WO2008067839A1 - Dry electrode cap for electro-encephalography - Google Patents

Dry electrode cap for electro-encephalography Download PDF

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Publication number
WO2008067839A1
WO2008067839A1 PCT/EP2006/011843 EP2006011843W WO2008067839A1 WO 2008067839 A1 WO2008067839 A1 WO 2008067839A1 EP 2006011843 W EP2006011843 W EP 2006011843W WO 2008067839 A1 WO2008067839 A1 WO 2008067839A1
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WO
WIPO (PCT)
Prior art keywords
electrodes
electrode cap
cap according
electrode
joint
Prior art date
Application number
PCT/EP2006/011843
Other languages
French (fr)
Inventor
Florin Popescu
Siamac Fazli
Yakob Badower
Klaus R. Mueller
Original Assignee
Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. filed Critical Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority to PCT/EP2006/011843 priority Critical patent/WO2008067839A1/en
Priority to EP06840965.5A priority patent/EP2101640B1/en
Priority to US12/517,664 priority patent/US8548554B2/en
Priority to ES06840965T priority patent/ES2409734T3/en
Priority to JP2009539609A priority patent/JP5367579B2/en
Publication of WO2008067839A1 publication Critical patent/WO2008067839A1/en

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/68Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6802Sensor mounted on worn items
    • A61B5/6803Head-worn items, e.g. helmets, masks, headphones or goggles
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/24Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
    • A61B5/25Bioelectric electrodes therefor
    • A61B5/279Bioelectric electrodes therefor specially adapted for particular uses
    • A61B5/291Bioelectric electrodes therefor specially adapted for particular uses for electroencephalography [EEG]
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/68Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6813Specially adapted to be attached to a specific body part
    • A61B5/6814Head

Definitions

  • the invention relates to an electrode cap for electro-encephalography which allows contacting the head of a human or an animal without a conductive gel between the scalp and the electrode itself.
  • This wet electrode requires gel to be applied between the skin and the electrode to allow for the exchange of ions at the interface.
  • the use of such a gel is inconven- ient for a daily use of the electrodes: it requires a time consuming preparation before any EEG recording can be carried out; the gel dries with the passing of time and thus needs to be refilled in long applications of the electrodes to the scalp. It has also been reported that long term contact with the skin produces irritation.
  • EEG data An alternative approach to the collection of EEG data is the use of sensors that operate with current dis- placement, that is a capacitive transduction, instead of charge current, as was the case for the previous example .
  • These types of electrodes do not require physical contact to the signal source.
  • the advantage of independence of contact with the body brings along the disadvantage that the background noise recorded along with the physiological signals is higher.
  • NASICON acronym for Na Super Ionic Conductor
  • the particular propriety of interest of the NASICON (acronym for Na Super Ionic Conductor) material is its very high conductivity of Na + ions even at room temperature.
  • the downside of using this material is a higher impedance mismatch with the skin than the common wet electrodes .
  • Microfabrication technology has produced good results in miniaturization of real size sensors.
  • Griss et al developed a dry electrode that avoids the use of electrolytic gel and at the same time fixes the electrode to the skull surface with enough reliability to avoid motion artifacts, making use of microfabricated spikes on the electrode surface (Griss, P et al . , "Characterization of micro- machined spiked biopotential electrodes" , Biomedical Engineering, IEEE Transactions on Volume 49, Issue: 6 June 2002) .
  • the spikes prickle the outer layers of the skin but avoid penetrating the dermis, where nerves and blood vessels are. This way, pain- free measurements of potentials is achieved, avoiding the high impedance from the outer skin layers.
  • Another solution makes use of carbon nanotubes.
  • a population of carbon nanotubes are used as probes that, in pricking the sur- face layers of the dermis, behave as the transducers themselves .
  • the present invention is based on the idea that an optimal result of an electroencephalography measure- ment (EEG) together with a maximum of wearing comfort for the patient is achieved if the force that each pin exerts on the scalp of the patient is uniform for all electrodes or groups of electrodes and can be adjusted.
  • EEG electroencephalography measure- ment
  • this is achieved by mounting or supporting the electrodes on an electrode holding means through at least one elastic joint.
  • the electrodes push down onto the surface of the scalp by means of an elastic force, as for exam- pie that of a spring or of pneumatic pressure.
  • the electrode holding means preferably comprises a head- fixing means, such as for example an adjustable head strap which tightens around the forehead, side and back of the head and allows to fix the electrode cap to the head with adjustable pressure.
  • a head- fixing means such as for example an adjustable head strap which tightens around the forehead, side and back of the head and allows to fix the electrode cap to the head with adjustable pressure.
  • the electrodes are mounted on the electrode holding means through one or more connecting means which preferably are or comprise a small number, for example 2 to 30, holding arms. As many arms can be used as can be fit without interfering with each other physically. Those holding arms are fixed to the head fixing means or head strap with one end while the other end carries the electrodes.
  • the electrodes can be attached to the holding arms directly or indirectly through other components.
  • the holding arms comprise two legs which are connected with each other through an elastic joint.
  • the lower part of the arm that is the leg which is connected to the head fixing means, is called electrode arm support.
  • an electrode arm moving beam that is the leg which carries the electrodes, is attached by means of a revolute or prismatic joint.
  • a revolute or prismatic joint Preferably, this allows the distal end of the arm to move perpendicularly to the surface of the scalp.
  • the legs of the arms are straight they preferably include an angle which opens in the direction of the head.
  • the elastic joint between the legs of an arm can be a revolute joint or a pivotal joint of which the rotation axis is perpendicular to the length of the legs and tangential to the head.
  • a torque-producing flexing cord or a similarly adjustable torsional spring is stretched between pairs of adjacent legs of an arm which are connected with each other by an elastic joint. This allows to apply a bending moment around this elastic joint which connects the two legs. By adjusting the length of such a cord or spring, the pressure which the electrodes apply to the scalp of the head can be adjusted.
  • the cord or spring may have a certain elastic stiffness K E A FC and zero point X OEA F C either of which may be adjustable by hand via a tightening screw or a geared mechanism.
  • the joint between two adjacent legs is a prismatic joint which is preferably movable in the direction of the head of the patient .
  • a prismatic joint comprises a bore or cylinder in one leg in which a part of the other leg is guided in one direction, for example the direction of the length of the leg.
  • a spring or some other flexible element can be arranged, which expands or contracts if the legs are moved against each other. It is furthermore possible to connect two neighbouring legs of an arm by a flexing chord, similarly as outlined for the pivotal joint, above. By this a force is applicable in the direction in which the prismatic joint is movable . This force can act in the direction of the elastic force of the elastic element or in the opposite direction. By adjusting the length of such a cord, the pressure which the electrodes apply to the scalp of the head can be adjusted.
  • This cord also may have a certain elastic stiffness K E AF C and zero point Xo EAF c either of which may be adjustable by hand via a tightening screw or a geared mechanism.
  • the individual electrodes are grouped into groups whereby each group comprises a part of the electrodes .
  • the number of electrodes in each group is preferably equal but can also be different.
  • Electrodes which belong to the same group are held by a common group holding means which holds all electrodes of this group.
  • the group holding means are each mounted directly or indirectly on the electrode holding means through at least one elastic joint.
  • this holding means can be an electrode holding arm wherein the different legs are connected through elastic joints.
  • the group holding means preferably comprise at least one elastic joint through which they are mounted on the electrode holding means or the holding arm.
  • an elastic joint can be a semi-rigid spherical joint or a virtual ball joint which is an elastic structure which, through its elasticity, provides the same mo- tion as a ball joint on the distal end of a leg attached to the joint. Its response to deflections is equivalent to that of a spring-loaded ball joint.
  • Such a joint can be movable around a first axis parallel to the length of the electrodes, i.e. parallel to the direction of the force by which the electrodes are pressed against the head. For this direction, the joint then has a certain torsional stiffness K 3 .
  • the joint is movable around at least one axis perpendicular to the direction in which the force acts which applies pressure to the head.
  • the joint has a torsional stiffness K ⁇ . If the joint is movable around an axis perpendicular to the length of the electrodes, the surface which is described by the tips of the electrodes can adjust its orientation to the slope of the head at the position where the electrodes are applied. It is preferred that the torsional stiffness around the axis perpendicular to the length of the electrodes K ⁇ is considerably greater than the torsional stiffness K 3 around the axis par- allel to the length of the electrodes. By this, the group holding means can be prevented from rotating excessively around a direction normal to the scalp surface .
  • the electrodes of a given group are grouped into sub-groups or bundles which each contain the same number of electrodes or a similar number of electrodes with parallel lengths.
  • the electrodes are perpendicular to the surface on which they are lo- cated.
  • the electrodes can be arranged in a shape which has a circular, elliptical, triangular or rectangular outline.
  • the electrodes within a bundle can be arranged in concentrical circuits or some electrodes can be arranged around a center electrode. However, also other arrangements of the electrodes within a bundle are possible.
  • the electrodes can be arranged in bundle holding means which may be arranged at the group holding means through a joint which may be an elastic joint. If the electrodes are bundled the contact to the skin is ensured despite hair and surface irregularities . Each additional pin adds more potential contact surface between metal and skin, thus lowering the effective electrode impedance.
  • a group holding means can comprise two, three or more bundles of electrodes. If there are three bundles, those can be located at the corners of a triangle, preferably an equilateral triangle.
  • the group holding means can have a Y- structure, i.e. a structure with three straight legs which meet with one end at one point and preferably have the same length. The angles between the legs are preferably all equal.
  • An Y-shaped group holding means allows each branch of the Y to make contact with the scalp independently, as the spherical joint allows.
  • the relative stiffness among electrodes in a bundle is high, while the stiffness of the moving beam of the entire bundle's electrode arm is relatively low.
  • the bundles have three electrodes, those can also be placed at the corners of a triangle, which is preferably an equilateral triangle. The centre of this triangle marks the location of the bundle.
  • each single electrode is elasti- cally supported.
  • the electrodes can be guided in a guide member which guides the electrodes in the axial direction of their length, that is basically in the direction of the scalp.
  • the electrodes are supported on an elastic element which is elastic in the direction in which the electrodes can move in the guide.
  • the electrode is thus arranged like a piston in a cylinder.
  • the elastic element can be a spring which is placed inside the guide member behind the electrode in direction of the axial length of the electrode.
  • the electrodes can be virtually compressible, i.e. they are elastically deformable.
  • the electrodes can be thin metal pins .
  • the electrodes are coated or plated in a high conductance material, such as for example gold, platinum, silver, silver chloride other precious metals, alloys and/or conductive nanoparti- cles .
  • the electrodes are intended to measure electrical signals in an electroencephalography .
  • the electrodes can be wired in unipolar configuration in which all pins in a bundle are in contact with each other. A voltage can then be measured with reference to ground.
  • the electrodes can be arranged in a bipolar configuration where the electrodes of a bundle, a group or all electrodes are separated into two groups, wherein the electrodes of one group are electrically connected with each other and the electrodes of the other group are connected electrically with each other so that a voltage between the electrodes of the two groups can be measured.
  • Fig. 1 shows an electrode cap according to the present invention mounted on the head of a patient.
  • Fig. 2 shows a head strap with a holding arm which comprises a pivotal joint.
  • Fig. 3 shows a head strap with a holding arm which comprises a prismatic joint.
  • Fig. 4 shows a group holding means with three bundles of electrodes .
  • Fig. 5 shows a group holding means which is deform- able around an axis parallel to the length of the electrodes.
  • Fig. 6 shows an electrode cap mounted on the head of a patient viewed from above.
  • Fig. 7 shows three elastically supported electrodes.
  • Fig. 8 shows virtually compressible electrodes mounted on a group holding means .
  • Fig. 9 shows a unipolar configuration of an electrode bundle .
  • Fig. 10 shows a bipolar configuration of the electrodes in a bundle.
  • Fig. 1 shows an electrode cap according to the present invention mounted on the head 2 of a person.
  • the electrode cap comprises a head strap 1 which runs around the head 2.
  • the holding arms 3a and 3b each comprise two legs 4a and 5a as well as 4b and 5b which are connected with each other through revolute joints 6a, 6b.
  • the lower legs 4a and 4b which are supporting legs, are attached to the head strap 1 with one side and to the joints 6a and 6b, respectively, with the other side.
  • the second legs 5a and 5b which are electrode arm moving beams, carry group holding means 7a, 7b. Those have the form of 3 -branch-trees on which three bundles of electrodes are accommodated at the ends of its legs .
  • the electrode arm support 4a, 4b and the electrode arm moving beam 5a, 5b are each arranged at an angel which opens in the direction of the head. Between the two legs 4a and 5a as well as 4b and 5b, a flexing chord 8a, 8b is stretched. By these flexing chords 8a, 8b, the pressure by which the electrodes are pushed on the head 2 is adjustable.
  • Fig. 2 shows the electrode arm 3a in detail.
  • the electrode arm 3a is mounted on the head strap 1. It comprises a first leg 4a and a second leg 5a which are connected with each other through a pivotal joint 6a. Between the electrode arm support 4a and the electrode arm moving beam 5a, a flexing chord 8a is stretched which bends the electrode arm 3a around the joint 6a. The angle between the legs 4a and 5a is adjustable by changing the tension of the string 8a.
  • the flexing cord 8a may be elastic itself with an elastic stiffness K EAFC . The tension of the chord 8a can be adjusted by hand with the tightening screw 9.
  • Fig. 3 shows an alternative construction of the arm 3 which corresponds to the arms 3a and 3b in the previous figures.
  • the first leg 4a which is the electrode arm support, is connected with the second leg 5a via a prismatic joint 10.
  • the prismatic joint 10 is given by a drilling in the first arm 4a in which the second arm 5a is guided in the direction of its length.
  • the legs 4a and 5a build an angle which opens in the direction of the head.
  • the electrode arm support may have an angle, opening in the direction of the head.
  • the second arm 5a carries a group holding means 7 through a semi-rigid spherical joint 13.
  • the group holding means 7 carries the electrodes 12.
  • a spring 11 is located parallely to the second arm 5a, preferably surrounding the second arm 5a. This spring 11 therefore contracts or expands if a force is applied on the second arm 5a in the direction of its length. This happens for example when the electrodes 12 are pressed against the head of a patient .
  • Fig- 4 shows a group holding means carrying three bundles of electrodes 12.
  • Each bundle comprises three electrodes 12 which are located at the corners of an triangle, for example an equilateral triangle.
  • the upper part of the figure shows the view perpendicular to the length of the electrodes while the lower part of the figure shows a view from above.
  • the group holding means 7 has a Y-structure with three legs 14a, 41b, 14c of equal length which are arranged in equal angels to each other.
  • the holding structure 7 has a semi-rigid spherical joint 13 through which it is connected with the holding arm 3.
  • the semi-rigid spherical joint 13 is elastically mov- able around an axis 16 which is parallel to the electrodes 12 as well as one or two axises 15a and 15b which are perpendicular to the direction of the electrodes 12.
  • the torsional stiffness K ⁇ of the first axis is considerably greater than that of the second axis K 3 , in a similar manner as torques produced in response to motion by an elastic U-joint.
  • Fig. 5 shows an alternative construction of the group holding means 7.
  • the holding means 7 is fixed at a virtual ball joint 17.
  • a virtual ball joint is an elastic structure which, through its elasticity, provides the same motion as a ball joint on the distal end of an leg attached to the joint. Its response to deflections is equivalent to that of a spring- loaded ball joint.
  • the element 17 is bendable around at least one axis perpendicular to the electrodes 12 and may also be flexible around an axis parallel to the electrodes 12.
  • Fig. 6 shows an electrode cap according to the present invention viewed from above the head of the patient.
  • the shown configuration is a sample for BCI applications that utilize motor imagery.
  • the head strap 1 runs around the head of the patient and is closed with a closing means 18. This may allow the adjustment of the head strap 1.
  • the electrode arms 3a and 3b carry the group holding means 7a and 7b at which the electrodes 12 are arranged. In the shown example, the group holding means 7a and 7b have the
  • the configuration allows access to the central and lateral regions of the scalp and therefore the brain.
  • Fig. 7 shows electrodes which are elastically supported along their axis by means of moving parts and elastic elements.
  • the electrodes 12a, 12b and 12c are located in a holding means 7 and are each located in guide members 19a, 19b and 19c which only allow the electrodes to move in the direction of their axial length.
  • the electrodes are supported in contact with elastic elements, as for example springs 20a, 20b and 20c, which are fixed at the guiding means 19a, 19b, 19c with one end and are in contact with the electrodes 12a, 12b and 12c with the other end, respec- tively.
  • the electrodes 12a, 12b and 12c can therefore move in the cylindrical tubes 19a, 19b and 19c like a piston in a cylinder.
  • the example only shows three electrodes, however, any number of electrodes can be placed in a bundle, a group or the electrode cap.
  • Fig. 8 shows virtually compressible electrodes as an alternative for elastically supported electrodes .
  • the left part of Fig. 8 shows those electrodes 12a, 12b, 12c mounted on a holding means 7 if no force is ap- plied to the electrodes.
  • the right side of figure 8 shows the same setup if force is applied to the electrodes 12a to 12c.
  • the electrodes are elastical themselves, i.e. they bend elastically when a force is applied.
  • the electrodes can de- fleet in similar means as above by the flexibility of the shape and material from which they are made .
  • Figure 9 shows a unipolar configuration of electrodes in a bundle.
  • Six electrodes 12a to 12f are grouped around three electrodes 12g to 12i. All electrodes are electrically connected with each other and a voltage V u is measurable with reference to ground.
  • Figure 10 shows a bipolar configuration of electrodes in a bundle.
  • the electrodes are grouped into two parts, which form the two poles between which the voltage V b is measurable.
  • the electrodes 12a and 12b belong to one pole while the electrodes 12c and 12d belong to the other pole.
  • the electrodes of each part are electrically connected with each other.
  • the electrode cap according to the present invention is applicable wherever electroencephalography recordings are desirable with minimal preparation and long duration, that is duration longer than, e.g. two hours.
  • Those are for example medical diagnosis and monitoring, brain-computer-interfaces (BCI) , lie detection or monitoring of user attention in safety- critical operation of machines.
  • BCI brain-computer-interfaces
  • the electrode cap according to the present invention does not require conductive gel between the scalp and the electrodes and the force that each electrode pin exerts on the scalp is uniform and does not cause pain to the patient while the electrodes are in stable contact with the skin.
  • the overall level of force or the force ap- plied by certain groups of electrodes is adjustable.

Abstract

The invention relates to an electrode cap for electroencephalography which allows contacting the head of a human or an animal without a conductive gel between the scalp and the electrode itself. Claim 1 relates to an electrode cap for contacting the scalp of a head in an electro- encephalography with a number of pin-shaped electrodes (12) for contacting the scalp, and an electrode holding means characterized in that the electrodes are mounted on the electrode holding means through at least one elastic ( 8, 11, 13, 17, 20) joint.

Description

Dry electrode cap for electro-encephalography
The invention relates to an electrode cap for electro-encephalography which allows contacting the head of a human or an animal without a conductive gel between the scalp and the electrode itself.
The most common non-invasive solution to collect electro-encephalography (EEG) data, applied in bio- medical research and hospitals, is the wet electrode, comprising a metal plate coated with Ag. This wet electrode requires gel to be applied between the skin and the electrode to allow for the exchange of ions at the interface. The use of such a gel is inconven- ient for a daily use of the electrodes: it requires a time consuming preparation before any EEG recording can be carried out; the gel dries with the passing of time and thus needs to be refilled in long applications of the electrodes to the scalp. It has also been reported that long term contact with the skin produces irritation.
An alternative approach to the collection of EEG data is the use of sensors that operate with current dis- placement, that is a capacitive transduction, instead of charge current, as was the case for the previous example . These types of electrodes do not require physical contact to the signal source. However, the advantage of independence of contact with the body brings along the disadvantage that the background noise recorded along with the physiological signals is higher.
All other solutions make contact with the skin. Some make use of NASICON ceramic material. The particular propriety of interest of the NASICON (acronym for Na Super Ionic Conductor) material is its very high conductivity of Na+ ions even at room temperature. The downside of using this material is a higher impedance mismatch with the skin than the common wet electrodes .
Microfabrication technology has produced good results in miniaturization of real size sensors. As interest- ing examples, Griss et al . developed a dry electrode that avoids the use of electrolytic gel and at the same time fixes the electrode to the skull surface with enough reliability to avoid motion artifacts, making use of microfabricated spikes on the electrode surface (Griss, P et al . , "Characterization of micro- machined spiked biopotential electrodes" , Biomedical Engineering, IEEE Transactions on Volume 49, Issue: 6 June 2002) .
There is a higher potential difference measured between a pair of such electrodes than in the case of the standard wet electrodes which could be due to the influence of the potential of the sweating duct membranes in the dermis. Despite this fact, it seems that sweat on the skin does not produce so much variation on the electrode impedance as occurs with
Ag/AgCl electrodes . The spikes prickle the outer layers of the skin but avoid penetrating the dermis, where nerves and blood vessels are. This way, pain- free measurements of potentials is achieved, avoiding the high impedance from the outer skin layers.
Another solution makes use of carbon nanotubes. In a similar configuration, a population of carbon nanotubes are used as probes that, in pricking the sur- face layers of the dermis, behave as the transducers themselves .
It is therefore the problem to be solved by the present invention to provide an easily manufacturable, affordable device which can be placed on the head in a few minutes, is comfortable, makes reliable long- term skin contact without pain, and provides enough accuracy in recording of brain activity for applications such as for example brain-computer interfaces.
This problem is solved by the electrode cap according to claim 1, the contacting method according to claim 29 and the use of the electrode cap according to claim 28. Advantageous embodiments of the electrode cap and the method are given by the respective dependent claims.
The present invention is based on the idea that an optimal result of an electroencephalography measure- ment (EEG) together with a maximum of wearing comfort for the patient is achieved if the force that each pin exerts on the scalp of the patient is uniform for all electrodes or groups of electrodes and can be adjusted.
According to the present invention, this is achieved by mounting or supporting the electrodes on an electrode holding means through at least one elastic joint. The electrodes push down onto the surface of the scalp by means of an elastic force, as for exam- pie that of a spring or of pneumatic pressure.
The electrode holding means preferably comprises a head- fixing means, such as for example an adjustable head strap which tightens around the forehead, side and back of the head and allows to fix the electrode cap to the head with adjustable pressure.
Preferably, the electrodes are mounted on the electrode holding means through one or more connecting means which preferably are or comprise a small number, for example 2 to 30, holding arms. As many arms can be used as can be fit without interfering with each other physically. Those holding arms are fixed to the head fixing means or head strap with one end while the other end carries the electrodes. The electrodes can be attached to the holding arms directly or indirectly through other components.
It is preferred that the holding arms comprise two legs which are connected with each other through an elastic joint. The lower part of the arm, that is the leg which is connected to the head fixing means, is called electrode arm support. To this an electrode arm moving beam, that is the leg which carries the electrodes, is attached by means of a revolute or prismatic joint. Preferably, this allows the distal end of the arm to move perpendicularly to the surface of the scalp. If the legs of the arms are straight they preferably include an angle which opens in the direction of the head. The elastic joint between the legs of an arm can be a revolute joint or a pivotal joint of which the rotation axis is perpendicular to the length of the legs and tangential to the head.
It is preferred that a torque-producing flexing cord or a similarly adjustable torsional spring is stretched between pairs of adjacent legs of an arm which are connected with each other by an elastic joint. This allows to apply a bending moment around this elastic joint which connects the two legs. By adjusting the length of such a cord or spring, the pressure which the electrodes apply to the scalp of the head can be adjusted. The cord or spring may have a certain elastic stiffness KEAFC and zero point XOEAFC either of which may be adjustable by hand via a tightening screw or a geared mechanism.
It is also possible that the joint between two adjacent legs is a prismatic joint which is preferably movable in the direction of the head of the patient . Such a prismatic joint comprises a bore or cylinder in one leg in which a part of the other leg is guided in one direction, for example the direction of the length of the leg.
Between the two legs, a spring or some other flexible element can be arranged, which expands or contracts if the legs are moved against each other. It is furthermore possible to connect two neighbouring legs of an arm by a flexing chord, similarly as outlined for the pivotal joint, above. By this a force is applicable in the direction in which the prismatic joint is movable . This force can act in the direction of the elastic force of the elastic element or in the opposite direction. By adjusting the length of such a cord, the pressure which the electrodes apply to the scalp of the head can be adjusted. This cord also may have a certain elastic stiffness KEAFC and zero point XoEAFc either of which may be adjustable by hand via a tightening screw or a geared mechanism.
Preferably, the individual electrodes are grouped into groups whereby each group comprises a part of the electrodes . The number of electrodes in each group is preferably equal but can also be different.
Electrodes which belong to the same group are held by a common group holding means which holds all electrodes of this group. The group holding means are each mounted directly or indirectly on the electrode holding means through at least one elastic joint. As explained above this holding means can be an electrode holding arm wherein the different legs are connected through elastic joints.
The group holding means preferably comprise at least one elastic joint through which they are mounted on the electrode holding means or the holding arm. Such an elastic joint can be a semi-rigid spherical joint or a virtual ball joint which is an elastic structure which, through its elasticity, provides the same mo- tion as a ball joint on the distal end of a leg attached to the joint. Its response to deflections is equivalent to that of a spring-loaded ball joint. Such a joint can be movable around a first axis parallel to the length of the electrodes, i.e. parallel to the direction of the force by which the electrodes are pressed against the head. For this direction, the joint then has a certain torsional stiffness K3. It is furthermore possible that the joint is movable around at least one axis perpendicular to the direction in which the force acts which applies pressure to the head. In this direction, the joint has a torsional stiffness Kτ. If the joint is movable around an axis perpendicular to the length of the electrodes, the surface which is described by the tips of the electrodes can adjust its orientation to the slope of the head at the position where the electrodes are applied. It is preferred that the torsional stiffness around the axis perpendicular to the length of the electrodes Kτ is considerably greater than the torsional stiffness K3 around the axis par- allel to the length of the electrodes. By this, the group holding means can be prevented from rotating excessively around a direction normal to the scalp surface .
Preferably, the electrodes of a given group are grouped into sub-groups or bundles which each contain the same number of electrodes or a similar number of electrodes with parallel lengths. The electrodes are perpendicular to the surface on which they are lo- cated. There may exist two, three or more bundles of electrodes in one group. Within a bundle, the electrodes can be arranged in a shape which has a circular, elliptical, triangular or rectangular outline. The electrodes within a bundle can be arranged in concentrical circuits or some electrodes can be arranged around a center electrode. However, also other arrangements of the electrodes within a bundle are possible. If necessary, the electrodes can be arranged in bundle holding means which may be arranged at the group holding means through a joint which may be an elastic joint. If the electrodes are bundled the contact to the skin is ensured despite hair and surface irregularities . Each additional pin adds more potential contact surface between metal and skin, thus lowering the effective electrode impedance.
A group holding means can comprise two, three or more bundles of electrodes. If there are three bundles, those can be located at the corners of a triangle, preferably an equilateral triangle. In this configu- ration, the group holding means can have a Y- structure, i.e. a structure with three straight legs which meet with one end at one point and preferably have the same length. The angles between the legs are preferably all equal. An Y-shaped group holding means allows each branch of the Y to make contact with the scalp independently, as the spherical joint allows.
The relative stiffness among electrodes in a bundle is high, while the stiffness of the moving beam of the entire bundle's electrode arm is relatively low.
If the bundles have three electrodes, those can also be placed at the corners of a triangle, which is preferably an equilateral triangle. The centre of this triangle marks the location of the bundle.
It is preferred that each single electrode is elasti- cally supported. Hereby, the electrodes can be guided in a guide member which guides the electrodes in the axial direction of their length, that is basically in the direction of the scalp. Within the guides the electrodes are supported on an elastic element which is elastic in the direction in which the electrodes can move in the guide. The electrode is thus arranged like a piston in a cylinder. The elastic element can be a spring which is placed inside the guide member behind the electrode in direction of the axial length of the electrode.
Alternatively, the electrodes can be virtually compressible, i.e. they are elastically deformable. Here the electrodes can be thin metal pins .
It is preferred that the electrodes are coated or plated in a high conductance material, such as for example gold, platinum, silver, silver chloride other precious metals, alloys and/or conductive nanoparti- cles .
The electrodes are intended to measure electrical signals in an electroencephalography . For this purpose, the electrodes can be wired in unipolar configuration in which all pins in a bundle are in contact with each other. A voltage can then be measured with reference to ground. Alternatively, the electrodes can be arranged in a bipolar configuration where the electrodes of a bundle, a group or all electrodes are separated into two groups, wherein the electrodes of one group are electrically connected with each other and the electrodes of the other group are connected electrically with each other so that a voltage between the electrodes of the two groups can be measured.
Brief description of the figures
Fig. 1 shows an electrode cap according to the present invention mounted on the head of a patient.
Fig. 2 shows a head strap with a holding arm which comprises a pivotal joint. Fig. 3 shows a head strap with a holding arm which comprises a prismatic joint.
Fig. 4 shows a group holding means with three bundles of electrodes .
Fig. 5 shows a group holding means which is deform- able around an axis parallel to the length of the electrodes.
Fig. 6 shows an electrode cap mounted on the head of a patient viewed from above.
Fig. 7 shows three elastically supported electrodes.
Fig. 8 shows virtually compressible electrodes mounted on a group holding means .
Fig. 9 shows a unipolar configuration of an electrode bundle .
Fig. 10 shows a bipolar configuration of the electrodes in a bundle.
Detailed description of the drawings
Fig. 1 shows an electrode cap according to the present invention mounted on the head 2 of a person. The electrode cap comprises a head strap 1 which runs around the head 2. On opposite sides of the head strap 1, two holding arms 3a and 3b are attached. The holding arms 3a and 3b each comprise two legs 4a and 5a as well as 4b and 5b which are connected with each other through revolute joints 6a, 6b. The lower legs 4a and 4b, which are supporting legs, are attached to the head strap 1 with one side and to the joints 6a and 6b, respectively, with the other side. The second legs 5a and 5b, which are electrode arm moving beams, carry group holding means 7a, 7b. Those have the form of 3 -branch-trees on which three bundles of electrodes are accommodated at the ends of its legs .
The electrode arm support 4a, 4b and the electrode arm moving beam 5a, 5b are each arranged at an angel which opens in the direction of the head. Between the two legs 4a and 5a as well as 4b and 5b, a flexing chord 8a, 8b is stretched. By these flexing chords 8a, 8b, the pressure by which the electrodes are pushed on the head 2 is adjustable.
Fig. 2 shows the electrode arm 3a in detail. The electrode arm 3a is mounted on the head strap 1. It comprises a first leg 4a and a second leg 5a which are connected with each other through a pivotal joint 6a. Between the electrode arm support 4a and the electrode arm moving beam 5a, a flexing chord 8a is stretched which bends the electrode arm 3a around the joint 6a. The angle between the legs 4a and 5a is adjustable by changing the tension of the string 8a. The flexing cord 8a may be elastic itself with an elastic stiffness KEAFC. The tension of the chord 8a can be adjusted by hand with the tightening screw 9.
Fig. 3 shows an alternative construction of the arm 3 which corresponds to the arms 3a and 3b in the previous figures. The first leg 4a, which is the electrode arm support, is connected with the second leg 5a via a prismatic joint 10. The prismatic joint 10 is given by a drilling in the first arm 4a in which the second arm 5a is guided in the direction of its length.
Again, the legs 4a and 5a build an angle which opens in the direction of the head. Also the electrode arm support may have an angle, opening in the direction of the head. The second arm 5a carries a group holding means 7 through a semi-rigid spherical joint 13. The group holding means 7 carries the electrodes 12. Between the group holding means 7 and the first arm 4a, a spring 11 is located parallely to the second arm 5a, preferably surrounding the second arm 5a. This spring 11 therefore contracts or expands if a force is applied on the second arm 5a in the direction of its length. This happens for example when the electrodes 12 are pressed against the head of a patient .
Fig- 4 shows a group holding means carrying three bundles of electrodes 12. Each bundle comprises three electrodes 12 which are located at the corners of an triangle, for example an equilateral triangle. The upper part of the figure shows the view perpendicular to the length of the electrodes while the lower part of the figure shows a view from above. It can be seen from the lower part of the figure, that the group holding means 7 has a Y-structure with three legs 14a, 41b, 14c of equal length which are arranged in equal angels to each other. The holding structure 7 has a semi-rigid spherical joint 13 through which it is connected with the holding arm 3.
The semi-rigid spherical joint 13 is elastically mov- able around an axis 16 which is parallel to the electrodes 12 as well as one or two axises 15a and 15b which are perpendicular to the direction of the electrodes 12. The torsional stiffness Kτ of the first axis is considerably greater than that of the second axis K3, in a similar manner as torques produced in response to motion by an elastic U-joint. Fig. 5 shows an alternative construction of the group holding means 7. Here, the holding means 7 is fixed at a virtual ball joint 17. A virtual ball joint is an elastic structure which, through its elasticity, provides the same motion as a ball joint on the distal end of an leg attached to the joint. Its response to deflections is equivalent to that of a spring- loaded ball joint.
The element 17 is bendable around at least one axis perpendicular to the electrodes 12 and may also be flexible around an axis parallel to the electrodes 12.
Fig. 6 shows an electrode cap according to the present invention viewed from above the head of the patient. The shown configuration is a sample for BCI applications that utilize motor imagery. The head strap 1 runs around the head of the patient and is closed with a closing means 18. This may allow the adjustment of the head strap 1. The electrode arms 3a and 3b carry the group holding means 7a and 7b at which the electrodes 12 are arranged. In the shown example, the group holding means 7a and 7b have the
Y-structure as described above. The configuration allows access to the central and lateral regions of the scalp and therefore the brain.
Fig. 7 shows electrodes which are elastically supported along their axis by means of moving parts and elastic elements. The electrodes 12a, 12b and 12c are located in a holding means 7 and are each located in guide members 19a, 19b and 19c which only allow the electrodes to move in the direction of their axial length. The electrodes are supported in contact with elastic elements, as for example springs 20a, 20b and 20c, which are fixed at the guiding means 19a, 19b, 19c with one end and are in contact with the electrodes 12a, 12b and 12c with the other end, respec- tively. The electrodes 12a, 12b and 12c can therefore move in the cylindrical tubes 19a, 19b and 19c like a piston in a cylinder. The example only shows three electrodes, however, any number of electrodes can be placed in a bundle, a group or the electrode cap.
Fig. 8 shows virtually compressible electrodes as an alternative for elastically supported electrodes . The left part of Fig. 8 shows those electrodes 12a, 12b, 12c mounted on a holding means 7 if no force is ap- plied to the electrodes. The right side of figure 8 shows the same setup if force is applied to the electrodes 12a to 12c. Here, the electrodes are elastical themselves, i.e. they bend elastically when a force is applied. In other words, the electrodes can de- fleet in similar means as above by the flexibility of the shape and material from which they are made .
Figure 9 shows a unipolar configuration of electrodes in a bundle. Six electrodes 12a to 12f are grouped around three electrodes 12g to 12i. All electrodes are electrically connected with each other and a voltage Vu is measurable with reference to ground.
Figure 10 shows a bipolar configuration of electrodes in a bundle. The electrodes are grouped into two parts, which form the two poles between which the voltage Vb is measurable. The electrodes 12a and 12b belong to one pole while the electrodes 12c and 12d belong to the other pole. The electrodes of each part are electrically connected with each other. The electrode cap according to the present invention is applicable wherever electroencephalography recordings are desirable with minimal preparation and long duration, that is duration longer than, e.g. two hours. Those are for example medical diagnosis and monitoring, brain-computer-interfaces (BCI) , lie detection or monitoring of user attention in safety- critical operation of machines. The electrode cap according to the present invention does not require conductive gel between the scalp and the electrodes and the force that each electrode pin exerts on the scalp is uniform and does not cause pain to the patient while the electrodes are in stable contact with the skin. The overall level of force or the force ap- plied by certain groups of electrodes is adjustable.

Claims

Claims
1. Electrode cap for contacting the scalp of a head in an electroencephalography with a number of pin-shaped electrodes for contacting the scalp, and an electrode holding means c h a r a c t e r i z e d i n t h a t the electrodes are mounted on the electrode- holding means through at least one elastic joint.
2. The electrode cap according to the preceding claim, characterized in that the electrodes are mounted on the electrode holding means through at least one connecting means .
3. The electrode cap according to one of the preceding claims, characterized in that the electrodes are grouped into one or more groups, wherein the electrodes of each group are mounted on a common group-holding means and wherein the group-holding means are each mounted on the electrode-holding means through at least one elastic joint.
4. The electrode cap according to one of the preceding claims, characterized in that the electrode-holding means comprises a head- fixing means for fixing the electrode cap to the head.
5. The electrode cap according to the preceding claim, characterized in that the head-fixing means comprises a head strap.
6. The electrode cap according to one of claims 2 to 5, characterized in that the connecting means comprises at least one holding arm of which one end is fixed to the head- fixing means and the other end directly or indirectly carries at least some of the electrodes or at least one group of electrodes.
7. The electrode cap according to the preceding claim, characterized in that the at least one holding arm comprises at least two legs which are connected with each other in a row through one of the at least one elastic joints , and that a first leg, which is connected to only one other leg, is fixed to the head- fixing means at its end distal to the elastic joint by which it is connected to the other leg, and that a second leg, which is connected to only one other leg, carries at least some of the electrodes or at least one group of electrodes.
8. The electrode cap according to the preceding claim, characterized in that the at least two legs are connected with each other at an angle opening in the direction of the head.
9. The electrode cap according to one of the two preceding claims, characterized in that the elastic joint is a revolute joint or pivotal joint of which the rotation axis is perpendicular to the length of the legs and tangential to the head.
10. The electrode cap according to one of claims 7 to 9, characterized by at least one flexing cord and/or torsional spring which connects two adja- cent legs of the at least one holding arm which are connected with each other by a joint, and by which a bending moment around the elastic joint which connects the two adjacent legs is applicable.
11. The electrode cap according to one of claims 7 to 10, characterized in that at least one of the at least one elastic joints is a prismatic joint which is movable in the direction of the head.
12. The electrode cap according to the preceding claim, characterized by at least one flexible element or spring which connects two adjacent legs of the at least one holding arm which are connected with each other through a prismatic joint, and which contracts or expands in the direction in which the prismatic joint is movable.
13. The electrode cap according to one of the two preceding claims, characterized by at least one flexing cord which connects two adjacent legs of the at least one holding arm which are connected with each other through a prismatic joint and by which a force in the direction in which the prismatic joint is movable is applicable.
14. The electrode cap according to one of claims 3 to 13, characterized in that the group-holding means comprise at least one second elastic joint through which they are mounted on the electrode-holding means or con- necting means.
15. The electrode cap according to the preceding claim, characterized in that the second elastic joint is a semi-rigid spheri- cal joint or a virtual ball joint which is movable around a first axis parallel to the length of the electrodes of this group with a torsional stiffness K3 and/or around at least one axis perpendicular to the length of the electrodes with a torsional stiffness of Kτ.
16. The electrode cap according to the preceding claim, characterized in that Kτ is greater than Ks.
17. The electrode cap according to one of claims 3 to 16, characterized in that the electrodes of at least one group are grouped into at least two bundles .
18. The electrode cap according to one of claims 3 to 17, characterized in that the electrodes of a group are grouped into three bundles which are located at the corners of a triangle.
19. The electrode cap according to the preceding claim, characterized in that the group-holding means has a Y-structure, whereby the three bundles are located at the ends of the legs of the Y-structure.
20. The electrode cap according to claim 17 to 19, characterized in that each bundle has three electrodes which are located at the corners of a triangle .
21. The electrode cap according to one of the preceding claims, characterized in that at least one electrode or the majority of electrodes in one bundle, one group or all electrodes respectively are separately guided in a guide member, guiding the electrodes in the axial direction of their lengths, and supported on an elastic element which is elastic in the direction of these lengths.
22. The electrode cap according to the preceding claim, characterized in that the elastic element is a spring of which one end is fixed at the electrode-holding means and the other end is in contact with the electrodes .
23. The electrode cap according to one of the preceding claims, characterized in that the electrodes are elastically supported through movable parts and/or springs and/or that the electrodes are virtually compressible.
24. The electrode cap according to one of the preceding claims, characterized in that all electrodes or all electrodes of at least one group or all electrodes of at least one bundle are electrically connected with each other.
25. The electrode cap according to one of claims 1 to 23, characterized in that the electrodes or the electrodes of each group or the electrodes of each bundle are grouped into two parts, wherein the electrodes of each part are electrically connected with each other and wherein a voltage is applicable between the two parts.
26. The electrode cap according to one of the preceding claims, characterized in that the electrodes are coated or plated in a high- conductance material .
27. The electrode cap according to one of the preceding claims, characterized in that the electrodes are coated or plated in gold, platinum, silver, silver chloride, precious met- als, alloys or conductive nanoparticles .
28. Use of an electrode cap according to one of the preceding claims for electroencephalography.
29. Method for contacting the scalp of a head in an electroencephalography, wherein the scalp is contacted by an electrode cap comprising a number of pin-shaped electrodes which are mounted on an electrode holding means through at least one elastic joint.
30. Method according to the preceding claim, charac- terized in that the electrode cap is an electrode cap according to one of claims 1 to 27.
PCT/EP2006/011843 2006-12-08 2006-12-08 Dry electrode cap for electro-encephalography WO2008067839A1 (en)

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PCT/EP2006/011843 WO2008067839A1 (en) 2006-12-08 2006-12-08 Dry electrode cap for electro-encephalography
EP06840965.5A EP2101640B1 (en) 2006-12-08 2006-12-08 Dry electrode cap for electro-encephalography
US12/517,664 US8548554B2 (en) 2006-12-08 2006-12-08 Dry electrode cap for electro-encephalography
ES06840965T ES2409734T3 (en) 2006-12-08 2006-12-08 Dry electrode cap for electroencephalography
JP2009539609A JP5367579B2 (en) 2006-12-08 2006-12-08 Dry electrode cap for EEG measurement

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EP (1) EP2101640B1 (en)
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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009134763A1 (en) * 2008-04-29 2009-11-05 Board of Governors for Higher Education, State of Rhode Island and the Providence Plantations Biomedical sensors usable on un-prepared contact surfaces
WO2011055291A1 (en) * 2009-11-04 2011-05-12 Koninklijke Philips Electronics N.V. Device for positioning electrodes on a user's scalp
EP2341824A1 (en) * 2008-09-12 2011-07-13 Neurosky, Inc. Contoured electrode
DE102010005551A1 (en) 2010-01-22 2011-07-28 Badower, Yakob, Dipl.-Ing. Sensor system for non-invasive detection of e.g. electrocardiogram signals of biological elements in head of human, has body contact electrodes coupled to shielding device for providing interference signals to shielding device
DE102010017415A1 (en) 2010-06-17 2011-12-22 Yakob Badower Sensor system i.e. head sensor system, for non-invasive detecting e.g. ECG signals of biological origin mounted on head of human body, has measuring electrodes partly formed of thermoplastic elastomer
US8103328B2 (en) * 2007-10-01 2012-01-24 Quantum Applied Science And Research, Inc. Self-locating sensor mounting apparatus
CN102579041A (en) * 2012-02-09 2012-07-18 上海交通大学 Arrayed flexible electroencephalogram dry electrode capable of overcoming obstacle of hair and preparation method thereof
US8326396B2 (en) 2010-03-24 2012-12-04 Brain Products Gmbh Dry electrode for detecting EEG signals and attaching device for holding the dry electrode
JP2013166005A (en) * 2009-11-10 2013-08-29 Japan Health Science Foundation Brain wave measuring electrode, cap with brain wave measuring electrode and brain wave measuring device
WO2015062561A1 (en) * 2013-10-30 2015-05-07 Univerzita Karlova V Praze Lekarska Fakulta V Hradci Kralove Dry electrode for registration of biopotentials from the scalp of a head
WO2016016526A1 (en) * 2014-07-30 2016-02-04 Jean-Tien Equipment for applying active elements to the skull of a patient
JP2018068436A (en) * 2016-10-25 2018-05-10 株式会社タニタ Living body measurement device
WO2019018321A1 (en) 2017-07-18 2019-01-24 Forest Devices, Inc. Electrode array apparatus, neurological condition detection apparatus, and method of using the same

Families Citing this family (73)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090024049A1 (en) 2007-03-29 2009-01-22 Neurofocus, Inc. Cross-modality synthesis of central nervous system, autonomic nervous system, and effector data
WO2008137579A1 (en) 2007-05-01 2008-11-13 Neurofocus, Inc. Neuro-informatics repository system
WO2008137581A1 (en) 2007-05-01 2008-11-13 Neurofocus, Inc. Neuro-feedback based stimulus compression device
US8392253B2 (en) 2007-05-16 2013-03-05 The Nielsen Company (Us), Llc Neuro-physiology and neuro-behavioral based stimulus targeting system
WO2008153713A1 (en) * 2007-05-23 2008-12-18 Quantum Applied Science And Research, Inc. Sensor mounting system
US8494905B2 (en) 2007-06-06 2013-07-23 The Nielsen Company (Us), Llc Audience response analysis using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI)
JP5542051B2 (en) 2007-07-30 2014-07-09 ニューロフォーカス・インコーポレーテッド System, method, and apparatus for performing neural response stimulation and stimulation attribute resonance estimation
US8635105B2 (en) 2007-08-28 2014-01-21 The Nielsen Company (Us), Llc Consumer experience portrayal effectiveness assessment system
US8386313B2 (en) 2007-08-28 2013-02-26 The Nielsen Company (Us), Llc Stimulus placement system using subject neuro-response measurements
US8392254B2 (en) 2007-08-28 2013-03-05 The Nielsen Company (Us), Llc Consumer experience assessment system
US8392255B2 (en) 2007-08-29 2013-03-05 The Nielsen Company (Us), Llc Content based selection and meta tagging of advertisement breaks
US8494610B2 (en) 2007-09-20 2013-07-23 The Nielsen Company (Us), Llc Analysis of marketing and entertainment effectiveness using magnetoencephalography
US20090083129A1 (en) * 2007-09-20 2009-03-26 Neurofocus, Inc. Personalized content delivery using neuro-response priming data
US11672483B2 (en) * 2008-02-04 2023-06-13 University of Pittsburgh—of the Commonwealth System of Higher Education Skin screw electrodes
US9357240B2 (en) 2009-01-21 2016-05-31 The Nielsen Company (Us), Llc Methods and apparatus for providing alternate media for video decoders
US8270814B2 (en) 2009-01-21 2012-09-18 The Nielsen Company (Us), Llc Methods and apparatus for providing video with embedded media
US8464288B2 (en) 2009-01-21 2013-06-11 The Nielsen Company (Us), Llc Methods and apparatus for providing personalized media in video
US20100250325A1 (en) 2009-03-24 2010-09-30 Neurofocus, Inc. Neurological profiles for market matching and stimulus presentation
JP5589593B2 (en) * 2009-06-29 2014-09-17 ソニー株式会社 Biological signal measuring device
US20110015536A1 (en) * 2009-07-17 2011-01-20 Michael Milgramm EEG-based method for determining a subject's compatibility with a work environment
US8655437B2 (en) 2009-08-21 2014-02-18 The Nielsen Company (Us), Llc Analysis of the mirror neuron system for evaluation of stimulus
US10987015B2 (en) 2009-08-24 2021-04-27 Nielsen Consumer Llc Dry electrodes for electroencephalography
US9560984B2 (en) 2009-10-29 2017-02-07 The Nielsen Company (Us), Llc Analysis of controlled and automatic attention for introduction of stimulus material
US8209224B2 (en) 2009-10-29 2012-06-26 The Nielsen Company (Us), Llc Intracluster content management using neuro-response priming data
US20110106750A1 (en) 2009-10-29 2011-05-05 Neurofocus, Inc. Generating ratings predictions using neuro-response data
US8335715B2 (en) 2009-11-19 2012-12-18 The Nielsen Company (Us), Llc. Advertisement exchange using neuro-response data
US8335716B2 (en) 2009-11-19 2012-12-18 The Nielsen Company (Us), Llc. Multimedia advertisement exchange
KR100965351B1 (en) * 2009-11-23 2010-06-22 박문서 Apparatus for acupuncturing with measuring impedance in humanbody using electrode apparatus for measuring impedance in humanbody
WO2011133548A2 (en) 2010-04-19 2011-10-27 Innerscope Research, Inc. Short imagery task (sit) research method
US8655428B2 (en) 2010-05-12 2014-02-18 The Nielsen Company (Us), Llc Neuro-response data synchronization
JP5516137B2 (en) * 2010-06-28 2014-06-11 ソニー株式会社 Biological signal detection electrode and biological signal detection device
US8392251B2 (en) 2010-08-09 2013-03-05 The Nielsen Company (Us), Llc Location aware presentation of stimulus material
US8392250B2 (en) 2010-08-09 2013-03-05 The Nielsen Company (Us), Llc Neuro-response evaluated stimulus in virtual reality environments
US8396744B2 (en) 2010-08-25 2013-03-12 The Nielsen Company (Us), Llc Effective virtual reality environments for presentation of marketing materials
WO2013155280A1 (en) * 2010-11-15 2013-10-17 Heck Sandy L Electrodes adapted for transmitting or measuring voltages through hair
AT511239B1 (en) * 2011-03-21 2014-12-15 Christoph Dipl Ing Dr Techn Guger DEVICE FOR CREATING ELECTRODE ARRANGEMENTS
US9292858B2 (en) 2012-02-27 2016-03-22 The Nielsen Company (Us), Llc Data collection system for aggregating biologically based measures in asynchronous geographically distributed public environments
US9451303B2 (en) 2012-02-27 2016-09-20 The Nielsen Company (Us), Llc Method and system for gathering and computing an audience's neurologically-based reactions in a distributed framework involving remote storage and computing
US9569986B2 (en) 2012-02-27 2017-02-14 The Nielsen Company (Us), Llc System and method for gathering and analyzing biometric user feedback for use in social media and advertising applications
CN104470424B (en) * 2012-03-19 2017-09-08 科尼翁尼克斯公司 Converter assembly for the dry applications of converter
US11850052B2 (en) * 2014-01-28 2023-12-26 Medibotics Llc Dry EEG electrode for use on a hair-covered portion of a person's head
US9060703B2 (en) * 2012-07-18 2015-06-23 Neurotopia, Inc. Neurophysiological dry sensor
US8989835B2 (en) 2012-08-17 2015-03-24 The Nielsen Company (Us), Llc Systems and methods to gather and analyze electroencephalographic data
TWI568412B (en) * 2012-08-23 2017-02-01 國立交通大學 A sensor electrode for measuring bio-medical signals and its fabricating method thereof
KR101407967B1 (en) * 2012-09-10 2014-06-19 전자부품연구원 Electrode Assembly for Electrocorticography with Height and Direction Variable Electrode and Apparatus for Electrocorticography using the same
WO2014130571A1 (en) 2013-02-19 2014-08-28 The Regents Of The University Of California Methods of decoding speech from the brain and systems for practicing the same
US10893821B2 (en) 2013-03-14 2021-01-19 Encephalodynamics, Inc. Electrode assemblies and electroencephalographic devices, methods and kits
US9320450B2 (en) 2013-03-14 2016-04-26 The Nielsen Company (Us), Llc Methods and apparatus to gather and analyze electroencephalographic data
TWI547263B (en) * 2013-03-22 2016-09-01 國立交通大學 Line-junction dry electrode
US20150238100A1 (en) * 2014-02-27 2015-08-27 National Chiao Tung University Sensor electrode device
US9398864B2 (en) 2014-03-12 2016-07-26 The Nielsen Company (Us), Llc Methods and apparatus to gather and analyze electroencephalographic data
US9622702B2 (en) 2014-04-03 2017-04-18 The Nielsen Company (Us), Llc Methods and apparatus to gather and analyze electroencephalographic data
JP2016010482A (en) * 2014-06-27 2016-01-21 パナソニックIpマネジメント株式会社 Optical hair growth device
WO2016080804A1 (en) * 2014-11-20 2016-05-26 Samsung Electronics Co., Ltd. Apparatus for measuring bioelectrical signals
US20160157777A1 (en) 2014-12-08 2016-06-09 Mybrain Technologies Headset for bio-signals acquisition
EP3033994A1 (en) * 2014-12-17 2016-06-22 Stichting IMEC Nederland Electrode for biopotential sensing
USD747495S1 (en) 2014-12-29 2016-01-12 Mybrain Technologies Headset for bio-signals acquisition
US9936250B2 (en) 2015-05-19 2018-04-03 The Nielsen Company (Us), Llc Methods and apparatus to adjust content presented to an individual
TWI552721B (en) * 2015-10-21 2016-10-11 國立交通大學 Bio-signal sensor
USD809474S1 (en) * 2015-12-30 2018-02-06 Mybrain Technologies Audio headset for bio-signals acquisition
KR101780437B1 (en) * 2015-12-31 2017-09-21 고려대학교 산학협력단 Electrode for hairy animal and a method thereof
US10568572B2 (en) * 2016-03-14 2020-02-25 The Nielsen Company (Us), Llc Headsets and electrodes for gathering electroencephalographic data
EP3241494A1 (en) * 2016-05-04 2017-11-08 Valtronic Technologies (Holding) SA Device for detecting or monitoring bioelectrical parameters
US11759147B2 (en) 2016-06-08 2023-09-19 The Trustees Of Columbia University In The City Of New York Systems and methods for real-time concussion diagnosis by electroencephalogram activity monitoring
JP7000678B2 (en) * 2016-12-13 2022-01-19 凸版印刷株式会社 EEG electrode holder
JP6927632B2 (en) * 2017-04-11 2021-09-01 ニッタ株式会社 Electrodes for EEG measurement
RU177707U1 (en) * 2017-05-25 2018-03-06 Общество С Ограниченной Ответственностью Инженерный Центр "Комплекс-М" DEVICE FOR REGISTRATION OF ELECTROENCEPHALOGRAPHIC SIGNALS
EP3629912A4 (en) * 2017-05-30 2021-03-03 InteraXon Inc. Wearable computing device with electrophysiological sensors
WO2019068817A1 (en) 2017-10-05 2019-04-11 Innovative Molecules Gmbh Enantiomers of substituted thiazoles as antiviral compounds
CN117257315A (en) 2017-12-01 2023-12-22 泽图有限公司 Head-mounted assembly and electrode for sensing biopotential and method of operating the same
EP3958733A4 (en) 2019-04-22 2022-12-21 The Regents of the University of California Methods of generating speech using articulatory physiology and systems for practicing the same
CN111358442A (en) * 2020-04-14 2020-07-03 青岛柏恩鸿泰电子科技有限公司 Multi-guide sleep monitoring cap
GB2613869A (en) * 2021-12-17 2023-06-21 Kouo Ltd Sensing apparatus and method of manufacture

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB818711A (en) * 1955-12-06 1959-08-19 Mini Of Supply Stereotaxic device
GB1322472A (en) 1971-11-09 1973-07-04 Humetrics Corp Head harness for eeg electrodes
US4084583A (en) * 1975-04-24 1978-04-18 Siemens Aktiengesellschaft Method and apparatus for measuring the bioelectrical activity under an electrode resting on a patient
US4350164A (en) * 1980-06-03 1982-09-21 Allain Jr Joseph L Portable, life monitor, medical instrument
EP0232102A2 (en) * 1986-01-27 1987-08-12 Westinghouse Electric Corporation An electroencephalographic head set with disposable electrodes and disposable electrolyte applicator
US4928696A (en) * 1989-07-26 1990-05-29 Mindcenter Corporation Electrode-supporting headset
EP0541393A1 (en) 1991-11-08 1993-05-12 Physiometrix, Inc. EEG headpiece with disposable electrodes and apparatus and system and method for use therewith
US5331969A (en) * 1985-07-30 1994-07-26 Swinburne Limited Equipment for testing or measuring brain activity
US20020177767A1 (en) * 2000-05-16 2002-11-28 Steve Burton Sensor for biopotential measurements
US20020182574A1 (en) * 1997-04-30 2002-12-05 Freer Peter A. Electroencephalograph Based Biofeedback System For Improving Learning Skills
EP1488740A1 (en) * 2003-06-17 2004-12-22 Instrumentarium Corporation Unitary multi-electrode biopotential signal sensor and method for making same
WO2005086574A2 (en) * 2004-02-05 2005-09-22 Motorika Inc. Rehabilitation with music

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426958A (en) * 1944-12-27 1947-09-02 Jr George A Ulett Electrode holder for use in electroencephalography
US3896790A (en) * 1972-05-01 1975-07-29 Neuronics Inc Alpha brain wave sensor
US4709702A (en) * 1985-04-25 1987-12-01 Westinghouse Electric Corp. Electroencephalographic cap

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB818711A (en) * 1955-12-06 1959-08-19 Mini Of Supply Stereotaxic device
GB1322472A (en) 1971-11-09 1973-07-04 Humetrics Corp Head harness for eeg electrodes
US4084583A (en) * 1975-04-24 1978-04-18 Siemens Aktiengesellschaft Method and apparatus for measuring the bioelectrical activity under an electrode resting on a patient
US4350164A (en) * 1980-06-03 1982-09-21 Allain Jr Joseph L Portable, life monitor, medical instrument
US5331969A (en) * 1985-07-30 1994-07-26 Swinburne Limited Equipment for testing or measuring brain activity
EP0232102A2 (en) * 1986-01-27 1987-08-12 Westinghouse Electric Corporation An electroencephalographic head set with disposable electrodes and disposable electrolyte applicator
US4928696A (en) * 1989-07-26 1990-05-29 Mindcenter Corporation Electrode-supporting headset
EP0541393A1 (en) 1991-11-08 1993-05-12 Physiometrix, Inc. EEG headpiece with disposable electrodes and apparatus and system and method for use therewith
US20020182574A1 (en) * 1997-04-30 2002-12-05 Freer Peter A. Electroencephalograph Based Biofeedback System For Improving Learning Skills
US20020177767A1 (en) * 2000-05-16 2002-11-28 Steve Burton Sensor for biopotential measurements
EP1488740A1 (en) * 2003-06-17 2004-12-22 Instrumentarium Corporation Unitary multi-electrode biopotential signal sensor and method for making same
WO2005086574A2 (en) * 2004-02-05 2005-09-22 Motorika Inc. Rehabilitation with music

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8812075B2 (en) 2004-01-08 2014-08-19 Neurosky, Inc. Contoured electrode
US8103328B2 (en) * 2007-10-01 2012-01-24 Quantum Applied Science And Research, Inc. Self-locating sensor mounting apparatus
US8626259B2 (en) 2008-04-29 2014-01-07 Board Of Governors For Higher Education, State Of Rhode Island And Providence Plantations Biomedical sensors usable on un-prepared contact surfaces
WO2009134763A1 (en) * 2008-04-29 2009-11-05 Board of Governors for Higher Education, State of Rhode Island and the Providence Plantations Biomedical sensors usable on un-prepared contact surfaces
EP2341824A1 (en) * 2008-09-12 2011-07-13 Neurosky, Inc. Contoured electrode
EP2341824A4 (en) * 2008-09-12 2014-03-05 Neurosky Inc Contoured electrode
WO2011055291A1 (en) * 2009-11-04 2011-05-12 Koninklijke Philips Electronics N.V. Device for positioning electrodes on a user's scalp
US8731633B2 (en) 2009-11-04 2014-05-20 Koninklijke Philips N.V. Device for positioning electrodes on a user's scalp
CN102596021B (en) * 2009-11-04 2015-07-15 皇家飞利浦电子股份有限公司 Device for positioning electrodes on a user's scalp
CN102596021A (en) * 2009-11-04 2012-07-18 皇家飞利浦电子股份有限公司 Device for positioning electrodes on a user's scalp
JP2013166005A (en) * 2009-11-10 2013-08-29 Japan Health Science Foundation Brain wave measuring electrode, cap with brain wave measuring electrode and brain wave measuring device
DE102010005551A1 (en) 2010-01-22 2011-07-28 Badower, Yakob, Dipl.-Ing. Sensor system for non-invasive detection of e.g. electrocardiogram signals of biological elements in head of human, has body contact electrodes coupled to shielding device for providing interference signals to shielding device
US8326396B2 (en) 2010-03-24 2012-12-04 Brain Products Gmbh Dry electrode for detecting EEG signals and attaching device for holding the dry electrode
DE102010017415A1 (en) 2010-06-17 2011-12-22 Yakob Badower Sensor system i.e. head sensor system, for non-invasive detecting e.g. ECG signals of biological origin mounted on head of human body, has measuring electrodes partly formed of thermoplastic elastomer
CN102579041B (en) * 2012-02-09 2014-04-30 上海交通大学 Arrayed flexible electroencephalogram dry electrode capable of overcoming obstacle of hair and preparation method thereof
CN102579041A (en) * 2012-02-09 2012-07-18 上海交通大学 Arrayed flexible electroencephalogram dry electrode capable of overcoming obstacle of hair and preparation method thereof
WO2015062561A1 (en) * 2013-10-30 2015-05-07 Univerzita Karlova V Praze Lekarska Fakulta V Hradci Kralove Dry electrode for registration of biopotentials from the scalp of a head
WO2016016526A1 (en) * 2014-07-30 2016-02-04 Jean-Tien Equipment for applying active elements to the skull of a patient
FR3024355A1 (en) * 2014-07-30 2016-02-05 Jean Tien EQUIPMENT FOR THE APPLICATION OF ACTIVE ELEMENTS ON THE SKULL OF A PATIENT
JP2018068436A (en) * 2016-10-25 2018-05-10 株式会社タニタ Living body measurement device
WO2019018321A1 (en) 2017-07-18 2019-01-24 Forest Devices, Inc. Electrode array apparatus, neurological condition detection apparatus, and method of using the same
EP3654840A4 (en) * 2017-07-18 2021-06-16 Forest Devices, Inc. Electrode array apparatus, neurological condition detection apparatus, and method of using the same
US11457866B2 (en) 2017-07-18 2022-10-04 Forest Devices, Inc. Electrode array apparatus, neurological condition detection apparatus, and method of using the same
US11602307B2 (en) 2017-07-18 2023-03-14 Forest Devices, Inc. Electrode array apparatus, neurological condition detection apparatus, and method of using the same
US11903731B2 (en) 2017-07-18 2024-02-20 Forest Devices, Inc. Electrode array apparatus, neurological condition detection apparatus, and method of using the same

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US20100198042A1 (en) 2010-08-05
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