CN117752339A

CN117752339A - device, method and circuit for collecting brain signals of dual-form dry electrode

Info

Publication number: CN117752339A
Application number: CN202311657227.9A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Kingfar International Inc
Current assignee: Kingfar International Inc
Priority date: 2023-12-05
Filing date: 2023-12-05
Publication date: 2024-03-26

Abstract

The invention provides a dual-form dry electrode brain signal acquisition device, an acquisition method and an acquisition circuit, wherein the acquisition device comprises a body, and a forehead She Dianji group and a non-forehead She Dianji group which are arranged on the body; the frontal lobe electrode group comprises a plurality of flaky dry electrodes which are arranged on the frontal lobe brain area of the body corresponding to the user, and the non-frontal lobe electrode group comprises a plurality of needle-shaped dry electrodes which are arranged on the non-frontal lobe brain area of the body corresponding to the user; wherein the frontal brain region comprises at least one of: the forehead lobe brain region and the forehead lobe brain region, and the non-forehead lobe brain region comprises at least one of the following: parietal brain region, occipital brain region, temporal brain region. By the arrangement mode of the dual-form dry electrodes, the characteristics of different regions of the head can be fully considered, the difficulty of brain signal acquisition is effectively reduced, and the signal quality of brain signal acquisition is improved. The design is not only beneficial to improving the accuracy and reliability of brain signal acquisition, but also can improve the comfort and participation of the testee.

Description

device, method and circuit for collecting brain signals of dual-form dry electrode

Technical Field

The invention relates to the field of electroencephalogram equipment, in particular to a device, a method and a circuit for collecting brain signals of a dual-form dry electrode.

Background

An Electroencephalogram (EEG) is a type of bioelectric signal that records brain activity. It detects and measures electrical activity of brain neurons by placing electrodes on the scalp. EEG is widely applied to the fields of brain science research, clinical diagnosis, nerve engineering and the like. It may provide important information about brain function and activity, such as sleep status, conscious level, seizures, cognitive processes, etc. Clinically, EEG is commonly used to diagnose and monitor epilepsy, brain injury, sleep disorders, and the like.

at present, in the existing electroencephalogram signal acquisition device, the electrode is commonly arranged in a manner of acquiring the electroencephalogram signal based on a sheet-shaped dry electrode in a single form, if the sheet-shaped dry electrode is inadequately attached to the scalp, the acquisition effect of the electroencephalogram signal can be adversely affected, the attenuation or distortion of the electroencephalogram signal can be caused by poor attachment, and even the electroencephalogram signal cannot be accurately acquired, so that the subsequent signal processing and analysis work can be affected.

Disclosure of Invention

In view of the above, embodiments of the present invention provide a dual-modality dry electrode brain signal acquisition device, an acquisition method, and an acquisition circuit, so as to eliminate or improve one or more drawbacks of the prior art.

the technical scheme of the invention is as follows:

In a first aspect, the present invention provides a dual modality dry electrode brain signal acquisition device comprising a body and a set of She Dianji and a set of She Dianji non-frontal electrodes disposed on the body; the frontal lobe electrode group comprises a plurality of flaky dry electrodes which are arranged on the frontal lobe brain region of the body corresponding to a user, and the non-frontal lobe electrode group comprises a plurality of needle-shaped dry electrodes which are arranged on the non-frontal lobe brain region of the body corresponding to the user; wherein the frontal brain region comprises at least one of: a frontal lobe brain region, a posterior lobe brain region, the non-frontal lobe brain region comprising at least one of: parietal brain region, occipital brain region, temporal brain region.

in some embodiments, the body is a unitary rigid structure; or, the body is an integral elastic cap structure.

In some embodiments, the sheet-like dry electrode is a passive dry electrode, the sheet-like dry electrode is in a wafer structure with a preset thickness, and the substrate is red copper, the plating layer is silver, or the substrate is red copper, the plating layer is silver and silver chloride.

in some embodiments, the needle-shaped dry electrode is a passive dry electrode, the needle-shaped dry electrode is a spring needle component with a single collection point, the spring needle component comprises a thimble, a sleeve and a spring arranged in the sleeve, the thimble is arranged in the sleeve through the spring, the thimble has a working stroke capable of extending and retracting along the axis of the sleeve, the substrate of the needle-shaped dry electrode is red copper, and the plating layer is silver.

In some embodiments, the needle-shaped dry electrode is a passive dry electrode, and the needle-shaped dry electrode is a claw-shaped electrode with a plurality of collecting points, and the electrode comprises a base and a plurality of electrode needles arranged on the base, wherein each electrode needle is uniformly distributed on one side of the base.

in some embodiments, the patch-like dry electrode and/or the needle-like dry electrode is an active dry electrode, which is disposed on a circuit board containing a voltage follower circuit.

in some embodiments, in the case that the needle-shaped dry electrode is an active dry electrode, the needle-shaped dry electrode is a claw-shaped electrode with a plurality of collection points, and the claw-shaped electrode comprises a base and a plurality of electrode needles arranged on the base, wherein each electrode needle is uniformly distributed on one side of the base, and the base is welded on the circuit board.

In some embodiments, the needle-like dry electrode is a single collection point spring needle assembly having a maximum contact resistance of 50mΩ at a working height, a spring force of 10 g-30 g at a normal working height, a working stroke of 3.5mm±0.02, and a working height of 6.5mm±0.02.

in some embodiments, one of the patch-like dry electrodes of the several patch-like dry electrodes comprised by the frontal lobe electrode group is a GND electrode.

In some embodiments, the body of the integral hard structure comprises a first half ring corresponding to a frontal lobe brain region, a second half ring corresponding to a occipital lobe brain region, and a third half ring corresponding to a parietal lobe brain region and/or a temporal lobe brain region, the three half rings of the body are connected to each other to form an integral structure, the group She Dianji of the forehead is disposed on an inner side surface of the first half ring, and the inner side surfaces of the second half ring and/or the third half ring are provided with the group She Dianji of the forehead; and at least two of the first semi-ring, the second semi-ring and the third semi-ring are arranged to be of a telescopic structure.

In a second aspect, the present invention provides a brain signal acquisition method, where the method adopts the above-mentioned dual-modality dry electrode brain signal acquisition device, and the method includes:

brain signals were acquired by the plate-like dry electrodes of the She Dianji set and the needle-like dry electrodes of the non-She Dianji set placed on the head of the subject and adjusted in place to bring the electrodes into close contact with the head of the subject.

in some embodiments, the method further comprises:

Using an ESD protection module to carry out electrostatic discharge protection on brain signals collected by the sheet dry electrodes of the She Dianji group and the needle dry electrodes of the non-She Dianji group;

Filtering high-frequency noise of the brain signal by using a low-pass filter;

Using a programmable gain amplifier to enlarge the brain signal after filtering high-frequency noise;

Converting the amplified brain signal into a digital signal using an analog-to-digital converter;

and transmitting the brain signals after being converted into digital signals to a microcontroller unit.

In some embodiments, the sheet-like dry electrode and/or the needle-like dry electrode is an active dry electrode, the method further comprising:

the voltage follower circuit is used for following the potential difference between the flaky dry electrodes of the forehead She Dianji group and/or the needle-shaped dry electrodes of the non-forehead She Dianji group and the scalp, and outputting a voltage signal identical to the potential difference, so that the active electrode is in a normal working state.

In a third aspect, the present invention provides a brain signal acquisition circuit, where the acquisition circuit is configured to implement the foregoing brain signal acquisition method, and the acquisition circuit includes:

the ESD protection modules are respectively connected with electrodes of the She Dianji group and the She Dianji non-group and are used for performing electrostatic discharge protection on brain signals acquired by the electrodes;

a plurality of low-pass filters, each of which is connected with each electrode of the She Dianji group and the She Dianji non-group respectively, for filtering out high-frequency noise of the brain signals;

the programmable gain amplifiers are respectively connected with the corresponding low-pass filters directly or through a multiplexer and are used for amplifying the brain signals after the high-frequency noise is filtered;

the analog-to-digital converters are respectively connected with the corresponding programmable gain amplifiers and are used for converting the amplified brain signals into digital signals;

The microcontroller unit is connected with each analog-to-digital converter and is used for receiving the brain signals which are sent by the analog-to-digital converters and are converted into digital signals through a communication protocol; the brain signal is also used for carrying out data reduction on the brain signal converted into the digital signal so as to restore the brain signal into an original sampling value; the method is also used for judging whether to carry out filtering processing on the brain signals converted into digital signals and carry out filtering processing on the brain signals so as to further reduce noise or interference; and the brain signals are stored or transmitted to an upper computer.

in some embodiments, the sheet-like dry electrode and/or the needle-like dry electrode is an active dry electrode, the acquisition circuit further comprising: the voltage follower circuits are arranged on the circuit board connected with the electrodes of the She Dianji group and the She Dianji group and used for following the potential difference between the electrodes and the scalp and outputting a voltage signal identical to the potential difference so that the active electrode is in a normal working state.

According to the contact characteristics of different regions of the head, the bimodal dry electrode brain signal acquisition device provided by the embodiment of the invention introduces a bimodal dry electrode, and a sheet dry electrode is arranged in a region with fewer hairs or without hairs (such as a frontal lobe brain region) to acquire brain signals of the region, and the sheet dry electrode is arranged to be in more direct contact with the scalp, so that the stability and sensitivity of the signals are improved, and the brain signals of the region are effectively acquired. The needle-shaped dry electrode is arranged in the area with more hair (such as a non-frontal lobe brain area) to collect brain signals in the area, the needle-shaped dry electrode can penetrate hair to be contacted with scalp more easily, interference of the hair on signal contact is reduced, meanwhile, contact stability of the electrode and the scalp can be kept better, and the method is beneficial to improving signal quality of brain signal collection in the area.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.

it will be appreciated by those skilled in the art that the objects and advantages that can be achieved with the present invention are not limited to the above-described specific ones, and that the above and other objects that can be achieved with the present invention will be more clearly understood from the following detailed description.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate and together with the description serve to explain the application. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the application. Corresponding parts in the drawings may be exaggerated, i.e. made larger relative to other parts in an exemplary device actually manufactured according to the present application, for convenience in showing and describing some parts of the present application. In the drawings:

Fig. 1 is a schematic diagram of a dual-modality dry electrode brain signal acquisition device using a soft structure according to an embodiment of the present invention.

fig. 2 is a top view of a dual modality dry electrode brain signal acquisition device employing a rigid structure in accordance with another embodiment of the present invention.

fig. 3 is a right body view of a brain signal acquisition device using a rigid structure dual modality dry electrode in accordance with another embodiment of the present invention.

fig. 4 is a perspective view of a telescopic dual-modality dry electrode brain signal acquisition device according to an embodiment of the present invention.

fig. 5 is a schematic diagram of the structure of the forehead She Dianji group and the sheet-shaped dry electrode according to an embodiment of the invention.

Fig. 6 is a schematic diagram of the structure of the pillow She Dianji set (or top leaf electrode set) and the needle-shaped dry electrode according to an embodiment of the invention.

Fig. 7 is a schematic diagram of an electrode arrangement of a brain signal acquisition device according to an embodiment of the invention.

fig. 8 is a phantom database of a brain signal acquisition device according to an embodiment of the invention.

Fig. 9 is a schematic view of a spring needle assembly used for the needle-like dry electrode in an embodiment of the present invention.

Fig. 10 is a schematic view of a claw electrode used as a needle-like dry electrode according to another embodiment of the present invention.

fig. 11 is a schematic view of a needle-like dry electrode according to another embodiment of the present invention.

Fig. 12 is a block diagram of a brain signal acquisition method according to an embodiment of the present invention.

Fig. 13 is a flowchart of a brain signal acquisition method according to an embodiment of the invention.

Fig. 14 is an overall circuit diagram of a brain signal acquisition circuit using passive electrodes in an embodiment of the invention.

Fig. 15 is an overall circuit diagram of a brain signal acquisition circuit using active electrodes in an embodiment of the present invention.

reference numerals:

1. A first half ring; 2. a second half ring; 3. a third half ring; group 4-1, forehead She Dianji; 41. a sheet-like dry electrode; 4-2, pillow She Dianji groups; 42. a needle-like dry electrode; 42A, spring needle assembly; 42A-1, thimble; 42A-2, a cannula; 42A-3, springs; 42B, claw-like electrodes; 42B-1, a base; 42B-2, electrode needle; 43. a circuit board; 4-3, top leaf electrode group.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments and the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent. The exemplary embodiments of the present invention and the descriptions thereof are used herein to explain the present invention, but are not intended to limit the invention.

it should be noted here that, in order to avoid obscuring the present invention due to unnecessary details, only structures and/or processing steps closely related to the solution according to the present invention are shown in the drawings, while other details not greatly related to the present invention are omitted.

it should be emphasized that the term "comprises/comprising" when used herein is taken to specify the presence of stated features, elements, steps or components, but does not preclude the presence or addition of one or more other features, elements, steps or components.

It is also noted herein that the term "coupled" may refer to not only a direct connection, but also an indirect connection in which an intermediate is present, unless otherwise specified.

hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

in view of the defect of poor brain signal acquisition effect existing in the prior art that a brain signal acquisition device with a single form is used, the invention provides a brain signal acquisition device with a double-form dry electrode, an acquisition method and an acquisition circuit.

In a first aspect, the invention provides a dual-modality dry electrode brain signal acquisition device, comprising a body and a forehead She Dianji group 4-1 and a non-forehead She Dianji group arranged on the body; the forehead She Dianji set 4-1 includes a plurality of sheet-shaped dry electrodes 41 mounted on the body in the frontal lobe area corresponding to the user, and the non-frontal lobe electrode set includes a plurality of needle-shaped dry electrodes 42 mounted on the body in the non-frontal lobe area corresponding to the user. Wherein the frontal brain region comprises at least one of: a frontal lobe brain region, a posterior lobe brain region, the non-frontal lobe brain region comprising at least one of: parietal brain region, occipital brain region, temporal brain region.

Among these, the frontal, parietal, occipital and temporal lobes are one of the common EEG signal acquisition areas.

As the frontal lobe brain region, the frontal lobe is located in the anterior part of the brain, including the frontal lobe and the posterior lobe. The frontal lobe is the front of the frontal lobe, adjacent to the lower frontal margin, and involves functions such as emotion, decision, cognitive control, and social behavior. The posterior frontal lobe is the posterior part of the frontal lobe and relates to functions such as visual information processing and spatial cognition. As a non-frontal lobe brain region, the parietal lobe is located in the central region of the brain, and involves functions such as sensory information processing and attention. Occipital lobe is located at the rear of brain, and relates to functions such as visual information processing and space navigation. The temporal lobe is located on the lateral side of the brain and involves auditory information processing, language and memory functions.

According to the contact characteristics of different regions of the head, the bimodal dry electrode brain signal acquisition device provided by the embodiment of the invention introduces a bimodal dry electrode, and the sheet dry electrode 41 is arranged in a region with fewer hairs or without hairs (such as a frontal lobe brain region or a frontal lobe brain region thereof) to acquire brain signals of the region, and the sheet dry electrode 41 is arranged to be in more direct contact with the scalp, so that the stability and the sensitivity of signals are improved, and the brain signals of the region are effectively acquired. The needle-shaped dry electrode 42 is arranged in the area with more hair (such as the parietal brain area, the occipital brain area and the temporal brain area) to collect brain signals of the area, the scalp can be more easily contacted by penetrating the hair through the needle-shaped dry electrode 42, the interference of the hair on the signal contact is reduced, meanwhile, the contact stability of the electrode and the scalp can be better kept, and the improvement of the signal quality of the brain signal collection in the brain area is facilitated.

Compared with the frontal lobe brain region still collecting needle-shaped dry electrodes, the collecting device provided by the embodiment of the invention uses the sheet-shaped dry electrodes in the frontal lobe brain region, so that the tested wearing comfort is higher, the fixation of the sheet-shaped dry electrodes is firmer, and the signal collection is more stable.

In the embodiment, through the arrangement mode of the dry electrodes in the double forms, the characteristics of different areas of the head can be fully considered, the difficulty of brain signal acquisition is effectively reduced, and the signal quality of brain signal acquisition is improved. The design is not only beneficial to improving the accuracy and reliability of brain signal acquisition, but also can improve the comfort and participation of the testee, thereby better meeting the demands of scientific research and clinical application.

The brain signal acquisition device has the advantages that the brain signal acquisition device can be flexibly adjusted according to the characteristics of different regions of the head, so that the difficulty of brain signal acquisition is reduced, and the quality and reliability of signals are improved. The design is expected to be widely applied in the field of brain signal acquisition, provides more reliable and accurate brain signal data for the fields of scientific research, medical treatment and the like, and is beneficial to promoting the development and progress of the related fields.

in some embodiments, the body is a one-piece rigid structure or a one-piece resilient cap structure.

For example, the body in the embodiment shown in fig. 1 adopts a soft integral elastic cap structure, wherein the large disc of the frontal brain region represents a sheet-shaped dry electrode, and the small disc electrode of the non-frontal brain region represents a needle-shaped dry electrode (the electrode needle is positioned at the side contacted with the scalp of the model and is not shown); the body in the embodiment of fig. 2-4 is of one piece rigid construction.

The electrode cap (body) of the electroencephalogram device can use various soft materials or forms to improve wearing comfort and signal acquisition effects, such as silica gel materials, cloth, elastic materials and the like. The silica gel has softness and elasticity, can laminate with the head profile, provides good wearing comfort. Meanwhile, the silica gel material also has the characteristics of durability and easy cleaning. Soft fabric or foam materials can be used to make electrode caps that provide soft fit and ventilation, reducing discomfort to the wearer. The electrode cap made of the material with certain elasticity can provide certain elasticity under the condition of keeping stability, and is suitable for people with different head circumferences. Regardless of the soft material or morphology selected, the key is to ensure good fit of the electrode cap to the head, maintain stable contact, and provide a comfortable wearing experience. The electrode cap of the electroencephalogram device has a shape including, but not limited to, a mesh cap, a closed helmet type, a wire type, or the like.

The electrode cap (body) of the electroencephalogram device can also be made of hard materials, the electrode group can be better fixed and supported by the hard materials, the possibility of electrode position movement caused by head movement and other reasons is reduced, and therefore the stability of signal acquisition is improved. The electrode cap made of hard materials can better keep consistency of shape and size, so that repeatability of signal acquisition is improved, and comparison and analysis of experimental data are facilitated. The hardness material can be adjusted through modes such as flexible or pressurization to adapt to the wearing demand of different head types, improve the comfort level of wearing. Compared with soft materials, the surface of the hard materials is easier to clean, the possibility of bacteria breeding is reduced, and therefore the wearing sanitation is improved.

As shown in fig. 1 and 2-4, in some embodiments, the non-frontal lobe electrode set includes a top lobe electrode set 4-3 and a pillow She Dianji set 4-2 (temporal lobe electrode set may be distributed in any one or more of the electrode sets), the top lobe electrode set 4-3 and the pillow She Dianji set 4-2 each include a plurality of needle-shaped dry electrodes 42, the top lobe electrode set 4-3 is mounted to a top lobe brain region of the body corresponding to a user, and the pillow She Dianji set 4-2 is mounted to a occipital brain region of the body corresponding to a user.

The electroencephalogram device provided by the embodiment of the invention is provided with the acquisition electrodes in the frontal lobe brain area, and also provided with the acquisition electrodes in the parietal lobe brain area, the occipital lobe brain area and the temporal lobe brain area, so that brain signals of front, middle and rear three main areas of the brain can be acquired, and the omnidirectional brain signal acquisition is realized. The brain signals in different areas have different frequency and amplitude characteristics, so that the spatial-temporal resolution of the brain signals can be improved through multi-area acquisition, the change of brain function activities can be reflected more accurately, and deep exploration of brain functions and relevant mechanisms is facilitated.

the multi-region acquisition can also be used for comparison analysis, such as the comparison of frontal lobe brain region and parietal lobe brain region, occipital lobe brain region and temporal lobe brain region, which is helpful for studying the interaction and coordination between different brain regions. Brain signals in different areas are distinguished, mixed signals of other muscles, eye movements and the like can be reduced through multi-area acquisition, and the purity and reliability of acquisition are improved.

The electrodes of the brain signal acquisition device in the embodiment of the invention are all dry electrodes, and compared with wet electrodes and water for acquiring brain signals, gel and saline are respectively required to be used as conductive media, the dry electrodes can acquire brain signals without any conductive media, so that the dry electrodes are more severely required in material selection and morphology. The wet electrode and the water electrode are connected with the conductive medium, so that the brain electrical contact impedance is reduced, the noise of the input analog signal is reduced, and the brain signal can be acquired better. And the dry electrode is according to the formula of contact resistance, as follows:

Wherein:

The K value is a material-dependent coefficient;

F represents the contact pressure;

m represents a contact form, m=0.5 in point contact, m=0.5 to 0.7 in line contact, and m=1 in surface contact.

The electroencephalogram device in the embodiment of the invention can use an active electrode or a passive electrode. The active electrode is integrated with an amplifier, which can amplify brain signals, inhibit noise interference and improve signal to noise ratio.

Passive electrodes are generally less costly than active electrodes because they do not require additional circuitry and power supplies. The passive electrode has simple structure and is relatively convenient to use.

In some embodiments, the sheet-shaped dry electrode 41 is a passive dry electrode, and the sheet-shaped dry electrode 41 is in a wafer structure with a predetermined thickness, and the substrate is red copper, the plating layer is silver, or the substrate is red copper, and the plating layer is silver-plated silver chloride. The electrode is designed in a circular plate-shaped structure, and is convenient to fix and contact on the surface of the skin, so that stable acquisition of signals is realized. The electrode has a predetermined thickness, which helps to ensure the quality and stability of the contact between the electrode and the skin. Silver is an excellent conductive material, which is beneficial to ensuring good signal transmission and contact quality. In some cases, a silver-plated silver chloride plating structure may be employed in order to further improve the conductivity and corrosion resistance.

in some embodiments, as shown in fig. 9 and 10, the needle-shaped dry electrode 42 is a passive dry electrode, and the structure thereof can take various forms to achieve stable bioelectric signal acquisition and minimize interference with the tested object.

For example, in the embodiment shown in FIG. 9, the needle-like dry electrode 42 is a single pick-up point spring needle assembly 42A comprising a needle 42A-1, a cannula 42A-2 and a spring 42A-3 disposed within the cannula 42A-2, the needle 42A-1 being disposed within the cannula 42A-2 by the spring 42A-3, the needle 42A-1 having a working stroke that is retractable along the axis of the cannula 42A-2. The structural design is beneficial to adapting to the shapes of different skin surfaces and the size of the head circumference of a human body, so that better contact quality is realized. The needle-shaped dry electrode 42 is made of red copper as a substrate and silver as a plating layer. Red copper has good mechanical and electrical conductivity as a substrate, and silver plating helps to ensure good signal transmission quality.

Further, the thimble 42A-1 may be disposed at an angle of inclination or swing, such as 1-5, alternatively 3, relative to the fixedly disposed thimble 42A-2. The needle-like dry electrode 42 is better adapted to the curve and shape of the skin surface by having a certain angle of inclination or oscillation of the needle-like dry electrode 42A-1, thereby improving the stability and quality of contact. This design can have a positive impact on the signal acquisition effect in practical applications, especially in cases where long wear is required, and can reduce electrode displacement or poor contact problems due to motion or other factors. The swing design is favorable for improving the stability and accuracy of signal acquisition, and meets the requirements of the biomedical field and the like on the signal acquisition precision.

further, the needle-shaped dry electrode 42 is a spring needle assembly 42A with a single collection point, the maximum contact resistance at the working height is 50mΩ, the elastic force at the normal working height is 10 g-30 g, the working stroke is 3.5mm±0.02, and the working height is 6.5mm±0.02.

For another example, in the embodiment shown in fig. 10, the needle-shaped dry electrode 42 is a passive dry electrode, and the needle-shaped dry electrode 42 is a claw-shaped electrode 42BB with a plurality of collection points, which includes a base 42B-1 and a plurality of electrode needles 42B-2 disposed on the base 42B-1, and each of the electrode needles 42B-2 is uniformly distributed on one side of the base 42B-1. The design integrates a plurality of electrode pins 42B-2 on one base 42B-1, which is convenient for electrode arrangement and can realize multipoint acquisition, thereby improving the spatial resolution of signal acquisition.

the design of the active dry electrode can effectively reduce noise interference caused by factors such as the electrode and a connecting wire, and can also provide the functions of amplifying and adjusting signals, which are helpful for improving the acquisition quality of bioelectric signals. The active electrode has lower input impedance, so that the contact impedance between the electrode and the skin can be reduced, and the sensitivity of signal acquisition is improved. Due to the design of the internal amplifier, the active electrode has high anti-interference capability against interference from external power sources and the environment.

In some embodiments, the sheet-like dry electrode 41 and/or the needle-like dry electrode 42 are active dry electrodes, the sheet-like dry electrode 41 and/or the needle-like dry electrode 42 being provided on a circuit board 43 containing a voltage follower circuit. The voltage follower circuit on the circuit board 43 can help amplify and process the signal during signal acquisition, thereby improving the signal-to-noise ratio and ensuring signal accuracy. The voltage follower circuit can also be used for ensuring the stability of signals under different conditions, for example, when different skin resistances or environmental interference change, the working parameters can be automatically adjusted to ensure the stability of signal acquisition.

In the embodiment shown in fig. 11, in the case where the needle-shaped dry electrode 42 is an active dry electrode, the needle-shaped dry electrode 42 is a claw-shaped electrode 42B with a plurality of collection points, which includes a base 42B-1 and a plurality of electrode needles 42B-2 disposed on the base 42B-1, each of the electrode needles 42B-2 is uniformly distributed on one side of the base 42B-1, and the base 42B-1 is soldered on the circuit board 43. The design can realize a plurality of acquisition points, and improves the spatial resolution and accuracy of signal acquisition. Each electrode pin 42B-2 may be considered an independent acquisition channel so that bioelectrical activity of multiple signal sources may be acquired simultaneously. The welded fixation of the base 42B-1 can ensure the stability and reliability of the electrode, thereby reducing signal distortion or interference caused by electrode displacement or poor contact.

Further, the circuit board 43 is shaped to accommodate at least one claw-like electrode 42B, and at least one fixing hole (alternatively, two symmetrical arrangements for firm fixation) is also required to be designed on the circuit board 43. The circuit board 43 may be provided with pads 432 or a plug-in port for connecting signal lines, in addition to the voltage follower circuit 431.

the output voltage of the voltage follower is the same as the input voltage, that is, the voltage amplification of the voltage follower is constantly less than and close to 1. A significant feature of voltage followers is the high input impedance and the low output impedance, which is generally easy to achieve with input impedances up to several mega ohms. The output impedance is low, typically up to a few ohms, or even lower. The reason for using a voltage follower to design an electroencephalogram active dry electrode is that the impedance when a dry electrode of some materials is in contact with the scalp is very high compared to a water electrode and a wet electrode, and when a dry electrode is used, the excessive inherent impedance can cause the electrode to be in a Lead off state. The impedance can be reduced using a voltage follower circuit.

In some embodiments, one of the patch-like dry electrodes 41 of the number of patch-like dry electrodes 41 included in the set She Dianji 4-1 is a GND electrode. One of the patch electrodes 41 is designated as a GND (ground) electrode, such as the front most intermediate electrode. The GND electrode functions to provide a reference potential or as a place of a circuit to compare and measure signals collected by other electrodes.

The GND electrode may share the same physical contact position as the other sheet-like dry electrode 41, for example, placed at a specific point on the scalp. By designating one sheet-like dry electrode 41 as a GND electrode, signals collected by other electrodes are compared with this electrode as a reference, and the potential difference with respect to the ground is calculated, thereby obtaining a more accurate measurement result. In electroencephalogram (EEG) and like applications, the correct setting of the GND electrodes is critical to obtaining an accurate signal. It helps to reduce common mode noise between the electrodes and provides a stable reference point, making the measurement more reliable and comparable.

The forehead She Dianji group 4-1 in the embodiment of the present invention may be provided with 5 sheet-like dry electrodes 41, wherein 4 sheet-like dry electrodes 41 are used as brain electrical activity electrodes and 1 sheet-like dry electrode 41 is used as GND electrode of brain electrical activity. The top leaf electrode group 4-3 and the pillow She Dianji group 4-2 may be provided with 4 needle-like dry electrodes 42. Of course, the needle-shaped dry electrode 42 described herein may employ the structure of the claw-shaped electrode 42B described above, i.e., one needle-shaped dry electrode 42 may also include a plurality of electrode needles 42B-2.

The number of the electrodes in the embodiment of the invention is adjusted according to the brain region to be acquired, not limited to a fixed number, and the electrode positions can be symmetrically arranged according to the international 10-20 system electrode placement method shown in fig. 7.

In some embodiments, the body is a rigid structure, and may be designed to be a telescopic structure in order to increase its applicability to different people. The body comprises a top lobe brain region, a occipital lobe brain region, a first semi-ring 1 of a temporal lobe brain region, a second semi-ring 2 corresponding to the occipital lobe brain region and a third semi-ring 3 corresponding to the top lobe brain region and/or the temporal lobe brain region, wherein the three semi-rings of the body are mutually connected to form an integrated structure, and a telescopic structure is arranged between at least two of the first semi-ring 1, the second semi-ring 2 and the third semi-ring 3.

Optionally, the inner side of the second half ring 2 and/or the third half ring 3 is provided with the non-set She Dianji of groups. Further, the forehead She Dianji group 4-1 is arranged on the inner side surface of the first half ring 1, the pillow She Dianji group 4-2 is arranged on the inner side surface of the second half ring 2, and the top leaf electrode group 4-3 is arranged on the inner side surface of the third half ring 3; the first semi-ring 1 and the second semi-ring 2 form a closed ring shape, the third semi-ring 3 is intersected with the first semi-ring 1 or the second semi-ring 2, and the first semi-ring 1 and the third semi-ring 3 are both arranged to be telescopic structures relative to the second semi-ring 2.

In the above embodiment, the body is a hard structure for fixing the electrode and fitting it tightly on the scalp for signal acquisition. In the design of the body, the first half ring 1 and the third half ring 3 are arranged to intersect with the second half ring 2, and the first half ring 1 and the third half ring 3 are designed to be telescopic structures. The telescopic structure can adopt a plugging and locking structure with a certain depth. The plugging and locking structure is usually designed into convex-concave shapes which are mutually matched, and when the two parts of structures are inserted to a certain depth, the locking device can automatically fix the two parts together, so that the body is ensured not to be loosened or shifted due to external force. The design is simple and easy to implement, and can provide stable support and comfortable experience in the wearing process. This makes the body adaptable to people of different head sizes and shapes, thereby improving the applicability and comfort of the body. In addition, the telescopic structure of the first half ring 1 and the third half ring 3 also helps to alleviate the feeling of pressure on the head when worn.

Alternatively, the above-mentioned body may be designed in the dimensions of the first half ring 1, the second half ring 2, and the third half ring 3, referring to fig. 8, and fig. 8 is a database of mannequins, where the body is designed in the dimensions to cover the head circumference data of different sexes, different ages, and the like.

in a second aspect, the present invention provides a brain signal acquisition method, as shown in fig. 12, where the method uses the foregoing dual-modality dry electrode brain signal acquisition device, and the method includes:

S10: brain signals were acquired by the plate-like dry electrodes of the She Dianji set and the needle-like dry electrodes of the non-She Dianji set placed on the head of the subject and adjusted in place to bring the electrodes into close contact with the head of the subject.

The brain signal acquisition method uses sheet-like dry electrodes in the frontal lobe electrode group and needle-like dry electrodes in the non-frontal She Dianji group. This configuration can effectively acquire brain signals, and by closely fitting the electrodes to the head of the subject, the quality and accuracy of the signals can be improved.

In some embodiments, as shown in fig. 13, the method further comprises:

s20: using an ESD protection module to carry out electrostatic discharge protection on brain signals collected by the sheet dry electrodes of the She Dianji group and the needle dry electrodes of the non-She Dianji group; this step can effectively prevent the influence of the interference generated by the electrostatic discharge on the acquisition and processing of brain signals.

S30: filtering high-frequency noise of the brain signal by using a low-pass filter; this step can effectively remove high frequency noise present in brain signals, thereby improving the quality and accuracy of the signals.

S40: using a programmable gain amplifier to enlarge the brain signal after filtering high-frequency noise; this step may amplify the signal to a suitable range so that it can be processed by the digital signal processing unit.

S50: converting the amplified brain signal into a digital signal using an analog-to-digital converter; this step converts the analog signal to a digital signal for subsequent digital signal processing.

s60: and transmitting the brain signals after being converted into digital signals to a microcontroller unit. This step transmits the digital signal to the microcontroller unit for subsequent signal processing, analysis and application.

The above-described method helps to improve signal quality, reduce the effects of interference and noise, and enable signals to be processed and applied efficiently. It is appreciated that the specific implementation details may vary from application scenario to application scenario and from system to system scenario.

In some embodiments, to be suitable for use with an active electrode, the sheet-like dry electrode and/or the needle-like dry electrode is an active dry electrode, the method further comprising:

The voltage follower circuit is used for following the potential difference between the flaky dry electrode of the forehead She Dianji group and the needle-shaped dry electrode of the non-forehead She Dianji group and the scalp, and outputting a voltage signal identical to the potential difference, so that the active electrode is in a normal working state.

In the above embodiments, the active electrode is mainly used to reduce the impedance between the electrode and the scalp and improve the driving capability. The active electrode is provided with a voltage follower circuit which can measure the potential difference of the input circuit and output a voltage signal of the same magnitude. The voltage follower circuit can continuously follow and output a voltage signal equal to the potential difference. This maintains the stability and accuracy of the active electrode to ensure proper operation of the desired function. For example, the method can automatically adjust the operating parameters to ensure stability of signal acquisition even when different skin resistances or environmental disturbances vary.

In a third aspect, the present invention provides a brain signal acquisition circuit for implementing the aforementioned brain signal acquisition method, as shown in fig. 14 and 15, the acquisition circuit comprising: a plurality of ESD protection modules, a plurality of low pass filters, a plurality of Programmable Gain Amplifiers (PGAs), a plurality of analog-to-digital converters (ADCs), and a microcontroller unit (MCU), etc. In other words, each electrode is provided with an ESD protection module, a low pass filter, a Programmable Gain Amplifier (PGA), and an analog-to-digital converter (ADC).

Optionally, each ESD protection module is respectively connected with each electrode of the She Dianji group and the non-She Dianji group, and is used for performing electrostatic discharge protection on brain signals collected by the electrodes. Specifically, the brain signals collected by the electrodes of the She Dianji, she Dianji and top leaf electrode groups are electrostatically protected using an ESD (electrostatic discharge) protection module. The ESD protection module is used for preventing the electrostatic discharge from interfering or damaging brain signals collected by the electrodes.

Optionally, each low-pass filter is connected to each electrode of the She Dianji group and the non-She Dianji group respectively, and is used for filtering high-frequency noise of the brain signals. Specifically, the brain signal is filtered using a low pass filter to filter out high frequency noise. The high frequency noise may be interference from environmental interference or from the device itself, which may affect the quality and accuracy of the brain signal. By using a low pass filter, high frequency noise can be filtered out, preserving the effective brain signal in the lower frequency range.

Optionally, each programmable gain amplifier is directly connected with the corresponding low-pass filter or connected with the corresponding low-pass filter through a multiplexer, and is used for enlarging the brain signal after filtering high-frequency noise; specifically, a programmable gain amplifier is used to amplify the brain signal after filtering out the high frequency noise. The programmable gain amplifier can adjust the amplification of the signal as needed to ensure that the range of brain signal amplitudes is suitable for subsequent processing and analysis. The amplified signal may be better provided to a subsequent digital signal processing unit.

Optionally, each analog-to-digital converter is connected with a corresponding programmable gain amplifier, and is used for converting the amplified brain signals into digital signals; specifically, the amplified brain signal is converted into a digital signal using an analog-to-digital converter. Analog-to-digital converters convert continuous analog signals to discrete digital signals for storage, transmission, and digital signal processing. After being converted into digital signals, the brain signals can be conveniently subjected to data analysis, feature extraction and other operations.

The microcontroller unit is connected with each analog-to-digital converter and is used for receiving the brain signals which are sent by the analog-to-digital converter and are converted into digital signals through a communication protocol; the brain signal is also used for carrying out data reduction on the brain signal converted into the digital signal so as to restore the brain signal into an original sampling value; the method is also used for judging whether to carry out filtering processing on the brain signals converted into digital signals and carry out filtering processing on the brain signals so as to further reduce noise or interference; the brain signal is also used for storing or transmitting the brain signal to an upper computer; the microcontroller unit is a control unit that integrates a processor and other functions for receiving, processing and managing brain signal data. The brain signal data can be monitored, stored, analyzed and displayed in real time by the microcontroller unit.

the brain signal acquisition circuit may also include a power supply circuit for providing a desired power supply. The power supply circuit comprises an overvoltage protection circuit, a charging circuit, a digital power supply circuit and an analog power supply circuit.

The power supply circuit can integrate power supply equipment such as an adapter or a battery and the like to provide a stable direct current power supply for the brain signal acquisition device. Thus, the brain signal acquisition device can normally operate and perform operations such as acquisition, processing and the like. The power supply circuit generally further has a power management function, and can control and manage power supply, such as charging, power monitoring, power saving mode, etc., so as to improve durability and use convenience. The power supply circuit can also comprise a voltage and current protection circuit, so that the brain signal acquisition device can be prevented from being influenced by excessively high or excessively low power supply in the use process, and the safety of a user can be ensured.

In some embodiments, for application to the active electrode, the sheet-like dry electrode and/or the needle-like dry electrode is an active dry electrode, and the brain signal acquisition circuit further includes a plurality of voltage follower circuits, where each voltage follower circuit is disposed on a circuit board to which each electrode of the She Dianji group and the non-She Dianji group is connected, and is configured to adjust the output voltage according to a change in the brain signal acquired by the electrode.

As shown in fig. 15, the brain signal acquisition circuit includes a plurality of voltage follower circuits, each of which is disposed on a circuit board to which each electrode of the She Dianji and She Dianji sets is connected, and is configured to follow a potential difference between the electrode and the scalp, and output a voltage signal identical to the potential difference, so that the active electrode is in a normal working state.

In the above embodiment, the voltage follower circuit is provided in the brain signal acquisition circuit to solve the problem of high inherent impedance between the scalp and the electrode. When higher inherent impedance exists between the electrode and the scalp, the electrode is in a Lead off state, namely brain signals cannot be normally acquired. In order to reduce such impedance, the present invention uses a voltage follower circuit (voltage follower) that can accurately copy the voltage of an input signal to an output terminal without introducing additional impedance or distortion. By connecting the voltage follower circuit to the dry electrode, the inherent impedance between the dry electrode and the scalp can be effectively reduced.

the voltage follower circuit can follow the potential difference between the electrode and the scalp and output the same voltage signal, so that the electrode is kept in a normal working state. Thus, the accuracy and stability of brain signal acquisition can be effectively improved.

Those of ordinary skill in the art will appreciate that the various illustrative components, systems, and methods described in connection with the embodiments disclosed herein can be implemented as hardware, software, or a combination of both. The particular implementation is hardware or software dependent on the specific application of the solution and the design constraints. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, a plug-in, a function card, or the like. When implemented in software, the elements of the invention are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine readable medium or transmitted over transmission media or communication links by a data signal carried in a carrier wave. A "machine-readable medium" may include any medium that can store or transfer information. Examples of machine-readable media include electronic circuitry, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio Frequency (RF) links, and the like. The code segments may be downloaded via computer networks such as the internet, intranets, etc.

It should also be noted that the exemplary embodiments mentioned in this disclosure describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above-described steps, that is, the steps may be performed in the order mentioned in the embodiments, or may be performed in a different order from the order in the embodiments, or several steps may be performed simultaneously.

the software may be disposed in Random Access Memory (RAM), memory, read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

In this disclosure, features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and various modifications and variations can be made to the embodiments of the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-form dry electrode brain signal acquisition device, which is characterized by comprising a body, and a forehead She Dianji group (4-1) and a non-forehead She Dianji group which are arranged on the body;

The forehead She Dianji group (4-1) comprises a plurality of sheet-shaped dry electrodes (41) which are arranged on the frontal lobe area of the body corresponding to the user, and the non-frontal lobe electrode group comprises a plurality of needle-shaped dry electrodes (42) which are arranged on the non-frontal lobe area of the body corresponding to the user; wherein the frontal brain region comprises at least one of: a frontal lobe brain region, a posterior lobe brain region, the non-frontal lobe brain region comprising at least one of: parietal brain region, occipital brain region, temporal brain region.

2. The dual-modality dry electrode brain signal acquisition device of claim 1, wherein,

The body is of an integrated hard structure; or,

The body is of an integrated elastic cap type structure.

3. The brain signal acquisition device of a dual-form dry electrode according to claim 1 or 2, wherein the sheet-like dry electrode (41) is a passive dry electrode, the sheet-like dry electrode (41) has a wafer structure with a preset thickness, and a substrate is red copper, a plating layer is silver, or the substrate is red copper, and the plating layer is silver plating silver chloride.

4. The dual-modality dry electrode brain signal acquisition device according to claim 1 or 2, wherein the needle-shaped dry electrode (42) is a passive dry electrode, the needle-shaped dry electrode (42) is a single-acquisition-point spring needle assembly (42A), which comprises a thimble (42A-1), a sleeve (42A-2) and a spring (42A-3) arranged in the sleeve (42A-2), the thimble (42A-1) is arranged in the sleeve (42A-2) through the spring (42A-3), the thimble (42A-1) has a working stroke capable of extending and retracting along the axis of the sleeve (42A-2), and a substrate of the needle-shaped dry electrode (42) is red copper and a plating layer is silver.

5. the dual-modality dry electrode brain signal acquisition device according to claim 1 or 2, wherein,

the needle-shaped dry electrode (42) is a passive dry electrode, the needle-shaped dry electrode (42) is a claw-shaped electrode (42B) with a plurality of collecting points, the needle-shaped dry electrode comprises a base (42B-1) and a plurality of electrode needles (42B-2) arranged on the base (42B-1), and the electrode needles (42B-2) are uniformly distributed on one side of the base (42B-1).

6. The dual-modality dry electrode brain signal acquisition device according to claim 1 or 2, wherein the sheet-like dry electrode (41) and/or the needle-like dry electrode (42) is an active dry electrode, the sheet-like dry electrode (41) and/or the needle-like dry electrode (42) being provided on a circuit board (43) comprising a voltage follower circuit.

7. The apparatus for collecting brain signals with dual-modality dry electrode of claim 6, wherein,

In the case that the needle-shaped dry electrode (42) is an active dry electrode, the needle-shaped dry electrode (42) is a claw-shaped electrode (42B) with a plurality of collecting points, the electrode comprises a base (42B-1) and a plurality of electrode pins (422) arranged on the base (42B-1), the electrode pins (42B-2) are uniformly distributed on one side of the base (42B-1), and the base (42B-1) is welded on the circuit board (43).

8. The brain signal acquisition device of the dual-form dry electrode according to claim 4, wherein the needle-shaped dry electrode (42) is a spring needle assembly (42A) with a single acquisition point, a maximum contact resistance of 50mΩ at a working height, an elastic force of 10 g-30 g at a normal working height, a working stroke of 3.5mm±0.02, and a working height of 6.5mm±0.02.

9. The dual-modality dry electrode brain signal acquisition device according to claim 1, wherein one of the sheet-like dry electrodes (41) of the plurality of sheet-like dry electrodes (41) included in the forehead She Dianji group (41) is a GND electrode.

10. the dual-form dry electrode brain signal acquisition device according to claim 2, wherein the body of the integrated hard structure comprises a first half ring (1) corresponding to a frontal lobe brain region, a second half ring (2) corresponding to a occipital lobe brain region and a third half ring (3) corresponding to a parietal lobe brain region and/or a temporal lobe brain region, the three half rings of the body are mutually connected into an integrated structure, the frontal She Dianji group (4-1) is arranged on the inner side surface of the first half ring (1), and the inner side surface of the second half ring and/or the third half ring is provided with the non-frontal She Dianji group; and at least two of the first semi-ring, the second semi-ring and the third semi-ring are arranged to be of a telescopic structure.

11. A brain signal acquisition method, characterized in that the method employs a dual-modality dry electrode brain signal acquisition device according to any one of claims 1 to 10, the method comprising:

12. The brain signal acquisition method according to claim 11, further comprising:

Filtering high-frequency noise of the brain signal by using a low-pass filter;

13. The brain signal acquisition method according to claim 12, wherein the sheet-like dry electrode and/or the needle-like dry electrode is an active dry electrode, the method further comprising:

14. A brain signal acquisition circuit for implementing the brain signal acquisition method according to any one of claims 11-13, the acquisition circuit comprising:

15. The brain signal acquisition circuit according to claim 14, wherein the sheet-like dry electrode and/or the needle-like dry electrode is an active dry electrode, the acquisition circuit further comprising: the voltage follower circuits are arranged on the circuit board connected with the electrodes of the She Dianji group and the She Dianji group and used for following the potential difference between the electrodes and the scalp and outputting a voltage signal identical to the potential difference so that the active electrode is in a normal working state.