WO2010081470A1

WO2010081470A1 - Electrode system for non-invasively measuring bioelectric signals

Info

Publication number: WO2010081470A1
Application number: PCT/DE2010/000043
Authority: WO
Inventors: Gabriel Curio; Vadim Nikulin
Original assignee: Charité - Universitätsmedizin Berlin
Priority date: 2009-01-19
Filing date: 2010-01-19
Publication date: 2010-07-22
Also published as: DE102009005414A1

Abstract

The invention relates to an electrode system for non-invasively measuring bioelectric signals, in particular an EEG electrode system, comprising at least one electric connecting line (1) and an electrode component (T), which is designed as a measuring and holding element and which is coupled to the electric connecting line (1).

Description

Electrode arrangement for non-invasive measurement of bioelectric signals

The invention relates to an electrode arrangement for the non-invasive measurement of bioelectric signals, in particular EEG electrode arrangement (EEG - Elektroenzephalogra- fie).

Background of the invention

Such electrode arrangements allow the measurement of bioelectric signals to living beings. In the form of an EEG electrode, they are used to measure brain waves. They are known in various embodiments.

First, it is known to arrange EEG electrodes for carrying out a measurement of brain currents in holders, which in turn are formed on a cap or a network structure. The cap or the net structure are then turned upside down. Such caps or nets are often made of a rubbery material. The use of elastic fibers to form a network structure can also be provided. Disadvantage of this type of application of EEG electrodes is that the cap or the network structure often exerts pressure on the head of the patient, which is perceived by the wearer as unpleasant and in some cases even can obstruct the circulation in the head of the wearer , In addition, the location of the EEG electrodes in the cap or mesh structure is fixed and can not be changed.

Furthermore, EEG electrodes for non-invasive use are known, in which the electrode arrangement to be attached to the head comprises, on the one hand, an electrode component which serves to detect the measurement signals and, on the other hand, holding means which serve for fastening the electrode component to the head of the patient. Such electrode arrangements are disclosed, for example, in documents WO 01/01857 A1, US Pat. No. 6,640,122 B2 and WO 01/01856 A1. The holding means serve to attach the electrode member to the hair of the patient so as to bring the measurement serving electrode member in the vicinity of the scalp and ultimately in contact with it. This type of electrode assembly is regularly of complicated construction and therefore expensive to manufacture. The same construction principle is followed by an EEG electrode from the document US Pat. No. 4,067,321 an electrical connection line is connected to a plate-shaped electrode. To hold the electrode, an insulating plate and several legs are then formed on the insulating plate.

Cerebral current measurements are not only used in the medical environment. Rather, their collection was proposed, for example, in the work and leisure environment.

Summary of the invention

The object of the invention is to provide an improved electrode arrangement for non-invasive measurement of biolectric signals, which is easy to produce and with little effort. In addition, the comfort of wear for the patient should be improved.

This object is achieved by an electrode assembly for non-invasive measurement of biolectric signals, in particular EEG electrode assembly, according to the independent claim 1. Advantageous embodiments of the invention are the subject of dependent subclaims.

The invention encompasses the idea of an electrode arrangement for the non-invasive measurement of biolectric signals, in particular EEG electrode arrangements, comprising at least one electrical connection line and an electrode component designed as a measuring and holding element, which is coupled to the electrical connection line.

With the proposed electrode arrangement, the design principle common in the prior art, in particular for EEG electrodes, is surprising with an electrode component, which serves for detecting the measurement signals, and a holding means or component, which serves to secure the electrode component to the head of the patient overcome simple way. Rather, it is provided that the electrode component itself is designed as a measuring and holding element and thus fulfills the measuring function and is also prepared for a holding element-free attachment to the head. Usually, the attachment of the electrode component at the head then takes place with the aid of a locally applied paste, cream or emulsion. A gel can also be used. The prior art additional material and manufacturing costs for the holding means for receiving the E Lektrodenbauteils, so for example, the cap or the network structure or the holding components of individual electrodes, is saved.

With the aid of the created electrode arrangement, improved miniaturization in connection with electrode arrangements for non-invasive measurement of bioelectric signals, in particular EEG electrode arrangements, is furthermore achieved. This is preferably associated with a weight reduction. When used as an EEG electrode arrangement, increased spatial sampling of the EEG potential distribution on the scalp is possible due to the improved miniaturization.

The measurement signals detected by means of the electrode component are supplied to signal processing via the electrical connection line, for example signal amplification. At the distal end of the electrical connection line with respect to the electrode component, a connection means may be formed, for example in the form of a plug. In the simplest case, the connection of the electrical connection line to the further signal processing but also via a wire end of the connecting cable can be done.

The created electrode arrangement is also particularly suitable for use in connection with a so-called brain computer interface ("brain-computer interface") .In experimental investigations it was found in this context that it was possible in an online application, the To control the position of a cursor on a computer screen with an accuracy of about 78%.

In field trials it has been found that the proposed electrode arrangement shows a high positional stability at the head of a subject. Accelerations greater than 2.5 g (g = 9.8 m / s ² ) were tested. Such head movements took place with far greater acceleration than natural head movements. The electrode arrangement was stable in position.

A preferred embodiment of the invention provides that the electrode component is formed with at least one Befestigungsöffhung. With the aid of the attachment opening, the electrode component is designed according to a possible embodiment for its holding function. When attaching the electrode component to the head of the patient, the fastening opening penetrates. The locally applied cream, paste or emulsion, whereby a sufficient local fixation of the electrode member is achieved.

In an expedient embodiment of the invention it can be provided that the electrode component is formed from an electrically conductive material. In particular, a wire material may be provided. As a wire material, for example, the material Ag / AgCl, carbon fibers or other electrically conductive materials are used. In one embodiment of the invention, the wire material used for the wire electrode has an outer diameter of about 0.2mm to about 0.7mm, preferably from about 0.3mm to about 0.6mm. This supports sufficient sensitivity for signal acquisition.

An advantageous embodiment of the invention provides that the electrode component is formed with a loop-shaped electrode section. The electrode component may be formed in a configuration as a closed loop. For example, the loop-shaped electrode section is produced as a wire loop section.

Preferably, a further development of the invention provides that the loop-shaped electrode section has an outer diameter between about 1 mm and about 3 mm, preferably between about 1 mm and about 2 mm.

In an advantageous embodiment of the invention can be provided that the electrode member is formed with a hook-shaped electrode portion. An outer diameter of the hook-shaped electrode portion may be between about 1 mm and about 3 mm, preferably between about 1 mm and about 2 mm. In the design as an EEG electrode arrangement, the proposed dimensioning allows both an optimized positioning on the hairy head as well as a significantly increased spatial sampling of the potential distribution.

A development of the invention can provide that the electrical connection line is formed from a flexible wire material. The flexible wire material preferably has an external electrical insulation. The wire material is, for example, copper. Preferably, the flexible wire material is formed as einadriges material. The outer diameter of the flexible wire material is in a preferred embodiment less than about 70μm, preferably less than about 50μm. When designed as an EEG electrode arrangement, the design for wearing comfort on the one hand minimizes the weight and on the other hand an optical 'unobtrusiveness' of the measurement, since such wire material can be visually inconspicuous placed in the hair.

A preferred embodiment of the invention provides that the electrical connection line with a length of at least about 30cm. Suitably, the electrical connection line is formed in a development with a length of at most about 100cm.

In an advantageous embodiment of the invention can be provided that a total weight for the electrical connection line and the electrode component is less than about 50mg, preferably less than about 40mg and more preferably less than about 30mg.

An advantageous embodiment of the invention provides that the electrode component is formed adhesive or adhesive-free. In contrast thereto, it is known from the prior art to provide the electrode component and / or the electrical connection line with adhesive or adhesive in order to support the attachment to the head of the patient, which however often leads to adhesions with head hairs.

Preferably, a development of the invention provides that the electrical connection line is formed adhesive or adhesive-free.

An advantageous embodiment of the invention provides a disposable article execution.

Description of preferred embodiments of the invention

The invention will be explained in more detail below with reference to preferred embodiments with reference to figures of a drawing. 1 shows a schematic representation of an electrode arrangement with an electrical connecting line and an electrode component coupled thereto, FIG. 2 shows a schematic illustration of a hook-shaped electrode component, FIG. 3 shows a graph for measured EEG signals and FIG. 4 shows a graphic representation of FIG time-dependent EEG signals. 1 shows a schematic representation of an electrode arrangement which, in the exemplary embodiment shown, is designed as an EEG electrode arrangement. In the case of the EEG electrode arrangement, an electrode component 2 is coupled to an electrical connection line 1 at the end. The electrode component 2 is designed in the illustrated embodiment as an EEG wire electrode with a loop shape. In a practical realization, an Ag / AgCl wire with an outer diameter of the electrode component 2 of about 3 mm was used as the wire material. The electrical connection line 1 was made of a copper wire, which has an external electrical insulation. The length of the electrical connection line 1 was about 50cm. The outer wire diameter was about 50μm.

According to FIG. 1, a connector 3, which serves to couple the EEG electrode arrangement to a signal processor, for example a signal amplifier, is furthermore coupled to the electrical connection line 1.

In the non-invasive application of the EEG electrode arrangement, a cream, a paste, an emulsion or a gel is applied locally to the head of the patient, into which then the electrode component 2 designed as a measuring and holding element is pressed. In a further advantageous embodiment, the electrode component 2 can be provided with a gel droplet and applied to the scalp by means of an applicator. In each case, the locally applied substance then penetrates into a fastening opening 4 in the electrode component 2, whereby it is fastened. An electrically conductive contact between the electrode component 2, which fulfills the function of a measuring electrode, and the scalp of the patient is produced via the substance, so that brain waves can be detected. A similar use of the EEG electrode arrangement may be provided in animal experiments.

A similar electrode arrangement may be provided for the measurement of other bioelectrical signals, including, for example, the electromyogram, the electrocardiogram, the electrooculogram, the electrogastrogram, and the galvanic skin reaction.

2 shows a schematic representation of another electrode component 20, which is designed as a measuring and holding element with a hook-shaped form. The attachment opening 4 is only partially enclosed, preferably at least about 2/3. The hook-shaped Shape also supports the attachment function, since hairs can easily enter the mounting hole 4.

The EEG electrode arrangement described above with reference to FIG. 1 as an embodiment was used to measure brain waves. The measurement results are shown in FIGS. 3 and 4.

Fig. 3 shows a graph of measured spontaneous EEG signals with the patient's eyes closed. Curve 100 was recorded with a standard EEG electrode. For detecting the curve 200, the EEG electrode described above with reference to FIG. 1 as the preferred embodiment was used. In the range of the frequency of 10 Hz results in a pronounced maximum, the so-called alpha rhythm, which is very similar in the curves 100 and 200. The differences in the curves 100 and 200 occurring at higher frequencies are due to the not exactly exact match of the measuring positions of the electrodes.

Fig. 4 shows a graph for measured evoked EEG signals. High frequency oscillations are shown triggered by stimulation of the right median nerve. The brain current response of less than about 15 oV was recorded for about 30 ms. Curve 300 shows the measurement using a standard EEG electrode. For detecting the curve 400, the EEG electrode mentioned above with reference to FIG. 1 was again used as the exemplary embodiment. This results in a nearly identical signal noise behavior. Time zero refers to the moment of stimulation.

The features of the invention disclosed in the above description, the claims and the drawings may be of importance both individually and in any combination for the realization of the invention in its various embodiments.

Claims

claims

1. An electrode arrangement for the non-invasive measurement of biolectric signals, in particular EEG electrode arrangement, comprising at least one electrical connection line (1) and an electrode component (2, 20) designed as a measuring and holding element, which is coupled to the electrical connection line (1) ,

2. Arrangement according to claim 1, characterized in that the electrode component (2; 20) with at least one attachment opening (4) is formed.

3. Arrangement according to claim 1 or 2, characterized in that the electrode component (2; 20) is formed from an electrically conductive material.

4. Arrangement according to at least one of the preceding claims, characterized in that the electrode component (2) is formed with a loop-shaped electrode portion.

5. Arrangement according to claim 4, characterized in that the loop-shaped electrode section has an outer diameter of between about 1 mm and about 3 mm, preferably between about 1 mm and about 2 mm.

6. Arrangement according to at least one of the preceding claims, characterized in that the electrode component (20) is formed with a hook-shaped electrode portion.

7. Arrangement according to at least one of the preceding claims, characterized in that the electrical connection line (1) is formed of a flexible wire material.

8. Arrangement according to at least one of the preceding claims, characterized in that the electrical connection line (1) is formed with a length of at least about 30cm.

9. Arrangement according to at least one of the preceding claims, characterized in that a total weight for the electrical connection line (1) and the E lektrodenbauteü (2; 20) less than about 50mg, preferably less than about 40mg and more preferably less than about 30mg is.

10. Arrangement according to at least one of the preceding claims, characterized in that the electrode component (2; 20) is formed without adhesive or adhesive.

11. Arrangement according to at least one of the preceding claims, characterized in that the electrical connection line (1) is formed adhesive or adhesive-free.

12. Arrangement according to at least one of the preceding claims, characterized by a disposable article- execution.