CN109893131B - Electrode and system for bioelectric signal sensing - Google Patents

Abstract

The present invention discloses an electrode and a system for bioelectric signal sensing. The present invention increases the storage capacity of the electrolyte by arranging an absorption component to absorb electrolyte, and the signal stability of the wet electrode is better. In addition, the electrode probe is provided with a covering portion covered with an insulating protective layer, which effectively avoids the defect of shortening the use time of the electrode due to long-term exposure of the electrode probe, overcomes the technical problems in the prior art that the dry electrode signal stability is poor and the wet electrode has a short use time, and realizes a long electrode use time and good signal stability.

Description

Electrode and system for bioelectric signal sensing

Technical Field

The present invention relates to the field of bioelectric signals, and in particular to an electrode and a system for sensing bioelectric signals.

Background Art

Bioelectric signals include electrocardiogram (ECG), electroencephalogram (EEG) or electromyography (EMG). EEG is the sum of cortical potentials of the brain for physiological and psychological activities. The collection and acquisition of EEG plays an important role in brain disease diagnosis, brain-computer interface, psychological intervention, sleep monitoring, etc.; it is also the core technology of cognitive neuroscience and is widely used in scientific research in modern psychology, medicine and other fields.

So far, EEG electrodes can be divided into lossy and non-destructive electrodes. Although lossy electrodes can directly contact the cortex, they must puncture the skin or open the skull, which is very risky. Non-destructive electrodes are divided into dry electrodes and wet electrodes. As the name suggests, dry electrodes are dry where the electrode contacts the skin (it is not absolutely "dry", there are still trace amounts of electrolytes between the electrode and the skin, such as moisture from the surrounding environment or sweat on the skin). This type of electrode is easy to operate and does not require special cleaning of the scalp, but has a low signal-to-noise ratio and poor stability, and has been rarely used for scientific research purposes so far.

A wet electrode is a conductive medium filled in the gap between the skin and the electrode, so that a metal-electrolyte interface is formed between the electrode and the human skin surface. Wet electrodes are divided into two categories. One is a conductive paste electrode, which has ultra-high skin impedance and high signal-to-noise ratio signals, and has the advantages of excellent conductivity, stable signals, and high signal-to-noise ratio. However, its main disadvantage is that it is time-consuming and labor-intensive. For example, it takes time to clean the skin; each electrode must be injected with an appropriate amount of conductive paste to achieve good contact between the scalp and the electrode; and the hair must be washed after the test. The conductive paste wet electrode is processed by filling the scalp-hair gap with conductive paste until it contacts the electrode. However, the amount and timing of the conductive paste injection are highly dependent on the personal experience and skills of the operator. If there is too much conductive paste, the electrodes will stick together and different electrodes will be easily connected in series. If there is too little conductive paste, the contact will be poor. Wet electrodes have been widely used in scientific research, but the above unfavorable factors have greatly limited the practical application of wet electrodes in brain-computer interfaces, psychological assessment and intervention, and are not suitable for scientific research on some special groups, such as the elderly, children, and patients. Another type of wet electrode is the saline electrode, which can avoid the time-consuming and laborious disadvantages of the conductive paste electrode. It does not need to be time-consuming and laborious to inject conductive paste into each electrode, and there is no need to wash the hair after the test. It has been widely used in scientific research and practical applications. However, its disadvantage is that the saline is easy to dry, and the test cannot be continued for too long. It is often necessary to add saline to each hole every half an hour or so. This greatly limits the promotion and use of EEG technology in scientific research and application fields. For example, we cannot inject electrolyte every half an hour for drivers while driving.

Summary of the invention

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one object of the present invention is to provide an electrode for bioelectric signal sensing, which is used to extend the sensing time of the electrode.

To this end, a second object of the present invention is to provide a system for bioelectric signal sensing.

The technical solution adopted by the present invention is:

In a first aspect, the present invention provides an electrode for sensing bioelectric signals, comprising an absorption component for absorbing electrolyte and a plurality of electrode probes, wherein the electrode probes include a contact portion in contact with the absorption component, a covering portion covered with an insulating protective layer, and a signal collection portion in contact with the skin of a subject, the contact portion of the electrode probe absorbs electrolyte from the absorption component and transports it to the signal collection portion through the covering portion for discharge.

Furthermore, the electrode further comprises a first mounting plate, the electrode probe is mounted on the first mounting plate, and the covering part and the signal collecting part of the electrode probe extend out from the first mounting plate.

Furthermore, the electrode also includes a second mounting plate and a shell, one end of the electrode probe where the contact portion is located is connected to the second mounting plate, the shell is respectively connected to the second mounting plate and the first mounting plate to form a closed cavity, and the absorption component is arranged inside the closed cavity.

Furthermore, the first mounting plate is detachably connected to the housing.

Furthermore, the edge of the first mounting plate is wholly or partially serrated, the shell has a groove, a serrated portion is correspondingly arranged in the groove, and the serrated portion cooperates with the serrated edge of the first mounting plate to achieve a detachable connection between the first mounting plate and the shell.

Furthermore, the second mounting plate is provided with a liquid filling hole for injecting electrolyte.

Furthermore, the first mounting plate is covered with an anti-corrosion coating.

Furthermore, the first mounting plate further comprises an electrode lead lead-out portion, the absorbing component is in contact with the anti-corrosion coating, an electrode lead is arranged on the electrode lead lead-out portion, and the electrode lead is connected to the anti-corrosion coating.

Furthermore, the absorbent component includes a sponge.

In a second aspect, the present invention provides a system for bioelectric signal sensing, comprising the electrodes for bioelectric signal sensing.

The beneficial effects of the present invention are:

The present invention increases the storage capacity of the electrolyte by arranging an absorption component to absorb the electrolyte, and the signal stability of the wet electrode is better. In addition, the electrode probe is provided with a covering portion covered with an insulating protective layer, which effectively avoids the defect of shortening the use time of the electrode due to long-term exposure of the electrode probe, overcomes the technical problems of poor signal stability of the dry electrode and short use time of the wet electrode in the prior art, and realizes long electrode use time and good signal stability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a specific embodiment of an electrode probe for bioelectric signal sensing in the present invention;

FIG2 is a schematic structural diagram of a specific embodiment of an electrode for bioelectric signal sensing in the present invention;

FIG. 3 is a schematic structural diagram of a specific embodiment of a first mounting plate of an electrode for bioelectric signal sensing in the present invention.

DETAILED DESCRIPTION

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

Example 1

An electrode for bioelectric signal sensing includes an absorption component for absorbing electrolyte and a plurality of electrode probes. The electrode probe includes a contact portion in contact with the absorption component, a covering portion covered with an insulating protective layer, and a signal collection portion in contact with the skin of a subject. The contact portion, the covering portion, and the signal collection portion are arranged in sequence. The contact portion of the electrode probe absorbs electrolyte from the absorption component and transports it to the signal collection portion through the covering portion for discharge. Wherein, referring to FIG1 , FIG1 is a schematic structural diagram of a specific embodiment of an electrode probe of an electrode for bioelectric signal sensing in the present invention; in this embodiment, the electrode probe 1 is a pen tip type electrode probe, and the material of the electrode probe 1 includes a hydrophilic resin. Specifically, the electrode probe 1 is made of a hydrophilic polyester fiber mixed resin (the pen tip of a commonly used water-based pen is made of this material), which can easily absorb an electrolyte solution, such as salt water. The total length of the electrode probe 1 is about 15 mm, of which the head 9 of the electrode probe 1 has a diameter of about 2.5 mm and a length of 1.2 mm, and is cylindrical; the remaining portion is conical, and the diameter of the cone tail 10 of the electrode probe 1 (i.e., the portion in contact with the subject's skin, i.e., the signal collection portion) is about 1-2 mm, slightly elastic, will not pierce the skin, will not feel pain, and is non-invasive to the human body. The pen-tip electrode probe can easily pass through the hair. In addition, the absorption component is realized by a strong water-absorbing sponge, which plays the role of storing electrolyte (such as saline) and increases the storage capacity of electrolyte. The contact part of the electrode probe and the water-absorbing sponge can quickly guide the electrolyte therein to the cone tail (i.e., the signal acquisition part) of the electrode probe, and release the electrolyte to the skin through the cone tail. The electrode probe is provided with a covering part covered with an insulating protective layer. Compared with the saline electrode with a very short use time, this structure can extend the use time by several times; effectively avoid the defect of shortening the use time of the electrode due to long-term exposure of the electrode probe, and the signal stability of the wet electrode is better; overcome the technical problems of poor signal stability of dry electrodes and short use time of wet electrodes in the prior art, and achieve long use time of electrodes and good signal stability. The electrode in this embodiment can be widely used in the collection of electrocardiogram, electroencephalogram, electromyography and other signals, especially for the collection of electroencephalogram signals, and has a good collection effect.

Specifically, referring to Figures 1, 2 and 3, Figure 2 is a schematic structural diagram of a specific embodiment of an electrode for bioelectric signal sensing in the present invention, and Figure 3 is a schematic structural diagram of a specific embodiment of a first mounting plate of an electrode for bioelectric signal sensing in the present invention; the electrode also includes a first mounting plate 6, a second mounting plate 4 and a shell 5, the shell 5 is respectively connected to the second mounting plate 4 and the first mounting plate 6 to form a closed cavity, and the absorption component is arranged inside the closed cavity. The absorption component takes a water-absorbing sponge 8 as an example, wherein the shell 5 is a cylindrical shell, the first mounting plate 6 and the second mounting plate 4 are both circular, and the first mounting plate 6 is a cylindrical shell. The second mounting plate 4 is connected to the upper part of the outer shell 5. The second mounting plate 4 and the outer shell 5 can be integrally formed, or the second mounting plate 4 and the outer shell 5 can be detachably connected by screws; and the first mounting plate 6 is detachably connected to the outer shell 5. In this embodiment, the edge of the first mounting plate 6 is all or partially serrated, and the lower part of the outer shell 5 has a groove (not shown), and a serrated portion (not shown) is correspondingly arranged in the groove. The serrated portion cooperates with the serrated edge of the first mounting plate 6 to enable the first mounting plate 6 and the outer shell 5 to be detachably connected. The serrated connection makes the installation and removal of the first mounting plate 6 very convenient and quick. One end of the electrode probe 1 where the contact portion is located is fixedly connected to the mounting hole 11 on the second mounting plate 4. In FIG. 2 , the number of electrode probes 1 is taken as 5, and 5 mounting holes are provided on the second mounting plate 4; the electrode probe 1 is mounted and fixed on the first mounting plate 6 through the fixing hole 12 on the first mounting plate 6, and accordingly, the first mounting plate 6 has 5 fixing holes 12; and the covering portion and the signal acquisition portion of the electrode probe 1 extend from the first mounting plate 6, that is, the contact portion of the electrode probe 1 is located inside the cavity, and the covering portion and the signal acquisition portion of the electrode probe 1 extend from the first mounting plate 6, and the length of the extended portion is about 3-5 mm. The extended portion is coated with an insulating protective film (i.e., an insulating protective layer) except for the cross section of the tapered tail 10 of the electrode probe, which can protect the electrode probe, avoid contact with hair and introduce detection noise, and reduce the contact area between the electrolyte such as salt water and the air to prevent the electrolyte from evaporating quickly. In this embodiment, the water-absorbing sponge 8 is a strong water-absorbing sponge formed by cylindrical stamping. Accordingly, the water-absorbing sponge 8 is provided with 5 through holes for the electrode probe 1 to pass through and realize contact with the water-absorbing sponge 8. In addition, the first mounting plate 6 is covered with an anti-corrosion coating, which can be plated with Ag-AgCl (or nickel, titanium, gold, tin and other salt water corrosion-resistant metals); the first mounting plate 6 also includes an electrode lead lead-out portion 7, and the absorbing component such as the water-absorbing sponge 8 contacts the anti-corrosion coating to realize the transmission of the detection signal (such as the electroencephalogram signal), and the electrode lead lead-out portion 7 is provided with an electrode lead, and the electrode lead is connected to the anti-corrosion coating. That is, the anti-corrosion coating is provided to facilitate the transmission of the electroencephalogram signal collected from the electrode probe 1 to the electrode lead, thereby improving the quality of the detection signal. The motor lead lead-out portion 7 just extends out through a notch at the bottom of the housing 5. In addition to having the function of leading out the detection signal, it can also play a role in fixing the first mounting plate 6 and the second mounting plate 4 so that they cannot rotate at will.

The electrodes of this embodiment use 5 (or less, or more) pen-tip electrode probes installed on the same plane (i.e., the first mounting plate and the second mounting plate), which can penetrate the hair without damaging the scalp and can make good contact with the scalp, thereby obtaining weak EEG signals on the scalp surface; and after removing the electrodes, only 5 (or less, or more) small water spots are left on the scalp, which will dry naturally very quickly, and there is no need to clean the hair afterwards, making it more widely used; by providing an absorption component, the electrode not only has the advantages of high signal-to-noise ratio and stable signal of traditional wet electrodes, but also avoids the disadvantages of traditional wet electrodes such as short maintenance time and the need to wash hair afterwards, and is easy to operate and can record for a long time.

Referring to Figure 2, the second mounting plate 4 is provided with a filling hole 4 for injecting electrolyte. In the present embodiment, two filling holes 4 are provided. By utilizing the filling holes 4, electrolyte can be added in the middle of signal sensing to achieve the purpose of long-term use. In addition, the electrode is also provided with a mounting portion, which is used to fix the electrode on other equipment. In the present embodiment, a skirt 2 is provided at the lower part of the outer shell 5, and a through hole 13 is provided on the skirt 2. The electrode can be conveniently installed on the electrode cap or the electrode belt through the through hole 13 to achieve electrode fixation.

Example 2

Embodiment 2 is provided based on embodiment 1. Embodiment 2 provides a system for bioelectric signal sensing, including the electrode for bioelectric signal sensing described in embodiment 1.

The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims (4)

1. An electrode for bioelectric signal sensing, characterized by comprising an absorbing member for absorbing an electrolyte and a plurality of electrode probes, the electrode probes comprising a contact portion in contact with the absorbing member, a cover portion covered with an insulating protective layer, and a signal acquisition portion in contact with the skin of a subject, the contact portion of the electrode probes sucking the electrolyte from the absorbing member and delivering it to the signal acquisition portion through the cover portion for discharge, the electrode probes being made of a hydrophilic polyester fiber mixed resin;

The electrode probe is arranged on the first mounting plate, and the covering part and the signal acquisition part of the electrode probe extend out of the first mounting plate; the end of the contact part of the electrode probe is connected with the second mounting plate, the shell is respectively connected with the second mounting plate and the first mounting plate to form a closed cavity, the absorption part is arranged in the closed cavity, and the first mounting plate is detachably connected with the shell; the second mounting plate and the shell are integrally formed or detachably connected; the absorption part is provided with a through hole for the electrode probe to pass through so as to realize the contact between the electrode probe and the absorption part;

The edge of the first mounting plate is wholly or partially serrated, the shell is provided with a groove, a serrated part is correspondingly arranged in the groove, and the serrated part is matched with the serrated edge of the first mounting plate so as to realize detachable connection between the first mounting plate and the shell;

The anti-corrosion coating is covered on the first mounting plate, the first mounting plate further comprises an electrode lead guiding-out part, the absorption part is in contact with the anti-corrosion coating to realize detection signal transmission, an electrode lead is arranged on the electrode lead guiding-out part, the electrode lead is connected with the anti-corrosion coating, and the electrode lead guiding-out part extends out through a notch at the lower part of the shell.

2. The electrode for bioelectric signal sensing according to claim 1, wherein a liquid charging hole for charging an electrolyte is provided on the second mounting plate.

3. The electrode for bioelectric signal sensing of claim 1, wherein the absorbent member comprises a sponge.

4. A system for bioelectric signal sensing, characterized by comprising an electrode for bioelectric signal sensing according to any of claims 1 to 3.