Set for nerve stimulation

Abstract

To provide a set for nerve stimulation that can apply direct stimulation.SOLUTION: The application relates to a set 10 for nerve stimulation with a device 100 for nerve stimulation with a distal end 100a, wherein the device comprises an electrically conductive simulation element and a duct for supply of fluid, and with an indwelling cannula 200 with an indwelling cannula conduit 240 with a distal end 240a and a proximal end, wherein the device comprises a first connector member 180 and the indwelling cannula comprises a second connector member 280 complementary to the first connector member, wherein, by connecting the first connector member and the second connector member, the device is fixable in an axial position in which the distal end of the device projects beyond the distal end of the indwelling cannula, wherein, in a connected state of the first connector member and the second connector member, the first connector member and the second connector member are connected with one another such that a circumferential first seal is formed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a set for neurostimulation. [Background technology]

[0002] It is known to transmit current pulses, for example low-frequency alternating current at low voltage, by means of electrodes placed on the skin, thus stimulating nerves transcutaneously, for pain relief or muscle relaxation, but in this case the skin presents a relatively large transition resistance, and moreover the stimulation usually occurs over a large area.

[0003] Furthermore, with regard to positioning the tip of the cannula, in particular to estimate whether the tip of the cannula is in contact with a nerve, it is known to design a rigid cannula that is inserted into the skin, and in particular also threaded into an indwelling cannula, so that it can be stimulated using a power connection. Summary of the Invention [Problem to be solved by the invention]

[0004] It is therefore an object of the present invention to provide improved possibilities for nerve stimulation which are particularly versatile and preferably allow for more direct stimulation. [Means for solving the problem]

[0005] The problem according to the invention is solved by a set for nerve stimulation having the features of claim 1. Advantageous embodiments and developments of the invention are set forth in the dependent claims.

[0006] A set for nerve stimulation according to the present invention comprises a device for nerve stimulation having a distal end, the device having a conductive stimulation element and a passage for supplying a fluid, and further comprises an indwelling cannula having an indwelling cannula tube including a distal end and a proximal end, the device having a first connector member, the indwelling cannula having a second connector member complementary to the first connector member, by connecting the first connector member and the second connector member, the device can be fixed in an axial position in which the distal end of the device protrudes beyond the distal end of the indwelling cannula, and in the connected state of the first connector member and the second connector member, the first connector member and the second connector member are connected to each other such that a first circumferential seal is formed.

[0007] The set according to the invention is suitable for both neurostimulation and for the delivery of fluids, such as liquids, for example anesthetic drugs. The device can be placed in the body for a long period of time via an indwelling cannula, allowing a wide range of applications. The indwelling cannula tube can be made of plastic, preferably polyamide, and can preferably be of an electrically insulating design. In particular, the indwelling cannula tube has a higher bending stiffness than the part of the device for neurostimulation that is introduced into the indwelling cannula, which makes it easier to feed the device through the indwelling cannula tube. On the other hand, a flexible form of the indwelling cannula tube is desirable in order to cause as little unpleasant effects as possible to the patient, even if the indwelling cannula is left in the body for a long period of time.

[0008] The first circumferential seal seals the space between the device for neurostimulation and the retention cannula and allows for the introduction of fluids into this space, which has the advantage that the device for neurostimulation placed in the retention cannula can be better viewed by ultrasound over the entire length of the retention cannula.

[0009] Preferably, the first seal is formed by abutting a first contact surface of the first connector member against a second contact surface of the second connector member, thereby avoiding additional components such as, for example, a sealing ring.

[0010] According to an advantageous development, the first connector member has a distal face on which a first axially projecting circumferential projection is arranged, and the second connector member has a proximal face on which a second axially projecting circumferential projection is arranged, the first contact surface being arranged on the outside of the first projection and the second contact surface being arranged on the inside of the second projection, or alternatively the first contact surface being arranged on the inside of the first projection and the second contact surface being arranged on the outside of the second projection. In this way, a circumferential abutment surface can be formed between the first and second contact surfaces over the axial extension, which abutment surface can ensure the formation of the first seal.

[0011] Preferably, the first contact surface has a circumferential protrusion protruding in the direction of the second contact surface and / or the second contact surface has a circumferential protrusion protruding in the direction of the first contact surface, which protrusion can in particular cause the first protrusion and the second protrusion to abut against one another under bias, thereby improving the sealing effect.

[0012] According to a preferred embodiment of the invention, it is provided that the second connector member sealingly surrounds the indwelling cannula tube at the distal end and expands in the direction of the proximal end, so that adjacent to the proximal end of the second connector member an annular gap is formed between the second connector member and the introduced device, and that the first connector member has an annular groove opening in the direction of the distal end, into which the proximal end of the second connector member penetrates in the connected state of the first and second connector members. Such an assembly can enable a simple connection. Furthermore, this configuration can improve the sealing effect.

[0013] Preferably, the first protrusion is disposed on the bottom surface of the annular groove, whereby the seal formed between the first connector member and the second connector member can be positioned to be protected from external influences.

[0014] Advantageously, the passageway of the device, in particular the tube of the device, has a side opening which, in particular in the connected state of the first connector member and the second connector member, opens into the annular gap, which makes it possible to simply fill the annular gap between the second connector member and the adjacent indwelling cannula tube and the introduced device with a fluid.

[0015] A particularly preferred embodiment of the invention provides that the connection of the first connector part with the second connector part is effected by a bayonet lock, the locking of which is preferably perceptible tactilely and / or acoustically. The bayonet lock can be opened and closed quickly and simply mechanically by plugging the two connector parts into one another and rotating them in opposite directions. In the locked position, the pin of the bayonet lock engages in the locking receptacle. The locking resistance can preferably be selected to be large enough to be perceptible tactilely and / or acoustically by the user, for example through a clicking sound, thereby increasing the reliability of operation.

[0016] Preferably, the stimulation element is designed as an electrically conductive stimulation wire having a diameter, a distal end and a proximal end, the passage is designed as an electrically insulating tube having an inner diameter, an outer diameter, a distal end and a proximal end, the stimulation wire is arranged in the tube, the inner diameter of the tube is larger than the diameter of the stimulation wire, whereby a gap for the fluid supply is formed in the tube, and a stimulation electrode is arranged conductively at the distal end of the stimulation wire, which protrudes beyond the distal end of the tube. The fact that the stimulation wire is arranged in the lumen of the tube allows for a particularly compact construction.

[0017] Furthermore, the flexibility of the tube provides an elongated, flexible device that can be introduced into the body either by a cannula or an indwelling cannula, but also through natural body orifices, such as the nose, bladder, vagina, etc., without the need to cut the skin, thereby stimulating nerves that are difficult or impossible to access with stimulation electrodes attached to the skin outside the body.

[0018] Preferably, the proximal end of the stimulation wire protrudes beyond the proximal end of the tube and is bent back at the proximal end of the tube to guide it outside the tube, a conductive stimulation cable is conductively connected to the proximal end of the stimulation wire, and an infusion tube is partially sealingly fitted over the proximal end of the tube. The bent stimulation wire at the proximal end of the tube allows the stimulation cable to be easily coupled outside the tube without having to pass the stimulation wire through the wall of the tube, thereby avoiding the possibility of leakage.

[0019] According to an advantageous development of the invention, the stimulation electrode has a rounded outer surface, for example formed in a hemispherical, spherical, elliptical, mushroom-shaped, pear-shaped or egg-shaped form. The rounded form makes it possible to avoid injuries to the body of the person to be treated. Furthermore, such a form of the stimulation electrode allows for easy delivery of the device, in particular through body openings.

[0020] Preferably, the stimulation electrode has an outer diameter in each cross section that is equal to or smaller than the outer diameter of the tube, in other words, the outer dimensions of the stimulation electrode are not larger than the outer dimensions of the tube, so that the stimulation electrode does not protrude laterally, which allows for easy feeding of the device through the indwelling cannula.

[0021] In principle, it is conceivable that the fluid can exit at the distal end of the tube between the stimulation electrode and the tube wall. Advantageously, the stimulation electrode is form-fittingly arranged at the distal end of the tube by means of an attachment, the tube having at least one infusion opening in its wall opening into the gap between the stimulation wire and the tube and / or the stimulation electrode having an axial through opening. The form-fitting arrangement allows the distal end of the stimulation wire to be stabilized in the tube. Furthermore, the form-fitting arrangement can allow the distal end of the tube to be closed in order to prevent particles from entering the distal end of the tube or from clogging the distal end of the tube. In this embodiment, the fluid can exit laterally through at least one infusion opening arranged in the wall of the tube and / or through the axial through opening of the stimulation electrode.

[0022] Preferably, the proximal end of the tube is arranged in the housing together with the connection points to the stimulation cable and the connection points to the infusion tube, the stimulation cable and the infusion tube exiting the housing proximally, in particular parallel to the longitudinal axis of the tube, and the first connector member is arranged in the housing, in particular integrally connected thereto. In that case, the proximal end of the tube including the connection points can be placed in the housing and optionally surrounded by the housing by pouring in adhesive or injection molding. In this way, the connection points can be protected and arranged.

[0023] The diameter of the stimulation wire is preferably less than 0.3 mm, preferably less than 0.2 mm, particularly preferably less than 0.1 mm. In this way, a thin and flexible stimulation wire can be provided which can allow easy delivery into the body.

[0024] Preferably, the stimulation wire is made of stainless steel, whereby the necessary stability of the stimulation wire can be achieved, especially when the length exceeds 10 cm. According to a particularly preferred embodiment of the invention, the outer diameter of the tube is less than 1.0 mm, preferably less than 0.9 mm, thereby allowing for sizing of the device for nerve stimulation which allows for easy introduction into the body.

[0025] Preferably, the inner diameter of the tube is in the range of 0.4 mm to 0.7 mm, preferably in the range of 0.5 mm to 0.6 mm, such dimensioning allows a sufficient gap between the inner wall of the tube and the stimulation wire to allow fluid to be conducted through the tube from the proximal end to the distal end.

[0026] According to a preferred development of the invention, the length of the tube is more than 5 cm, preferably more than 8 cm, particularly preferably more than 10 cm, thereby providing a sufficient length to allow the device for nerve stimulation to be inserted sufficiently deep inside the body.

[0027] A preferred embodiment of the invention provides for the tube to be made of plastic, for example polyamide, as such a material may allow for sufficient tightness, high flexibility and good biocompatibility.

[0028] A preferred development of the invention provides that the set further comprises a rigid cannula having a cannula tube with a distal end and a proximal end for insertion into the body, onto which the retention cannula can be fitted before insertion, and which has at its proximal end a third connector member complementary to the second connector member, by connecting the third connector member and the second connector member the cannula can be fixed in an axial position in which the distal end of the cannula tube projects beyond the distal end of the retention cannula, the third connector member and the second connector member being connected to each other in such a way that a second circumferential seal is formed. The rigid cannula allows the introduction of the retention cannula through the skin into the body in order to be able to stimulate nerves that are not accessible by stimulation through the skin.

[0029] Advantageously, the second seal is formed by abutting the third contact surface of the third connector member against the second contact surface of the second connector member, thereby making it possible to avoid additional components such as, for example, a sealing ring.

[0030] According to a preferred embodiment of the invention, it is provided that the third connector member has a distal face on which a circumferential third axial projection is arranged, the third contact surface being arranged on the outside of the third projection and the second contact surface being arranged on the inside of the second projection, or alternatively, the third contact surface being arranged on the inside of the third projection and the second contact surface being arranged on the outside of the second projection. In this way, a circumferential abutment surface can be formed between the third contact surface and the second contact surface over the axial extension, which abutment surface can ensure the formation of the second seal.

[0031] Preferably, the third contact surface has a circumferential protrusion protruding in the direction of the second contact surface and / or the second contact surface has a circumferential protrusion protruding in the direction of the third contact surface, which protrusion can in particular cause the third protrusion and the second protrusion to abut against one another under bias, thereby improving the sealing effect.

[0032] Advantageously, the third connector member has an annular groove which is open towards the distal end and into which the proximal end of the second connector member enters in the connected state of the third connector member and the second connector member. Such an assembly can enable a simple connection. Furthermore, this configuration can improve the sealing effect.

[0033] Preferably, the third protrusion is disposed on the bottom surface of the annular groove, which allows the seal formed between the third connector member and the second connector member to be protected from external influences.

[0034] Preferably, the cannula tube has a side opening that opens into the annular gap, particularly in the connected state of the third connector member and the second connector member, which allows the annular gap between the second connector member and the adjacent indwelling cannula tube and the introduced cannula to be simply filled with a fluid, thereby improving the ultrasound visibility of the cannula, particularly when the cannula is inserted into the body.

[0035] In an advantageous development, the connection of the third connector part with the second connector part is effected in a bayonet locking manner, the locking of which is preferably perceptible tactilely and / or acoustically. The bayonet lock can be opened and closed quickly and simply mechanically by plugging the two connector parts into one another and rotating them in opposite directions. In the locked position, the pin of the bayonet lock engages in the locking receptacle. The locking resistance can preferably be selected so that it is tactilely and / or acoustically perceptible to the user, for example through a clicking sound, thereby increasing the reliability of operation.

[0036] Particularly preferably, the third connector member is formed substantially identically to the first connector member. Advantageously, the cannula tube is made of a conductive material, the conductive stimulation cable is conductively connected outside the cannula tube, and the infusion tube is partially sealingly fitted onto the proximal end of the cannula tube, so that the cannula is suitable for both neurostimulation and for the delivery of fluids, e.g., liquids such as anesthetic agents, and can be constructed compactly.

[0037] Preferably, the proximal end of the cannula tube is arranged in the housing together with the connection points to the stimulation cable and the connection points to the infusion tube, the stimulation cable and the infusion tube exiting the housing proximally, in particular parallel to the longitudinal axis of the cannula tube, and the third connector member is arranged in the housing, in particular integrally connected thereto. In that case, the proximal end of the tube including the connection points can be placed in the housing and optionally surrounded by the housing by pouring in glue or injection molding. In this way, the connection points can be protected and positioned.

[0038] Exemplary embodiments of the invention are described with reference to the following figures: [Brief description of the drawings]

[0039] [Figure 1] Figure 1a is a side view of a set for neurostimulation comprising a device for neurostimulation having a first connector member and an indwelling cannula having a second connector member, the device being placed in the indwelling cannula, and Figure 1b is a diagram showing the device for neurostimulation according to Figure 1a without the indwelling cannula. [Diagram 2] FIG. 1b is a longitudinal section of the device according to FIG. [Diagram 3] FIG. 3 is an enlarged detail of FIG. 2 showing the electrical connections of the stimulation wires of the device for nerve stimulation. [Figure 4] FIG. 3 is an enlarged detail view of the distal end of the device of FIG. 2. [Diagram 5] FIG. 4 is an enlarged detail of FIG. 3 showing the bent portion of the stimulation wire. [Figure 6] FIG. 2 is a detailed longitudinal section of the device placed in the indwelling cannula according to FIG. 1. [Figure 7] FIG. 7 is an enlarged detail view of FIG. 6 with the first connector member and the second connector member connected. [Figure 8] 8 is a view equivalent to FIG. 7, but with the first and second connector members removed; FIG. [Figure 9] FIG. 7 is another enlarged detail of FIG. 6 showing the openings of the tubes of the device for nerve stimulation. [Figure 10] 2 is a longitudinal cross-sectional view of the indwelling cannula of FIG. 1 with a cannula having a third connector member disposed therein. [Figure 11] FIG. 11 is an enlarged detail view of FIG. 10 with the third connector member and the second connector member connected. [Figure 12] 12 is a view equivalent to FIG. 11 with the third connector member and the second connector member removed; FIG. [Figure 13] FIG. 11 is an enlarged detail of FIG. 10 showing the electrical connections of the cannula. [Figure 14] 11 is another enlarged detail of FIG. 10 showing the side opening of the cannula tube of the cannula. [Figure 15] 11 is a top view of the device for nerve stimulation according to FIG. 1b and the distal end of the cannula according to FIG. 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] 1 to 15 show different views of an exemplary embodiment of a set 10 for neurostimulation. For clarity, not all reference numbers are shown in all figures. The set 10 for neurostimulation comprises at least one device 100 for neurostimulation and an indwelling cannula 200, which are described in more detail with reference to Figures 1 to 9, and may optionally comprise a cannula 300, which are described in more detail with reference to Figures 10 to 15.

[0041] The device 100 comprises an electrically conductive stimulation element, in particular designed as an electrically conductive stimulation wire 120 having a diameter AD, a distal end 120a and a proximal end 120b. The stimulation wire 120 can be a flexible and bendable wire. The stimulation wire 120 is made, for example, of stainless steel. The diameter AD of the stimulation wire 20 is preferably less than 0.3 mm, preferably less than 0.2 mm, particularly preferably less than 0.1 mm, for example about 0.07 mm.

[0042] Furthermore, the device 100 comprises a passage for supplying a fluid, designed as an electrically insulating tube 140 having an inner diameter IS, an outer diameter AS, a distal end 140a and a proximal end 140b. The tube 140 is particularly flexible, dicht and biocompatible. The tube 140 can be made, for example, of plastic, preferably polyamide. The outer diameter AS of the tube 140 is preferably less than 1.0 mm, particularly preferably less than 0.9 mm, for example 0.87 mm. The inner diameter IS of the tube 140 is greater than the diameter AD of the stimulation wire 120 and can be in the range of 0.4 mm to 0.7 mm, preferably in the range of 0.5 mm to 0.6 mm, for example 0.54 mm. The length L of the tube 140 is more than 5 cm, preferably more than 8 cm, for example 8.35 cm, particularly preferably more than 10 cm, for example 11.35 or 16.35 cm. The tube 140 may have markings 144 starting at the distal end 140a (see FIG. 1b), which may be particularly equally spaced to provide the user with information regarding the length of the distal end 140a of the tube 140 that has been introduced into the body.

[0043] The stimulation wire 120 is in particular disposed within the tube 140 and in particular threaded through the lumen of the tube 140. In that case, the inner diameter IS of the tube 140 is larger than the diameter AD of the stimulation wire 120, thereby forming a gap 146 within the tube 140 through which liquid can be conducted from the proximal end 140b of the tube 140 to the distal end 140a of the tube 140, as will be explained in more detail below. The gap 146 can be formed in the form of an annular gap between the stimulation wire 120 and the inner wall of the tube 140, if the stimulation wire 120 is disposed substantially in the center of the lumen. Alternatively, the stimulation wire 120 can abut against the inner wall of the tube 140, thereby forming the gap 146 in a crescent shape.

[0044] A stimulating electrode 130 is conductively disposed at the distal end 120a of the stimulating wire 120, which protrudes beyond the distal end 140a of the tube 140. The stimulating electrode 130 has a rounded outer surface 132 and can be formed, for example, in a hemispherical, spherical, elliptical, mushroom, pear or egg shape, or otherwise ball-like shape. Due to its convex morphology, the stimulating electrode 130 has a maximum outer diameter AE in at least one cross section. However, this outer diameter AE of the stimulating electrode 130 is at most as large as the outer diameter AS of the tube 140 (see in particular FIG. 4 ).

[0045] The conductive connection between the stimulation wire 120 and the stimulation electrode 130 can be formed, for example, by the distal end 120a of the stimulation wire 120 being fixed by welding to an attachment portion 134 disposed on the stimulation electrode 130, or by being clamped between the attachment portion 134 and a tube 140 (see FIG. 4).

[0046] The stimulation electrode 130 can be form-fittingly arranged on the distal end 140a of the tube 140 by means of the attachment 134, more precisely on the section 148 extending from the distal end 140a of the tube 140. The attachment 134 can have one or more notches on its outer side, which improve the clamping fixation of the attachment 134 on the section 148 of the tube 140. Thereby, the stimulation electrode 130, in particular the attachment 134, can occlude the distal end 140a of the tube 140. In order to allow the fluid arranged in the gap 146 to flow out at the distal end 100a of the device 100, the tube 140 can have at least one injection opening (not shown) in its wall, which opens into the gap 146 between the stimulation wire 120 and the tube 140, and / or the stimulation electrode 130 can have an axial through opening 136.

[0047] The proximal end 120b of the stimulation wire 120 protrudes beyond the proximal end 140b of the tube 140 and is folded back at the proximal end 140b of the tube 140, particularly at the bend 122, particularly by bending about 180°, and guided to the outside of the tube 140 (see Figs. 3 and 5). The conductive stimulation cable 150, particularly the conductive core 152 of the stimulation cable 150, is conductively connected at the proximal end 120b of the stimulation wire 120, and the stimulation wire rests on the outside of the tube 140, particularly by the folded back portion 123 adjacent to the bend 122. Thus, the conductive contact of the stimulation wire 120 can be made outside the lumen of the tube 140, which is often filled with liquid during use, and without penetrating the wall of the tube 140. The stimulation cable 150, and in particular the core 152 of the stimulation cable 150, can be conductively connected to the stimulation wire 120, and in particular the folded portion 123 (see in particular FIG. 3), for example by a crimp sleeve 125. As can be seen in FIG. 2, an electrical plug connection 154 can be located at the other end of the stimulation cable 150 for connecting a control device to a pulse generator.

[0048] The injection tube 160 can be partially sealed over the proximal end 140b of the tube 140, and in that case in particular also partially over the folded-back portion 123 of the stimulation wire 120 that is outside the tube 140. This can be achieved, for example, by the inner diameter of the injection tube 160 approximately corresponding to the outer diameter AS of the tube 140. As can be seen in FIG. 2, a syringe connection 164 can be arranged at the other end of the injection tube 160, via which a fluid, for example an anaesthetic agent, can be injected into the injection tube 160, for example by means of a syringe, the fluid flowing through the injection tube 160 to the proximal end 140b of the tube 140 and flowing out at the distal end 140a of the tube 140, in particular through the axial through opening 136 of the stimulation electrode 130.

[0049] The proximal end 140b of the tube 140, having the connection points to the stimulation cable 150 and the connection points to the infusion tube 160, can be arranged in the housing 170, with the stimulation cable 150 and the infusion tube 160 exiting the housing 170 proximally, in particular parallel to the longitudinal axis of the tube 140. In that case, the proximal end 140b of the tube 140, including the connection points, can be placed in the housing 170 and can be additionally surrounded by the housing 170 by pouring in adhesive or injection molding. In this way, the connection points can be protected and arranged. The housing 170 can be arranged with one or more grip recesses 172 for the placement of the user's fingers to increase grip security.

[0050] The retention cannula 200 includes a retention cannula tube 240 having an inner diameter IV, an outer diameter AV, a distal end 240a, and a proximal end 240b. The retention cannula tube 240 may be made of plastic, preferably polyamide, and preferably of an electrically insulating material. Of particular advantage, the retention cannula tube 240 may incorporate an X-ray contrast strip. The inner diameter IV is greater than the outer diameter AS of the tube 140 of the device 100, so that the tube 140 of the device 100 can be introduced into the retention cannula 200. In particular, the retention cannula tube 240 has a higher bending stiffness than the tube 140.

[0051] For the relative positional fixation, the device 100 comprises a first connector member 180, while the retention cannula has a second connector member 280 complementary to the first connector member 180, and by connecting the first connector member 180 and the second connector member 280, the device 100 can be fixed in an axial position in which the distal end 100a of the device 100 protrudes beyond the distal end 240a of the retention cannula 240. The first connector member 180 can be arranged near the proximal end 140b of the tube 140 of the device 100, while the second connector member 280 can be arranged near the proximal end 240b of the retention cannula tube 240 of the retention cannula 100. In particular, the first connector member 180 can be arranged in the housing 170 of the device 100, and preferably can be integrally connected to the housing 170 of the device 100.

[0052] In a connected state of the first connector member 180 and the second connector member 280, the first connector member 180 and the second connector member 280 are connected to each other such that a circumferential first seal 400 is formed (see FIG. 7). In this case, the first seal 400 can be formed, for example, by abutting the first contact surface 181 of the first connector member 180 against the second contact surface 281 of the second connector member 280.

[0053] The first connector member 180 can have a distal face 182 on which an axially projecting circumferential first protrusion 185 is arranged. The second connector member 280 can have a proximal face 282 on which an axially projecting circumferential second protrusion 285 is arranged. As shown in figures 7 and 8, the first contact surface 181 is arranged on the outside of the first protrusion 185 and the second contact surface 281 is arranged on the inside of the second protrusion 285. In an alternative embodiment not shown, it is also conceivable that the first contact surface 181 is arranged on the inside of the first protrusion 185 and the second contact surface 281 is arranged on the outside of the second protrusion 285. In both embodiments, the two protrusions 185, 285 are arranged relative to each other in particular such that their contact surfaces 181, 182 pass each other when the two connector members 180, 280 are connected.

[0054] As can be seen in particular in Fig. 8, the second contact surface 281 can have a circumferential protrusion 283 projecting in the direction of the first contact surface 181. Alternatively or additionally, the first contact surface 181 can have a circumferential protrusion (not shown) projecting in the direction of the second contact surface 281.

[0055] The second connector member 280 may sealingly surround the retention cannula tube 240 at its distal end 280a, and in particular the proximal end 240b of the retention cannula tube 240, and expand in the direction of the proximal end 280b, such that when the device 100 is introduced into the retention cannula 200, an annular gap 410 is formed between the second connector member 280 and the introduced device 100 adjacent the proximal end 280b of the second connector member 280 (see in particular Figures 6 and 9). The annular gap 410 tapers in particular in the distal direction (see Figure 9).

[0056] The passageway of the device 100, particularly the tube 140 of the device 100, may have a side opening 149 that opens into the annular gap 410, particularly in the connected state of the first connector member 180 and the second connector member 280.

[0057] The first connector member 180 has an annular groove 187 that is open toward the distal end 180a of the first connector member 180, and in a connected state between the first connector member 180 and the second connector member 280, the proximal end 280b of the second connector member 280 fits into the annular groove (see particularly Figures 7 and 8). In this case, the first protrusion 185 can be disposed on the bottom surface 187a of the annular groove 187.

[0058] The connection of the first connector part 180 and the second connector part 280 can be effected by bayonet locking, in particular by inserting the proximal end 280b of the second connector part 280 into the annular groove 187 of the first connector part 180 and then rotating the two connector parts 180, 280 in opposite directions. The pin 288 of the second connector part 280 can then be guided into the groove 188 of the first connector part 180. The bayonet lock at the end of the groove 188, in particular the locking of the pin 288 into a corresponding recess, is preferably perceptible tactilely and / or acoustically.

[0059] The set 10 may further comprise a rigid cannula 300 having a distal end 340a and a proximal end 340b, and a cannula tube 340 having an outer diameter AK and an inner diameter IK, the distal end 340a being particularly tipped for insertion into the body (see in particular FIG. 15). The cannula tube 340 may be made of a conductive material, for example stainless steel, and has an insulating coating on the outside, except for the distal end 340a and the connection point to the stimulation cable 360. The outer diameter AK of the cannula tube 340 is smaller than the inner diameter IV of the indwelling cannula tube 240, so that the indwelling cannula tube 240 can be fitted over the cannula tube 340 prior to insertion. The outside of the cannula tube 340 may be embossed to enhance ultrasound visibility.

[0060] The outer diameter AK of the cannula tube 340 is preferably less than 1.0 mm, and may be, for example, 0.95 mm. The inner diameter IK of the cannula tube 340 may be in the range of 0.4 mm to 0.7 mm, and may be, for example, 0.65 mm.

[0061] The conductive contact of the cannula tube 340 can be made directly on the outer wall of the cannula tube 340. To that end, the stimulation cable 350, and in particular the core 352 of the stimulation cable 350, can be conductively connected to the cannula tube 340, for example by means of a crimp sleeve 325 (see in particular FIG. 13). As can be seen in particular in FIG. 10, an electrical plug connection 354 can be arranged at the other end of the stimulation cable 350 for connecting a control device to a pulse generator.

[0062] The injection tube 360 ​​can be partially sealed over the proximal end 340b of the cannula tube 340 (see FIG. 13). This can be achieved, for example, by having an inner diameter of the injection tube 360 ​​approximately correspond to the outer diameter AK of the cannula tube 340. As can be seen in FIG. 10, a syringe connection 364 can be arranged at the other end of the injection tube 360, via which a fluid, for example an anesthetic agent, can be injected into the injection tube 360, for example with a syringe, the fluid flowing through the injection tube 360 ​​into the proximal end 340b of the cannula tube 340 and flowing out at the distal end 340a of the cannula tube 340, in particular through the sharpened tip.

[0063] The proximal end 340b of the cannula tube 340, which has a connection point to the stimulation cable 350 and a connection point to the infusion tube 360, can be arranged in the housing 370, and the stimulation cable 350 and the infusion tube 360 ​​exit the housing 370 proximally, in particular parallel to the longitudinal axis of the cannula tube 340 (see FIG. 10). In that case, the proximal end 340b of the cannula tube 340, including the connection points, can be placed in the housing 370 and can be additionally surrounded by the housing 370 by pouring in adhesive or injection molding. In this way, the connection points can be protected and arranged. The housing 370 can be arranged with one or more grip recesses for the user's fingers to place in order to increase grip security.

[0064] The cannula 300 includes a third connector member 380 that is designed to be complementary to the second connector member 280 of the indwelling cannula and allows for relative positioning of the cannula 300 and the indwelling cannula 200. By connecting the third connector member 380 and the second connector member 280, the cannula 300 can be fixed in an axial position in which the distal end 340a of the cannula tube 340 protrudes beyond the distal end 240a of the indwelling cannula 240. The third connector member 380 can be disposed near the proximal end 340b of the cannula tube 340 of the cannula 300. In particular, the third connector member 380 can be disposed in, and preferably integrally connected to, the housing 370 of the cannula 300.

[0065] The third connector member 380 may substantially correspond in its functional characteristics to the first connector member 180, in particular to secure both the cannula 300 and / or the device for neurostimulation 100 within an indwelling cannula, as will be further described below.

[0066] In a connected state of the third connector member 380 and the second connector member 280, the third connector member 380 and the second connector member 280 are connected to each other such that a circumferential second seal 500 is formed (see FIG. 11 ). In this case, the second seal 500 can be formed, for example, by abutting the third contact surface 381 of the third connector member 380 against the second contact surface 281 of the second connector member 280.

[0067] The third connector member 380 may have a distal surface 382 on which an axially projecting circumferential third protrusion 385 is arranged. As shown in figures 11 and 12, the third contact surface 381 is arranged on the outside of the third protrusion 385 and the second contact surface 281 is arranged on the inside of the second protrusion 285. In an alternative embodiment not shown, it is also conceivable that the third contact surface 381 is arranged on the inside of the third protrusion 385 and the second contact surface 281 is arranged on the outside of the second protrusion 285. In both embodiments, the two protrusions 385, 285 are arranged relative to each other such that their contact surfaces 281, 382 pass each other when the two connector members 280, 380 are connected.

[0068] As can be seen in particular in Figure 12 and as already explained on the basis of Figure 8, the second contact surface 281 can have a circumferential protrusion 283 projecting in the direction of the third contact surface 381. Alternatively or additionally, the third contact surface 381 can have a circumferential protrusion (not shown) projecting in the direction of the second contact surface 281.

[0069] As already explained, the second connector member 280 may sealingly surround the indwelling cannula tube 240 at its distal end 280a, in particular the proximal end 240b of the indwelling cannula tube 240, and may expand in the direction of the proximal end 280b, such that, even when the cannula 300 is introduced into the indwelling cannula 200, an annular gap 510 is formed between the second connector member 280 and the introduced cannula 300 adjacent the proximal end 280b of the second connector member 280 (see in particular FIG. 10 ). The annular gap 510 may taper in particular in the distal direction and may extend in particular along the indwelling cannula tube 240 to its distal end 240a.

[0070] The cannula tube 340 may have a side opening 349 that opens into the annular gap 510, particularly in the connected state of the third connector member 380 and the second connector member 280 (see Figures 10 and 14).

[0071] The third connector member 380 has an annular groove 387 that is open toward the distal end 380a of the third connector member 380, and the proximal end 280b of the second connector member 280 fits into the annular groove when the third connector member 380 and the second connector member 280 are in a connected state (see particularly Figures 11 and 12). The third protrusion 385 can be disposed on a bottom surface 387a of the annular groove 387.

[0072] The connection of the third connector member 380 with the second connector member 280 can be effected by bayonet locking, in particular by inserting the proximal end 280b of the second connector member 280 into an annular groove 387 of the third connector member 380 and then rotating the two connector members 380, 280 in opposite directions. The pin 288 of the second connector member 280 can then be guided into the groove 388 of the third connector member 380. The bayonet lock at the end of the groove 188, in particular the locking of the pin 288 into a corresponding recess, is preferably perceptible tactilely and / or acoustically.

[0073] Set 10 can be used as follows: First, the indwelling cannula 200 can be pushed over the cannula tube 340 of the cannula 300, and the second connector member 280 can be connected to the third connector member 380. In that case, the sharp distal end 340a of the cannula tube 340 protrudes beyond the distal end 240a of the indwelling cannula tube 240. These two components can be inserted together into the body. In that case, a liquid can be injected into the cannula tube 340 via the injection tube 360 ​​and into the annular gap 510 between the cannula tube 340 and the inner wall of the indwelling cannula tube 240 via the side opening 349, which improves the ultrasonic visibility of the cannula tube 340 when it is introduced into the body, but cannot exit the body due to the second seal 500. Meanwhile, stimulation can be performed via the stimulation cable 350 by applying current pulses to the cannula tube 340 to obtain information about the positioning of the tip of the cannula tube 340 inside the body.

[0074] Once the cannula 300 is placed at the desired location, the connection between the third connector member 380 and the second connector member 280 is released and the cannula 300 can be withdrawn from the retention cannula 200 while the retention cannula 200 remains placed in the body. The tube 140 with the stimulation wire 120 of the device 100 for nerve stimulation can then be passed through the retention cannula 200 until the distal end of the device 100a, in particular the stimulation electrode 130, emerges from the distal end 240a of the retention cannula 240. In that case, both stimulation can be performed by applying corresponding current pulses via the stimulation cable 150, and injection of a liquid, for example an anesthetic, via the injection tube 160. The flexible retention cannula 200 then allows for long-term placement in the body and for the device 100 to be placed close to nerves that are usually difficult to access via the body surface. [Explanation of symbols]

[0075] 10 sets 100 devices 100a Distal end 120 Stimulation Wire 120a Distal end 120b proximal end 122 Bend 123 Folding part 125 Crimp Sleeve 130 stimulation electrode 132 Exterior 134 Mounting part 136 Axial through opening 140 Tubes 140a Distal end 140b proximal end 144 Marking 146 Gap 148 parts 149 Side opening 150 Stimulation Cable 152 Core Wire 154 Electrical plug connection 160 Injection tube 164 Syringe connection 170 Housing 172 Grip recess 180 first connector member 180a Distal end 181 First Contact Surface 182 distal surface 185 First protrusion 187 Circular Groove 187a Bottom 188 Groove 200 Indwelling Cannula 240 Indwelling Cannula Tube 240a Distal end 240b Proximal end 280 Second connector member 280a Distal end 280b Proximal end 281 Second Contact Surface 282 Proximal surface 283 Convex 285 Second protrusion 288 Pin 300 Cannula 325 Crimp Sleeve 340 Cannula 340a Distal end 340b Proximal end 349 Side opening 350 Stimulation Cable 352 Core Wire 354 Electrical plug connection 360 Injection Tube 364 Syringe connection 370 Housing 380 Third connector member 380a Distal end 381 Third Contact Surface 382 distal surface 385 Third protrusion 387 Circular Groove 387a Bottom 388 Groove 400 First Seal 410 Annular gap 500 Second Seal 510 Annular gap AD Stimulation wire diameter AS Tube Outer Diameter IS Tube Inner Diameter Outer diameter of AE stimulation electrode Outer diameter of AV indwelling cannula tube Inner diameter of IV cannula tubing AK Cannula Outer Diameter IK Cannula inner diameter L Length

Claims

1. A set (10) for nerve stimulation, A device (100) for nerve stimulation having a distal end (100a), the device (100) having an electrically conductive stimulation element and a passage for supplying a fluid; an indwelling cannula (200) having an indwelling cannula tube (240) including a distal end (240a) and a proximal end (240b); The device (100) has a first connector member (180); The indwelling cannula (200) has a second connector member (280) complementary to the first connector member (180); by connecting the first connector member (180) and the second connector member (280), the device (100) can be fixed in an axial position in which the distal end (100a) of the device (100) projects beyond the distal end (240a) of the retention cannula (200); In a connected state of the first connector member (180) and the second connector member (280), the first connector member (180) and the second connector member (280) are connected to each other such that a first circumferential seal (500) is formed. Set (10).

2. the first seal (500) is formed by abutting a first contact surface (181) of the first connector member (180) against the second contact surface (281) of the second connector member (280), The set according to claim 1.

3. the first connector member (180) having a distal surface (182) on which an axially extending circumferential first projection (185) is disposed; the second connector member (280) having a proximal surface (182) on which is disposed a second axially projecting circumferential projection (285); the first contact surface (181) is arranged on the outside of the first protrusion (185) and the second contact surface (281) is arranged on the inside of the second protrusion (285), or alternatively the first contact surface (181) is arranged on the inside of the first protrusion (185) and the second contact surface (182) is arranged on the outside of the second protrusion (285), The set according to claim 2.

4. characterised in that the first contact surface (181) has a circumferential convexity projecting in the direction of the second contact surface (281) and / or the second contact surface (281) has a circumferential convexity projecting in the direction of the first contact surface (181), A set according to claim 2 or 3.

5. the second connector member (280) sealingly surrounds the indwelling cannula tube (240) at its distal end (280a) and expands toward its proximal end (280b) such that adjacent the proximal end (280b) of the second connector member (280) an annular gap (410) is formed between the second connector member (280) and the introduced device (100); and the first connector member (180) has an annular groove (187) opening toward the distal end (180a) into which the proximal end (280b) of the second connector member (280) fits when the first connector member (180) and the second connector member (280) are connected. A set according to any one of claims 1 to 4.

6. The first protrusion (185) is disposed on a bottom surface (187a) of the annular groove (187). The set according to claim 5.

7. characterised in that the passage of the device (100), in particular the tube (140) of the device (100), has a side opening (149), which opens into the annular gap (410), in particular in the connected state of the first connector member (180) and the second connector member (280), A set according to claim 5 or 6.

8. the connection between the first connector member (180) and the second connector member (280) is performed by a bayonet lock, preferably characterized in that the engagement of the bayonet lock is tactilely and / or acoustically perceptible; A set according to any one of claims 1 to 7.

9. the stimulation element is designed as an electrically conductive stimulation wire (120) having a diameter (AD), a distal end (120a) and a proximal end (120b); the passageway is designed as an electrically insulating tube (140) having an inner diameter (IS), an outer diameter (AS), a distal end (140a) and a proximal end (140b); The stimulation wire (120) is disposed within the tube (140); the inner diameter (IS) of the tube (140) is greater than the diameter (AD) of the stimulation wire (120), thereby forming a gap (146) in the tube (410) for supplying the fluid; a stimulation electrode (130) is conductively disposed on the distal end (120a) of the stimulation wire (120) and protruding beyond the distal end (140a) of the tube (140), A set according to any one of claims 1 to 8.

10. The proximal end (120b) of the stimulation wire (120) protrudes beyond the proximal end (140b) of the tube (140) and is bent back at the proximal end (140b) of the tube (140) to be guided to the outside of the tube (140); a conductive stimulation cable (150) is conductively connected to the proximal end (120b) of the stimulation wire (120); an infusion tube (160) is partially sealingly fitted onto the proximal end (140b) of the tube (140); The set according to claim 9.

11. The stimulation electrode (130) has a rounded outer surface (132) and is formed, for example, in a hemispherical, spherical, elliptical, mushroom, pear or egg shape. A set according to claim 9 or 10.

12. The stimulation electrode (130) has, in each cross section, an outer diameter (AE) that is equal to or smaller than the outer diameter (AS) of the tube (140), A set according to any one of claims 9 to 11.

13. The stimulation electrode (130) is form-fittingly disposed at the distal end (140a) of the tube (140) by an attachment portion (134); the tube (140) has at least one injection opening in its wall opening into the gap (146) between the stimulation wire (120) and the tube (140) and / or the stimulation electrode (130) has an axial through opening (136), A set according to any one of claims 9 to 12.

14. the proximal end (140b) of the tube (140) is disposed within a housing (170) along with a connection point to the stimulation cable (150) and a connection point to the infusion tube (160); the stimulation cable (150) and the infusion tube (160) are led out of the housing (170) proximally, in particular parallel to the longitudinal axis of the tube (140), and the first connector member (180) is arranged in the housing (170), in particular integrally connected thereto, A set according to any one of claims 9 to 13.

15. characterised in that the diameter (AD) of the stimulation wire (120) is less than 0.3 mm, preferably less than about 0.2 mm, particularly preferably less than 0.1 mm; A set according to any one of claims 9 to 14.

16. The stimulation wire (120) is made of stainless steel. A set according to any one of claims 9 to 15.

17. characterised in that the outer diameter (AS) of the tube (140) is less than 1.0 mm, preferably less than 0.9 mm, and / or the inner diameter (IS) of the tube (140) is in the range of 0.4 mm to 0.7 mm, preferably in the range of 0.5 mm to 0.6 mm, and / or the length (L) of the tube (140) is greater than 5 cm, preferably greater than 8 cm, particularly preferably greater than 10 cm, A set according to any one of claims 9 to 16.

18. characterised in that the tube (140) is made of plastic, for example polyamide, A set according to any one of claims 9 to 17.

19. the set (10) further comprises a rigid cannula (300) having a cannula tube (340) including a distal end (340a) and a proximal end (340b) for insertion into the body, onto which the retention cannula (200) can be fitted prior to insertion, and the rigid cannula (300) has a third connector member (380) at its proximal end (340b) that is complementary to the second connector member (280); by connecting the third connector member (380) and the second connector member (280), the cannula (300) can be fixed in an axial position in which the distal end (340a) of the cannula tube (340) projects beyond the distal end (240a) of the indwelling cannula (200); the third connector member (380) and the second connector member (280) are connected to one another such that a circumferential second seal (500) is formed. A set according to any one of claims 1 to 18.

20. the second seal (500) is formed by abutting a third contact surface (381) of a third connector member (380) against the second contact surface (281) of the second connector member (280), 20. The set according to claim 19.

21. the third connector member (380) having a distal surface (382) with a third axially projecting circumferential projection (385) disposed thereon; the third contact surface (381) is arranged on the outside of the third protrusion (385) and the second contact surface (281) is arranged on the inside of the second protrusion (285), or alternatively, the third contact surface (381) is arranged on the inside of the third protrusion (385) and the second contact surface (281) is arranged on the outside of the second protrusion (285), A set according to claims 3 and 20.

22. characterised in that the third contact surface (381) has a circumferential convexity projecting in the direction of the second contact surface (281) and / or the second contact surface (281) has a circumferential convexity (283) projecting in the direction of the third contact surface (381), 22. A set according to claim 20 or 21.

23. the third connector member (380) has an annular groove (387) that opens toward a distal end (380a), and the proximal end (280b) of the second connector member (280) enters the annular groove (387) when the third connector member (380) and the second connector member (280) are in a connected state; The set according to any one of claims 19 to 22 and claim 5.

24. The third protrusion (385) is disposed on a bottom surface (387a) of the annular groove (387).

24. The set according to claim 23.

25. the cannula tube (340) has a side opening (349) opening into the annular gap (510), particularly in a connected state between the third connector member (380) and the second connector member (280), 25. A set according to claim 23 or 24.

26. the connection between the third connector member (380) and the second connector member (280) is performed by a bayonet lock, preferably characterized in that the engagement of the bayonet lock is tactilely and / or acoustically perceptible; A set according to any one of claims 19 to 25.

27. the cannula tube (340) is made of a conductive material; A conductive stimulation cable (350) is conductively connected to the outside of the cannula tube (340); an infusion tube (360) is partially sealingly fitted onto the proximal end (340b) of the cannula tube (340); A set according to any one of claims 19 to 26.

28. the proximal end (340b) of the cannula tube (340) is disposed within a housing (370) along with a connection point to the stimulation cable (350) and a connection point to the infusion tube (360); the stimulation cable (350) and the infusion tube (360) are led out of the housing (370) proximally, in particular parallel to the longitudinal axis of the cannula tube (340), and the third connector member (380) is arranged in the housing (370), in particular integrally connected thereto.

28. The set according to claim 27.

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