Medical implant in form of wound sleeve

Abstract

The invention relates to a medical implant in the form of a wound sleeve for arrangement around a bundle of nerve fibers, comprising a biocompatible planar substrate in the form of a film, which has at least one first planar substrate section, the invention relates to a first planar substrate section which can be converted into a hollow cylindrical shape by winding around a spatial axis in a winding direction predefined by a material-specific shape imprint, said first planar substrate section having a first planar substrate section end and a second planar substrate section end opposite the first planar substrate section end, the end part of the first planar base material section abuts against a first surface of the first planar base material section in a winding state, and the first surface faces a space which is radially enclosed by the wound first planar base material section; the end part of the second planar substrate section is arranged on the side surface of a second surface, deviating from the first surface, of the first planar substrate section in a winding state, and the second surface deviates from a space radially enclosed by the wound first planar substrate section; wherein at least one region of the end of the first planar substrate section is integrally connected to a second planar substrate section which, in the wound state, rests on a second surface of the first planar substrate section. The invention is characterized in that the first and second planar substrate sections each have a material-specific shape imprint, each having a winding direction oriented opposite to the end of the first planar substrate section.

Description

Technical Field

[0001] The present invention relates to a medical implant in the form of a wound sleeve for arrangement around a bundle of nerve fibers, comprising a biocompatible planar substrate constructed in the form of a film, the planar substrate having at least one first planar substrate segment, the first planar substrate segment being capable of being converted into a hollow cylindrical shape by being wound around a spatial axis in a winding direction predetermined by an inherent shape imprint of the material, the first planar substrate segment having a first planar substrate segment end and a second planar substrate segment end opposite to the first planar substrate segment end, the first planar substrate segment end in a wound state abutting against a first surface of the first planar substrate segment, the first surface facing a space radially enclosed by the wound first planar substrate segment, the second planar substrate segment end being arranged in a wound state on a side of a second surface of the first planar substrate segment facing away from the first surface, the second surface facing away from the space radially enclosed by the wound first planar substrate segment. Background Art

[0002] In order to apply electrical stimulation signals along the nerve fiber bundle in vivo, a so-called winding sleeve is used, which is also called a sleeve electrode. EP3204105B1 discloses a particularly preferred sleeve electrode. In order to locally wrap the nerve fiber bundle, the sleeve electrode has a biocompatible planar substrate of thin film construction, on the surface of which an electrode assembly for applying electrical signals is arranged, and the electrode assembly is in direct surface contact with the outer membrane of the nerve fiber bundle. For this purpose, the planar substrate of thin film construction is provided with an inherent mechanical tension, so that the thin film planar substrate, which is originally preferably rectangular, can be independently wound or rolled up around the winding shaft in an originally powerless state, thereby forming a straight hollow cylinder. Usually, the thin film planar substrate is rectangular in planar shape at least in the inherent prestress area of ​​the material, and its free planar substrate side is wound around the winding shaft at least once, preferably several times, wherein the thin film planar substrate forms several loosely adjacent hollow cylindrical planar substrate windings. The electrode assembly is arranged in the area of ​​the surface of the planar substrate directly facing the volume surrounded by the wound cuff so as to be in direct contact with the outer membrane surface of the nerve fiber bundle when implanted and locally applied around the nerve fiber bundle. In order to support or improve the surface contact or contact pressure between the electrode assembly and the nerve fiber bundle, the planar substrate is wound around the nerve fiber bundle several times, so that the mechanical fixation on the periphery of the nerve fiber bundle can be improved as the number of windings increases.

[0003] The radially outermost winding of the planar substrate transitions integrally into a planar substrate section without mechanical prestress (i.e., an originally flat planar substrate section), on which an electrical contact device is usually arranged. Through this electrical contact device, the power supply and output lines connected to the electrode assembly can be connected to the implantable power supply unit through a corresponding conductor structure, in which both a device for power supply and a device for controlling and operating the cuff electrode are installed.

[0004] Until now, the usual practice of implanting sleeve electrodes required the surgeon to have high skills and steady hands, especially since the sleeve electrodes automatically assume the above-mentioned hollow cylindrical rolled state in the normal state, that is, in the powerless state. In order to convert the sleeve electrode into the unrolled or unfolded state so as to be applied to the periphery of the nerve fiber bundle, the sleeve electrode must be picked up in its flat surface area without mechanical prestressing force (preferably using tweezers) on the one hand, and on the other hand, the sleeve-like rolled surface substrate area must be stretched in a surface shape under the action of force against the inherent rolling effect of the material, so that the film-like surface substrate assumes a substantially unrolled surface flat shape.

[0005] To this end, a wire instrument bent into an "L" shape can be used, with the shorter L leg being able to pass completely through the rolled-up cuff electrode on one side along the winding axis. A controlled pulling force is then applied along the longer L leg of the instrument, and appropriate counterforce is applied using forceps to convert the rolled cuff into an elongated, i.e., extended, shape.

[0006] The above process must be completed by the surgeon using both hands, and requires high concentration during the placement and unfolding of the sleeve electrode along the nerve fiber bundle, especially when the rollable planar substrate is stretched even slightly too much, the instrument may slip off or fall off the stretched planar substrate, causing the planar substrate to spontaneously return to the rolled or rolled state. Especially under actual surgical conditions where space, visibility and time are limited, the surgeon's manual skills and surgical experience are very demanding. In addition, incorrect attempts or incorrect application of the sleeve electrode along the nerve fiber bundle is an avoidable burden on the patient.

[0007] The publication DE102018207709A1 describes an extraneural fixation device for a medical implant, which has a biocompatible planar substrate, which has a first planar substrate section in the form of a winding sleeve and a second planar substrate section integrally connected to the first planar substrate section, the first planar substrate section having a free section end, which is loosely radially covered by the wound first planar substrate section by winding the first planar substrate section at least one layer around a spatial axis, the second planar substrate section not being wound around the spatial axis and being directly or indirectly connectable to a connecting structure leading away from the medical implant. At least one device is arranged in the region of the section end, which device forms a bonding connection with the first planar substrate section or with the second planar substrate section when the first planar substrate section is wound around the spatial axis. Summary of the invention

[0008] The object of the present invention is to develop a medical implant in the form of a wound sleeve for arrangement around a bundle of nerve fibers, comprising a biocompatible planar substrate of film-like construction, the planar substrate having at least one first planar substrate section, the first planar substrate section being convertible into a hollow cylindrical shape by being wound around a spatial axis in a winding direction predetermined by a material-inherent shape imprint, and having a first planar substrate section end, the first planar substrate section end in a wound state abutting against a first surface of the first planar substrate section, the first surface facing a space radially enclosed by the wound first planar substrate section, and having a second planar substrate section end opposite the first planar substrate section end, the second planar substrate section end being arranged in the wound state on a side of a second surface of the first planar substrate section facing away from the first surface, the second surface facing away from the space radially enclosed by the wound first planar substrate section, so that the operation of the surgeon when implanting and applying the wound sleeve around the bundle of nerve fibers is significantly simplified, and incorrect operation and incorrect placement can be largely excluded. Furthermore, the cuff should be able to be safely and expertly manipulated in confined surgical spaces.

[0009] The solution to the object addressed by the invention is specified in claim 1. Advantageous features of further developments of the inventive concept can be found in the dependent claims and in the further description, in particular with reference to the drawings.

[0010] According to the solution, a medical implant in the form of a wound sleeve for arrangement around a bundle of nerve fibers has the features of the preamble of claim 1, characterized in that the first and second planar substrate sections each have a material-inherent shape imprint and each have a winding direction opposite to the end of the first planar substrate section.

[0011] Preferably, the first planar substrate section end is formed by folding the film-like biocompatible planar substrate in the manner of a folded edge, so that the first and second planar substrate sections are directly adjacent to each other in planar form. It is not necessary but preferred that the two planar substrate sections have the same shape and size or are of the same dimensions so that they completely abut one another in planar form in the rolled-up state.

[0012] It is also conceivable that the second planar substrate section has a smaller area than the first planar substrate section, for example, is designed in the form of a strip, which at least partially protrudes beyond the end of the second planar substrate section, so that the second planar substrate section can be reached or grasped without hindrance, for example using a grasping tool (such as tweezers).

[0013] The first and second planar substrate sections each have a material-inherent shape imprint, so that the two planar substrate sections connected by a common folding edge are automatically rolled up in a spiral shape around a common winding axis, wherein the common folding edge (which corresponds to the first planar substrate section end) is located inside the hollow cylindrical winding shape. If the two planar substrate sections are pulled apart in opposite directions at the planar substrate section ends opposite the folding edge, for example, using two tweezers, it will be found that the two planar substrate sections (which are connected by the first planar substrate section end or the folding edge and are essentially opposite the folding edge in the stretched state) have a material-inherent shape imprint and have opposite winding directions.

[0014] In order to ensure safe and reliable handling of the medical implant for implantation or application along a bundle of nerve fibers, and also for simplification, the second planar substrate segment end of the first planar substrate segment is integrally connected along at least one segment to a fourth planar substrate segment, which protrudes beyond the first planar substrate segment at least in regions in the manner of a flap, tongue or flag.

[0015] The second planar substrate segment has a third planar substrate segment end opposite to the first planar substrate segment end which is constructed as a folded edge and which in the rolled-up state at least regionally protrudes beyond the second planar substrate segment end or a fifth planar substrate segment is integrally connected along the second planar substrate segment end and which at least regionally protrudes beyond the second planar substrate segment in the manner of a flap, tongue or flag.

[0016] The medical implant can be gripped with a gripping tool (such as tweezers) or manually at the fourth and fifth planar substrate sections, which are each formed in the form of a sheet or tongue, and can be converted from a rolled-up state into an open state by diagonally pulling it apart, in which the medical implant can be conveniently placed locally around a bundle of nerve fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Without limiting the general concept of the present invention, the present invention will be described exemplarily by way of embodiments with reference to the accompanying drawings. In the accompanying drawings:

[0018] 1a, b show a comparison between a sleeve electrode assembly according to the prior art (see a) and a sleeve electrode assembly according to the present solution (see b), and

[0019] FIG. 2 shows a sequence diagram for producing a cuff electrode according to the present solution and for positioning the cuff electrode along a nerve fiber bundle. DETAILED DESCRIPTION

[0020] FIG. 1a shows a known sleeve electrode, which comprises a first planar substrate section 1 composed of a biocompatible planar substrate in the form of a film, which automatically forms a hollow cylindrical winding shape around a spatial axis R by means of a material-inherent shape imprint with a predetermined winding direction WS. In this wound state, the first planar substrate section 1 forms a cylindrical space 4 radially to the periphery with its surface 3 facing the drawing plane, through which the nerve fiber bundles pass in a manner filling up the space when the sleeve electrode is implanted. In a first winding region radially surrounding the space 4, an electrode assembly 5 is arranged on the surface 3 of the first planar substrate section 1, which electrode assembly can be in direct contact with the outer membrane of the nerve fiber bundle. The first planar substrate section 1 is preferably planar and rectangular and has a first planar substrate section end 2, which (as shown in FIG. 1a) in the wound state loosely rests on the surface 3 of the planar substrate section 1. In the wound state, the sleeve electrode has at least one complete winding, preferably forming a multi-planar substrate winding, in order to obtain a long-term stable sleeve electrode winding shape.

[0021] For the sake of completeness, it should be pointed out that the electrode assembly 5 is contacted via power supply and power outflow lines, not further shown, extending within the planar substrate, which are connected via a connecting structure 6 that is further guided and connected to the first planar substrate section 1 to an implantable supply unit, not further shown, which is not the subject of the present application.

[0022] In contrast, Figure 1b 1 shows a preferred embodiment of a medical implant according to the present solution in the form of a wound sleeve or sleeve electrode, which, in addition to the known sleeve electrode shown in FIG. 1a, is integrally connected along its first planar substrate section end 2 to a further, so-called second planar substrate section 7, which in the wound state rests loosely against the substrate facing away from the first planar substrate section. Figure 1b On surface 8 of surface 3 shown.

[0023] exist Figure 1bIn the case shown, the second planar substrate section 7 has the same shape and size as the first planar substrate section 1 and together with it radially encloses the interior 4 , wherein the electrode assembly 5 applied to the first planar substrate section 1 still remains facing the interior 4 .

[0024] The first and second planar substrate sections 1, 7 each have a second or third planar substrate section end 9, 10 opposite the first planar substrate section end 2, which is respectively connected in one piece to a tongue-shaped or flag-shaped planar substrate extension 11, 12. The planar substrate extensions 11, 12 serve to simplify and safely handle the cuff electrode, preferably with the aid of a gripping tool, for example with tweezers.

[0025] Figure 2a Figures 1 to 4 show the fabrication and operation of a cuff electrode for applying around a nerve fiber bundle.

[0026] Figure 2a A biocompatible planar substrate in the form of a film is shown which has a flat rectangular shape. Figure 2a The upper half of the planar substrate shown in the figure represents the first planar substrate segment 1, on whose surface 3 an electrode assembly 5 is arranged. The lower half connected in one piece to the first planar substrate segment 1 corresponds to the second planar substrate segment 7, which, as shown in the figure, has the same size and dimensions as the first planar substrate segment 1. Both planar substrate segments 1, 7 have the above-mentioned sheet-like or tongue-like planar substrate continuations 11, 12 at their respective planar substrate segment ends 9, 10. The area of ​​the second planar substrate segment 7 can also be smaller, and what is important is that in the wound state, the second planar substrate segment 7 partially protrudes beyond the first planar substrate segment 1 at the planar substrate segment end 9.

[0027] For the transmission of electrical energy and signals and for the supply of power to electrode assembly 10 , a connecting structure 6 is additionally arranged on first planar substrate section 1 , which connecting structure is integrated in the planar substrate and leads to an implantable supply unit (not shown in greater detail).

[0028] The first and second planar substrate sections 1 , 7 are integrally connected via a so-called first planar substrate section end 2 , which, as will be shown below, corresponds to a bending or folding edge.

[0029] Therefore, in Figure 2b In the embodiment, the second planar substrate section 7 is bent or folded back along and around the first planar substrate section end 2 (see Figure 2b ), so that the second planar substrate segment 7 is placed flat against the first planar substrate segment 1 on the rear side of the electrode assembly 5 (see arrow in FIG. Figure 2c). In addition, the two first and second planar substrate sections 1, 7, which are flatly abutting each other, are wound around the spatial axis starting from their common first planar substrate section end which is configured as a fold edge, so that the electrode assembly 5 still faces the space radially enclosed during winding. Figure 2d 1 and 2 show the wound state. In this figure, the entire surface area of ​​the first and second planar substrate sections 1, 7 is rolled together in the form of a two-layer cylinder. In order to imprint the cylindrical shape in a material-inherent manner in the biocompatible planar substrate of film-like construction, the wound sleeve electrode is arranged according to Figure 2d The form shown is tempered.

[0030] In order to manipulate and apply the cuff electrode along the nerve fiber bundle 13 (see Figure 2e ), the surgeon grasps the planar substrate extensions 11, 12 with the aid of suitable grasping tools 14, 15 (e.g. tweezers) and switches the sleeve electrode to an extended state (e.g. Figure 2e ), thereby converting the sleeve electrode to an extended state. In this extended or open state, the surgeon can apply the sleeve electrode to a determined surface area of ​​the nerve fiber bundle 13. By reducing the tension acting on the sleeve electrode, the sleeve electrode will automatically wrap around the nerve fiber bundle 13 (see Figure 2f The automatic rolling-in process of the sleeve electrode around the nerve fiber bundle 13 can be controlled in a metered manner by the surgeon reducing the pulling or holding force in a controlled manner by means of the forceps 14 , 15 .

[0031] Once the cuff electrode is placed at the correct position along the nerve fiber bundle 13, the cuff electrode will remain stable for a long time due to the inherent restoring force of the material present in the double-layer cuff electrode. Figure 2g This status is shown.

[0032] List of reference numerals:

[0033] 1 Surface substrate

[0034] 2 End of first planar substrate

[0035] 3 Surface

[0036] 4. Space

[0037] 5 Electrode assembly

[0038] 6 Connection structure

[0039] 7 Second planar substrate section

[0040] 8 Opposite surfaces

[0041] 9 Second planar substrate segment end

[0042] 10 End of the third planar substrate segment

[0043] 11 Continuation of planar substrate

[0044] 12 Continuation of planar substrate

[0045] 13 Nerve fiber bundles

[0046] 14, 15 Grasping tools, such as tweezers.

Claims

1. A medical implant in the form of a wound cuff for arrangement around a bundle of nerve fibers (N), comprising a biocompatible planar substrate of film-like construction, the planar substrate having at least one first planar substrate section (1) which can be converted into a hollow cylindrical shape by winding around a spatial axis (R) in a winding direction (WS) predetermined by the inherent shape of the material, the first planar substrate section having a first planar substrate section end (2) and a second planar substrate section end (9) opposite the first planar substrate section end (2), the first planar substrate section end in the wound state resting against the first planar substrate section. (1), the first surface facing the space (4) radially enclosed by the first planar substrate segment (1) after winding, the second planar substrate segment end in the wound state is arranged on the side of the second surface (8) of the first planar substrate segment (1) facing away from the first surface (3), the second surface facing away from the space (4) radially enclosed by the first planar substrate segment (1), wherein at least one area of ​​the first planar substrate segment end (2) is integrally connected to the second planar substrate segment (7), and the second planar substrate segment abuts against the second surface (6) of the first planar substrate segment (1) in the wound state, It is characterized in that The first and second planar substrate sections (1, 7) each have a material-inherent shape imprint and each have a winding direction (WS) oriented oppositely to the first planar substrate section end (2).

2. The medical implant according to claim 1, characterized in that The first planar substrate section end (2) is formed by folding the film-like biocompatible planar substrate in the manner of a folded edge.

3. The medical implant according to claim 1 or 2, characterized in that The second planar substrate segment (7) has a third planar substrate segment end (10) which, in the wound state, projects beyond the first planar substrate segment (1) at least in regions along the second planar substrate segment end (9) of the first planar substrate segment.

4. The medical implant according to any one of claims 1 to 3, characterized in that The second planar substrate segment end (9) of the first planar substrate segment (1) is integrally connected along at least one segment to a planar substrate continuation (11), which protrudes beyond the first planar substrate segment (1) at least in regions, and A third planar substrate segment end (10) of the second planar substrate segment (7) is integrally connected along at least one segment to a further planar substrate continuation (12), which projects beyond the first planar substrate segment (1) at least in regions.

5. The medical implant according to claim 4, characterized in that The planar substrate extensions are each configured in a sheet shape.

6. The medical implant according to any one of claims 1 to 5, characterized in that The wound sleeve is designed as a sleeve electrode sleeve and comprises an electrode component (5) arranged on and in the first planar substrate section (1), the electrode component having at least one electrode contact surface which is freely accessible on the first surface (3).

7. The medical implant according to any one of claims 1 to 6, characterized in that The material-inherent shape imprints in the film-like biocompatible planar substrate and in the first and second planar substrate sections (1, 7) are selected so that the medical implant can be automatically converted from an extended state to a rolled-up state by terminating the tensile force by manually applying the biocompatible planar substrate. In the extended state, the first and second planar substrate sections (1, 7) are extended in opposite directions along a plane under the tensile force.

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