Electroencephalogram acquisition circuit and electroencephalogram acquisition equipment

Abstract

The embodiment of the invention relates to the technical field of electroencephalogram collection, and provides an electroencephalogram collection circuit and electroencephalogram collection equipment. The electroencephalogram collection circuit comprises a collection unit, a transmission unit and a processor unit; the acquisition unit comprises a first electrode, a second electrode, a third electrode and a fourth electrode; the transmission unit comprises a first transmission circuit, a second transmission circuit and a third transmission circuit; the electroencephalogram acquisition circuit can form three transmission channels through three transmission circuits, and the three transmission channels multiplex electrodes corresponding to four acquisition points to obtain electroencephalogram signals in various modes so as to meet various scene requirements.

Description

Technical Field

[0001] The present application relates to the technical field of electroencephalogram (EEG) signal acquisition, and more specifically, to an EEG acquisition circuit and an EEG acquisition device. Background Art

[0002] The working principle of the brainwave collector is to collect the EEG signals of the target user's cerebral cortex, transmit them to the signal processing unit for preprocessing, amplification and digitization, and perform real-time monitoring and data analysis on the target user based on the processed data.

[0003] However, due to factors such as human activities and external interference, the accuracy and stability of the EEG signals collected by the EEG collector are poor. Summary of the invention

[0004] The embodiments of the present application provide an EEG acquisition circuit and an EEG acquisition device to improve the continuity, accuracy and stability of EEG signals.

[0005] In a first aspect, an embodiment of the present application provides an EEG acquisition circuit, the EEG acquisition circuit comprising an acquisition unit, a transmission unit and a processor unit; the acquisition unit comprises a first electrode, a second electrode, a third electrode and a fourth electrode, wherein the first electrode is used to acquire a first EEG signal of an acquisition point FP1, the third electrode is used to acquire a second EEG signal of an acquisition point FP2, the second electrode is used to acquire a third EEG signal of an acquisition point VREF2, and the fourth electrode is used to acquire a fourth EEG signal of an acquisition point VREF1; the transmission unit comprises a first transmission circuit, a second transmission circuit and a third transmission circuit; one end of the first transmission circuit is connected to the processor unit, the other end of the first transmission circuit is connected to the first electrode and the third electrode, the first transmission circuit is used to form a first potential difference between the first EEG signal and the second EEG signal, and transmit the first potential difference to the processor unit;

[0006] One end of the second transmission circuit is connected to the processor unit, and the other end of the second transmission circuit is connected to the first electrode and the second electrode, and the second transmission circuit is used to form a second potential difference between the first EEG signal and the third EEG signal, and transmit the second potential difference to the processor unit;

[0007] One end of the third transmission circuit is connected to the processor unit, and the other end of the third transmission circuit is connected to the third electrode and the fourth electrode. The first transmission circuit is used to form a third potential difference between the fourth EEG signal and the second EEG signal, and transmit the third potential difference to the processor unit.

[0008] Optionally, the first transmission circuit includes a first analog front end, a first tunable filter, a first capacitor and a second capacitor, one end of the first analog front end is connected to the processor unit, the other end of the first analog front end is connected to one end of the first tunable filter, the other end of the first tunable filter is respectively connected to one end of the first capacitor and one end of the second capacitor, the other end of the first capacitor is connected to the first electrode, and the other end of the second capacitor is connected to the third electrode;

[0009] The second transmission circuit comprises a second analog front end, a second tuned filter, a third capacitor and a fourth capacitor, one end of the second analog front end is connected to the processor unit, the other end of the second analog front end is connected to one end of the second tuned filter, the other end of the second tuned filter is respectively connected to one end of the third capacitor and one end of the fourth capacitor, the other end of the third capacitor is connected to the first electrode, and the other end of the fourth capacitor is connected to the second electrode;

[0010] The third transmission circuit includes a third analog front end, a third tuned filter, a fifth capacitor and a sixth capacitor. One end of the third analog front end is connected to the processor unit, the other end of the third analog front end is connected to one end of the third tuned filter, the other end of the third tuned filter is respectively connected to one end of the fifth capacitor and one end of the sixth capacitor, the other end of the fifth capacitor is connected to the third electrode, and the other end of the sixth capacitor is connected to the fourth electrode.

[0011] Optionally, the first transmission circuit further includes a first switch and a second switch, the first switch includes a first output terminal, a first input terminal, and a second input terminal, and the second switch includes a second output terminal, a third input terminal, and a fourth input terminal;

[0012] The first output terminal is connected to the other end of the first capacitor, the first input terminal is connected to the first electrode, and the second input terminal is connected to the second electrode;

[0013] The second output terminal is connected to the other end of the second capacitor, the third input terminal is connected to the third electrode, and the fourth input terminal is connected to the fourth electrode.

[0014] Optionally, the processor unit is used to receive the first potential difference, the second potential difference and the third potential difference, and determine the detection result of the acquisition unit based on the first potential difference, the second potential difference and the third potential difference, and the detection result includes the connection status of the first electrode, the second electrode, the third electrode and the fourth electrode, and the connection status includes normal connection, detachment and poor contact.

[0015] Optionally, the processor unit is further configured to control a first connection state of the first switch and / or control a second connection state of the second switch according to a detection result.

[0016] Optionally, the processor unit is also used to obtain monitoring scene information, and determine the required type of EEG signal based on the monitoring scene information, and control the first connectivity state of the first switch and / or control the second connectivity state of the second switch according to the required type of EEG signal.

[0017] In a second aspect, an EEG acquisition device is provided, including an EEG acquisition circuit, wherein the EEG acquisition circuit includes an acquisition unit, a transmission unit and a processor unit; the acquisition unit includes a first electrode, a second electrode, a third electrode and a fourth electrode, wherein the first electrode is used to acquire a first EEG signal of an acquisition point FP1, the third electrode is used to acquire a second EEG signal of an acquisition point FP2, the second electrode is used to acquire a third EEG signal of an acquisition point VREF2, and the fourth electrode is used to acquire a fourth EEG signal of an acquisition point VREF1; the transmission unit includes a first transmission circuit, a second transmission circuit and a third transmission circuit;

[0018] One end of the first transmission circuit is connected to the processor unit, and the other end of the first transmission circuit is connected to the first electrode and the third electrode, and the first transmission circuit is used to form a first potential difference between the first EEG signal and the second EEG signal, and transmit the first potential difference to the processor unit; one end of the second transmission circuit is connected to the processor unit, and the other end of the second transmission circuit is connected to the first electrode and the second electrode, and the second transmission circuit is used to form a second potential difference between the first EEG signal and the third EEG signal, and transmit the second potential difference to the processor unit;

[0019] One end of the third transmission circuit is connected to the processor unit, and the other end of the third transmission circuit is connected to the third electrode and the fourth electrode. The first transmission circuit is used to form a third potential difference between the fourth EEG signal and the second EEG signal, and transmit the third potential difference to the processor unit.

[0020] Optionally, the first transmission circuit further includes a first switch and a second switch, the first switch includes a first output terminal, a first input terminal, and a second input terminal, and the second switch includes a second output terminal, a third input terminal, and a fourth input terminal;

[0021] The first output terminal is connected to the other end of the first capacitor, the first input terminal is connected to the first electrode, and the second input terminal is connected to the second electrode;

[0022] The second output terminal is connected to the other end of the second capacitor, the third input terminal is connected to the third electrode, and the fourth input terminal is connected to the fourth electrode.

[0023] Optionally, the processor unit is used to receive the first potential difference, the second potential difference and the third potential difference, and determine the detection result of the acquisition unit based on the first potential difference, the second potential difference and the third potential difference, and the detection result includes the connection status of the first electrode, the second electrode, the third electrode and the fourth electrode, and the connection status includes normal connection, detachment and poor contact.

[0024] Optionally, the processor unit is further configured to control a first connection state of the first switch and / or control a second connection state of the second switch according to a detection result.

[0025] The EEG acquisition circuit can obtain EEG signals of various modes through three transmission circuits to meet the needs of various scenarios. For example, the first transmission circuit is used to form a first potential difference between the EEG signal corresponding to the acquisition point FP1 and the EEG signal corresponding to the acquisition point FP2, and send the first potential difference to the processor unit; the second transmission circuit can form a second potential difference between the EEG signal corresponding to the acquisition point FP1 and the EEG signal corresponding to the acquisition point VREF2, and send the second potential difference to the processor unit. The third transmission circuit can form a third potential difference between the EEG signal corresponding to the acquisition point FP2 and the EEG signal corresponding to the acquisition point VREF1, and send the third potential difference to the processor unit. The three transmission channels formed by the three transmission circuits transmit three modes of EEG signals, so that the EEG acquisition circuit can be applied to a variety of scenarios. For example, the EEG signal transmitted by the first transmission circuit can be used in the sleep monitoring scenario, and the EEG signal transmitted by the second transmission circuit can be used in the sleep monitoring, left and right brain signal delay analysis and other scenarios. Two or three signals can realize sleep monitoring, depression analysis, fatigue analysis and other scenarios, and improve the adaptability of the EEG acquisition circuit. Three transmission channels multiplex four collection points. Multiple scenario requirements can be met by multiplexing four collection points. Three modes of EEG signals are transmitted through three transmission channels to improve the accuracy and stability of EEG signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of an EEG acquisition circuit provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the structure of an analog front end provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of the structure of another EEG acquisition circuit provided in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of the structure of another EEG acquisition circuit provided in an embodiment of the present application;

[0030] Figure 5 A schematic diagram of the structure of another EEG acquisition circuit provided in an embodiment of the present application;

[0031] Figure 6 A schematic diagram of the structure of another EEG acquisition circuit provided in an embodiment of the present application;

[0032] Figure 7 A schematic diagram of the structure of an electroencephalogram (EEG) acquisition device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] See also Figure 1 , Figure 1 A schematic diagram of the structure of an EEG acquisition circuit provided in an embodiment of the present application. Figure 1 The EEG acquisition circuit includes an acquisition unit, a transmission unit and a processor unit, wherein the acquisition unit is connected to the transmission unit, and the transmission unit is connected to the processor unit.

[0037] The acquisition unit is used to collect the EEG signals of the target user, the transmission unit is used to preprocess the EEG signals and send the preprocessed EEG signals (such as the first potential difference, the second potential difference or the third potential difference described below) to the processor unit; the processor unit is used to process and analyze the EEG signals.

[0038] Optionally, the processor unit may be a module having a data processing function such as a central processing unit (CPU) or a microcontroller unit (MCU).

[0039] Optionally, after the processor unit obtains the preprocessed EEG signal, it can also send the preprocessed EEG signal to an electronic device, which processes and analyzes the preprocessed EEG signal. For example, the processor unit sends the preprocessed EEG signal to the electronic device via Bluetooth, card storage, etc.

[0040] Optionally, Figure 1 In the embodiment, the acquisition unit includes a first electrode, a second electrode, a third electrode and a fourth electrode. The first electrode is used to acquire a first EEG signal of an acquisition point FP1, the third electrode is used to acquire a second EEG signal of an acquisition point FP2, the second electrode is used to acquire a third EEG signal of an acquisition point VREF2, and the fourth electrode is used to acquire a fourth EEG signal of an acquisition point VREF1.

[0041] Among them, the EEG signals corresponding to the acquisition points VREF2 and VREF1 are reference signals, and the second electrode and the fourth electrode are reference electrodes, which provide potential reference and offset electrical noise during the acquisition process. The reference electrode is a point used to provide a potential reference, and its potential is regarded as zero potential during the acquisition process.

[0042] Optionally, Figure 1 The collection points corresponding to the first electrode, the second electrode, the third electrode and the fourth electrode are determined based on the international standard 10-20 system or an extension thereof, such as the collection points of the target user.

[0043] Optionally, the acquisition point FP1 is located at the left frontal pole, 10% to the left of FPz (frontal pole midline, 10% posterior from the nasion). The acquisition point FP2 is located at the right frontal pole, corresponding to FP1, and located on the right side.

[0044] Optionally, Figure 1 In the embodiment, the transmission unit includes a first transmission circuit, a second transmission circuit and a third transmission circuit.

[0045] One end of the first transmission circuit is connected to the processor unit, and the other end of the first transmission circuit is connected to the first electrode and the third electrode. The first transmission circuit is used to form a first potential difference between the first EEG signal and the second EEG signal, and transmit the first potential difference to the processor unit;

[0046] One end of the second transmission circuit is connected to the processor unit, and the other end of the second transmission circuit is connected to the first electrode and the second electrode. The second transmission circuit is used to form a second potential difference between the first EEG signal and the third EEG signal, and transmit the second potential difference to the processor unit;

[0047] One end of the third transmission circuit is connected to the processor unit, and the other end of the third transmission circuit is connected to the third electrode and the fourth electrode. The first transmission circuit is used to form a third potential difference between the second EEG signal and the fourth EEG signal, and transmit the third potential difference to the processor unit. Figure 1 The EEG acquisition circuit can obtain EEG signals of various modes through three transmission circuits to meet the needs of various scenarios. For example, the first transmission circuit is used to form a first potential difference between the EEG signal corresponding to the acquisition point FP1 and the EEG signal corresponding to the acquisition point FP2, and send the first potential difference to the processor unit; the second transmission circuit can form a second potential difference between the EEG signal corresponding to the acquisition point FP1 and the EEG signal corresponding to the acquisition point VREF2, and send the second potential difference to the processor unit. The third transmission circuit can form a third potential difference between the EEG signal corresponding to the acquisition point FP2 and the EEG signal corresponding to the acquisition point VREF1, and send the third potential difference to the processor unit. The three transmission channels formed by the three transmission circuits transmit three modes of EEG signals, so that the EEG acquisition circuit can be applied to a variety of scenarios. For example, the EEG signal transmitted by the first transmission circuit can be used in the sleep monitoring scenario, and the EEG signal transmitted by the second transmission circuit can be used in the sleep monitoring, left and right brain signal delay analysis and other scenarios. Two or three signals can realize sleep monitoring, depression analysis, fatigue analysis and other scenarios, and improve the adaptability of the EEG acquisition circuit. The three transmission channels reuse four acquisition points, and the needs of various scenarios can be met by multiplexing four acquisition points through three transmission channels. Three modes of EEG signals are transmitted through three transmission channels to improve the accuracy and stability of EEG signals.

[0048] Optionally, the first transmission circuit, the second transmission circuit and the third transmission circuit have the same structure, that is, the three transmission circuits use the same circuit structure to transmit the preprocessed EEG signal (such as the first potential difference, the second potential difference or the third potential difference) to the processor unit.

[0049] Optionally, the first electrode and the third electrode are respectively connected to the positive and negative input terminals of the first transmission circuit, and the first transmission circuit forms a first potential difference based on the EEG signals at the positive and negative input terminals; the first electrode and the second electrode are respectively connected to the positive and negative input terminals of the second transmission circuit, and the second transmission circuit forms a second potential difference based on the EEG signals at the positive and negative input terminals; the third electrode and the fourth electrode are respectively connected to the positive and negative input terminals of the third transmission circuit, and the third transmission circuit forms a third potential difference based on the EEG signals at the positive and negative input terminals.

[0050] Optionally, the first transmission circuit includes a first analog front end, a first tuned filter, a first capacitor and a second capacitor, one end of the first analog front end is connected to the processor unit, the other end of the first analog front end is connected to one end of the first tuned filter, the other end of the first tuned filter is respectively connected to one end of the first capacitor and one end of the second capacitor, the other end of the first capacitor is connected to the first electrode, and the other end of the second capacitor is connected to the third electrode;

[0051] The second transmission circuit includes a second analog front end, a second tuned filter, a third capacitor and a fourth capacitor, one end of the second analog front end is connected to the processor unit, the other end of the second analog front end is connected to one end of the second tuned filter, the other end of the second tuned filter is respectively connected to one end of the third capacitor and one end of the fourth capacitor, the other end of the third capacitor is connected to the first electrode, and the other end of the fourth capacitor is connected to the second electrode;

[0052] The third transmission circuit includes a third analog front end, a third tuned filter, a fifth capacitor and a sixth capacitor. One end of the third analog front end is connected to the processor unit, the other end of the third analog front end is connected to one end of the third tuned filter, the other end of the third tuned filter is respectively connected to one end of the fifth capacitor and one end of the sixth capacitor, the other end of the fifth capacitor is connected to the third electrode, and the other end of the sixth capacitor is connected to the fourth electrode.

[0053] Among them, the capacitors between the electrodes and the tuned filters in the three transmission circuits perform preliminary processing and filtering on the EEG signals collected by the electrodes to remove high-frequency noise to improve the stability of the EEG signals.

[0054] Optionally, if the frequency of the EEG signal required by the processor unit is 1 Hz to 30 Hz, high-frequency noise with a frequency greater than 30 Hz in the EEG signal collected by the four electrodes may be filtered out by capacitors.

[0055] The tuning filters and capacitors in the three transmission circuits cooperate to selectively filter out an EEG signal of a specific frequency, so that the filtered EEG signal can be transmitted to the corresponding analog front end with complete characteristics.

[0056] The corresponding analog front end in the three transmission circuits can collect external physical quantities or electrical signals through sensors and other components, amplify, filter, convert and process the filtered EEG signals, and transmit the processed signals (such as potential difference) to the processor unit.

[0057] See also Figure 2 , Figure 2 A schematic diagram of the structure of an analog front end provided in an embodiment of the present application is shown in FIG. Figure 2 The analog front end in this can be applied to Figure 1 The first analog front end, the second analog front end and the third analog front end.

[0058] Figure 2 The analog front end includes analog signal acquisition, analog signal amplification, analog signal processing, analog-to-digital conversion and digital signal processing, wherein the analog signal acquisition is connected to the corresponding tuned filter to obtain the EEG signal filtered by the tuned filter; one end of the analog signal amplifier is connected to the analog signal collector, and the other end of the analog signal amplifier is connected to the analog signal processor, and the analog signal amplifier is used to amplify the filtered EEG signal; one end of the analog signal processing is connected to the analog signal amplifier, and the other end of the analog signal processing is connected to the analog-to-digital converter, and the analog signal processing is used to process the amplified EEG signal, such as filtering, isolating, linearizing and other operations on the amplified EEG signal; one end of the analog-to-digital converter is connected to the analog signal processing, and the other end of the analog-to-digital converter is connected to the digital signal processing, and the analog-to-digital converter is used to convert the analog signal into a digital signal (such as a potential difference), and the digital signal processing is used to filter, transform, detect, spectrally analyze, estimate, compress, identify and other processes on the EEG signal.

[0059] See also Figure 3 , Figure 3 A schematic diagram of another EEG acquisition circuit provided in an embodiment of the present application. Figure 3 and Figure 1 The EEG acquisition circuit is similar to that in the embodiment of the present invention, and the EEG acquisition circuit includes an acquisition unit, a transmission unit and a processor unit. The acquisition unit includes a first electrode, a second electrode, a third electrode and a fourth electrode, and the transmission unit includes a first transmission circuit, a second transmission circuit and a third transmission circuit. One end of the three transmission circuits is connected to the acquisition unit, and the other end of the three transmission circuits is connected to the processor unit. The three transmission circuits are used to pre-process the EEG signals collected by the acquisition unit and send the pre-processed EEG signals (i.e., the first potential difference, the second potential difference and the third potential difference) to the processor unit. The first transmission circuit includes a first analog front end, a first tuned filter, a first capacitor and a second capacitor, the second transmission circuit includes a second analog front end, a second tuned filter, a third capacitor and a fourth capacitor; the third transmission circuit includes a third analog front end, a third tuned filter, a fifth capacitor and a sixth capacitor; the difference is that:

[0060] The first transmission circuit further includes a first switch and a second switch, the first switch includes a first output terminal, a first input terminal and a second input terminal, and the second switch includes a second output terminal, a third input terminal and a fourth input terminal;

[0061] The first output terminal is connected to the other end of the first capacitor, the first input terminal is connected to the first electrode, and the second input terminal is connected to the second electrode;

[0062] The second output terminal is connected to the other end of the second capacitor, the third input terminal is connected to the third electrode, and the fourth input terminal is connected to the fourth electrode.

[0063] Optionally, the first switch and the second switch may be single-pole double-throw switches or other types of switches.

[0064] Optionally, the first switch and the second switch are controllable switches, and a first connectivity state of the first switch can be controlled by a processor unit, the first connectivity state comprising the first output terminal and the first input terminal being connected, the first output terminal and the second input terminal being disconnected, or the first output terminal and the first input terminal being disconnected, and the first output terminal and the second input terminal being connected; a second connectivity state of the second switch can also be controlled by a processor unit, the second connectivity state comprising the second output terminal and the third input terminal being connected, the second output terminal and the fourth input terminal being disconnected, or the second output terminal and the third input terminal being disconnected, and the second output terminal and the fourth input terminal being connected.

[0065] Among them, the first switch and the second switch are both controllable switches, and the processor unit can control the connectivity state of the first switch and the second switch through control instructions, so that the three transmission circuits can form EEG signals of different modes to adapt to different test scenarios.

[0066] Optionally, the first connected state further includes the first output terminal and the first input terminal being disconnected and the first output terminal and the second input terminal being disconnected, and the second connected state includes the second output terminal and the third input terminal being disconnected and the second output terminal and the fourth input terminal being disconnected.

[0067] Optionally, the second transmission circuit further includes a third switch and a fourth switch, the third switch includes a third output terminal, a fifth input terminal and a sixth input terminal, and the fourth switch includes a fourth output terminal, a seventh input terminal and an eighth input terminal;

[0068] The third output terminal is connected to the other end of the third capacitor, the fifth input terminal is connected to the first electrode, and the sixth input terminal is connected to the second electrode;

[0069] The fourth output terminal is connected to the other end of the fourth capacitor, the seventh input terminal is connected to the third electrode, and the eighth input terminal is connected to the fourth electrode.

[0070] Among them, the third switch and the fourth switch are both controllable switches, and the processor unit can control the connectivity state of the third switch and the fourth switch through control instructions to adapt to different test scenarios.

[0071] During EEG acquisition, electrodes may fall off due to human movement, external interference and other factors. Electrode detachment refers to the phenomenon that the electrode is unintentionally detached from the scalp during EEG monitoring. This situation may affect the accuracy and continuity of EEG monitoring, thereby affecting the evaluation and diagnosis of the patient's EEG activity. In EEG monitoring, electrode detachment can lead to signal loss or inaccurate data, which may affect the doctor's interpretation of the patient's EEG activity. For example, in epilepsy monitoring, electrode detachment may result in missing the EEG features of epileptic seizures, thus affecting diagnosis and treatment decisions.

[0072] Optionally, three types of EEG signals are transmitted through three transmission units, and the processor unit can determine whether the four electrodes of the acquisition unit are detached, and which electrodes have detached, based on the received EEG signals (such as the first potential difference, the second potential difference, and the third potential difference), so as to notify the user in time to repair them and avoid signal loss or inaccurate data.

[0073] The connection status of the electrode includes normal connection, detachment and poor contact. If the electrode detaches, the electrode cannot collect the EEG signal of the target user. If the electrode is normally connected, the electrode can collect the EEG signal of the collection point normally. If the electrode has poor contact, the electrode can collect the EEG signal of the collection point, but the EEG signal has problems with integrity and accuracy.

[0074] Since each electrode has a different connection status, when the connection status of the electrode changes, the EEG signal received by the processor (such as the first potential difference, the second potential difference, and the third potential difference) will also change. The processor unit can analyze the received EEG signal to determine the connection status of the four electrodes.

[0075] For example, Figure 1 As shown, if none of the four electrodes fall off, the signals received by the processor unit are the first potential difference, the second potential difference, and the third potential difference.

[0076] If the first electrode falls off, the first electrode cannot collect the EEG signal of the target user, the first transmission circuit is used to transmit the EEG signal collected by the third electrode (i.e., the EEG signal corresponding to the collection point FP2), the second transmission circuit is used to transmit the signal of the collection point corresponding to the reference electrode (i.e., the EEG signal corresponding to the collection point VREF2), the third transmission circuit is used to transmit the third potential difference between the EEG signal corresponding to the collection point FP2 and the EEG signal corresponding to the collection point VREF1, and the signals received by the processor unit are: the EEG signal corresponding to the collection point FP2, the EEG signal corresponding to the collection point VREF2 and the third potential difference;

[0077] If the second electrode falls off, the second electrode cannot collect the EEG signal of the target user. The first transmission circuit is used to transmit the potential difference between the EEG signal corresponding to the collection point FP1 and the EEG signal corresponding to the collection point FP2 (i.e., the first potential difference), the second transmission circuit is used to transmit the EEG signal corresponding to the collection point FP1, and the third transmission circuit is used to transmit the potential difference between the EEG signal corresponding to the collection point FP2 and the EEG signal corresponding to the collection point VREF1 (i.e., the third potential difference); the signals received by the processor unit are: the first potential difference, the EEG signal corresponding to the collection point FP1, and the third potential difference.

[0078] If the third electrode falls off, the third electrode cannot collect the EEG signal of the target user. The first transmission circuit is used to transmit the EEG signal corresponding to the collection point FP1, the second transmission circuit is used to transmit the potential difference (i.e., the second potential difference) between the EEG signal corresponding to the collection point FP1 and the EEG signal corresponding to the collection point VREF1, and the third transmission circuit is used to transmit the EEG signal corresponding to the collection point VREF1; the signals received by the processor unit are: the EEG signal corresponding to the collection point FP1, the EEG signal corresponding to the collection point FP1, and the EEG signal corresponding to the collection point VREF1.

[0079] If the first electrode and the second electrode fall off, the first electrode and the second electrode cannot collect the EEG signal of the target user, and the first transmission circuit transmits the EEG signal corresponding to the collection point FP2; the second transmission circuit has no EEG signal to transmit, and the third transmission circuit transmits the potential difference between the EEG signal corresponding to the collection point FP2 and the EEG signal corresponding to the collection point VREF1. The signals received by the processor unit are: the EEG signal corresponding to the collection point FP2, no signal, and the third potential difference.

[0080] From the above, it can be seen that among the four electrodes of the collection unit, the four electrodes have different connection states, and the signals received by the processor unit are also different. The processor unit can determine the detection result of the collection unit based on the received signal and analyze the signal. The detection result includes the connection state of the first electrode, the second electrode, the third electrode, and the fourth electrode. The connection state includes normal connection, detachment, and poor contact.

[0081] Optionally, a correspondence between the different connection states of the four electrodes of the acquisition unit and the categories of the EEG signals received by the processor unit can be established, so that after the processor unit receives the EEG signals transmitted by the three transmission circuits, it analyzes the EEG signals to determine the types of the EEG signals, and determines the detection results according to the categories and the correspondence. In this way, the detachment of the four electrodes can be accurately determined.

[0082] Optionally, the processor unit can construct a data set based on the EEG signals collected under different electrode connection states, and train the electrode detachment detection model based on the data set. In this way, after the processor unit receives the EEG signals transmitted by the three transmission units, the received EEG signals can be input into the electrode detachment detection model to obtain a detection result.

[0083] Optionally, the processor unit may analyze the received EEG signal through a noise analysis algorithm to determine whether there is electrode detachment. If there is electrode detachment, the detection result also includes the location where the electrode detachment occurs. For example, the EEG signal received by the processor unit is analyzed through a noise analysis algorithm, and the detection result is determined based on the analysis result. The corresponding relationship between the analysis result and the detection result may be pre-stored, so that the processor unit can determine the detection result based on the analysis result and the corresponding relationship.

[0084] Optionally, the processor unit can detect the received EEG signal through an active dropout detection algorithm to determine the detection result. For example, the processor unit preprocesses the collected EEG signal, such as filtering, denoising, etc., and then extracts characteristic information that can reflect the electrode dropout from the processed data, such as the characteristics of the EEG signals transmitted by the three transmission units. Based on the extracted characteristic information, the state of the object or device is judged using a preset algorithm or model to determine the detection result.

[0085] Optionally, after the processor unit detects that the electrode has fallen off, it is further used to generate an alarm message, and to indicate to the user through the alarm message that the electrode of the acquisition unit has fallen off and the electrode that has fallen off.

[0086] Optionally, the processor unit can present alarm information through a visual device, for example, by presenting four indicator lights through a visual device, and the four indicator lights are used to indicate the connection status of the four electrodes of the collection unit. If the indicator light corresponding to the electrode is red, it means that the electrode has fallen off; if the indicator light corresponding to the electrode is green, it means that the electrode is in good contact; if the indicator light corresponding to the electrode is yellow, it means that the electrode is in poor contact with the collection point of the target user, and the EEG signal of the collection point can be collected, but the EEG signal has problems with accuracy and completeness.

[0087] After detecting that at least one of the four electrodes of the acquisition unit has fallen off, the EEG acquisition function of the EEG acquisition circuit can be reorganized. EEG acquisition function reorganization refers to a series of technologies and methods adopted during the EEG monitoring process to solve problems such as electrode detachment or incomplete signal acquisition to restore or optimize the EEG acquisition function, so as to achieve continuity, accuracy and reliability of EEG signal acquisition, thereby providing high-quality EEG data for clinical diagnosis and scientific research.

[0088] Optionally, the processor unit is also used to control the first connectivity state of the first switch and / or control the second connectivity state of the second switch according to the detection result, so as to realize the reorganization of the brain wave acquisition function of the brain wave acquisition circuit. If the electrode falls off, and the brain wave signal collected by the electrode that has not fallen off meets the needs of the monitoring scene, there is no need to change the connectivity state of the first switch or the second switch. If the electrode falls off, and the brain wave signal collected by the electrode that has not fallen off does not meet the needs of the monitoring scene, the processor unit can control to change the connectivity state of the first switch or the second switch to realize the reorganization of the brain wave acquisition function of the brain wave acquisition circuit, so that the brain wave signal collected by the reorganized brain wave acquisition circuit can meet the needs of the monitoring scene.

[0089] See also Figure 4 , Figure 4 A schematic diagram of the structure of an EEG acquisition circuit provided in an embodiment of the present application.

[0090] Figure 4 The EEG acquisition circuit includes a processor unit, a transmission circuit, an electrode 1 and an electrode 3. One end of the transmission circuit is connected to the processor unit, and the other end of the transmission circuit is connected to the electrode 1 and the electrode 3. The electrode 1 is used to acquire a first EEG signal at the acquisition point FP1, and the electrode 3 is used to acquire a second EEG signal at the acquisition point FP2. The transmission circuit is used to form a first potential difference between the first EEG signal and the second EEG signal, and send the first potential difference to the processor unit.

[0091] Optionally, the transmission circuit can be connected with Figure 2 The structure of the analog front end is the same as that of the analog front end, and other structures can also be used.

[0092] See also Figure 5 , Figure 5 A schematic diagram of the structure of an EEG acquisition circuit provided in an embodiment of the present application.

[0093] Figure 5 The EEG acquisition circuit includes a processor unit, a transmission circuit 1, a transmission circuit 2, an electrode 1, an electrode 2, an electrode 3, and an electrode 4. One end of the transmission circuit 1 is connected to the processor unit, and the other end of the transmission circuit 1 is connected to the electrode 1 and the electrode 2; one end of the transmission circuit 2 is connected to the processor unit, and the other end of the transmission circuit 2 is connected to the electrode 3 and the electrode 4. The electrode 1 is used to collect the first EEG signal of the acquisition point FP1, the electrode 3 is used to collect the second EEG signal of the acquisition point FP2, the electrode 2 is used to collect the third EEG signal of the acquisition point VREF2, and the electrode 4 is used to collect the fourth EEG signal of the acquisition point VREF1.

[0094] Transmission circuit 1 is used to form a second potential difference between the first EEG signal and the third EEG signal, and send the second potential difference to the processor unit. Transmission circuit 2 is used to form a third potential difference between the second EEG signal and the fourth EEG signal, and send the third potential difference to the processor unit.

[0095] See also Figure 6 , Figure 6 A schematic diagram of the structure of an EEG acquisition circuit provided in an embodiment of the present application.

[0096] Figure 6 The EEG acquisition circuit includes a processor unit, an analog front end, a tuned filter, capacitor 1, capacitor 2, electrode 1 and electrode 3. One end of the analog front end is connected to the processor unit, the other end of the analog front end is connected to one end of the tuned filter, the other end of the tuned filter is connected to one end of capacitor 1 and one end of capacitor 2, the other end of capacitor 1 is connected to electrode 1, and the other end of capacitor 2 is connected to electrode 3. Electrode 1 is used to collect a first EEG signal at a collection point FP1, and electrode 3 is used to collect a second EEG signal at a collection point FP2. The analog front end, the tuned filter, capacitor 1 and capacitor 2 cooperate to form a first potential difference between the first EEG signal and the second EEG signal, and send the first potential difference to the processor unit.

[0097] in, Figure 1 or Figure 3 The EEG acquisition circuit in the system can transmit three potential differences through three transmission circuits. Figure 4 The EEG acquisition circuit in the system can transmit a potential difference through a transmission circuit. Figure 5 The brain electrical acquisition circuit can transmit two potential differences through two transmission circuits. Figure 6 The brain electrical acquisition circuit can transmit a potential difference through a transmission circuit.

[0098] Optionally, in order to perform EEG monitoring on the target user, the types of EEG signals that can be obtained include: a first potential difference, a second potential difference, a third potential difference, a first EEG signal corresponding to the acquisition point FP1, and a second EEG signal corresponding to the acquisition point FP2. The required type of EEG signal can be determined according to the monitoring scene information, and the first connection state of the first switch and / or the connection state of the second switch can be controlled according to the EEG signal, so that the corresponding EEG signal can be obtained. The monitoring scene information is used to indicate the type of EEG signal required for the monitoring. Exemplarily, if the EEG signal required for monitoring scene 1 is the first potential difference, the second potential difference, and the third potential difference, and the EEG acquisition circuit can obtain the first potential difference, the second potential difference, and the third potential difference under the current first connection state of the first switch and the connection state of the second switch, then there is no need to change the connection state of the first switch or the second switch. If the third electrode falls off, the EEG signal required for monitoring scene 2 is the first EEG signal and the second potential difference corresponding to the acquisition point FP1, and the processor unit can control the first connection state of the first switch and the connection state of the second switch to obtain the first EEG signal and the second potential difference corresponding to the acquisition point FP1.

[0099] Optionally, after obtaining the detection results, the processor unit may obtain monitoring scene information, and determine the required type of EEG signal based on the monitoring scene information, and control the first connectivity state of the first switch and / or control the second connectivity state of the second switch according to the required type of EEG signal and the detection results, so as to obtain the required EEG signal.

[0100] Optionally, the processor unit may control the connection status of a plurality of switches, where the plurality of switches include one or more of a first switch, a second switch, a third switch and a fourth switch.

[0101] See also Figure 7 , Figure 7 A schematic diagram of the structure of an EEG acquisition device provided in an embodiment of the present application, the EEG acquisition device includes an EEG acquisition circuit, and the EEG acquisition circuit can be the structure of any EEG acquisition circuit implemented above, and can realize the functions of the EEG acquisition circuit in any of the above embodiments.

[0102] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the above-mentioned embodiments, a person skilled in the art should understand that the technical solutions described in the above-mentioned embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. An electroencephalogram acquisition circuit, characterized in that: The EEG acquisition circuit includes an acquisition unit, a transmission unit and a processor unit; The acquisition unit includes a first electrode, a second electrode, a third electrode and a fourth electrode, wherein the first electrode is used to acquire a first EEG signal of an acquisition point FP1, the third electrode is used to acquire a second EEG signal of an acquisition point FP2, the second electrode is used to acquire a third EEG signal of an acquisition point VREF2, and the fourth electrode is used to acquire a fourth EEG signal of an acquisition point VREF1; The transmission unit includes a first transmission circuit, a second transmission circuit and a third transmission circuit; One end of the first transmission circuit is connected to the processor unit, and the other end of the first transmission circuit is connected to the first electrode and the third electrode, and the first transmission circuit is used to form a first potential difference between the first EEG signal and the second EEG signal, and transmit the first potential difference to the processor unit; One end of the second transmission circuit is connected to the processor unit, and the other end of the second transmission circuit is connected to the first electrode and the second electrode, and the second transmission circuit is used to form a second potential difference between the first EEG signal and the third EEG signal, and transmit the second potential difference to the processor unit; One end of the third transmission circuit is connected to the processor unit, and the other end of the third transmission circuit is connected to the third electrode and the fourth electrode. The first transmission circuit is used to form a third potential difference between the fourth EEG signal and the second EEG signal, and transmit the third potential difference to the processor unit.

2. The EEG acquisition circuit according to claim 1, characterized in that: The first transmission circuit includes a first analog front end, a first tunable filter, a first capacitor and a second capacitor, one end of the first analog front end is connected to the processor unit, the other end of the first analog front end is connected to one end of the first tunable filter, the other end of the first tunable filter is respectively connected to one end of the first capacitor and one end of the second capacitor, the other end of the first capacitor is connected to the first electrode, and the other end of the second capacitor is connected to the third electrode; The second transmission circuit comprises a second analog front end, a second tuned filter, a third capacitor and a fourth capacitor, one end of the second analog front end is connected to the processor unit, the other end of the second analog front end is connected to one end of the second tuned filter, the other end of the second tuned filter is respectively connected to one end of the third capacitor and one end of the fourth capacitor, the other end of the third capacitor is connected to the first electrode, and the other end of the fourth capacitor is connected to the second electrode; The third transmission circuit includes a third analog front end, a third tuned filter, a fifth capacitor and a sixth capacitor. One end of the third analog front end is connected to the processor unit, the other end of the third analog front end is connected to one end of the third tuned filter, the other end of the third tuned filter is respectively connected to one end of the fifth capacitor and one end of the sixth capacitor, the other end of the fifth capacitor is connected to the third electrode, and the other end of the sixth capacitor is connected to the fourth electrode.

3. The EEG acquisition circuit according to claim 2, characterized in that: The first transmission circuit further includes a first switch and a second switch, the first switch includes a first output terminal, a first input terminal and a second input terminal, and the second switch includes a second output terminal, a third input terminal and a fourth input terminal; The first output terminal is connected to the other end of the first capacitor, the first input terminal is connected to the first electrode, and the second input terminal is connected to the second electrode; The second output terminal is connected to the other end of the second capacitor, the third input terminal is connected to the third electrode, and the fourth input terminal is connected to the fourth electrode.

4. The EEG acquisition circuit according to any one of claims 1 to 3, characterized in that: The processor unit is used to receive the first potential difference, the second potential difference and the third potential difference, and determine the detection result of the acquisition unit according to the first potential difference, the second potential difference and the third potential difference, and the detection result includes the connection status of the first electrode, the second electrode, the third electrode and the fourth electrode, and the connection status includes normal connection, detachment and poor contact.

5. The EEG acquisition circuit according to claim 4, characterized in that: The processor unit is further configured to control a first connection state of the first switch and / or a second connection state of the second switch according to a detection result.

6. The EEG acquisition circuit according to any one of claims 3 to 5, characterized in that: The processor unit is also used to obtain monitoring scene information, and determine the required type of EEG signal based on the monitoring scene information, and control the first connectivity state of the first switch and / or control the second connectivity state of the second switch based on the required type of EEG signal.

7. An electroencephalogram acquisition device, characterized in that: It includes an EEG acquisition circuit, which includes an acquisition unit, a transmission unit and a processor unit; The acquisition unit includes a first electrode, a second electrode, a third electrode and a fourth electrode, wherein the first electrode is used to acquire a first EEG signal of an acquisition point FP1, the third electrode is used to acquire a second EEG signal of an acquisition point FP2, the second electrode is used to acquire a third EEG signal of an acquisition point VREF2, and the fourth electrode is used to acquire a fourth EEG signal of an acquisition point VREF1; The transmission unit includes a first transmission circuit, a second transmission circuit and a third transmission circuit; One end of the first transmission circuit is connected to the processor unit, and the other end of the first transmission circuit is connected to the first electrode and the third electrode, and the first transmission circuit is used to form a first potential difference between the first EEG signal and the second EEG signal, and transmit the first potential difference to the processor unit; One end of the second transmission circuit is connected to the processor unit, and the other end of the second transmission circuit is connected to the first electrode and the second electrode, and the second transmission circuit is used to form a second potential difference between the first EEG signal and the third EEG signal, and transmit the second potential difference to the processor unit; One end of the third transmission circuit is connected to the processor unit, and the other end of the third transmission circuit is connected to the third electrode and the fourth electrode. The first transmission circuit is used to form a third potential difference between the fourth EEG signal and the second EEG signal, and transmit the third potential difference to the processor unit.

8. The EEG acquisition device according to claim 7, characterized in that: The first transmission circuit further includes a first switch and a second switch, the first switch includes a first output terminal, a first input terminal and a second input terminal, and the second switch includes a second output terminal, a third input terminal and a fourth input terminal; The first output terminal is connected to the other end of the first capacitor, the first input terminal is connected to the first electrode, and the second input terminal is connected to the second electrode; The second output terminal is connected to the other end of the second capacitor, the third input terminal is connected to the third electrode, and the fourth input terminal is connected to the fourth electrode.

9. The EEG acquisition device as claimed in claim 7 or 8, characterized in that: The processor unit is used to receive the first potential difference, the second potential difference and the third potential difference, and determine the detection result of the acquisition unit according to the first potential difference, the second potential difference and the third potential difference, and the detection result includes the connection status of the first electrode, the second electrode, the third electrode and the fourth electrode, and the connection status includes normal connection, detachment and poor contact.

10. The EEG acquisition device according to claim 9, characterized in that: The processor unit is further configured to control a first connection state of the first switch and / or a second connection state of the second switch according to a detection result.

Images