Anti-interference electroencephalogram acquisition device

Abstract

The utility model provides an anti-interference electroencephalogram collecting device which comprises a collecting module and a signal processing module, the signal processing module is connected with the collecting module through a shielding transmission cable, and a shielding cover used for restraining radiation electromagnetic interference is arranged outside the signal processing module. And the shielding cover is connected with the shielding layer of the shielding transmission cable and the input end of the signal processing module in a single-point connection mode. When electroencephalogram signals are collected, the collecting module responds to control signals input externally, electroencephalogram signals of a patient begin to be collected, and the electroencephalogram signals are output after being subjected to signal processing such as filtering and amplifying through the signal processing module. According to the electroencephalogram signal acquisition device, multiple inhibition barriers of the shielding case and the shielding transmission cable are arranged, so that the interference of radiation electromagnetism on the acquired electroencephalogram signals is effectively inhibited, and the effectiveness and accuracy of electroencephalogram signal acquisition are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of electroencephalogram signal acquisition, and particularly relates to an electroencephalogram acquisition device with anti-interference function. Background Art

[0002] With the in-depth research on the human brain, electroencephalogram (EEG) signal acquisition devices are increasingly widely used. By identifying specific EEG signals, information interaction between the brain and external devices can be achieved. The acquired EEG signals serve as an important basis for judging brain activity information such as the conscious state of patients, and have important practical value in clinical medicine, ergonomics, rehabilitation medicine, sports science, etc. Therefore, higher requirements are placed on the stability and reliability of the stimulation, acquisition, and recognition analysis of EEG signals.

[0003] In the prior art, EEG signals are mainly obtained through acquisition electrodes attached to the scalp surface. After multiple acquisition electrodes acquire EEG analog signals, the signals need to be transmitted through relatively long cables. Since EEG analog signals are very weak and easily affected by external interference, the EEG analog signals obtained by multiple acquisition electrodes are prone to interference from the complex external electromagnetic environment and mutual interference between EEG analog signals at various locations during the transmission process.

[0004] In addition, the low-frequency circuit in the EEG acquisition device contains interference signals with high-impedance inputs. Even if the transmission line is grounded at one end or both ends in the circuit, it is impossible to avoid interference signals from entering the inner conductor of the transmission cable. At the same time, in the low-frequency band, there is noise current in the transmission cable connecting the patient, which will also interfere with the EEG signals. Summary of the Utility Model

[0005] The utility model provides an electroencephalogram acquisition device with anti-interference function, which can solve the technical problem that the electroencephalogram signals acquired by the existing electroencephalogram acquisition device with anti-interference function are vulnerable to electromagnetic interference in a complex electromagnetic interference environment, resulting in a decrease in the accuracy of the acquired signals.

[0006] In a first aspect, an embodiment of the present application provides an electroencephalogram acquisition device with anti-interference function, including:

[0007] An acquisition module, which responds to an externally input control signal and acquires EEG signals;

[0008] A signal processing module, which is connected to the acquisition module through a shielded transmission cable, and is used to obtain the EEG signals, process the signals and then output them;

[0009] A shielding cover, which is arranged outside the signal processing module and is used to suppress the interference of radiated electromagnetic waves on the EEG signals;

[0010] Wherein, the shielding cover is connected to the shielding layer of the shielded transmission cable by a single-point connection; and the shielding cover is connected to the input end of the signal processing module by a single-point connection.

[0011] In some embodiments, the material of the shielding cover is a ferromagnetic material, and the thickness is 0.3 mm to 1.0 mm.

[0012] In some embodiments, the shielding layer of the shielded transmission cable is a mesh structure woven with metal wires.

[0013] In some embodiments, the shielding layer of the shielded transmission cable is a metal thin film composite layer.

[0014] In some embodiments, in some embodiments, the acquisition module is a disposable non-invasive electroencephalogram sensor.

[0015] In some embodiments, the signal processing module includes a protection circuit and an analog front-end circuit;

[0016] The protection circuit is connected to the acquisition module through the shielded transmission cable for electrostatic and surge protection;

[0017] The analog front-end circuit is connected to the protection circuit for acquiring the electroencephalogram signal collected by the acquisition module, filtering and amplifying it, and then outputting it.

[0018] In some embodiments, the signal processing module further includes an offset amplification circuit; the offset amplification circuit is connected between the acquisition module and the analog front-end circuit, and the input end of the offset amplification circuit is connected to the shielding cover by a single point;

[0019] When the electroencephalogram signal is interfered, the offset amplification circuit is used to provide an offset signal to the analog front-end circuit.

[0020] In some embodiments, the analog front-end circuit is further used to, when the electroencephalogram signal is interfered, filter and anti-alias the electroencephalogram signal according to the acquired offset signal to obtain a feedback signal for canceling the interference in the electroencephalogram signal;

[0021] The offset amplification circuit is further used to acquire the feedback signal and transmit it to the acquisition module to cancel the interference in the electroencephalogram signal.

[0022] In some embodiments, the analog front-end circuit includes an analog front-end chip; the model of the analog front-end chip is ADS1299.

[0023] The anti-interference electroencephalogram (EEG) acquisition device provided by an embodiment of the present application includes an acquisition module and a signal processing module. Among them, the signal processing module is connected to the acquisition module through a shielded transmission cable. A shield is provided outside the signal processing module to suppress radiated electromagnetic interference, and the shield is connected to the shield layer of the shielded transmission cable and the input end of the signal processing module in a single-point connection manner. When acquiring EEG signals, the acquisition module responds to an externally input control signal and starts to acquire the patient's EEG signals, which are output after signal processing such as filtering and amplification by the signal processing module. By setting multiple suppression barriers including the shield and the shielded transmission cable, the present application can effectively suppress the interference of radiated electromagnetic waves on the acquired EEG signals, ensuring the effectiveness and accuracy of EEG signal acquisition. At the same time, the shield is connected to the shielded transmission cable and the input end of the signal processing module in a single-point connection manner, which can help reduce signal distortion while eliminating electromagnetic interference, improve the stability of the acquisition device, and is more universal. Description of the Drawings

[0024] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0025] Figure 1 It is a structural diagram of the anti-interference EEG acquisition device provided by an embodiment of the present application;

[0026] Figure 2 It is a structural diagram of the anti-interference EEG acquisition device provided by another embodiment of the present application.

[0027] Through the above drawings, the clear embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to explain the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Embodiments

[0028] The present application will be further described in detail below in conjunction with the drawings through specific embodiments. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many detailed descriptions are provided to make the present application better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid the core part of the present application being overwhelmed by excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0029] In addition, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean a necessary sequence, unless it is stated otherwise that a certain sequence must be followed.

[0030] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of this application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of the same category and do not limit the number of objects. For example, the first object can be one or multiple. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally represents an "or" relationship between the associated objects before and after. And the "connection" and "coupling" mentioned in this application, unless otherwise specified, both include direct and indirect connection (coupling).

[0031] This application intends to use a current transformer to replace the traditional sampling resistor for sampling the transmitted current and / or transmitted voltage. Based on the electromagnetic induction principle of the current transformer, after the input interface and output interface are connected to the terminal, the current and / or voltage between the input interface and output interface are induced to generate corresponding electrical signals, and the electrical signals are output to the control module to achieve direct sampling of the transmitted current and / or transmitted voltage of the data line in the working state. In the traditional sampling through a sampling resistor, due to the temperature drift phenomenon of the resistance value caused by the ambient temperature or the heat generated by itself, after the change in sampling accuracy is amplified, the deviation value will be amplified sharply, resulting in a decrease in sampling accuracy and the technical problem of being unable to accurately monitor the current value or voltage value.

[0032] The following uses specific embodiments to elaborate in detail on the technical solution of this application and how the technical solution of this application solves the above technical problems. These several specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The following will describe the embodiments of this application in conjunction with the drawings.

[0033] Figure 1 It is a structural diagram of an anti-interference electroencephalogram acquisition device provided by an embodiment of this application. As Figure 1 shown, the anti-interference electroencephalogram acquisition device provided by the embodiment of this application includes an acquisition module 110, a shielded transmission cable 120, a signal processing module 130, and a shield 140.

[0034] In this embodiment, the acquisition module 110 responds to a control signal input externally and acquires electroencephalogram (EEG) signals. In some embodiments, the acquisition module 110 can be a disposable non-invasive EEG electrode, and this EEG electrode also has a shielding function; the acquisition module 110 can also be a disposable non-invasive EEG sensor.

[0035] The signal processing module 130 is connected to the acquisition module 110 through a shielded transmission cable 120, and is used to obtain the EEG signals acquired by the acquisition module 110, perform signal processing such as filtering and amplification on them, and then output, providing a monitoring basis for external medical monitoring devices.

[0036] The shielding case 140 is arranged on the outer layer of the signal processing module 130, and is used to suppress the interference of radiated electromagnetic waves on the EEG signals. When the EEG signals are subject to low-frequency interference, the shielding case 140 can effectively prevent the interference signals from coupling into the inner conductor through the shielding layer.

[0037] In this embodiment, the shielding case 140 is directly connected to the shielding layer of the shielded transmission cable 120 in a single-point connection manner. At the same time, the shielding case 140 and the input end of the signal processing module 130 are also connected in a single-point connection manner. They can choose to connect at the same point or use different points for connection, and finally they are all grounded.

[0038] It should be noted that the single-point connection method achieves the purpose of eliminating electromagnetic interference by suppressing the potential difference. When the shielding layer is grounded at a single point, it will not form a potential difference, and the potentials of all signal lines can be kept consistent, thereby effectively reducing the mutual interference between signal lines. When the potential difference between signal lines decreases, the electromagnetic coupling interference caused by the potential difference between them will also be reduced accordingly, thereby reducing the influence of electromagnetic interference on signals and improving the accuracy and stability of signal transmission. This grounding method is particularly suitable for lines with relatively short lengths, and the induced voltage corresponding to the cable length will not exceed the safety voltage.

[0039] Compared with multi-point grounding, the single-point grounding system is simpler. In multi-point grounding, each signal line needs to be grounded separately, which not only increases the complexity and cost of grounding, but also may introduce new interference due to the potential difference between grounding points, while single-point grounding avoids these problems.

[0040] In practice, compared with multi-point connection, the single-point connection has lower design and manufacturing difficulties and lower costs. During later inspection and maintenance, the problem location can be more quickly and accurately determined, reducing the maintenance cost and workload.

[0041] In summary, the shielding cover 140 is connected to the shielding transmission cable 120 and the input end of the signal processing module 130 in a single-point connection manner, which can eliminate electromagnetic interference, help reduce signal distortion, improve the stability of the acquisition device, simplify the grounding system, reduce the maintenance cost and workload, and is more universal.

[0042] In some embodiments, the shielding transmission cable 120 is a mesh structure made of metal wires woven together, or a metal film composite layer. Through the shielding transmission cable 120, the radiated electromagnetic interference at the acquisition end of the acquisition module 110 can be suppressed, and the shorter the shielding transmission cable 120 is, the better the interference suppression effect is.

[0043] In some embodiments, the material of the shielding cover 140 is a ferromagnetic material with a thickness of 0.3 mm to 1.0 mm. The shielding layer of the ferromagnetic material plays a crucial role in static magnetic shielding. Applying it to medical devices such as electroencephalogram acquisition devices can ensure the reliability of suppressing external magnetic field interference. Commonly used ferromagnetic materials include soft iron, silicon steel, permalloy, etc. These materials are widely used in static magnetic shielding due to their high magnetic permeability. The higher the magnetic permeability of the material and the thicker the cylinder wall, the more significant the shielding effect is.

[0044] Figure 2 This is the structural diagram of the anti-interference electroencephalogram acquisition device provided by another embodiment of the present application. As Figure 2 shown, based on any of the above embodiments, the anti-interference electroencephalogram acquisition device provided by the embodiment of the present application, the signal processing module 130 includes a protection circuit 1301, an offset amplification circuit 1302, and an analog front-end circuit 1303.

[0045] In this embodiment, the input end of the protection circuit 1301 is connected to the acquisition module 110 through the shielding transmission cable 120, and the output end of the protection circuit 1301 is connected to the first input end of the analog front-end circuit 1303. The protection circuit 1301 includes anti-static and surge components, which are used to protect the subsequent circuit against static electricity and surges, so as to prevent the subsequent circuit from being burned out when instantaneous overvoltage occurs, and extend the service life of the acquisition device.

[0046] The input end of the offset amplification circuit 1302 is connected to the output end of the acquisition module 110 and is also connected to the shielding cover 140 at a single point. The output end of the offset amplification circuit 1302 is connected to the second input end of the analog front-end circuit 1303. The offset amplification circuit 1302 is used to generate an offset signal according to the offset voltage and transmit it to the analog front-end circuit 1303 when it detects that the electroencephalogram signal is interfered.

[0047] When it is detected that the EEG signal is not interfered, the analog front-end circuit 1303 is used to obtain the EEG signal collected by the acquisition module 110, filter and amplify it, and then output it. When it is detected that the EEG signal is interfered, the analog front-end circuit 1303 is also used to filter and anti-alias the EEG signal collected from the acquisition module 110 according to the bias signal obtained from the bias amplification circuit 1302, obtain a feedback signal for canceling the interference in the EEG signal, and then reverse-transmit the feedback signal to the acquisition module 110 to cancel the interference signal in the currently collected EEG signal, forming a closed-loop feedback control to ensure the accuracy of the collected EEG signal.

[0048] In some embodiments, the analog front-end circuit 1303 includes an analog front-end chip, and the analog front-end chip of model ADS1299 produced by TI (Texas Instruments) can be selected.

[0049] ADS1299 is a low-noise, multi-channel, simultaneous sampling 24-bit delta-sigma analog-to-digital converter (ADC), which has 8 low-noise programmable gain amplifiers (PGAs) and 8 high-resolution synchronous sampling ADCs, with a very low input reference noise of about 1.0 μVPP (70 Hz bandwidth), and the power consumption per channel is only 5 mW; it also has an internal reference voltage source, oscillator, bias drive amplifier, lead detection and test signal generation, etc.; moreover, it supports single-pole or bipolar power supply operation, and the digital power supply voltage range is 1.8V to 3.6V. With its high integration and excellent performance, ADS1299 is widely used in the field of medical instruments, such as EEG, ECG, auditory evoked potential (EAP), bispectral index (BIS) of electroencephalogram, and sleep research monitoring, etc.

[0050] In summary, the anti-interference EEG acquisition device provided by the embodiments of the present application includes an acquisition module and a signal processing module. Among them, the signal processing module is connected to the acquisition module through a shielded transmission cable, and a shielding cover for suppressing radiated electromagnetic interference is arranged outside the signal processing module, and the shielding cover is connected to the shielding layer of the shielded transmission cable and the input end of the signal processing module in a single-point connection manner. When collecting the EEG signal, the acquisition module responds to an externally input control signal and starts to collect the patient's EEG signal, and outputs it after signal processing such as filtering and amplification by the signal processing module. The present application can effectively suppress the interference of radiated electromagnetic waves on the collected EEG signal by setting multiple suppression barriers of the shielding cover and the shielded transmission cable, ensuring the effectiveness and accuracy of the acquisition of the EEG signal; at the same time, the shielding cover is connected to the shielded transmission cable and the input end of the signal processing module in a single-point connection manner, which can help reduce signal distortion while eliminating electromagnetic interference, improve the stability of the acquisition device, and has better universality.

[0051] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present application, those of ordinary skill in the art, without departing from the purpose of the present application and the scope protected by the claims, can also make several simple deductions, deformations or substitutions according to the idea of the present application, which all fall within the protection scope of the present application.

Claims

1. An anti-interference EEG acquisition device, characterized in that: include: The acquisition module collects the EEG signal in response to the external input control signal; A signal processing module, connected to the acquisition module via a shielded transmission cable, for acquiring the EEG signal, performing signal processing on the signal and then outputting the signal; A shielding cover, provided outside the signal processing module, for suppressing interference of radiated electromagnetic radiation on the EEG signal; Wherein, the shielding cover is connected to the shielding layer of the shielded transmission cable through a single-point connection; and the shielding cover is connected to the input end of the signal processing module through a single-point connection.

2. The anti-interference EEG acquisition device according to claim 1, characterized in that: The shielding cover is made of ferromagnetic material and has a thickness of 0.3 mm to 1.0 mm.

3. The anti-interference EEG acquisition device according to claim 1, characterized in that: The shielding layer of the shielded transmission cable is a mesh structure woven with metal wires.

4. The anti-interference EEG acquisition device according to claim 1, characterized in that: The shielding layer of the shielded transmission cable is a metal film composite layer.

5. The anti-interference EEG acquisition device according to any one of claims 1 to 4, characterized in that: The acquisition module is a disposable non-invasive EEG electrode, and the EEG electrode has a shielding function.

6. The anti-interference EEG acquisition device according to any one of claims 1 to 4, characterized in that: The acquisition module is a disposable non-invasive EEG sensor.

7. The anti-interference EEG acquisition device according to claim 1, characterized in that: The signal processing module includes a protection circuit and an analog front-end circuit; The protection circuit is connected to the acquisition module through the shielded transmission cable for static electricity and surge protection; The analog front-end circuit is connected to the protection circuit, and is used to obtain the EEG signal collected by the collection module, filter and amplify the signal, and then output it.

8. The anti-interference EEG acquisition device according to claim 7, characterized in that: The signal processing module further includes a bias amplifier circuit; the bias amplifier circuit is connected between the acquisition module and the analog front-end circuit, and the input end of the bias amplifier circuit is connected to the shielding cover at a single point; When the electroencephalogram signal is interfered, the bias amplifier circuit is used to provide a bias signal to the analog front-end circuit.

9. The anti-interference EEG acquisition device according to claim 8, characterized in that: The analog front-end circuit is also used to filter and perform anti-aliasing processing on the EEG signal according to the acquired bias signal when the EEG signal is interfered with, so as to obtain a feedback signal for offsetting the interference in the EEG signal; The bias amplifier circuit is also used to obtain the feedback signal and transmit it to the acquisition module to offset the interference in the EEG signal.

10. The anti-interference EEG acquisition device according to claim 7, characterized in that: The analog front-end circuit includes an analog front-end chip; the model of the analog front-end chip is ADS1299.

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