

Abstract

The present invention discloses a transcranial electrical stimulation system and method for reducing skin reactions, belonging to the field of medical assistive devices. The present invention decomposes a single-electrode stimulation signal into multi-electrode stimulation signal outputs, resulting in a spatial therapeutic field distribution equivalent to that formed by a single-electrode stimulation signal, thereby reducing skin reactions beneath the stimulation electrode. The stimulation parameters of the electrical stimulation are derived from electric field simulations of a head model established using real data. The present invention can be used to reduce skin reactions in patients undergoing transcranial electrical stimulation interventions, thereby improving individual tolerance to the treatment.

Description

Technical Field

[0001] The present invention belongs to the field of medical auxiliary equipment, and in particular relates to a transcranial electrical stimulation system and method for alleviating skin reactions. Background Art

[0002] Transcranial electrical stimulation (TES) is an effective, noninvasive neuromodulation technique that applies weak electrical currents through electrodes to the scalp to stimulate specific brain regions, modulating cortical neural activity or excitability. Currently, TES has been widely used in clinical research for neurological and psychiatric conditions, including stroke rehabilitation and mental disorders, achieving significant clinical results. Exploring its mechanisms of action and optimizing treatment options are hot topics in this field.

[0003] The current view is that TES is relatively safe when the output current is less than 2 mA and the single stimulation time is less than 20 minutes. However, as the clinical application of TES becomes more widespread, reports of adverse reactions in patients are also increasing. Among the adverse reactions reported, the most common are mild itching and tingling at the stimulation site, followed by mild headache and burning sensation. Occasionally, skin damage of varying degrees is seen, such as mild skin burns, subelectrode erythema lasting for several minutes, delayed distal skin lesions, etc., as well as varying degrees of mania and delayed epileptic seizures. The adverse skin reactions are summarized as follows:

[0004] 1) Tingling and itching

[0005] Studies have shown that TES applied to the primary and secondary motor cortex for 20 minutes at a 1mA stimulation current reported a tingling sensation at the electrode contact site and brief flashes of light at the start and end of stimulation. Other studies have shown that TES treatment of schizophrenia patients, with a 2mA current applied for 20 minutes daily, reported tingling in 20% of patients and itching in 40%. Analysis of these adverse reactions revealed that the cause is the sudden localized current accumulation produced by TES. The sudden discharge of the stimulating electrode causes the current to accumulate in a specific area of ​​the electrode, resulting in excessive local current density.

[0006] 2) Skin erythema under the electrode

[0007] Studies have shown that when TES is used to treat patients with depression, the anode is placed on the left dorsolateral prefrontal cortex and the cathode is placed above the right supraorbital area. The stimulation current is divided into two groups, 1mA and 2mA, and each stimulation lasts for 20 minutes. In the 1mA group, all patients had mild redness on the skin below the cathode, which disappeared after a few minutes. There was no redness on the skin below the anode, while the area of ​​skin damage in patients with sensitive skin gradually expanded and the degree of damage gradually deepened. In the 2mA group, the same degree of skin damage was observed below the cathode in all patients, showing widespread redness and brown scabs, and no skin damage was observed below the anode. Analysis of the reasons is related to the appearance of erythema on the skin surface below the cathode and the thermal effect of the current. Stimulation methods that reduce the thermal effect of the current should be used, such as reducing the skin contact impedance or current intensity.

[0008] 3) Skin burns

[0009] When TES is used to treat patients with post-spinal cord injury neuropathic pain, the anode is placed over C3 or C4, and the cathode over the contralateral supraorbital area. A constant current of 2 mA is used for 20 minutes daily. During treatment, some patients experienced adverse events such as skin burns, which occurred under the cathode and were accompanied by small blisters. Analysis revealed that this was due to the incorrect selection of rectangular electrodes, which produce higher peak current concentrations at the electrode corners, leading to excessive local current density and skin damage. Therefore, circular electrodes are more advantageous than square or rectangular electrodes. Compared with circular electrodes, rectangular electrodes produce higher peak current concentrations at the corners.

[0010] 4) Delayed, distal skin lesions

[0011] TES has been used in research to improve cognition. The anode was placed on the left dorsolateral prefrontal cortex, and the cathode was placed on the dorsal left wrist. 20 mL of saline was applied to each electrode, with a current of 1.5 mA for 15 minutes. Results showed that subject 1 experienced visible skin redness after stimulation, and two days later, an itchy, lumpy lesion (approximately 8 mm in diameter) developed on the dorsal wrist at the cathode site. Subject 2 experienced no skin redness after stimulation, but two days later, a non-itchy, non-lumpy lesion (approximately 6 mm in diameter) developed on the volar wrist at the cathode site. Analysis revealed that the cause was inappropriate saline dosing, likely due to saline leakage from the sponge, which formed a conductive pathway through the bandage to the volar wrist. The subject had minor skin injuries, which were not apparent during pre-stimulation skin examination. These minor injuries provided a low-resistance path, concentrating the current across the skin over a smaller area, further exacerbating the injury.

[0012] In order to enhance the tolerance of subjects and improve the patient experience, a transcranial electrical stimulation system and application method that can reduce skin reactions are needed, so as to achieve more comfortable and highly focused individualized neural regulation through more reasonable stimulation targets and parameters. Summary of the Invention

[0013] The present invention aims to address the shortcomings of existing transcranial electrical stimulation technology and provide a transcranial electrical stimulation system and method that can reduce skin reactions. The present invention can reduce adverse skin reactions and improve the subject's tolerance and experience.

[0014] The specific technical solutions adopted in the present invention are as follows:

[0015] In a first aspect, the present invention provides a transcranial electrical stimulation system for alleviating skin reactions, which comprises a control unit and a stimulation parameter solving unit connected to the control unit, an electrical stimulation unit, a stimulation electrode cap, and a power supply unit;

[0016] The stimulation electrode cap is provided with a plurality of stimulation electrodes distributedly arranged therein; the power supply unit is used to supply power to other units;

[0017] The stimulation parameter solving unit is used to read the imaging data of the individual to be intervened, construct an individual head model through brain tissue segmentation and three-dimensional reconstruction, first obtain the spatial treatment field distribution formed by the preset single-electrode stimulation scheme on the head of the individual to be intervened through simulation, then combine the model of the stimulation electrode cap with the individual head model, and obtain the stimulation parameters required for each stimulation electrode in the stimulation electrode cap to equivalently form the spatial treatment field distribution on the head of the individual to be intervened through simulation;

[0018] The electrical stimulation unit has multiple output channels, and the control unit is used to save the stimulation parameters of all stimulation electrodes in the stimulation electrode cap, and control the electrical stimulation unit to output an electrical stimulation waveform capable of alleviating skin reaction to each stimulation electrode in the stimulation electrode cap according to a predefined waveform synthesis strategy;

[0019] In the waveform synthesis strategy, multiple stimulation electrodes at different positions disperse alternate stimulation in the time domain or disperse the original stimulation intensity in terms of stimulation intensity, but the total stimulation duration and the total stimulation intensity at any moment remain consistent with the single-electrode stimulation scheme.

[0020] As a preferred embodiment of the above-mentioned first aspect, in the waveform synthesis strategy, continuous electrical stimulation is performed simultaneously by stimulation electrodes at multiple different positions in the stimulation electrode cap, and the total stimulation duration of each stimulation electrode is consistent with the total stimulation duration in the single-electrode stimulation scheme, and the sum of the stimulation intensities of all stimulation electrodes is consistent with the stimulation intensity in the single-electrode stimulation scheme.

[0021] As a preferred embodiment of the above-mentioned first aspect, in the waveform synthesis strategy, electrical stimulation is performed alternately by stimulation electrodes at multiple different positions in the stimulation electrode cap, and the total duration of the alternating stimulation of all stimulation electrodes is consistent with the total stimulation duration in the single-electrode stimulation scheme, but at a single moment only one stimulation electrode outputs electrical stimulation consistent with the stimulation intensity in the single-electrode stimulation scheme.

[0022] As a preferred embodiment of the above-mentioned first aspect, in the waveform synthesis strategy, electrical stimulation is performed alternately by stimulation electrodes at multiple different positions in the stimulation electrode cap, and the total duration of the alternating stimulation of all stimulation electrodes is consistent with the total stimulation duration in the single-electrode stimulation scheme, but at a single moment, the sum of the stimulation intensities output by at least two stimulation electrodes is the same as the electrical stimulation in the single-electrode stimulation scheme.

[0023] As a preferred embodiment of the above-mentioned first aspect, it also includes a visualization unit, which is used to read the stimulation parameters of each stimulation electrode and the spatial treatment field distribution equivalently formed on the head of the individual to be intervened from the stimulation parameter solution unit, and visualize them according to a preset visualization mode.

[0024] As a preference for the first aspect above, it further includes a communication unit connected to the control unit, for establishing a connection with an external instruction input device and receiving system control instructions input by the external instruction input device.

[0025] As a preference of the above-mentioned first aspect, the system control instruction input by the external instruction input device is a setting instruction for the waveform synthesis strategy or an electrical stimulation treatment parameter.

[0026] As a preferred embodiment of the first aspect, the stimulation electrodes in the stimulation electrode cap 6 are circular electrodes.

[0027] As a preferred embodiment of the above-mentioned first aspect, it also includes an impedance detection unit connected to the control unit, which is used to detect the potential difference between each channel in the electrical stimulation unit and the real-time output current in real time, so as to calculate the equivalent impedance to feedback the electrode detachment situation.

[0028] As a preferred embodiment of the above-mentioned first aspect, it also includes a switching unit connected to the control unit and the electrical stimulation unit. Under the control of the control unit, the switching unit performs switching control on each output channel of the electrical stimulation unit so that the electrical stimulation waveform finally output to each stimulation electrode in the stimulation electrode cap meets the predefined waveform synthesis strategy.

[0029] In a second aspect, the present invention provides a method for optimizing parameters of a transcranial electrical stimulation system for alleviating skin reactions as described in any one of the solutions of the first aspect, comprising:

[0030] S1. Obtain imaging data of the individual to be intervened, perform brain tissue segmentation on the imaging data, and then form an individual head model through three-dimensional reconstruction;

[0031] S2. Determining an original stimulation target and original electrical stimulation parameters according to a preset single-electrode stimulation protocol, constructing a single stimulation electrode at a position corresponding to the original stimulation target on the individual head model, then performing finite element meshing to assign dielectric parameters required for simulation to different tissues and the stimulation electrode; performing finite element simulation of transcranial electrical stimulation according to the original electrical stimulation parameters to obtain a spatial treatment field distribution formed by the single stimulation electrode in the individual head model;

[0032] S3. Assembling the model of the stimulation electrode cap onto the individual head model, re-performing finite element meshing, and assigning dielectric parameters required for simulation to different tissues and the stimulation electrode cap; then searching stimulation parameters for each stimulation electrode in the stimulation electrode cap to find equivalent stimulation parameters that can form the spatial treatment field distribution closest to that of a single stimulation electrode in the individual head model;

[0033] S4. For each waveform synthesis strategy to be selected, finite element simulation is re-performed based on the equivalent stimulation parameters of each stimulation electrode in the stimulation electrode cap. The goal is to make the equivalent spatial treatment field distribution formed during the electrical stimulation treatment process as close as possible to the spatial treatment field distribution formed by a single stimulation electrode. The optimal waveform synthesis strategy is screened out and output as the result together with the equivalent stimulation parameters of each stimulation electrode.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The present invention decomposes a single-ended stimulation signal into multiple groups of stimulation signal outputs, so that the stimulation field potential formed by the decomposition is equivalent to the field potential formed by the single-ended stimulation signal. In combination with a specific stimulation mode, the current density of a single electrode is reduced while ensuring the therapeutic effect, thereby reducing the skin reaction of the subject, improving the individual tolerance of the treatment intervention, and at the same time increasing the continuous service life of the electrode.

[0036] (2) The electrical stimulation sites of the system of the present invention are obtained by simulating the electric field of the head model established by real data, which is conducive to promoting the customization of individualized treatment plans and making the treatment more reasonable and effective. At the same time, under the premise of ensuring the conservation of the treatment energy field, the waveform synthesis strategy, the stimulation current and other parameters can be adjusted in real time to minimize skin damage.

[0037] (3) The electrical stimulation electrodes of the present invention can use circular electrodes to avoid the higher current peak concentration at the corners of the rectangular electrodes causing burns to the skin; the electrodes and the skin are connected with a special conductive gel to prevent saline from leaking from the sponge to form other stimulation pathways that damage the skin tissue.

[0038] (4) The electrical stimulation system of the present invention can be provided with a visualization unit to provide real-time feedback and visualization functions, so that the user can intuitively understand and adjust the stimulation effect, ensuring the accuracy and effectiveness of each treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the structure of a transcranial electrical stimulation system for alleviating skin reactions;

[0040] Figure 2 A flowchart of an exemplary solution algorithm executed in a stimulation parameter solution unit;

[0041] Figure 3 Schematic diagram of equivalent waveforms for the three waveform synthesis strategies;

[0042] Figure 4 A schematic diagram of the structure of another transcranial electrical stimulation system for alleviating skin reactions;

[0043] Figure 5 This is an electric field distribution diagram obtained by using the transcranial electrical stimulation system to treat depression in the embodiment;

[0044] Figure 6 The figures are the comparative results of pain evaluation after conventional transcranial electrical stimulation and transcranial electrical stimulation of the present invention. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in the various embodiments of the present invention can be combined accordingly without conflicting with each other.

[0046] In the description of the present invention, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0047] In the description of the present invention, it should be understood that the terms "first" and "second" are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being described. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features.

[0048] The traditional transcranial electrical stimulation system outputs a single-ended stimulation signal, and a pair of stimulation electrodes consisting of a cathode and an anode apply the stimulation current to the intervention individual. The inventive concept of the present invention is to decompose the single-ended stimulation signal into multiple groups of stimulation signal outputs, so that the spatial treatment field (i.e., stimulation field potential) distribution formed by them is equivalent to the spatial treatment field distribution formed by the single-ended stimulation signal, thereby reducing the skin reaction under the stimulation electrode. However, due to the differences in the head of each individual, the same stimulation will produce different spatial treatment field distributions on different heads. Therefore, the present invention needs to solve the stimulation parameters for the individual in advance. The specific implementation of the present invention is described in detail below.

[0049] like Figure 1 As shown, in a preferred embodiment of the present invention, a transcranial electrical stimulation system for alleviating skin reactions is provided, which includes a control unit 1 and a stimulation parameter solving unit 2 connected to the control unit 1, an electrical stimulation unit 5, a stimulation electrode cap 6, and a power supply unit 9.

[0050] In the transcranial electrical stimulation system described above, the control unit 1 serves as the core data processing and control module in the slave computer, responsible for processing system data information and controlling the various functional modules connected thereto, while also being responsible for information exchange with the master computer and external devices. In an embodiment of the present invention, the control unit 1 may be comprised of a high-performance microprocessor that is connected to other units within the system via a high-speed data bus and uses an embedded operating system to manage task scheduling and resource allocation, ensuring real-time system response and stable operation, thereby enabling overall system information processing and functional control.

[0051] In the above-mentioned transcranial electrical stimulation system of the present invention, a plurality of stimulation electrodes are distributedly arranged in the stimulation electrode cap 6. Theoretically, the number of stimulation electrodes is at least two, but when the output channel of the electrical stimulation unit 5 and the arrangement space of the stimulation electrode cap 6 itself meet the requirements, more electrodes can generally be provided, preferably 4 to 24 electrodes, so as to facilitate the dispersion of electrical stimulation. In an embodiment of the present invention, the stimulation electrode cap 6 is a customized metal fabric cap having denser electrode sites than traditional electrode caps for obtaining the best electrode site combination. Moreover, the stimulation electrodes in the stimulation electrode cap 6 can be circular electrodes to avoid the generation of higher current peak concentrations at the corners of rectangular electrodes that may burn the skin.

[0052] In the above-mentioned transcranial electrical stimulation system of the present invention, the electrical stimulation unit 5 is used to generate a stimulation waveform with adjustable parameters. The electrical stimulation unit 5 can be implemented with reference to the transcranial electrical stimulation system in the prior art. It is composed of a constant current source, a booster pump, and a waveform generator, and can output an electrical stimulation waveform with adjustable current, frequency, and time interval parameters. The waveform synthesizer, constant current source, and booster pump of the electrical stimulation unit can be finished products in the form of integrated chips, and the chip parameters of such chips can be modified by programming. In an embodiment of the present invention, the output channels of the electrical stimulation unit 5 can reach 24, the stimulation signal output voltage can reach 50V, and the stimulation current can be adjusted within 0.033~5mA.

[0053] In the above-mentioned transcranial electrical stimulation system of the present invention, the power supply unit 9 is used to supply power to other units in the entire system. The specific form and output voltage of the power supply unit 9 can be adjusted according to the design requirements of other units in the system, as long as it can provide a voltage output that meets the requirements. In an embodiment of the present invention, the power supply unit includes a linear voltage regulator module and a power supply filter module. The linear voltage regulator module is used to provide a stable DC power supply, and the power supply filter module is used to suppress voltage ripple and external environmental interference so that the power supply can output stably.

[0054] In the transcranial electrical stimulation system described above, the stimulation parameter solving unit 2 is a core unit. Its function is to develop a more reasonable multi-electrode stimulation parameter scheme based on the causes of adverse skin reactions. This is achieved based on finite element analysis and electric field simulation technology. Specifically, the stimulation parameter solving unit 2 can simulate the head of the individual being treated and generate equivalent stimulation parameters for each stimulation electrode in the stimulation electrode cap 6, thereby providing a stimulation mode that is similar to the traditional single-electrode stimulation mode but can reduce skin reactions.

[0055] It should be noted that for ease of description, the present invention refers to the traditional single-ended stimulation protocol, where a pair of stimulation electrodes, consisting of a cathode and an anode, are used to apply stimulation current to the head of the intervention subject, as a single-electrode stimulation protocol. The stimulation parameters in this protocol, such as stimulation intensity, duration, and target location, can generally be determined by the physician.

[0056] In the embodiment of the present invention, the specific stimulation parameter solving process in the stimulation parameter solving unit 2 is as follows:

[0057] A) Read the imaging data of the individual to be intervened and construct the individual head model through brain tissue segmentation and 3D reconstruction;

[0058] B) Finite element simulation is used to determine the spatial therapeutic field distribution (i.e., the simulated electric field distribution within the brain generated by the stimulation current) generated by the preset single-electrode stimulation scheme on the head of the individual being treated.

[0059] C) combining the model of the stimulation electrode cap 6 onto the individual head model, and obtaining the stimulation parameters required for each stimulation electrode in the stimulation electrode cap 6 to equivalently form the spatial treatment field distribution on the head of the individual to be intervened through finite element simulation.

[0060] It should be noted that the imaging data of the individual undergoing transcranial electrical stimulation can be imported by the user or automatically linked or read from relevant medical equipment via software. The process of constructing an individual head model based on the imaging data through brain tissue segmentation and three-dimensional reconstruction is currently available and can be selected based on the type of imaging data.

[0061] It should be noted that although the stimulation electrode cap 6 has multiple stimulation electrodes, there is a linear superposition effect between the spatial therapeutic field distribution formed by the stimulation electrodes in the brain and the electrical stimulation intensity. Therefore, the stimulation parameter solving unit 2 of the present invention does not need to simultaneously perform a joint simulation of the spatial therapeutic field distribution of multiple stimulation electrodes. It is only necessary to perform a finite element simulation for each stimulation electrode in the stimulation electrode cap 6 separately to find the electrical stimulation intensity corresponding to this stimulation electrode that can form an equivalent spatial therapeutic field distribution with the single-electrode stimulation scheme on the head of the individual to be intervened. When waveform coupling is subsequently performed, the electrical stimulation intensity can be adjusted based on the linear superposition effect to generate the required equivalent waveform.

[0062] It should be noted that the stimulation parameter solving unit 2 can be integrated into either a slave or a host computer. Considering that the stimulation parameter solving unit 2 requires simulation, which consumes a large amount of computing resources, it is preferred to implement the stimulation parameter solving unit 2 in the form of a host computer. That is, the stimulation parameter solving unit 2 is a software functional module installed in a host computer such as a PC or server. The host computer establishes a communication connection with the slave computer in the transcranial electrical stimulation system to transfer data between them.

[0063] In a preferred embodiment of the present invention, an exemplary solution algorithm process executed in the stimulation parameter solution unit 2 is provided, such as Figure 2 As shown, the specific steps are as follows:

[0064] 1) Data import: Import the MRI or CT imaging data of the individual to be treated with transcranial electrical stimulation into the system.

[0065] 2) Preprocessing: Perform brain tissue segmentation (e.g., scalp, skull, cerebrospinal fluid, gray matter, white matter, etc.) on the imported image data, and perform post-processing (e.g., smoothing filtering, denoising, etc.) on the segmented images. In embodiments of the present invention, brain tissue segmentation can be achieved using models such as Unet.

[0066] 3) Three-dimensional reconstruction: The processed image is reconstructed in three dimensions to generate an individual head model (also referred to as an individual head model in the present invention), and the model of a single stimulation electrode and a stimulation electrode cap 6 in the single-electrode stimulation scheme is placed on the individual head model to form a finite element model. In an embodiment of the present invention, three-dimensional reconstruction can be achieved by software such as Comsol. A single stimulation electrode or a stimulation electrode cap 6 is also constructed in the finite element model, and a single stimulation electrode or a stimulation electrode cap 6 can be selected to be enabled for simulation later according to simulation requirements. It should also be noted that, for the convenience of simulation, the model of the stimulation electrode cap 6 can be simplified to the various stimulation electrodes contained therein, and other components of the stimulation electrode cap 6 except the stimulation electrode can be temporarily ignored because they do not have a substantial impact on the electric field distribution.

[0067] 4) Finite element meshing: Finite element meshing is performed on the finite element simulation model, and the mesh parameters (mainly dielectric parameters) required for finite element simulation are assigned to different tissues (the brain in the individual head model) and components (a single transcranial stimulation electrode and the stimulation electrode cap 6).

[0068] 5) Field distribution calculation: Place a single transcranial stimulation electrode at the expected stimulation target location according to the requirements of the single-electrode stimulation scheme, and calculate the electric field distribution through software simulation, which is the equivalent spatial treatment field distribution required later; at the same time, combine the model of the stimulation electrode cap 6 containing multiple stimulation electrodes on the head, and adjust the position and stimulation parameters of each stimulation electrode in turn so that the generated electric field distribution is equivalent to the electric field distribution generated by the aforementioned single stimulation electrode.

[0069] Thus, the stimulation parameter solving unit 2 can obtain a set of equivalent stimulation parameters for each stimulation electrode in the stimulation electrode cap 6 through simulation. Under these equivalent stimulation parameters, each stimulation electrode can generate an electric field distribution equivalent to that generated by a single stimulation electrode in the aforementioned single-electrode stimulation scheme. The equivalent stimulation parameters for each stimulation electrode generally include its location and stimulation intensity (i.e., current intensity).

[0070] As mentioned above, based on this multi-electrode stimulation scheme, the electrical stimulation intensity can be regulated based on the linear superposition effect to generate the required equivalent waveform when waveform coupling is performed. Therefore, the present invention proposes a waveform synthesis strategy that matches the multi-electrode stimulation scheme. In the waveform synthesis strategy, stimulation electrodes at multiple different positions disperse alternate stimulation in the time domain or disperse the original stimulation intensity in terms of stimulation intensity, but the total stimulation duration and the total stimulation intensity at any moment remain consistent with the single-electrode stimulation scheme.

[0071] The core concept of this waveform synthesis strategy is to spatially disperse the electrical stimulation of a single target across multiple points, thereby reducing the intensity of stimulation at a single target or providing intermittent stimulation of each target. However, from a temporal perspective, the electrical stimulation remains continuous, and the total duration and intensity of stimulation at any given moment remain consistent with those of a single-electrode stimulation protocol. The linear superposition effect ensures that the resulting therapeutic field distribution within the brain remains equivalent to that of a single-electrode stimulation protocol.

[0072] The specific form of the above waveform synthesis strategy can be reasonably optimized according to actual conditions, as long as it can reduce the intensity of electrical stimulation at a single target location or space the stimulation in the time domain. In the embodiment of the present invention, three optimized waveform synthesis strategies are provided, and their respective equivalent waveforms are as follows: Figure 3 For ease of description, assuming that a single stimulation electrode in a single-electrode stimulation scheme is used for intervention treatment, the stimulation intensity is p, the stimulation duration is t, and the energy applied to the intervention individual is E=p*t.

[0073] In the first waveform synthesis strategy, multiple stimulation electrodes at different positions in the stimulation electrode cap 6 simultaneously perform continuous electrical stimulation, and the total stimulation duration of each stimulation electrode is consistent with the total stimulation duration in the single-electrode stimulation scheme, and the sum of the stimulation intensities of all stimulation electrodes is consistent with the stimulation intensity in the single-electrode stimulation scheme. Under this waveform synthesis strategy, the stimulation intensity (i.e., the magnitude of the stimulation current) applied by each stimulation electrode is p n , the stimulation duration is t, all stimulation electrodes apply stimulation current at the same time, then the energy applied to the intervention individual is E=(p1+p2+…+p n )*t, which is equivalent to E=p*t in the single-electrode stimulation scheme.

[0074] In the second waveform synthesis strategy, multiple stimulation electrodes at different positions in the stimulation electrode cap 6 alternately perform electrical stimulation. The total duration of the alternating stimulation of all stimulation electrodes is consistent with the total stimulation duration in the single-electrode stimulation scheme, but at a single moment only one stimulation electrode outputs electrical stimulation with the same stimulation intensity as in the single-electrode stimulation scheme. Under this waveform synthesis strategy, the stimulation intensity applied by each stimulation electrode is p, and the stimulation duration of the i-th stimulation electrode is t i , i = 1, 2, ..., n, then the energy applied to the intervention individual is E = p (t1 + t2 + ... + t n ), which is equivalent to E=p*t in the single-electrode stimulation scheme.

[0075] In the third waveform synthesis strategy, electrical stimulation is performed alternately by stimulation electrodes at multiple different positions in the stimulation electrode cap 6. The total duration of the alternating stimulation of all stimulation electrodes is consistent with the total stimulation duration in the single-electrode stimulation scheme, but at a single moment, the sum of the stimulation intensities output by at least two stimulation electrodes is consistent with the electrical stimulation in the single-electrode stimulation scheme. In fact, the third waveform synthesis strategy is a combination of the first two waveform synthesis strategies, which simultaneously disperses the stimulation intensity and the stimulation duration. Under this waveform synthesis strategy, the stimulation intensity applied by each stimulation electrode is p / n, and the stimulation duration of the i-th stimulation electrode is t' i , i=1,2,…,n, and t'1+t'2+…+t' n =n*t, then the energy applied to the intervention individual is E=(p / n)*(t'1+t'2+…+t' n ), which is equivalent to E=p*t in the single-electrode stimulation scheme.

[0076] After the stimulation parameter solving unit 2 outputs equivalent stimulation parameters for each stimulation electrode in the stimulation electrode cap 6, it can be saved in the control unit 1. Since the electrical stimulation unit 5 has multiple output channels, the control unit 1 can control the electrical stimulation unit 5 to output an electrical stimulation waveform capable of alleviating skin reactions to each stimulation electrode in the stimulation electrode cap 6 according to a predefined waveform synthesis strategy based on the equivalent stimulation parameters of all stimulation electrodes in the stimulation electrode cap 6. The predefined waveform synthesis strategy here can be any of the three waveform synthesis strategies described above.

[0077] Therefore, in the above-mentioned transcranial electrical stimulation system of the present invention, a head model can be constructed according to the actual imaging data of the individual to be intervened, and the equivalent stimulation parameters under the multi-electrode stimulation scheme can be obtained by simulation. Then, according to the equivalent stimulation parameters, the stimulation electrode cap 6 is worn in actual application and the required waveform synthesis strategy is selected to perform actual transcranial electrical stimulation intervention treatment. Since the electrical stimulation intensity of a single stimulation electrode is reduced, or a single stimulation electrode is intermittently electrically stimulated, the skin reaction can be greatly reduced. Moreover, it was found in actual experiments that among the above-mentioned three waveform synthesis strategies, the second waveform synthesis strategy and the third waveform synthesis strategy are better than the first waveform synthesis strategy in reducing the skin reaction. That is, electrical stimulation is not applied continuously to a single target point, but is applied intermittently, which can leave a buffer time for the skin to adapt to the electrical stimulation and more effectively suppress the skin reaction.

[0078] In addition, in an embodiment of the present invention, considering that the stimulation parameters need to be generated through simulation in the above-mentioned transcranial electrical stimulation system, a visualization unit 3 can be further provided in the system. The visualization unit 3 can be connected to the control unit 1 or directly connected to the visualization unit 3, and is used to read the stimulation parameters of each stimulation electrode and the spatial treatment field distribution equivalently formed on the head of the individual to be intervened from the stimulation parameter solving unit 2, and visualize them according to a preset visualization mode. As a result, the electrical stimulation system has real-time feedback and visualization functions, allowing users to intuitively understand and adjust the stimulation effect, ensuring the accuracy and effectiveness of each treatment.

[0079] In addition, in an embodiment of the present invention, considering that the waveform synthesis strategy needs to be manually defined in the above-mentioned transcranial electrical stimulation system and that the stimulation parameters also need to be adjusted to a certain extent, a communication unit 8 can be further provided in the system to establish a connection with an external instruction input device and receive system control instructions input by the external instruction input device. The external instruction input device can be any device with an information input function, such as an information input device such as a keyboard, mouse, or touch screen, or a device with an information input function such as a mobile phone, tablet computer, or PC. The specific external instruction input device is different in form, and the required communication unit 8 is also different. The communication unit is connected to the control unit 1 and communicates with the external instruction input device in a wired or wireless manner. The system control instructions input by the external instruction input device are instructions for setting the waveform synthesis strategy and instructions for adjusting the electrical stimulation treatment parameters (such as electrical stimulation intensity, electrical stimulation duration, etc.).

[0080] In addition, in an embodiment of the present invention, in order to improve the reliability of the above-mentioned transcranial electrical stimulation system, an impedance detection unit 7 connected to the control unit 1 can be further provided in the system. The impedance detection unit 7 is used to detect the potential difference between each channel in the electrical stimulation unit 5 and the real-time output current in real time, so as to calculate the equivalent impedance to feedback the electrode shedding situation. The impedance detection unit 7 can use the sampling resistor method to detect the real-time current and the resistance voltage sampling method to detect the electrode end voltage. In addition to being used to feedback the electrode shedding situation, the impedance detection unit 7 can also feed back the impedance information to the control unit 1. By auxiliary stimulation parameter setting, the stimulation current can be adjusted by real-time contact impedance to reduce skin damage.

[0081] In addition, in an embodiment of the present invention, in the above-mentioned transcranial electrical stimulation system, since there are multiple stimulation electrodes, and each stimulation electrode needs to coordinate the output coupling of an equivalent waveform. In theory, this coupling control function for the waveform can be implemented by software or hardware. When the software function is implemented, a waveform control module for regulating the multiple output channels of the electrical stimulation unit 5 can be integrated inside the control unit 1 to directly and independently control whether each output channel outputs a signal, so that the electrical stimulation waveform ultimately output to each stimulation electrode in the stimulation electrode cap 6 meets the predefined waveform synthesis strategy. In addition, when implemented by hardware, a switch switching unit 4 connected to the control unit 1 and the electrical stimulation unit 5 can be further provided in the system. Under the control of the control unit 1, the switch switching unit 4 performs hardware-level switch control on each output channel of the electrical stimulation unit 5, so that the electrical stimulation waveform ultimately output to each stimulation electrode in the stimulation electrode cap 6 meets the predefined waveform synthesis strategy.

[0082] Therefore, in a preferred embodiment of the present invention, Figure 1 Based on the transcranial electrical stimulation system shown in FIG, the above-mentioned visualization unit 3, communication unit 8, impedance detection unit 7 and switch switching unit 4 are further provided to provide a more complete transcranial electrical stimulation system form, specifically as shown in FIG. Figure 4 As mentioned above, the present invention preferably implements the stimulation parameter solving unit 2 in the form of a host computer, so the visualization unit 3 can also be integrated into the host computer. Of course, a visualization hardware device can also be provided separately.

[0083] In addition, in another embodiment of the present invention, a parameter optimization method based on any of the above transcranial electrical stimulation systems is provided, wherein the specific optimization process includes:

[0084] S1. Obtain imaging data of the individual to be intervened, perform brain tissue segmentation on the imaging data, and then form an individual head model through three-dimensional reconstruction;

[0085] S2. Determining an original stimulation target and original electrical stimulation parameters according to a preset single-electrode stimulation protocol, constructing a single stimulation electrode at a position corresponding to the original stimulation target on the individual head model, then performing finite element meshing to assign dielectric parameters required for simulation to different tissues and the stimulation electrode; performing finite element simulation of transcranial electrical stimulation according to the original electrical stimulation parameters to obtain a spatial treatment field distribution formed by the single stimulation electrode in the individual head model;

[0086] S3. Assembling the model of the stimulation electrode cap 6 onto the individual head model, re-performing finite element meshing, and assigning dielectric parameters required for simulation to different tissues and the stimulation electrode cap 6; then searching stimulation parameters for each stimulation electrode in the stimulation electrode cap 6 to find equivalent stimulation parameters that can form the spatial treatment field distribution closest to that of a single stimulation electrode in the individual head model;

[0087] S4. For each waveform synthesis strategy to be selected, finite element simulation is re-performed based on the equivalent stimulation parameters of each stimulation electrode in the stimulation electrode cap 6. The goal is to make the equivalent spatial treatment field distribution formed during the electrical stimulation treatment process as close as possible to the spatial treatment field distribution formed by a single stimulation electrode. The optimal waveform synthesis strategy is screened out and output as a result together with the equivalent stimulation parameters of each stimulation electrode.

[0088] It should be noted that the above-mentioned processes S1 to S3 are consistent with the processes executed in the aforementioned stimulation parameter solution unit 2. The purpose of setting the final step S4 is to ensure the accuracy of the final spatial treatment field distribution. Because although there is a linear superposition effect between the spatial treatment field distribution formed by the stimulation electrodes in the brain and the electrical stimulation intensity, in theory, the equivalent waveform can be controlled by controlling the stimulation intensity. However, in real applications, deviations are inevitable. Therefore, the optimal number and position of stimulation electrodes and equivalent stimulation parameters for linear superposition of the combination can be further determined through simulation. The results can be output as the optimal solution and visualized so that the actual operator can intuitively see the electrode layout, parameter setting requirements, and the actual distribution of the equivalent treatment field.

[0089] In order to verify the specific technical effects of the present invention, the application of the above-mentioned transcranial electrical stimulation system for alleviating skin reactions in specific scenarios and related experimental results are demonstrated below.

[0090] See also Figure 5 As shown, the electric field distribution diagram of the treatment of depression using the above-mentioned transcranial electrical stimulation system that can reduce skin reactions in an embodiment of the present invention is shown. When using traditional TES to treat patients with depression, the anode is placed on the left dorsolateral prefrontal cortex, and the cathode is placed above the right supraorbital area. The stimulation current is divided into two groups of 1mA and 2mA. The skin under the cathode of the two groups of patients has different degrees of redness and damage, and the damage of the 2mA group is more serious. In this embodiment, 4 stimulation electrodes are arranged, and each stimulation electrode outputs a 0.5mA stimulation current at its respective target position according to the determined equivalent stimulation parameters. The duration is consistent with the single stimulation electrode scheme, which is equivalent to a 2mA stimulation current in traditional applications. The results show that this multi-electrode stimulation scheme can reduce the thermal effect of the current under the cathode, and the erythema on the skin surface is alleviated.

[0091] Also, see Figure 6In another experiment, a comparison of pain assessment results after conventional transcranial electrical stimulation and transcranial electrical stimulation treatment according to the present invention was demonstrated using a visual analogue scale (VAS) in the same group of subjects. The visual analogue scale (VAS), also known as the visual analogue scale or visual analogue scale, is a widely used method for assessing pain. A flexible ruler approximately 10 cm long is marked on one side with 10 scale marks, with "0" and "10" at either end. "0" indicates no pain, and "10" indicates unbearable, intense pain. In clinical use, the scaled side faces away from the patient, and the patient marks the corresponding location on the ruler that represents their pain level. The physician then assigns a score based on the location marked. Clinical assessments use a scale of 0-2 for excellent, 3-5 for good, 6-8 for acceptable, and >8 for poor. Using the same method before and after treatment allows for more objective scoring and evaluation of the effectiveness of pain treatment. In the embodiments of the present invention, a visual analog scale was used to compare and evaluate the pain assessment of conventional transcranial electrical stimulation and the electrical stimulation of the present invention. In the experiment of the present invention, the same group of subjects were divided into two groups, one for conventional transcranial electrical stimulation (two electrodes, one electrode placed on the left primary motor cortex and one electrode placed on the right primary motor cortex, the stimulation current was 2 mA, and the stimulation frequency was 10 Hz), and the other for the electrical stimulation group of the present invention (five stimulation electrodes were used in the transcranial electrical stimulation system, and the electrode positions and stimulation current sizes were: FC3 (1 mA), C3 (0.5 mA), C5 (0.5 mA), C4 (-1 mA), C6 (-1 mA)). The intervention time for both groups was 20 minutes. Figure 6 The comparison results of the pain visual analog scale in the literature show that compared with conventional transcranial electrical stimulation, the transcranial electrical stimulation system and application method of the present invention can reduce skin reactions.

[0092] The embodiments described above are merely some preferred implementations of the present invention and are not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A transcranial electrical stimulation system for alleviating skin reactions, characterized in that: It includes a control unit and a stimulation parameter solving unit, an electrical stimulation unit, a stimulation electrode cap, and a power supply unit connected to the control unit; The stimulation electrode cap is provided with a plurality of stimulation electrodes distributedly arranged therein; the power supply unit is used to supply power to other units; The stimulation parameter solving unit is used to read the imaging data of the individual to be intervened, construct an individual head model through brain tissue segmentation and three-dimensional reconstruction, first obtain the spatial treatment field distribution formed by the preset single-electrode stimulation scheme on the head of the individual to be intervened through simulation, then combine the model of the stimulation electrode cap with the individual head model, and obtain the stimulation parameters required for each stimulation electrode in the stimulation electrode cap to equivalently form the spatial treatment field distribution on the head of the individual to be intervened through simulation; The electrical stimulation unit has multiple output channels, and the control unit is used to save the stimulation parameters of all stimulation electrodes in the stimulation electrode cap, and control the electrical stimulation unit to output an electrical stimulation waveform capable of alleviating skin reaction to each stimulation electrode in the stimulation electrode cap according to a predefined waveform synthesis strategy; In the waveform synthesis strategy, electrical stimulation is performed alternately by stimulation electrodes at multiple different positions in the stimulation electrode cap, and the total duration of the alternating stimulation of all stimulation electrodes is consistent with the total stimulation duration in the single-electrode stimulation scheme, but at a single moment, the sum of the stimulation intensities output by at least two stimulation electrodes is consistent with the electrical stimulation in the single-electrode stimulation scheme.

2. The transcranial electrical stimulation system for alleviating skin reactions according to claim 1, wherein: It also includes a visualization unit for reading the stimulation parameters of each stimulation electrode and the spatial treatment field distribution equivalently formed on the head of the individual to be intervened from the stimulation parameter solving unit, and visually displaying them according to a preset visualization mode.

3. The transcranial electrical stimulation system for alleviating skin reactions according to claim 1, wherein: It also includes a communication unit connected to the control unit, which is used to establish a connection with an external instruction input device and receive system control instructions input by the external instruction input device. The system control instructions input by the external instruction input device are setting instructions for the waveform synthesis strategy or electrical stimulation treatment parameters.

4. The transcranial electrical stimulation system for alleviating skin reactions according to claim 1, wherein: The stimulation electrodes in the stimulation electrode cap are circular electrodes.

5. The transcranial electrical stimulation system for alleviating skin reactions according to claim 1, wherein: It also includes an impedance detection unit connected to the control unit, which is used to detect the potential difference between each channel in the electrical stimulation unit and the real-time output current, so as to calculate the equivalent impedance to feedback the electrode detachment situation.

6. The transcranial electrical stimulation system for alleviating skin reactions according to claim 1, wherein: It also includes a switching unit connected to the control unit and the electrical stimulation unit. Under the control of the control unit, the switching unit performs switching control on each output channel of the electrical stimulation unit so that the electrical stimulation waveform ultimately output to each stimulation electrode in the stimulation electrode cap meets the predefined waveform synthesis strategy.

7. A parameter optimization method for a transcranial electrical stimulation system for alleviating skin reactions according to any one of claims 1 to 6, characterized in that: include: S1. Obtain imaging data of the individual to be intervened, perform brain tissue segmentation on the imaging data, and then form an individual head model through three-dimensional reconstruction; S2. Determining an original stimulation target and original electrical stimulation parameters according to a preset single-electrode stimulation protocol, constructing a single stimulation electrode at a position corresponding to the original stimulation target on the individual head model, then performing finite element meshing to assign dielectric parameters required for simulation to different tissues and the stimulation electrode; performing finite element simulation of transcranial electrical stimulation according to the original electrical stimulation parameters to obtain a spatial treatment field distribution formed by the single stimulation electrode in the individual head model; S3. Assembling the model of the stimulation electrode cap onto the individual head model, re-performing finite element meshing, and assigning dielectric parameters required for simulation to different tissues and the stimulation electrode cap; then searching stimulation parameters for each stimulation electrode in the stimulation electrode cap to find equivalent stimulation parameters that can form the spatial treatment field distribution closest to that of a single stimulation electrode in the individual head model; S4. For each waveform synthesis strategy to be selected, finite element simulation is re-performed based on the equivalent stimulation parameters of each stimulation electrode in the stimulation electrode cap. The goal is to make the equivalent spatial treatment field distribution formed during the electrical stimulation treatment process as close as possible to the spatial treatment field distribution formed by a single stimulation electrode. The optimal waveform synthesis strategy is screened out and output as the result together with the equivalent stimulation parameters of each stimulation electrode.

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