EEG-based brain electrical stimulation measurement and control circuit, measurement and control all-in-one machine and measurement and control method

Abstract

The EEG-based brain electrical stimulation measurement and control circuit, the measurement and control all-in-one machine and the measurement and control method in the embodiment of the invention comprise a multi-channel EEG pickup circuit, a multi-channel constant current source circuit and a signal switching circuit, the multi-channel EEG pick-up circuit and the multi-channel constant current source circuit are connected with a plurality of electrode links working in a parallel mode through the signal switching circuit; the signal switching circuit realizes parallel connection with a plurality of electrode links through a built-in multi-channel analog switch matrix; when the input level value received by the multi-channel analog switch matrix is a first level, the electrode link is conducted with the multi-channel EEG pickup circuit; and when the input level value received by the multi-channel analog switch matrix is a second level, the electrode link is conducted with the multi-channel constant current source circuit, so that integrated operation and management of EEG data acquisition and electroencephalogram stimulation application of a subject can be realized, the working efficiency is effectively improved, and the system is suitable for the technical field of medical care.

Description

Technical Field

[0001] This application relates to the technical field of medical care, and particularly relates to an EEG-based brain electrical stimulation measurement and control circuit, a measurement and control integrated machine, and a measurement and control method. Background Art

[0002] Transcranial Direct Current Stimulation (abbreviated as tDCS) is one of the neuromodulation technologies that has received much attention in recent years in the fields of cerebrovascular diseases, mental diseases, etc. It consists of two surface electrodes, an anode and a cathode, and a controller. When in use, after the electrodes are placed on the brain surface, the controller outputs by setting the stimulation type, and acts on the cerebral cortex with a weak polarized direct current. Different from other non-invasive brain stimulation technologies, such as Transcranial electrical stimulation (abbreviated as tES) and Transcranial Magnetic Stimulation (abbreviated as TMS), tDCS does not cause neuronal discharge through supra-threshold stimulation, but exerts its effect by regulating the activity of the cerebral cortex neural network.

[0003] At the neuronal level, the basic mechanism of tDCS regulating the excitability of the cerebral cortex is to cause changes in the resting membrane potential hyperpolarization or depolarization according to the different polarities of the stimulation. The polarization of the tDCS membrane involves the influence of current on the neuronal membrane potential, which is the main mechanism of the immediate action after tDCS stimulation. Specifically: Anodic current reduces the membrane potential, making neurons more likely to reach the action potential threshold, thus enhancing nerve activity; Cathodic current increases the membrane potential, making neurons more difficult to reach the action potential threshold, thus inhibiting nerve activity; Therefore, anodic stimulation usually depolarizes neurons and increases excitability, while cathodic stimulation hyperpolarizes neurons and reduces excitability.

[0004] Traditional electroencephalogram (abbreviated as EEG) and traditional non-invasive brain stimulation technologies (such as tES) are usually used separately; the electroencephalograph only extracts, collects, transmits, and analyzes EEG signals, and conducts various clinical EEG signal examinations through a configured electrode cap (such as wet electrodes, saline electrodes) to complete the recording of brain electrical activities; while tES only applies direct current stimulation and alternating current stimulation to the skin according to a prescription through configured stimulation electrodes of different sizes to regulate brain activities; the two types of devices cannot work simultaneously, and the signals cannot be fused.

[0005] In scientific research and clinical practice, the demand for combining EEG monitoring and non-invasive brain stimulation technology intervention is increasing day by day. This combination can monitor the brain's response in real time and adjust the stimulation parameters according to the feedback to improve the accuracy and effect of treatment or experiment.

[0006] However, in the prior art, there is often a lack of integrated devices that can manage these two technologies simultaneously. In addition, the tDCS devices in the prior art are single-channel stimulations, without realizing multi-source radiation stimulation and multi-point convergence stimulation, making it difficult to simulate the communication of neural networks, and without realizing the synchronous recording of EEG and TRIG, resulting in complex operations and low efficiency. Summary of the Invention

[0007] To solve one of the above technical defects, the embodiments of the present application provide an EEG-based electroencephalic stimulation measurement and control circuit, a measurement and control integrated machine, and a measurement and control method, which can realize the integrated operation and management of the acquisition of EEG data of a subject and the application of electroencephalic stimulation, and can effectively improve work efficiency.

[0008] In the first aspect of the embodiments of the present application, an EEG-based electroencephalic stimulation measurement and control circuit is provided, including: a multi-channel EEG pickup circuit, a multi-channel constant current source circuit, and a signal switching circuit;

[0009] Both the multi-channel EEG pickup circuit and the multi-channel constant current source circuit are connected to a plurality of electrode links operating in parallel through the signal switching circuit;

[0010] The signal switching circuit realizes parallel connection with a plurality of electrode links through a built-in multi-channel analog switch matrix;

[0011] When the input level value received by the multi-channel analog switch matrix is the first level, the electrode link is conducted with the multi-channel EEG pickup circuit;

[0012] When the input level value received by the multi-channel analog switch matrix is the second level, the electrode link is conducted with the multi-channel constant current source circuit.

[0013] In an optional embodiment of the present application, each of the electrode links can output or receive current. When the sum of the input and output currents of a plurality of electrode links is zero, the plurality of electrode links can perform homologous star radiation stimulation and multi-source multi-path homologous stimulation on the skin.

[0014] In an optional embodiment of the present application, the multi-channel constant current source circuit includes: a multi-channel constant current source generator and a first control unit;

[0015] The multi-channel constant current source generator includes: a plurality of voltage-controlled source circuits; each of the voltage-controlled source circuits is connected to a plurality of voltage-controlled constant current source circuits operating in parallel;

[0016] The output ends of the plurality of voltage-controlled constant current source circuits are connected to the plurality of electrode links through the multi-channel analog switch matrix in a one-to-one correspondence;

[0017] The voltage-controlled source circuit realizes the output of DC, AC, random or arbitrary waveform data according to the parameter setting of the first control unit, and drives the operation of the voltage-controlled constant current source circuit.

[0018] In an optional embodiment of the present application, the multi-channel constant current source circuit further includes: a multi-channel current and contact impedance detection circuit;

[0019] The multi-channel current and contact impedance detection circuit includes: a plurality of current detection circuits;

[0020] The number of the current detection circuits is the same as that of the voltage-controlled constant current source circuits, and each of the current detection circuits is respectively arranged on the output link of the voltage-controlled constant current source circuit;

[0021] When the current value on the corresponding voltage-controlled constant current source circuit acquired by the current detection circuit exceeds the preset value, the electrode link connected to the corresponding voltage-controlled constant current source circuit is turned off.

[0022] In an optional embodiment of the present application, an impedance detection unit is arranged on the current detection circuit; the impedance detection unit detects the contact impedance value between the electrode and the skin, and when the contact impedance value is less than the preset value, it indicates that the electrode has fallen off.

[0023] In an optional embodiment of the present application, the multi-channel EEG pickup circuit includes: the second control unit, and the second control unit is connected to a plurality of electroencephalogram signal acquisition circuits in parallel;

[0024] The input ends of the plurality of electroencephalogram signal acquisition circuits are respectively connected to the plurality of electrode links through a multi-channel analog switch matrix;

[0025] After receiving the acquisition start and stop signals of the second control unit, the electroencephalogram signal acquisition circuit conducts or disconnects the connection with the electrode link.

[0026] In an optional embodiment of the present application, the first level is the low level in the PWM level signal, and the second level is the high level in the PWM level signal.

[0027] In the second aspect of the embodiments of the present application, there is provided an EEG-based electroencephalic stimulation measurement and control integrated machine, including: a human-computer interaction device and an electroencephalic stimulation measurement and control circuit; the human-computer interaction device and the electroencephalic stimulation measurement and control circuit are communicatively connected;

[0028] The electroencephalic stimulation measurement and control circuit is the EEG-based electroencephalic stimulation measurement and control circuit as described above.

[0029] In an optional embodiment of the present application, an isolation circuit is arranged between the human-computer interaction device and the electroencephalic stimulation measurement and control circuit.

[0030] In an optional embodiment of the present application, the human-computer interaction device includes: a main controller and a data transmission circuit; the main controller is connected to a peripheral device through the data transmission circuit.

[0031] In a third aspect of the embodiments of the present application, a method for measuring and controlling EEG-based brain electrical stimulation is provided, including the EEG-based brain electrical stimulation measurement and control circuit as described above;

[0032] The method includes the following steps:

[0033] Obtain the pre-stimulation EEG acquisition task parameters, stimulation task parameters, and post-stimulation EEG acquisition task parameters corresponding to the treatment plan;

[0034] Generate an input level sequence of a multi-channel analog switch matrix according to the pre-stimulation EEG acquisition task parameters, stimulation task parameters, and post-stimulation EEG acquisition task parameters;

[0035] The signal switching circuit automatically switches the conduction between the multi-channel EEG pickup circuit and the multi-channel constant current source circuit and the electrode link according to the input level sequence through the built-in multi-channel analog switch matrix, and completes EEG signal acquisition and brain electrical stimulation output.

[0036] Adopting the technical solution provided in the embodiments of the present application, compared with the prior art:

[0037] 1. In the embodiments of the present application, by making the electrode link conduct with the multi-channel EEG pickup circuit or the electrode link conduct with the multi-channel constant current source circuit through the signal switching circuit, the on-demand switching of the stimulation function and the EEG pickup function can be realized, so that during the process of picking up EEG signals, stimulation is simultaneously implemented, which not only reduces the signal interference and inaccurate data problems brought by the alternating operation process of the two functions and improves work efficiency; but also enables the operator to monitor the reaction of the brain in real time and adjust the stimulation parameters according to the feedback parameters of the EEG pickup function, improving the accuracy of treatment or experiment.

[0038] 2. In the embodiments of the present application, each electrode link can output or receive current. When the sum of the input and output currents of multiple electrode links is zero, the multiple electrode links can perform homogenous star radiation stimulation and multi-source multi-path homogenous stimulation on the skin, and realize networked mutual stimulation between the left and right halves by simulating the communication mode between neural networks.

[0039] Other features and advantages of the present application will be described in the subsequent specification, and part of them will become obvious from the specification, or be understood by implementing the present application. The purpose and other advantages of the present application can be achieved and obtained through the content pointed out in the written specification and the drawings. Description of the Drawings

[0040] The accompanying drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0041] Figure 1 FIG. is a schematic structural diagram of an EEG-based brain electrical stimulation measurement and control circuit provided by an embodiment of the present application;

[0042] Figure 2 FIG. is a circuit schematic diagram of a channel analog switch matrix provided by an embodiment of the present application;

[0043] Figure 3 FIG. is a schematic structural diagram of a multi-channel constant current source circuit in an EEG-based brain electrical stimulation measurement and control circuit provided by an embodiment of the present application;

[0044] Figure 4 FIG. is a circuit schematic diagram of a multi-channel constant current source generator in an embodiment of the present application;

[0045] Figure 5 FIG. is a circuit schematic diagram of a current detection circuit in an embodiment of the present application;

[0046] Figure 6 FIG. is a circuit schematic diagram of electrode contact DC impedance detection in an embodiment of the present application;

[0047] Figure 7 FIG. is a circuit schematic diagram of electrode contact AC impedance detection in an embodiment of the present application;

[0048] Figure 8 FIG. is a schematic structural diagram of a multi-channel EEG pickup circuit in an EEG-based brain electrical stimulation measurement and control circuit provided by an embodiment of the present application;

[0049] Figure 9 FIG. is a circuit schematic diagram of a second control unit and an electroencephalogram signal acquisition circuit in an embodiment of the present application;

[0050] Figure 10 FIG. is a schematic network structure diagram of an EEG-based brain electrical stimulation measurement and control all-in-one machine in an embodiment of the present application;

[0051] Figure 11 FIG. is a schematic flow diagram of an EEG-based brain electrical stimulation measurement and control method provided by an embodiment of the present application;

[0052] In the figures:

[0053] 10 is a brain electrical stimulation measurement and control circuit, 20 is a human-computer interaction device, and 30 is an isolation circuit;

[0054] 101 is a multi-channel EEG pickup circuit, 102 is a multi-channel constant current source circuit, 103 is a signal switching circuit, and 104 is an electrode link;

[0055] 1011 is a second control unit, and 1012 is an electroencephalogram signal acquisition circuit;

[0056] 1021 is a first control unit, 1022 is a multi-channel constant current source generator, and 1023 is a multi-channel current and contact impedance detection circuit;

[0057] 10221 is a voltage-controlled source circuit, and 10222 is a voltage-controlled constant current source circuit;

[0058] 301 is a high-speed magnetic isolation circuit, and 302 is an isolated power supply. Specific implementation mode

[0059] In the following elaboration, in order to ensure the accuracy of citation and the fluency of reading, the key technical terms, abbreviations or acronyms involved in the text are summarized and explained as follows:

[0060] EEG, electroencephalogram, electroencephalogram;

[0061] tES, Transcranial electrical stimulation, transcranial stimulation;

[0062] tDCS, Transcranial Direct Current Stimulation, transcranial direct current stimulation;

[0063] tACS, Transcranial alternating Current Stimulation, transcranial alternating current stimulation;

[0064] tRNS, Transcranial random noise stimulation, transcranial random noise stimulation;

[0065] TMS, Transcranial Magnetic Stimulation, transcranial magnetic stimulation;

[0066] Sham, sham stimulation;

[0067] ADC, Analog-to-digital converter, analog-to-digital converter;

[0068] RS232, Electronic Industries Association (EIA) Standard - RS - 232, the RS - 232 communication interface standard formulated by the Electronic Industries Association.

[0069] In the process of implementing this application, the inventors found that electroencephalogram (EEG), as a commonly used neuro - function detection technology, can record the electrical activities of neurons, can non - invasively record the instantaneous brain activities of the entire cerebral cortex, and has the advantage of high temporal resolution; when in use, the electrodes on the EEG electrode cap are in close contact with the scalp through media such as conductive paste or physiological saline to sense the EEG signals, and then are transmitted through wires to an electroencephalograph for amplification, filtering, digitization, etc., and finally converted into an electroencephalogram waveform diagram for doctors to analyze and diagnose.

[0070] In the existing field, during the detection and treatment of mental diseases for subjects, traditional electroencephalic stimulation devices mostly adopt fixed stimulation methods and parameters, applying direct - current stimulation and alternating - current stimulation to the skin through stimulation to regulate brain activities; for the brain activities before and after diagnosis and treatment, an electroencephalograph has to be used separately for recording and analysis, which is inconvenient and cumbersome to operate.

[0071] In view of the above problems, an EEG - based electroencephalic stimulation measurement and control circuit is provided in the embodiments of this application.

[0072] In order to make the technical solutions and advantages in the embodiments of this application clearer and more understandable, the following further elaborates on the exemplary embodiments of this application with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0073] As Figure 1 shown, exemplarily, the EEG - based electroencephalic stimulation measurement and control circuit includes: a multi - channel EEG pickup circuit 101, a multi - channel constant - current source circuit 102, and a signal switching circuit 103;

[0074] Both the multi - channel EEG pickup circuit 101 and the multi - channel constant - current source circuit 102 are connected to a plurality of electrode links 104 operating in parallel through the signal switching circuit 103;

[0075] The signal switching circuit 103 realizes parallel connection with a plurality of electrode links 104 through an internal multi - channel analog switch matrix;

[0076] When the input level value received by the multi - channel analog switch matrix is the first level, the electrode link 104 is conducted with the multi - channel EEG pickup circuit 101;

[0077] When the input level value received by the multi-channel analog switch matrix is the second level, the electrode link 104 is turned on to the multi-channel constant current source circuit 102.

[0078] Based on the above solution, in the present application, the signal switching circuit 103 enables the electrode link 104 to be turned on to the multi-channel EEG pickup circuit 101, or the electrode link 104 to be turned on to the multi-channel constant current source circuit 102, which can realize the on-demand switching between the stimulation function and the EEG pickup function, so that during the process of picking up EEG signals, stimulation (which may include: multi-source stimulation and homologous radiation stimulation) can be implemented simultaneously, not only reducing the problems of signal interference and inaccurate data during the alternating operation of the two functions and improving work efficiency; but also enabling the operator to monitor the brain's response in real time and adjust the stimulation parameters according to the feedback parameters of the EEG pickup function, thereby improving the accuracy of treatment or experiments.

[0079] In the embodiments of the present application, the input level value received by the multi-channel analog switch matrix can be set according to specific application scenarios and device deployments. For example, it can come from the control modules of the multi-channel EEG pickup circuit 101 and / or the multi-channel constant current source circuit 102; or it can come from an external control device, such as the human-computer interaction device described in another embodiment of the present application.

[0080] In an optional embodiment of the present application, each electrode link 104 can output or receive current. When the sum of the input and output currents of multiple electrode links 104 is zero, the multiple electrode links 104 can perform homologous star radiation stimulation and multi-source multi-path homologous stimulation on the skin, and realize networked mutual stimulation between the left and right halves by simulating the communication mode between neural networks.

[0081] Specifically, when the electrode links 104 are used in pairs, one electrode value of each pair of electrode links 104 is positive and the other is negative, and the sum of the input and output currents of each pair of electrode links 104 is zero; then, the multiple electrode links 104 can perform homologous star radiation stimulation on the skin;

[0082] When the electrode links 104 are used in groups of multiple electrodes, one electrode link 104 in each group of electrode links 104 is negative, and the other several electrode links 104 are sub-positive, and the sum of the input and output currents of the multiple sub-positives and the negative is zero; then, the multiple electrode links 104 can perform multi-source multi-path homologous stimulation on the skin.

[0083] As Figure 2 shown, in an optional embodiment of the present application, the multi-channel analog switch matrix of the signal switching circuit 103 can be composed of multiple analog switches of model ADG1434 connected in series, and can be selected through the I2C bus-controlled IO expansion port.

[0084] Since the signal-to-noise ratio of EEG signals is poor, the amplitude is low, and generally at the μV level, while the maximum stimulation current is 4 mA. When the stimulation impedance is 4 K, the amplitude is as high as 16 V. The signal difference between the EEG signal and the stimulation current is more than 160,000 times (100 dB). Therefore, in this application, analog switches with small on-resistance and high channel-to-channel crosstalk isolation are used to isolate the EEG signal and the stimulation current to prevent signal interference.

[0085] Specifically, the first level can be the low level in the PWM level signal, and the second level can be the high level in the PWM level signal. When the input of a certain analog switch in the multi-channel analog switch matrix is at a low level, it switches to the EEG channel, and when the input of the analog switch is at a high level, it switches to the stimulation channel.

[0086] The electrode link 104 in the embodiment of this application can be applied to scenarios with both stimulation functions and EEG pickup functions. Before use, the pre-stimulation EEG acquisition task, stimulation task, and post-stimulation EEG acquisition task can be set according to the treatment plan. During use, the stimulation function or EEG pickup function is automatically switched according to the corresponding task. Compared with the traditional method, it reduces the electrode plugging and unplugging between the two function switches, simplifies the operation process, and avoids the EEG fluctuation interference caused during the plugging and unplugging process.

[0087] In the embodiment of this application, in the scenario of the EEG pickup function, the total number of channels of the multi-channel EEG pickup circuit 101 can be 40. In the scenario of the stimulation function, the total number of channels of the multi-channel constant current source circuit 102 can be 20.

[0088] As Figure 3 shown, the multi-channel constant current source circuit 102 includes: a multi-channel constant current source generator 1022 and a first control unit 1021;

[0089] The multi-channel constant current source generator 1022 includes: a plurality of voltage-controlled source circuits 10221; each of the voltage-controlled source circuits 10221 is connected to a plurality of voltage-controlled constant current source circuits 10222 operating in parallel;

[0090] The output ends of the plurality of voltage-controlled constant current source circuits 10222 are connected to the plurality of electrode links 104 through the multi-channel analog switch matrix in a one-to-one correspondence;

[0091] The voltage-controlled source circuit 10221 realizes the output of DC, AC, random or arbitrary waveform data according to the parameter setting of the first control unit 1021, and drives the voltage-controlled constant current source circuit 10222 to operate.

[0092] In this embodiment, the stimulation modes of the stimulation channels formed by the multi-channel constant current source circuit 102 and the electrode link 1021 can be divided into four types:

[0093] Direct current stimulation (implemented by tDCS and capable of intensity adjustment);

[0094] Pulse stimulation (implemented by tACS and capable of adjusting intensity, frequency, and phase);

[0095] White noise stimulation (implemented by tRNS and capable of intensity adjustment);

[0096] Sham stimulation (in this mode, the stimulation time can be adjusted).

[0097] Specifically, each of the electrode links 104 can output or receive current; when used as a stimulation channel, each channel (here referring to an electrode link 104) can apply only one stimulation mode, or three stimulation modes simultaneously, and can be used in combination with sham stimulation.

[0098] However, the sum of the intensities of the three stimulation methods (tDCS, tACS, tRNS) cannot be greater than 2000 μA.

[0099] When used as a stimulation channel, it must be ensured that the intensities can cancel each other out, that is, the sum is 0.

[0100] In the embodiment of the present application, the voltage-controlled source circuit (10221) can be composed of 3 16-bit digital-to-analog converters AD5668ARUZ-2 to achieve the output of DC, AC, random, and arbitrary waveform data, and drive the voltage-controlled constant current source circuit (10222); since each digital-to-analog converter AD5668ARUZ-2 has 8 channels, each digital-to-analog converter AD5668ARUZ-2 can be connected to a maximum of 8 voltage-controlled constant current source circuits (10222).

[0101] The voltage-controlled constant current source circuit (10222) can be composed of 20 dual instrumentation amplifiers AD8426 and 5 quad operational amplifiers AD8624; the dual instrumentation amplifier and the quad operational amplifier form a 2 mA-level voltage-controlled constant current source circuit.

[0102] In the embodiment of the present application, the digital-to-analog converter AD5668ARUZ-2 outputs a stimulation waveform signal of 0 to 2.5 V, which is input to the positive terminal of the instrumentation amplifier AD8426, raising the level of the negative terminal of the instrumentation amplifier AD8426 by 1.25 V, changing the range to ±1.25 V, and the sampling resistor can be set to 500 ohms. Therefore:

[0103] Constant current range: ±1.25 V / 500 Ω = ±2.5 mA, that is, -2.5 mA to 2.5 mA;

[0104] The current resolution is: 5 mA / 65535 = 76 nA.

[0105] During the hardware implementation of the multi-channel constant current source circuit 102: One quad operational amplifier AD8624 and four dual instrumentation amplifiers AD8426 form a group of 4-channel voltage-controlled constant current source circuits; therefore, five quad operational amplifiers AD8624 and twenty dual instrumentation amplifiers AD8426 together form five groups of 4-channel voltage-controlled constant current source circuits, and the outputs of the twenty dual instrumentation amplifiers correspond to the 20 outputs of the voltage-controlled constant current source circuits.

[0106] The connection between the voltage-controlled source circuit (10221) and the voltage-controlled constant current source circuit (10222) can be as follows:

[0107] The first digital-to-analog converter AD5668ARUZ-2 is connected to two groups of 4-channel voltage-controlled constant current source circuits;

[0108] The second digital-to-analog converter AD5668ARUZ-2 is connected to two groups of 4-channel voltage-controlled constant current source circuits;

[0109] The third digital-to-analog converter AD5668ARUZ-2 is connected to one group of 4-channel voltage-controlled constant current source circuits.

[0110] As an example, the circuit schematic of the first digital-to-analog converter AD5668ARUZ-2 connected to two groups of 4-channel voltage-controlled constant current source circuits is as Figure 4 shown.

[0111] In the embodiment of the present application, the multi-channel constant current source circuit 102 further includes: a multi-channel current and contact impedance detection circuit 1023;

[0112] The multi-channel current and contact impedance detection circuit 1023 includes: multiple current detection circuits;

[0113] The number of the current detection circuits is the same as the number of the voltage-controlled constant current source circuits 10222, and each of the current detection circuits is respectively arranged on the output link of the voltage-controlled constant current source circuit 10222;

[0114] When the current value on the corresponding voltage-controlled constant current source circuit 10222 obtained by the current detection circuit exceeds a preset value, the electrode link 104 connected to the corresponding voltage-controlled constant current source circuit 10222 is turned off.

[0115] In the embodiment of the present application, in order to ensure the safe current output of transcranial stimulation, a current detection chip is placed at the output position of the voltage-controlled constant current source circuit 10222, and this current detection chip can detect the voltage drop on the current sensing resistor in the common-mode voltage range from -0.2V to +26V independent of the power supply voltage.

[0116] The model of the current detection chip can be AD8426. The current detection chip integrates a matched resistor gain network with four fixed gain device options, and this integrated matched resistor gain network can minimize the gain error and reduce the temperature drift. In this embodiment, the current detection chip with the model of AD8426 is powered by a power supply from -15V to +15V, and the maximum power supply current consumed is 260 μA.

[0117] Specifically, in circuit implementation, the detection resistor Rsense can be connected in series to the output of the voltage-controlled constant current source circuit 10222, and the output of the current detection chip with the model of AD8426 is connected to the controller through the ADC module. When a ±5 mA current passes through the detection resistor Rsense (10 ohms), a ±50 mV voltage is generated. Since the amplification factor of the current detection chip with the model of AD8426 is 25 times, the output voltage of the current detection chip with the model of AD8426 is ±1.25V. The ADC resolution is 16 bits, and the resolution is 2.5V / 65535 = 0.04 mV, and the current measurement accuracy reaches 0.15 μA, which can meet the requirements of output current amplitude detection.

[0118] To improve the detection accuracy, the detection resistor Rsense can be a resistor with an accuracy of 0.1% and a temperature coefficient of 25 ppm / °C.

[0119] During the real-time detection by the controller, when it is found that the output current exceeds 5 mA, the stimulation current is immediately turned off and the indicator light flashes for warning to protect the subject. When the detection resistor Rsense is short-circuited, open-circuited, or the current detection chip fails, the voltage detected by the controller will be within a fixed value range. At this time, if the stimulation mode is in the pulse mode (tACS), it can be determined that the detection circuit has a fault.

[0120] Among them, the controller can be the first control unit in the embodiment of the present application or a human-computer interaction device.

[0121] In the embodiment of the present application, the circuit schematic diagram of the current detection circuit is as Figure 5 shown, Figure 5 where IL is the output of the upper-level constant current source circuit, and J is connected to the electrode link.

[0122] In the embodiment of the present application, an impedance detection unit is provided on the current detection circuit;

[0123] The impedance detection unit detects the contact impedance value between the electrode and the skin. When the contact impedance value is less than the preset value, it indicates that the electrode has fallen off.

[0124] In the embodiment of the present application, the impedance detection unit can include: electrode contact DC impedance detection and electrode contact AC impedance detection.

[0125] As shown Figure 6 in the circuit for detecting the DC impedance of the electrode contact: when the gain resistor Rg is not used, the default setting of the current detection chip (model: AD8426) is that the current amplification factor G = 1;

[0126] Constant current = (V_DA - 1.25V) / R sampling1;

[0127] I = 1.25 / 560 = ±2.232mA;

[0128] I_S_OUT = 10Ω * I * 50 times + 1.25V = 1.25V ± 1.116V = 0.134V to 2.336V

[0129] V_OUT = (V_STIM + 22 * 1.25V) / 23;

[0130] Among them, 22 = 220K / 10K; 23 = (220K + 10K) / 10K, and 560 is the resistance value of the sampling resistor.

[0131] As shown Figure 7 in the detection principle of the impedance detection unit is:

[0132] Establish a resistance model Rx of the lead CH (electrode link) relative to the reference Ref, an impedance model Rch relative to the ground, and an impedance model Rref of the reference Ref relative to the ground; among them, the lead CH is any lead; finally, the measured voltage signal is the voltage difference relative to the reference Ref. Therefore, Rx reflects the impedance characteristics between the lead and the reference.

[0133] A stimulation current of 200nA is injected into all electrodes of the head, including the reference electrode; then, the actual injected current is 200nA. All lead currents return to the signal ground through the ground electrode. Relative to the reference electrode, the current injected into the lead CH is divided into Ix and Ich, that is, Ich0 = Ix + Ich. The internal impedance of the head is discrete and the distribution is relatively complex. Measuring Rx is relatively complex. Considering that the voltage generated by the reference current is a common-mode signal, then simplifying the schematic diagram and considering Rref as 0 and Rch as Rx, we get:

[0134]

[0135] U xd is U x -U ref , Rh = 100MΩ, Ug = 4.5V;

[0136]

[0137] Since U g << Uxd ,

[0138] Calculation method:

[0139] After data acquisition, calculate U x -U ref =U xd , and obtain the waveform of U xd . There are DC and signals other than 30Hz in the acquired signal. After passing through a 28 - 32Hz digital band - pass filter (9 - order IIR Butterworth), calculate U xd The mean - square value of the signal within 1s, substitute it into U xd / 200nA, and calculate to obtain.

[0140] As Figure 8 shown, in the embodiment of the present application, the multi - channel EEG pickup circuit 101 includes: a second control unit 1011, and the second control unit 1011 is connected to a plurality of electroencephalogram signal acquisition circuits 1012 in parallel;

[0141] The input ends of multiple electroencephalogram signal acquisition circuits 1012 are respectively connected to multiple electrode links 104 through a multi - channel analog switch matrix; after receiving the acquisition start and stop signals of the second control unit, the electroencephalogram signal acquisition circuit 1012 conducts or cuts off the EEG electrode link 1011.

[0142] As Figure 9 shown, in the embodiment of the present application, the electroencephalogram signal acquisition circuit 1012 may include: 5 pieces of 8 - channel ADS1299 chips; the ADS1299 chip has 8 independent 24 - bit high - resolution analog - to - digital converters. The second control unit 1011 configures parameters such as the acquisition channels, sampling rate, and amplification factor of 5 pieces of ADS1299 chips through the SCLK and MOSI ports at the same time; the second control unit 101 drives 5 pieces of ADS1299 chips to collect simultaneously through the START signal.

[0143] In the embodiment of the present application, electroencephalogram has the advantages of being safe, non - invasive, inexpensive, and easy to carry. Moreover, the high time resolution of electroencephalogram enables it to capture the rapid dynamics of brain activities, making electroencephalogram not as sluggish as other brain monitoring methods (such as fMRI) and capable of quickly evaluating the effects of different stimuli; therefore, during transcranial stimulation, recording electroencephalogram is very important for the development of brain electrical stimulation.

[0144] An embodiment of the present application also provides an EEG - based brain electrical stimulation measurement and control integrated machine.

[0145] As Figure 10As shown, exemplarily, an EEG-based brain electrical stimulation measurement and control integrated machine includes: a human-computer interaction device 20 and a brain electrical stimulation measurement and control circuit 10;

[0146] The human-computer interaction device 20 and the brain electrical stimulation measurement and control circuit 10 are communicatively connected;

[0147] The brain electrical stimulation measurement and control circuit 10 is the EEG-based brain electrical stimulation measurement and control circuit as described above.

[0148] In an embodiment of the present application, a graphical interface can be used through the human-computer interaction device 20 to facilitate the user to set stimulation parameters and start / stop stimulation; and the current stimulation parameters and device status can be displayed, such as: current intensity, stimulation time, electrode connection status, etc.; data during the stimulation process can also be recorded for subsequent analysis and evaluation of the treatment effect.

[0149] In an embodiment of the present application, an isolation circuit 30 is provided between the human-computer interaction device 20 and the brain electrical stimulation measurement and control circuit 10.

[0150] Specifically, the isolation circuit 30 includes: a high-speed magnetic isolation circuit 301 and an isolation power supply 302; the high-speed magnetic isolation circuit 301 can isolate the human-computer interaction device 20 and the brain electrical stimulation measurement and control circuit 10 by using a magnetic field to achieve the effects of isolation, protection, and noise reduction.

[0151] In an embodiment of the present application, the human-computer interaction device 20 includes: a main controller 201 and a data transmission circuit 202; the main controller 201 is connected to a peripheral device through the data transmission circuit.

[0152] For the specific limitations of the above-mentioned brain electrical stimulation measurement and control circuit, reference can be made to the limitations in the above text, and details will not be repeated here.

[0153] Each module in the above-mentioned EEG-based brain electrical stimulation measurement and control circuit and the EEG-based brain electrical stimulation measurement and control integrated machine can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or stored in the memory in the computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules.

[0154] An embodiment of the present application also provides an EEG-based brain electrical stimulation measurement and control method.

[0155] As Figure 11 shown, exemplarily, an EEG-based brain electrical stimulation measurement and control method includes the above-mentioned EEG-based brain electrical stimulation measurement and control circuit;

[0156] The method includes the following steps:

[0157] Obtain the pre - stimulation EEG acquisition task parameters, stimulation task parameters, and post - stimulation EEG acquisition task parameters corresponding to the treatment plan;

[0158] Generate an input level sequence of the multi - channel analog switch matrix according to the pre - stimulation EEG acquisition task parameters, stimulation task parameters, and post - stimulation EEG acquisition task parameters;

[0159] The signal switching circuit automatically switches the conduction of the multi - channel EEG pickup circuit and the multi - channel constant - current source circuit with the electrode link according to the input level sequence through the built - in multi - channel analog switch matrix, and completes EEG signal acquisition and electroencephalogram stimulation output.

[0160] In the embodiments of the present application, the stimulation task parameters include: stimulation intensity, frequency, waveform, and stimulation time.

[0161] Generally, when detecting and treating a subject, the following several stages may be included:

[0162] First, the preparation stage:

[0163] First, conduct equipment inspection to check whether all components involved in the method are properly connected, including: electrode wires, stimulation output wires, etc., to ensure no looseness or damage;

[0164] Second, turn on the device power supply and check whether the device can be started normally and whether each functional module passes the self - test;

[0165] Third, electrode preparation, select a suitable EEG electrode cap and stimulation electrodes according to needs, and prepare the conductive paste conductive medium

[0166] After that, prepare the subject, explain the operation process and precautions to the subject, eliminate the subject's nervousness, obtain the subject's cooperation, let the subject wash their hair, keep the scalp clean and dry to reduce the scalp resistance, improve the quality of electroencephalogram signal acquisition, and help the subject sit or lie comfortably on the examination bed and adjust the body position.

[0167] Second, the operation stage:

[0168] First, place the electrodes, correctly wear the EEG electrode cap on the subject's head to ensure that the electrodes are in close contact with the scalp; apply an appropriate amount of conductive paste between the electrodes and the scalp to reduce the contact resistance and ensure that the electrodes are firmly connected;

[0169] Second, perform parameter settings. According to the specific situation of the subject and the treatment plan corresponding to the examination purpose, set the EEG acquisition task parameters, such as: sampling frequency, filtering range, gain, etc.; at the same time, according to the stimulation task parameters, set the parameters of transcranial electrical stimulation, including stimulation intensity, frequency, waveform, stimulation time, etc.;

[0170] Next, after confirming that the parameter settings are correct, start collecting electroencephalogram (EEG) signals; and through the real-time display of EEG waveforms, check the signal quality to ensure there is no obvious interference and artifacts.

[0171] (If necessary, adjust the electrode position or reapply the conductive medium to optimize the signal acquisition effect. During the acquisition process, ask the subject to remain quiet and relaxed, and avoid large movements or behaviors that may cause interference such as blinking or grinding teeth.)

[0172] After the EEG signal acquisition is stable, apply transcranial electrical stimulation to the subject's brain according to the set protocol; during the stimulation process, closely observe the subject's reaction and ask the subject if there are any discomfort symptoms. If there are obvious discomforts such as headache, dizziness, or scalp tingling, immediately stop the stimulation and adjust the stimulation parameters.

[0173] During the above process, data recording and monitoring are carried out, automatically recording the EEG signals and the current and voltage data of tDCS stimulation, including: EEG waveforms, stimulation current, stimulation waveforms, real-time parameters of stimulation voltage, etc., enabling the operator to view and analyze the data in real time and observe the changes in EEG signals before and after tDCS stimulation.

[0174] The EEG stimulation measurement and control method based on EEG provided by the embodiments of this application can improve the work efficiency of the operator when applied in this stage.

[0175] Third, the end stage.

[0176] First, after completing the EEG acquisition and stimulation tasks scheduled in the treatment plan, first stop the stimulation output, and then stop the EEG signal acquisition;

[0177] Second, carefully remove the electrode cap from the subject's head, wipe the residual substances such as conductive paste on the subject's scalp with clean water or a special cleaning agent to keep the scalp clean; and clean and disinfect the electrodes for future use.

[0178] Third, save the collected data to a computer or other storage devices, and perform necessary sorting and backup. According to needs, the data can be further analyzed and processed, such as filtering, denoising, feature extraction, etc.

[0179] Adopting the solution provided by this application can simultaneously implement multi-source stimulation and homologous radiation-type stimulation during the EEG signal extraction process, enabling rapid research on the EEG change rules before and after stimulation and the time effect after stimulation, providing a real-time, accurate, and synchronous tool for brain science research, and can be widely applied in fields such as medical health management and medical research.

[0180] For example, through the technical solution provided by the present application, it is possible to collect in real time the response signals of the subject's brain to electrical stimulation, which facilitates the operator to more comprehensively grasp the electrophysiological state of the brain, improve the accuracy of diagnosis, and provide a more accurate basis for subsequent surgical treatment and the like.

[0181] For another example, through the technical solution provided by the present application, by using the electroencephalogram activity data of the subject, the stimulation parameters such as intensity, frequency, etc. are adjusted to achieve personalized neuromodulation treatment, improve the treatment effect, and reduce side effects.

[0182] For another example, through the technical solution provided by the present application, by continuously monitoring the changes in the electroencephalogram signals, it is convenient for the operator to evaluate the tES treatment effect and timely adjust the treatment plan.

[0183] For another example, through the technical solution provided by the present application, by using EEG to record the electroactivity changes of this brain region and related brain networks, it can help researchers deeply explore the neural mechanisms of the brain, understand the neural information transmission and processing mechanisms during processes such as perception, memory, and learning of the brain; and by applying different modes of tES stimulation and observing the changes in brain neural activities reflected by EEG signals, researchers can understand how the connections and functions between neurons in the brain change after being stimulated, providing theoretical support for neural rehabilitation and treatment.

[0184] It should be understood that although each step in the flowchart is displayed sequentially according to the indication of the arrow, these steps do not necessarily execute sequentially in the order indicated by the arrow. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the figure may include multiple sub-steps or multiple stages. These sub-steps or stages do not necessarily execute at the same moment, but can execute at different moments. The execution order of these sub-steps or stages is not necessarily sequential either, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0185] In one embodiment, a computer device is provided. The computer device includes a processor, a memory, a network interface, and a database connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, it implements the above EEG-based brain electrical stimulation measurement and control method. It includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, it implements any step in the above EEG-based brain electrical stimulation measurement and control method.

[0186] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it can implement any step in the above EEG-based brain electrical stimulation measurement and control method.

[0187] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a device, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0188] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the function specified in Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0189] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the function in the process Figure 1One or more processes and / or blocks Figure 1 The functions specified in one or more blocks.

[0190] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 One or more processes and / or blocks Figure 1 The steps of the functions specified in one or more blocks.

[0191] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0192] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. An EEG-based brain electrical stimulation measurement and control circuit, characterized in that: include: A multi-channel EEG pickup circuit (101), a multi-channel constant current source circuit (102) and a signal switching circuit (103); The multi-channel EEG pickup circuit (101) and the multi-channel constant current source circuit (102) are connected to a plurality of electrode links (104) operating in parallel via a signal switching circuit (103); The signal switching circuit (103) realizes parallel connection with multiple electrode links (104) through a built-in multi-channel analog switch matrix; When the input level value received by the multi-channel analog switch matrix is ​​a first level, the electrode link (104) is connected to the multi-channel EEG pickup circuit (101); When the input level value received by the multi-channel analog switch matrix is ​​a second level, the electrode link (104) is connected to the multi-channel constant current source circuit (102).

2. The EEG-based brain electrical stimulation measurement and control circuit according to claim 1, characterized in that: Each of the electrode links (104) can output or receive current, and when the sum of the input and output currents of the multiple electrode links (104) is zero, the multiple electrode links (104) can perform homologous star-shaped radiation stimulation and multi-source multi-path homologous stimulation on the skin.

3. The EEG-based brain electrical stimulation measurement and control circuit according to claim 1, characterized in that: The multi-channel constant current source circuit (102) comprises: a multi-channel constant current source generator (1022) and a first control unit (1021); The multi-channel constant current source generator (1022) comprises: a plurality of voltage-controlled source circuits (10221); each of the voltage-controlled source circuits (10221) is connected to a plurality of voltage-controlled constant current source circuits (10222) operating in parallel; The output ends of the plurality of voltage-controlled constant current source circuits (10222) are connected to the plurality of electrode links (104) in a one-to-one correspondence via a multi-channel analog switch matrix; The voltage-controlled source circuit (10221) realizes the output of direct current, alternating current, random or arbitrary waveform data according to the parameter setting of the first control unit (1021), and drives the voltage-controlled constant current source circuit (10222) to operate.

4. The EEG-based brain electrical stimulation measurement and control circuit according to claim 3, characterized in that: The multi-channel constant current source circuit (102) further comprises: a multi-channel current and contact impedance detection circuit (1023); The multi-channel current and contact impedance detection circuit (1023) comprises: a plurality of current detection circuits; The number of the current detection circuits is consistent with the number of the voltage-controlled constant current source circuits (10222), and each of the current detection circuits is respectively arranged on an output link of the voltage-controlled constant current source circuit (10222); When the current value on the corresponding voltage-controlled constant current source circuit (10222) obtained by the current detection circuit exceeds a preset value, the electrode link (104) connected to the corresponding voltage-controlled constant current source circuit (10222) is turned off.

5. The EEG-based brain electrical stimulation measurement and control circuit according to claim 4, characterized in that: The current detection circuit is provided with an impedance detection unit; The impedance detection unit detects the contact impedance value of the electrode-skin. When the contact impedance value is less than a preset value, it indicates that the electrode has fallen off.

6. The EEG-based brain electrical stimulation measurement and control circuit according to claim 1, characterized in that: The multi-channel EEG pickup circuit (101) comprises: a second control unit (1011), the second control unit (1011) being connected to a plurality of electroencephalogram signal acquisition circuits (1012) in parallel; The input ends of the plurality of electroencephalogram signal acquisition circuits (1012) are connected to the plurality of electrode links (104) in a one-to-one correspondence via a multi-channel analog switch matrix; After receiving the acquisition start and stop signal from the second control unit, the electroencephalogram signal acquisition circuit (1012) turns on or off the connection with the electrode link (104).

7. The EEG-based brain electrical stimulation measurement and control circuit according to claim 1, characterized in that: The first level is a low level in the PWM level signal, and the second level is a high level in the PWM level signal.

8. An EEG-based brain electrical stimulation measurement and control integrated machine, characterized in that: include: A human-computer interaction device (20) and a brain electrical stimulation measurement and control circuit (10); The human-machine interaction device (20) is communicatively connected to the brain electrical stimulation measurement and control circuit (10); The electroencephalogram stimulation measurement and control circuit (10) is an EEG-based electroencephalogram stimulation measurement and control circuit as claimed in any one of claims 1 to 7.

9. The EEG-based brain electrical stimulation measurement and control integrated machine according to claim 8, characterized in that: An isolation circuit (30) is provided between the human-machine interaction device (20) and the brain electrical stimulation measurement and control circuit (10).

10. An EEG-based method for measuring and controlling brain electrical stimulation, characterized in that: It comprises the EEG-based brain electrical stimulation measurement and control circuit as described in any one of claims 1 to 7; The method comprises the following steps: Obtaining pre-stimulation EEG acquisition task parameters, stimulation task parameters, and post-stimulation EEG acquisition task parameters corresponding to the treatment plan; generating an input level sequence of a multi-channel analog switch matrix according to pre-stimulus EEG acquisition task parameters, stimulation task parameters, and post-stimulus EEG acquisition task parameters; The signal switching circuit automatically switches the conduction between the multi-channel EEG pickup circuit and the multi-channel constant current source circuit and the electrode link according to the input level sequence through the built-in multi-channel analog switch matrix, thereby completing EEG signal acquisition and EEG stimulation output.

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