Support assembly for detachable connection of bioelectric electrodes

Abstract

An electrode support assembly (1) for detachable connection of an electrode (2) for bioelectric signal acquisition, comprising a housing (3) and an electrode connector (4) having a connection device (42) on a first side (41) for detachable connection of the electrode (2) along an axial direction (A) of the housing (3), wherein the electrode connector (4) is movably connected to the housing (3) to allow movement of the electrode connector (4) relative to the housing (3) in a lateral direction (L) perpendicular to the axial direction (A) of the housing (3), wherein the electrode support assembly (1) further comprises a bearing (5) allowing lateral movement of the electrode connector (4), the bearing (5) comprising a plurality of balls preferably held in a bearing cage.

Description

Technical Field

[0001] This invention relates to an electrode support assembly for detachably connecting bioelectric electrodes for acquiring bioelectric signals. The electrode support assembly includes a housing and an electrode connector. The housing defines an internal space with an opening in the axial direction of the electrode support assembly. The electrode connector is housed within the housing and has a connection device on a first side for detachably connecting the electrode. Background Technology

[0002] Bioelectrical signals are among the most fundamental physiological signals in the human body. Flexible dry electrodes (SDEs)—a type of bioelectrical electrode—are increasingly used to acquire bioelectrical signals in applications such as electroencephalography (EEG), electrocardiography (ECG), or electromyography (EMG). A common problem with any measurement is so-called artifacts, which are phenomena that may be observed in scientific research or experiments and are not naturally occurring but rather a result of the preparation or investigation process. Therefore, motion artifacts are various noises or interferences in the recorded signal caused by electrode movement on an individual's skin or poor electrode-skin contact.

[0003] So-called flexible dry electrodes (SDEs) typically consist of electrode bodies made of conductive elastomers, offering high wearing comfort due to the material's flexibility. Simultaneously, dry signal acquisition can be achieved without the need for conductive gel, thus reducing preparation time and further improving wearing comfort. Because flexible dry electrodes are directly attached to the skin, noise reduction cannot be achieved by using conductive gel. Motion artifacts can occur when a person moves or is in motion. Therefore, the (flexible dry) electrode may shift relative to the skin and thus lose proper contact, leading to a significant degradation in signal quality, making signal analysis and interpretation more difficult and less reliable. This effect can be particularly pronounced when the electrode is attached to a more rigid structure (e.g., headphones). Therefore, reducing motion artifacts in electrode-based applications is necessary.

[0004] WO202326202 and WO202204408 disclose a brain signal sensing headset with a relatively large and complex electrode device. The electrodes are pivotable relative to the headset's support structure, allowing them to make full contact with the surface of the subject's head. This electrode device does not compensate for lateral or radial movement. Motion artifacts are not reduced.

[0005] EP4014866 discloses an electrode device with a rather large and complex structure. This electrode device includes an electrode component with several styluses, a support shaft component for supporting the electrode component, a frame component for slidably holding the support shaft component along its axial direction, and a spring-shaped elastic component for biasing the electrode component outwards along the axial direction of the support shaft component. This electrode device does not compensate for lateral or radial movement. Motion artifacts are not reduced.

[0006] EP3373802 / WO2017083826 discloses an electrode device in which electrodes are pivotable relative to a support structure, such that the electrodes are in full contact with the surface of a subject's head. The support structure has three arms, each with an electrode at its end. The support structure is adjustable relative to a headset to position the electrodes in a desired location and then locked. The electrode device does not compensate for lateral or radial movement during measurement. Motion artifacts are not reduced.

[0007] US2022273470 describes an electrode assembly for an electromyographic prosthesis that mounts at least one electrode using at least one biasing element, thereby allowing movement of at least one electrode to be at least partially decoupled from the electrode housing and from the prosthesis receiving cavity. This at least partial decoupling of movement is achieved through a rather complex system requiring one or more elastically deformable biasing bands. Summary of the Invention

[0008] The purpose of this invention is to provide an electrode support assembly and an electrode device for bioelectrical signal acquisition, exhibiting reduced motion artifacts. At the same time, the support assembly and device have a simple, compact, and lightweight design that does not unnecessarily increase the cost and size of the measurement equipment.

[0009] At least one object of the present invention is achieved by the electrode support assembly according to claim 1 and the electrode device according to claim 14.

[0010] An electrode support assembly for detachably connecting electrodes for acquiring bioelectrical signals includes a housing and an electrode connector. The electrode connector has a connecting means on a first side for detachably connecting the electrode along the axial direction of the housing. The electrode connector is movably connected to the housing to allow movement of the electrode connector relative to the housing in a lateral (or radial) direction perpendicular to the axial direction of the housing. The electrode support assembly further includes a bearing that allows lateral movement of the electrode connector, and the bearing includes a plurality of balls preferably held in a cage.

[0011] The proposed electrode support assembly reduces lateral motion artifacts arising from relative movement of the electrodes relative to the skin in a direction approximately parallel to the skin surface. Relative movement can be compensated for by allowing a degree of freedom within the electrode support assembly in the lateral X and Y directions (perpendicular to the axial direction A) (i.e., along the skin surface), such that only the housing moves while the electrodes remain in a predetermined position. The operating principle can be based on the support surface (e.g., the flat back of a concave snap-fit ​​connection for the electrodes) sliding on a bearing (e.g., balls fixed in a ball bearing cage) housed within the housing. Rotation about the axial direction is also possible.

[0012] Further embodiments of the present invention are described in the dependent claims.

[0013] In some embodiments, the housing may define an internal space having an opening in the axial direction of the electrode support assembly, and the electrode connector may be accommodated in the housing in a laterally movable manner.

[0014] In some embodiments, the electrode support assembly may further include a bearing that allows or facilitates lateral movement of the electrode connector and is housed and retained within the interior space of the housing. The electrode connector may have a support surface abutting the bearing on a second side opposite the first side, wherein the interior space and opening dimensions of the housing are configured such that the electrode connector can move laterally within the interior space.

[0015] Therefore, in embodiments of the present invention, an electrode support assembly for detachably connecting electrodes for bioelectrical signal acquisition includes: a housing defining an internal space with an opening in the axial direction of the electrode support assembly; and an electrode connector housed in the housing and having a connection means on a first side for detachably connecting the electrode. The electrode support assembly further includes a bearing housed and held within the internal space of the housing. The electrode connector has a support surface abutting the bearing on a second side opposite to the first side. The internal space and opening dimensions of the housing are configured such that the electrode connector can move laterally within the internal space (i.e., perpendicular to the axial direction of the electrode support assembly).

[0016] The internal space and opening size of the housing can be configured such that the relative lateral movement of the electrode connector, and thus the final electrode, relative to the housing is at least 1 mm from the center position, preferably at least 2 mm, and more preferably at least 5 mm.

[0017] In some embodiments, the bearing may include a plurality of balls held in a ball bearing cage. The ball bearing cage may be an annular ball bearing cage having an axially central opening that allows electrical contact with electrodes, for example, via wires.

[0018] In some embodiments, the electrode connector has a disc-shaped support plate that forms a support surface on a second side and includes a connecting device on an opposing first side. The diameter of the support plate may be smaller than the diameter of the internal space but larger than the diameter of the opening.

[0019] In some embodiments, the opening of the housing may have a smaller diameter than the internal space of the housing, and the support surface of the electrode connector may have a larger diameter than the opening. Thus, the electrode connector can be held within the housing without any additional locking mechanism. The diameters of the opening and the internal space also define the range of relative movement of the electrode connector, and consequently the electrode ultimately connected to the electrode connector, relative to the housing.

[0020] In some embodiments, the housing may include a housing body forming an internal space and a housing cover forming an opening. The housing or housing body may be a separate component attached to a supporting device (e.g., headphones), or it may be an integral part of the supporting device. The cover may be attached to the housing body by screws or otherwise.

[0021] In some embodiments, the electrode connector may be at least partially housed and held within the interior space of the housing. This holding can be achieved through appropriate dimensions of the interior space, the opening, and the electrode connector itself.

[0022] In some embodiments, the connection means of the electrode connector can be accessed by the electrodes through an opening in the housing. The connection means may be arranged within the interior space of the housing, or may be arranged within or extend through the opening of the housing. When the connection means is located within or extends through the opening, it has a smaller diameter than the opening to allow lateral movement of the electrode connector.

[0023] In some embodiments, the housing may include a through-hole opposite the opening and / or the electrode connector may include a through-hole on a second side, the through-hole being adapted for electrically connecting the electrode to the measuring device.

[0024] In some implementations, the internal space can be designed to allow for a gap in the axial direction of the electrode connector. This gap can be in the range of 0.5-3 mm.

[0025] The bearing abuts against the inner wall of the internal space opposite the opening. In some embodiments, the inner wall may be provided with a recess that serves as a raceway to accommodate a bearing, for example, in the form of a ball bearing, to prevent lateral movement of the ball bearing cage. The axial clearance of the electrodes in the internal space should not be too large to prevent the ball bearing from falling out of the recess.

[0026] In some embodiments, the electrode connector's connection device may be part of a snap-fit ​​or snap-fit ​​connector, preferably in the form of a snap or button fastener, for connecting the corresponding connection device of the electrode.

[0027] In some embodiments, the housing and electrode connector are made of non-conductive material, preferably plastic.

[0028] The present invention further relates to an electrode device for acquiring bioelectric signals, comprising an electrode support assembly and a bioelectric electrode as described above, preferably a flexible dry electrode.

[0029] In some embodiments, the electrode may include a conductive electrode body having connection means on the connector side for connecting the electrode to an electrode connector of an electrode support assembly.

[0030] In some implementations, the electrode may include a contact side opposite to the connector side for contacting a target area of ​​the human body.

[0031] In some embodiments, the contact side of the electrode may be provided with a plurality of flexible contact pins.

[0032] When the electrode device is in use, the electrodes (preferably flexible dry electrodes) are detachably connected to the electrode support assembly via the electrode connector's connection means. The electrode device, for example, as part of a headset, is then placed on a target human body. Thus, by applying force towards the human body, the electrodes contact the target area of ​​the human body. When the human body moves, the headset may also move relative to the target area. Due to the lateral freedom of the electrode connector, the electrodes can remain in the same position without the risk of losing proper contact with the human skin. Motion artifacts are reduced, and signal quality is significantly improved. Attached Figure Description

[0033] The present invention will now be described in more detail with reference to the embodiments shown in the accompanying drawings. The drawings show:

[0034] Figure 1 This is a perspective view of the electrode support assembly as seen from the first side;

[0035] Figure 2 It is viewed from the opposite second side. Figure 1 A perspective view of the electrode support assembly;

[0036] Figure 3 yes Figure 1 A cross-sectional view of the electrode support assembly together with the electrode;

[0037] Figure 4 yes Figure 1 Exploded view of the electrode support assembly together with the electrodes as viewed from the first side;

[0038] Figure 5 yes Figure 1 Exploded view of the electrode support assembly together with the electrodes as viewed from the second side;

[0039] Figure 6 shows the raw data measurements obtained from the forearm during human activity with or without the electrode support assembly (a) or (b);

[0040] Figure 7 shows the raw data measurements obtained from an inactive forearm of a human body with or without the electrode support assembly (a) or (b). Detailed Implementation

[0041] Figure 1 and Figure 2 A perspective view of electrode support assembly 1 for detachably connecting electrodes for acquiring bioelectrical signals is shown. Figures 3 to 5 Shown in different views Figure 1 or Figure 2 The electrode support assembly 1 includes a flexible dry electrode 2.

[0042] The electrode support assembly 1 includes a housing 3, which, in the illustrated embodiment, is formed by a housing body 33 and a housing cover 34. The housing 3 may be a separate component connected to another structure of the measuring device used to measure bioelectrical signals. The housing or housing body may also be an integral part of the support structure of the measuring device (e.g., a headset). The housing body 33 and housing cover 34 may be connected to each other, for example, by screws 6.

[0043] The housing 3 forms an internal space 31, which has an opening 32 along the axial direction A of the electrode support assembly 1. Thus, the internal space 31 can be formed by the housing body 33, and the opening 32 can be formed by the housing cover 34. Opposite to the opening, the housing 3 or the housing body 33 is provided with a through hole 35 for electrically connecting the electrode through a wire.

[0044] The electrode support assembly 1 further includes an electrode connector 4 and a bearing 5, both of which are housed and held within the internal space 31 of the housing 3. The bearing 5 allows lateral movement (direction L) of the electrode connector 4 relative to the housing 3 and may be a ball bearing with an annular ball cage having a central through-hole. The bearing 5 abuts against the inner wall of the internal space 31 opposite the opening 32. This inner wall may be provided with a recess 36 for accommodating the bearing 5 to prevent lateral movement of the bearing 5.

[0045] In the illustrated embodiment, the electrode connector 4 includes a support plate 45 having a first side 41 and a second side 43 opposite to the first side 41. The electrode connector 4 further includes a connecting device 42 (in the illustrated embodiment, in the form of a snap-fit ​​connector) centrally disposed on the first side 41 of the support plate 45. The second side 43 of the support plate 45 forms a support surface 44 that abuts against a bearing 5 when the electrode support assembly is in use. Due to the presence of the bearing 5, the electrode connector 4 can rotate freely about the axial direction A.

[0046] The dimensions of the internal space 31 and opening 32 of the housing 3 are configured such that the electrode connector 4, together with the connected electrode 2, can move freely in the lateral direction L. Thus, even when the human body moves, the electrode 2 remains at the target area of ​​the human skin. Relative movement of the housing 3 relative to the human skin can be compensated. The possible lateral movement is preferably at least 2 mm from the center of the opening 32, more preferably at least 5 mm. Meanwhile, the dimensions of the internal space 31 can be configured such that the support plate 45 has some clearance or gap in the axial direction within the internal space 31, preferably about 1-3 mm.

[0047] In the illustrated embodiment, electrode 2 is a flexible dry electrode 2 having a conductive electrode body 21 made of an elastomeric material. This conductive electrode body has a connecting device 22 on the connector side of electrode 2 and a plurality of flexible contact pins 23 on the opposite contact side of electrode 2. The connecting devices 22 and 42 between electrode 2 and electrode connector 4 are part of a snap-fit ​​or snap-fit ​​connector, preferably in the form of a snap or button fastener.

[0048] To electrically connect electrode 2 to the measuring device, housing 3 and electrode connector 4 are each provided with through holes 35 and 46 for applying wire connections. Through holes 35 and 46 are centrally arranged along the axial direction A of electrode support assembly 1. Bearing 5 has a central opening to provide sufficient space for the wires even when electrode connector 4 moves laterally relative to housing 3.

[0049] Figures 6 and 7 show comparative raw data measurements of bioelectrical signals (amplitude in µV) over time (in seconds) recorded from an active forearm (Figure 6) or an inactive forearm (Figure 7) of a human body. In the case of an active forearm, the hand was repeatedly clenched and reopened.

[0050] In each case, comparative measurements were performed in parallel with and without the aforementioned electrode support assembly (Figure 6(a) or Figure 7(a)). Therefore, both the electrode with and without the aforementioned electrode support assembly (i.e., the standard connector) were fixed to a rigid element to undergo the same conditions on the forearm. A reference electrode was placed approximately 5 cm from both measuring electrodes.

[0051] Figure 6 shows the comparative measurements of the active forearm during repeated opening and closing of the hand. Figure 7 shows the comparative measurements of the inactive, stationary forearm (i.e., without repeated opening / closing of the hand).

[0052] In both cases, motion artifacts can be significantly reduced by using the electrode support assembly described above.

[0053] List of reference numerals

[0054] 1 Electrode support assembly

[0055] 2. Bioelectric electrodes

[0056] 21 Electrode Body

[0057] 22 Connecting device

[0058] 23 Flexible styluses

[0059] 3. Shell

[0060] 31 Interior Space

[0061] 32 Opening

[0062] 33. Main body of the shell

[0063] 34. Housing cover

[0064] 35 through hole

[0065] 36 recess

[0066] 4 Electrode Connectors

[0067] 41 First side

[0068] 42 Connecting device

[0069] 43 Second side

[0070] 44 Support surface

[0071] 45 Support plate

[0072] 46 Through Holes

[0073] 5. Bearings (ball bearings)

[0074] 6 screws

[0075] Axial direction

[0076] L (horizontal direction)

Claims

1. An electrode support assembly (1) for detachably connecting an electrode (2) for acquiring bioelectric signals, comprising a housing (3) and an electrode connector (4), the electrode connector having a connecting device (42) on a first side (41) for detachably connecting the electrode (2) along the axial direction (A) of the housing (3), characterized in that, The electrode connector (4) is movably connected to the housing (3) to allow the electrode connector (4) to move relative to the housing (3) in a lateral direction (L) perpendicular to the axial direction (A) of the housing (3). The electrode support assembly (1) further includes a bearing (5) that allows the electrode connector (4) to move laterally, and the bearing (5) includes a plurality of balls preferably held in a bearing cage.

2. The electrode support assembly (1) according to claim 1, wherein, The housing (3) defines an interior space (31) having an opening (32) in the axial direction (A) of the electrode support assembly (1), and wherein the electrode connector (4) is accommodated in the housing (3).

3. The electrode support assembly according to claim 2, wherein, The bearing (5) is housed and held within the internal space (31) of the housing (3), and the electrode connector (4) has a support surface (44) abutting the bearing (5) on a second side (43) opposite to the first side (41); wherein the dimensions of the internal space (31) and the opening (32) of the housing (3) are configured such that the electrode connector (4) can move in the lateral direction (L) within the internal space (31).

4. The electrode support assembly according to claim 3, wherein, The bearing cage is an annular ball bearing cage, which preferably has an axial central opening that allows electrical contact with the electrodes.

5. The electrode support assembly according to any one of claims 3 or 4, wherein, The electrode connector (4) has a disc-shaped support plate (45) forming the support surface (44) on the second side (43) and including the connecting device (42) on the opposite first side (41).

6. The electrode support assembly according to any one of claims 2 to 5, wherein, The opening (32) of the housing (3) has a smaller diameter than the internal space (31) of the housing (3), and the support surface (44) of the electrode connector (4) has a larger diameter than the opening (32).

7. The electrode support assembly according to any one of claims 2 to 6, wherein, The housing (3) includes a housing body (33) forming the internal space (31) and a housing cover (34) forming the opening (32).

8. The electrode support assembly according to any one of claims 2 to 7, wherein, The electrode connector (4) is at least partially housed and held within the internal space (31) of the housing (3).

9. The electrode support assembly according to any one of claims 2 to 8, wherein, The connection device (42) of the electrode connector (4) can be accessed through the opening (32) of the housing (3).

10. The electrode support assembly according to any one of claims 2 to 9, wherein, The connecting device (42) of the electrode connector (4) is arranged in or extends through the opening (32) of the housing (3).

11. The electrode support assembly according to any one of claims 2 to 10, wherein, The housing (3) includes a through hole (35) opposite to the opening (32) and / or the electrode connector (4) includes a through hole (46) on the second side (43), the through holes (35, 46) being adapted for electrically connecting the electrode (2) to a measuring device.

12. The electrode support assembly according to any one of claims 2 to 11, wherein, The internal space (31) is designed such that the electrode connector (4) has a gap in the axial direction (A).

13. The electrode support assembly according to any of the preceding claims, wherein, The connecting device (42) of the electrode connector (4) is part of a snap-fit ​​or snap-fit ​​connector, preferably in the form of a snap or button fastener, for connecting the corresponding connecting device of the electrode (2).

14. An electrode device comprising an electrode support assembly (1) and a bioelectric electrode (2) as described in any of the preceding claims, preferably a flexible dry electrode.

15. The electrode device according to claim 14, wherein, The electrode (2) includes a conductive electrode body (21), which has a connection device (22) on the connector side for connecting the electrode (2) to the electrode connector (4) of the electrode support assembly (1).

16. The electrode device according to any one of claims 14 to 15, wherein, The electrode (2) includes a contact side opposite to the connector side, the contact side being used to contact a target area of ​​the human body.

17. The electrode device according to any one of claims 15 to 16, wherein, The electrode (2) is provided with a plurality of flexible styluses (23) on the contact side.

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