Time domain interferometric pulsed magnetic field generator based on parallel resonance

Abstract

The application discloses a time-domain interference pulse magnetic field generator based on parallel resonance, comprising two pulse magnetic field generators with the same structure, namely a first pulse magnetic field generator and a second pulse magnetic field generator; the application adopts a high fundamental frequency, improves the induced electric field intensity under the same current level, and realizes time-domain interference transcranial magnetic stimulation with different frequencies by adjusting the difference frequency (less than 1 kHz) of the two sets of pulse magnetic field generators.

Description

Technical Field

[0001] This invention relates to the field of pulsed magnetic field generation, specifically a time-domain interference pulsed magnetic field generator based on parallel resonance. Background Technology

[0002] Because the magnetic field generated by a TMS coil decays rapidly in space, TMS stimulation depth is relatively shallow (generally no more than 3 cm), while the stimulation areas for treating depression often include non-superficial brain regions (>5 cm). Another key factor in achieving the therapeutic effect of TMS is the focal point of the induced electric field. When the target area is confined to a restricted region, stimulation of non-target areas can reduce clinical efficacy and even lead to harmful side effects. Considering the above characteristics of TMS and the need to stimulate deep brain regions, the trade-off between depth and focal point is crucial for the design of TMS coils.

[0003] Temporal interference (TI) stimulation is a potential non-invasive method for stimulating deep brain regions, thus avoiding cortical coverage. The concept of TI stimulation is that it provides multiple electric fields with relatively high but slightly different frequencies. Since the mechanism based on these nerve membranes with inherent low-pass filtering of electrical signals is widely accepted, neural electrical activity cannot follow very high-frequency oscillating electric fields. Therefore, during TI stimulation, neurons in the brain do not directly respond to these high-frequency electric fields. However, because the frequency difference is small (e.g., 10 Hz), the two applied fields will thus form a temporal interference field, with the envelope modulated oscillating at different frequencies, allowing neurons to follow the different frequencies. In traditional TI stimulation methods, electrodes are placed above the scalp, delivering current into the brain tissue to penetrate the skull. This raises concerns that the impedance of the skin electrodes may degrade the performance of current propagation. Meanwhile, the magnetic field generated by a TMS system is unaffected by the presence or absence of surrounding biological tissue, and due to the high impedance of the head tissue, the magnetic field does not undergo significant distortion. The stimulation waveform (and the resulting induced electric field waveform) and the amplitude of the stimulation in the coil (and the magnitude of the resulting induced electric field) are independent of the neural tissue; therefore, magnetic stimulation techniques may be more effective in implementing the TI method.

[0004] Current research on time-domain interferometric transcranial magnetic stimulation is mostly limited to simulation, with few biological experiments. Summary of the Invention

[0005] The purpose of this invention is to provide a time-domain interference pulse magnetic field generator based on parallel resonance, comprising two pulse magnetic field generators with identical structures, referred to as the first pulse magnetic field generator and the second pulse magnetic field generator;

[0006] The first pulsed magnetic field generator includes resistors R1 and R2, diodes D1, D2, D3, D4, and D5, switches S1, S2, S3, and S4, and a power supply. Capacitor C, capacitor C1, coil 1;

[0007] The first pulsed magnetic field generator includes a resistor. ,resistance ,diode ,diode ,diode ,diode ,diode ,switch ,switch ,switch ,switch ,power supply ,capacitance ,capacitance 1. Coil 2;

[0008] The difference between the output frequencies of the first pulse magnetic field generator and the second pulse magnetic field generator is adjustable;

[0009] By adjusting the difference in output frequency between the first and second pulse magnetic field generators, time-domain interference transcranial magnetic stimulation at different frequencies can be achieved.

[0010] Furthermore, the resonant unit (coil and capacitor C) parameters of the first and second pulse magnetic field generators are different. The coil parameters are determined by the actual parameters of the two coils, which may have slight differences due to manufacturing errors. The capacitor C parameters are also different, and the resonant frequency is mainly adjusted by the capacitor C.

[0011] Furthermore, the switching frequencies of the first pulse magnetic field generator and the second pulse magnetic field generator are different.

[0012] Furthermore, the circuit topology of the first pulse magnetic field generator is shown below:

[0013] power supply One end of the capacitor is grounded, and the other end is connected in series with resistor R1 and capacitor C1 before being grounded.

[0014] One end of resistor R1 is connected in series with resistor R2 and then connected to a buffer circuit.

[0015] Diode D5 is connected in parallel across resistor R2;

[0016] Switch S1, switch S2, diode D2, switch S3, diode D3, diode D4, switch S4, and diode D1 are connected in sequence to form a series circuit;

[0017] The buffer circuit is connected to coil 1.

[0018] Furthermore, the circuit topology of the second pulse magnetic field generator is shown below:

[0019] power supply One end is grounded, and the other end is connected in series with a resistor. ,capacitance Rear grounding;

[0020] One end of resistor R1 is connected in series with a resistor Then connect to the buffer circuit;

[0021] diode Parallel connection in resistor Both ends;

[0022] switch ,switch ,diode ,switch ,diode ,diode ,switch ,diode Connect them sequentially to form a series circuit;

[0023] The buffer circuit is connected to coil 2.

[0024] Furthermore, the working process of the first pulse magnetic field generator and the second pulse magnetic field generator includes a charging stage, an initial discharge stage, a parallel resonance stage, and a natural decay stage.

[0025] Furthermore, when the first pulse magnetic field generator is in the charging phase, switches S1, S2, S3, and S4 are all in the off state, and the circuit is equivalent to a first-order RC charging circuit. Through current limiting resistor To energy storage capacitor Charge;

[0026] When the second pulse magnetic field generator is in the charging phase, the switch... ,switch ,switch ,switch Both are in the off state, and the circuit is equivalent to a first-order RC charging circuit. Through current limiting resistor To energy storage capacitor Charge.

[0027] Furthermore, when the first pulse magnetic field generator is in the initial discharge phase, the switch... With switch Synchronous conduction, capacitor Through resistance Discharge to the LC parallel resonant module;

[0028] When the second pulse magnetic field generator is in the initial discharge phase, the switch... With switch Synchronous conduction, capacitor Through resistance Discharge to the LC parallel resonant module.

[0029] Furthermore, when the first pulse magnetic field generator and the second pulse magnetic field generator are in the parallel resonance stage, the operating frequency of the bridge arm switch is consistent with the circuit resonant frequency.

[0030] Furthermore, the difference between the output frequencies of the first pulse magnetic field generator and the second pulse magnetic field generator is less than 1 kHz.

[0031] This invention proposes a time-domain interferometric transcranial magnetic stimulation pulse magnetic field generator based on Burst mode parallel resonance. By increasing the fundamental frequency to enhance the induced electric field intensity in the target region and utilizing difference frequency boosting to shorten the effective stimulation time in Burst mode, the average power consumption and temperature rise of the system are significantly reduced. This design effectively alleviates the heat generation problem caused by continuous operation without significantly increasing system complexity and cost, providing a feasible path for large animal experiments and future human trials.

[0032] Beneficial effects:

[0033] By adopting the Burst operating mode combined with a parallel resonant structure, the average current and continuous heat generation of the system are significantly reduced, enabling the equipment to operate stably at higher outputs and promoting the advancement of experimental research from simulation and small animals to large animals and humans.

[0034] Targeted optimization of traditional parallel resonant circuits reduces circulating energy and reactive power loss, thereby improving the overall system efficiency.

[0035] By increasing the fundamental frequency to enhance the intensity of the induced electric field, a better neural modulation effect can be obtained under the same excitation conditions. At the same time, by increasing the difference frequency to shorten the duration of a single Burst, the temperature rise can be further suppressed.

[0036] The system has a simple structure, good engineering feasibility and clinical translation potential, and provides a new approach for the practical application of time-domain interferometric transcranial magnetic stimulation technology. Attached Figure Description

[0037] Figure 1 This refers to the overall circuit structure of the TI-TMS prototype.

[0038] Figure 2 The effect of input voltage on the system;

[0039] Figure 3 For circuit testing platform;

[0040] Figure 4 The voltage overshoot waveforms on switches S1-S4;

[0041] Figure 5 To optimize the voltage overshoot waveform on switches S1-S4;

[0042] Figure 6 Load current under different input voltages;

[0043] Figure 7 The waveforms are those of the load current, switching current, and resonant capacitor voltage.

[0044] Figure 8 For measuring induced electric fields;

[0045] Figure 9 A measurement platform for measuring the magnetic induction intensity at specific locations within a saline globus encephalopathy model;

[0046] Figure 10 The waveform of magnetic flux density measured in the stimulation region using a Tesla meter;

[0047] Figure 11 The distribution of the induced electric field in the target area;

[0048] Figure 12 The induced electric field is located outside the target area.

[0049] Figure 13 This is a schematic diagram of the coil arrangement. Detailed Implementation

[0050] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0051] Example 1:

[0052] See Figures 1 to 13 A time-domain interference pulse magnetic field generator based on parallel resonance includes two pulse magnetic field generators with the same structure, referred to as the first pulse magnetic field generator and the second pulse magnetic field generator;

[0053] The first pulsed magnetic field generator includes resistors R1 and R2, diodes D1, D2, D3, D4, and D5, switches S1, S2, S3, and S4, and a power supply. Capacitor C, capacitor C1, coil 1;

[0054] Coil 1 in the circuit Figure 1The equivalent values ​​are resistor RL and inductor L.

[0055] The first pulsed magnetic field generator includes a resistor. ,resistance ,diode ,diode ,diode ,diode ,diode ,switch ,switch ,switch ,switch ,power supply ,capacitance ,capacitance 1. Coil 2;

[0056] Coil 1 and coil 2 are arranged symmetrically, as follows: Figure 11 As shown, deflection angle exist Adjustable within a certain range, in this embodiment The coil does not come into contact with the brain of the person being treated; a distance of more than 5mm is generally maintained.

[0057] The difference between the output frequencies of the first pulse magnetic field generator and the second pulse magnetic field generator is adjustable;

[0058] By adjusting the difference in output frequency between the first and second pulse magnetic field generators, time-domain interference transcranial magnetic stimulation at different frequencies can be achieved.

[0059] Example 2:

[0060] The time-domain interference pulse magnetic field generator based on parallel resonance is technically the same as in Embodiment 1, except that the resonant unit (coil and capacitor C) parameters of the first and second pulse magnetic field generators are different. The coil parameters are determined by the actual parameters of the two coils, which may have slight differences due to manufacturing errors. The capacitor C parameters are different, and the resonant frequency is mainly adjusted by the capacitor C.

[0061] Example 3:

[0062] The time-domain interference pulsed magnetic field generator based on parallel resonance has the same technical content as any one of Embodiments 1-2. Further, the switching frequencies of the first and second pulsed magnetic field generators are different. The switching frequency is greater than 2kHz; in this embodiment, the switching frequencies are 10kHz and 10.5kHz, respectively, and the difference frequency must be less than 1kHz. In this paper, the difference frequency is selected as 500Hz.

[0063] Example 4:

[0064] The time-domain interference pulse magnetic field generator based on parallel resonance has the same technical content as any one of embodiments 1-3. Furthermore, the circuit topology of the first pulse magnetic field generator is shown below:

[0065] power supply One end of the capacitor is grounded, and the other end is connected in series with resistor R1 and capacitor C1 before being grounded.

[0066] One end of resistor R1 is connected in series with resistor R2 and then connected to a buffer circuit; the buffer circuit is a set of diodes, capacitors and resistors connected in parallel across switches S1-S4.

[0067] Diode D5 is connected in parallel across resistor R2;

[0068] Switch S1, switch S2, diode D2, switch S3, diode D3, diode D4, switch S4, and diode D1 are connected in sequence to form a series circuit;

[0069] The buffer circuit is connected to coil 1.

[0070] Example 5:

[0071] The time-domain interference pulse magnetic field generator based on parallel resonance has the same technical content as any one of embodiments 1-4. Furthermore, the circuit topology of the second pulse magnetic field generator is shown below:

[0072] power supply One end is grounded, and the other end is connected in series with a resistor. ,capacitance Rear grounding;

[0073] One end of resistor R1 is connected in series with a resistor Then connect to the buffer circuit;

[0074] diode Parallel connection in resistor Both ends;

[0075] switch ,switch ,diode ,switch ,diode ,diode ,switch ,diode Connect them sequentially to form a series circuit;

[0076] The buffer circuit is connected to coil 2.

[0077] Example 6:

[0078] The time-domain interference pulse magnetic field generator based on parallel resonance has the same technical content as any one of embodiments 1-5. Furthermore, the working process of the first pulse magnetic field generator and the second pulse magnetic field generator includes a charging stage, an initial discharge stage, a parallel resonance stage, and a natural decay stage.

[0079] The natural decay phase occurs when stimulation needs to be stopped. After all switches are turned off, the coil current cannot immediately drop to 0 due to the energy stored in the resonant system, resulting in a resonant decay phase.

[0080] Example 7:

[0081] The time-domain interference pulse magnetic field generator based on parallel resonance has the same technical content as any one of embodiments 1-6. Further, when the first pulse magnetic field generator is in the charging stage, switches S1, S2, S3, and S4 are all in the off state, and the circuit is equivalent to a first-order RC charging circuit. Through current limiting resistor To energy storage capacitor Charge;

[0082] When the second pulse magnetic field generator is in the charging phase, the switch... ,switch ,switch ,switch Both are in the off state, and the circuit is equivalent to a first-order RC charging circuit. Through current limiting resistor To energy storage capacitor Charge.

[0083] Example 8:

[0084] The time-domain interference pulse magnetic field generator based on parallel resonance has the same technical content as any one of embodiments 1-7. Further, when the first pulse magnetic field generator is in the initial discharge stage, the switch... With switch Synchronous conduction, capacitor Through resistance Discharge into the LC parallel resonant module (including coils (L, RL) and capacitor C);

[0085] When the second pulse magnetic field generator is in the initial discharge phase, the switch... With switch Synchronous conduction, capacitor Through resistance Discharge to the LC parallel resonant module.

[0086] Example 9:

[0087] The time-domain interference pulse magnetic field generator based on parallel resonance has the same technical content as any one of embodiments 1-8. Furthermore, when the first pulse magnetic field generator and the second pulse magnetic field generator are in the parallel resonance stage, the operating frequency of the bridge arm switch is consistent with the circuit resonant frequency.

[0088] Example 10:

[0089] The time-domain interference pulse magnetic field generator based on parallel resonance has the same technical content as any one of embodiments 1-9. Further, the difference between the output frequencies of the first pulse magnetic field generator and the second pulse magnetic field generator is less than 1 kHz.

[0090] Example 11:

[0091] A time-domain interference pulse magnetic field generator based on parallel resonance is described below:

[0092] The circuit topology of this invention patent is as follows: Figure 1 As shown, the circuit consists of two pulse magnetic field generators with identical principles and structures, differing only in some component parameters and switching frequencies. Based on the LC parallel resonance principle, it achieves current multiplication and high-efficiency energy output through the timing control of a full-bridge switch. The output frequencies of the two circuits are 10kHz and 10.5kHz, respectively. Since the two circuits operate on the same principle, the following analysis will focus on one of the circuits.

[0093] Its core working process can be divided into four stages: charging, initial discharging, parallel resonance, and natural decay. The circuit state and energy conversion mechanism of each stage are described below. During the charging stage, the H-bridge switch... When in the off state, the circuit is equivalent to a first-order RC charging circuit, with the energy storage capacitor... DC power supply Through current limiting resistor During charging, the voltage increases exponentially. To ensure sufficient energy during the subsequent discharge phase, The capacitance is much larger than the resonant capacitor C to meet the energy requirements of high-power pulse output. During the initial discharge phase, the switch... and Synchronous conduction, pass Discharge the LC parallel resonant module. Since the initial voltage of the resonant capacitor C is zero, and... Voltages can reach hundreds of volts, and large voltage differences can easily trigger instantaneous current surges. Through proper setting... The resistance value effectively suppresses inrush current and protects switching devices. The inductor current during this stage... The pulse rises in an underdamped oscillating manner, its change satisfying the second-order circuit response expression, with a wide pulse width and low peak value. After entering the parallel resonance stage, the switching frequency of the adjacent bridge arms is adjusted to match the circuit's resonant frequency. When the inductance is consistent, the circuit enters steady-state resonance. The resonant frequency is determined by the inductance L, capacitance C, and coil internal resistance. Joint decision:

[0094] (1)

[0095] Switch single action time Take half a cycle ( This causes the LC circuit to oscillate continuously under switching excitation. At this time, the circuit's equivalent impedance... For purely resistive applications, the switching current... With capacitor voltage Satisfying Ohm's law, energy is stored alternately between L and C. A major innovation of this invention is the addition of a series diode to the switch, which suppresses the short-circuit loop of the resonant capacitor C during circuit commutation, suppressing switch current overshoot and energy loss. The quality factor of a similar conventional circuit is about 4.5, while the quality factor of this invention reaches 6.79.

[0096] Implementation Example 12:

[0097] To systematically verify the output capability of this invention under different input voltages, this study is based on Figure 1 The equivalent model shown was used to build the PSpice simulation platform, and the main simulation parameters are shown in Table 1.

[0098] Table 1 Main Simulation Parameters

[0099]

[0100] The output capability of the developed parallel resonant circuit under different input voltages was investigated in simulation, and the amplification factor and quality factor of the circuit were calculated. The results are as follows: Figure 2 As shown, it can be seen that the system quality factor and amplification factor tend to stabilize under different input voltage conditions.

[0101] Implementation Example 13:

[0102] To verify the feasibility of this invention, a corresponding experimental prototype was developed and a testing facility was constructed. Figure 3 The test platform shown in the figure has the main experimental parameters shown in Table 2.

[0103] Table 2 Main experimental parameters

[0104]

[0105] Experiments have shown that due to the parasitic inductance of the circuit, overvoltage can occur when the switch is turned off, such as... Figure 4As shown, a buffer circuit is required. Traditional RCD buffer circuits suffer from high-frequency losses, while low-loss buffer circuits with energy recovery often have complex topologies, requiring the introduction of active devices. Generally, the time constant τ of an RCD buffer circuit is designed to be 1 / 3 of the switching cycle. This ensures the buffer capacitor fully discharges before each switch closure, effectively suppressing overshoot. However, this also means the buffer capacitor needs to be fully charged and discharged with each switching action, resulting in high losses. Therefore, this invention increases the buffer resistance, thereby increasing the time constant of the buffer circuit and suppressing the discharge of the resonant capacitor, maintaining the resonant capacitor voltage above the switch-off voltage within a pulse train. Experimental testing shows that the optimized buffer circuit effectively suppresses voltage overshoot, as... Figure 5 As shown, it has low energy consumption.

[0106] After experimental testing, the load current waveform under different input voltages is as follows: Figure 6 As shown, when the input voltage is 700V, the load current reaches more than 1000 A, which meets the requirements for transcranial magnetic stimulation to induce action potential. After the load current reaches its maximum value, the resonant system enters a stable working state. The energy consumed by the internal resistance of the resonant system is equal to the energy obtained from the energy storage capacitor. The consumed energy can be calculated based on the instantaneous integral of the resonant unit port (Equation (2)), and then the system quality factor (Equation (3)) can be calculated.

[0107] (2)

[0108] (3)

[0109] Based on the experimentally measured load current, switching current, and resonant capacitor voltage waveforms ( Figure 7 Based on the circuit parameters, the circuit quality factor Q = 5.71, which is higher than the 4.5 of the traditional resonant circuit, indicating lower losses and higher efficiency. According to the measurement results, the maximum current on the switch is 500 A, while the maximum load current is 1000 A, and the system amplification factor... .

[0110] In summary, the Burst-mode parallel resonant time-domain interferometric transcranial magnetic stimulation pulse magnetic field generator proposed in this invention uses the Burst mode to reduce stimulation time, achieving controllable energy loss under high current and high stimulation intensity, laying the foundation for time-domain interferometric transcranial magnetic stimulation under safe temperatures; based on a multi-dimensional strategy, it reduces the system's energy loss, improves system efficiency, and gives the system a higher quality factor.

[0111] Implementation Example 14:

[0112] This paper uses a teslameter to measure the magnetic induction intensity at a specific location within a saline bulboencephalogram. The measurement platform is shown in Figure 9. The experimental platform consists of a TI-TMS prototype, a spherical glass container with a radius of 100 mm filled with saline, an F8C-T stimulation coil, a precision moving platform, a teslameter, and an oscilloscope.

[0113] During the experiment, sinusoidal excitation currents with an amplitude of 1000A were applied to coils 1 and 2, respectively, with frequencies of 10 kHz and 10.5 kHz, and a frequency difference of 500 Hz, thus forming the dual-frequency excitation conditions required by TI-TMS. The magnetic flux density waveform measured in the stimulation region by a teslameter is shown below. Figure 10 As shown in the figure. The results show that the measured magnetic field waveform exhibits obvious high-frequency oscillation characteristics and forms a periodic amplitude modulation envelope in the time domain; the peak value of the interference magnetic field reaches 26.31 mT, and its envelope period is about 2 ms, which is consistent with the period corresponding to the 500 Hz difference frequency, indicating that the two high-frequency magnetic fields have undergone stable time-domain interference superposition in the target region.

[0114] Implementation Example 15:

[0115] This paper uses needle electrodes to measure the induced electric field at specific locations in a human brain physical model. The experimental platform is as follows: Figure 8 As shown, the distance between the two electrodes The electrode surface is coated with insulating varnish, with only about 1 mm of the tip exposed as the measurement contact point. The materials for each 100 g human brain model are as follows: 80 g water, 16.59 g corn flour, 1 g agar, 0.7 g propylene glycol, and 0.134 g sodium chloride. The conductivity of the prepared human brain model is 0.115. This is consistent with the brain gray matter conductivity at 10 kHz. By moving the probe to different positions and depths, the induced electric field at different locations on a human brain physical model was measured, and the results were... The induced electric field at that location can be obtained by converting the measurement results. The conversion formula is as follows:

[0116] (4)

[0117] The induced electric field waveforms at different locations after conversion are as follows: Figures 11-12As shown, the induced electric field exhibits a clear envelope characteristic in the target area, with significant electric field superposition and interference effects; in the non-target area, the envelope effect is weaker, mainly dominated by the high-frequency fundamental wave, and the amplitude is lower. Further analysis along the depth direction of the target area shows that the amplitude of the induced electric field decreases significantly with increasing stimulation depth. However, at a subcutaneous depth of 5 cm, the induced electric field can still reach 143 V / m, exceeding the motor threshold (100 V / m), which meets the requirements of neural modulation. This result verifies that the high-intensity temporal interferometric transcranial magnetic stimulation method proposed in this paper can effectively achieve suprathreshold intensity stimulation of deep target areas.

Claims

1. A time-domain interference pulse magnetic field generator based on parallel resonance, characterized in that: It includes two pulse magnetic field generators with the same structure, referred to as the first pulse magnetic field generator and the second pulse magnetic field generator; The first pulsed magnetic field generator includes resistors R1 and R2, diodes D1, D2, D3, D4, and D5, switches S1, S2, S3, and S4, and a power supply. Capacitor C, capacitor C1, coil 1; The first pulsed magnetic field generator includes a resistor. ,resistance ,diode ,diode ,diode ,diode ,diode ,switch ,switch ,switch ,switch ,power supply ,capacitance ,capacitance 1. Coil 2; The difference between the output frequencies of the first pulse magnetic field generator and the second pulse magnetic field generator is adjustable; By adjusting the difference in output frequency between the first and second pulse magnetic field generators, time-domain interference transcranial magnetic stimulation at different frequencies can be achieved.

2. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 1, characterized in that: The resonant unit parameters of the first pulse magnetic field generator and the second pulse magnetic field generator are different.

3. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 1, characterized in that: The switching frequencies of the first pulse magnetic field generator and the second pulse magnetic field generator are different.

4. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 1, characterized in that: The circuit topology of the first pulse magnetic field generator is shown below. power supply One end of the connector is grounded, and the other end is connected in series with a resistor R1 and a capacitor C1 before being grounded. One end of resistor R1 is connected in series with resistor R2 and then connected to a buffer circuit. Diode D5 is connected in parallel across resistor R2; Switch S1, switch S2, diode D2, switch S3, diode D3, diode D4, switch S4, and diode D1 are connected in sequence to form a series circuit; The buffer circuit is connected to coil 1.

5. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 1, characterized in that: The circuit topology of the second pulse magnetic field generator is shown below: power supply One end is grounded, and the other end is connected in series with a resistor. ,capacitance Rear grounding; One end of resistor R1 is connected in series with a resistor Then connect to the buffer circuit; diode Parallel connection in resistor Both ends; switch ,switch ,diode ,switch ,diode ,diode ,switch ,diode Connect them sequentially to form a series circuit; The buffer circuit is connected to coil 2.

6. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 1, characterized in that: The working process of the first pulse magnetic field generator and the second pulse magnetic field generator includes the charging stage, the initial discharge stage, the parallel resonance stage, and the natural decay stage.

7. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 6, characterized in that: When the first pulse magnetic field generator is in the charging phase, switches S1, S2, S3, and S4 are all in the off state, and the circuit is equivalent to a first-order RC charging circuit. Through current limiting resistor To energy storage capacitor Charge; When the second pulse magnetic field generator is in the charging phase, the switch... ,switch ,switch ,switch Both are in the off state, and the circuit is equivalent to a first-order RC charging circuit. Through current limiting resistor To energy storage capacitor Charge.

8. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 6, characterized in that: When the first pulse magnetic field generator is in the initial discharge phase, the switch... With switch Synchronous conduction, capacitor Through resistance Discharge to the LC parallel resonant module; When the second pulse magnetic field generator is in the initial discharge phase, the switch... With switch Synchronous conduction, capacitor Through resistance Discharge to the LC parallel resonant module.

9. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 6, characterized in that: When the first pulse magnetic field generator and the second pulse magnetic field generator are in the parallel resonance stage, the operating frequency of the bridge arm switch is consistent with the circuit resonant frequency.

10. The time-domain interference pulse magnetic field generator based on parallel resonance according to claim 1, characterized in that: The difference in output frequency between the first pulse magnetic field generator and the second pulse magnetic field generator is less than 1 kHz.

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