Multi-channel electrical stimulation system based on time interference electrical stimulation

Abstract

The utility model belongs to the technical field of electrical stimulation, and particularly relates to a multichannel electrical stimulation system based on time interference electrical stimulation, which uses an upper computer to search a lower computer and identify master and slave devices of the lower computer; setting a stimulation protocol on the upper computer and issuing the stimulation protocol to the lower computer; generating a clock synchronization time sequence of the stimulation protocol by using a clock chip on the master device of the lower computer, and synchronizing the clock synchronization time sequence to each slave device of the lower computer; and determining the time sequence of each stimulation waveform according to the clock synchronization time sequence by utilizing stimulation wave output components on the master equipment and the slave equipment, so as to synchronously output the stimulation waveforms to each stimulation channel. Clock synchronization ensures that all devices start and end stimulation at the same time point, so that consistency and repeatability of experiments are ensured, and accurate control of stimulation can be realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrical stimulation, and particularly relates to a multi-channel electrical stimulation system based on time-interference electrical stimulation. Background Art

[0002] Existing transcranial electrical stimulation devices generally set stimulation protocols through a host computer, and then enable each channel to independently generate waveforms through the FPGA waveform generation module and analog circuit module of the slave computer, so as to independently control each channel to achieve stimulation. However, due to the communication connection method between the host computer and the slave computer, and the hardware connection relationship of each stimulation channel in the slave computer, each stimulation channel cannot perform multi-channel electrical stimulation, especially supporting multi-person synchronous output electrical stimulation. This is also a technical problem that multi-channel electrical stimulation devices urgently need to solve.

[0003] For example, patent CN220443041U, a device for realizing transcranial electrical stimulation by using a constant current source and a dual safety system, discloses that with a main control board module as the core, the main control board module can set the stimulation mode, stimulation waveform and stimulation intensity of each channel, and uses a high-voltage integrated operational amplifier to realize the stimulation of the human body load. The minimum unit of the electromechanical stimulation module integrates 4 completely identical variable channels, each channel can be freely switched to a stimulation electrode or a common ground electrode, and each channel can adapt to the changes in different stages of the human body load and perform safety voltage limiting and current limiting separately, realizing various stimulation modes such as transcranial direct current stimulation and transcranial alternating current stimulation. The stimulation mode and stimulation intensity of each channel are controllable, and different numbers of stimulation channels can be realized by mounting different numbers of slave electromechanical stimulation modules on the main control board module.

[0004] Another example is patent CN108096703B, a multi-channel transcranial electrical stimulation device and its method, which discloses that it includes a host computer module, an ARM control module, an FPGA waveform generation module and an analog circuit module; the ARM control module is mainly responsible for the control data sent by the host computer module, and transmits the control data to the RAM storage unit of the FPGA waveform generation module through a variable static storage controller; the FPGA waveform generation module includes multiple independent channels, each channel has a waveform generation module, and each channel can independently generate waveforms, and the control data obtained by the RAM storage unit can control the generation of waveforms of each channel; it can realize that each single-channel parameter under multi-channel transcranial electrical stimulation can be adjusted, and the current feedback is increased to make the stimulation current stable. Summary of the Utility Model

[0005] The utility model provides a multi-channel electrical stimulation system based on time-interference electrical stimulation to support multi-person multi-channel synchronous time-interference electrical stimulation.

[0006] To solve the above technical problems, the present utility model provides a multi-channel electrical stimulation system based on time-interference electrical stimulation, comprising: a host computer, on which a human-computer interaction operation interface is provided for inputting a stimulation protocol; a slave computer, including a main device and at least one slave device; the host computer is communicatively connected to the slave computer to issue the stimulation protocol to the slave computer; a clock chip is provided on the main device for generating a clock synchronization timing sequence of the stimulation protocol; the main device is connected in series with the slave devices through a clock synchronization cable to synchronize the clock synchronization timing sequence to each slave device; stimulation wave output components are provided on both the main device and the slave devices to synchronously output stimulation waveforms to each stimulation channel according to the clock synchronization timing sequence.

[0007] Further, the stimulation wave output component includes: a signal generation module, a digital-to-analog conversion module, and a voltage-to-current control module; wherein the signal generation module generates a digital electrical signal of electrical stimulation according to the stimulation protocol; the digital-to-analog conversion module is used to convert the digital electrical signal into an analog electrical signal; the voltage-to-current control module is connected to the stimulation channel through a connector to convert the analog electrical signal into a constant-current electrical stimulation waveform signal by using a power supply module and output it to the stimulation channel.

[0008] Further, the digital-to-analog conversion module is configured as a multi-channel digital-to-analog conversion channel; the voltage-to-current control module includes a plurality of sub-control units; the stimulation channels correspond to the multi-channel digital-to-analog conversion channels one by one; each sub-control unit corresponds to each channel of the digital-to-analog conversion channel one by one to output corresponding constant-current electrical stimulation waveform signals to each stimulation channel.

[0009] Further, the voltage-to-current control module includes: a voltage-controlled current source functional circuit composed of a plurality of precision operational amplifiers to realize the control of the constant-current electrical stimulation intensity output by the digital-to-analog conversion module, where the voltage input V in The voltage signal output by the digital-to-analog conversion module passes through U 1 、U 2 Two precision operational amplifiers and resistors R 1 、R 2 、R 3 、R 4 、R 0 Circuit, acting on the load R L On, set the resistances of resistors R 1 、R 2 、R 3 、R 4 Are the same, and the conversion relationship is obtained as I L =V in / R 0 .

[0010] Further, the human-computer interaction operation interface includes: a display screen and a device management interface, a protocol setting interface, and a stimulation interface independently presented on the display screen; a search box is provided on the device management interface to search for and connect to the lower computer through a wireless network; a stimulation mode editing box is provided on the protocol setting interface to input the stimulation protocol; a monitoring item is provided on the stimulation interface to feedback the stimulation process.

[0011] Further, the monitoring item includes at least one of: impedance viewing, real-time impedance, issued protocol parameters, current monitoring, and stimulation process monitoring.

[0012] Further, the stimulation waveform is configured as a temporal interference electrical stimulation waveform.

[0013] The beneficial effects of the present invention are as follows. The multi-channel electrical stimulation system based on temporal interference electrical stimulation of the present invention uses the upper computer to search for the lower computer and identify the master and slave devices of the lower computer; sets the stimulation protocol on the upper computer and issues it to the lower computer; uses the clock chip on the master device of the lower computer to generate the clock synchronization timing of the stimulation protocol and synchronize it to each slave device of the lower computer; uses the stimulation wave output components on the master device and the slave devices to determine the timing of each stimulation waveform according to the clock synchronization timing, so as to synchronously output the stimulation waveforms to each stimulation channel. Clock synchronization ensures that all devices start and end stimulation at the same time point, thereby ensuring the consistency and repeatability of the experiment and enabling precise control of the stimulation.

[0014] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention are achieved and obtained by the structures specifically pointed out in the specification, claims, and drawings.

[0015] To make the above objectives, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is the principle block diagram of the multi-channel electrical stimulation system of the present invention;

[0018] Figure 2It is the principle block diagram of the tES-EEG online closed-loop regulation of the present utility model;

[0019] Figure 3 It is the principle block diagram of the stimulus wave output component of the present utility model;

[0020] Figure 4 It is the circuit diagram of the voltage-to-current control module of the present utility model. Specific embodiments

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0022] Embodiment 1

[0023] See Figures 1 - 3 , Embodiment 1 of the present invention provides a multi-channel electrical stimulation system based on time-interference electrical stimulation, including: a host computer, on which a human-computer interaction operation interface is set for inputting a stimulation protocol; a slave computer, including a main device and at least one slave device; the host computer is communicatively connected to the slave computer to issue a stimulation protocol to the slave computer; a clock chip is set on the main device for generating a clock synchronization timing sequence of the stimulation protocol; the main device is connected in series with the slave devices through a clock synchronization cable to synchronize the clock synchronization timing sequence to each slave device; a stimulus wave output component is set on both the main device and the slave devices to synchronously output stimulus waveforms to each stimulation channel according to the clock synchronization timing sequence.

[0024] Specifically, a plurality of stimulation channels can be set on both the main device and the slave devices. For example, 1 HD cable can connect 8 stimulation electrodes and 2 return electrodes, meeting the requirements of double-target area and high-precision focused stimulation. For example, this multi-channel electrical stimulation system can simultaneously use 32 channels for stimulation. See Figure 1, A multi-channel electrical stimulation system generally identifies master and slave devices by independently setting or through communication addresses, communication protocols, etc., and then sends the clock of master device 0 to slave device 1 and slave device 2, ensuring the clock synchronization timing of master and slave devices. Master device 0 sends protocols to the master device through computer 1, and at the same time supports external trigger (trigger) to control the start and stop of the master device and each slave device. The external trigger command causes the master device to start / stop stimulation, and multiple devices are connected in series through the clock synchronization cable out-IN. Clock synchronization can ensure that all devices start and end stimulation at the same time point, thus ensuring the consistency and repeatability of the experiment. For stimulations that require precise timing control, such as transcranial alternating current stimulation (tACS) to regulate intracranial rhythm synchronization, clock synchronization can improve the treatment effect, especially in adjusting the amplitude, frequency or phase coherence of brain neural oscillations.

[0025] As an alternative implementation of the input stimulation protocol.

[0026] The host computer has the function of programmable stimulation protocol, and its human-computer interaction operation interface includes: a display screen and device management interface, protocol setting interface, stimulation interface, and setting interface independently displayed on the display screen. The stimulation protocol includes 10 kinds of stimulation protocols, such as tDCS (transcranial direct current stimulation), tACS (transcranial alternating current stimulation), tPCS (transcranial pulsed electrical stimulation), tRNS (transcranial customized current stimulation), Triangle (triangle wave), Sawtooth (sawtooth wave), Transcranial Oscillatory Direct Current Stimulation, toDCS (transcranial oscillatory direct current stimulation), Amplitude Modulation (amplitude modulation wave), transcranial Custom Current Stimulation (custom waveform), temporal interference, TI (temporal interference electrical stimulation), which supports users to customize programming, break away from the conventional stimulation mode, and deeply explore individualized treatment plans. Specifically, each channel can be independently controlled by a current source. After independently programming the stimulation protocol, it controls the stimulation output, is compatible with the electroencephalograph, and can support multi-person synchronous stimulation output to meet different experimental designs and treatment requirements. Preferably, the stimulation waveform is configured as a temporal interference electrical stimulation waveform. Temporal interference (TI) stimulation technology adjusts deep brain regions through a non-invasive method. Temporal interference stimulation uses two pairs of slightly different high-frequency currents (such as 2 kHz and 2.01 kHz). Through the coherent superposition of high-frequency signals, an amplitude-modulated electric field with low-frequency and high-intensity oscillation is formed in the target area, thereby inducing nerve cell discharge. For example, the stimulation protocol for channel 1 is tACS stimulation of 1 mA\2000 Hz, and the stimulation protocol for channel 2 is tACS stimulation of 1.2 mA\2010 Hz. For in vivo experiments on mice, it shows that hippocampal neurons can be activated without activating cortical neurons being covered, and can follow the low-frequency envelope of the electric field induced by temporal interference stimulation. In addition, by changing the current input ratio of the two pairs of electrodes, the movement of the mouse's front paws, whiskers, and ears can be caused without changing the spatial position of the electrodes. Therefore, temporal interference stimulation can flexibly move the stimulation target area in the brain without moving the electrodes. The TI technology mainly solves several pain points of the current transcranial electrical stimulation technology: ①: Lack of focus ②: Limited stimulation depth ③: The selection of stimulation targets is relatively rigid and not flexible enough.

[0027] This system supports high-frequency stimulation output, meets the high-frequency stimulation output of 1000 Hz and above in TI, realizes non-invasive deep brain stimulation technology, and breaks the traditional 2-channel TI. This system can support 8-channel TI, greatly improving the freedom of setting.

[0028] Optionally, a search box is provided on the device management interface to connect and search for devices and communicate with the lower computer via Ethernet.

[0029] Optionally, a stimulation mode editing box is provided on the protocol setting interface, which allows for independent programming to input the stimulation protocol. For example, 10 stimulation modes can be set, and stimulation parameters such as current intensity, frequency, and stimulation duration can be edited, supporting device protocol duration, pseudo-stimulation mode, etc.

[0030] Optionally, monitoring items are provided on the stimulation interface to feedback the stimulation process. Among them, current and impedance are displayed in color and numerical value. For example, the monitoring items include at least one of viewing impedance, real-time impedance, sending down protocol parameters, current monitoring, and stimulation process monitoring. The upper computer has the function of real-time monitoring of the impedance status and can lock the impedance threshold to ensure the safety of the subject. This technology can ensure the detection of impedance thresholds of different individuals under different currents during transcranial electrical stimulation. The upper computer compares the detected real-time threshold of impedance with the expected threshold. When the real-time threshold is greater than the expected threshold, the system prompts "impedance exceeds the threshold" and the stimulation can be immediately interrupted; on the contrary, when the real-time threshold is less than the expected threshold, the stimulation is carried out to ensure the safety of the entire system; at the same time, the real-time system can improve the accuracy of impedance detection, so that there will be no situation where the small-current impedance detection fails to pass, improving the treatment effect and safety of the treatment process of transcranial electrical stimulation.

[0031] Optionally, selection items such as Chinese-English language switching, default protocol parameters, and double-blind mode are provided on the setting interface.

[0032] In addition, see Figure 2, since the stimulation protocol is compatible with EEG and the monitoring item has the function of feedback-stimulating process, the host computer also has the function of tES-EEG online closed-loop regulation to adjust the neural activity or its functional connection in a specific brain region, for diagnosing and improving the behavioral responses of patients with disorders of consciousness after severe brain injury. The specific steps are as follows: Step S1, edit or input the stimulation protocol on the host computer and send it to the slave computers (tES main device, each slave device); Step S2, the main device generates the clock synchronization timing sequence of the stimulation protocol and synchronizes the clock synchronization timing sequence to each slave device through the clock synchronization cable; Step S3, the stimulation wave output component outputs the stimulation waveform according to the stimulation protocol; Step S4, use the external trigger command to make the main device start / stop stimulation, and control the synchronous output of the stimulation waveforms of each stimulation channel of the main and slave devices through the clock synchronization timing sequence, and provide the current stimulation output treatment plan through the scalp; Step S5, collect the EEG signals (EEG) in real time through the acquisition electrode (or return electrode) and forward the EEG data to the host computer online; Step S6, the host computer analyzes the EEG data online to compare the real-time threshold of the impedance with the expected threshold, so as to start the closed-loop scheme, generate a new stimulation protocol and optimize the stimulation parameters; Step S7, repeat Step S1, send the new stimulation protocol to the slave computers, and output the stimulation plan on the main device and the slave devices to realize the function of the closed-loop regulated stimulation plan.

[0033] Therefore, the tES-EEG combination has the following technical advantages:

[0034] (1) Compared with the tES + scale evaluation method, the EEG-tES-EEG paradigm can continuously study the ability of brain activity. (2) For the synchronous tES-EEG system, especially using the AM-tACS stimulation mode in this system, higher spatial resolution and fewer stimulation artifacts can be obtained. (3) For the synchronous tES-EEG system, especially the tES in this system has multiple channels, and multiple regions of the brain can be stimulated by electrical stimulation (that is, using traditional single-channel electrodes or high-definition (HD) electrode placement, and evaluating its online stimulation effect through EEG to reveal the association between brain stimulation and whole-brain activity / connection). (4) The integrated EEG cap for acquisition and stimulation is adopted. By integrating the EEG acquisition electrode and the electrical stimulation electrode, the balanced potential of the acquisition electrode and the good electrochemical stability of the stimulation electrode are ensured at the same time. Through excellent structural design, it can meet the needs of sharing or real-time switching between acquisition and stimulation, omitting the process of frequently changing the electrode cap, improving the efficiency of research and treatment, and facilitating the tES-EEG closed-loop research.

[0035] As an optional implementation manner of the stimulation wave output component.

[0036] The stimulus wave output component includes: a signal generation module, a digital-to-analog conversion module, and a voltage-to-current control module. The processor of the master device or the slave device controls the signal generation module to perform independent control of individual channels in a sequential processing manner, meeting the requirement of simultaneous multi-channel output of continuous constant-current electrical stimulation and ensuring the consistency of the output waveforms of multiple channels. Specifically, see Figure 3 , the signal generation module generates a digital electrical signal for electrical stimulation according to the stimulation protocol; the digital-to-analog conversion module is used to convert the digital electrical signal into an analog electrical signal; the voltage-to-current control module is connected to the stimulation channel through a connection module (or connector), and uses the power supply module to convert the analog electrical signal into a constant-current electrical stimulation waveform signal and output it to the stimulation channel.

[0037] Optionally, the digital-to-analog conversion module includes: the digital-to-analog conversion chip model uses but is not limited to chips such as DAC8560, and a single-chip circuit can achieve 16-bit digital-to-analog conversion data output for a single channel. Preferably, the digital-to-analog conversion module is configured as a multi-channel digital-to-analog conversion channel; the voltage-to-current control module includes multiple sub-control units; the stimulation channels correspond one-to-one with the multi-channel digital-to-analog conversion channels; each sub-control unit corresponds one-to-one with each channel of the digital-to-analog conversion channel to output corresponding constant-current electrical stimulation waveform signals to each stimulation channel.

[0038] Optionally, the voltage-to-current control module includes: a voltage-controlled current source (VCCS) functional circuit composed of precision operational amplifiers, where the precision operational amplifiers use but are not limited to chips such as AD8512ARZ, accurately achieving the purpose of controlling the constant-current electrical stimulation intensity by the output of the digital-to-analog conversion module. As Figure 4 shown, V in The voltage signal output by the digital-to-analog conversion module passes through U 1 , U 2 two precision operational amplifiers and resistors R 1 , R 2 , R 3 , R 4 , R 0 circuit, and acts on the load R L . R 1 -R 4 take the same resistance value, and the conversion relationship is obtained as I L =V in / R 0 .

[0039] In the description of the embodiments of the present utility model, unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0040] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0041] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0042] Taking the above ideal embodiments of the present utility model as inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present utility model. The technical scope of the present utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A multi-channel electrical stimulation system based on time-interference electrical stimulation, characterized in that: include: A host computer, on which a human-computer interaction interface is provided for inputting stimulation protocols; A lower computer, including a master device and at least one slave device; The upper computer is connected to the lower computer for communication so as to send a stimulation protocol to the lower computer; The master device is provided with a clock chip for generating a clock synchronization timing of the stimulation protocol; The master device is connected in series with the slave devices via a clock synchronization cable to synchronize the clock synchronization timing to each slave device; The master device and the slave device are both provided with stimulation wave output components to synchronously output stimulation waveforms to each stimulation channel according to the clock synchronization sequence.

2. The multi-channel electrical stimulation system according to claim 1, characterized in that: The stimulation wave output component includes: a signal generation module, a digital-to-analog conversion module, and a voltage-to-current control module; The signal generation module generates a digital electrical signal of electrical stimulation according to the stimulation protocol; The digital-to-analog conversion module is used to convert the digital electrical signal into an analog electrical signal; The voltage-to-current control module is connected to the stimulation channel via a connector, so as to utilize a power supply module to convert the analog electrical signal into a constant current electrical stimulation waveform signal and output it to the stimulation channel.

3. The multi-channel electrical stimulation system according to claim 2, characterized in that: The digital-to-analog conversion module is configured as multiple digital-to-analog conversion channels; The voltage-to-current control module includes a plurality of sub-control units; The stimulation channels correspond one-to-one to the multiple digital-to-analog conversion channels; Each sub-control unit corresponds one-to-one to each digital-to-analog conversion channel to output a corresponding constant current electrical stimulation waveform signal to each stimulation channel.

4. The multi-channel electrical stimulation system according to claim 2, characterized in that: The voltage-to-current control module includes: a voltage-controlled current source functional circuit composed of multiple precision operational amplifiers to achieve constant current electrical stimulation intensity controlled by the output of the digital-to-analog conversion module, wherein the voltage input V in The voltage signal output by the digital-to-analog conversion module passes through the two precision op amps U1 and U2 and the resistors R1, R2, R3, R4, and R0 circuits, and then acts on the load R L The resistance values ​​of resistors R1, R2, R3, and R4 are set to be the same, and the conversion relationship is I L =V in / R0.

5. The multi-channel electrical stimulation system according to claim 1, characterized in that: The human-computer interaction operation interface includes: a display screen and a device management interface, a protocol setting interface, and a stimulation interface independently displayed on the display screen; The device management interface is provided with a search box to search and connect to the lower computer via a wireless network; The protocol setting interface is provided with a stimulation mode editing box for inputting the stimulation protocol; The stimulation interface is provided with monitoring items to provide feedback on the stimulation process.

6. The multi-channel electrical stimulation system according to claim 5, characterized in that: The monitoring items include: checking impedance, real-time impedance, sending protocol parameters, current monitoring, and at least one of stimulation process monitoring.

7. The multi-channel electrical stimulation system according to claim 1, characterized in that: The stimulation waveform is configured as a time-interferometric electrical stimulation waveform.

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