A flexible electrode with real-time adjustable detection position

Abstract

This case involves a flexible electrode with real-time adjustable detection position, which is used to solve the problem that the detection position of existing fixed-structure electrodes cannot be adjusted after attachment to quickly and accurately locate the location of the disease or target nerves and muscles, as well as the problems of wasted time, material waste, electrode performance degradation, skin discomfort or damage caused by changing the detection position and the need to replace or re-attach the electrodes. The electrode in this case is composed of a flexible substrate with a hole structure, an electromagnetic fluid, and a flexible packaging layer. After the electrode is attached to the skin, by pressing the area of ​​the packaging layer corresponding to the electromagnetic fluid, the electromagnetic fluid passes through the holes in the flexible substrate under pressure and contacts the skin for signal acquisition. The electromagnetic fluid can be sucked back from the holes through the holes into the cavity space between the substrate and the packaging layer by a magnet; when the detection position needs to be changed, the electromagnetic fluid is moved between the substrate and the packaging layer by a magnet, so that the electrode can be attached once and the detection position can be adjusted at any time.

Description

Technical Field

[0001] This case involves electrophysiological detection and monitoring technology, and in particular, a flexible electrode with real-time adjustable detection position. Background Art

[0002] Electrophysiological signal monitoring plays a vital role in modern medical and technological applications, and is widely used in a variety of fields, including disease diagnosis, treatment effect evaluation, rehabilitation process tracking, human-computer interaction, and health management and prevention. In the medical and health field, high-quality electrophysiological signal monitoring can improve the timeliness and accuracy of disease diagnosis, helping doctors quickly identify the cause of the disease, thereby formulating appropriate treatment plans and improving the effectiveness of rehabilitation treatment. In the field of human-computer interaction, the precise acquisition of electrophysiological signals from targeted nerves or muscles can improve the accuracy of intent recognition, enhance the interactive experience, and thus enhance the reliability of human-computer interaction applications. As the core tool for collecting neural electrophysiological signals, electrodes' signal acquisition capabilities and user experience are crucial for practical back-end applications based on electrophysiological signals.

[0003] Although conventional electrodes can already collect high-quality electrophysiological signals, existing electrode technology has significant limitations in achieving accurate signal acquisition and user experience. Because human physiological signals are often formed by the superposition of multiple muscles or neurons and are highly complex, and the state and size of human tissue vary from person to person, it is quite difficult to accurately attach electrodes to an individual and accurately collect electrophysiological signals in a single operation. Furthermore, during the detection of neuromuscular diseases, the electrode position often needs to be adjusted multiple times to accurately locate the symptom. Traditional electrodes are generally fixed in structure, and once attached to the skin or tissue surface, they are difficult to flexibly adjust, making it difficult to obtain the optimal signal monitoring site or high-quality signals in a single operation. To this end, it is often necessary to remove and reattach the electrodes or simply replace them, which not only increases the complexity of the operation but also significantly increases material and time costs. Furthermore, frequent removal and reattachment operations can cause skin discomfort or damage, such as pain, redness, swelling, and allergic reactions, which not only affects the wearing experience of the electrodes but also reduces the reliability and stability of signal acquisition. Therefore, developing reliable electrodes to achieve rapid and accurate acquisition of electrophysiological signals at different locations while avoiding repeated sticking and frequent replacement of electrodes is of great significance for improving the wearing experience of electrodes, achieving accurate disease diagnosis and treatment, and high-quality human-computer interaction.

[0004] To accurately collect electrophysiological signals from targeted nerves or muscle tissue within a single area without the need for repeated electrode attachment or replacement, multi-channel electrode arrays and removable electrodes have been developed. Multi-channel electrode arrays contain multiple independent detection channels within a specific area. After a single attachment, electrophysiological signals can be collected simultaneously from multiple locations without repositioning, enabling rapid localization of lesions or targeted nerves. However, the large number of channels in these electrodes significantly increases the structural complexity and cost of both the electrodes and the acquisition equipment. Summary of the Invention

[0005] To address some or all of the above issues, this proposal proposes a novel flexible electrode structure with real-time adjustable detection position. By designing and fabricating a removable conductive magnetic fluid detection layer, not only can the electrode detection position be arbitrarily changed without changing the overall electrode position, but it also ensures stable adhesion between the electrode substrate and the skin, ensuring high-quality signal detection while avoiding the discomfort and damage caused by disengagement of the electrode from the skin during repositioning.

[0006] In a first aspect, the present disclosure proposes a flexible electrode with real-time adjustable detection position, wherein the flexible electrode includes an electromagnetic conductive fluid, a substrate, and an encapsulation layer, wherein the substrate and the encapsulation layer are combined to form a cavity, confining the electromagnetic conductive fluid within the cavity; the electromagnetic conductive fluid is a semi-solid conductive material that can deform and move under the action of an external force or a magnetic field; the substrate has holes, and the surface of the encapsulation layer corresponding to the electromagnetic conductive fluid is pressed to squeeze the electromagnetic conductive fluid, and the electromagnetic conductive fluid partially contacts the skin through a number of holes to collect electrophysiological signals of the skin, and the electromagnetic conductive fluid that passes through the holes can return to the cavity space under the action of the magnetic field; the substrate is a flexible and stretchable polymer film, and its adhesion to the skin is not only greater than the gravity of the electrode itself, but also greater than the adhesion between the electromagnetic conductive fluid and the skin, thereby ensuring that the flexible electrode can stably collect signals under different skin conditions.

[0007] In one implementation of the above technical solution, a wire is used to connect the conductive electromagnetic fluid to an external device.

[0008] In one embodiment of the above technical solution, the components of the conductive magnetic fluid include solvent, polymer, magnetic particles, conductive material, and additives, and the mass proportions of each component are 35% to 65%, 2% to 18%, 15% to 40%, 0% to 25%, and 0.1% to 10%, respectively; the solvent is water or ethanol; the polymer is polyethylene glycol, dextran, polyvinyl pyrrolidone or liquid silica gel; the magnetic particles are ferric oxide, ferroferric oxide, nickel or rubidium iron boron powder, the conductive material is metal particles, carbon material or conductive polymer, and the additive is a polymer cross-linking agent, glycerol, polyethylene glycol, sodium chloride or potassium chloride.

[0009] In one embodiment of the above technical solution, the material of the flexible and stretchable polymer film is one or more of the following composites: polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), isoprene-substituted butadiene block styrene polymer (SIS), and polyparaxylene.

[0010] In one embodiment of the above technical solution, the thickness of the flexible and stretchable polymer film is 100 nm-10 mm.

[0011] In one implementation of the above technical solution, the magnetic field is provided by a magnet.

[0012] In one embodiment of the above technical solution, the holes are regular or irregular in shape or a combination of regular and irregular shapes, and the area is The distance between the edge of the hole and the adjacent hole is 0.1 μm-10 mm.

[0013] In one embodiment of the above technical solution, there are multiple electromagnetically conductive fluids.

[0014] In a second aspect, the present disclosure proposes a flexible electrode, which includes a cavity, the bottom of which adheres to the skin through its own physical action or adhesive; there is an electromagnetic fluid in the cavity, and pressing the cavity surface corresponding to the position of the electromagnetic fluid can enable the electromagnetic fluid to contact the skin through the holes at the bottom of the cavity, thereby collecting the electrophysiological signals of the skin.

[0015] In one embodiment of the above technical solution, the bottom of the cavity is made of a flexible and stretchable polymer film, and its adhesion to the skin is not only greater than the weight of the electrode itself, but also greater than the adhesion between the conductive electromagnetic fluid and the skin.

[0016] Beneficial technical effects: The electrodes designed and prepared by the present invention only need to be attached once, that is, the detection position can be adjusted at any time, avoiding material waste and time consumption when replacing electrodes and adjusting detection positions, and can reduce possible skin discomfort, damage, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 、 one Schematic diagram of a flexible electrode with real-time adjustable detection position in an embodiment.

[0019] Figure 2 、 one Schematic diagram of the magnetic fluid in the flexible electrode with real-time adjustable detection position moving by magnet attraction in this embodiment.

[0020] Figure 3 、 one Schematic diagram of the embodiment before being pressed.

[0021] Figure 4 、 one Schematic diagram after being pressed in the first embodiment.

[0022] Figure 5 、 one Schematic diagram of the electromyographic (EMG) signal measured before the magnetic fluid moves in this embodiment.

[0023] Figure 6 、 one Schematic diagram of the EMG signal measured after the magnetic fluid moves in this embodiment.

[0024] In the figure: ① packaging layer, ② conductive magnetic fluid, ③ substrate, ④ wire, ⑤ magnet, ⑥ skin. DETAILED DESCRIPTION

[0025] Based on the background technology, it can be seen that the existing technology has the following problems: the existing fixed structure electrodes cannot change the detection position after attachment, making it difficult to quickly and accurately monitor the signals of the targeted nerves or muscles or locate the location of the disease; although the existing multi-channel electrodes can simultaneously perform electrophysiological signal testing on multiple locations in a large area to achieve precise positioning, the multi-channel electrodes are relatively expensive and have high requirements on the complexity and performance of the acquisition equipment; the existing movable surface electrodes have insufficient adhesion and stability on the body surface, making it difficult to achieve reliable use under different skin conditions and positions.

[0026] This case proposes a flexible electrode structure design that can change its position in real time. Under the premise that the overall electrode position does not change after a single attachment, the electrode detection position can be arbitrarily changed by adjusting the position of the conductive electromagnetic fluid to achieve electrophysiological signal detection at any position in a large area, thereby overcoming the problem that the traditional fixed electrode structure cannot be adjusted after attachment, as well as a series of problems such as time waste, material waste, skin discomfort or damage caused by replacing or re-attaching electrodes due to the need to change the detection position.

[0027] The following, combined with the accompanying drawings, provides a clear and complete description of how the technical solution of this case is implemented. Obviously, the described implementation methods are only part of the implementation methods of this case, not all of the implementation methods. Based on the implementation methods of this case, all other implementation methods obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0028] (1) Structural design of electrodes

[0029] The electrode includes a substrate, an electromagnetically conductive fluid, and an encapsulation layer. The substrate, the electromagnetically conductive fluid, and the encapsulation layer form a "sandwich" structure, wherein the substrate and the encapsulation layer combine to form a cavity, confining the electromagnetically conductive fluid within the cavity. The substrate is located at the bottom of the electrode and directly contacts the skin. The encapsulation layer is located on top of the electrode, and its edges can be assembled with the flexible substrate, either by gluing or other detachable methods. A cavity is formed between the encapsulation layer and the substrate. Within this cavity, the electromagnetically conductive fluid, which serves as the sensing portion of the electrode, is confined.

[0030] The conductive electromagnetic fluid can move freely, without leaking or coming into contact with the external environment. The substrate has holes. Before the electrode is used, the conductive electromagnetic fluid, due to its high viscosity, remains on the flexible substrate and does not leak through the holes or come into contact with the skin. The substrate effectively separates the conductive electromagnetic fluid from the skin. After the electrode is attached to the skin, the encapsulation layer above the conductive electromagnetic fluid is pressed, forcing the conductive electromagnetic fluid to pass through the holes in the substrate and come into contact with the skin, enabling the collection of physiological electrical signals.

[0031] After signal acquisition is completed, a magnet or a magnetic field generated in real time can be used to absorb the electromagnetic fluid from the holes on the substrate back into the cavity space between the substrate and the packaging layer.

[0032] When changing the detection position, a magnet or a magnetic field generated in real time can be used to change the position of the electromagnetic fluid between the substrate and the packaging layer, and then the electromagnetic fluid is pressed through the holes in the substrate to contact the skin for signal detection. This allows the electrode to be attached once and the position to be adjusted at any time to detect electrophysiological signals within a certain area, avoiding the problems of conventional electrode collection points being fixed and immovable, the high cost of multi-channel electrodes, the complex collection equipment, and the poor stability of existing movable electrodes on the body surface.

[0033] See also Figure 1 The electrode shown is composed of a substrate ③, a conductive electromagnetic fluid ②, and an encapsulation layer ①. The substrate has regularly arranged circular holes, but the hole size, shape, and arrangement can be further designed. The conductive electromagnetic fluid is connected to an external device via a wire ④. Figure 2 , the position of the electromagnetic fluid can be changed by using magnets, Figure 2(a) shows the position of the conductive fluid before it is changed by magnets. Figure 2 (b) in the figure shows the position of the right magnetic fluid in the two magnetic fluids after it is moved to the right by a magnet. Figure 3 and Figure 4 , respectively, are the states of the conductive electromagnetic fluid before and after pressing. Before pressing, the conductive electromagnetic fluid is located between the substrate and the packaging layer. After pressing, the conductive electromagnetic fluid is squeezed into the holes and contacts the skin ⑥.

[0034] It can be seen from this that when the electrode substrate in this case is adhered to the skin, the electrode detection position can be changed without changing the overall position of the electrode, thereby avoiding the material and time costs of replacing the electrode and detection position, and also reducing skin discomfort, damage, etc.

[0035] When the entire cavity formed by the substrate and the packaging layer is filled with an electromagnetically conductive fluid, signal acquisition can be achieved across the entire skin area covered by the electrode. If a magnet or magnetic field is placed on the packaging layer, the electromagnetically conductive fluid can be controlled to maintain contact with the skin. Figure 2 The magnets used are ⑤.

[0036] (2) Material selection

[0037] The substrate is preferably made of a flexible and stretchable film material, so that the substrate can form a certain adhesion with the skin through physical or chemical effects, and can be processed into a film structure with holes.

[0038] The encapsulation layer is preferably made of a flexible and stretchable film material so that the prepared electrode can be soft, deformable and stretchable as a whole.

[0039] The conductive magnetic fluid material requires high magnetic deformation capacity, a certain level of conductivity, viscosity, and conformality. It also needs to have low adhesion to the skin and no adhesion to the substrate or packaging layer. When static, it will not diffuse through the pores of the flexible substrate, but when pressed, it can pass through the pores of the substrate and contact the skin. The low interfacial impedance when in contact with the skin ensures high-quality signals while avoiding the discomfort and damage caused by the conductive magnetic fluid debonding when changing positions.

[0040] The electrode assembled in this way is a flexible electrode that can fit closely to the skin without causing discomfort.

[0041] (3) Electrode preparation method

[0042] (3.1) Substrate

[0043] The substrate is preferably a flexible and stretchable polymer film that can form strong adhesion with the skin through its own physical action or adhesive.

[0044] Prepare a polymer film with a microporous structure. The film thickness is preferably between 100 nm and 10 mm (including any value within the boundaries), and the size and shape are not limited. The material used is preferably a flexible material with good biocompatibility, including but not limited to polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), isoprene-substituted butadiene block styrene polymer (SIS), polyparaxylene, etc. These materials ensure that the adhesion force between the prepared substrate and the skin is greater than the weight of the electrode itself and greater than the adhesion force between the conductive magnetic fluid and the skin, thereby ensuring that the flexible electrode can stably collect signals under different skin conditions.

[0045] The preparation methods of the film include but are not limited to printing, doctor blade coating, casting, spin coating, hot pressing, etc. The micropores on the film can be regular shapes such as round, square, triangle, or irregular shapes, or a combination of regular and irregular shapes. The hole sizes can be consistent or inconsistent, and the area size is controlled within The distance between the edge of the hole and the adjacent hole is 0.1µm-10 mm.

[0046] The accuracy of the flexible electrode's signal acquisition can be determined by the hole shape and spacing through simulation.

[0047] Micropores can be prepared by template method, mechanical cutting, laser cutting and other methods.

[0048] One side of the substrate can be selectively coated with a layer of adhesive, and the adhesive can be biocompatible pressure-sensitive adhesive, silicone, etc.

[0049] (3.2) Conductive electromagnetic fluid

[0050] The electroconductive fluid is a semi-solid conductive material that can deform and move under external forces or magnetic fields, allowing it to collect and transmit electrophysiological signals. Its adhesion to the skin is weaker than that of the flexible, stretchable film, making it easier to detach from the skin.

[0051] The electromagnetically conductive fluid is prepared using components including solvents, polymers, magnetic particles, conductive materials, and additives, with the weight proportions of each component ranging from 35% to 65%, 2% to 18%, 15% to 40%, 0% to 25%, and 0.1% to 10%, respectively. The weight proportions of each component include boundary values, and the electromagnetically conductive fluid obtained based on such weight proportions can achieve a certain degree of adhesion to the skin and is easy to remove from the skin. The solvents used are water, ethanol, etc.; the polymers are polyethylene glycol, dextran, polyvinyl pyrrolidone, liquid silicone, etc.; the magnetic particles are ferric oxide, ferroferric oxide, nickel, rubidium iron boron powder, etc.; the conductive materials are metal particles, carbon materials, conductive polymers, etc.; and the additives are polymer crosslinkers, glycerol, polyethylene glycol, sodium chloride, potassium chloride, etc.

[0052] The electromagnetically conductive fluid prepared in this way has high magnetic deformation ability, certain viscosity and conformality, low skin adhesion and interface impedance, and does not adhere to the substrate and packaging layer. This ensures that the electrode can quickly change the detection position without damaging the skin and can obtain high-quality electrophysiological signals.

[0053] (3.3) Encapsulation layer

[0054] A polymer film having the same shape and size as the flexible substrate is prepared, wherein the film thickness is between 100 nm and 10 mm. The material used is a flexible material with good biocompatibility, including but not limited to polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), isoprene-substituted butadiene block styrene polymer (SIS), polyparaxylene, etc. One or more composites thereof; the film preparation method includes but is not limited to printing, doctor blade coating, printing, casting, spin coating, hot pressing, etc.

[0055] It should be noted that the material of the encapsulation layer may be different from that of the substrate layer.

[0056] (3.4) Electrodes

[0057] A conductive magnetic fluid is placed between a flexible substrate and an encapsulation layer. Wires are then attached to the edges of the substrate, connecting them to the conductive magnetic fluid and the collection device. Finally, the flexible substrate and the edge of the encapsulation layer are bonded together to create a flexible electrode that can be repositioned in real time. Prior to application, the conductive magnetic fluid, due to its viscosity and conformality, remains on the flexible substrate, preventing it from leaking through holes in the substrate or coming into contact with the skin.

[0058] During use, after attaching the electrode to the skin, press the packaging layer area on the upper layer of the conductive electromagnetic fluid. The conductive electromagnetic fluid is pressurized and contacts the skin through the holes in the flexible substrate, thereby collecting signals. After a single test, a magnet is used to suck the conductive electromagnetic fluid back into the cavity space between the flexible substrate and the packaging layer through the holes in the flexible substrate. When the detection position needs to be changed, a magnet is used to attract the conductive electromagnetic fluid to change its position between the flexible substrate and the packaging layer, and then the conductive electromagnetic fluid is pressed through the holes in the flexible substrate to contact the skin to achieve signal detection. Finally, after the test is completed, a magnet is used to suck the conductive electromagnetic fluid out of the holes in the flexible substrate to the space between the flexible substrate and the sealing layer.

[0059] (IV) Experimental verification

[0060] (4.1) Example 1

[0061] Preparation of flexible substrate: A 2 mm thick 5 × 5 cm film was prepared using silicone rubber Ecoflex by casting a template and curing it at room temperature. Evenly distributed circular through-holes with a diameter of 1 mm were then generated on the film by mechanical punching, with a spacing of 3 mm between the holes.

[0062] Preparation of magnetically conductive fluid: Magnetically conductive fluid was prepared using ferroferric oxide. The preparation method was as follows: (1) Weigh an appropriate amount of PVA powder and dissolve it in deionized water to obtain a PVA solution with a concentration of 15 wt%. (2) Weigh 4.58 g of ferroferric oxide (particle size 100 nm, purity 99%), 11.3 g of PVA solution, and 0.17 g of additive (PVA crosslinker borax) and mix them to obtain a solvent, polymer, magnetic particles, and additive ratio of 59.9%, 10.5%, 28.5%, and 1.1%, respectively. Then, stir at 2000 rpm at room temperature for 2 minutes to ensure that all components are evenly mixed and complete the natural crosslinking of PVA, finally obtaining a magnetically conductive fluid.

[0063] Preparation of the encapsulation layer: A 1 mm thick 5 × 5 cm film was prepared using Ecoflex silicone rubber by casting a template and curing it at room temperature.

[0064] Electrode assembly: Take an appropriate amount of conductive electromagnetic fluid and place it between the flexible substrate and the packaging layer. Then fix the wires at the edge of the substrate and connect them to the conductive electromagnetic fluid and the collection device respectively. Then, bond the flexible substrate to the edge of the packaging layer to obtain a flexible electrode that can change position in real time.

[0065] Usage of electrodes: Clean the skin on the arm and attach the electrodes. Gently press the packaging layer area on the upper layer of the conductive electromagnetic fluid with your hand. After the conductive electromagnetic fluid is pressurized and contacts the skin through the holes in the flexible substrate, signal acquisition is performed when the arm makes a fist. After a single test, use a magnet to suck the conductive electromagnetic fluid back into the cavity space between the flexible substrate and the packaging layer through the holes in the flexible substrate, change the position of the conductive electromagnetic fluid in the flexible substrate and the packaging layer, and then press the conductive electromagnetic fluid through the holes in the flexible substrate to contact the skin. Signal acquisition is performed when the arm makes a fist again. After the final test, use a magnet to suck the conductive electromagnetic fluid out to the middle of the flexible substrate and the sealing layer.

[0066] (4.2) Example 2

[0067] Preparation of flexible substrate: A 5 mm thick, 6 cm diameter circular film was prepared using silicone rubber Ecoflex by casting a template and curing it at room temperature. Then, evenly distributed circular through-holes with a diameter of 500 nm were generated on the film by mechanical punching, with a spacing of 1 mm between the holes.

[0068] Preparation of magnetically conductive fluid: The magnetically conductive fluid was prepared using ferric oxide. The preparation method was as follows: (1) Weigh an appropriate amount of PVA powder and dissolve it in deionized water to obtain a PVA solution with a concentration of 15 wt%. (2) Weigh 5.5 g of ferric oxide (particle size 100 nm, purity 99%), 11.5 g of PVA solution, and 0.2 g of additive (PVA crosslinker borax) and mix them to obtain a solvent, polymer, magnetic particles, and additive ratio of 56.83%, 10.03%, 31.98%, and 1.16%, respectively. Then, stir at 2000 rpm at room temperature for 2 minutes to ensure that all components are evenly mixed and complete the natural crosslinking of PVA, finally obtaining the magnetically conductive fluid.

[0069] Preparation of the encapsulation layer: A circular film with a thickness of 2 mm and a diameter of 6 cm was prepared using silicone rubber Ecoflex by casting a template and curing it at room temperature.

[0070] Electrode assembly: Take an appropriate amount of conductive electromagnetic fluid and place it between the flexible substrate and the packaging layer. Then fix the wires at the edge of the substrate and connect them to the conductive electromagnetic fluid and the collection device respectively. Then, bond the flexible substrate to the edge of the packaging layer to obtain a flexible electrode that can change position in real time.

[0071] Usage of electrodes: Clean the skin on the arm and attach the electrodes. Gently press the packaging layer area on the upper layer of the conductive electromagnetic fluid with your hand. After the conductive electromagnetic fluid is pressurized and contacts the skin through the holes in the flexible substrate, signal acquisition is performed when the arm makes a fist. After a single test, use a magnet to suck the conductive electromagnetic fluid back into the cavity space between the flexible substrate and the packaging layer through the holes in the flexible substrate, change the position of the conductive electromagnetic fluid in the flexible substrate and the packaging layer, and then press the conductive electromagnetic fluid through the holes in the flexible substrate to contact the skin. Signal acquisition is performed when the arm makes a fist again. After the final test, use a magnet to suck the conductive electromagnetic fluid out to the middle of the flexible substrate and the sealing layer.

[0072] (4.3) Example 3

[0073] Preparation of flexible substrate: A 5 mm thick, 6 cm diameter circular film was prepared using silicone rubber Ecoflex by casting a template and curing it at room temperature. Then, evenly distributed circular through-holes with a diameter of 1 mm were generated on the film by mechanical punching, with a spacing of 3 mm between the holes.

[0074] Preparation of magnetically conductive fluid: The magnetically conductive fluid was prepared using ferroferric oxide. The preparation method was as follows: (1) Weigh an appropriate amount of PVA powder and dissolve it in deionized water to obtain a PVA solution with a concentration of 20 wt%. (2) Weigh 4.46 g of ferroferric oxide (particle size of 100 nm, purity of 99%), 0.51 g of carbon nanotubes, 12 g of PVA solution, and 0.86 g of additive (PVA cross-linking agent borax) and mix them to obtain a solvent, polymer, magnetic particles, conductive material, and additive with a proportion of 53.84%, 13.46%, 25.01%, 2.86%, and 4.82%, respectively. The mixture was then stirred at 2000 rpm at room temperature for 2 minutes to ensure that the components were evenly mixed, and the magnetically conductive fluid was finally obtained.

[0075] Preparation of the encapsulation layer: A circular film with a thickness of 5 mm and a diameter of 6 cm was prepared by spin coating using a 10% mass fraction SEBS-toluene solution.

[0076] Electrode usage: Clean the skin on your back and attach the electrodes. Gently press the packaging layer area above the electromagnetic fluid with your hand. After the electromagnetic fluid is pressurized and contacts the skin through the holes in the flexible substrate, signal acquisition is performed while bending over. After a single test, a magnet is used to suck the electromagnetic fluid back into the cavity space between the packaging layer and the conductive fluid through the holes in the flexible substrate.

[0077] (4.4) Example 4

[0078] Figure 5 and Figure 6The following figure shows the myoelectric signals of the conductive electromagnetic fluid before and after the flexible electrode is used. Figure 5 and Figure 6 (a) in the figure is the electromyographic signal of channel 1. Figure 5 and Figure 6 (b) shows the EMG signal from channel 2. As can be seen from both figures, the EMG signal quality of both channels is high before and after the movement, and the signal morphology varies at different locations. The flexible electrode utilizes two conductive magnetic fluids.

[0079] However, in other embodiments, the number of conductive electromagnetic fluids within the flexible electrode cavity can be one, three, or more. Under a magnetic field or manual compression, the conductive electromagnetic fluid can be split from one into multiple pieces, and positioned to corresponding positions under the control of the magnetic field or external force, forming an electrophysiological signal acquisition array. This does not increase the complexity of the electrode due to the increase in the number of channels, thereby reducing equipment costs. Similarly, multiple conductive electromagnetic fluids can also be combined into one.

[0080] (4.5) Example 5

[0081] In the absence of needing to adjust the detection position, the conductive electromagnetic fluid in the flexible electrode cavity can be one, with an area that fills the cavity and a height that is sufficient to be sucked back into the cavity space from the hole.

[0082] The flexible electrode in this case can be used as a device or sensor for collecting physiological electrical signals, or as a local electrical stimulation device.

[0083] Although the embodiments of the present disclosure have been described above with reference to the accompanying drawings, the present disclosure is not limited to the specific embodiments and application areas described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. A person of ordinary skill in the art, guided by this specification and without departing from the scope of protection of the claims of the present disclosure, may devise various other forms, all of which fall within the scope of protection of the present disclosure.

Claims

1. A flexible electrode with real-time adjustable detection position, characterized by: The flexible electrode comprises an electromagnetically conductive fluid, a substrate, and an encapsulation layer, wherein the substrate and the encapsulation layer are combined to form a cavity, and the electromagnetically conductive fluid is confined within the cavity; The conductive magnetic fluid is a semi-solid conductive material that can be deformed and moved under the action of an external force or magnetic field; The substrate has holes. Pressing the surface of the packaging layer corresponding to the conductive electromagnetic fluid squeezes the conductive electromagnetic fluid, causing it to partially contact the skin through the holes to collect electrophysiological signals from the skin. The conductive electromagnetic fluid that has passed through the holes can return to the cavity space under the action of the magnetic field. The substrate is a flexible and stretchable polymer film, and its adhesion to the skin is not only greater than the gravity of the electrode itself, but also greater than the adhesion between the conductive electromagnetic fluid and the skin, thereby ensuring that the flexible electrode can stably collect signals under different skin conditions.

2. The flexible electrode according to claim 1, characterized in that: Use wires to connect the conductive fluid to external equipment.

3. The flexible electrode according to claim 1, characterized in that The components of the conductive magnetic fluid include solvent, polymer, magnetic particles, conductive material, and additives, with the mass proportions of each component being 35% to 65%, 2% to 18%, 15% to 40%, 0% to 25%, and 0.1% to 10%, respectively; the solvent is water or ethanol; the polymer is polyethylene glycol, dextran, polyvinyl pyrrolidone, or liquid silica gel; the magnetic particles are ferric oxide, ferroferric oxide, nickel, or rubidium iron boron powder; the conductive material is metal particles, carbon material, or conductive polymer; and the additive is a polymer crosslinker, glycerol, polyethylene glycol, sodium chloride, or potassium chloride.

4. The flexible electrode according to claim 1, wherein The material of the flexible and stretchable polymer film is one or more of the following composites: polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), isoprene-substituted butadiene block styrene polymer (SIS), and polyparaxylene.

5. The flexible electrode according to claim 1, wherein: The thickness of the flexible and stretchable polymer film is 100 nm-10 mm.

6. The flexible electrode according to claim 1, characterized in that The magnetic field is provided by magnets.

7. The flexible electrode according to claim 1, wherein: The holes are regular or irregular in shape or a combination of regular and irregular shapes, and the hole area is The distance between the edge of the hole and the adjacent hole is 0.1 μm-10 mm.

8. The flexible electrode according to claim 1, characterized in that There are multiple electromagnetically conductive fluids.

9. A flexible electrode, characterized in that: The flexible electrode comprises a cavity, the bottom of which adheres to the skin through its own physical action or adhesive; The cavity contains an electromagnetic fluid, which is a semi-solid conductive material that can deform and move under the action of external force or magnetic field. Pressing the cavity surface corresponding to the position where the electromagnetic fluid is located can make the electromagnetic fluid contact the skin through the holes at the bottom of the cavity, collect the electrophysiological signals of the skin, and the electromagnetic fluid that passes through the holes can return to the cavity space under the action of the magnetic field.

10. The flexible electrode according to claim 9, characterized in that: The bottom of the cavity is made of a flexible and stretchable polymer film, the adhesion force of which to the skin is not only greater than the gravity of the electrode itself, but also greater than the adhesion force of the conductive electromagnetic fluid to the skin.

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