Electroencephalogram Detection Device, Impedance Detection Method, and Storage Medium

Abstract

The present invention discloses an electroencephalogram detection device, an impedance detection method, and a storage medium. The electroencephalogram detection device includes an impedance network, a switch circuit unit, an analog processing unit, an analog-to-digital conversion unit, and a digital processing unit. The signal output end of the impedance network is electrically connected to the signal input end of the analog processing unit, the driven end of the impedance network is electrically connected to the driving end of the analog processing unit, the signal output end of the analog processing unit is electrically connected to the signal input end of the analog-to-digital conversion unit, the signal output end of the analog-to-digital conversion unit is connected to the signal input end of the digital processing unit, the switch circuit unit is connected in series between the signal output end of the impedance network and the signal input end of the analog processing unit, and the controlled end of the switch circuit unit is electrically connected to the control end of the digital processing unit. Through the present application, the results of the acquisition and processing of electroencephalogram signals can be ensured to be stable and reliable.

Description

Technical Field

[0001] The present invention relates to an electroencephalogram (EEG) detection device for detecting EEG signals in the medical field, and particularly to an EEG detection device, an impedance detection method, and a storage medium. Background Art

[0002] Living human tissue cells always generate very weak bioelectricity. EEG signals are the overall effects of the electrical activities of a large number of brain nerve cells in a highly coherent state on the cerebral cortex. By using electrodes placed on the scalp, the electrical activities of brain cells are led out and amplified by an EEG detection device for analysis and recording. It contains certain waveforms, amplitudes, frequencies, and phases and is variable, which is the analysis of electroencephalogram. When the brain tissue undergoes functional changes, this waveform curve will change accordingly, thus providing a basis for clinical diagnosis and treatment.

[0003] Since EEG signals are very weak themselves, various external factors during the measurement process will inevitably cause artifacts and noise that affect the quality of EEG signals. Interference caused by poor contact between electrodes and the scalp, power frequency interference, and amplifier channel noise are the three most influential interference sources in EEG detection. Some traditional EEG detection devices do not have the function of monitoring the electrode connection status, and some can only partially measure the connection status of lead electrodes and cannot measure all lead electrodes. Summary of the Invention

[0004] The present invention provides an EEG detection device, an impedance detection method, and a storage medium, aiming to solve the technical problem of unstable processing results of EEG signals.

[0005] To achieve the above object, the present invention provides an EEG detection device, which includes an impedance network, a switch circuit unit, an analog processing unit, an analog-to-digital conversion unit, and a digital processing unit; the signal output end of the impedance network is electrically connected to the signal input end of the analog processing unit, the driven end of the impedance network is electrically connected to the driving end of the analog processing unit, the signal output end of the analog processing unit is electrically connected to the signal input end of the analog-to-digital conversion unit, the signal output end of the analog-to-digital conversion unit is connected to the signal input end of the digital processing unit, the switch circuit unit is connected in series between the signal output end of the impedance network and the signal input end of the analog processing unit, and the controlled end of the switch circuit unit is electrically connected to the control end of the digital processing unit.

[0006] Further, the EEG detection device further includes an auxiliary circuit unit, and the auxiliary circuit unit is connected in series between the impedance network and the switch circuit unit.

[0007] Optionally, the EEG detection device further includes a power supply module, and the power supply module includes:

[0008] A positive power supply, which is a constant current source, is connected to the switching circuit unit;

[0009] A negative power supply, which is a constant current source, is connected to the switching circuit unit.

[0010] Further, the digital processing unit includes:

[0011] A switch control sub-unit, which is electrically connected to the controlled end of the switching circuit unit;

[0012] An impedance detection sub-unit, which is electrically connected to the signal output end of the analog-to-digital conversion unit and includes a test signal filter and an impedance calculator connected to each other;

[0013] An electroencephalogram (EEG) signal processing sub-unit, which is electrically connected to the signal output end of the analog-to-digital conversion unit and includes an EEG signal filter and an EEG signal processor connected to each other.

[0014] Specifically, the analog processing unit includes a filter amplification circuit and a driving circuit. The signal input end of the filter amplification circuit is connected to the signal input end of the impedance network, the signal output end of the filter amplification circuit is connected to the signal input end of the analog-to-digital conversion unit, and the driving end of the driving circuit is connected to the driven end of the impedance network.

[0015] Specifically, the impedance network includes at least two EEG signal test electrodes, an impedance test auxiliary electrode, and a driving auxiliary electrode. The EEG signal test electrodes are respectively connected to the signal input end of the filter amplification circuit, the impedance test auxiliary electrode is connected to the signal input end of the filter amplification circuit, and the driving auxiliary electrode is connected to the driving end of the driving circuit.

[0016] Further, the switching circuit unit includes at least two groups of signal test switches. The switching circuit unit includes at least two groups of signal test switches and a first switch. The signal test switches correspond to the EEG signal test electrodes one by one. The signal test switches include a first signal test switch and a second signal test switch. One end of the first signal test switch is connected to the signal output end of the EEG signal test electrode, the signal input end of the filter amplification circuit, and the node of the second signal test switch. The other end of the first signal test switch is connected to the positive power supply; One end of the second signal test switch is connected to the signal output end of the EEG signal test electrode, the signal input end of the filter amplification circuit, and the node of the first signal test switch. The other end of the second signal test switch is connected to the node of the driving end of the driving circuit and the driven end of the impedance network. One end of the first switch is connected to the negative power supply, and the other end of the first switch is connected to the signal input end of the filter amplification circuit.

[0017] To achieve the above object, the present application also provides a method for detecting the impedance of an electroencephalogram (EEG) detection device. The steps of the method for detecting the impedance of the EEG detection device include:

[0018] Obtain a control instruction, and select the working mode of the EEG detection device according to the control instruction;

[0019] If the EEG acquisition mode is selected, acquire an EEG signal, and generate an EEG signal processing result according to the EEG signal;

[0020] If the impedance detection mode is selected, obtain a power supply test signal, generate an impedance detection signal according to the power supply test signal, and obtain a theoretical contact impedance based on the impedance detection signal.

[0021] Optionally, obtain the current amplitude of the current source and the circuit amplification gain;

[0022] Calculate the theoretical contact impedance according to the current amplitude, the circuit amplification gain, and the impedance detection signal.

[0023] To achieve the above object, the present application also provides a storage medium, on which an impedance detection program for an EEG detection device is stored. When the impedance detection program for the EEG detection device is executed by a processor, the EEG detection device is implemented.

[0024] In the present application, an EEG detection device is provided. Since the EEG detection device includes an impedance network, a switch circuit unit, an analog processing unit, an analog-to-digital conversion unit, and a digital processing unit that are interconnected, the EEG detection device can complete the processing of EEG signals and the detection of the internal impedance of the device, thereby ensuring the stability and reliability of the results of the acquisition and processing of EEG signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0026] Figure 1 It is a schematic diagram of the module structure of an EEG detection device according to an embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the module structure of an EEG detection device according to another embodiment of the present invention;

[0028] Figure 3 It is a schematic diagram of the module structure of an EEG detection device according to still another embodiment of the present invention;

[0029] Figure 4 Schematic diagram of the module structure of the electroencephalogram detection device according to still another embodiment of the present invention;

[0030] Figure 5 Flowchart of the impedance detection method of the electroencephalogram detection device according to an embodiment of the present invention;

[0031] Figure 6 Schematic circuit diagram of the electroencephalogram detection device according to an embodiment of the present invention.

[0032] Explanation of the reference numerals in the drawings:

[0033]

[0034] The realization of the object of the present invention, functional features and advantages will be further described in conjunction with the embodiments with reference to the drawings. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0037] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0038] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; 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 or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] Based on the above hardware structure, various embodiments of the method of the present invention are proposed.

[0041] Living human body tissue cells always generate very weak bioelectricity. Electroencephalogram (EEG) signals are the overall effects of the electrical activities of a large number of brain nerve cells in a highly coherent state on the cerebral cortex. The electrical activities of brain cells are led out by electrodes placed on the scalp and amplified by EEG detection equipment for analysis and recording. It has a certain waveform, amplitude, frequency, and phase and is variable, which is the EEG analysis. When the brain tissue undergoes functional changes, this waveform curve will change accordingly, thus providing a basis for clinical diagnosis and treatment.

[0042] Since the EEG signal itself is very weak, various external factors will inevitably cause artifacts and noise during the measurement process, which affect the quality of the EEG signal. The interference caused by poor contact between the electrode and the scalp, power frequency interference, and amplifier channel noise are the three most influential interference sources in EEG detection. Some traditional EEG detection devices do not have the function of monitoring the connection status of electrodes, and some can only partially measure the connection status of lead electrodes and cannot measure all lead electrodes.

[0043] To solve the above problems, the present application proposes an EEG detection device, referring to Figure 2, in the first embodiment of the electroencephalogram (EEG) detection device of the present invention, the EEG detection device includes: an impedance network 1, a switch circuit unit 2, an analog processing unit 3, an analog-to-digital conversion unit 4, and a digital processing unit 5; the signal output end of the impedance network 1 is electrically connected to the signal input end of the analog processing unit 3, the driven end of the impedance network 1 is electrically connected to the driving end of the analog processing unit 3, the signal output end of the analog processing unit is electrically connected to the signal input end of the analog-to-digital conversion unit 4, the signal output end of the analog-to-digital conversion unit 4 is connected to the signal input end of the digital processing unit 5, the switch circuit unit 2 is connected in series between the signal output end of the impedance network 1 and the signal input end of the analog processing unit 3, and the controlled end of the switch circuit unit 2 is electrically connected to the control end of the digital processing unit 5.

[0044] In this embodiment, the EEG detection device includes: an impedance network 1, a switch circuit unit 2, an analog processing unit 3, an analog-to-digital conversion unit 4, and a digital processing unit 5. Among them, the impedance network 1 includes at least four lead electrodes, which are used to be placed on the scalp to collect the EEG signals of brain cells. The EEG signal is the overall effect of the electrical activities of a large number of brain nerve cells in a highly coherent state on the cerebral cortex.

[0045] The signal output end of the impedance network 1 is electrically connected to the signal input end of the analog processing unit 3. After the impedance network 1 collects the EEG signal, the EEG signal is transmitted to the analog processing unit 3. The analog processing unit 3 is used to perform processing such as filtering and amplifying the EEG signal; in addition, the driving end of the analog processing unit 3 is connected to the driven end of the impedance network 1, which is used to maintain the traceability of the EEG signal.

[0046] The signal output end of the analog processing unit is electrically connected to the signal input end of the analog-to-digital conversion unit 4. After the EEG signal is filtered and amplified, it enters the analog-to-digital conversion unit 4, and the analog-to-digital conversion unit 4 performs digital quantization and coding on the EEG signal. In one embodiment, the analog processing unit is a plurality of identical triodes.

[0047] The signal output end of the analog-to-digital conversion unit 4 is also connected to the signal input end of the digital processing unit 5. The analog-to-digital conversion unit 4 inputs the EEG signal after digital quantization and coding into the digital processing unit 5. The digital processing unit 5 can perform signal processing on the EEG signal to obtain the waveform of the electroencephalogram. In one embodiment, the analog-to-digital conversion unit 4 is an AD converter.

[0048] In addition, the switch circuit unit 2 is connected in series between the signal output end of the impedance network 1 and the signal input end of the analog processing unit 3, and is used to control the start and stop of the EEG signal detection process.

[0049] The present application provides an electroencephalogram (EEG) detection device. The EEG detection device includes an impedance network 1, a switch circuit unit 2, an analog processing unit 3, an analog-to-digital conversion unit 4, and a digital processing unit 5 that are interconnected. Through the above EEG detection device, the processing of EEG signals and the detection of the internal impedance of the device can be completed, thereby ensuring the stability and reliability of the results of the acquisition and processing of EEG signals.

[0050] In one embodiment, the EEG detection device further includes an auxiliary circuit unit 6, and the auxiliary circuit unit 6 is connected in series between the impedance network 1 and the switch circuit unit 2.

[0051] In this embodiment, the auxiliary circuit unit 6 is connected in series between the impedance network 1 and the switch circuit unit 2. Before the impedance network 1 transmits the acquired EEG signal to the switch circuit unit 2, the EEG signal will first be transmitted to the auxiliary circuit unit 6. The auxiliary circuit unit 6 is used for defibrillation and ESD defibrillation, that is, to limit the harmful large signals in the EEG signal, and then transmit the EEG signal to the switch circuit unit 2.

[0052] In one embodiment, the EEG detection device further includes a power supply module 7, and the power supply module 7 includes:

[0053] A positive power supply 71, the positive power supply 71 is a constant current source and is connected to the switch circuit unit 2;

[0054] A negative power supply 72, the negative power supply 72 is a constant current source and is connected to the switch circuit unit 2.

[0055] The EEG detection device further includes a power supply module 7. In this embodiment, the power supply module 7 includes a positive power supply 71 and a negative power supply 72. Both the positive power supply 71 and the negative power supply 72 are constant current sources, and the positive power supply 71 and the negative power supply 72 are respectively connected to the switch circuit unit 2. Specifically, the positive power supply 71 and the negative power supply 72 are two symmetric constant current sources. The fundamental frequency of the constant current source is not limited, and it is not limited to alternating current or direct current, sine wave or square wave, whether it is within or outside the EEG signal band, and it must be within the passband of the 3 analog processing unit 3. Since there are two symmetric current sources in the present application, the working mode is push-pull.

[0056] In addition, there are two working modes in the EEG detection device of the present application. In the EEG acquisition mode, the current source does not work. In addition to the EEG acquisition mode for acquiring and processing EEG signals, there is also an impedance test mode for testing the impedance of the lead electrodes in the impedance network 1. In the impedance test mode, the positive power supply 71 and the negative power supply 72 generate a power test signal. The power test signal can form a closed loop at the scalp through the impedance network 1 to generate an impedance test signal. The impedance test signal sequentially passes through the analog processing unit 3 and the analog-to-digital conversion unit 4 to reach the digital processing unit 5. The digital processing unit 5 can calculate the theoretical contact impedance of each lead electrode according to the impedance test signal.

[0057] In one embodiment, the digital processing unit 5 includes:

[0058] A switch control sub-unit 51, electrically connected to the controlled end of the switch circuit unit 2;

[0059] An impedance detection sub-unit 52, electrically connected to the signal output end of the analog-to-digital conversion unit 4, including a test signal filter and an impedance calculator connected to each other;

[0060] An EEG signal processing sub-unit 53, electrically connected to the signal output end of the analog-to-digital conversion unit 4, including an EEG signal filter and an EEG signal processor connected to each other.

[0061] In this embodiment, the digital processing unit 5 respectively includes a switch control sub-unit 51, an impedance detection sub-unit 52, and an EEG signal processing sub-unit 53. Among them, the control end of the switch control sub-unit 51 is electrically connected to the controlled end of the switch circuit unit 2, and is used to control the opening and closing of each switch in the switch circuit unit 2; the signal input end of the impedance detection sub-unit 52 is electrically connected to the signal output end of the analog-to-digital conversion unit 4, and is used to receive the impedance test signal output by the analog-to-digital conversion unit 4, filter out the EEG signal through the test signal filter, and then calculate the theoretical contact impedance of each lead electrode through the impedance calculator.

[0062] The EEG signal processing sub-unit 53 is electrically connected to the signal output end of the analog-to-digital conversion unit 4, and is used to receive the EEG signal output by the analog-to-digital conversion unit 4, filter out the impedance test signal through the EEG signal filter, and then perform final processing on the EEG signal through the EEG signal processor.

[0063] In one embodiment, the analog processing unit 3 includes a filter amplification circuit 31 and a driving circuit 32. The signal input end of the filter amplification circuit 31 is connected to the signal input end of the impedance network 1, the signal output end of the filter amplification circuit 31 is connected to the signal input end of the analog-to-digital conversion unit 4, and the driving end of the driving circuit 32 is connected to the driven end of the impedance network 1.

[0064] In this embodiment, the analog processing unit 3 includes a filter amplification circuit 31 and a drive circuit 32. The signal input end of the filter amplification circuit 31 is connected to the signal output end of the impedance network 1, and the signal output end of the filter amplification circuit 31 is connected to the signal input end of the analog-to-digital conversion unit 4, which is used to filter and amplify the impedance test signal and the electroencephalogram signal. The drive end of the drive circuit 32 is connected to the driven end of the impedance network 1. Whether in the electroencephalogram acquisition mode or the impedance test mode, the drive circuit 32 can extract the slow-changing wave in the electroencephalogram signal, and pass the slow-changing wave through the impedance module to reach the user's scalp, and negatively feedback to the scalp to cancel the static voltage fluctuation on the scalp, so as to compress the dynamic range of the electroencephalogram signal to match the signal input range of the analog processing unit 3, so as to maintain the traceability of the electroencephalogram signal.

[0065] In one embodiment, the impedance network 1 includes at least two electroencephalogram signal test electrodes Z1-Zn, an impedance test auxiliary electrode Zref, and a drive auxiliary electrode Zgnd. The electroencephalogram signal test electrodes Z1-Zn are respectively connected to the signal input end of the filter amplification circuit 31, the impedance test auxiliary electrode Zref is connected to the signal input end of the filter amplification circuit 31, and the drive auxiliary electrode Zgnd is connected to the drive end of the drive circuit 32.

[0066] In this embodiment, the impedance network 1 includes at least two electroencephalogram signal test electrodes Z1-Zn, at least one impedance test auxiliary electrode Zref, and at least one drive auxiliary electrode Zgnd. The electroencephalogram signal test electrodes Z1-Zn are respectively connected to the signal input end of the filter amplification circuit 31, the impedance test auxiliary electrode Zref is connected to the signal input end of the filter amplification circuit 31, and the drive auxiliary electrode Zgnd is connected to the drive end of the drive circuit 32. Among them, the electroencephalogram signal test electrodes Z1-Zn are used to collect electroencephalogram signals, the impedance test auxiliary electrode Zref is used to perform impedance tests, and the drive auxiliary electrode Zgnd is used to assist the drive circuit 32 to maintain the traceability of the electroencephalogram signal.

[0067] In one embodiment, the switch circuit unit 2 includes at least two groups of signal test switches S1 - Sn. The switch circuit unit 2 includes at least two groups of signal test switches S1 - Sn and a first switch S0. The signal test switches S1 - Sn correspond one-to-one with the electroencephalogram signal test electrodes Z1 - Zn. The signal test switches S1 - Sn include a first signal test switch S1S1 - Sn and a second signal test switch S2S1 - Sn. One end of the first signal test switch S1S1 - Sn is connected to the signal output end of the electroencephalogram signal test electrodes Z1 - Zn, the signal input end of the filter amplification circuit 31, and the node of the second signal test switch S2S1 - Sn. The other end of the first signal test switch S1S1 - Sn is connected to the positive power supply 71. One end of the second signal test switch S2S1 - Sn is connected to the signal output end of the electroencephalogram signal test electrodes Z1 - Zn, the signal input end of the filter amplification circuit 31, and the node of the first signal test switch S1S1 - Sn. The other end of the second signal test switch S2S1 - Sn is connected to the node of the driving end of the driving circuit 32 and the driven end of the impedance network 1. One end of the first switch S0 is connected to the negative power supply 72, and the other end of the first switch S0 is connected to the signal input end of the filter amplification circuit 31.

[0068] In this embodiment, as Figure 6 shown, the switch circuit unit 2 includes at least two groups of signal test switches S1 - Sn. Each group of signal test switches S1 - Sn includes two, and each group of signal test switches S1 - Sn corresponds one-to-one with an electroencephalogram signal test electrode Z1 - Zn. Specifically, each signal test switch S1 - Sn can control whether the power test signal passes through the impedance network 1 and forms a closed loop at the scalp to generate an impedance test signal.

[0069] Furthermore, the filter amplification circuit 31 includes at least three operational amplifiers, including two electroencephalogram signal test operational amplifiers and one driving auxiliary operational amplifier. The electroencephalogram signal test electrodes Z1 - Zn correspond one-to-one with the electroencephalogram signal test operational amplifiers, and the driving auxiliary electrode Zgnd corresponds to the driving auxiliary operational amplifier. Specifically, each electroencephalogram signal test electrode Z1 - Zn is connected to the non-inverting input terminal of its corresponding electroencephalogram signal test operational amplifier, the driving auxiliary electrode Zgnd is connected to the non-inverting input terminal of the driving auxiliary operational amplifier, and the impedance test auxiliary electrode Zref is connected to the inverting input terminals of all operational amplifiers.

[0070] The present invention also proposes an impedance detection method for an electroencephalogram detection device. The steps of the impedance detection method for the electroencephalogram detection device include:

[0071] Step S100, obtain a control instruction, and select an operating mode of the electroencephalogram (EEG) detection device according to the control instruction;

[0072] Step S200, if the EEG acquisition mode is selected, acquire an EEG signal, and generate an EEG signal processing result according to the EEG signal;

[0073] Step S300, if the impedance detection mode is selected, obtain a power supply test signal, generate an impedance detection signal according to the power supply test signal, and obtain a theoretical contact impedance based on the impedance detection signal.

[0074] There are two operating modes in the EEG detection device of the present application. One operating mode is the EEG acquisition mode for acquiring and processing EEG signals, and the other operating mode is the impedance test mode for testing the impedance of the lead electrodes in the impedance network 1.

[0075] In the EEG acquisition mode, at least two EEG signal test electrodes Z1-Zn in the impedance network 1 are placed on the user's scalp, and the EEG signals on the human scalp are respectively acquired. Moreover, the EEG signals can reach the switch circuit unit 2 and the auxiliary circuit unit 6 simultaneously. In the EEG acquisition mode, all the switches in the switch circuit unit 2 are disconnected. Therefore, the power supply module 7 will not affect the EEG acquisition. The auxiliary circuit unit 6 restricts the harmful large signals in the EEG signals, and then the EEG signals enter the analog processing unit 3. The analog processing unit 3 filters and amplifies the EEG signals. The amplified EEG signals enter the analog-to-digital conversion unit 4 to be converted from analog signals to digital signals. The converted EEG signals enter the digital processing unit 5 to obtain an EEG signal processing result. Among them, the EEG signal processing result can be an electroencephalogram in the form of a curve graph or a record in the form of text.

[0076] In the impedance test mode, the positive power supply 71 and the negative power supply 72 respectively generate a power supply test signal. Among them, the power supply test signal includes a positive power supply 71 test signal and a negative power supply 72 test signal. The positive power supply 71 generates a positive power supply 71 test signal, and the negative power supply 72 generates a negative power supply 72 test signal. As Figure 6 shown, in the impedance test mode, the switch S0 is closed, and the switches S1-Sn in the switch circuit unit 2 are alternately closed for a first preset duration and then disconnected to alternately test the theoretical contact impedance of each EEG signal test electrode Z1-Zn in the impedance network 1. Among them, the first preset duration is a time length set in advance by those skilled in the art. In this way, the power supply test signal passes through the impedance network 1 and will form a closed loop at the scalp to generate an impedance test signal for the analog processing unit 3. The analog processing unit 3 will also filter and amplify the impedance test signal. Then the impedance test signal passes through the analog-to-digital conversion unit 4 to reach the digital processing unit 5, and the digital processing unit 5 can calculate the theoretical contact impedance of each lead electrode according to the impedance test signal.

[0077] In one embodiment, the step of obtaining the theoretical contact impedance based on the impedance detection signal includes:

[0078] Obtain the current amplitude of the current source and the circuit amplification gain;

[0079] Calculate the theoretical contact impedance according to the current amplitude, the circuit amplification gain, and the impedance detection signal.

[0080] In this embodiment, taking Figure 6 as an example, since both the positive power supply 71 and the negative power supply 72 are constant current sources, the current amplitude of the constant current source can be set as I, and the amplitudes of the impedance detection signals received in the digital processing unit 5 can be U1, U2......U n-1 , U n , U 1g , U 2g .

[0081] Among them, U 1g is the signal amplitude of the impedance detection signal passing through the CH1 channel after the switch S1 is closed; U 2g is the signal amplitude of the impedance detection signal passing through the CH2 channel after the switch S2 is closed. Then the following equations can be listed:

[0082]

[0083] Among them, Z1, Z2, Z3.......Z n , Z ref , Z gnd are the theoretical contact impedances corresponding to each lead electrode respectively. g is the circuit amplification gain of the analog processing unit 3. When I, g, U1, U2......U n-1 , U n , U 1g , U 2g are all known quantities, the theoretical contact impedances of each lead electrode can be calculated. Based on the above calculation method, this application supports the contact impedance test for the zero electrode, and this application supports the impedance test for the lead electrodes of the fully differential circuit.

[0084] The present invention also proposes an impedance detection device for an electroencephalogram detection device. The impedance detection device for an electroencephalogram detection device includes a memory, a processor, and an impedance detection program for an electroencephalogram detection device stored on the memory and executable on the processor. The impedance detection program for an electroencephalogram detection device is used to execute the methods described in various embodiments of the present invention.

[0085] The present invention also provides a storage medium, on which an impedance detection program of an electroencephalogram detection device is stored. The storage medium includes a computer-readable storage medium, and the computer-readable storage medium can be Figure 1 a memory in the, or at least one of ROM (Read-Only Memory), RAM (Random Access Memory), magnetic disk, and optical disc. The storage medium includes several instructions for causing an Internet of Things terminal device having a processor (which may be a mobile phone, a computer, a server, an Internet of Things terminal, or a network device, etc.) to execute the methods described in various embodiments of the present invention.

[0086] In the present invention, the terms "first", "second", "third", "fourth", and "fifth" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0087] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in multiple embodiments or examples of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0088] Although the embodiments of the present invention have been shown and described above, the scope of protection of the present invention is not limited thereto. It can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, and substitutions to the above embodiments within the scope of the present invention, and these changes, modifications, and substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be subject to the scope of protection of the claims.

Claims

1. An electroencephalogram detection device, characterized in that, The electroencephalogram (EEG) detection device includes an impedance network, a switch circuit unit, an analog processing unit, an analog-to-digital conversion unit, and a digital processing unit; the signal output terminal of the impedance network is electrically connected to the signal input terminal of the analog processing unit, the driven terminal of the impedance network is electrically connected to the driving terminal of the analog processing unit, the signal output terminal of the analog processing unit is electrically connected to the signal input terminal of the analog-to-digital conversion unit, the signal output terminal of the analog-to-digital conversion unit is connected to the signal input terminal of the digital processing unit, the switch circuit unit is connected in series between the signal output terminal of the impedance network and the signal input terminal of the analog processing unit, and the controlled terminal of the switch circuit unit is electrically connected to the control terminal of the digital processing unit; The driving terminal is used to generate a negative feedback signal according to the slow-changing wave of the driven terminal, and adjust the output signal range of the impedance network through the negative feedback signal to match the input signal range of the driving terminal; The EEG detection device further includes a power supply module, and the power supply module includes a positive power supply, which is a constant current source and is connected to the switch circuit unit; a negative power supply, which is a constant current source and is connected to the switch circuit unit.

2. The electroencephalogram detection device according to claim 1, wherein, The EEG detection device further includes an auxiliary circuit unit, and the auxiliary circuit unit is connected in series between the impedance network and the switch circuit unit.

3. The electroencephalogram detection device according to claim 2, characterized in that, The digital processing unit includes: A switch control sub-unit, which is electrically connected to the controlled terminal of the switch circuit unit; An impedance detection sub-unit, which is electrically connected to the signal output terminal of the analog-to-digital conversion unit, and includes a test signal filter and an impedance calculator connected to each other; An EEG signal processing sub-unit, which is electrically connected to the signal output terminal of the analog-to-digital conversion unit, and includes an EEG signal filter and an EEG signal processor connected to each other.

4. The electroencephalogram detection device according to claim 1, characterized in that, The analog processing unit includes a filter amplification circuit and a driving circuit. The signal input terminal of the filter amplification circuit is connected to the signal input terminal of the impedance network, the signal output terminal of the filter amplification circuit is connected to the signal input terminal of the analog-to-digital conversion unit, and the driving terminal of the driving circuit is connected to the driven terminal of the impedance network.

5. The electroencephalogram detection device according to claim 4, characterized in that, The impedance network includes at least two EEG signal test electrodes, an impedance test auxiliary electrode, and a driving auxiliary electrode. The EEG signal test electrodes are respectively connected to the signal input terminal of the filter amplification circuit, the impedance test auxiliary electrode is connected to the signal input terminal of the filter amplification circuit, and the driving auxiliary electrode is connected to the driving terminal of the driving circuit.

6. The EEG detection device according to claim 5, wherein The switch circuit unit includes at least two groups of signal test switches and a first switch. The signal test switches correspond one-to-one to the electroencephalogram (EEG) signal test electrodes. The signal test switches include a first signal test switch and a second signal test switch. One end of the first signal test switch is connected to the signal output end of the EEG signal test electrode, the signal input end of the filter amplification circuit, and the node of the second signal test switch. The other end of the first signal test switch is connected to the positive power supply. One end of the second signal test switch is connected to the signal output end of the EEG signal test electrode, the signal input end of the filter amplification circuit, and the node of the first signal test switch. The other end of the second signal test switch is connected to the node of the driving end of the driving circuit and the driven end of the impedance network. One end of the first switch is connected to the negative power supply, and the other end of the first switch is connected to the signal input end of the filter amplification circuit.

7. An impedance detection method for the electroencephalogram detection device according to any one of claims 1 to 6, characterized in that, The steps of the impedance detection method of the EEG detection device include: Obtain a control instruction and select the working mode of the EEG detection device according to the control instruction; If the EEG acquisition mode is selected, acquire EEG signals and generate an EEG signal processing result according to the EEG signals; If the impedance detection mode is selected, obtain a power supply test signal, generate an impedance detection signal according to the power supply test signal, and obtain a theoretical contact impedance based on the impedance detection signal.

8. The impedance detection method of the electroencephalogram detection device according to claim 7, characterized in that, The step of obtaining the theoretical contact impedance based on the impedance detection signal includes: Obtain the current amplitude of the current source and the circuit amplification gain; Calculate the theoretical contact impedance according to the current amplitude, the circuit amplification gain, and the impedance detection signal.

9. A storage medium, characterized in that, An impedance detection program of an EEG detection device is stored on the storage medium. When the impedance detection program of the EEG detection device is executed by a processor, the steps of the EEG detection device described in any one of claims 7 to 8 are implemented.

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