DE29517060U1 - Stimulation device - Google Patents

Description

Dipl.-Phys. Dr. H.-H. Stoffregen . · · · Il I .*..:···. Page 1

Patent Attorney-European Patent Attorney " ··· ··· ····*·..*

Wilhelm Waskönig
Sacramento Street, 15

E-04720 Aguadulce (Almería)
Spain

Description Stimulation device

The invention relates to a stimulation device, in particular intended for stimulation of vascular nerve sheaths, comprising a voltage source and first and second electrodes connected to the latter, which can be brought into conductive connection via a body, of which a first electrode is a section, in particular on the tip side, of a cannula to be inserted into the area of the body to be stimulated, with an opening for injecting an anesthetic, and the second electrode runs at a distance from this.

According to the current state of the art, so-called unipolar stimulation is carried out in such a way that the cathode in the form of the cannula tip is positioned at a point on the body where nerve pathways are being searched for and the counter electrode is attached at a distance from this to another part of the body. The cannula is normally the cathode and the other electrode is the anode.

The arrangement of the electrodes results in a relatively large distance between them, so that it cannot be determined with sufficient certainty whether the tip of the cannula is actually located at the location where an anesthetic is to be injected later. The reason for this is that it is not possible to precisely check the tissue between the electrodes, which can lead to a loss of performance during stimulation.

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DipL-Phys. Dr. H.-H. Material regen . : : · ; · J .*..:···. Page 2

Patent Attorney-European Patent Attorney ** · ··" ··"...*

So-called bipolar instruments for simulating peripheral nerves are also said to be known, in which a needle forming an electrode is surrounded by an outer cannula. The needle's sole task is to search for peripheral nerve pathways.

The present invention is based on the problem of developing a stimulation device of the type mentioned at the beginning in such a way that body regions, in particular vascular nerve sheaths, can be stimulated with high precision and with simple measures in order to subsequently inject a required anesthetic.

According to the invention, the problem is essentially solved in that the second electrode is a section of a stylet running inside the cannula or of an outer cannula surrounding the cannula, which is electrically insulated from the cannula outside the section forming the second electrode.

The injection cannula can be made of metal and electrically insulated on the outside by a coating such as powder coating, except for an area that forms the first electrode. The stylet can also be made of electrically conductive material and electrically insulated on the outside by, for example, powder coating, with the insulation being removed in the area that forms the second electrode. Furthermore, a connection for an electrical cable is provided at the end, which can be connected to the voltage source or an electrical circuit connected to it, which essentially comprises a current limiter.

If necessary, the cannula can also be insulated on the inside to ensure that there is no electrically conductive connection between the electrode extending from the stylet and the cannula without there being tissue between the electrodes.

The electrical connection for the cannula itself is made via a holder that can be passed through the stylet and can be made of an electrically conductive material such as brass.

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According to a further development of the invention that is worth highlighting, it is provided that the passage intended for the stylet can be closed in order to be able to introduce anesthetic under high pressure via the passage after the stylet has been removed.

Due to the teaching of the invention, there is an extremely small distance between the electrodes in the immediate vicinity of the location where the anesthesia is to take place. This ensures that tissue-related power losses, which can lead to incorrect localization, are excluded.

In particular, the stylet or the area forming the second electrode should be designed as a cathode, whereby nerve stimulation occurs directly where the anesthetic exits the cannula. If necessary, the cathode and anode can of course also be exchanged.

If the second electrode is formed by a section of the outer cannula or indwelling cannula, a further development of the invention provides that the section forming the second electrode runs on the outside of the cannula in the area opposite to the opening of the injection cannula.

Regardless of the course of the second electrode, the distance between the section of the outer cannula forming the second electrode to the opening of the injection cannula should be greater than to the first electrode.

In particular, it is provided that the outer cannula or indwelling cannula is made of plastic, in which an electrically conductive connection such as an embedded or molded wire runs to the section forming the second electrode. The section of the outer cannula forming the second electrode can be the anode.

The distance between the electrodes should preferably be less than 1 cm, which, as mentioned, largely excludes losses due to body resistance, so that the otherwise required complex and expensive circuitry stimulators are not needed. Instead, a simple electrical component is required, which essentially only has a current limiter in addition to a battery.

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Dipl.-Phys. Dr. H.-H. Stoffregen

Patent Attorney-European Patent Attorney

zer includes.

Due to the simple and therefore cost-effective design of the stimulation device, it can be thrown away after a single use.

A particularly noteworthy, inventive design of a stimulation device, in particular intended for the stimulation of vascular nerve sheaths, comprising a voltage source and first and second electrodes connected to it that can be brought into conductive connection via a body, of which a first electrode is a section, in particular on the tip side, of a cannula to be inserted into the stimulating area of the body with an opening for injecting an anesthetic and the second electrode runs at a distance from this, is characterized in that the cannula is made of metal and is electrically insulated on the outside by a coating except for an area that forms the first electrode, and that a conductive connection arranged on the outside of the cannula ends at a distance from the first electrode, which forms the second electrode.

The teaching according to the invention allows the cannula itself to be provided with the first and second electrodes using simple measures, whereby it is only necessary that the cannula is coated with a coating material such as polyester. The cannula is then exposed in the area of the tip or remains covered during coating in order to form the first electrode. The second electrode is then applied by vapor deposition of an electrical connection such as a conductor track on the outside of the coated cannula, whereby the distance between the end of the electrically conductive connection and the first electrode can be in the range of approximately 0.8 cm. Of course, the electrically conductive connection, which can correspond to a conductor track of printed circuits, should run on the side of the cannula that is remote from its opening.

Further details, advantages and features of the invention emerge not only from the claims, the features derived therefrom - individually and/or in combination - but also from the following description of a preferred embodiment shown in the drawing.

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Patent Attorney-European Patent Attorney

Show it:

Fig. 1 is a schematic diagram of a first embodiment of a stimulation

furnishings,

Fig. 2 a schematic diagram of an injection cannula with arranged in it

Mandrin,

Fig. 3 a preferred embodiment of a cannula with stylet in the outlet

cut,

Fig. 4 shows another embodiment of a stimulation device,

Fig. 5 a first cannula with externally applied conductor and

Fig. 6 a second cannula with a conductor attached to the outside.

In Fig. 1, a stimulation device is shown in principle, particularly intended for stimulation of vascular nerve sheaths. The stimulation device comprises a cannula (10) which extends from a handle (12). The handle (12), which can be made of plastic or metal such as brass, has an electrical connection (14) which leads via a cable (16) and a socket (18) to an electronic component which can essentially comprising a battery and a current limiter. In the axial direction of the cannula (10), the handle is penetrated by a passage (20) which merges into an attachment (22) through which a stylet (24) can be pushed into the cannula (10) or onto which a tube (26) can be pushed, through which an anesthetic can be supplied.

The stylet (24) itself can be connected to a connector (not shown) which leads to the electronic component (also not shown).

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A basic structure of a possible embodiment of the stimulation device according to Fig. 1 can be seen in Fig. 2. The injection cannula (10) can be coated both inside and outside. In the area of its tip (30) a point-shaped area (32) is then not insulated, which acts as the first electrode, preferably as an anode. The cannula, which otherwise consists of metal, can then be connected to the electronic component via the cable (16).

The stylet (24) extends inside the injection cannula (10), which is insulated on the outside with the exception of an area (40). When the stylet (24) is properly inserted into the cannula (10), the area (40) runs in the area of a preferably lateral opening (28) of the cannula (10). The non-electrically insulated area (40) has the function of the second electrode such as cathode. If the stylet (24) is made of electrically conductive material and is insulated on the outside, it is only necessary to electrically connect the stylet (24) to the electronic component. If the stylet (24) is made of electrically insulating material, an electrical connection must run to the second electrode (40).

Another preferred embodiment of a cannula/stylet arrangement can be seen in Fig. 3. As Fig. 3 shows, the cannula (10) also has a lateral opening (28) which can be closed by the stylet (24) when it is inserted.

The cannula (10) can be made of metal and is electrically insulated on the outside by, for example, a 50 μιη thick layer, except for an area (32) located in the area of the tip (30) and forming a first electrode. The coating (30) itself can be produced by powder coating. ,

Accordingly, the stylet (24) is electrically insulated from the inner wall of the cannula (10). For this purpose, the stylet (24) can also have a coating (36) on the outside, which is, however, removed in the front section (38), namely in an area (40) that is designed as a second electrode and runs within the opening (28) when the stylet (24) is inserted into the cannula (10). The second electrode (40) is thus electrically isolated from the cannula (10). An electrically conductive

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The connection between the stylet (24) and the cannula (10) can only be made between the electrodes (34) and (40) via the body tissue in which the cannula (10) is inserted.

Due to the small distance between the electrodes (34) and (40), there is only a small loss of power due to the tissue layer running between them. This in turn means that the location where an anesthetic is to be injected can be stimulated very precisely. The electrode (40) of the stylet (24) is preferably designed as a cathode, so that nerve stimulation takes place directly at the location where the anesthetic exits the cannula (10) when the stylet (24) is removed.

Of course, it must be ensured that, if the cannula (10) is not insulated on the inside, no conductive connection is formed between the electrode (40) and the cannula (10) outside the electrode (32).

If the cannula (10) and the stylet (24) are preferably made of electrical material such as metal and are electrically insulated on the outside or inside except for the area of the electrodes (34) and (40) by powder coating, then it is of course also possible to make the cannula (10) and/or the stylet (24) from electrically insulating material such as plastic or ceramic. In this case, however, it is necessary that electrical lines are led to the locations of the electrodes (34), (40) by, for example, vapor deposition. However, after the formation of the electrodes (34), (40), the electrical lines must then be covered again with electrically insulating material.

Fig. 4 shows another preferred embodiment of an injection cannula (10) that is to be used for a stimulation device. As in Figs. 1 to 3, the cannula (10) has a dual function, i.e. it serves as a "search needle" for peripheral nerves on the one hand and as an injection needle on the other.

Deviating from the embodiment of Fig. 1 to 3, the second electrode is not formed by a stylet, but by an indwelling cannula (42) which

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Cannula (10) surrounds the outside. The indwelling cannula (42) is made of plastic and has, in the area remote from the side opening (28), an area (44) that forms the second electrode, which can be the anode. The dimensions of the cannula (10) or the extension of the indwelling cannula (42) along the outside surface of the cannula (10) and the location of the first electrode (34) are selected such that the distance between the electrodes (34), (44) is smaller than the distance between the electrode (44) and the side opening or the eye (28), unless the cannula (10) is also designed to be electrically insulated on the inside.

Since the indwelling cannula (42) is preferably made of plastic, an electrical connection to the electrode (44) must run within the indwelling cannula (42). This can be done by a wire (46) that is embedded in the indwelling cannula (40) or injected into it.

In Fig. 5 and 6, purely by way of example, two cannulas (48), (50) are shown which have a ground tip (Fig. 5) or a pencil point (Fig. 6). Separately, the respective cannula (48), (50) is coated on the outside with electrically insulating material such as polyester, whereby the coating (60, 62) is exposed in the area of the respective tip (52) or (54) of the cannula (48), (50), so that a first electrode (56) or (58) is available. In the cannula (48) with a ground tip, the first electrode (56) should act as a cathode and in the cannula (50) with a pencil point, the first electrode (56) should act as an anode. On the outside, i.e. on the respective coating (60) or (62) of the cannula (48) or (50), an electrically conductive strip such as a conductor track (64), (66) is applied in the longitudinal direction of the respective cannula (48), (50), e.g. by vapor deposition, whereby the conductor track (64), (66) ends e.g. at a distance of approximately 0.8 cm from the tip of the cannula (48), (50), i.e. the electrode (56) or (58). The electrical conductor track (64), (66) thus acts in its end region (68), (70) as a second electrode, which should be the anode for the cannula (48) and the cathode for the cannula (50).

As Fig. 5 and 6 further illustrate, the conductor tracks (64), (66) run on the outer sides facing away from the openings (72), (74) of the cannulas (48), (52).

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Claims (1)

Dipl.-Phys. Dr. H.-H. Stoffregen "'··* Page 1 Patent Attorney-European Patent Attorney Wilhelm Waskönig
Sacramento Street, 15 E-04720 Aguadulce (Almería)
Spain Expectations Stimulation device 1. Stimulation device, in particular intended for the stimulation of vascular nerve sheaths, comprising a voltage source and first and second electrodes connected to it that can be brought into conductive connection via a body (28, 34), of which a first electrode is a section, in particular on the tip side of a cannula (10) to be inserted into the area of the body to be stimulated, with an opening (20) for injecting an anesthetic and the second electrode runs at a distance therefrom, characterized, that the second electrode (40, 44) is a section of a stylet (24) running inside the cannula (10) or of an outer cannula (42) surrounding the cannula, which is electrically insulated from the cannula outside the section forming the second electrode. 2. Stimulation device according to claim 1,
characterized, that the cannula (10) is made of metal and is electrically insulated on the outside by a coating such as powder coating (30) except for an area (34) forming the first electrode. 3. Stimulation device according to claim 1 or 2,
characterized, 27 October 1995-35440A/gi Dipl.-Phys. Dr. H.-H. Stoffregen ** ·· ··· _{page 2} Patent Attorney-European Patent Attorney that the cannula (10) is electrically insulated both inside and outside by a coating such as powder coating (30) except for an area (34) forming the first electrode. 4. Stimulation device according to at least one of the preceding claims, characterized in that that the section of the outer cannula (42) forming the second electrode (44) runs on the outside of the cannula opposite the opening (28) of the inner cannula (10). 5. Stimulation device according to at least one of the preceding claims, characterized in that that the distance between the section of the outer cannula (42) forming the second electrode (44) to the opening (28) of the injection cannula (10) is greater than to the first electrode (34). 6. Stimulation device according to at least one of the preceding claims, characterized in that that the outer cannula (42) or indwelling cannula is made of plastic, in which an electrically conductive connection such as embedded or injected wire (46) runs to the section forming the second electrode (44). 7. Stimulation device according to at least one of the preceding claims, characterized in that that the portion of the outer cannula (42) forming the second electrode (44) is anode. 8. Stimulation device according to claim 1 or 2,
characterized, that the cannula (10) is preferably electrically conductive by a handle (12) 27 October 1995-35440A/gi Dipl.-Phys. Dr. H.-H. Stoffregen *'* ··*···' Page 3 Patent Attorney-European Patent Attorney made of e.g. brass or a plastic handle, which has a preferably closable passage (20) for the stylet. 9. Stimulation device according to at least one of the preceding claims, characterized in that the mandrel (24) consists of metal and is electrically insulated on the outside by a coating (36) such as powder coating, wherein the insulation is removed in the region forming the second electrode (40). 10. Stimulation device according to at least one of the preceding claims, characterized in that that between the first electrode (34) and the second electrode (40) there is a distance d with preferably d < lern. 11. Stimulation device according to at least one of the preceding claims, characterized in that that the second electrode (40) formed by the mandrin (24) is the cathode. 12. Stimulation device according to at least one of the preceding claims, characterized in that the stylet (24) consists of electrically insulating material such as plastic or ceramic and has the second electrode (40) in its area that can be aligned with the opening (28) of the cannula (10). 13. Stimulation device according to at least one of the preceding claims, characterized in that that the cannula (10) consists of electrically insulating material such as plastic or ceramic and has the first electrode (34) in the region of its tip (32). 27 October 1995-35440A/gi DipL-Phys. Dr. H.-H. Stoffregen Patent Attorney-European Patent Attorney 14. Stimulation device, in particular intended for the stimulation of vascular nerve sheaths, comprising a voltage source and first and second electrodes connected to it that can be brought into conductive connection via a body (56, 58, 64, 66), of which a first electrode is a section, in particular on the tip side, of a cannula (48, 50) to be inserted into the area of the body to be stimulated, with an opening (72, 74) for injecting an anesthetic and the second electrode runs at a distance therefrom, characterized, that the cannula (48, 50) consists of metal and is electrically insulated on the outside by a coating (60, 62) except for an area forming the first electrode (56, 58) and that a conductive connection (64, 66) arranged on the outside of the cannula ends at a distance from the first electrode and forms the second electrode. 15. Stimulation device according to at least one of the preceding claims, characterized in that that the conductive connection such as conductor track (64, 66) is vapor-deposited. 16. Stimulation device according to at least one of the preceding claims, characterized in that that the conductive connection (64, 66) is covered by electrically insulating material except for the region forming the second electrode. 27 October 1995-35440A/gi