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JP-7856632-B2 - Soft dry electrode

JP7856632B2JP 7856632 B2JP7856632 B2JP 7856632B2JP-7856632-B2

Inventors

  • ロニー、フライエンス
  • マッティア、アルベルト、ルッキーニ
  • ラファエル、ケリン
  • ミヒャエル、ゼゲッセンマン

Assignees

  • デトワイラー、シュバイツ、アーゲー

Dates

Publication Date
20260511
Application Date
20210819
Priority Date
20200903

Claims (16)

  1. A soft electrode (1) for measuring the bioelectrical signals of an individual, When the electrode (1) is applied to the individual, the contact side (21) facing the individual, The support (2) comprises a connector side (22) opposite to the contact side (21), The support (2) further defines a central axis (A) located in the center, passing through the contact side (21) and the connector side (22), The electrode (1) further comprises a plurality of external contact pins (3) located in the radially external region (23) of the support (2) in order to contact the measurement target range. The plurality of external contact pins (3) are supported and arranged on the contact side (21) of the support (2), The electrode (1) is a soft electrode (1) made of an elastomer material and having conductive properties, The support (2) is a dome-shaped disk having a concave side (21a) and a convex side (22b), the concave side (21a) forming the contact side (21) of the support (2), The support (2) is designed to be flexible such that, after the electrodes are applied to the solid, a force applied to the connector side (22) centrally and parallel to the central axis (A) causes the radially outer region (23) of the dome-like disk (2) to bend upward toward the connector side (22). A soft electrode (1) characterized in that bending the radially outer region (23) of the dome-like disk (2) upward leads to tilting the plurality of external contact pins (3) with respect to the central axis (A) such that the tips (31) of the external contact pins (3) move radially outward along the target range of the individual.
  2. The soft electrode according to claim 1, characterized in that the vertical axis (P) of each of the plurality of external contact pins (3) is parallel to the central axis (A).
  3. The soft electrode according to claim 1 or 2, further comprising a plurality of internal contact pins (4), the electrode (1) being located in an internal region (24) of the support (2) that is closer to the central axis (A) than the external region (23) of the support (2), and having dimensions such that it contacts the solid after the external contact pins (3) have been tilted.
  4. The flexible electrode according to claim 3, characterized in that the plurality of external contact pins (3) and the plurality of internal contact pins (4) have the same length.
  5. The flexible electrode according to claim 3 or 4, characterized in that the plurality of external contact pins (3) and the plurality of internal contact pins (4) are arranged and sized such that, while the electrode (1) is applied to the solid, the plurality of external contact pins (3) contact the target area in front of the plurality of internal contact pins (4).
  6. The flexible electrode according to any one of claims 3 to 5, characterized in that the plurality of internal contact pins (4) each have a conical base and a cylindrical free end.
  7. The flexible electrode according to any one of claims 1 to 6, characterized in that the plurality of external contact pins (3) each have a conical base and a cylindrical free end.
  8. The soft electrode according to any one of claims 1 to 7, characterized in that the support (2) is a circular disk (25).
  9. The flexible electrode according to any one of claims 1 to 8, characterized in that a knob (28) for electrically connecting the electrode (1) to an electronic circuit is provided on the connector side (22) of the support (2).
  10. The soft electrode according to any one of claims 1 to 9, characterized in that the tips (31) of the plurality of external contact pins (3) have inclined surfaces facing toward the central axis (A) of the support (2).
  11. The flexible electrode according to any one of claims 1 to 10, characterized in that the elastomer material of the electrode (1) is a thermosetting elastomer or a thermoplastic elastomer.
  12. The soft electrode according to any one of claims 1 to 11, characterized in that the electrode is formed as an integrally molded part.
  13. A soft electrode (1) for measuring the bioelectrical signals of an individual, The electrode (1) is When the electrode (1) is applied to the individual, the contact side (21) facing the individual, The support (2) comprises a connector side (22) opposite to the contact side (21), The support (2) further defines a central axis (A) located in the center, passing through the contact side (21) and the connector side (22), The electrode (1) further comprises a plurality of external contact pins (3) located in the radially external region (23) of the support (2) in order to contact the measurement target range. The plurality of external contact pins (3) are supported and positioned on the contact side (21) of the support (2). The electrode (1) is a soft electrode (1) made of an elastomer material and having conductive properties, The support (2) has a dome-like shape with a concave side (21a) and a convex side (22b), and the concave side (21a) forms the contact side (21) of the support (2). The support (2) is designed to be flexible such that, after the electrode is applied to the solid, a force applied towards the connector side (22) towards the center and parallel to the central axis (A) causes the radially outer region (23) of the support (2) to bend upward toward the connector side (22). Bending the radially outer region (23) of the support (2) upward results in tilting the plurality of external contact pins (3) with respect to the central axis (A) such that the tips (31) of the external contact pins (3) move radially outward along the target area of the individual, The soft electrode is characterized in that the support (2) comprises a central disk having a plurality of legs (27) that are radially outward at an angle of less than 90 degrees with respect to the central axis (A) and define the outer region (23) of the dome-shaped support (2), the plurality of external contact pins (3) are arranged at the free ends of the legs (27), and the longitudinal axis (P) of each of the plurality of external contact pins (3) is parallel to the central axis (A).
  14. The soft electrode according to claim 13, characterized in that the angle with respect to the central axis (A) is between 30 and 70 degrees.
  15. The flexible electrode according to claim 13 or 14, characterized in that the plurality of external contact pins (3) each have a conical base and a cylindrical free end.
  16. The soft electrode according to claim 13 or 15, characterized in that the tips (31) of the plurality of external contact pins (3) have inclined surfaces facing the central axis (A) of the support (2).

Description

This invention relates to a flexible, dry electrode for detecting bioelectrical signals in applications such as electroencephalography (EEG), electrocardiogram (ECG), or electromyography (EMG). Commercially available "dry" EEG headsets often feature metal dry electrodes, causing pain to subjects after wearing the headset for an extended period. A possible solution is to combine these electrodes with a spring-like system to avoid high skin pressure. Another approach involves the use of flexible polymer-based dry electrodes. By mixing elastic polymers with additives, conductivity can be improved while maintaining the elasticity necessary for high user comfort. Polymer-based dry electrodes may have a comb-like design (fingers or legs) to improve skin contact on hairy skin (e.g., scalp). Such fingers or legs may have at least partial coatings on the surface of the electrode in contact with the skin to reduce skin impedance and provide improved signal quality. Therefore, flexible, dry electrodes are increasingly used for long-term biopotential measurements such as EEG and ECG. In addition to being flexible, the fact that such electrodes can be applied without the use of conductive gels provides significant advantages to the measurement procedure, including a reduced risk of skin irritation and avoidance of signal quality degradation due to gel drying. Examples of such flexible dry electrodes are described in Chen et al.'s "Polymer-Based Dry Electrodes for User-Comfortable ECG/EEG Measurement" (Chen, Yun-Hsuan; Op de Beeck, Maike; Carrette, Evelien; Vanderheyden, Luc; Grundlehner, Bernard; Mihajlovic, Vojkan; Boon, Paul; Van Hoof, Chris; Apprimus) Verlag; Aachen; 8th International Conference and Exhibition on the Integration of Miniaturized Systems – MEMS, NEMS, ICs and Electronic Components; 2014; pp. 329–336), and also described by Chen et al., “Flexible and Comfortable Polymer Dry Electrodes for High-Quality ECG and EEG Recording” (Sensors 2014, 14, 23758–23780; doi: 10.3390/s141223758) or WO2016080804. These flexible dry electrodes comprise a substrate and a plurality of pins for contacting the measurement area. The pins may have tapered and projection portions. The electrode tips are made of a flexible or soft matrix material with a conductive material provided. The electrodes may have a knob on the upper side of the substrate opposite the pins for electrically connecting the electrodes. When force is applied to a soft electrode (e.g., by a strap, band, headset, or head cap), the leg portion may move uncontrollably, failing to provide the intended brushing function for moving hair to the side and potentially causing direct contact between the electrode and the skin surface. One possible solution to this problem is the pre-orientation of the electrodes (as described in EP2827770) such that when the electrodes are applied to the target area (e.g., the scalp), the electrodes are positioned at a non-perpendicular angle to that area. However, a drawback of this method is the adopted manufacturing process, which involves a 3D printing step that is not suitable for scaling up for mass production. JP20190977332 relates to electrodes for measuring brain activity. The electrodes have a rigid support and several arms attached to the sides of the rigid support. A bulbous portion is formed at the end of the arms to contact the human scalp. The arms are flexible and bend when force is applied to the electrodes. Because the electrodes have a complex shape with several notches, they are difficult to manufacture in a cost-effective manner. These are bottom view (a), side view (b), and perspective view (c) of an electrode having a dome-shaped circular disc.These are cross-sectional views of the electrode in Figure 1 before (a) and after (b) force is applied to the electrode.These are a bottom view (a), a side view (b), and a perspective view (c) of an electrode having a dome-shaped support with legs.These are cross-sectional views of the electrode in Figure 3 before (a) and after (b) force is applied to the electrode. Figure 1 shows a bottom view (a), side view (b), and perspective view (c) of a soft, dry electrode 1 for measuring the bioelectrical signals of an individual. Figure 2 shows cross-sectional views of the electrode in Figure 1 before (a) and after (b) force is applied to the electrode. The electrode 1 is made from an elastomer material that is provided with a conductive additive and/or at least partially coated with a conductive coating. The electrode 1 is formed as a single piece and comprises a dome-shaped support 2, several external contact pins 3, and several internal contact pins 4. The support 2 forms a concave contact side 21 for supporting the contact pins 3 and 4 for contacting a solid, and a convex connector side 22 opposite the contact side 21. The connector side 22 is provided with a connector knob 28 for electrically connecting the electrode 1 to an electronic circuit. The support 2 defines a central