ELECTRODE ARRANGEMENT FOR MEASURING BIOPOTENTIALS ON A HUMAN HEAD

Description

Technical field

[0001] Exemplary embodiments of the invention relate to a device with an electrode arrangement, as well as a method for using the device. The electrode arrangement is designed to measure electrical signals in a person's head.

[0002] Exemplary embodiments according to the invention relate, among other things, to self-applying electrode grid configurations, i.e., carrier structures with electrode arrangement, for non-invasive long-term measurement of biopotentials in humans. Background of the invention

[0003] To record electrophysiological signals, particularly electroencephalograms (EEG), electrooculograms (EOG), electrocardiograms (ECG), and electromyograms (EMG), electrodes are applied to the skin using a gel (wet electrodes) or without gel (dry electrodes) to measure the electrical activity generated by brain and muscle cells. Applying the electrodes, especially EEG electrodes on the head, while maintaining a sufficiently high signal quality has been complex, particularly with wet electrodes, making them unsuitable for self-application by laypersons. Dry electrodes are also unsuitable for EEG measurements because they have a high contact impedance, and the pressure on the scalp can cause discomfort and headaches. For ECGs, there are so-called fixed gel electrodes, also known as wet electrodes, which can be easily applied to the skin as individual electrodes, similar to an adhesive bandage.The moderately viscous gel lens, in addition to its electrolyte effect, has adhesive properties, allowing the electrode to adhere better to the skin than wet electrodes with gel coating or dry electrodes. For EEG and EOG recording, positions on the head / face must be used (near the eyes or near the brain as the signal source), with these positions maintained within a tolerance of a few centimeters to capture specific signals of brain activity and eye movement.

[0004] Polysomnography (PSG) is the standard diagnostic procedure for identifying sleep stages. Various biosignals are continuously recorded during sleep, usually overnight in a sleep laboratory. These include recordings of EEG, EOG, EMG, ECG, respiratory flow, respiratory effort, oxygen saturation, body position, and video. Electrode positions for recording EEG, EOG, and EMG are typically those found in [reference to a specific example of a sleep study]. Fig. 14 The configuration shown is used. Minor variations in configuration are possible. Fig. 14 This shows a conventional electrode placement during polysomnography.

[0005] EOG_R and EOG_L record eye movements. GND and REF are necessary for measuring the EEG with a differential amplifier, where potential differences relative to REF and GND are determined. F4, F3, C4, C3, O1, and O2 are the positions of the EEG electrodes, based on the 10-20 system commonly used in EEG, whereby at least one occipital, one central, and one frontal position are necessary to determine sleep stages and are supplemented by an alternative position during measurement. M1 and M2 are used for classic re-referencing to the mastoid process. The electrodes on the chin (EMG1, EMG_REF, EMG2) are necessary for recording muscle movements and muscle tension. The signals from electrodes F4, F3, C4, C3, O1, and O2 are used in combination and relative to REF and GND as so-called EEG channels for determining sleep stages. The placement of all electrodes is very time-consuming and can only be done by trained personnel.

[0006] For EEG monitoring outside of clinical and research laboratory settings, where individuals self-apply electrodes, only dry electrode systems are currently available for fixed electrode configurations. While dry electrode solutions exist for sleep monitoring, they do not provide EOG or EMG in the manner proposed here (see, for example, https: / / dreem.com / , July 22, 2021 [Arnal, PJ, Thorey, V., Ballard, ME, Hernandez, AB, Guillot, A., Jourde, H., & Sauvet, F. (2019); "The Dreem headband as an alternative to polysomnography for EEG signal acquisition and sleep staging."; BioRxiv, 662734] or https: / / www.philips.de / ce / hs / sleep-solutions / smartsleep-advocacy, July 22, 2021). Wet electrodes for high signal quality are currently only applied by trained personnel and not by untrained individuals alone. Helmet / headphone solutions that use moist sponges are also available.

[0007] Printed electrode systems are available on the market: (1) cEEGrid With these electrodes, the gel must be pre-applied immediately before the measurement; it is not possible to apply the grid yourself, this requires a trained person. The substrate material of the printed electrode is only flexible in one direction, so it does not conform well to a three-dimensional shape (e.g., a bony protrusion on the head). It has sharp edges, which can impair wearing comfort in the ear area. (see https: / / tmsi.wiljekoffie.dev / product / ceegrid (July 21, 2021); Debener, S., Emkes, R., De Vos, M. & Bleichner, M.; "Unobtrusive ambulatory EEG using a smartphone and flexible printed electrodes around the ear."; Sci. Rep. 5, 16743 (2015); and Bleichner, MG & Debener, S.; "Concealed, unobtrusive ear-centered EEG acquisition: cEEGrids for transparent EEG."; Front Hum Neurosci.11, (2017)) (2) xTrodes These are dry electrodes, and it is not known whether or to what extent the grid can be self-applied. (see https: / / xtrodes.com / ; WO 2017 / 090050 A1; and "Home monitoring of sleep with a temporary-tattoo EEG, EOG and EMG electrode array: a feasibility study." by Shustak, S., Inzelberg, L., Steinberg, S., Rand, D., Pur, MD, Hillel, I., ... & Hanein, Y. (2019), Journal of neural engineering, 16(2), 026024) (3) Bittium The electrode system is designed for use in emergency medical care in its product form and is therefore not intended for self-application. However, the patent specification listed below also mentions other applications, such as sleep monitoring. However, it is not stated that the grid can be applied by the user themselves. Another person, such as a trained nurse, is involved. (see https: / / shop.bittium.)com / product / 28 / bittium-brainstatus-eeg-electrode-10pcs (July 21, 2021) and US2015238106A) .

[0008] The publication [V. Toral et al., "Cost-Effective Printed Electrodes Based on Emerging Materials Applied to Biosignal Acquisition", in IEEE Access, vol. 8, pp. 127789-127800, 2020, doi: 10.1109 / ACCESS.2020.3008945] presents methods using various materials for the creation of printed electrode systems, especially for applications in ECG, EMG and EOG.

[0009] Document US 2010 / 041962 A1 discloses a headset for recording the electrical activity of the brain with a flexible band that has at least one stretchable section allowing the distance between a first end and a second end to be selectively changed. The headset may also include flexible circuits within the flexible band.

[0010] Document US 2020 / 383594 A1 discloses electrode carriers for electrophysiological measurements, comprising a substrate and a plurality of contact points attached to a substrate surface. The substrate has at least two non-stretchable sections for receiving the contact points, the sections being connected to each other by a stretchable section.

[0011] In light of this, there is a need for a concept that enables a self-applying electrode array and offers a better compromise between ease of use, high positional accuracy of the electrodes on a user's head, high adhesion of the electrode array to the user's head, high signal quality, and comfortable wear over several hours.

[0012] This problem is solved by the independent patent claims.

[0013] Further developments in accordance with the invention are defined in the dependent claims. Summary of the invention

[0014] According to a first aspect of the present invention, the inventors have recognized that a problem arising when self-application of an electrode array results from the fact that, until now, the electrodes could not be easily and efficiently positioned correctly by the user. According to this first aspect, this difficulty is overcome by providing a support structure for the electrode array, which connects the individual electrodes of the array. The support structure predefines distances between the electrodes and / or the positions of the electrodes relative to each other. For example, the support structure spans a matrix on which the electrodes of the electrode array are arranged at predefined positions. This enables simple, efficient, and precise positioning of the electrodes by the user, as the support structure provides assistance.By attaching the carrier structure to the user's head or face, the electrodes, arranged at predefined positions on the carrier structure, are automatically positioned correctly within a tolerance range. The special design of the carrier structure, which connects the electrodes of the electrode array, ensures a high level of wearing comfort and ease of handling. This device is particularly advantageous compared to the placement of individual electrodes, as the latter requires more effort during installation and offers less certainty in the reproducibility of the electrode configuration. The proposed solution is intended to address these issues and allow for faster and simpler electrode installation, especially by the user themselves, eliminating the need for another (trained) person to be present.

[0015] Furthermore, the inventors discovered that it is advantageous for the support structure to have a flexibility that depends on whether or not the user exerts force on it. This varying flexibility allows for simple, efficient, and precise positioning of the electrodes to adapt to the facial structures of different users.

[0016] The support structure should be dimensionally stable, even without user force, so that it does not bend or only minimally bend under the influence of gravity. This dimensional stability can be achieved, for example, by using a material such as polyurethane foam and a specific thickness, e.g., between 0.5 mm and 2 mm. Alternatively, the support structure can incorporate a removable stiffening element designed to stabilize its shape. This removable stiffening element can, for example, reinforce the support structure during the user's application process. This entire structure will be referred to collectively as the support structure in the following text.The support structure, for example, spans a matrix which, when aligned in a plane perpendicular to gravity, bends by a maximum of 15 cm, 10 cm, 8 cm, or 6 cm in the direction of gravity over a length of, for example, 10 cm. The support structure thus exhibits, for example, high rigidity or low compliance with gravity. This is based on the idea that the rigidity of the support structure allows the user to easily and efficiently position it precisely on their head or face without the structure collapsing and complicating the application. Under the influence of gravity, the shape of the support structure, or the relative arrangement of the electrodes to each other, deviates from the shape of the support structure when it is aligned perpendicular to gravity.The relative arrangement of the electrodes to each other deviates by a maximum of 2 cm or 3 cm when a resultant force of zero Newtons acts on the support structure (the shape of the support structure or the relative arrangement of the electrodes in a state of force equilibrium). If, however, the support structure is aligned parallel to gravity, the deviation is a maximum of 2 cm or 1 cm. This shape stability of the support structure is particularly relevant as long as the device is not attached to the user's head surface, i.e., to the user's face and behind the user's ear.

[0017] Under the external force applied by the user, however, the support structure should be deformable so that it can be adapted to the user's facial structure. This allows, for example, unevenness caused by bone structures to be covered completely, ensuring good adhesion. Furthermore, the electrode position of the first electrode on the face of one user can be essentially aligned with that of a second user. This ensures that, despite differing head circumferences, the electrodes can be attached to the user's face at predetermined positions within a tolerance range of up to 1 cm or 2 cm. The support structure is designed, for example, to allow deformation within a range of, for example, at least 2% to a maximum of 10% to 20%, depending on the material.This is based on the idea that the carrier structure assists the user in positioning the electrodes on their face or head, and that its low deformability dictates the electrode positions. The user can only minimally adjust the shape of the carrier structure to their specific facial structure. The carrier structure is thus designed, for example, to conform to the user's head or facial anatomy, so that predefined electrode positions on the carrier structure correspond to predefined points on the user's head or face.

[0018] Accordingly, a device according to a first aspect of the present invention comprises a support structure and an electrode arrangement with a plurality of electrodes for measuring electrical signals on a facial surface of a user's head and furthermore for measuring electrical signals behind a user's ear. The support structure defines at least a partial relative position of the electrodes to one another. The support structure is dimensionally stable within a tolerance range without external force from the user and deformable under external force from the user in order to change the distance between two adjacent electrodes, i.e., two electrodes connected to each other via a bridge of the support structure, and to adapt to facial and head structures over their entire surface, i.e., lying flat against the respective surface. A distance between two adjacent electrodes is, for example,The support structure is adaptable by stretching, compressing, or twisting the bridge that connects the two electrodes. A particular advantage is that the user can adapt the support structure to contours on their face or head due to its deformability. This allows the support structure to be applied across the entire surface, ensuring, for example, a robust adhesive bond between the support structure and the face or head. In other words, the support structure can remain dimensionally stable within a tolerance range without external force from the user, and can be deformed under external force from the user to conform completely to facial and / or head contours, ensuring that the support structure lies flat against the face and / or head surface.The support structure is, for example, in contact with the respective surface between the individual electrodes of the electrode array, e.g., across a flat area. The support structure is designed to position at least part of the electrode array on the facial surface and another part of the support structure behind the user's ear.

[0019] The electrode array features wet electrodes, such as solid gel electrodes. Therefore, the electrode array consists of a large number of wet electrodes. Wet electrodes offer a higher signal quality than dry electrodes because the highly viscous conductive gel penetrates the skin layers more effectively, thus reducing impedance. When using wet electrodes, the gel, such as conductive gel or solid gel, is pre-applied, for example, as a conductive gel lens or solid gel lens. The pre-applied conductive gel or solid gel is protected, for example, by a removable protective element, such as a protective film. Pre-application of the gel eliminates the need for the user to apply it themselves, thus simplifying the application of the device.Furthermore, the inventors recognized that the use of wet electrodes improves wearing comfort compared to dry electrodes, as no pressure needs to be applied to connect the electrode to the skin, resulting in a significantly lower electrode weight. When using dry electrodes, a force of at least 1 N to 4 N (1 Newton to 4 Newtons) or more must be applied to the skin to measure signals with an impedance in the range of 250 to 50 kΩ. With wet electrodes, however, the connection between the electrode and the skin is achieved via an electrolyte gel, such as a solid gel. This allows the support structure to be designed so that the electrodes can be pressed onto the skin with little or no force. This means that a maximum force of 0.2 N is sufficient to detect signals with an impedance below 50 kΩ or much lower.This low force can be achieved, for example, by adhering the carrier structure with the electrode array to the user's facial surface. Thus, wet electrodes can capture signals with a better signal-to-noise ratio than dry electrodes. In a further advantageous embodiment, the electrode surface of each electrode in the multitude of electrodes should be less than 1 cm in diameter to allow for the placement of the numerous electrodes on the face and head. This is advantageous for long-term applications lasting several hours, overnight, or for several days.

[0020] According to one embodiment, the support structure follows the facial surface as a human facial shape, and the multitude of electrodes are arranged on the support structure. The support structure follows the facial surface, for example, in that it forms a matrix that follows prominent facial lines. Prominent facial lines include, for example, the eyebrow, the cheekbone (i.e., the zygomatic bone), the curve behind the ear, and the mandible. The support structure follows the facial surface, for example, in that it forms a matrix that follows the shape of the user's eyebrow and the shape of the ear behind the user's ear. The support structure is designed, for example, to position the multitude of electrodes at prominent points on the user's facial surface.An upper cheekbone, a point in front of the tragus of the ear, a point on the forehead vertically above the nasion, the chin, and / or the mastoid behind the ear are examples of prominent points. A first electrode position, assigned to a first electrode of the multiple electrodes, corresponds, for example, to the position of a first prominent point on the facial surface; and a second electrode position, assigned to a second electrode of the multiple electrodes, corresponds, for example, to the position of a second prominent point on the facial surface; and a third electrode position, assigned to a third electrode of the multiple electrodes, is determined from the first and second electrode positions on the facial surface, for example, at a predetermined position, within a tolerance range defined by the support structure.The first and second electrode positions, for example, represent reference positions for positioning further electrodes within the multitude of electrodes. The tolerance range results, for example, from the deformability of the support structure under the force exerted by a user, as explained above. This deformability by the user results in a tolerance range of a maximum of 2 cm or a maximum of 1 cm around a position on the facial surface of the third electrode. The support structure is designed, for example, to position the multitude of electrodes at a corresponding multitude of predetermined positions, such as prominent points, on the user's head surface, i.e., on the facial surface and / or behind the ear. The tolerance range defines, for example, a range of a maximum of 2 cm or a maximum of 1 cm around a predetermined position of the respective electrode on the head surface. The tolerance range specifies, for example,The design considers how reproducibly the support structure positions the electrodes of the electrode array at key points on different heads, e.g., with varying head circumferences, and how precisely these key points are reached. The electrode array does not need to be positioned more precisely than this. High signal quality is achieved within this tolerance range. The support structure is designed, for example, to connect the third electrode to the first and second electrodes via a connecting bridge, the shape and / or length of which depends on the position of the first and second electrodes. Optionally, the shape and / or length of the connecting bridge also depends on the facial shape. This ensures that the connecting bridge does not, for example, run over an eye, ear, nose, or mouth of a user.The specially shaped carrier structure and the unique arrangement of the numerous electrodes on this structure allow for highly comfortable and precise placement of the electrodes on the user's face. This precise positioning ensures high signal quality at positions on the head specifically defined for each application.

[0021] According to one embodiment, the first prominent point on the facial surface corresponds to an upper cheekbone, and the second prominent point corresponds to a position in front of the tragus of one of the user's ears. The choice of these two points as reference positions for positioning further electrodes, such as the third electrode, is based on the fact that these two points are easily palpable on the facial surface and can therefore be positioned very precisely by the user. The inventors recognized that, using these two points, the support structure with the electrode array can be aligned very precisely on the user's facial surface. Because the reference positions (i.e., the first electrode position and the second electrode position) correspond to characteristic points on the user's face, for example,Due to the shape of the support structure, the electrodes of the multiple electrodes are arranged relative to the reference points on the support structure and can be easily positioned at predetermined positions on the facial surface. The remaining electrodes (e.g., the fourth electrode up to the nth electrode, where the multiple electrodes comprise n electrodes) of the multiple electrodes are arranged, for example, on the support structure relative to the first and second electrodes. This allows the user to very easily and efficiently apply the electrode array precisely to their facial surface, thereby achieving high signal quality.

[0022] According to one embodiment, the support structure comprises a connecting bridge (e.g., a first connecting bridge) that at least partially connects the first electrode position and / or the second electrode position to the third electrode position, wherein the third electrode position corresponds, within a tolerance range of 1 to 2 cm determined by the support structure, to a position on the forehead of the facial surface in an area of ​​1 cm to 3 cm above the eyebrow line, vertically above a nasion of the user. The third electrode position should thus correspond to a position in the area of ​​1 cm to 3 cm above the eyebrow line, vertically above the user's nasion. However, the inventors recognized that high signal quality can also be achieved if the third electrode position lies within the tolerance range of 1 to 2 cm on both sides, perpendicular to this area.The tolerance range extends perpendicular to the area directly above the nasion, or perpendicular to an extension line from the tip of the nose to the nasion, and is, for example, a maximum of 1 cm or a maximum of 2 cm. Optimal signal quality is achieved when the third electrode position is located 2 cm above the eyebrow line, directly above the user's nasion. The connecting bridge of the carrier structure defines the third electrode position, allowing the user to place the third electrode very precisely on their facial surface. While the connecting bridge is designed to allow for a certain tolerance range, it simultaneously prevents the user from placing the electrode outside a predetermined area on the facial surface.This ensures that the user can easily apply the third electrode of the electrode assembly, as the connecting bridge of the support structure ensures that the third electrode is positioned on the user's facial surface in such a way as to achieve good signal quality from a specifically defined location for the electrical signal measured with the third electrode.

[0023] According to one embodiment, the support structure comprises a connecting bridge (e.g., a third connecting bridge) that at least partially connects the first electrode position and / or the second electrode position to a fourth electrode position, which is associated with a fourth electrode of the plurality of electrodes, and wherein the fourth electrode position corresponds, within a tolerance range determined by the support structure, to a position behind the ear, such as a predetermined position like the user's mastoid. The tolerance range defines, for example, a maximum area of ​​1 cm or a maximum of 2 cm around a predetermined position behind the ear. Optionally, further electrodes of the plurality of electrodes, such as a sixth, seventh, eighth, and ninth electrode, are arranged on the connecting bridge.The positions of the remaining electrodes correspond, within the tolerance range determined by the carrier structure, to a corresponding number of positions behind the user's ear. For example, the sixth, seventh, eighth, and ninth electrodes are arranged on the connecting bridge relative to the fourth electrode position. The shape and / or length of the connecting bridge depends, for example, on the first and second electrode positions. The connecting bridge is designed, for example, to define the fourth electrode position relative to the first and / or second electrode positions. The connecting bridge extends, for example, from the user's face above the ear to behind the ear, following the shape of the ear. Optionally, the third and first connecting bridges share a common section. This common section branches, for example, to the first and third connecting bridges.At the point of branching, for example, another electrode of the multitude of electrodes is arranged.

[0024] According to one embodiment, the support structure comprises a connecting bridge (e.g., a second connecting bridge) that at least partially connects the first electrode position and / or the second electrode position to a fifth electrode position, which is associated with a fifth electrode of the plurality of electrodes, and wherein the fifth electrode position corresponds, within a tolerance range determined by the support structure, to a position, e.g., a predetermined position, on the chin of the user's face. The tolerance range defines, for example, a range of a maximum of 1 cm or a maximum of 2 cm around a given or predetermined position on the chin.The connecting bridge is designed to be deformed by the user to adapt the fifth electrode position to the user's facial structure, ensuring that the fifth electrode position corresponds to a position within the tolerance range around the user's chin. The shape and / or length of the connecting bridge depends, for example, on the first and second electrode positions. The connecting bridge is designed, for example, to define the fifth electrode position relative to the first and / or second electrode positions.

[0025] According to one embodiment, the support structure includes an adhesive material for fixing the plurality of electrodes and the support structure to the facial surface. Optionally, the adhesive material is covered by a removable protective film. According to another embodiment, the plurality of electrodes further include an adhesive electrolyte gel for fixing the plurality of electrodes and the support structure to the facial surface. The adhesive electrolyte gel is covered, at least partially, by a removable protective film. The electrodes with the adhesive electrolyte gel and the adhesive material can, for example, have a common removable protective film or separate protective films. The electrodes with the adhesive electrolyte gel are so-called wet electrodes. The adhesive material is, for example, arranged on the side of the support structure on which the electrode array is also located.

[0026] According to one embodiment, the protective film covering the adhesive material and, optionally, the adhesive electrolyte gel, comprises a plurality of protective film sections that can be detached independently of each other from the carrier structure and the plurality of electrodes. This allows individual sections of the carrier structure and the electrode arrangement to be easily and efficiently applied sequentially to the user's face, preventing parts of the carrier structure that are applied later from failing to adhere to each other. Optionally, a first protective film section of the plurality of protective film sections covers a first subset of the plurality of electrodes and the carrier structure, and a second protective film section of the plurality of protective film sections covers a disjoint second subset of the plurality of electrodes and the carrier structure. The first protective film section covers, for example,The first section of the carrier structure is covered by a protective film, and the second section covers, for example, a second section of the carrier structure, with the first and second sections not overlapping. The first subset of the multiple electrodes is arranged, for example, in the first section of the carrier structure, and the second subset of the multiple electrodes is arranged, for example, in the second section of the carrier structure. Optionally, certain sections of the carrier structure can also be designed to be non-adhesive, for example, for the area above the ear. Thus, for example, an area of ​​the carrier structure located on the side where the electrode array is positioned can be free of adhesive material.

[0027] According to the invention, the support structure is designed as a network structure, e.g., a matrix, with branching connecting bridges that follow the contours of the facial surface. These branching connecting bridges extend, for example, along prominent lines and / or shapes of the human face. The branching connecting bridges follow the contours of the facial surface in such a way that they follow the shape of the user's eyebrow, e.g., along the eyebrow and along the cheekbone around the eye, and behind the user's ear, they follow the shape of the ear. Optionally, the connecting bridges can also extend along the lower jaw to the user's chin. Because the connecting bridges follow the contours of the facial surface and are deformable under force, a high level of wearing comfort is achieved for the user.

[0028] The branched connecting bridges have a width that, according to the invention, corresponds to at most three times, and in further embodiments at most 1.5 times or twice, the diameter of an electrode in the plurality of electrodes. The narrow design of the connecting bridges further increases wearing comfort, as only a very small portion of the facial surface is in contact with the support structure. This increased comfort allows the device to be worn for extended periods, such as overnight. Furthermore, the inventors recognized that the narrow connecting bridges simplify adaptation to user-specific facial shapes.

[0029] According to one embodiment, a connecting bridge of the branching connecting bridges is bent at one end, so that the support structure has a curved end piece designed to be placed behind the user's ear, and wherein the connecting bridge is designed to extend from the user's face above the ear to the curved end piece. At least one electrode of the plurality of electrodes is arranged on the curved end piece. The inventors recognized that the route of the connecting piece above the ear facilitates the user's independent application of the device to the facial surface, since the connecting bridge is designed, for example, to be placed on the upper earlobe of the user during application to facilitate correct alignment.The device is supported on the ear via the connecting bridge, which allows for efficient arrangement and application of the remaining branching connecting bridges on the face, as it eliminates the need to support the connecting bridge to the user's ear with one hand. The curved end piece is designed so that the user can hook it behind their ear, thus stabilizing the device during self-application and at least partially orienting it into the correct position on the face. Therefore, the connecting bridge facilitates self-application and reduces the time required for application.

[0030] In the area of ​​the connecting bridge that runs above the ear, for example, no adhesive material is applied, or a non-removable protective film is placed to cover the adhesive material in this area. This prevents the device from adhering to hair and thus optimizes wearing comfort. The inventors realized that the connecting bridge can be stably placed on the upper base of the ear, making it easier for the user to apply the device to their face independently.

[0031] According to one embodiment, the support structure has an ear-shaped section designed to extend above the user's ear. In other words, part of the support structure extends above the user's ear. This section above the ear can be considered the ear-shaped section. The inventors recognized that extending the support structure above the ear facilitates the user's independent application of the device to the facial surface, as the ear-shaped section is designed to be placed, for example, on the upper part of the user's ear. The device is supported on the ear via the ear-shaped section, which allows for efficient positioning and application of the remaining support structure to the facial surface.

[0032] According to one embodiment, the ear area of ​​the support structure forms part of a connecting bridge that, starting from at least a first electrode position associated with a first electrode of the plurality of electrodes, and / or a second electrode position associated with a second electrode of the plurality of electrodes, defines a fourth electrode position associated with a fourth electrode of the plurality of electrodes. The fourth electrode position corresponds to a position behind the user's ear. Optionally, the fourth electrode represents a reference electrode (REF) or a ground electrode for the plurality of electrodes. Alternatively, for example, the fourth electrode can represent a reference electrode (REF) and an electrode located adjacent to this electrode, e.g., electrode 110 5, can represent a ground electrode (GND).

[0033] According to one embodiment, the support structure or a form of the support structure is designed to position the plurality of electrodes at a corresponding plurality of positions on the facial surface. The specific shape of the support structure defines, for example, the positions of the electrodes arranged on the support structure on the facial surface. The plurality of positions is configured for capturing electrical signals on the facial surface for at least one linear combination of electrical signals to map signals from a predetermined head region of the user. The shape of the support structure, as well as, for example, the positioning of the electrodes of the electrode arrangement on the support structure, enables the capture of electrical signals from different head regions of the user, such as different brain and muscle regions. The arrangement of the electrodes on the support structure is designed, for example, to...Based on linear combinations of the electrical signals measured by the electrodes, an electroencephalogram (EEG) can be recorded for various brain regions [e.g., in a prefrontal area (i.e., in an anterior region of the frontal lobe (Fp)), frontal area (i.e., on the forehead or in the frontal lobe (F)), temporal area (e.g., temporal (T)), parietal area (P), in a region of the back of the head (i.e., occipital (O)), and in a central brain region (i.e., central (C))], an electrooculogram (vertical, horizontal, and diagonal), and / or an electromyogram, particularly in a region of the chin. Because the carrier structure is shaped so that the electrodes arranged on it correspond to predetermined positions on the user's facial surface, the linear combination of the measured signals can also be used to record head regions or...Brain and muscle regions of the user are mapped, even where no electrode directly measures a signal. This allows the number of electrodes to be minimized, thus reducing costs and increasing user comfort, as fewer areas of the face are covered by the device, ideally only hairless skin areas are used, and the reduced number of electrodes also reduces the device's weight. Finally, the signal captured in this way also contains information about heart activity, so an electrocardiogram (ECG) can be derived from the data via appropriate signal analysis.

[0034] According to one embodiment, the device has a signal output configured to provide an output signal based on the electrical signals measured by the plurality of electrodes. The signal output is coupled to the electrodes of the device's electrode array, for example, via electrical leads. Optionally, the device further includes a signal amplifier configured to receive the measured electrical signals from the signal output. The device includes, for example, a mounting means that defines the position of the signal amplifier on the back of the user's head, arm, shoulder, chest, or neck.

[0035] According to one embodiment, the fastening device is a neckband or scarf designed to attach the signal amplifier to the user's neck below the mastoid process and between the sternocleidomastoid and trapezius muscles. This is based on the understanding that this position of the signal amplifier results in a high level of user comfort. Sleeping with the device in this position is also comfortable. Thus, this positioning of the signal amplifier improves the device's suitability for use over several hours, such as overnight, or even over several days for long-term screening.

[0036] According to one embodiment, the support structure comprises polyurethane material (such as polyurethane film), polymer material, and / or silicone material. The support material is stretchable or elastic and, for example, flexible. This flexibility allows it to conform to irregularities in facial and head structures. If the structure (e.g., the support structure with a maximum thickness of 0.1 mm, 0.3 mm, or 0.5 mm, such as 0.2 mm) is applied to a radial protrusion (here assumed to be a cylinder) with a diameter of, for example, 0.When placed 5 cm from the surface and 1 cm high, the support material can simultaneously come to rest flat on the circular surface and at four points on the cylindrical surface, either under its own weight due to gravity or through the application of a small force (<1 N). Two of these areas on the cylindrical surface are opposite each other, and the lines connecting the opposite surfaces are perpendicular to each other, without damaging the support structure (tearing or breaking). The structure follows the 90° angle from the circular surface to the cylindrical surface with a tight radius of no more than 1 mm. Flexibility can be understood, for example, as the ability of a structure to be deformed simultaneously along two perpendicular lateral directions in one thickness direction without being damaged, and / or the ability of the structure to be twisted multiple times without being damaged.For example, when a torsional moment acts on the structure to twist it multiple times around an axis perpendicular to the thickness direction.

[0037] According to one embodiment, the support structure comprises polyurethane material (such as polyurethane film), polymer material, and / or silicone material. The support material is stretchable or elastic and, for example, flexible. The electrodes are connected by conductive traces. The conductive traces have a looped path on or within the support structure so that they lengthen correspondingly when the support structure is stretched. Because the conductive traces have a looped path, such as a wave-like, meandering, or jagged shape, the device can be adapted to users with varying facial features, as the conductive traces do not tear when the support structure is deformed by external force applied by the user. The conductive traces are, for example, integrated into the support material or arranged on a surface of the support structure.The conductive traces can be manufactured on or within the substrate using methods also employed in printed circuit board production. For example, the conductive traces can be printed or etched onto the substrate.

[0038] According to one embodiment, the support structure is designed to increase the distance between two electrodes of the electrode arrangement by a maximum of 20%, 15%, 10%, or 5%. This distance refers to the gap between two adjacent electrodes between which no further electrode is arranged on the support structure. The increase is caused, for example, by an external force applied to the support structure by the user. The ability to increase the distance by a maximum of 20%, 15%, 10%, or 5% is due, among other things, to the stretchable or elastic support material and the looped conductor tracks. It is advantageous if the support structure is designed to increase the distance between two electrodes by, for example, at least 1%, 3%, or 5%. It is particularly advantageous if the support structure is designed to increase the distance between two electrodes within a range of, for example, 3% to 10% or 1% to 5%.The minimum requirement for the support structure, that it should be designed to lengthen the distance by at least 1%, 3%, or 5%, ensures that the device is comfortable for users, adapts well to uneven surfaces, and is suitable for different face shapes. The maximum limit, that the support structure should be designed to lengthen the distance by a maximum of 20%, 15%, 10%, or 5%, prevents the user from accidentally positioning the electrodes of the electrode array mounted on the support structure in positions on the facial surface that deviate by more than a certain tolerance range from the electrode positions specified by the support structure. For details regarding the tolerance range, please refer to the explanations above.The possible extension of the distance is limited, among other things, by the play generated in the conductor tracks by the curved guide in or on the support structure and by the extensibility and / or elasticity of the support material.

[0039] According to one embodiment, the support structure comprises polyurethane foam as the carrier material and optionally an additional polyurethane film (e.g., as a stiffening element). The carrier material is extensible or elastic and, for example, flexible. This flexibility allows it to conform to irregularities in facial and head structures. If the structure (e.g., the support structure with a thickness in the range of 0.5 mm to 2 mm) is placed on a radial protrusion (here assumed to be a cylinder) with a diameter of, for example, 0.5 cm and a height of 1 cm, the carrier material can simultaneously be brought into contact with the circular surface and four points on the cylinder's lateral surface by applying only a small force (<1 N). Two of these points on the lateral surface are opposite each other, and the lines connecting the opposing surfaces are perpendicular to each other, without damaging the support structure (tearing or breaking).The structure follows the 90° angle from a circular surface to a cylindrical surface with a close radius of no more than 1 mm. Flexibility can be understood, for example, as the ability of a structure to be deformed simultaneously along two mutually perpendicular lateral directions in one thickness direction without being damaged, and / or the ability to be twisted multiple times around itself without being damaged, i.e., when, for example, a torsional moment acts on the structure to twist it multiple times around an axis perpendicular to the thickness direction.

[0040] According to one embodiment, the support structure has polyurethane foam as the carrier material and optionally an additional polyurethane film (e.g., as a stiffening element). The carrier material is extensible or elastic and, for example, flexible. The electrodes are connected to cables. The cables are guided with clearance along a surface of the support structure facing away from the electrode arrangement. This clearance limits the force transmission of any elongation of the support structure to the cables. The clearance corresponds, for example, to a coiled or loose routing of the cables along the support structure. The support structure can, for example, have spaced-apart clamping points designed to fix the cables to the support structure, i.e., clamp them in place, whereby the cables between the clamping points are not fixed to the support structure and have a greater length than the distance between the respective clamping points. Alternatively, the support structure can, for example,The device features spaced-apart guide rings designed to guide the cables along the support structure. The cables run loosely through the guide rings, and the length of the cables between the guide rings is greater than the distance between them. Similar to the description above for the conductor tracks, the elastic support material and the play in guiding the cables along the support structure allow the device to adapt to users with varying facial features, as the cables do not break when the support structure is deformed by external force applied by the user.

[0041] According to one embodiment, the support structure is designed to increase the distance between two electrodes of the electrode arrangement by a maximum of 20%, 15%, or 10%. This distance refers to the distance between two adjacent electrodes between which no further electrode is arranged on the support structure. The increase is caused, for example, by an external force applied to the support structure by the user. The fact that the distance can be increased by a maximum of 20%, 15%, or 10% is due, among other things, to the stretchable or elastic support material and the clearance provided by the cables along the support structure. It is advantageous if the support structure is designed to increase the distance between two electrodes by, for example, at least 1%, 3%, or 5%. It is particularly advantageous if the support structure is designed to increase the distance between two electrodes by, for example,The minimum requirement for the support structure is that it should be designed to lengthen the distance by at least 1%, 3%, or 5%, ensuring high user comfort and making the device suitable for users with different facial shapes. The maximum limit, that the support structure should be designed to lengthen the distance by a maximum of 20%, 15%, or 10%, prevents the user from accidentally positioning the electrodes of the electrode array mounted on the support structure in positions on the facial surface that deviate by more than a certain tolerance range from the electrode positions specified by the support structure. The tolerance range is explained above.The possible extension of the distance is limited, among other things, by play in the routing of the cables along the support structure and by the extensibility or elasticity of the support material.

[0042] According to one embodiment, the support structure is adapted to different head circumferences by means of the stretchable or elastic support material and, for example, by the special routing of the conductor tracks or cables in, on, or along the support structure, wherein the different head circumferences differ by a maximum of 5 cm. According to an alternative embodiment, the support structure is adapted by means of the elastic support material and, for example, by the special routing of the conductor tracks or cables in, on, or along the support structure for positioning at least part of the electrode arrangement on the facial surface of the user's head with a head circumference in the range of 50 cm to 55 cm, 55 cm to 60 cm, or 60 cm to 65 cm.

[0043] According to one embodiment, the support structure has a detachable stiffening element on a side facing away from the electrode arrangement. This stiffening element is designed to stiffen the support structure, at least locally. The stiffening element can be made of, for example, paper, polyurethane foam, or polyimide. The stiffening element simplifies the user's ability to position the device independently on their face, as it prevents the support structure from changing shape under the influence of gravity. By preventing the shape of the support structure from changing, it guides the user in determining the positions on their face where the electrodes of the electrode arrangement should be fixed, since the shape of the support structure defines the electrode positions on the face.Another advantage of the stiffening element is that it prevents the support structure from bending in such a way that different parts of the support structure stick together, thereby impairing the functionality of the device. The stiffening element is detachable, so that it can be removed after the structure has been attached, thus fully preserving the support structure's flexibility and elasticity for a complete conformity to the face.

[0044] According to one embodiment, the stiffening element is designed to maintain a deformation of the support structure caused by an external force applied by the user, even after the external force has ceased. This increases wearing comfort. Wearing comfort is particularly enhanced when the stiffening element is positioned, for example, on the support structure in an area corresponding to the area around the user's eye or cheek. For instance, no stiffening element should be positioned in the chin area, as wearing comfort, especially for the user's mouth movements, is improved if the support structure in this area is reversibly elastic or slightly stretchable.

[0045] According to one embodiment, the support structure has at least one extension at a position where an electrode of the electrode arrangement is located. This extension is, for example, a bulge of the support structure, a branching portion of the support structure that is at most 2 cm, 1.5 cm, or 1 cm long, or an elongation of the support structure that is at most 2 cm, 1.5 cm, or 1 cm long. The support structure extends or branches, for example, within a plane, and an extension extends laterally out of this plane. The extension does not extend orthogonally to the plane. For example, the surface of the support structure on which the electrode is located defines a plane, and the extension extends within this plane. The extension extends, for example, orthogonally to a normal vector of the support structure at a position where an electrode of the electrode arrangement is located.Optionally, adhesive material is applied to the extension to improve the adhesion of the electrodes to the user's face. Without adhesive, the extension facilitates handling of the device, particularly the independent application and removal of the electrode from the user's face. Firstly, the extension makes it easier to grasp the electrode without touching the electrode or its sensitive sensor unit. Secondly, the extension stabilizes the electrode on the face when the user positions it.

[0046] According to one embodiment, the plurality of electrodes includes active electrodes that incorporate a circuit configured to perform impedance conversion of the measured electrical signal and / or to amplify the measured electrical signal. Because the electrode arrangement includes active electrodes, the signal is of higher quality with respect to the signal-to-noise ratio and less susceptible to signal disturbances due to electrode movement.

[0047] Alternatively or additionally to active electrodes, the device can also include passive electrodes. If the electrode array includes passive electrodes, an impedance converter and / or signal amplifier is usually required, which should be positioned on the user's body near the device's electrode array. Optionally, the device can include an impedance converter and / or signal amplifier that is connected to a signal output. The use of passive electrodes has the advantage of reducing the weight of the support structure and the electrode array compared to using active electrodes. This increases the user's comfort on the face.

[0048] Another embodiment relates to a device comprising a support structure and an electrode arrangement with a plurality of electrodes for measuring electrical signals on the facial surface of a user's head and behind the user's ear. The electrodes in the plurality of electrodes are wet electrodes (with gel or solid gel). The support structure defines at least a partial relative position of the electrodes to one another and is designed to be in contact with the user's facial surface over a large area between the individual electrodes of the electrode arrangement. Thus, the specific design of the support structure enables it to lie flat on the facial surface and to follow or adapt to the facial and head structures.Furthermore, the support structure is designed to position at least part of the electrode array on the facial surface and behind the ear. The electrodes are connected either by conductive traces that have a looped path on or within the support structure, or by cables that are guided with slack along a surface of the support structure facing away from the electrode array. The looped path of the conductive traces, or the slack in the cable routing, allows the support structure to expand without damaging the conductive traces or cables, as the conductive traces or cables can lengthen in proportion to the expansion of the support structure. The slack in the cables along the support structure limits, for example, the force transmission from expansion of the support structure to the cables. The device is based on the same principles as the device described above.The device can be supplemented with all the features and functions that are also described with regard to the device described above.

[0049] Another embodiment relates to a device comprising a support structure and an electrode arrangement with a plurality of electrodes for measuring electrical signals on the facial surface of a user's head and behind the user's ear. The electrode arrangement is, for example, arranged on a first side or surface of the support structure. The electrodes of the plurality are wet electrodes (with gel or solid gel). The support structure defines at least a partial relative position of the electrodes to one another. The support structure has a substrate made of polyurethane film material and a stiffening element detachably arranged on the substrate. The first side or surface of the support structure, on which the electrode arrangement is arranged, is, for example, opposite the stiffening element detachably arranged on the substrate.In other words, the electrode array, the support substrate, and the stiffening element detachably mounted on the support substrate are arranged, for example, in this order. The support structure with the stiffening element detachably mounted on the support substrate is dimensionally stable within a tolerance range, while the support structure without the stiffening element is dimensionally unstable or flexible. The support structure is designed to position at least part of the electrode array on the facial surface and behind the ear. The device is based on the same considerations as the devices described above. The device can be supplemented with all the features and functions described in relation to the devices described above.

[0050] According to one embodiment, the support substrate is reversibly rotatable multiple times and / or simultaneously reversibly deformable along two mutually perpendicular lateral directions in one thickness direction of the support structure, in order to create a dimensionally unstable support structure without the stiffening element detachably arranged on the support substrate. In other words, the support structure is dimensionally unstable without the stiffening element detachably arranged on the support substrate such that, within the scope of intended use, the support substrate can be rotated multiple times and / or simultaneously deformed along two mutually perpendicular lateral directions in one thickness direction of the support structure, within the scope of intended use. The deformations and rotations of the support substrate can occur without damage (cracks and fractures).It should be noted that at a point where the support structure is deformed or twisted, a normal vector orthogonal to a surface of the support structure facing away from the electrode array defines the thickness direction. The two mutually perpendicular lateral directions (i.e., a first lateral direction and a second lateral direction) span a plane perpendicular to the normal vector. Thus, the support substrate is designed, for example, to simultaneously deform or bend, from a deformation point, a surface of the support substrate lying in the first lateral direction and a surface of the support substrate lying in the second lateral direction, upwards or downwards, i.e., in the thickness direction. This type of deformation can occur without external force, following the force of gravity. If conductive traces are present in or on the support substrate, e.g.,With a curved profile, the deformation described above can occur under minimal force (< 1 N). The multiple twisting of the support substrate described above involves torsion around an axis along the first lateral direction, the second lateral direction, or any other direction within the plane defined by the two perpendicular lateral directions. Form instability or bending flexibility means that all the deformations and twists described above can occur without damaging the support substrate.

[0051] According to one embodiment, the carrier substrate is simultaneously deformable along two mutually perpendicular lateral directions with a bending radius in the thickness direction, ranging from 0.1 mm to 1 mm. The carrier substrate is so dimensionally unstable that it can adapt even to the smallest irregularities, such as skin folds. This dimensional instability allows the carrier structure to lie flat against the user's facial surface, reducing or even completely preventing lifting of the carrier structure, even in the presence of irregularities. This results in improved adhesion of the device to the user's facial surface, as a very large adhesive area of ​​the carrier structure can be brought into contact with the user's face. Furthermore, it increases wearing comfort and enables long-term measurements.

[0052] The form instability described above is achieved, for example, by a maximum thickness of 0.5 mm for the support substrate. This thickness corresponds to the expansion of the support substrate in the thickness direction.

[0053] The support structure is therefore dimensionally stable within a tolerance range without external force from the user, provided the detachable stiffening element is arranged on the support substrate. Furthermore, the support structure is deformable under external force from the user to change the distance between two adjacent electrodes and to adapt to facial and head structures across their entire surface, provided the stiffening element is detached from the support substrate.

[0054] Another embodiment relates to a device comprising a support structure and an electrode arrangement with a plurality of electrodes for measuring electrical signals on the facial surface of a user's head and behind the user's ear. The electrodes in the plurality of electrodes are wet electrodes (with gel or solid gel). The support structure defines at least a partial relative position of the electrodes to one another and has polyurethane foam as its substrate material. The support structure is dimensionally stable within a tolerance range without external force from the user and deformable under external force from the user to conform to the facial and head structures over their entire surface.The support structure is designed to be reversibly twisted multiple times under the external force applied by the user and / or to be reversibly deformed simultaneously along two mutually perpendicular lateral directions in one thickness direction of the support structure. The support structure is designed to position at least part of the electrode array on the facial surface and behind the ear. The device is based on the same principles as the devices described above. The device can be supplemented with all the features and functions described in relation to the devices described above.

[0055] In other words, under the external force applied by the user, the support structure can be twisted multiple times and / or deformed along two mutually perpendicular lateral directions in a thickness direction of the support structure, within the scope of its intended use. The deformations and twists of the support structure can occur without damage (cracks or fractures). It should be noted that at a point where the support structure is deformed or twisted, a normal vector, orthogonal to a surface of the support structure facing away from the electrode array, defines the thickness direction. The two mutually perpendicular lateral directions (i.e., a first lateral direction and a second lateral direction) span a plane perpendicular to the normal vector.Thus, the support structure is designed, for example, to be deformed by a user under external force in such a way that, viewed from a deformation point, a surface of the support structure lying in the first lateral direction and a surface lying in the second lateral direction can be simultaneously deformed or bent upwards or downwards, i.e., in the thickness direction. The multiple twisting of the support structure described above is a torsion about an axis along the first lateral direction, the second lateral direction, or another direction within the plane spanned by the two mutually perpendicular lateral directions, or a torsion about an axis located in a plane perpendicular to the thickness direction. All of the deformations and twistings described above can occur without damaging the support structure.

[0056] According to one embodiment, the support structure is simultaneously deformable along two mutually perpendicular lateral directions with a bending radius in the thickness direction, ranging from 0.1 mm to 1 mm. This deformability allows the support structure to lie flat against the user's facial surface, reducing or even completely preventing any lifting of the support structure, even on uneven surfaces. This results in improved adhesion of the device to the user's facial surface, as a very large adhesive area of ​​the support structure can be brought into contact with the user's face. Furthermore, it increases wearing comfort and enables long-term measurements.

[0057] The supporting structure has a thickness ranging from 0.5 mm to 2 mm in the thickness direction. A thickness within this range allows for dimensional stability without external force and dimensional instability under external force.

[0058] Another embodiment relates to a system with a device according to one of the embodiments described above and with an evaluation arrangement. The evaluation arrangement is designed to evaluate the electrical signals measured by the plurality of electrodes.

[0059] According to one embodiment, the evaluation arrangement is designed to provide information about the user's sleep architecture based on electrical signals; or to provide information about the user's epileptic behavior; or to indicate a neurological disorder in the user; or to provide cognitive-psychological information. Thus, the system according to the invention enables home or outpatient sleep monitoring, or home or outpatient monitoring of patients with epilepsy or suspected epilepsy, or of patients with other neurological disorders or suspected neurological disorders (e.g., depression, Alzheimer's disease), among other things, for deriving early indicators. Alternatively, the system is suitable for use in cognitive-psychological test series. The system is, for example,Designed to examine or determine a user's attention, vigilance, listening effort, cognitive load, cognitive processing ability, and / or sensory functionality, these cognitive-psychological tests can be conducted at home, in nursing homes, as well as in private practices or clinics, thanks to the system's specific design. A particular advantage of the system is the simple electrode installation, which saves time. The system according to the invention is also suitable for recording the aforementioned cognitive states in work situations, especially for safety-critical applications (e.g., train drivers, pilots, air traffic controllers, truck drivers, mining vehicles).Another possible application of the system is in neuropsychological research and in related research areas concerning cognitive states, but also in research areas concerning neurological disease symptoms in the waking state as well as in the sleeping state.

[0060] According to one embodiment, the system includes a hearing aid. The evaluation arrangement is designed to control the hearing aid based on the electrical signals.

[0061] According to one embodiment, the evaluation arrangement is configured to correlate the signals measured by the device with an envelope of an audio signal received by the hearing aid in order to control a beam modulator of the hearing aid. The inventors recognized that the electrical signals recorded by the device can indicate which audio signal the user's attention is focused on. The system can thus be configured to direct the beam modulator in the direction of the user's attention in order to emphasize the corresponding audio signal. The evaluation arrangement is configured, for example, to detect, based on the correlation, the user's attention to a time signal, i.e., the audio signal. The device is configured, for example, to measure or detect electrical signals based on muscle movements of the eye and / or on the eye body, which can function as a dipole. The evaluation device is, for example,The system is designed to generate an EOG (electrooscopical glottal stop) based on electrical signals, thereby deriving information about the user's gaze direction or blink rate. Gaze direction also indicates elements of attention, allowing the system to be configured to direct the beam shaper in the direction of the user's attention. This enables the hearing aid to selectively amplify audio signals originating from the user's attention. The result is a system that improves the sound quality received by the user.

[0062] According to one embodiment, the evaluation arrangement is designed to evaluate the signals measured by the device for predetermined signal characteristics in order to control the hearing aid in response to user signals, such as switching the hearing aid on and off, or regulating the volume, specific parameter sets, or signal amplification from a specific direction. Optionally, the evaluation arrangement includes a database in which the predetermined signal characteristics are stored. Control commands for the hearing aid can be linked to these predetermined signal characteristics. For example, the device can be designed to measure or detect electrical signals based on eye muscle movements and / or the eye body, which can act as a dipole. The evaluation arrangement can be configured to detect signal characteristics based on these signals, such as...These movements are linked to a predetermined eye movement, such as blinking or raising an eyebrow. This is based on the understanding that the signals measured by the device on the user's face or head can indicate characteristic facial movements. The system thus allows the hearing aid to be controlled automatically with facial movements, without having to press any buttons on the hearing aid itself. This simplifies the use of the hearing aid.

[0063] Another embodiment relates to a method for manufacturing the device according to one of the embodiments described above. The method includes, among other things, the step of providing a support structure, wherein the support structure is adapted to the facial surface of a user's head and wherein the support structure is dimensionally stable within a tolerance range without external force from the user and is deformable under external force from the user in order to change the distance between two adjacent electrodes and / or to adapt to facial and head structures over their entire surface. Dimensional stability can be achieved, for example, by using a material such as polyurethane foam and a specific thickness, e.g., in the range of 0.5 mm to 2 mm, for the support structure.Alternatively, the support structure can be composed of a support substrate and a detachable stiffening element. The support substrate can, for example, comprise a carrier material, such as polyurethane, polymer, and / or silicone. The detachable stiffening element is designed, for example, to stabilize the shape of the support structure. According to one embodiment, at least one detachable stiffening element can be arranged locally on the support substrate. Alternatively, the entire support substrate can be covered with the stiffening element. A further step of the method involves attaching an electrode arrangement to the support structure. The electrode arrangement comprises a plurality of electrodes for measuring electrical signals on the facial surface of a user's head and / or for measuring electrical signals behind the user's ear.The support structure defines at least a partial relative position of the electrodes to each other, wherein the support structure is designed to position at least part of the electrode arrangement on the facial surface and / or behind the user's ear.

[0064] Another embodiment relates to a method for using the device according to one of the embodiments described above. The method includes, among other things, the steps of the user or another person applying the device to the facial surface of a user's head and monitoring the user based on the electrical signals measured by the plurality of electrodes. A particular advantage of the present invention is that it can be applied by the user themselves.

[0065] According to one embodiment, the method includes monitoring the user's sleep behavior based on the measured electrical signals; or monitoring cognitive behavior based on the measured electrical signals.

[0066] According to one embodiment, applying the device to the user's face includes the steps of locating an upper cheekbone and attaching a first electrode to it; attaching a second electrode in front of the tragus of one of the user's ears; attaching a third electrode to the forehead vertically above a nasion in a region 1-3 cm above the eyebrow line; and attaching a fourth electrode behind the ear. It is particularly advantageous to attach the first electrode to the face in a first step and the second electrode in a second step. This is based on the understanding that the cheekbone and the point in front of the tragus are very prominent landmarks on the face and therefore very easy for a user to locate.This allows the first and second electrodes to be placed very precisely on the facial surface. The user is guided in placing the remaining electrodes of the device's multiple electrode array by the shape of the device's support structure, as this shape is designed, for example, to define the position of the remaining electrodes relative to the first and second electrodes on the facial surface. Character description

[0067] All examples explained herein, which do not exhibit all features, or equivalents thereof, of any of the independent claims, serve to facilitate understanding of the invention. Exemplary embodiments according to the present invention are explained in more detail below with reference to the accompanying figures. With regard to the schematic figures shown, it should be noted that the functional blocks depicted are to be understood both as elements or features of the device according to the invention and as corresponding process steps of the method according to the invention, and corresponding process steps of the method according to the invention can also be derived from them. The figures show: Fig. 1a a schematic representation of a device according to an embodiment of the present invention; Fig. 1b a schematic representation of the device on a user's head according to an embodiment of the present invention; Fig. 2 an n=1 rotation; Fig. 3a a schematic representation of a device with a stiffening element according to an embodiment of the present invention; Fig. 3b the dimensional stability of a connecting web of a support structure with or without a stiffening element of a device according to an embodiment of the present invention; Fig. 4a a schematic representation of a device with a connecting web to a chin area of ​​a user of the device according to an embodiment of the present invention; Fig.Fig. 4a: Schematic representation of a device with a support structure having protrusions at certain electrode positions, according to an embodiment of the present invention; Fig. 5a: Schematic representation of a device on a user's head in a side view, according to an embodiment of the present invention; Fig. 5b: Schematic representation of a device on a user's head in a view from the back of the user's head, according to an embodiment of the present invention; Fig. 6a: Schematic representation of linear combinations of electrode channels for an EEG, according to an embodiment of the present invention; Fig. 6b: Schematic representation of linear combinations of electrode channels for an EOG and EMG, according to an embodiment of the present invention; Fig.7. A schematic representation of a device with cable connections, according to an embodiment of the present invention; Fig. 8a. A schematic representation of an electrode integrated into a support structure of the device, according to an embodiment of the present invention; Fig. 8b. A schematic representation of an electrode with a gel lens integrated into a support structure of the device, according to an embodiment of the present invention; Fig. 9a. A schematic representation of a device with a signal amplifier in a headband, according to an embodiment of the present invention; Fig. 9b. A schematic representation of a signal amplifier in a neckband, according to an embodiment of the present invention; Fig. 9c. A schematic representation of a device with a signal amplifier behind or below a user's ear, according to an embodiment of the present invention; Fig.Fig. 9a schematic representation of a device with a signal amplifier on a user's shoulder or chest, according to an embodiment of the present invention; Fig. 9e a schematic representation of the position of a signal amplifier relative to a muscle arrangement in a neck region of a user, according to an embodiment of the present invention; Fig. 10 a block diagram of a method for using a device according to the invention; Fig. 11 a block diagram of a system with an amplifier and a device according to the invention; Fig. 12 a schematic representation of a system with an evaluation arrangement and a device according to the invention; Fig. 13 a block diagram of a method for manufacturing a device according to the invention; Fig. 14 a conventional electrode placement in polysomnography; Fig.Fig. 15 A schematic representation of a device with a signal output shown on the support structure according to an embodiment of the present invention; Fig. 16 A schematic representation of a device with an electrode arrangement that is positioned behind a user's ear. Detailed description of the embodiments according to the figures

[0068] Before exemplary embodiments of the present invention are explained in detail below with reference to the drawings, it should be noted that identical, functionally equivalent or equivalent elements, objects and / or structures in the different figures are provided with the same or similar reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0069] Fig. 1ashows a schematic representation of a device 100 according to an embodiment of the present invention and Fig. 1b The device shows 100 on a user's head 200 210.

[0070] The device 100 has an electrode arrangement 110 with a plurality of electrodes 110 1 to 110 5 for measuring electrical signals on a facial surface 220 of the head 200 of the user 210 and behind an ear 230 of the user 210. According to Fig. 1a and Fig. 1b A first electrode 110 1, a second electrode 110 2, and a third electrode 110 3 are configured to measure electrical signals on a facial surface 220 of the head 200 of the user 210. A fourth electrode 110 4 and a fifth electrode 110 5 are configured to measure electrical signals behind the ear 230 of the user 210. However, the device is not designed for the applications described in the Figures 1a and 1b The number and arrangement of electrodes shown is limited to 110 1 to 110 5.

[0071] Furthermore, the device 100 has a support structure 120. The plurality of electrodes 110 1 to 110 5 are arranged, for example, at a corresponding plurality of electrode positions on the support structure 120. The plurality of electrodes 110 1 to 110 5 of the electrode arrangement 110 are connected to one another, for example, via the support structure 120, wherein the support structure 120 at least partially defines a relative position of the electrodes 110 1 to 110 5 to one another. The support structure 120 has branching connecting webs that connect the electrodes 110 1 to 110 5 to one another and at least partially define the relative position of the electrodes 110 1 to 110 5 to one another, since the positions of the plurality of electrodes 110 1 to 110 5 are limited to positions on the connecting webs. The shape and length of a connecting web between two adjacent electrodes define, for example, the shape of the electrodes. B. the relative position of the two adjacent electrodes to each other.The shape and length of a connecting bridge between two adjacent electrodes defines, for example, the positions of the two electrodes on the user's head 200. The shape follows, for example, a human facial shape or structure. The shape of the support structure defines, for example, a position for each electrode in the multitude of electrodes on the user's head 200, i.e., on the facial surface 220 and behind the ear 230.

[0072] The support structure 120 is designed to position at least a first part of the electrode arrangement, e.g., electrodes 1101 to 1103, on the facial surface 220 and a second part of the electrode arrangement, e.g., electrodes 1104 and 1105, behind the ear 230. The support structure 120 is designed, for example, by its special shape, to position the multiple electrodes 1101 to 1105, since, for example, the shape and length of the branching connecting bridges follow a facial or head structure, and thus the branching connecting bridges define the positions of electrodes 1101 to 1105 on the facial surface 220 of the user's head 200 and behind the user's ear 230.

[0073] The support structure 120 is dimensionally stable within a tolerance range without external force from the user 210 and deformable under external force from the user 210. Dimensionally stable within a tolerance range means, for example, that the support structure can only bend slightly under the influence of gravity. This prevents the form from collapsing when the user places it against the head 200. The support structure is designed, for example, to allow a maximum bend of 6 cm over a length of 10 cm without external force from the user 210. For this purpose, the support structure can, for example, have a support structure designed to counteract deformation. This support structure can be designed as a removable stiffening element so that it can be removed after the support structure has been applied to the head surface.Alternatively, dimensional stability can also be achieved through the thickness of the support structure. The thicker the support structure, the more dimensionally stable it is. A thickness of 1 mm, for example, provides sufficient dimensional stability. At lower thicknesses, dimensional stability can be achieved through the support structure. In addition to dimensional stability, the support structure 120 exhibits a certain degree of extensibility or elasticity, allowing it to be deformed under external force applied by the user 210. The user can, for example, stretch or bend the support structure to change the distance between two adjacent electrodes and / or to adapt it to facial and head structures across their entire surface. This comprehensive adaptation gives the support structure a large contact area on the head surface, allowing it to be more robustly fixed to the user's head.The support structure is therefore designed to remain stably in place on the skin for several hours, an entire night, a full day, or even several days. For example, the support structure is designed to increase the distance between two adjacent electrodes under the external force exerted by the user 210 by 5% to 10% or 5% to 20%. This is typically utilized primarily to reach the forehead electrode, e.g., the third electrode 110 2. However, the material's flexibility is advantageous for allowing minor adjustments to its placement above and behind the ear 230 and for ensuring a high level of wearing comfort during facial movement.

[0074] For example, when choosing materials for the overall structure, it is important that (a) the carrier structure 120, which adheres to the skin, is easily deformable (flexible and / or partially stretchable) under the influence of the user 210 in order to adapt well to facial structures (e.g., curves) for a flat and thus robust bond and to differences in facial proportions in order to achieve the desired electrode positions; and that (b) the carrier structure 120 remains dimensionally stable for the bonding process without the influence of the user, so that the arms of the grid (e.g., the network of branching connecting struts of the carrier structure) do not unintentionally stick to facial features, fingers, or to each other during application if they droop due to very high flexibility.

[0075] The support structure 120, which ultimately adheres to the skin, is therefore characterized by extensibility and / or flexural rigidity, i.e., shape instability or lability: The support structure is, for example, so deformable that a connecting web of the support structure 120 can be twisted into itself several times without the connecting web tearing. Fig. 2Such a twisting process is shown using paper with n=1 rotations. This type of deformability can be achieved, for example, if the support structure is made of polyurethane, polymer, and / or silicone. Electrical connections, such as the multitude of electrodes with a signal output of the device, can also influence the deformability of the support structure. To maintain the extensibility of the overall structure, conductor tracks or cable connections are designed, for example, to provide additional length in the form of waves or loops. If the support structure uses polyurethane as its substrate, this can be in the form of polyurethane film material with conductor tracks arranged in a looped pattern, or in the form of polyurethane foam with cable connections on top.In the case of polyurethane film material, the support structure is designed, for example, to allow or permit an elongation in a range of 5% to 10%, and in the case of polyurethane foam, the support structure is designed, for example, to allow or permit an elongation in a range of 5% to 20%.

[0076] A thin polyurethane film material (e.g., with a thickness between 0.1 mm and 0.5 mm) can be twisted multiple times as a strip without tearing. The carrier material proposed here as a thin film should withstand more than n = 1 twists without tearing or otherwise failing. Its flexibility means it can be easily deformed in any direction (with minimal finger pressure, i.e., under external force from the user) and thus provides a high level of wearing comfort, as the edges of the carrier structure easily conform to the head surface. Furthermore, it exhibits an elongation of up to 5% or up to 10%, depending, for example, on the choice of conductor geometry or cable routing along the carrier structure.The high degree of flexural flexibility may necessitate a removable stiffening element on the side of the support structure facing away from the skin to provide the necessary rigidity for the application process. This stiffening element can, for example, be integrated into the support structure itself. After or during application, this additional stiffening element can be removed to allow the thin profile and full elasticity to be utilized for optimal wearing comfort.

[0077] Polyurethane foam with a thickness of up to 1mm does not have as high a flexibility as the thin polyurethane film material, but it is highly elastic (up to 20% of the length) and is also very easy to deform (little pressure from the fingers) and thus also meets the requirements stated here.

[0078] In general, a material within the meaning of this application is considered flexible if it is deformable or bendable in all directions and can be twisted without being damaged, e.g., without tearing. Flexibility can be understood, for example, if a film or layer of the material bends under the influence of gravity alone, i.e., without any further external force or with only a slight external force (e.g., F ≤ 1 N). Flexibility allows for the material to conform to irregularities in facial and head structures. If the structure (e.g., the support structure with polyurethane film with a maximum thickness of 0.1 mm, 0.3 mm, or 0.5 mm, or the support structure with polyurethane foam with a thickness in the range of 0.5 mm to 2 mm) is applied to a radial protrusion (assumed here to be a cylinder) with a diameter of, for example, 0.Laid down 5 cm and 1 cm high, the support material can simultaneously come to rest flat on the circular surface and at four points on the cylindrical surface, either under its own weight due to gravity or through the application of a small force (< 1 N). Two of these areas on the cylindrical surface are opposite each other, and the lines connecting the opposite surfaces are perpendicular to each other, without damaging the support structure (tearing or breaking). The structure follows the 90° angle from the circular surface to the cylindrical surface with a tight radius of no more than 1 mm. If a layer or structure is flexible, it will conform to all irregularities. Flexible structures and layers are characterized, for example, by a low modulus of elasticity, low tensile stiffness, and therefore large deformations even under small force and moment loads. Flexibility can be described, for example, by...A structure can be understood as one that is deformable along two mutually perpendicular lateral directions in a thickness direction of the structure without being damaged, and / or one that is multiple times twistable into itself without being damaged, i.e., when, for example, a torsional moment acts on the structure to twist it multiple times around an axis perpendicular to the thickness direction.

[0079] The overall structure should remain dimensionally stable without any intervention from the user 210, so that the device 100 can be easily applied by the user 210 themselves. If the support structure, for example, comprises the thin polyurethane film material, the support structure optionally also comprises further materials or elements designed to stabilize the support structure and thus ensure its dimensional stability. These reinforcing materials or elements are, for example, detachably attached to the thin polyurethane film material, so that the support structure is dimensionally stable when it comprises both the polyurethane film material and a reinforcing material or element, and is flexible when the reinforcing material or element is detached from the polyurethane film material.In contrast, polyurethane foam does not require a supporting structure, as the material itself already possesses dimensional stability while remaining flexible under user influence. Optionally, however, the support structure can be further stabilized even when using polyurethane foam as a substrate.

[0080] The dimensional stability of the support structure in the absence of any external force applied by the user 210 can be achieved in various ways: According to one embodiment, the support structure 120 has an adhesive material for fixing the plurality of electrodes 1101 to 1105 and the support structure 120 to the facial surface and behind the ear 230. The adhesive material is, for example, covered by a removable protective layer. The protective layer is, for example, a film or paper material. The protective layer has, for example, a plurality of protective layer sections that can be detached independently from the support structure 120. The film or paper material covering the adhesive layer or the adhesive material can provide additional stability, since the film or paper material is detached in individual sections when the support structure 120 is applied to the head 200.in individual sections of the protective layer, which can be peeled off, thus maintaining stability during the process.

[0081] Additionally or alternatively, a support structure, e.g., in the form of a film (e.g., made of polyimide, polyester, polyethylene, or FR4 material), paper, or polyurethane foam, can be applied to the side of the support structure 120 facing away from the skin. The support structure can also be considered a stiffening element 122. As shown in Fig. 3aAs shown, the support structure 120 can have a detachable stiffening element 122 on one side facing away from the electrode arrangement 110. This stiffening element is designed to stiffen the support structure 120, at least locally. For example, the stiffening element 122 is only present during the application process of the support structure 120 to the head surface, i.e., on the facial surface 220 and behind the ear 230. After or during the application of the support structure 120, which, as described above, can also be done in stages, the stiffening element 122 can be removed from the support structure 120. This is particularly relevant for thin support materials with very high flexural rigidity, as the stiffening element 122 counteracts the flexural rigidity of the support material and thus significantly facilitates the user's independent application of the device 100 to the head surface 210.The fact that the stiffening element 122 can be detached from the support structure 120 after it has been attached to the user's head 210 increases the user's comfort. This is because the support material is deformable without the stiffening element 122 and is therefore designed to conform to facial movements, such as muscle or jaw movements. The adhesive bond between the stiffening element 122 and the support structure 120 is designed, for example, to leave no adhesive residue when the stiffening element is removed.

[0082] In Fig. 3a A device 100 is shown which can have all the features and functionalities that are also associated with the device from Fig. 1a and 1b have been described. Fig. 3aFigure 1 shows a stiffening element 122 arranged on a branching connecting web of the support structure 120. The connecting web is designed, for example, to connect the first electrode 1101 and the second electrode 1102 to the third electrode 1103 on one side and to the fourth electrode 1104 and the fifth electrode 1105 on the other. The connecting web branches, with a first part 1241 of the connecting web leading to the third electrode 1103 and a second part 1242 of the connecting web leading to the fourth electrode 1104 and the fifth electrode 1105. The stiffening element on the connecting web maintains the shape of the connection between the electrodes.This is particularly important for positioning the support structure 120 on the head surface, since the shape of the connecting bridge at least partially defines and shapes the relative position of the electrodes to each other in order to position the electrodes on the head surface in such a way that the electrodes occupy predetermined positions on the head surface. As an alternative to the single stiffening element 122, the device 100 can also have several stiffening elements or a single stiffening element 122 that covers the entire surface of the support structure 120 (i.e., the surface on the side facing away from the electrode arrangement 110).

[0083] Another possibility is to make the support structure thicker. If the support structure 120 uses, for example, polyurethane foam material as its substrate, this can be made with a thickness ranging from 0.5 mm to 2 mm to achieve the necessary dimensional stability of the support structure without an additional stiffening element 122. However, even in this case, the support structure 120 can optionally include an additional stiffening element.

[0084] Polyurethanes are particularly suitable as materials for the support structure 120, either as a thin support film with an additional, temporary support structure applied accordingly, i.e., with the stiffening element 122, or as polyurethane foam for thicknesses in the range of 0.5 mm to 2 mm. Preferably, the conductor tracks are applied directly to the polyurethane film or the conductor tracks (apart from the electrode surfaces) are incorporated into a polyurethane sandwich construction (see the Figures 8a and 8b (with accompanying description), the polyurethane foam version can serve as a support structure for conventional fixed gel electrodes with cables (see Fig. 7 (with accompanying description).

[0085] The dimensional stability of the grid structure, i.e., the support structure 120, with corresponding support structure, i.e., with the stiffening element 122, is described in Fig. 3b This is exemplified by how an arm 124, i.e., a connecting bridge, of length 10 cm (see 125 1 ) tilts downwards, following the force of gravity 300, when the arm 124 is oriented horizontally (perpendicular to the force of gravity 300). The arm 124 does not tilt further than about 6 cm over this length (see 125 2 ). Applying this, for example, to the connecting bridge 124 1 of the Fig. 3aIf the connecting web 124 1, which has a length of approximately 7 cm between points A and B (see 125 1), does not tilt further than approximately 4 cm (see 125 2). Generally, a connecting web of the support structure 125 is designed to be dimensionally stable within a tolerance range without external force being applied by the user 210. A horizontally oriented connecting web of the support structure 120, for example, is designed to tilt by a maximum of 60% of its length under the influence of gravity 300, with a length of up to a maximum of 12 cm. The limitation of the tilt or bending can be achieved, among other things, by means of one of the features discussed above, such as an adhesive protective film, a stiffening element 122, or a specific thickness of the support structure. During installation, the grid, i.e. the support structure, is held upright, so that the arm 124 tilts even less, as it is at a different angle to gravity 300. Fig. 3b This thus demonstrates, by way of example, the stiffness of the support structure 120 with support structure or an effect of the support structure on the dimensional stability of the support structure 120.

[0086] The Figures 4a and 4b show a further embodiment of the device 100 according to the invention. Optionally, the device can have features and functionalities as described in connection with exemplary embodiments of the Figures 1a to 3b have been described, exhibit. It is also possible that exemplary embodiments from the Figures 1b to 3b exhibit features or functionalities as described below. The device in Fig. 4a differs from the device in Fig. 1aThe only difference is that more electrodes are arranged on the support structure 120, and the support structure 120 further comprises a connecting bridge that links the first electrode 110 1 and the second electrode 110 2 to electrodes whose positions can be assigned on the user's chin. The device in Fig. 4b differs from the device in Fig. 4a only in the number and diameter of the electrodes and in bulges of the support structure at certain electrode positions.

[0087] As in Fig. 4a The figure shows the shape of the support structure 120, on which the multitude of electrodes 110 1 to 110 10 (or 110 1 to 110 9) are mounted. Fig. 4b ) is a special feature of the present invention. The shape is based on structures on a user's head 200 210. In the Figures 5a and 5b The device 100 is an example. Fig. 4a and Fig. 4barranged on the head 200 of the user 210. Fig. 5a shows a placement of the device 100 in a side view of the head 200 of the user 210 and Fig. 5b shows a placement of the device 100 in a view from the back of the user's head 210.

[0088] The support structure includes, for example, a first connecting web 123 that connects the first electrode 110 1 and the second electrode 110 2, with the first electrode 110 1 being arranged at a first end of the first connecting web 123 and the second electrode 110 2 being arranged at a second end of the first connecting web 123. The first connecting web 123 has, for example, a coiled or looped shape, such as a wave-like profile. The coiled shape of the connecting web between the first electrode 110 1 and the second electrode 110 2 creates a very dimensionally stable connection between the two electrodes. This is particularly advantageous because the first electrode and / or the second electrode serves as a reference for the positions of the remaining electrodes of the plurality of electrodes 110 1 to 110 10 (or 110 1 to 110 9 in Fig. 4b) and thus ensures that the user can independently and very precisely place these two electrodes on the facial surface 220. Furthermore, the special shape of the first connecting bridge 123 increases wearing comfort. This is because the position of the first electrode 110 1 on the facial surface 220 corresponds, for example, to a position on a cheekbone, i.e., on a first prominent point of the facial surface, and the position of the second electrode 110 2 on the facial surface 220 corresponds, for example, to a position in front of a tragus 232 of the ear 230, i.e., on a second prominent point of the facial surface. Due to the curved shape of the first connecting bridge 123 and the deformability or elasticity of the carrier material of the support structure 120, it is designed to follow facial movements in the area between the first electrode 110 1 and the second electrode 110 2.This increases wearing comfort.

[0089] According to one embodiment, the support structure 120 has, for example, a branching second connecting web 124, which connects the first electrode 110 1 and the second electrode 110 2 to a third electrode 110 3 on one side and to a fourth electrode 110 4 on the other (the fourth electrode can also be one of the electrodes 110 5 to 110 7 from Fig. 4a be or the electrode 110 5 or 110 6 from Fig. 4b his), wherein the second connecting bridge 124 branches at a junction 124 3 into a first part 124 1 and into a second part 124 2.

[0090] The first part 124 1 of the second connecting web 124 is designed to connect the first electrode 110 1 and the second electrode 110 2 to the third electrode 110 3. The second connecting web 124 extends, for example, from a midpoint of the first connecting web 123, via the first part 124 1, to the third electrode 110 3, with the third electrode 110 3 being located at one end of the first part 124 1. The second connecting web 124 runs from a midpoint of the first connecting web 123, via the first part 124 1, in an arc or curved shape. The second connecting web, together with the first part 124 1, follows the curve of the first connecting web 123. B. a shape of an eye or an eyebrow 240. If the carrier structure 120 is arranged on a head surface of the user, the second connecting bridge 124 runs above along the eyebrow 240 to the third electrode 110 3. The position of the third electrode 110 3 corresponds on the facial surface 220 e.g.a position vertically above a nasion 250 of the user 210, i.e., a third prominent point on the facial surface 220. In other words, the support structure has a connecting bridge, namely the second connecting bridge 124, which connects a first electrode position, which is associated with the first electrode 110 1 of the plurality of electrodes, and / or a second electrode position, which is associated with the second electrode 110 2 of the plurality of electrodes, on the one hand, with a third electrode position, which is associated with the third electrode 110 3 of the plurality of electrodes, on the other hand, and wherein the third electrode position, within a tolerance range of 1 to 2 cm determined by the support structure 120, coincides on both sides next to a position on a forehead of the facial surface in a range of 1 cm to 3 cm above the eyebrow line vertically above a nasion 250 of the user 210.

[0091] The second part 124 2 of the second connecting bridge 124 is designed to connect the first electrode 110 1 and the second electrode 110 2 to the fourth electrode 110 4. Optionally, further electrodes (e.g., electrodes 110 5 to 110 7) can be attached to the second part 124 2 of the second connecting bridge 124. Fig. 4a or electrodes 110 5 and 110 6 from Fig. 4b) the multitude of electrodes may be arranged, which is why the second part 124 2 of the second connecting bridge 124 may further be designed to connect the first electrode 110 1 and the second electrode 110 2 to the other electrodes. The second part 124 2 of the second connecting bridge 124 extends, for example, from the branch point 124 3 in the opposite direction to the first part 124 1 of the second connecting bridge 124. At one end of the second part 124 2, the second connecting bridge 124 is, for example, curved or runs in an arc. The arc of the second connecting bridge runs, for example, around the position of the second electrode 110 2. If the support structure 120 is arranged on the head surface of the user 210, the arc of the second connecting bridge 124 runs, for example, around the position of the second electrode 110 2. B. along the shape of the ear 230. The fourth electrode 110 4 as well as possible further electrodes of the plurality of electrodes are preferably arranged on the arc of the second connecting bridge 124.The position of the fourth electrode 110 4 corresponds on the head surface, for example, to a position behind the ear 230 of the user 210. Optionally, the position of the fourth electrode corresponds to the position of the mastoid (see point D in . Fig. 5b), i.e., a fourth prominent point on the head surface. In other words, the support structure has a connecting bridge, namely the second connecting bridge 124, which at least partially connects the first electrode position and / or the second electrode position, on the one hand, with a fourth electrode position, which is associated with the fourth electrode 110 4 of the plurality of electrodes, and wherein the fourth electrode position corresponds, within a tolerance range determined by the support structure 120, to a position behind the ear 230 on a mastoid of the user 210. The second part 124 2 of the second connecting bridge 124 leads, for example, above the ear 230 of the user 210 to the arc that follows the shape of the ear 230 behind the ear 230.

[0092] According to one embodiment, an electrode (e.g. 110 10 in Fig. 4a or 110 9 in Fig. 4bThe multiple electrodes are arranged in a region of the branch point 124 3 of the second connecting bridge 124. In this way, the first electrode 110 1, the third electrode 110 3, and the electrode 110 10 / 110 9 form, for example, a triangle in the region of the branch point 124 3 of the second connecting bridge 124. With a tolerance range of ±5°, the triangle has a right angle at electrode 110 10 / 110 9 in the region of the branch point 124 3 of the second connecting bridge 124. Due to the specific arrangement of these three electrodes, eye movement can be detected very precisely with the device 100.

[0093] Optionally, the support structure 120 also has a third connecting web 126, which connects the first electrode 110 1 and the second electrode 110 2 with a fifth electrode (e.g. 110 9 in Fig. 4a or 110 3 in Fig. 4b) connects. The third connecting bridge 126 extends, for example, from approximately the middle of the first connecting bridge 123 in the opposite direction to the second connecting bridge 124, with the fifth electrode 110 9 / 110 8 being located at one end of the third connecting bridge 126. The third connecting bridge 126 has, for example, a curved shape. If the support structure 120 is located on a facial surface 220 of the user 210, the third connecting bridge 126 extends along a jaw 260 to the fifth electrode 110 9 / 110 8. The position of the fifth electrode 110 9 / 110 8 on the facial surface 220 corresponds to the position of the jaw 260. B. a position on or at the chin 270 of the user 210, i.e. a fifth prominent point on the facial surface 220. Optionally, further electrodes of the plurality of electrodes can be arranged on the third connecting bridge 126.In other words, the support structure 120 has a connecting bridge, namely the third connecting bridge 126, which connects the first electrode position and / or the second electrode position on the one hand with a fifth electrode position, which is assigned to the fifth electrode 110 9 / 110 8 of the plurality of electrodes, on the other hand at least partially, and wherein the fifth electrode position corresponds within a tolerance range determined by the support structure 120 to a position on the chin 270 of the facial surface 220 of the user 210.

[0094] The connecting bridges of the support structure 120 have a bridge width that corresponds at most to three, two, or 1.5 times the electrode diameter of one electrode of the plurality of electrodes. Transition areas, i.e., the connecting bridges, can be designed as a "slim waist" to achieve optimal flexibility for adapting to different head shapes and sizes.

[0095] The first electrode 1101 and / or the second electrode 1102 define, for example, a reference position, and the remaining electrodes of the plurality of electrodes are arranged on the support structure 120 relative to the reference position. According to one embodiment, a first electrode position corresponding to the position of the first electrode 1101 on the support structure 120 can serve as the reference position, or a second electrode position corresponding to the position of the second electrode 1102 on the support structure 120 can serve as the reference position. Alternatively, it is also possible for the remaining electrodes of the plurality of electrodes to be arranged relative to the first and second electrode positions on the support structure 120. In this case, for example, a position midway between the two electrode positions could serve as the reference position.As mentioned above, the positions of the first and second electrodes serve particularly well as reference positions, as these can be positioned very precisely by the user on their head surface. Based on these two positions, the carrier structure can, for example, use the second connecting bridge and the optional third connecting bridge to very precisely define the positions of the remaining electrodes of the multitude of electrodes on the head surface, i.e., on the facial surface 220 and behind the ear 230.

[0096] According to one embodiment, the carrier structure 120 has an adhesive material for fixing the plurality of electrodes and the carrier structure 120 to the head surface, i.e., to the facial surface 220 and behind the ear 230. The adhesive material is applied, for example, to the side of the carrier structure 120 on which the electrode array is also arranged. The adhesive material is thus located on the side of the carrier structure facing the user's skin. Optionally, the electrodes of the plurality of electrodes can additionally or alternatively have an adhesive electrolyte gel designed to fix the plurality of electrodes to the head surface and reduce impedance. The adhesive material and / or the adhesive electrolyte gel are at least partially covered with a protective film.

[0097] The protective film can, for example, be divided into a plurality of protective film sections, which can be detached independently from the support structure 120 and / or the plurality of electrodes. A first protective film section of the plurality of protective film sections covers, for example, a first subset of the plurality of electrodes and the support structure 120, and a second protective film section of the plurality of protective film sections covers, for example, a disjoint second subset of the plurality of electrodes and the support structure 120. The first protective film section covers, for example, the first connecting bridge 123, which has the first electrode 1101 and the second electrode 1102. The second protective film section covers, for example, the second connecting bridge 124, which has, among other things, the third electrode 1103 and the fourth electrode 1104, and optionally further electrodes of the plurality of electrodes.Optionally, the second connecting web 124 can also be covered by two different protective film sections. One protective film section (e.g., the second protective film section) then covers, for example, the part of the second connecting web 124 that is connected to the first connecting web 123 and also includes the first part 124 1 of the second connecting web 124, and another protective film section (e.g., a third protective film section) then covers, for example, only the second part 124 2 of the second connecting web. An optional further protective film section covers, for example, the third connecting web 126, which includes at least the fifth electrode 110 9 / 110 8 of the plurality of electrodes.This division of the protective film sections is particularly advantageous because the protective film section can always be removed from the area that is to be applied next to the user's head surface 210. This makes the device easy to handle during application, as the adhesive material is only exposed for a small area at any given time. Furthermore, the specific selection of the first protective film section allows the user to initially concentrate fully on positioning the first and second electrodes, enabling very precise placement. The positions of the remaining electrodes of the multiple electrodes on the head surface are then determined by the shape of the support structure 120, in particular by the shape of the second connecting bridge 124 and the optional third connecting bridge 126.Thus, the majority of protective film sections leads to a high accuracy in the positioning of the device 100 and also enables the user 210 to independently position and fix it to the head surface of the user 210.

[0098] For positioning and fixing the device 100 to the user's head surface 210, further advantages include extensions 130 1 to 130 7 or noses, such as those found, for example, in Fig. 4bThe support structure 120 has, for example, at a position where an electrode of the electrode arrangement 110 is located, at least one extension 130 1 to 130 7. As shown, for example, for the fourth electrode 110 4, the support structure 120 can also have several extensions, such as two extensions, at a position where an electrode of the electrode arrangement 110 is located. An adhesive material is, for example, arranged on the extensions, which improves the fixation of the electrodes, at whose position the support structure has at least one extension 130 1 to 130 7, to the facial surface.

[0099] The positions of the electrodes in electrode array 110 were selected such that, on the one hand, only areas of skin exposed to hair are used for the application of, for example, an adhesive substrate, and on the other hand, signal components of conventionally used PSG electrodes are derived from linear combinations of the electrode signals. The procedure for generating linear combinations is demonstrated in [Da Silva Souto, CF, Pätzold, W., Wolf, I., Paul, M., Matthiesen, I., Bleichner, MG, & Debener, S. (2021). "Flexprinted ear-EEG sensors for adequate sleep staging at home."; Frontiers in Digital Health, 3, 66] based on the flexible electrode solution cEEGrid.

[0100] As in the Figures 6a and 6bAs shown, the form of the support structure 120 is designed, for example, to position the multitude of electrodes at a corresponding multitude of positions on the facial surface; the multitude of positions for capturing the electrical signals on the facial surface is configured for at least one linear combination of the electrical signals to map signals from a predetermined head region of the user. Using the linear combinations, an EEG, an EOG, and an EMG can be recorded, for example, for a head region of the user. Signals from an ECG are also recorded in the electrode channels and can be extracted using signal processing methods, e.g., independent component analysis (ICA). The linear combinations of the electrode channels can be used, for example, to highlight specific signal components.The electrode channels are designated Ri for i=1 to 11 and are referenced to the electrode REF.

[0101] Fig. 6aThis diagram illustrates specific brain regions for which signals can be mapped by forming specific linear combinations. The electroencephalogram (EEG) is set up, for example, for a frontal region, a central region, a parietal region, and an occipital region. For the frontal region, for example, the signals from electrode channels 1 and 4 are read directly, and the signals from electrode channels 2 and 4 are combined via a linear combination (R2-R4). For the central region, for example, linear combinations are formed from the signals of electrode channels 1, 4, 5, and 7 (e.g., a first linear combination with (R2+R5) / 2-R4 and a second linear combination with R5-R7). For the parietal region, for example, a linear combination can be formed from the signals of electrode channels 4 and 5 (R5-R4), and for the occipital region, for example, a linear combination of the signals from electrode channels 2 and 4 is used. B. Linear combinations of the signals from electrode channels 4, 6 and 7 (e.g.A first linear combination with R6-R4 and a second linear combination with R7-R7) were formed. This allows relevant sleep parameters to be recorded in the EEG, despite limited electrode placement.

[0102] Fig. 6b This shows that, in addition, an electrooculogram (EOG) can be recorded (vertical (R2-R3), horizontal (R2-R1), and diagonal (R1-R3)) and an electromyogram (EMG), particularly in the chin area (R10-R11). The electrodes of the electrode array, which are arranged around the user's eye, are positioned, for example, within a tolerance range of ±5° in a right-angled triangle. Eye movement is thus recorded diagonally via electrodes 1 and 3, horizontally via electrodes 1 and 2, and vertically via electrodes 3 and 2. Electrodes 10 and 11 are used to record the EMG.

[0103] Further applications for these electrode positions are conceivable; however, the arm to the chin electrodes can also be omitted from the design. A possible reduction to only arm D (designation from Figure 5a and Figure 5b ) behind the ear and C on the forehead can pre-place and possible rotation via electrode 2 ( Figures 6a and 6b ) take place.

[0104] The signals also contain information such as that from an electrocardiogram. This information can be extracted using signal processing techniques, such as Independent Component Analysis (ICA).

[0105] According to one embodiment, the user can wear a first support structure according to the invention with an electrode arrangement on one side of the face and a second support structure according to the invention with an electrode arrangement on the opposite side of the face. This allows the signals from the two electrode arrangements to be combined, which permits further linear combinations that run centrally through the head.

[0106] In the devices 100 described herein, the numerous electrodes are wet electrodes. These wet electrodes, which can be applied by an untrained person, significantly expand the range of applications for wet electrodes for recording electrophysiological signals, particularly EEG, but also EOG and EMG, across a broad spectrum of uses. Individuals can thus regularly perform high-quality data collection at home without the presence of a trained professional. Thanks to their comfortable fit and discreet placement, long-term measurements for biosignal monitoring are also feasible in everyday life. With device 100, a configuration of wet electrodes is arranged in a grid structure, i.e., on the carrier structure, in such a way that they can be applied by an untrained person and reliably assume specific electrode positions on the face and behind the ear with minimal positional variation.

[0107] The design of the electrode grid, i.e., the support structure 120 with the electrode arrangement 110, was based on, among other things, the following requirements: It should be easy to self-apply, meaning that untrained individuals can easily apply the grid themselves using a manual or similar. It should fit various head shapes, meaning the configuration is suitable for different head sizes and shapes of adolescents and adults. The electrodes are positioned in a specific configuration on the face and behind the ear at specific locations. Wearing comfort should allow for comfortable use over several hours to days. The signal quality, with impedance values ​​in the range of a few kOhms to approximately 20 kOhms, should be well-suited for EEG, EMG, ECG, and EOG measurements. The grid configuration should include more than three electrode positions. Fig. 4aFor example, 8 (plus reference REF and ground GRD for differential measurement of potential differences) are displayed, but more are possible at the positions of the arm configurations or smaller side arms. The grid is available in variants, for example, in similar shapes but made of different materials or with different electrode designs.

[0108] A first variant of the device 100, as used, for example, in Fig. 7As shown, a fixed gel grid with fixed gel electrodes is present. For example, commercially available ECG electrodes 110 1 to 110 9 for neonatal use can be inserted into a carrier structure. Dry electrodes can also be used as an alternative to fixed gel electrodes. A carrier structure 120, which, for example, has polyurethane foam as its carrier material, forms a fixed gel grid with the fixed gel electrodes. The carrier structure has, for example, a stretchable carrier material such as polyurethane foam. The electrodes of the multiple electrodes are, for example, connected to cables, and the cable routing runs on the top surface of the patch. In other words, the cables are guided along a surface of the carrier structure 120 facing away from the electrode arrangement 110 with a clearance 140. The clearance 140 in the cable routing limits the force transmission of a stretching of the carrier structure 120 to the cables. The clearance corresponds, for example, to a length allowance in the cable length.in the form of a curved cable path. The support structure is designed, for example, to increase the distance between two electrodes of the electrode arrangement by a maximum of 20%. The in . Fig. 7 The illustrated embodiment has a support structure 120 and an electrode arrangement 110, as also found in Fig. 4b The notches at certain electrode positions serve to improve adhesion, but they could also be removed. Alternatively, the [unclear text] can also be used. Fig. 4aThe illustrated embodiment is configured as a fixed gel grid (support structure with commercially available fixed gel electrodes connected by cables). Optionally, the device 100 has a signal output 160 configured to provide an output signal based on the electrical signals measured by the plurality of electrodes 1101 to 1109. The signal output 160 is connected to the electrodes of the electrode arrangement via cables. The cables extend, for example, beyond the support structure 120 and terminate in a connector that functions as the signal output 160.

[0109] A second variant of the device 100 features a conductive track grid. In this version, conductive tracks, for example, made of a metallic material (e.g., silver or Ag / AgCl) or a graphene material, are applied to a substrate of the support structure 120, for example, via an etching process, a laser process, or a printing process. It is also possible to use a metal combination, first creating the conductive tracks using a copper etching process and subsequently silver-plating the electrode surfaces via chemical bonds. Printed (or etched) electrode systems on foil substrates are advantageous because they can be easily adhered to the skin. Furthermore, adhesive solutions, i.e., printed conductive tracks on a substrate that can be adhered to the skin, are more robust against artifacts caused by movement of the electrodes on the skin. The substrate material is, for example, a semi-flexible, i.e., stretchable or elastic, thin, foil-like material (e.g.,a polymer material, such as polyester or polyamide, or a polyurethane or silicone material). Polyurethane is preferred because, in addition to being skin-friendly as a biocompatible material, it allows for stretchability and elasticity, and flexibility in more than one dimension. This allows the grid, i.e., the support structure 120, to conform to facial and head contours. For insulation, the conductive tracks are covered, for example, as a sandwich construction with a second layer of the support material of the support structure 120, whereby the electrode surfaces (in the . Figures 4a and 4b(represented as circles) remain isolated. The conductor tracks have, for example, a looped course on or within the support structure 120 (e.g., wavy, meandering, or jagged) in order to lengthen correspondingly when the support structure 120 is stretched. The support structure is thus designed to increase the distance between two adjacent electrodes of the electrode arrangement by a maximum of 10%.

[0110] A schematic diagram of the structure is in Fig. 8aThe diagram shows that A is polyurethane, C is copper, and B is silver plating. The support structure 120 of the device 100 thus comprises, for example, a first layer of support material, a second layer of support material, and an intermediate layer comprising a conductive material, such as copper. At the positions on the support structure 120 where the electrodes of the electrode assembly are located, the second layer of support material has a gap. At these locations, the conductive material of the intermediate layer is, for example, silver-plated or covered with graphene. Subsequently, a gel, such as an adhesive electrolyte gel or a solid gel, is applied or pre-applied to the silver-plated area on the support structure 120. Fig. 8bFigure 1 shows the setup after pre-application of the gel (D), but without a cover from an optional protective film. It is important that the gel does not come into contact with the copper conductor track, as this would cause chemical reactions. The gel material, which is arranged on the silver-plated electrode surface, can be described, for example, as a gel lens. The free electrode surfaces (in the Figures 4a and 4bThe electrodes (represented as circles) are coated with an electrolyte gel lens. This is exposed by the user, for example, by peeling back a protective film immediately before applying the grid. The protective film areas are, for example, subdivided, so that the arms of the grid can be applied one after the other. Optionally, the application of the gel to the electrode site can be omitted (the multiple electrodes thus feature, for example, dry electrodes) if a skin-compatible material such as graphene is used to cover the conductive material located between the two layers of carrier material.

[0111] In this second variant, and optionally also in the first variant, a stiffening element 122, which may contain, for example, polyurethane foam, can be attached for additional stabilization. Alternatively, a sub-millimeter thick adhesive surface may also be sufficient. To further stabilize the grid during application, a paper or film material can be attached to the upper (non-skin) side, i.e., the side of the support structure 120 facing away from the electrode arrangement 110, to increase rigidity. This material is removed after the grid is placed, similar to a shower plaster, resulting in greater overall wearing comfort.

[0112] According to one embodiment, the carrier structure 120 has transparent carrier materials, i.e., transparent and / or colorless carrier materials, or differently colored carrier materials, in order to achieve low (or, if necessary, particularly high) visibility of the carrier structure 120 on various skin types. The narrow grid design is suitable for everyday wear, possibly with an aesthetically pleasing print, or for remaining inconspicuous due to its transparent design. The device can thus be discreet and offer comfortable wear, making it suitable for everyday use. This facilitates long-term imaging, as it increases acceptance of the device's use in daily life. Transparent carrier materials are particularly advantageous because they allow for the rapid detection of skin irritations, such as reactions to an adhesive used to attach the carrier structure to the skin.Furthermore, transparent carrier materials facilitate self-application of the support structure, as key features are not obscured, allowing the user to efficiently and correctly position the electrodes of the electrode array. Additionally, once the electrode array is in place, it can be easily verified whether the electrodes are positioned correctly on the user.

[0113] According to one embodiment, the electrode arrangements 110 of the device 100 described herein can be configured with passive or active electrodes. Passive electrodes conduct the electrical activity via a metal surface; in the example of the "fixed gel grid variant," for instance, via a silver metal plate with a silver chloride coating (Ag / AgCl electrodes), and in the example of the "conductor track grid variant," it is a silver surface that is chemically deposited onto a copper conductor track. Another type of electrode is active electrodes, which, via specific circuits, improve the signal quality even before it enters the differential amplifier. This additional circuit can perform various functions. One possibility is impedance conversion. Similar to, for example, a microphone cable, this can, for instance, make the signal less susceptible to interference caused by cable movement.This additional circuit also allows for the integration of small amplifiers directly at the electrode. This improves the signal-to-noise ratio (SNR) at the electrode itself, resulting in better signal quality. Furthermore, the optional signal amplifier can be positioned further away from the body, as the improved signal-to-noise ratio makes cable movements less critical to signal quality.

[0114] For very large or very small head shapes (primary school children, teenagers, young adults), the configuration can be scaled, for example, to 70% of the normal size for primary school children. Based on international hat sizes regarding head circumference, sizes S, M, and L can be covered by the proposed support structure, i.e., S covers head circumferences of 55-56 cm, M 57-58 cm, and L 59-60 cm. The support structure is adapted to different head circumferences thanks to the elastic support material, with a maximum difference of 5 cm between the different head circumferences. Furthermore, the configuration should be increased by a factor of 1.1 or 1.2 so that head sizes XL (61-62 cm) can also be covered. Further corresponding increases beyond this are conceivable. Similarly, the configuration can be adjusted by a scaling factor of 0.9 or 0.8 for sizes XS (53-54 cm).Due to the softness of the carrier material of the support structure 120, it is not a problem if the support structure 120 exhibits a slight wave between the electrode positions on a somewhat smaller head. Similarly, intermediate sections can also be stretched slightly to ensure good access to the positions on the forehead and behind the ear. Adaptation to different head shapes is possible, for example, by slightly twisting / tilting the arm behind the ear. The flexible material makes this possible. Preferably, the conductive traces in areas that are twisted or stretched are printed in a looped form, e.g., in a meandering shape, so that the conductive traces can absorb the stretching or tension.The support structure is adapted by the elastic support material for positioning at least part of the electrode arrangement on the facial surface of the user's head with a head circumference in a range of 50 cm to 55 cm or 55 cm to 60 cm or 60 cm to 65 cm.

[0115] According to one embodiment, the device 100 has a signal amplifier 150 which is configured to receive a signal from a signal output (e.g. 160 in Fig. 7 or Fig. 15 ) to obtain the measured electrical signals from the device 100. The signal output 160 can optionally be arranged on the support structure 120, see e.g. Fig. 15. Fig. 15The device 100 represents, for example, a conductor grid in which the electrodes 110 1 to 110 10 are connected to the signal output 160 via conductors. The conductors are, for example, integrated into the support structure 120. The device 100 also includes, for example, a fastening means that defines the position of the signal amplifier 150 on the back of the head, an arm, a shoulder, a chest, or a neck of the user. For signal acquisition, the device 100 includes, for example, an EEG differential amplifier. To avoid cable artifacts, the amplifier should be placed near the electrodes. It is also possible to first connect to an adapter and then run a bundled, shielded cable to the amplifier. The amplifier can then also be worn, for example, with a chest strap or an armband.For mobile EEG applications, it is often worn on the back of the head using a headband in research settings; this solution is also fundamentally feasible here. The EEG amplifier either records the signals locally or transmits them to a receiving station via cable or wirelessly, e.g., via a Bluetooth connection.

[0116] For connecting the device 100 from Fig. 15 Connecting to an adapter or directly to the signal amplifier 150 generally requires a dimensionally stable / rigid reinforcement, as otherwise the connection cannot be made by simply inserting the component. For this purpose, a rigid material can be glued as a support onto the insertion piece 162 of the support structure 120. The support structure 120 has, for example, a support structure that is located at position 162 of the signal output 160 on the support structure 120. The support structure may be made of, for example, polyimide, polyester, polyethylene, and / or FR4 material.

[0117] The Signal Amplifier 150 could be worn on the shoulder or at chest level by attaching it to clothing or a carrying strap. Figures 9a to 9e They show different ways in which the amplifier can be worn advantageously on the user's body. Fig. 9a This shows one possible positioning of the connection to the amplifier or adapter at the back of the user's head using a headband. Another option is placement at the user's neck. The adapter or the amplifier itself could, for example, be attached directly to the skin using a skin-friendly adhesive patch. Alternatively, a scarf or loop worn around the neck, as shown in the diagram, could be used. Fig. 9bThe adapter or amplifier can be attached to the scarf or loop in a pocket. The scarf or loop can also serve as padding. As an alternative to the scarf, a support element can be placed around the base of the neck on the upper body. Fig. 9c Two alternatives are shown: the signal amplifier 150 can be positioned or attached directly behind the ear or, alternatively, below the ear. According to Fig. 9d The Signal Amplifier 150 can be placed on the user's shoulder, attached to clothing or a strap, or, for example, fastened to the user's chest, clothing, or a strap. However, especially for use during sleep, the following is recommended: Fig. 9eThe position shown is preferred for the amplifier or adapter. The fastening device is, for example, a collar or scarf designed to attach the signal amplifier 150 to the user's neck below the bony prominence mastoid process 280 and between the two muscles sternocleidomastoid 282 and trapezius 284.

[0118] The following section will discuss the use of the device 100 according to the invention in more detail, in particular how the user can put on the device 100 himself. The device 100 corresponds, for example, to one of the previously described embodiments.

[0119] As in Fig. 10As shown, the method 400 for using the device according to the invention comprises at least the steps of applying 410 the device 100 to a facial surface 220 of a head 200 of a user 210 and behind an ear 230 of the user by the user 210 himself or another person, and monitoring 420 the user 210 by means of the electrical signals measured by the plurality of electrodes. For the application 410, self-application 410 by the user 210 is preferred.

[0120] Optionally, the procedure 400 may include further steps described below: The procedure may include cleaning the head surface, i.e., the skin, with the cleaning optionally being limited to the areas where the device 410 is applied. Cleaning the skin with an alcohol solution to remove dirt, grease, and sebum is advantageous for better signal quality. Alternatively or additionally, the cleaning, e.g., the pretreatment of the head surface, may be performed with an abrasive gel, as is often the case with ring electrodes. A technical problem is the low signal strength of the potential difference in the range of 0.1 to 100 microvolts. For this reason, the contact between the electrode and the skin must be established with the best possible conductivity. The impedance value of the skin is in the range of a few kOhms to MOhms. To keep this value low, the areas where the electrodes are positioned are, e.g.,It is degreased with alcohol and, if necessary, treated with a peeling-like gel to remove grease, sebum or dead skin cells.

[0121] In one embodiment of the device 100, the support structure 120 has an adhesive material that is, for example, covered by a protective film. The underside of the support structure, i.e., the side of the support structure on which the electrode arrangement is located, is, for example, covered with the protective film. Beneath this is an adhesive surface made of the adhesive material on the grid arms, i.e., on the connecting webs of the support structure. At the electrode positions, a gel lens is, for example, arranged to provide a signal-technically advantageous connection between the skin and the electrode. Before the protective film is removed to attach the device to the skin, a pre-positioning procedure is performed, for example. The application 410 of the device can thus, for example, involve the following steps: Pre-positioning the device on the head surface, i.e. on the face surface 220 and behind the ear 230, peeling off the protective film from the device, and sticking the device to the head surface.

[0122] The peeling and sticking process can be repeated several times, for example, if the device has multiple protective film sections. The sequence in which each protective film section is peeled off can be determined, for example, as already described above in connection with the device.

[0123] Via the two electrodes A and B (designations from Figure 5a and Figure 5bFor example, pre-positioning is achieved by palpating the upper cheekbone, pre-positioning electrode B there, and pre-positioning electrode A on an approximately horizontal line. Then, it can be checked whether the upper grid arm can be positioned above the eye, approximately towards the center of the forehead (C). Similarly, it can be checked whether the left arm of the grid (D) fits well behind the ear. For ease of handling, the design therefore chose to run the arm above the ear, as this allows for natural support on the upper base of the ear during placement. By slightly rotating the device around point F, the positions of the left and upper arms (i.e., the positions of the two parts 124 1 and 124 2 into which the second connecting bridge 124 divides) can be optimized.Using a free hand and a skin-friendly pen, the positions of (A) and (B) on the face can also be visibly marked, so that if the hand slips, it can be easily corrected.

[0124] After pre-positioning, the protective films can be removed, starting with the arm containing electrodes A and B. Then, the arms of the grid, i.e., the connecting struts of the support structure, can be attached in the sequence specified during pre-positioning (C, D). The protective film is divided into corresponding sections, allowing the arms of the grid to be attached individually, one after the other.

[0125] The application 410 of the device 100 to the facial surface 220 of the head 200 of the user 210 can thus include, for example, the steps of palpating an upper cheekbone and attaching a first electrode to the upper cheekbone; attaching a second electrode in front of the tragus of one of the user's ears; attaching a third electrode to a forehead vertically above a nasion in an area of ​​1-3 cm above an eyebrow line; and attaching a fourth electrode behind the ear.

[0126] To describe the placement: 1. Locate the cheekbone and the hairless area (important for use with beards) in front of the ear (approximately 1 cm in front of the tragus, the "cartilaginous bump"). Place the two short arms of the grid on these points, roughly horizontally. 2. Roughly align the grid on the forehead and behind the ear, rotating it via point F if necessary. 3. Apply the grid in sections, starting at the cheekbone and in front of the tragus. 4. On the forehead, align the point vertically upwards from the nasion towards the forehead, approximately 1-2 cm above the eyebrow line. A horizontal deviation of 1-2 cm is acceptable. 5. Behind the ear, the last electrode typically reaches the mastoid process, a palpable bony protrusion. This electrode is typically chosen as the reference for measuring potential differences.

[0127] An optional version of the grid includes a third arm (E) that is attached along the chin to record electromyography (EMG) via electrodes in the chin area. Such recording is advantageous for assessing sleep stages, particularly for differentiating the Rapid Eye Movement (REM) phase from others, especially wakefulness. The complete grid design with the electrodes on the chin for EMG recording is intended for use in home sleep monitoring.

[0128] The grid's ease of handling and the described application method ensure reliable placement on the first attempt. Repositioning it would result in a loss of adhesive strength, increasing the risk of signal stability not being maintained over extended periods.

[0129] The area above the ear, for example, is designed to be used as an adhesive surface, preventing the grid from sticking to the hair. Besides aiding grid placement, this arm also serves as a connection between the face and the arm behind the ear. An alternative design below the ear is possible; this runs over the jawbone, which can compromise electrode placement stability with increased jaw activity and is also somewhat less comfortable to wear.

[0130] For the acquisition of electrophysiological signals, particularly electroencephalograms (EEG), electrooculograms (EOG), electrocardiograms (ECG), and electromyograms (EMG), electrodes are brought into contact with the skin via a gel (wet electrodes) to measure electrical activity generated by brain and muscle cells. Potential fluctuations of an electrode are measured in relation to a reference electrode; signal amplification is achieved, for example, using a differential amplifier. When using wet electrodes, an electrolyte gel is applied to reduce the contact impedance between the skin and the electrode.

[0131] Using step 420, the user's sleep behavior or cognitive behavior can be monitored based on the measured electrical signals.

[0132] Possible technical applications include those described below: Home or outpatient sleep monitoring; home or outpatient monitoring of patients with epilepsy or suspected epilepsy (not covered by the claimed procedures); home or outpatient monitoring of patients with other neurological diseases or suspected neurological diseases (e.g., depression, Alzheimer's disease), among other things, for deriving early indicators (not covered by the claimed procedures); use in cognitive-psychological test series, for example, for attention, vigilance, listening effort, cognitive load, determination of sensory functionality, and cognitive processing ability of the patient at home, in nursing homes, but also in private practices or clinics, since the simple installation of the electrodes saves time here as well; use for recording the aforementioned cognitive states in work situations, especially for safety-critical applications (e.g.,Train drivers, pilots, air traffic controllers, truck drivers, mining vehicles) in neuropsychological research and related research areas on cognitive states, but also on neurological disease symptoms in the waking state, but also in the sleeping state (not falling under the claimed methods); recording of acoustic attention for subsequent analyses or for controlling a hearing aid, for example to improve the speech signal of an attended speaker; recording of listening effort for subsequent analysis or also for controlling the settings of a hearing aid; monitoring of the effectiveness of positive air pressure systems for the treatment of apnea, whereby such methods do not fall under the claimed methods.

[0133] Positive air pressure (PAP) systems are one of the therapies for sleep apnea. Typically, sleep apnea is first diagnosed in a sleep lab, followed by the initial setup of the PAP device, also in a sleep lab. However, in many cases, this setup is not sufficiently effective in practice, and sleep is usually monitored at intervals using polygraphy (without EEG). The solution proposed here could offer an improvement, as data collection remains possible at home, but provides higher-quality information about sleep architecture via EEG.

[0134] Fig. 11Figure 1 shows a block diagram for the setup of the data acquisition system with the device 100. Individuals can take a data acquisition system 500 home and use it themselves. The system includes, for example, an EEG amplifier 150, a recording unit 410, and optionally further sensors 420, as well as the device 100 according to the invention described herein.

[0135] Fig. 12 This also relates to an embodiment of a system 500 that includes the device 100 according to the invention. Additionally, the system 500 has an evaluation arrangement 510 configured to evaluate the electrical signals measured by the plurality of electrodes. Optionally, the system 500 can include features and functionalities such as those associated with Fig. 11 have been described, exhibit.

[0136] The evaluation arrangement 510 is designed, for example, to receive the electrical signals measured by the multitude of electrodes from a signal output 160, e.g., via a signal amplifier 150. This can be done, for example, wirelessly via WLAN or Bluetooth, or via a wired connection.

[0137] The evaluation arrangement 510 is, for example, designed to provide information 520 about the user's sleep architecture based on electrical signals; or to provide information 520 about the user's epileptic behavior; or to indicate a user's neurological disorder 520; or to provide cognitive-psychological information 520.

[0138] According to an alternative embodiment, the system 500 further comprises a hearing aid 530. In this case, the evaluation arrangement is designed, for example, to control the hearing aid 530 based on the electrical signals.

[0139] The evaluation arrangement 510 can be configured, for example, to: to record acoustic attention for subsequent analysis and / or to control the hearing aid 530, for example to improve the speech signal of an attended speaker; and / or to record listening effort for subsequent analysis and / or also to control the settings of the hearing aid 530.

[0140] The added value of the solution proposed here is that, based on the self-applying device 100 in a predefined configuration of electrodes 110 1 to 110 5 (The configuration of the electrodes can be in accordance with an embodiment described herein, see e.g. the Figure 1a , 4a , 4b and 6a / bIn addition to ECG and EMG, EEG and EOG information can be advantageously recorded in everyday life for the proposed application and thus connected to the 530 hearing aid and, optionally, to an EEG / EOG signal amplifier. Device 100 in the 500 system is particularly advantageous when the electrode arrangement uses wet electrodes. Solutions with dry electrodes in the ear canal or auricle exist, but these can create uncomfortable pressure or offer inferior signal quality. The solution proposed here combines wearing comfort with good signal quality. If EEG can be recorded in everyday life in this way, the applications mentioned are conceivable in conjunction with a hearing aid. The detection of acoustic attention to a specific speaker in a multi-speaker situation (or to a sound in a noisy environment) is based on EEG and correlates the EEG with the envelope of the target audio signal (scientific papers on this topic have been published for several years). Once the target signal has been detected in this way, the beamformer of the hearing aid can be adjusted to emphasize this target signal and make it more audible to the listener. In the aforementioned application, a particular challenge is allowing the listener to "come out" of the supported situation, that is, enabling them to refocus on other speech sources, even though these are now more in the background.One solution based on the proposed electrode grid is to obtain information about eye movement (direction), blinking, and eye closure via the EOG and use this information as a kind of remote control. This allows the listener to control, in a much more robust yet simple and intuitive way, which signal should be emphasized (for example, looking in the direction, blinking twice to confirm). The evaluation arrangement 510 can thus be configured to analyze the signals measured by the device 100 for predetermined signal characteristics in order to control the hearing aid 530 in response to user signals. By recording listening effort based on EEG data, the hearing aid algorithms can be automatically adjusted as listening effort increases, for example, to a different pre-programmed profile of the hearing support algorithms.However, analyzing the audio context can also provide an additional source of information for selecting the hearing assistance algorithm.

[0141] Another embodiment relates to a method 600 for manufacturing the device 100 according to the invention, see Fig. 13 Method 600 includes, among other things, the steps of providing 610 a support structure 120 and attaching 620 an electrode arrangement 110 to the support structure 120, and optionally applying 630 electrolyte gel or gel lenses to electrodes of the electrode arrangement. The electrode arrangement has, for example, a plurality of electrodes. During the application 630, for example, a gel lens or electrolyte gel can be applied 630 to only a portion of the plurality of electrodes, or a gel lens or electrolyte gel can be applied 630 to each electrode of the plurality of electrodes.

[0142] The electrode arrangement includes a multitude of electrodes for measuring electrical signals on the facial surface of a head and behind an ear of a user of the device.

[0143] The support structure is adapted to the facial surface of the user's head. Without external force from the user, the support structure is dimensionally stable within a tolerance range, and under external force from the user, it is deformable to change the distance between two adjacent electrodes and / or to adapt to facial and head structures across their entire surface. Furthermore, the support structure defines at least a partial relative position of the electrodes within the multiple electrodes. The support structure is designed to position at least part of the electrode arrangement on the facial surface and behind the ear. The multiple electrodes of the electrode arrangement can, for example, be divided into a first subset of electrodes and a disjoint second subset of electrodes, with the support structure, for example,is trained to position the first subset of electrodes on the surface of the face and to position the second subset of electrodes behind the ear.

[0144] The electrode arrangement 620 can be attached, for example, as already described in connection with the device 100. In particular, reference should be made to the exemplary embodiments in the Figure 7 , 8a and 8b referred to. For example, as in Fig. 7 As shown, pre-fabricated wet electrodes are glued onto the support structure or, as in the Figures 8a and 8b As shown, the electrode arrangement is integrated into the support structure. Integrating the electrodes into the support structure is particularly advantageous when they are connected to conductor tracks. A sandwich structure, as shown in the Figures 8a and 8b As shown, it protects the user of the device, since the conductor tracks are not skin-friendly and is necessary for the electrical insulation of the conductor tracks.

[0145] Fig. 16 Figure 1 shows a support structure 120 designed to position the plurality of electrodes 1101 to 1104 of the electrode arrangement 110 only behind the ear 230. For this purpose, the support structure 120 has, for example, a part 800, such as a bracket, designed to rest on the user's ear when positioning and / or attaching the device 100 behind the ear. This enables the user to independently attach the device 100 behind the ear.

[0146] Electrodes 110 1 to 110 4 may, for example, have the same characteristics, positions and / or functionalities as electrodes 110 4 to 110 7 in Fig. 4a Optionally, an extension 130, such as that shown in connection with electrodes 110 4 and / or 110 5 in [reference], can be provided on electrode 110 1 and / or electrode 110 2. Fig. 4bThe electrodes 110 1 to 110 4 can be connected, for example, by conductor tracks or cables.

[0147] The multiple electrodes 1101 to 1104 of the electrode arrangement 110 are designed for measuring electrical signals behind the user's ear. Preferably, the electrode arrangement comprises multiple wet electrodes. The electrode arrangement 110 is, for example, arranged on or integrated into the support structure 120.

[0148] The shape of the carrier structure 120 follows, for example, the shape of the user's ear. The carrier structure 120 defines, at least partially, a relative position of the multiple electrodes to one another. The shape and length of the carrier structure are designed, for example, to extend from the upper part of the ear along the ear to the mastoid process. This is particularly advantageous for self-application of the device 100, as the user can very precisely locate either the upper part of the ear or the mastoid process and thus position and attach the device or the carrier structure 120 behind the ear.

[0149] The support structure 120 is dimensionally stable within a tolerance range without external force from a user and deformable under external force from the user in order to change a distance between two adjacently arranged electrodes and / or to adapt to facial and head structures across the entire surface.

[0150] Furthermore, it should be noted that the device 100 may have features and functionalities as described herein in connection with other embodiments of the device 100 according to the invention, see e.g. Figs. 1a to 9e In particular, the support structure 120 can, for example, have extensions 130 on the electrodes of the plurality of electrodes. Furthermore, the support structure 120 can have features such as adhesive material, protective films and stiffening elements.

[0151] Although some aspects have been described in connection with a device, it is understood that these aspects also constitute a description of the corresponding process, such that a block or component of a device can also be understood as a corresponding process step or as a feature of a process step. Similarly, aspects described in connection with or as a process step also constitute a description of a corresponding block, detail, or feature of a corresponding device. Some or all of the process steps can be performed by (or using) a hardware apparatus, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, some or more of the key process steps can be performed by such an apparatus.

[0152] Depending on specific implementation requirements, embodiments of the invention can be implemented in hardware or in software. The implementation can be carried out using a digital storage medium, for example, a floppy disk, DVD, Blu-ray disc, CD, ROM, PROM, EPROM, EEPROM, FLASH memory, hard disk, or other magnetic or optical storage medium, on which electronically readable control signals are stored. These control signals can interact with, or interact with, a programmable computer system in such a way as to execute the respective method. Therefore, the digital storage medium can be computer-readable.Some embodiments according to the invention therefore include a data carrier which has electronically readable control signals which are able to interact with a programmable computer system in such a way that one of the methods described herein is carried out.

[0153] In general, embodiments can be implemented as a computer program product with a program code, wherein the program code is effective in carrying out one of the methods when the computer program product runs on a computer.

[0154] The program code can also be stored on a machine-readable medium, for example.

[0155] Other unclaimed embodiments include the computer program for carrying out one of the methods described herein, wherein the computer program is stored on a machine-readable medium.

[0156] In other words, an unclaimed embodiment of a method is a computer program that includes program code for performing one of the methods described herein when the computer program is run on a computer.

[0157] Another unclaimed embodiment of the methods is therefore a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for carrying out one of the methods described herein is recorded. The data carrier, the digital storage medium, or the computer-readable medium is typically tangible and / or non-perishable or non-temporary.

[0158] Another unclaimed embodiment of the method is thus a data stream or a sequence of signals that represents the computer program for carrying out one of the methods described herein. The data stream or sequence of signals can be configured, for example, to be transferred via a data communication connection, such as the Internet.

[0159] Another unclaimed embodiment comprises a processing device, for example a computer or a programmable logic device, configured or adapted to perform one of the methods described herein.

[0160] Another unclaimed embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

[0161] Another unclaimed embodiment comprises a device or system designed to transmit a computer program for carrying out at least one of the methods described herein to a receiver. The transmission can be, for example, electronic or optical. The receiver can be, for example, a computer, a mobile device, a storage device, or a similar device. The device or system can, for example, include a file server for transmitting the computer program to the receiver.

[0162] In some embodiments, a programmable logic device (for example, a field-programmable gate array, an FPGA) can be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field-programmable gate array can interact with a microprocessor to perform one of the methods described herein. Generally, in some embodiments, the methods are performed by any hardware device. This can be general-purpose hardware such as a computer processor (CPU) or method-specific hardware such as an ASIC.

[0163] The devices described herein can be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0164] The devices described herein, or any components of the devices described herein, may be implemented at least partially in hardware and / or in software (computer program).

[0165] The methods described herein can be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0166] The methods described herein, or any components thereof, may be executed at least partially by hardware and / or by software.

[0167] The embodiments described above merely illustrate the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be obvious to other people skilled in the art. Therefore, it is intended that the invention be limited only by the scope of protection set forth in the following claims and not by the specific details presented herein by way of description and explanation of the embodiments.

Claims

1. Device (100) comprising: an electrode arrangement (110) with a plurality of electrodes for measuring electric signals on a face surface (220) of a head (200) of a user (210) and behind an ear (230) of the user (210), wherein the electrodes of the plurality of electrodes are wet electrodes and / or dry electrodes ; a carrier structure (120); wherein the carrier structure (120) at least partially defines a relative position of the electrodes to one another; and wherein the carrier structure (120) is shape-stable within a tolerance range without external force exerted by a user (210) and deformable under external force exerted by the user (210), in order to change a distance between two adjacently arranged electrodes and to area-comprehensively adapt to face and head structures, wherein the carrier structure (120) is configured to position at least a part of the electrode arrangement (110) on the face surface (220) and behind the ear (230); wherein the carrier structure (120) is configured in the shape of a net structure with branching connecting ribs that follow a course of the face surface (220); and wherein the branching connecting ribs comprise a rib width corresponding to, at most, three times the electrode diameter of an electrode of the plurality of the electrodes.

2. Device (100) according to claim 1, wherein the carrier structure (120) follows the face surface (220) as a human face shape, and the plurality of electrodes are arranged on the carrier structure (120); wherein a first electrode position that is assigned to a first electrode (1101) of the plurality of electrodes corresponds to a position of a first distinctive point (B) of the face surface (220); and a second electrode position that is assigned to a second electrode (1102) of the plurality of electrodes corresponds to a position of a second distinctive point (A) of the face surface (220); and a third electrode position that is assigned to a third electrode (1103) of the plurality of electrodes results starting from the first electrode position and the second electrode position on the face surface (220) within a tolerance range determined by the carrier structure (120).

3. Device (100) according to claim 2, wherein the first distinctive point (B) of the face surface (220) corresponds to an upper cheekbone, and the second distinctive point (A) corresponds to a position in front of the tragus of an ear (230) of the user (210); and wherein the carrier structure (120) includes a connecting rib (123, 1241) that at least partially connects the first electrode position and / or the second electrode position, on one side, to the third electrode position, on the other side, and wherein the third electrode position corresponds, within a tolerance range of 1 to 2 cm determined by the carrier structure (120), to a position (C) on a forehead of the face surface (220) in an area of 1 cm to 3 cm above the eyebrow line, vertically above a nasion of the user (210); and / or wherein the carrier structure (120) includes a connecting rib (123, 1241) that at least partially connects the first electrode position and / or the second electrode position, on one side, to a fourth electrode position that is assigned to a fourth electrode (1104) of the plurality of electrodes, on the other side, and wherein the fourth electrode position corresponds, within a tolerance range determined by the carrier structure (120), to a position (D) behind the ear (230) of the user (210); and or wherein the carrier structure (120) includes a connecting rib (126) that at least partially connects the first electrode position and / or the second electrode position, on one side, to a fifth electrode position that is assigned to a fifth electrode (1109; 1108) of the plurality of electrodes, on the other side, and wherein the fifth electrode position corresponds, within a tolerance range determined by the carrier structure (120), to a position (E) on the chin of the face surface (220) of the user (210).

4. Device (100) according to one of the preceding claims, wherein the carrier structure (210) comprises an adhesive material for affixing the plurality of electrodes and the carrier structure (120) on the face surface (220), wherein the electrodes further comprise an adhesive electrolyte gel for lowering the impedance and for affixing the plurality of electrodes and the carrier structure (120) on the face surface (220); wherein the adhesive electrolyte gel is covered, at least in some sections, by a removable protective film, and wherein the adhesive material is covered by a removable protective film, wherein the protective film comprises a plurality of protective film portions that are independently removable from the carrier structure (120) and the plurality of electrodes.

5. Device (100) according to any one of claims 1 to 4, wherein a connecting rib (1242) of the branching connecting rib is curved at one end so that the carrier structure (120) comprises a curved end piece that is configured to be affixed behind an ear (230) of the user (210), and wherein the connecting rib is configured to run from the face of the user (210) above the ear (230) to the curved end piece, and wherein at least one electrode of the plurality of electrodes is arranged at the curved end piece.

6. Device (100) according to any one of claims 1 to 5, wherein a shape of the carrier structure (120) is configured to position the plurality of electrodes at a corresponding plurality of positions on the face surface (220); wherein the plurality of positions is configured for a detection of the electric signals on the face surface (220) for at least one linear combination of the electric signals for mapping signals from a predetermined head region of the user (210).

7. Device (100) according to one of the preceding claims, wherein the carrier structure (120) comprises polyurethane material, polymer material, and / or silicone material as a carrier material, wherein the carrier material is elastic or stretchable; wherein the electrodes are connected to conductive traces, and wherein the conductive traces have a slung course on or in the carrier structure (120) in order to correspondingly extend upon stretching of the carrier structure (120), and wherein the carrier structure (120) is configured to extend a distance between two electrodes of the electrode arrangement (110) by a maximum of 10 %.

8. Device (100) according to one of the preceding claims, wherein on a side facing away from the electrode arrangement (110), the carrier structure (120) comprises a removable stiffening element (122) that is configured to at least locally stiffen the carrier structure (120).

9. Device (100) according to one of the preceding claims, wherein the carrier structure (120) comprises at least one extension (130) having an adhesive material at a position at which an electrode of the electrode arrangement (110) is arranged.

10. Device (100) according to one of the preceding claims, wherein the plurality of electrodes comprises active electrodes comprising a circuit that is configured to perform an impedance conversion of the measured electric signal, and / or amplify the measured electric signal.

11. System (500) comprising: a device (100) according to any one of claims 1 to 10; and an evaluation arrangement (510) that is configured to evaluate the electric signals measured by the plurality of electrodes.

12. System (500) according to claim 11, wherein the evaluation arrangement (510) is configured to, based on the electric signals provide an information (520) on a sleep architecture of the user (210); or provide an information (520) on an epileptic behavior of the user (210); or indicate (520) a neurological disorder of the user (210); or provide a cognitive psychological information (520).

13. System (500) according to claim 11, comprising a hearing aid (530); wherein the evaluation arrangement (510) is configured to control the hearing aid (530) based on the electric signals, wherein the evaluation arrangement (510) is configured to correlate the signals measured by the device (100) with an envelope of an audio signal recorded by the hearing aid (530) in order to control a beam former of the hearing aid (530).

14. Method (400) for using the device (100) according to any one of claims 1 to 10, comprising the steps of: applying (410) the device (100) on a face surface (220) of a head (200) of a user (210) by the user themselves or by another person; monitoring (420) the user (210) by means of the electric signals measured by the plurality of electrodes.

15. Method (400) according to claim 14, wherein the application of the device (100) on the face surface (220) of the head (200) of the user (210) comprises the following steps: feeling an upper cheekbone and affixing a first electrode on the upper cheekbone; affixing a second electrode in front of the tragus of an ear (230) of the user (210); affixing a third electrode on a forehead, vertically above a nasion, in an area of 1-3 cm above an eyebrow line; affixing a fourth electrode behind the ear (230).