WO1997015347A1

WO1997015347A1 - Stimulation device

Info

Publication number: WO1997015347A1
Application number: PCT/EP1996/004673
Authority: WO
Inventors: Wilhelm WASKÖNIG
Original assignee: Waskoenig Wilhelm
Priority date: 1995-10-27
Filing date: 1996-10-26
Publication date: 1997-05-01
Also published as: DE29517060U1; EP0957976A1

Abstract

The invention concerns a stimulation device, in particular for stimulating vesicular nerve sheaths or for use in the para-medullary region. The device comprises a voltage source and first and second electrodes which are connected to the voltage source and can be brought into conductive contact via a body. A first electrode is a pointed section (14) of a cannula (12) which is to be brought into the body region to be stimulated and has an aperture for the injection of drugs such as anaesthetics. The second electrode is a conductive connection which is disposed externally on the cannula at a spacing from the first electrode.

Description

description

Stimulation device

The invention relates to a stimulation device, in particular intended for the stimulation of vascular nerve sheaths or in the paramedular area, comprising a voltage source and connected to it first and second electrodes which can be brought into conductive connection via a body, of which a first electrode is a section of a tip in particular is in the injection device to be stimulated, such as a cannula with an opening for injecting pharmaceuticals such as anesthetics, and the second electrode runs at a distance from it.

According to the state of the art, a so-called unipolar stimulation takes place in such a way that the cathode is positioned in the form of the cannula tip at a body point in which nerve tracts are sought and the counterelectrode is attached to another part of the body at a distance from it. The cannula is normally cathode and the other electrode is anode. Due to the arrangement of the electrodes, there is a relatively large distance between them, so that it cannot be determined with sufficient certainty whether the tip of the cannula is actually at the location where an anesthetic is to be injected later Checking of the tissue existing between the electrodes can take place, which can lead to loss of performance during the stimulation

So-called bipolar instruments for the stimulation of peripheral nerves are also known, in which a needle forming an electrode is surrounded by an outer cannula. The needle's sole purpose is to search for peαphere nerve pathways

In order to ensure a defined distance between the first and the second electrode, according to DE 86 04 742 U1, a bipolar electrode for generating a restricted electric field is suggested in order to find neutral structures precisely, with the possibility of simultaneous injection of pharmaceuticals the bipolar electrode is designed as a cannula, within which the electrodes isolated from one another run

A neuro electrode according to DE 36 02 219 AI has a first electrode at a front end and at a distance from it a second electrode, each of which is led to the outside via electrical lines and is connected there with connectors. The neuroelectrode itself is provided with a spool channel, which has radial openings through which liquid can be fed to the vascular nerve sheath with little pressure. If it is designed as a catheter, the bipolar neuroelectrode can preferably also be inserted into the EpiduraL / Spinal- be pushed forward

The present invention is based on the problem of developing a stimulation device of the type mentioned at the outset in such a way that it is very precise and simple measures can be used to stimulate areas of the body, in particular vascular sheaths or in paramedular areas, in order to subsequently inject necessary pharmaceuticals such as anesthetics.

According to the invention, the problem is essentially solved in that the injection device in the form of a cannula is made of metal and is electrically insulated on the outside by a coating except for an area forming the first electrode, and in that a distance from the first electrode is on the outside of the cannula arranged conductive connection that forms the second electrode.

By means of the teaching according to the invention, the cannula itself can be provided with the first and second electrodes with simple measures, it only being necessary for the cannula to be 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, for example, by vapor deposition of an electrical conductor such as a conductor track on the outside of the coated cannula, it being possible for the distance between the end of the electrically conductive connection and the first electrode to 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 lies opposite the opening.

On the basis of the teaching according to the invention, there is an extremely small distance between the electrodes in the immediate vicinity of the location at which, for example, anesthesia is to take place. This ensures that tissue-related performance losses that can lead to incorrect location are excluded.

In particular, a stimulation device of the type mentioned at the outset is characterized in that the injection device is an inner cannula or a catheter which or which is surrounded by an outer or indwelling cannula, the second electrode starting from the outer cannula or inner cannula or the catheter.

If the injection device is a catheter, according to a design to be emphasized, it has at least one lateral opening and is closed in its tip, the tip being designed as a first electrode or the first electrode being embedded in the tip. The first electrode of the catheter can preferably be connected to the voltage source via a conductor, such as wire, which may run inside the catheter or in its wall. There is also the possibility of providing the second electrode on the outside of the catheter in a manner which is proposed on the basis of the cannula designed according to the invention.

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 on the outside of the cannula preferably runs in the opposite region to the opening of the injection cannula.

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

The distance between the electrodes should preferably be less than 1 cm, as a result of which, as mentioned, losses due to body resistance are largely ruled out, so that the stimulators which are otherwise complex and expensive in terms of circuitry are not required. Rather, a simple electrical component is required which, in addition to a battery, essentially comprises only one current limiter. Because of the simple and therefore inexpensive design of the stimulation device, it can be thrown away after a single use.

Further details, advantages and features of the invention result not only from the claims, the features to be extracted from them - by themselves and / or in combination - but also from the following description of a preferred exemplary embodiment which can be seen from the drawing.

Show it:

1 is a schematic diagram of a catheter device,

2 shows a first embodiment of a cannula with a conductor applied on the outside,

Fig. 3 shows a second embodiment of a cannula with applied on the outside

Ladder,

4 shows an injection cannula arranged in an indwelling cannula, in particular intended for a catheter device according to FIGS. 1 and

5 shows a catheter, in particular for the catheter device according to FIG. 1.

1 shows, in principle, a catheter device 10 which shows an inner cannula 12 with a ground point 14 and a indwelling cannula 16 which surrounds the inner cannula 12.

The inner cannula 12 merges distally into an attachment piece 18 with a handle, not shown. The attachment 18 can be connected via a Luer lock connection to an attachment piece 22 from which the indwelling cannula 16 extends. At the rear end of the cannula attachment 18, a closable attachment piece 24 is provided, for example in order to be able to connect a syringe to the cannula 14

The metal cannula 12 is connected via an electrical cable 22 to an electrical component (not shown), which can essentially comprise a battery and a current limiter. The cable 22 can be in an electrically conductive connection to a first electrode, as is shown in FIG 2 to 4 is description. The second electrode can in turn originate from the indwelling cannula 16 or from the cannula 12 itself, a defined distance between the first and second electrodes being specifiable

2 and 3, purely by way of example, two cannulas 48, 50 made of conductive material such as steel are shown, which have a ground point (FIG. 2) or a pencil point (FIG. 3). The respective cannula 48, 50 is electrically detached from the outside thereof Insulating material coated like polyestei, the coating 60, 62 being 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. For the cannula 48 with a ground point, the free electrode 56 act as a cathode and in the case of the cannula 50 with a pencil point as an anode, that is to say on the respective coating 60 or 62 of the cannula 48 or 50 there is in the longitudinal direction of the respective cannula 48, 50 an electrically conductive strip such as conductor track 64, 66 eg applied by vapor deposition, the conductor track 64, 66 ending, for example, at a distance of approximately 0.8 cm from the tip of the cannula 48, 50, ie 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 an anode for the cannula 48 and a cathode for the cannula 50

As further illustrated in FIGS. 2 and 3, the conductor tracks 64, 66 run on the outer sides facing away from the openings 72, 74 of the cannulas 48, 52. FIG. 4 shows a section of a catheter device, the basic structure of which may correspond to that of FIG. 1. However, one with a pencil point is used as the cannula 12.

The cannula 10 can be made of metal and is electrically insulated on the outside by, for example, a 50 μm thick layer except for an area 34 located in the area of the tip 30 and forming a first electrode. The coating itself can be produced by powder coating.

In the exemplary embodiment, the second electrode is formed by an indwelling cannula 42 which surrounds the cannula 12 on the outside. The indwelling cannula 42 is preferably made of plastic and has, in its area remote from the lateral opening 28 of the cannula 12, an area 44 which forms the second electrode and which can be an anode. The dimensions of the cannula 12 or the extent of the indwelling cannula 42 along the outer surface of the cannula 12 and the location of the first electrode 34 are chosen such that the distance between the electrodes 34, 44 is smaller than the distance between the second electrode 44 and the is lateral opening or the eye 28, provided the cannula 10 should not 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 means of a wire 46 which is let into or injected into the indwelling cannula 42. Alternatively, there is the possibility of applying an electrical conductor to the outer surface of the indwelling cannula 42, such as vapor deposition, and then covering it with electrically insulating material down to the tip region which forms the second electrode 44. Independent of the exemplary embodiment in FIG. 4, there would of course also be the possibility of arranging the second electrode on the outer surface of the cannula 10 in accordance with the exemplary embodiment in FIG. 3.

After removal of the cannula 12, the indwelling cannula 16 remains in the body of a patient as an insertion aid for a catheter 76. A corresponding catheter 76 can be seen from the basic structure of FIG. 5.

In order to be able to continuously determine the area in which to inject even with continuous paramedular anesthesia, the catheter 76 to be inserted into the indwelling cannula 16 can be designed as a unipolar or bipolar stimulation catheter. A unipolar stiumulation catheter is present when the catheter 76 has a first electrically conductive electrode and the other electrode originates, for example, from the indwelling cannula 16 in the manner described above or is constructed in a manner known in the art.

In the exemplary embodiment, the catheter 76 is basically shown as a unipolar stium catheter. The catheter 76 is made of electrically insulating material and has a closed tip 78 and at a distance from it in a known manner at least one opening 80, even if more than one opening 80 are shown in the exemplary embodiment. The first electrically conductive electrode 82 is arranged on the closed tip 78. In the exemplary embodiment, a lenticular element made of electrically conductive material is arranged on the tip 78 for this purpose. This can be done, for example, by partially overmolding. An electrical conductor such as wire 84, which is guided within the catheter 76, then emanates from the electrode 82 and is led outward from the catheter device to the electrical circuit, via which the voltage required to stiumulate the paramedular area to be checked is applied. Alternatively, there would be the possibility of applying a second electrically conductive electrode to the outer surface of the catheter 76. This can be done, for example, by vapor deposition or other suitable measures, the electrically conductive connection from the second electrically conductive electrode to the electrical connection being covered in turn by electrically insulating material It would also be possible to lay an electrical conductor inside the catheter wall, which emerges from the wall at a desired location in order to form the second electrode

To become the guided through the catheter 76 the wire 84 may be bent at the distal end to the catheter and subsequently by a detachable part of a stimulator adapted This has the advantage that stimulated simultaneously and can be ied in _j as the outwardly guided wire does not affect the required tightness between catheter and syringe

Claims

Expectations

Stimulation device

Stimulation device, in particular intended for the stimulation of vascular nerve sheaths or in the paramedular area, comprising a voltage source and first and second electrodes (56, 58, 64, 66), of which a first electrode, which can be brought into a conductive connection via a body is in particular a tip-side section of an injection device to be inserted in the area of the body to be stimulated, such as a cannula (48, 50) with an opening (72, 74) for injecting pharmaceuticals such as anesthetics and the second electrode being spaced apart therefrom, characterized in that the injection device in the form of a cannula (48, 50) made 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 on the outside at a distance from the first electrode conductive connection (64, 66) arranged on the cannula and forming the second electrode ends t.

Stimulation device according to Claim 1, characterized in that the conductive connection, such as the conductor track (64, 66), is evaporated. 3. Stimulation device according to claim 1 or 2, characterized in that the conductive connection (64, 66) is covered up to the second electrode-forming region of electrically insulating material.

4. Stimulation device, in particular intended for the stimulation of vascular nerve sheaths or in the paramedular area, comprising a voltage source and first and second electrodes (56, 58, 64, 66), one of which can be brought into conductive connection via a body The first electrode is a section on the tip side, in particular, of an injection device to be inserted in the region of the body to be stimulated, such as a cannula (48, 50) with an opening (72, 74) for injecting pharmaceuticals such as anesthetics, and the second electrode is spaced apart from it, characterized in that the Injection device is an inner cannula (12, 48, 50) or a catheter (78) which is surrounded by an outer or indwelling cannula (16, 42), the second electrode (44, 68, 70) by the outer cannula or the inner cannula or the catheter runs out.

5. Stimulation device according to claim 4, characterized in that the catheter (76) has at least one lateral opening (80) and its tip (78) is closed, which is designed as a first electrode (82) or in which the first electrode is embedded.

6. Stimulation device according to at least one of the preceding claims, characterized in that the first electrode (82) of the catheter (76) preferably via a given if necessary, conductors (84), such as wire, running within the catheter or its wall are connected to the voltage source.

7. Stimulation device according to at least one of the preceding claims, characterized in that the second electrode is provided on the outside on the catheter (76).

8. Stimulation device according to at least one of the preceding claims, characterized in that the preferably made of plastic catheter (76) is provided on the outside with an electrical conductor which ends at a distance from the first electrode (82), the electrical conductor in turn except for one the region forming the second electrode is covered by electrically insulating material.

9. Stimulation device according to at least one of the preceding claims, characterized in that the catheter (76) consists of metal and is electrically insulated on the outside by a coating except for a region forming the first electrode (82) and that at a distance from it The first electrode ends with a conductive connection arranged on the outside on the catheter, which forms the second electrode.

10. Stimulation device according to at least one of the preceding claims, characterized in that the conductive connection is vapor-deposited as a conductor track.

11. Stimulation device according to at least one of the preceding claims, characterized in that the conductive connection is covered up to the second electrode-forming region of electrically insulating material. 12. Stimulation device according to at least one of the preceding claims, characterized in that the outer cannula (42) or indwelling cannula consists of plastic, in which an electrically conductive connection such as embedded or injected wire (46) to form a second electrode (44) Section runs.

13. Stimulation device according to at least one of the preceding claims, characterized in that there is a distance d with preferably d <learn between the first electrode (34) and the second electrode (40).