Device for fixation of medical implants in the form of coiled sleeves outside blood vessels or outside neurons

Abstract

A device for fixating a medical implant outside a blood vessel or outside a neuron is described, which has a biocompatible surface substrate, which has a first substrate segment designed in the form of a winding sleeve, which has a free segment end, which is radially covered loosely by the wound first substrate segment at least in a single layer by the first substrate segment being wound around a spatial axis, and a second substrate segment connected integrally to the first substrate segment, which is not wound around the spatial axis and can be connected directly or indirectly to a connecting structure extending away from the medical implant. The invention is characterized in that at least one component is arranged in the region of the segment end, which component establishes a joint connection with the first substrate segment and / or the second substrate segment when the first substrate segment is wound around the spatial axis.

Description

Technical Field

[0001] The present invention relates to a device for fixing a medical implant outside a blood vessel or outside a neuron, which has a biocompatible surface substrate, which is provided with: a first substrate segment constructed in the form of a winding sleeve, the first substrate segment having a free segment end, the segment end being radially covered by the wound first substrate segment in a loose manner at least in a single layer by winding the first substrate segment around a spatial axis; and a second substrate segment integrally connected to the first substrate segment and not wound around the spatial axis, the second substrate segment being capable of being directly or indirectly connected to a connecting structure extending away from the medical implant. Background Art

[0002] A medical implant of this type is described in the publication WO 2016 / 055512 A1 and schematically shown in FIG. 2 , which is designed in the form of a winding sleeve for detecting and also applying neural electrical signals and is suitable for being retained permanently or at least for a long time along a bundle of nerve fibers in the body of a human or an animal. The medical implant 1 made of a biocompatible surface substrate 2 and designed as a winding sleeve has a first substrate section 3, which is wound around a spatial axis 5 while forming at least one turn of the surface substrate roll, which radially surrounds a straight cylindrical cavity H. A plurality of electrode surfaces, not shown in FIG. 2 , are arranged on the surface substrate surface facing the straight cylindrical cavity H, which electrode surfaces are in physical contact with the epineurium of the bundle of nerve fibers surrounded by the winding sleeve 1, which are also not shown in FIG. 2 . In order to ensure that the medical implant 1 is retained as fixedly as possible along the nerve fiber bundle after the corresponding implantation and can move with the natural shape changes of the nerve fiber bundle or at least without any significant mechanical resistance to the nerve fiber bundle, the base rolls of the individual ring surfaces rest loosely against one another and can increase the diameter of the enclosed cavity H when the nerve fiber bundle expands due to the corresponding relative movement.

[0003] Due to the material prestress applied to the surface substrate 2 in the first substrate segment 3, the surface substrate 2 adopts a predetermined winding shape when no external force is applied, in which the free segment end 4 is radially covered by the first substrate segment, i.e., by at least one turn of the surface substrate roll, in a loose manner at least in a single layer.

[0004] A second base section 6, which is not wound around the spatial axis 5, is connected in one piece to the wound first base section 3, within which electrical lines are guided, which are connected to a plurality of electrodes which are in contact with the epineurium of the nerve fiber bundles. The second base section 6, which is also designed in a planar manner, has in the illustrated embodiment a web-shaped surface section 6 oriented parallel to the spatial axis 5, which is connected via an interface S (not shown in further detail), for example in the form of an implantable plug connection, to a connecting structure 7 extending away from the medical implant 1, along which the electrical lines are guided to a separate, preferably implantable, power supply unit.

[0005] In the unloaded state, the medical implant 1 is in a situation where the first base section 3 formed as a winding sleeve is surrounded in the same diameter along the nerve fiber bundle N according to the schematic view in FIG. 3a. In this state, no or only minimal mechanical external forces act on the nerve fiber bundle N. On the contrary, if an external force F acts on the medical implant 1, which is caused, for example, by the movement of the body, it can cause the coil geometry to deform along the first base section 3 configured as a winding sleeve, thereby on the one hand, it may no longer be possible to ensure the fixation of the medical implant along the nerve fiber bundle N, and on the other hand, the mechanical pressure caused by the medical implant may act on the nerve fiber bundle. In FIGS. 3b to e, a schematic diagram of such a load situation is drawn. Therefore, for example, a tensile force F oriented substantially parallel to the longitudinal extension of the nerve fiber bundle N causes a funnel-shaped deformation inside the winding sleeve, which on the one hand causes a compression E on the nerve fiber bundle N and on the other hand causes an expansion A of the winding sleeve from the nerve fiber bundle N and thus causes a corresponding radial spacing, see FIGS. 3b and c for this. Likewise, in the case of a force F directed perpendicularly to the longitudinal extension of the nerve fiber bundle acting on the medical implant 1, a compression E of the nerve fiber bundle N can result, see the load case in FIG3 d . In this case, the force F acts as a tensile force transversely to the nerve fiber bundle N. In FIG3 e , the force F acts in the opposite direction of force action in the form of a thrust directed toward the nerve fiber bundle N, whereby the winding sleeve expands in diameter and tends to come loose from the nerve fiber bundle N.

[0006] A rolled electrode is shown in its original form in DE 44 33 111 A1, which has an interdigitated surface shape, the individual finger sections of which are deformed in an opening manner as a result of external pressure and force loads.

[0007] The publication US Pat. No. 4,602,624 discloses an implantable sleeve electrode having a surface base which is wound into a hollow cylindrical shape and has different inner diameters in the axial longitudinal extension. The hollow cylindrical shape is maintained only by the prestressing force predetermined by the material itself.

[0008] The publication WO 2013 / 150524 A1 discloses an electrode sleeve arrangement having a row of individual metal sleeves serving as electrodes, which are generally surrounded radially from the outside by an outer housing which can be transferred from an open state into a closed state, the latter being ensured by means of a closing clamp. Summary of the invention

[0009] The object of the present invention is a device for the extravascular or extraneural fixation of a medical implant, which has a biocompatible surface substrate, which has a first substrate section designed in the form of a winding sleeve, which has free segment ends, which are radially covered loosely by the wound first substrate section at least in a single layer by the winding of the first substrate section around a spatial axis; and a second substrate section connected integrally to the first substrate section, which is not wound around the spatial axis and can be directly or indirectly connected to a connecting structure extending away from the medical implant, the device being further developed in such a way that a reliable and at the same time safe, comfortable and permanent placement of the medical implant along the internal blood vessels or nerve fiber bundles is possible. The measures to be met should avoid or at least reduce deformations of the winding sleeve due to movement so that no significant mechanical loads are applied to the internal blood vessels or nerve fiber bundles. The measures to be met should not cause significant additional time and also operating technology expenditures for the surgeon within the framework of the implantation.

[0010] The solution to the object on which the invention is based is specified in claim 1. Features which further develop the solution concept in an advantageous manner can be gathered from the content of the dependent claims and from the further description, in particular with reference to concrete exemplary embodiments.

[0011] According to the solution, a device for fixing a medical implant outside a blood vessel or outside a neuron has a biocompatible surface substrate, which is constructed in the form of a winding sleeve and has the features of the preamble of claim 1, wherein at least one component is arranged in the area of ​​a segment end of a first substrate segment constructed as a winding sleeve, which establishes a joining connection with the first substrate segment and / or the second substrate segment spatially separated from the segment end when the first substrate segment is wound around a spatial axis.

[0012] According to the solution, the free segment end of the first substrate segment wound into a winding sleeve is releasably fixedly connected to an area of ​​the carrier substrate, preferably located inside the second substrate area, i.e. the following area of ​​the carrier substrate, which is integrally connected to the first substrate segment constructed in the form of a winding sleeve, via at least a component that transmits tensile forces. At least one component is arranged and constructed in such a way that it generates a holding or supporting force in the event of forces acting externally on the medical implant, by which the shape and contour of the winding sleeve are kept unchanged. At least one component can transmit tensile forces in particular between the free segment end and the joining area. In principle, it is also conceivable that the joining area is arranged inside the first substrate segment, but in this case it should be noted that at least one complete winding of the first substrate segment around the spatial axis extends between the area of ​​the segment end on which the component is arranged on one side and the joining connection.

[0013] In a preferred embodiment, at least one component is designed in the form of a flexible and inextensible bundle, preferably in the form of a wire or a strip. The bundle is fixedly joined at one of its two bundle ends in the region of the segment end of the first substrate segment or is integrally connected to this region. The other end of the bundle is fixed in the region of the first and / or second substrate segment by a releasably fixed joining connection, preferably in the form of a force-fitting and / or form-fitting connection. In an advantageous manner, the biocompatible surface substrate has at least one fixing opening that completely penetrates the surface substrate in the region of the first and / or second substrate segment, through which the bundle can be passed for a releasably fixed connection, preferably for forming a knot.

[0014] In a further embodiment, the component is designed in the form of a tab which projects laterally beyond the first base section in the region of the segment ends and is connected integrally thereto. A slit-shaped recess is provided along the first or second base section, into which the tab can engage while forming a force-fitting and / or form-fitting connection. The slit-shaped recess is preferably located within a region of the first or second base section which projects beyond the first base section which is designed as a winding sleeve in the longitudinal extension of the winding. A more detailed description of this will be found in the following description with reference to specific exemplary embodiments.

[0015] In principle, the first base segment has a winding longitudinal extension oriented about the spatial axis and a sleeve longitudinal extension oriented axially relative to the spatial axis, wherein the winding longitudinal extension is determined by the spacing between the free segment end and a second base segment adjoining the first base segment. In a preferred embodiment, the sleeve longitudinal extension narrows stepwise, preferably uniformly, along the winding extension within the first base segment at a spacing that increases in the region of the segment end. Thus, the opposite ends of the segment ends are freely accessible axially from the outside in the winding shape of the first base segment, so that the bundle can extend unhindered from the respectively opposite ends of the segment ends to the joining region.

[0016] Other aspects and features according to the solution can be learned from the further description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is exemplarily described below based on embodiments with reference to the accompanying drawings without limiting the general concept of the present invention. In the accompanying drawings:

[0018] Figure 1a An embodiment according to the solution with a single connecting piece is shown.

[0019] Figure 1b , c shows an embodiment according to the solution with two connecting pieces in each case,

[0020] FIG. 2 shows a medical implant with a winding sleeve according to the prior art,

[0021] 3a-e show various loading states of a medical implant in the form of a wound sleeve,

[0022] Figure 4a , c shows an embodiment of the solution with tab fastening on both sides, and

[0023] Figure 5a , b shows an embodiment according to the solution with an end region freely accessible on both sides along the free segment end. DETAILED DESCRIPTION

[0024] Figure 1a The medical implant 1 is shown with a flat substrate 2, the first substrate section 3 of which forms a winding sleeve, ie the free section end 4 of the first substrate section 3 is wound around a spatial axis 5 to form a coil of at least one turn. Figure 1a Implementation 2 1 / 2 The unwound second base section 6 is connected to the first base section 3 in one piece.

[0025] The bundle 8, preferably in the form of a wire, a belt or a similar tensile force transmitting component, is fixedly arranged in the middle along the free segment end 4. The fixed connection 10 is designed as a material, force and / or shape-fitting, non-releasable connection. Starting from the position of the connection 10, the bundle 8 extends through an opening 11 machined into the interior of the first base segment 3, which radially overlaps in the shown winding state. The bundle 8 crosses the winding sleeve from the inside to the outside in the described manner. The bundle end opposite the connection 10 is partially connected to the second base segment 6 within the framework of a releasably fixed joint connection 12. An opening 13 is provided on the surface base 2 in the area of ​​the joint connection 12, through which the bundle 8 is guided and connected to the second base segment 6 by preferably tying a knot.

[0026] By arranging the bundle 8 in the middle of the segment end 4 along the sleeve longitudinal extension L, the tensile force is evenly transmitted to the segment end 4 along the bundle 8 and prevents the winding sleeve from unwinding. In addition, uneven load conditions such as shown in Figures 3b and c are avoided by uniform force transmission.

[0027] Figure 1b The embodiment shown in FIG. 1 provides two separate bundles 8 in the form of surgical threads instead of a single bundle, which are fixedly joined on one side to the ends 41, 42 of the free segment end 4 of the first base segment 3. The two bundles 8 are attached to the second base segment 6 at their free ends 81, 82 via a releasably fixed joint connection 9. In this case, too, openings that penetrate the flat base 2 are provided in the second base segment 6 in each case to form the joint connection 9.

[0028] Figure 1c An embodiment is shown which, instead of two linear bundles, provides two strip-shaped bundles 8 which are each integrally connected to the ends 41, 42 of the free segment ends 4 of the first base segment 3. The opposite strip ends 81, 82 extend into corresponding slit-shaped recesses 13 within the surface base 2 of the second base segment 6 and are detachably fixedly connected to the second base segment.

[0029] Figure 4a1 and 2 show a medical implant 1 in a three-dimensional oblique view (see a) and in a plan view (see b) in an unwound state. In this case, the segment ends 4 of the first base segment 3 each have two tabs 14 protruding laterally from the first base segment 3, which, in the wound state of the first base segment 3, extend into a slit-shaped recess 15 respectively arranged on the second base segment 6 while forming a releasably fixed force-locking and form-locking connection. The slit-shaped recess 15 is located in a lateral region 16 (see hatched area) of the respective second base segment 6, which protrudes on both sides beyond the sleeve longitudinal extension L. The tabs 14 cooperating with the slit-shaped recess 5 prevent the wound sleeve from uncontrolled loosening from the nerve fiber bundle, as with the linear or strip-shaped bundle 8. At the same time, the slit-shaped recess 15 has a slit length 17 which is dimensioned to be greater than the web width so that the web 14 can be moved limitedly along the slit-shaped recess 15 and the winding sleeve can follow the natural deformation or expansion of the nerve fiber bundle.

[0030] Figure 5a , b shows an alternative embodiment for implementing the fixed precautions according to the solution. Figure 5a A plan view of the surface base 2 of the winding sleeve is shown in the unwound state, Figure 5b A perspective view of a medical implant in the form of a wound sleeve is shown. The first base section 3 is designed in a trapezoidal manner so that the sleeve longitudinal extension L narrows uniformly along the winding extension W within the first base section 3 at an increasing distance from the region of the section end 4, for which purpose see Figure 5a 3. By winding the first base section 3 around the spatial axis 5, the ends 41, 42 of the free end section 4 of the first base section 3 can be freely accessible to the outside on one side, for which see Figure 5b In this way, the linear or strip-shaped bundle 8 can be fixedly joined to the ends 41, 42 in an uncomplicated manner. The opposite ends of the bundle 8 are releasably fixedly joined in the region of the second base section 6, as in the previous embodiment. For this purpose, the opening 13 is used, through which the end section of the bundle 8 can be guided and tied accordingly.

[0031] It is of course possible that the measures described in the preceding exemplary embodiments can be combined with one another.

[0032] Reference numerals list

[0033] 1 Medical implants

[0034] 2-sided base

[0035] 3 First basal segment

[0036] 4 Free segment ends

[0037] 41, 42 End of the segment end

[0038] 5 Spatial Axis

[0039] 6 Second basal segment

[0040] 61 Surface section designed in a web-like manner

[0041] 7 Connection structure

[0042] 8 Bundles

[0043] 9. Joint connection

[0044] 10. Connect

[0045] 11 Opening

[0046] 12 Joint connection

[0047] 13 Opening

[0048] 14. Splice

[0049] 15 Slit-like gap

[0050] 16 Lateral area

[0051] 17 Length of the slit-shaped gap

[0052] S-Mount

[0053] H cylindrical cavity

[0054] E Compression

[0055] A. Expansion

[0056] W Wrap extension

[0057] L sleeve longitudinal extension

[0058] N Nerve fiber bundle

[0059] F External force

Claims

1. A device for fixing a medical implant (1) outside a blood vessel or outside a neuron, comprising a biocompatible surface substrate (2), the surface substrate having: a first substrate segment (3) constructed in the form of a winding sleeve, the first substrate segment having a free segment end (4), the segment end being radially covered by the wound first substrate segment (3) in a loose manner at least in a single layer by winding the first substrate segment (3) around a spatial axis (5); and a second substrate segment (6) connected integrally to the first substrate segment (3) and not wound around the spatial axis (5), the second substrate segment being directly or indirectly connectable to a connecting structure (7) extending away from the medical implant (1), It is characterized in that At least one component (8) is arranged in the region of the segment end (4), which component establishes a joining connection (9) with the first base segment (3) and / or the second base segment (6) when the first base segment (3) is wound around the spatial axis (5).

2. The device according to claim 1, characterized in that In the wound state of the first base section (3), a region of the first base section (3) extending at least once around the spatial axis (5) extends between a region of the section end (4) on which the component (8) is arranged and the joining connection (9).

3. The device according to claim 1 or 2, characterized in that: The joint connection (9) is releasably fastened.

4. The device according to claim 1 or 2, characterized in that: The joint connection (9) is a force-locking and / or form-locking connection.

5. The device according to claim 1 or 2, characterized in that: The component (8) is a bundle that transmits tensile forces and is fixedly mounted on one side in the region of the segment end (4) or is integrally connected to this region.

6. The device according to claim 1 or 2, characterized in that: The biocompatible surface substrate (2) has at least one fastening opening (11) which passes completely through the surface substrate (2) and through which the component (8) is guided for the joint connection (9).

7. The device according to claim 1 or 2, characterized in that: The component (8) is designed in the form of a web which protrudes laterally beyond the first base section (3) and on which a slit-shaped recess is arranged and configured so that the web can engage in the slit-shaped recess while forming a joint connection.

8. The device according to claim 1 or 2, characterized in that: The first base segment (3) has a winding extension (W) oriented around the spatial axis (5) and a sleeve longitudinal extension (L) oriented axially relative to the spatial direction, and the sleeve longitudinal extension (L) narrows stepwise or uniformly along the winding extension (W) at an increasing distance from the segment end (4) within the first base segment (3).

9. The device according to claim 1 or 2, characterized in that: The free segment end (4) of the first base segment (3) has two areas (41, 42) lying opposite each other along the segment end (4), in which one of the components (8) is respectively arranged, and the joining connections (9) of the two components (8) are arranged opposite each other along the spatial axis (5) in the first base segment (3) and / or in the second base segment (6).

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