WO2013124141A1

WO2013124141A1 - Electrode arrangement

Info

Publication number: WO2013124141A1
Application number: PCT/EP2013/052098
Authority: WO
Inventors: Torsten Strasser; Tobias Peters; Eberhart Zrenner
Original assignee: Eberhard-Karls-Universität Tübingen Universitätsklinikum
Priority date: 2012-02-20
Filing date: 2013-02-01
Publication date: 2013-08-29
Also published as: DE102012101337B4; DE102012101337A1

Abstract

A main body (11) for an electrode arrangement (10) for electrically contacting an animal or human body, comprising at least one main body (11) and a connection line (14) electrically connected to the main body (11), has a superabsorbent polymer (SAP) with an absorption capacity of more than 10 weight units of water per weight unit of SAP. The main body (11) is clamped in a holder (12) on which the connection line (14) is mounted.

Description

electrode assembly

The present invention relates to an electrode assembly for electrical contacting of an animal or human body, with at least one base body and with an electrically connected to the main body or connectable connection line.

An electrode arrangement for contacting the human eye is known from EP 2 083 91 1 B1.

The known electrode arrangement comprises a base body implantable to the eye, to which connecting leads are connected.

Such electrode arrangements are also known elsewhere from the prior art.

They are used for example in ophthalmology to initiate electrical stimulation signals in the eye or derive signals from the eye. In general, the known electrode arrangements are used everywhere in medical technology, where electrical signals must be derived from the human body or electrical stimulation signals must be supplied. However, such electrode arrangements can also be used for technical purposes, for example, to ground in semiconductor laboratories technicians who handle integrated circuits.

As a rule, when using electrode arrangements in medicine, it is necessary to arrange a further counter-electrode next to the stimulation or measuring electrode at another area of the body.

In ophthalmology, it is often necessary in this context to contact the eye with electrodes to interrogate electrical potentials or to electrically stimulate the eye. It is often desirable or even necessary to stimulate or stimulate the eye optically, for example with monochromatic light, in order then to detect the signals generated in the eye.

The term "ophthalmology" in the context of the present invention, both therapeutic and diagnostic methods and investigations in the context of research projects understood. These methods can be performed on the human eye as well as on eyes of animals, especially mammals, especially small mammals.

When such electrode arrangements are brought into contact with the eye or any other part of the human body, in particular the skin, irritation or other disturbing effects may occur at the point of contact between the electrode arrangement and the cornea (cornea of the eye) or the skin Perform effects that make the contact with the electrode assembly as disturbing or unpleasant. This can also lead to undesirable interactions, for example, because the eye dries out or the skin reacts in the contact area with redness or other changes.

In ophthalmology, it is further known that the application of electrodes on the cornea leads to a change in the eye, for example because because of the dryness, the media become cloudy or especially neovascularization occurs in the animal.

Both not only hampers the measurements, but also affects the measurement results.

[0013] In the event that, following an electrophysiological examination in which the electrode arrangement bears against the cornea, the ocular fundus is to be optically detected, for example, turbid media or neovascularizations can obstruct or even make impossible optical detection.

The known electrode arrangements occur in a wide variety of configurations.

[0015] Sagdullaev et al .: Improved contact lens electrode for corneal ERG re- cordance in mice, in Documenta Ophthalmologica 108, pages 181-184, 2004, for example, describe the use of electroretinography electrodes as contact lenses.

[0016] Komaromy et al .: Technical issues in electrodiagnostic recording, in Veterinary Ophthalmology 5, pp. 85-91, 2002, describe various types of electrodes used for electroretinography and in the measurement of optically induced potentials in veterinary medicine. They compare gold-plated contact lens electrodes, gold-plated contact lens electrodes and DTL electrodes for their applicability and effect.

Coupland and Janaky: ERG electrode in pediatric patients: Comparison of DTL fiber, PVA gel, and non-corneal skin electrodes, in Documenta Ophthalmologica 71, pp. 427-433, 1989, compare with DTL electrodes and skin Biopotential electrodes, a polyvinyl alcohol gel-based electrode as described by Honda et al .: New disposable ERG electrode made of anomalous polyvinyl alcohol gel, in Documenta Ophthalmologica 63, pp. 205-207, 1986. The PVA hydrogel has a water content of 80 to 90% and is designed as an elastic electrode plate, which is placed on the cornea. The electrodes deliver stable signals in the ERG and can be chemically sterilized. They cause no damage to the cornea and are discarded after use. The elastic electrode plate has a thickness of 0.3 to 1, 0 mm and can be easily cut into any shapes.

Alba et al .: Novel hydrogel-based EEG electrode, in: IEEE Transactions on Neural Systems and Rehabilitation Engineering 18, pages 415-423, 2010, describe the use of a superabsorbent hydrogel as the skin electrode for EEG applications. The hydrogel can hold 99.2% deionized water or 91% of an electrolyte solution, with the water content remaining high even after 29 hours of air exposure.

To prepare the electrodes, dry polyacrylate samples are placed in an electrolyte bath and left there for 12 hours, so that they absorb themselves completely with liquid. Thereafter, the gels are cut into narrow slices of 3 mm thickness and 10 mm diameter. Along the diameter, a small channel is then inserted into these discs, into which then an Ag / AgCl-electrode is inserted.

[0021] Nyberg et al .: Polymer hydrogel microelectrodes for neural communication, in: Biomedical Micro Devices 4: 1, pages 43-52, 2002, describe microelectrodes of a hydrogel with a conductive polymer used to measure nerve signals.

Hu et al .: Hydrogel Contact Lens for Extended Delivery of Ophthalmic Drugs, in International Journal of Polymer Science 2001, Item ID814163, describes the use of softgel hydrogels used for storage and controlled delivery of medicaments. In contrast, Yatav et al .: Recent trends on hydrogel in human body, in International Journal of Research in Pharmaceutical and Biomedical Sciences 2, pages 442-447, 201 1 describe that the use of hydrogels in contact lenses has disadvantages, which are related to the onset of the lenses, hypoxia, dehydration and eliciting "red eyes".

Sha et al., In Medical Engineering & Physics 30, pages 739-746, 2008, describe the use of thin hydrogel layers under a clinical electrode, to improve the comfort for the patient.

[0025] Green et al .: Conducting polymer-hydrogels for medical electrode appli- cations, in Sei. Technol. Adv. Mater. 1 1, 014107, 2010, describe hydrogels with conductive polymer as the basis for medical electrodes. In these electrodes, the hydrogels improve the mechanical properties of the conductive polymers and serve as a depot for water-soluble, bioactive agents.

US 201 1/01 18655 A1 describes galvanic skin treatment devices comprising substrates with superabsorbent polymers on which electrodes are disposed. The devices should also be applicable to the human or animal eye.

Although the use of various hydrogels as contact lenses and electrodes for medical application are known in this respect, the known electrode applications all have the disadvantage that they are difficult to handle, in particular for use in the electrophysiology of vision, and are manufactured with great individualization they are usually very expensive as well.

Against this background, the present invention seeks to provide an electrode assembly of the type mentioned, which is inexpensive and easy to manufacture, the handling is not a problem and the applied electrode assembly does not burden the human or animal patients. Furthermore, the electrical properties should at least be comparable to those of wire electrodes.

According to the invention, this object is achieved in that the base body has a superabsorbent polymer (SAP), which has a capacity of more than 10 weight units of water per weight unit SAP.

The problem underlying the invention is completely solved in this way.

The insight of the inventors is that made of a SAP base body for electrode assemblies of the type in question here can be used because they are on the one hand easy to handle and mass-market inexpensive available on the market. On the other hand, liquid-saturated SAP base bodies have their own conductivity and a moist surface, so that they provide for large-area and thus good electrical contact, and in particular do not lead to dehydration of the cornea or skin when using or adding tear-film-stabilizing agents.

The superabsorbent polymers used in the invention are special hydrogels based on carbon compounds, in particular of organic materials, which have found wide use in the hygiene sector because of their enormous water absorption capacity.

While hydrogels can be defined as polymaterials that have the property of being able to swell in water and absorb more than 20% water within their structure, superabsorbent polymers (SAP) are capable of deionized water between 10 and 1000 weight units of water per weight unit SAP.

A particular advantage of SAP particles is that they retain their shape during water uptake and swelling. this is the most important practical advantage that SAPs have over other hydrogels; See Zohuriaan-Mehr & Kabiri: Superabsorbent polymer materials: A review, in Iranian Polymer Journal 17, pages 451-477, 2008.

Riccardo®: Water-absorbent polymers: at Patent Survey, in J.M.S. - Rev. Macromol. Chem. Phys. C34 (4), pages 607-662, 1994, and Zohuriaan-Mehr et al .: Advances in non-hygienic applications of superabsorbent hydrogel materials, in: J. Mater. Be. 45, pages 571 1 -5735, 2010, describe various areas of application for SAP materials, including applications in the field of electrical engineering.

Thereafter, SAP materials are already used to protect DC power lines and to eliminate moisture-induced short circuits in such lines. Furthermore, SAP hydrogels are used to reduce grounding resistance in electrical equipment and to combat the effects of water leaks in electric batteries.

The inventors of the present application have now recognized that SAP hydrogels, because of their mechanical stability, their excellent biocompatibility due to their organic base material, and their high liquid absorption capacity, are eminently suitable for forming the body of electrode assemblies used in ophthalmology Query or application of electrical potentials can be used, generally in the medical field for deriving or applying electrical potentials across the skin, and are suitable in the technical field for grounding technicians.

Because the SAP base body in contrast to their dimensions do not or only slightly change their geometric shape in the liquid intake, they can be brought in the "dry" state already in the desired geometric shape, so that post-processing after swelling is not required is when they have reached their intended dimensions or dimensions for the particular application. This is a particular advantage over the past as electrodes used hydrogels. The final dimensions of the body are defined by the dimensions of the dry body and the material used as SAP.

The basic body can thus be provided in the dry state with blind holes or through holes, outside circumferential retaining grooves or flats, which then assume the desired shape and size when swelling, so that they can be used in the manner to be described hereinafter.

The swollen body are mechanically stable so that they can be easily detected with the bare hand and used in appropriate holders that take the body, for example, on a circumferential retaining groove, or have a pin-like projection on which the body with his Blind hole or its through hole is plugged.

In addition, either the end of an electrical lead can be inserted into the blind hole or through hole, so as to connect the electrode formed by the main body itself with other electrical equipment, wherein it is also possible in the blind hole or the through hole, a light source bring in to illuminate the body from the inside or to emit light from the body, for example, in the eye.

This light source may include, for example, one or more light-emitting electrodes (LEDs) or a light guide, is given by a more distant light source monochromatic or multi-colored light in the body and from this then in the eye contacted.

It is particularly preferred if the base body is formed substantially spherical, wherein surface areas of the ball can be flattened or dome-shaped curved inward, so that the ball in this surface area accurately on the cornea of the eye or on a skin surface to be contacted can be applied. In addition, many SAP hydrogels are optically clear in the swollen state, so that they can easily forward or pass monochromatic or multicolored light.

For applications in which optically stimulated, electrical potentials are to be measured, the base body can be arranged in a holder which comprises a spherical electrically conductive holding shell, preferably a metal shell. This spherical metal shell can grasp the spherical base body to more than 50% of its surface, so extend beyond the equator, so that the swollen base body can be easily pressed into the metal shell to hold it. Because the body is slightly elastic, it can be pressed into this spherical metal holder and remains there as long as it maintains its high content of liquid. This swollen state is then retained by the SAP objects for several hours.

The metal shell or the holder are connected to the connecting line, wherein over the large metal surface a very good electrical contact with the base body, ie the actual electrode takes place, which in turn makes contact with the skin or the cornea via the machined surface area.

If the metal shell is additionally mirrored, light introduced into the base body via a light source can be reflected on the metal surface such that this light emerges efficiently on the side of the base body opposite the metal surface and thus, for example, for the optical excitation of the human or animal eye can be used.

Of particular advantage in the new electrode assembly is the completely excluded risk of injury in contact with the cornea, because the main body of SAP hydrogel to well over 99% consists of water, so that it has a certain flexibility, although it has its geometric shape essentially retains. This also makes it possible for the patients to apply such electrodes themselves to their eyes.

Also visually impaired or even blind patients can handle the electrode assembly, because the swollen base body diameter in the range of 10 to 20 mm and are sufficiently stable so that they can be handled by inexperienced users.

In the field of ophthalmology is intensively researched whether the progression of certain eye diseases can be prevented by the stimulation of the eye with electrical impulses or even an improvement can be brought about. This treatment must be regular, and in many cases the patient can also perform the treatment at home.

So far, wire electrodes are used for these purposes, which are inserted into the eyelid; see, for example, WO 201 1/086150 A2.

These manipulations are already problematic for sighted patients, for visually impaired or blind patients, they are carried out only with great effort, the use of wire electrodes in many patients also meets with rejection.

If the new electrode arrangements are now used instead of the wire electrodes in such applications, the patients need only place marble-sized balls on corresponding, usually spectacle-like holding devices or clamp them into these holding devices, in order then to contact the spherical electrodes with the aid of the holding device to bring the cornea. These manipulations meet significantly fewer concerns than the use of wire electrodes.

In addition, because of the certain elasticity of the body even with improper or inexperienced handling a secure electrical contact with the cornea is made. In addition, the new electrode assembly also has advantages against the cost background, because the SAP beads, which come here as a dry body in question, are mass-produced items that are used for example as a water or nutrient storage for cut flowers and potted plants. They are sold, for example, under the name "BlumenkristaH" by Alanfida Germany oHG, Cologne.

In particular for ophthalmology, the present invention provides advantages because complicated, expensive and expensive devices for electroretinographic derivations of the cornea in humans and animals can be replaced by very inexpensive electrode arrangements. It is particularly advantageous that in a single body, so the polymer ball, both the light stimulation and the derivation of electrical potentials can be combined. This is a completely new approach to the electrophysiological examination of the eye.

Not only the use of the expensive previous devices is replaced according to the invention, but also the previous separation between stimulation and electrode is eliminated according to the invention.

It is particularly advantageous that the cornea is protected by maintaining the tear film, which is not possible with the previously known electrodes.

Of particular advantage is also that the cornea or in other applications, the human or animal skin does not come directly in contact with metal electrodes, but that the potentials are passed over the body, so that, for example, no photoelectric effects at the interface between the metal electrode and the skin can occur.

Against this background, the present invention relates to a base body for an electrode assembly for electrically contacting an animal or human body, the at least one base body and one with the main body electrically connected or connectable connecting line, wherein the base body has a superabsorbent polymer (SAP) with a capacity of more than 10 weight units of water per weight unit SAP.

The base body is preferably a spherical, more preferably optically clear base body, wherein more preferably the base body in a surface region has a shape deviating from the spherical shape, preferably flattened or dome-shaped curved inwards.

Spherical bodies are easily storable and transportable in a dry state, they are also available as a mass-produced article. For example, for experiments within the scope of the present invention, the present inventors have used the above-mentioned flower-spiked SAP globules which, after soaking in liquid for about 8 to 10 hours, have about one hundred to one thousand times their volume, the diameter increasing from about 1 mm to 10 to 20 mm.

If the surface area partially deviates from the spherical shape, the spherical electrode can then be easily adapted to the respective shape of the area to be contacted. For example, if the human skin, for example, the forearm to be contacted, the surface area may be flattened, however, if the cornea is to be contacted, the surface area is machined so that it is curved dome-shaped inward, the dome then to the curvature of the Cornea is adapted. This increases the contact area with the cornea.

Since the SAP beads can be processed shaping in the dry state, so also different Kalottenformen can be realized, which are suitable for different sized and / or curved corneal structures.

Further, it is preferred if at least one hole is present in the base body. This hole may be a blind hole or a through hole, it serves, for example, to receive the connecting cable, or to position the base body on a suitable holder or fasten.

Further, it is preferred if the base body has an annular groove extending on its surface.

Here it is advantageous that the main body can be handled well on this outside on the body annularly circumferential groove on the one hand, he slips when gripping not so easy from the fingers as a completely round, completely swollen body, which is because of its moist Surface and minor compressibility may be slightly harder to detect than if a circumferential groove is provided.

This groove also serves to properly position the body when placed on a suitable holder, wherein the holder can also engage in the groove beyond.

In general, it is preferred if the superabsorbent polymer comprises a superabsorbent hydrogel based on carbon compounds, in particular of organic materials, preferably selected from the group: sodium polyacrylate ([-CH ₂ -CH (COONa) -] _n ) and Polyacrylamides (-CH ₂ CHCONH ₂ -).

According to the invention, such SAPs are used for the first time as transparent electrodes which allow light to pass through and / or serve for the dissipation of electrical potentials and / or electrical stimulation.

The polymers can be adapted by suitable processing, modification, addition of, for example, conductive polymers or substances, doping, etc. with respect to the desired properties, so that the main body for the respective application optimal material properties such as absorption behavior, transparency, shape, strength , electrical conductivity, etc. have. Examples these are poly (acrylamide-anilines), polyacrylamides / Cu, poly (acrylamide-pyrroles), and polyacrylates / graphites.

In view of the above, the present invention further includes a holder for the new body, wherein the holder is adapted to pinch the body.

The holder may for example be an annular holder, in which the swollen base body is inserted so that the annular holder comes to rest in the circumferential groove.

In the case of the holder, it is preferred if the connecting line is connected or connectable to it.

The main body itself is electrically conductive and thus serves as an electrode, but he still has to make a good contact with the connecting cable. If the base body is clamped in an electrically conductive holder, then the base body is in electrically conductive connection with this holder over the entire clamping surface. Then either a connection for a connecting line, for example a plug-in connection, or directly the connection line itself can be attached to the holder. In this way, a good electrical transition between the connecting line and the main body is provided.

It is preferred if the holder comprises an electrically conductive, spherical holding cup, which is in contact with the clamped base body.

Here it is advantageous that the holding shell fulfills two functions, on the one hand, it ensures a very large-scale mechanical and thus electrical contact with the main body, so that the electrical contact resistance is very low. On the other hand, the holding shell can include the main body more than hemispherical, so that the main body is pressed into this holding shell and then there so far slips into it until it jammed inside its circumference in the holding cup. It is particularly preferred if the holding shell is mirrored on its side facing the clamped base body.

Here it is advantageous that the holding cup is not only provided for mechanical holding and electrical contacting of the base body, it can also ensure that radiated light into the base body for reflection of the eye by reflection suitably reflected in the eye becomes.

Further, it is preferred if the holder comprises a light source, which are further preferably associated with optical elements that direct light rays from the light source into the body.

Here it is advantageous that the base body can be configured as a pure ball lens, so no shaping processing must be subjected, because the optical excitation is provided on the holder, and the base body with respect to the coupling of the light rays optimized in the eye can be. In addition, if the base body is suitably modified, preferably dome-shaped curved inwards, the contact area to the cornea increases. This is especially true if the curvature of the calotte is adapted to the curvature of the cornea.

The new electrode arrangement for electrical contacting of an animal or human body thus comprises at least the new main body and preferably also the new holder.

In this case, the electrical connection line is preferably provided in a hole provided in the base body, wherein more preferably a light source is provided in a hole provided in the base body.

On the other hand, while the base body can be electrically connected to the connection line by interposing the holder, it is also possible to provide a blind hole or a through hole in the base body into which one end of the connection line is inserted. Over the entire inner surface of the Hole is the body then in electrically conductive connection with the connecting cable.

If the new electrode arrangement is to be used to detect optically triggered in the eye electrical signals, also for the introduction of the excitation light of the main body can be used. For this purpose, a hole or another hole is provided in it, in which either one or more light emitting diodes (LEDs) or a light guide is inserted, the other end is connected to a light source, such as a monochromatic light source.

Because the body is optically clear, it passes light irradiated through this hole without breaking it. If the base body is clamped in the holder with the spherical holding shell, which is also mirrored on its inside, the light entering the base body is reflected by this spherical surface and thus reaches the eye to be excited with high yield.

Another possibility of optical stimulation is to arrange the light source not in the main body but at a suitable distance behind the main body, so that it serves as a ball lens, whereby the eye is illuminated evenly. This arrangement can be combined with the mirrored holder described above.

The main body can therefore also be used as an optical lens, wherein it is not absolutely necessary that it also acts as an electrode at the same time.

The invention therefore also relates to an optical lens arrangement which has a main body made of SAP. The properties and characteristics of the main body and of the holder which clamps it in are those which have already been described for use as an electrode. From DE 690 33 694 T2, an optical lens arrangement for coupling light beams into the eye is already known, which comprises a shell of polymethyl methacrylate or another sterilizable material which can be applied to the cornea of the eye. This shell is followed by an optical section with a converging lens through which light is directed onto or into the eye.

In the case of the new electrode arrangement or lens arrangement, it is then preferred if the base body is saturated with an electrically conductive liquid.

It is possible to saturate the body either with water or with an electrolyte, so as to provide a corresponding conductivity of the body.

Furthermore, active substances can be added to the liquid which, for example, ensure the retention of the tear film in order to avoid irritation of the cornea.

In the context of the present invention, "active substances" are understood as substances which influence the state of the cornea in a physiological or biochemical manner, in particular protect or stabilize, or facilitate the examination in the case of an anesthetic for the patient.

Against this background, the present invention also relates to a kit with at least one new base body and at least one storage vessel with a preferably electrically conductive liquid, to which preferably at least one active substance has been added.

In particular, for applications in the private sector, so in the use of stimulating the eye with electrical pulses, it may be helpful if the user is provided a kit in which several basic body are in a dry state, so that they are stored longer term can. If the kit further contains at least one storage vessel with the preferably electrically conductive liquid, the user only has to insert one or more base bodies into the storage vessel as needed and let the basic bodies swell overnight, for example, until they have reached their absorbed form. Thereafter, the user can remove the main body from the storage vessel and insert it into the holder, which may for example be part of a pair of glasses, as described in the above-mentioned WO 201 1/086150 A2 for wire-shaped electrodes.

The provision of base bodies in the dry state and storage vessels, which are already filled with the preferably electrically conductive liquid, but not only has handling aspects. It is also advantageous that the conductive liquid does not have to be procured separately and separate storage vessels must be provided for this at home. Another advantage is the ease of use and ensuring hygienic boundary conditions and the use of the appropriate liquid. Further, the liquid may be added active substances that improve the use of the swollen base body as an electrode and / or lens or at least support.

Against this background, the present invention further relates to a method for producing the new electrode assembly comprising the steps of: a) providing the new body, b) immersing the body in an electrically conductive liquid for a predetermined period of time, preferably until the body with Liquid has soaked, and c) clamping the body in a holder, preferably in the new holder.

In a further development, the method comprises the further step: d) insertion of the connecting line in a provided in the base hole.

In a further development, the method also includes the step: e) insertion of a light source in a provided in the base body

Hole.

Further advantages will be apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Embodiments of the invention are illustrated in the drawings and will be explained in more detail in the following description. Show it:

Figure 1 is a side view of a first embodiment of the new electrode assembly, with cut holder.

FIG. 2 shows a view similar to FIG. 1 of a second embodiment of the new electrode arrangement; FIG.

Fig. 3 in a representation like Figure 1 shows a third embodiment of the new electrode assembly.

4 shows a fourth exemplary embodiment of the new electrode arrangement;

5 shows an embodiment of the new lens arrangement; Fig. 6 is a typical evaluation of an ERG curve; and

7 shows a diagram of superimposed ERG curves of measurements on both eyes of a rat with an electrode according to the invention or with a gold ring electrode.

In Fig. 1, an electrode assembly 10 is shown in a schematic side view and not to scale, comprising a base body 1 1, which is clamped in a here annularly shaped holder 12.

The main body 1 1 is a substantially spherical body, it consists of a superabsorbent polymer SAP and has been soaked with a conductive liquid 13, preferably water, physiological saline solution or other, with respect to their conductivity optimized liquid. This liquid may be accompanied by active substances to protect the cornea.

The main body 1 1 has a diameter D of 1 1 mm, in the dry state was its diameter D just once 1 mm. Depending on the application, the final diameter D may be different.

The electrode assembly 10 is connected to a connecting line 14, which is inserted with its stripped end 14a in a blind hole 15, which was centrally introduced into the base body 1 1, when he was still in the dry state.

The annular holder 12 has an annular bead 16 which engages in an annular groove 17 which runs along the equator 30 around the spherical base 1 1 around.

In this way, the main body can be clamped after swelling in the holder 12 by being inserted, for example, from the left or from the right into the ring. The main body 1 1 expresses something together and expands again when groove 17 and ring 16 are opposite each other. At its right in Fig. 1 surface area 18, which is remote from the hole 15, the base body 1 1 is provided with an inwardly curved cap 19, which is mounted in its curvature to the shape of the cornea C of the eye A. with which the main body 1 1 should come into contact.

On the holder 12, a fastening bolt 20 is arranged, which is shown only schematically in Fig. 1.

By way of the fastening bolt 20, the holder 12 can be fastened, for example, to a spectacle-like frame, as shown in the aforementioned WO 201 1/086150 A2.

When putting on a pair of spectacles, which is provided with two electrode assemblies 10 as shown in FIG. 1, then enter the dome-shaped recesses 19 in contact with the cornea, so that either the cornea via the connecting line 14 is electrically stimulated or electrical signals from the cornea can be tapped.

Because the base body 1 1 is slightly elastic on the one hand, on the other hand has a moisture film on its surface, bringing the electrode assembly 10 with the cornea is neither unpleasant nor stressful, in addition, the tear film is maintained, so that the subjects did not experience any adverse effects.

In FIG. 2, as in a representation in FIG. 1, a second exemplary embodiment of the electrode arrangement 10 is shown, in which the surface area 18 is flattened, so that here a planar contact surface 21 is formed.

The holder 12 has in this embodiment, a spherical holding shell 22, which comprises the spherical base body 1 1 hemispherical. In the hemispherical holding shell 12, in turn, a peripheral bead 16 is provided on the inside, which cooperates with the encircling ring 17. Here, the fastening bolt 20 extends transversely to the annular groove

17th

Over the entire inner side 22a of the holding shell 22, the base body 1 1 is now in electrical contact with the holder 12, so that here a very good contact resistance is realized.

The supply line 14 is connected via a plug connection 23 with the holder 12.

FIG. 3 shows in a representation like FIG. 1 and FIG. 2 a third exemplary embodiment of the invention, in which the surface area 18 is again designed as a dome 19.

The holder 12 again has a holding shell 22, which now comprises the spherical base body 1 1 more than hemispherical, so beyond the equator 30, so that the angular range 24, to which the main body 1 1 to the right from the holding shell 22nd protruding, is less than 180 °.

In the base body 1 1 here an obliquely from the top right into the center of the body 1 1 extending blind hole 25 is provided, into which a light guide 26 is inserted, are guided by the light rays indicated at 27 in the base body 1 1.

The holding shell 22 is mirrored on its directed to the base body 1 1 surface 22a, so that the light rays 27, which can propagate freely in the clear base 1 1, reflected at the spherical surface 22a and immediately to the right from the main body 1 1 out into the eye, not shown for reasons of clarity. 4, a fourth embodiment of the new electrode assembly is shown, in which the holder 12 in turn has a holding shell 22, from which the depressed base body 1 1 protrudes to less than 180 ° to the right.

In contrast to the embodiment of FIG. 3, the fastening bolt 22 is here pivoted by 90 °, so that it extends in the equatorial plane, ie parallel to the calotte 19.

Transverse to the fastening bolt 20 and thus to the equator 30, a through hole 28 in the base body 1 1 is provided. A corresponding hole 29 is also located in the holder 12.

Through the hole 29, the light guide 26 is inserted into the through hole 28, wherein the light guide lies with its front tip 31 approximately in the region of the equator 30.

From the light guide 26 again emerge light rays 27, which widen conically according to the numerical aperture of the light guide 26 and penetrate into the eye.

In Fig. 5, an embodiment of a lens assembly 32 is shown in which a cornea C of the eye A contacting main body 1 1 is formed globally spherical. The main body 1 1, which corresponds to the base body described above, is clamped in an open front end 33 of a tubular holder 34 in which a light source 35 is arranged, which emits light rays 36, which may be monochromatic or multi-colored.

In this case, inside the holder 34, a lens 37 may be arranged. Further, the holder 34 may have a reflector 39 at its rear end 38. Lens 37 and reflector 39 are optical elements that assist in coupling the light beams 36 into the eye A. The Grundkörperl 1 acts as a ball lens that effectively couples the light beams 36 in the eye A and at the same time can derive electrical potentials from the cornea C. The basic body can be shaped to meet certain geometric requirements.

On the holder 34, a connector 23 may be provided for the connection line 14, when the body is not only to serve as a lens but also at the same time as an electrode.

Initial experiments by the inventors with such electrode arrangements 10, which contained as base 1 1 "BlumenkristaH" SAP beads which had been soaked with physiological saline for 12 hours, have shown that they yield similarly good results in ERG measurements how to deliver gold ring electrodes.

Fig. 6 shows a typical evaluation of an ERG curve by determining the a and b waves with latency and amplitude. The amplitude of the b-wave is determined relative to the amplitude of the a-wave.

Fig. 7 shows the result of an ERG measurement on a rat from a standard flash (3.0 photopic cd ^* s / m ² ) for measuring the response of cones and rods. The experimental set-up comprised an electrode according to the invention in the left eye and a gold ring electrode in the right eye. The curves show the averaging of four or seven individual measurements.

[00139] The table below summarizes the results. Thereafter, the amplitudes in the previously tested inventive electrode arrangements are slightly lower than in the gold ring electrodes, while the latencies correspond to each other. Mean value (standard deviation)

Electrode N a-wave Amplitude a-wave Latency b-wave Amplitude b-wave Latency

Gold ring 4 -288,30μν 13,9ms 707,58μν 74,0ms

(± 101,02μν) (± 0,9ms) (± 214,82μν) (± 4,0ms) erfin7 -193,80μν 14,2ms 452,35μν 75,0ms dungs (± 37,39μΥ) (± l, 2ms ) (± 121.31μΥ) (± 4, 5ms) according to

Claims

claims

1 . Basic body for an electrode arrangement (10) for electrically contacting an animal or human body (A, C), wherein the electrode arrangement comprises at least the main body (1 1) and a connection line (14) electrically connected or connectable to the main body, characterized in that the base body (1 1) has a superabsorbent polymer (SAP) with a capacity of more than 10 weight units of water per weight unit SAP.

2. Basic body according to claim 1, characterized in that it is substantially spherical.

3. Basic body according to claim 1 or 2, characterized in that it is an optically clear base body (1 1).

4. Basic body according to one of claims 1 to 3, characterized in that the base body (1 1) in a surface region (18) has a shape deviating from the spherical shape, preferably flattened (21) or dome-shaped (19) is curved inwards.

5. Basic body according to one of claims 1 to 4, characterized in that it comprises a circumferential on its surface, annular groove (17).

6. Basic body according to one of claims 1 to 5, characterized in that in the base body (1 1) at least one hole (15, 25, 28) is present.

7. Basic body according to one of claims 1 to 6, characterized in that the superabsorbent polymer comprises a superabsorbent hydrogel based on carbon compounds, in particular of organic materials, vorvor is preferably selected from the group sodium polyacrylate ([-CH ₂ - CH (COONa) -] _n ) and polyacrylamides (-CH ₂ CHCONH ₂ -).

8. Holder for the base body (1 1) according to one of claims 1 to 7, characterized in that it is adapted to clamp the base body (1 1).

9. Holder according to claim 8, characterized in that connected to it, the connecting line (14) or is connectable.

10. Holder according to claim 8 or 9, characterized in that it comprises an electrically conductive, spherical holding shell (22) which is in contact with the clamped base body (1 1).

1 1. Holder according to claim 10, characterized in that the holding shell (22) is mirrored on its the clamped base body (1 1) side facing.

12. Holder according to claim 8 or 9, characterized in that it comprises a light source (35).

13. Holder according to claim 12, characterized in that the light source (35) optical elements (37, 39) are associated, the light beams (36) from the light source (35) in the main body (1 1) conduct.

14. An electrode arrangement for electrical contacting of an animal or human body (A, C), which comprises at least one base body (1 1) according to one of claims 1 to 7.

15. An electrode assembly according to claim 14, characterized in that it comprises the holder (12) according to any one of claims 8 to 13.

16. An electrode arrangement according to claim 14 or 15, characterized in that in a in the base body (1 1) provided hole (15), the electrical connection line (14) is provided.

17. Electrode arrangement according to one of claims 14 to 16, characterized in that in a provided in the base body hole (25, 28) is provided a light source (26).

18. Electrode arrangement according to one of claims 14 to 17, characterized in that the base body (1 1) is saturated with an electrically conductive liquid (13).

19. Kit with at least one main body according to one of claims 1 to 7 and with at least one storage vessel with a preferably electrically conductive liquid.

20. A method for producing an electrode assembly (10) according to any one of claims 14 to 18, comprising the steps of: a) providing a base body (1 1) according to any one of claims 1 to 7, b) immersing the base body (1 1) in one electrically conductive liquid (13) for a predetermined period of time, preferably until the main body (1 1) has become saturated with liquid, c) clamping the base body (1 1) in a holder, preferably in the holder (12) according to one of claims 8 to 13.

21. Method according to claim 20, characterized by the further step: d) insertion of the connection line (14) into a hole (15) provided in the base body (11).

22. The method according to claim 20 or 21, characterized by the further step: e) insertion of a light source (26) in a in the base body (1 1) provided hole (25, 28).

A lens assembly for coupling light beams (36) into an eye (A), comprising a body having a superabsorbent polymer (SAP) having a capacity of more than 10 weight units of water per unit weight of SAP.

24. A lens arrangement according to claim 23, wherein the base body has the features of at least one of claims 2 to 7.

25. A lens arrangement according to claim 23 or 24, comprising a holder for the base body, wherein the holder has the features of at least one of claims 8 to 13.