Wrap-sleeve medical implant

Abstract

A medical implant in the form of a wrap sleeve for placement around a nerve fiber bundle is described, the medical implant comprising at least one first flat substrate portion deformable into a hollow cylindrical shape in a rolling direction about a spatial axis specified by a set shape inherent to the material, the first flat substrate portion having an end abutting a first surface of the first flat substrate portion in a rolled state, the first surface oriented to face the area radially enclosed by the rolled first flat substrate portion, and a second flat substrate portion end opposite the first flat substrate portion end, disposed transversely of a second surface of the first flat substrate portion in the rolled state, the second surface oriented opposite the first surface and facing the area radially enclosed by the rolled first flat substrate portion, at least one region of the first flat substrate portion end being monolithically connected to the second flat substrate portion adjacent the second surface of the first flat substrate portion in the rolled state. The present invention is characterized in that the first and second flat substrate portions each have a set shape specific to the material, and each winding direction is oriented in opposite directions relative to the end of the first flat substrate portion.

Description

[Technical Field]

[0001] The present invention relates to a medical implant in the form of a wrap sleeve for placement around a nerve fiber bundle, comprising a flat biocompatible film-like substrate having at least one first flat substrate portion deformable into a hollow cylindrical shape in a rolling direction about a spatial axis specified by a set shape inherent to the material, the first flat substrate portion having an end abutting a first surface of the first flat substrate portion in a rolled state, the first surface oriented to face the area radially enclosed by the rolled first flat substrate portion, and a second flat substrate portion end opposite the end of the first flat substrate portion, arranged transversely of the second surface of the first flat substrate portion in a rolled state, the second surface facing the opposite side of the first surface and facing the area radially enclosed by the rolled first flat substrate portion. [Background technology]

[0002] So-called wrap sleeves, also known as cuff electrodes, are used to apply electrical stimulation signals within the body along nerve fiber bundles. A particularly preferred cuff electrode is disclosed in EP 3204105. To be wrapped around nerve fiber bundles locally, the cuff electrode comprises a flat, biocompatible film substrate, on whose surface an electrode arrangement for applying an electrical signal is provided. This electrode arrangement is in direct surface contact with the epineurium of the nerve fiber bundle. Therefore, the flat film substrate is inherently mechanically tensioned. In an unloaded state, the rectangular flat film substrate automatically winds or rolls around the winding shaft to form a straight, hollow cylindrical shape. Typically, the flat film substrate has a rectangular, flat shape, at least in the region where the material-specific pretension is applied. The free side edges of the flat substrate are guided around the winding shaft at least once, preferably several times, so that the film carrier substrate forms multiple windings of the hollow cylindrical flat substrate that are loosely in contact with each other. The electrode arrangement is applied to the area of ​​the flat substrate surface directly facing the volume enclosed by the wrap sleeve, so that when applied topically around the nerve fiber bundle in an implanted state, it directly contacts the epineurial surface of the nerve fiber bundle. The contact area or pressure between the electrode arrangement and the nerve fiber bundle is supported and / or improved by wrapping the flat substrate multiple times around the nerve fiber bundle, thereby improving the mechanical retention of the nerve fiber bundle's circumference with each additional wrap.

[0003] The radially outermost turns of the flat substrate are mechanically transitioned integrally into a non-pretensioned state, i.e., into a flat flat substrate portion where the electrical contact arrangement is typically provided, and electrical input / output lines connected to the electrode arrangement via the electrical contact arrangement can be connected via corresponding conductor structures to an implantable internal power supply unit which houses both the means for supplying electrical energy to the cuff electrode and for control and operation.

[0004] The conventional method of implanting a cuff electrode requires the surgeon to have high skill and steady hand stability, especially because the cuff electrode autonomously assumes the aforementioned hollow cylindrical rolled state under normal conditions, i.e., when no force is applied. To convert the cuff electrode into an unrolled or unfolded state for application to the outer periphery of a nerve fiber bundle, on the one hand, the cuff electrode must be grasped (preferably with tweezers) by the flat part that is not mechanically pretensioned, and on the other hand, the cuff-shaped rolled flat substrate region must be stretched and flattened by applying a force in the opposite direction to the inherent rolling direction of the material, resulting in an unrolled flat shape of the film-like flat substrate.

[0005] This is accomplished by inserting the short L-arm of the wire device completely through one side of the wound cuff electrode along the winding axis.The device is then clamped with tweezers along the long L-arm of the device, applying an appropriate pulling force to convert the wrap sleeve into an elongated, or stretched, shape.

[0006] The surgeon must perform the above-mentioned procedure using both hands, and maximum concentration is required both when placing the cuff electrode along the nerve fiber bundle and when unwinding the cuff electrode. In particular, if the rollable flat substrate is slightly unfolded, the instrument may slip off or become dislodged from the stretched flat substrate, causing the flat substrate to naturally return to its rolled or unwrapped state. This requires a high level of manual dexterity and surgical experience from the surgeon, especially in a real-life surgical environment where limited space, vision, and time are the only priorities. Furthermore, unsuccessful attempts to place or apply the cuff electrode along the nerve fiber bundle can result in avoidable stress for the patient.

[0007] German Patent Application No. 102018207709 A1 provides a device for extraneural fixation of medical implants with a biocompatible flat substrate, comprising a first substrate part designed as a wrap sleeve with a free end that is loosely radially covered in at least one layer by the wrapped first substrate part by wrapping the first substrate part around a spatial axis. A second substrate part, not wrapped around the spatial axis but integrally adjacent to the first substrate part, is also envisioned and can be directly or indirectly connected to a connecting structure extending away from the medical implant. In the region of the section end, at least one means for joining the first substrate part or the second substrate part, which is wrapped around the spatial axis, is arranged. Summary of the Invention

[0008] The present invention aims to further develop a medical implant in the form of a wrap sleeve for placement around a nerve fiber bundle. The medical implant comprises a flat biocompatible film-like substrate including at least one first flat substrate portion deformable into a hollow cylindrical shape in a winding direction about a spatial axis specified by a predetermined shape inherent to the material, the first flat substrate portion having an end abutting a first surface of the first flat substrate portion in a rolled state, the first surface oriented to face the area radially enclosed by the rolled first flat substrate portion, and a second flat substrate portion end opposite the end of the first flat substrate portion, the second surface oriented transversely of a second surface of the first flat substrate portion in a rolled state, the second surface facing the opposite side of the first surface and facing the area radially enclosed by the rolled first flat substrate portion. This greatly facilitates the surgeon's manipulation when implanting and applying the wrap sleeve to a nerve fiber bundle, virtually eliminating the risk of mishandling or misplacement. Furthermore, the wrap sleeve can be safely and appropriately manipulated even in surgically limited space conditions.

[0009] The solution to the problem underlying the invention is set out in claim 1. Features which advantageously develop the inventive concept are the subject of the dependent claims and the further description, with particular reference to the drawings.

[0010] According to the solution, a medical implant in the form of a wrap sleeve for placement around a nerve fiber bundle having the features of the preamble of claim 1 is characterized in that the first and second flat substrate portions each have a set shape specific to the material with respective winding directions oriented in opposite directions relative to the first flat substrate portion.

[0011] Preferably, the first flat substrate end is formed by folding the flat biocompatible film substrate in a manner that uses creases so that the first and second flat substrate portions lie directly and flat against each other. Preferably, but not necessarily, both flat substrate portions are identical in shape and size or have identical dimensions so that they lie flat and completely against each other when rolled up.

[0012] Also conceivable are embodiments of the second flat substrate portion in which the second flat substrate portion has a smaller area than the first flat substrate portion, e.g., is strip-shaped, and protrudes at least locally beyond the edge of the second flat substrate portion to allow unhindered access to the second flat substrate portion by a grasping tool, e.g., tweezers.

[0013] The first and second flat substrate portions each have a predetermined shape inherent to the material, and both flat substrate portions connected via a common fold line are each autonomously spirally wound around a common winding axis, with the common fold line equivalent to the end of the first flat substrate portion being positioned inside the hollow cylindrical wound shape to be formed. When both flat substrate portions are pulled apart at the end of the flat substrate portion opposite the fold line, for example using two tweezers, it becomes clear that the end of the first flat substrate portion or the ends of both flat substrate portions connected via the fold line and arranged approximately opposite to each other in a stretched state have a predetermined shape inherent to the material and have opposite winding directions.

[0014] To ensure and facilitate safe and reliable handling of the medical implant intended for implantation or application along nerve fiber bundles, the second flat substrate portion end of the first flat substrate portion is monolithically connected to a fourth flat substrate portion that protrudes at least partially beyond the first flat substrate portion in the form of a tab, tongue, or lug.

[0015] The second flat substrate portion is located opposite the first flat substrate portion end designed as a fold and in the rolled state at least partially protrudes beyond the second flat substrate portion end, and / or the fifth flat substrate portion is monolithically connected to a third flat substrate portion end that at least partially protrudes beyond the second flat substrate portion in the form of a tab, tongue or lug.

[0016] In either case, the medical implant can be converted from a rolled state to an open state in which the medical implant can be easily applied locally around nerve fiber bundles by grasping the fourth and fifth tabs or tongue-like flat base portions with a grasping instrument such as tweezers or manually and pulling them apart diametrically. [Brief explanation of the drawings]

[0017] The invention will now be illustrated by way of examples, without limiting the general inventive concept, with reference to the drawings, in which: [Figure 1] Figure 1a, b shows a comparison of the prior art cuff electrode placement (see a) and the solution cuff electrode placement (see b). [Figure 2a] FIG. 2a shows the manufacturing procedure of the cuff electrode according to the present invention and an example of the application of the cuff electrode along a nerve fiber bundle. [Figure 2b] FIG. 2b shows the manufacturing procedure of the cuff electrode according to the present invention and an example of the application of the cuff electrode along a nerve fiber bundle. [Figure 2c] FIG. 2c shows a manufacturing procedure for a cuff electrode according to the present invention and an example of application of the cuff electrode along a nerve fiber bundle. [Figure 2d]FIG. 2d shows the manufacturing procedure of the cuff electrode according to the present invention and an example of the application of the cuff electrode along a nerve fiber bundle. [Figure 2e] FIG. 2e shows the manufacturing procedure of the cuff electrode according to the present invention and an example of the application of the cuff electrode along a nerve fiber bundle. [Figure 2f] FIG. 2f shows the manufacturing procedure of the cuff electrode according to the present invention and an example of the application of the cuff electrode along a nerve fiber bundle. [Figure 2g] FIG. 2g shows the manufacturing procedure of the cuff electrode according to the present invention and an example of the application of the cuff electrode along a nerve fiber bundle. DETAILED DESCRIPTION OF THE INVENTION

[0018] FIG. 1a shows a known cuff electrode, comprising a flat substrate portion 1 made of a flat biocompatible film substrate. Due to the inherent geometry of the material, the first flat substrate portion 1 autonomously assumes a hollow cylindrically wound shape in a predetermined winding direction WS about a spatial axis R. In this wound state, the first flat substrate portion 1 has its surface 3 facing the drawing plane and radially surrounds a cylindrical region 4 from the outside, into which nerve fiber bundles protrude in the implanted state of the cuff electrode. The region of the surface 3 of the first flat substrate portion 1 where the first windings radially surround region 4 is provided with an electrode arrangement 5 that can directly contact the epineurium of the nerve fiber bundles. The first flat substrate portion 1 is preferably flat and rectangular in shape and has a first flat substrate portion end 2, which, in the wound state, loosely contacts the surface 3 of the flat substrate portion 1, as shown in FIG. 1a. In the rolled state, the cuff electrode has at least one complete turn, and preferably multiple turns of the flat substrate are formed, which results in a long-term stable roll shape for the cuff electrode.

[0019] For the sake of completeness, the electrode arrangement 5 is contacted via electrical input / output leads extending into the flat substrate, which is not shown in further detail, and is connected via a further connection structure 6 connected to the first surface substrate portion 1 to an internal power supply unit, which is not the subject of this application and is not shown in further detail.

[0020] In contrast, Figure 1b shows a preferred embodiment of a medical implant designed according to the solution in the form of a wrap sleeve or cuff electrode, which in addition to the known cuff electrode shown in Figure 1a is further monolithically connected along its first flat substrate part end 2 to a so-called second flat substrate part 7, which in the rolled state is loosely in contact with a surface 8 facing away from the surface 3 visible in Figure 1b.

[0021] In the illustrated example, in FIG. 1b, the second flat substrate portion 7 has the same shape and dimensions as the first flat substrate portion 1, thereby radially surrounding the inner region 4 together, and the electrode arrangement 5 arranged on the first flat substrate portion remains facing the inner region 4.

[0022] The first and second flat substrate portions 1, 7 each have a second or third flat substrate end 9, 10 opposite the first flat substrate end 2, which are monolithically connected to tongue-shaped or lug-shaped flat substrate protrusions 11, 12. The flat substrate protrusions 11, 12 are intended to make it easier and more secure to handle the cuff electrode, preferably with a gripping tool such as tweezers.

[0023] Figures 2a to g illustrate the fabrication and handling of a cuff electrode intended for application around a nerve fiber bundle.

[0024] FIG. 2a shows a flat, rectangular biocompatible film substrate. The upper half of the flat substrate in FIG. 2 represents a first flat substrate portion 1 with an electrode arrangement 10 arranged on its surface 3. The lower half, connected to the first flat substrate portion 1 and corresponding to a second flat substrate portion 7, has the same shape and dimensions as the first flat substrate portion 1 in the illustrated example. Both flat substrate portions 1, 7 have the previously described tab- or tongue-like flat substrate projections 11, 12 at their respective flat substrate ends 9, 10. The second flat substrate portion 7 can also be designed with a smaller area; in the rolled state, it is essential that the second flat substrate portion 7 locally protrudes beyond the first flat substrate portion 1 at its flat substrate end 9.

[0025] For the purpose of transmitting and supplying electrical energy and signals to the electrode arrangement 10, the flat substrate part 1 is also provided with a connection structure which is integrated into the flat substrate and which leads to an internal power supply unit (not shown).

[0026] The first and second flat substrate portions 1, 7 are monolithically connected to one another by a so-called first flat substrate portion end 2, which, as further shown, is in the form of a fold.

[0027] Thus, in FIG. 2b, the second flat substrate portion 7 is folded back along and around the edge 2 of the first flat substrate portion (see arrow in FIG. 2b), so that the second flat substrate portion 7 contacts the first flat substrate portion 1 flatly at the back of the electrode arrangement 10 (see FIG. 2c). The first and second flat substrate portions 1, 7, which are in flat contact with each other, are then wound around a spatial axis, starting from the common flat substrate edge designed as a fold, so that the electrode arrangement 10 is always oriented within the radially enclosed area during winding. The wound state is shown in FIG. 2d, where the entire surface of the first and second flat substrate portions 1, 7 is rolled into a cylindrical shape in two layers. To fix the cylindrical shape to the flat biocompatible film substrate in accordance with the material's inherent properties, the wound cuff electrode in the shape shown in FIG. 2d is subjected to an annealing process.

[0028] For the purpose of handling and applying the cuff electrode along the nerve fiber bundle 13 (see FIG. 2e), the cuff electrode is converted into an elongated or slender state by the surgeon grasping the flat substrate projections 11, 12 with an appropriate grasping instrument 14, 15, such as tweezers, and converting the cuff electrode into the extended state as shown in FIG. 2e. In this extended or open state, the surgeon can apply the cuff electrode to a defined surface area of ​​the nerve fiber bundle 13. By reducing the pulling force acting on the cuff electrode, the cuff electrode will autonomously wrap around the nerve fiber bundle 13 (see FIG. 2f). The autonomous wrapping of the cuff electrode around the nerve fiber bundle 13 can be gently controlled by the surgeon using the tweezers 14, 15 to controllably reduce the pulling or holding force.

[0029] Once the cuff electrode is properly positioned along the nerve fiber bundle 13, the inherent restoring forces of the material dominate in the double-layered cuff electrode, allowing it to remain stable over time. This state is shown in Figure 2g. [Explanation of symbols]

[0030] 1: Flat base material 2: First flat substrate edge 3: Surface 4: Area 5: Electrode arrangement 6: Connection structure 7: Second flat substrate portion 8: Opposite side 9: End of second flat substrate portion 10: Third flat substrate end 11:Flat base material protrusion 12: Flat base material protrusion 13: Nerve fiber bundle 14, 15: grasping instruments, e.g., tweezers

Claims

1. A medical implant in the form of a wrap sleeve for placement around a nerve fiber bundle (N), At least one first flat base material portion (1) that is deformable into a hollow cylindrical shape in a winding direction (WS) centered on a spatial axis (R) specified by a set shape inherent to the material, the first flat base material portion end (2) that, when wound, abuts against a first surface (3) of the first flat base material portion (1), and the first surface is oriented so as to face a region (4) radially surrounded by the wound first flat base material portion (1), The invention comprises at least one first flat base material portion (1) located on the opposite side of the first flat base material portion end (2), positioned laterally to the second surface (8) of the first flat base material portion (1) in the rolled state, the second surface facing the opposite side of the first surface (3), and having a second flat base material portion end (9) facing the opposite side of the region (4) radially surrounded by the rolled first flat base material portion (1), The invention comprises a flat, biocompatible film-like substrate, wherein at least one region of the end (2) of the first flat substrate portion is monolithically connected to a second flat substrate portion (7) adjacent to the second surface (6) of the first flat substrate portion (1) in the rolled state, A medical implant characterized in that the first and second flat base material portions (1, 7) each have a shape specific to the material, and the winding direction (WS) is oriented in opposite directions with respect to the end (2) of the first flat base material portion.

2. The medical implant according to claim 1, characterized in that the first flat substrate end (2) has a fold shape due to the folding of the flat biocompatible film-like substrate.

3. The medical implant according to claim 1 or 2, characterized in that the second flat base material portion (7), in the rolled state, has a third flat base material portion end (10) that protrudes at least partially beyond the first flat base material portion (1) along the end (9) of the second flat base material portion.

4. The end (9) of the second flat base material portion of the first flat base material portion (1) is monolithically connected along at least a portion of the area to a flat base material projection (11) that protrudes beyond the first flat base material portion (1). The medical implant according to claim 1, characterized in that the end (10) of the third flat base material portion (7) of the second flat base material portion (7) is monolithically connected along at least a portion of a further flat base material projection (12) that protrudes beyond the first flat base material portion (1).

5. The end (9) of the second flat base material portion of the first flat base material portion (1) is monolithically connected along at least a portion of the area to a flat base material projection (11) which protrudes beyond the first flat base material portion (1), The medical implant according to claim 2, characterized in that the end (10) of the third flat base material portion (7) of the second flat base material portion (7) is monolithically connected along at least a portion of a further flat base material projection (12) that protrudes beyond the first flat base material portion (1).

6. The end (9) of the second flat base material portion of the first flat base material portion (1) is monolithically connected along at least a portion of the area to a flat base material projection (11) which protrudes beyond the first flat base material portion (1), The medical implant according to claim 3, characterized in that the end (10) of the third flat base material portion (7) of the second flat base material portion (7) is monolithically connected along at least a portion of a further flat base material projection (12) that protrudes beyond the first flat base material portion (1).

7. The medical implant according to claim 4 or 5, characterized in that each of the flat base material protrusions has a tab-like shape.

8. The medical implant according to claim 6, characterized in that each of the flat base material protrusions has a tab-like shape.

9. The medical implant according to claim 1 or 2, characterized in that the wrap sleeve is designed as a cuff electrode sleeve having an electrode arrangement (5) on the first flat base material portion (1) and disposed inside thereof, and having at least one freely accessible electrode contact surface on the first surface (3).

10. The medical implant according to claim 3, characterized in that the wrap sleeve is designed as a cuff electrode sleeve having an electrode arrangement (5) on the first flat base material portion (1) and disposed on and inside thereof, and having at least one freely accessible electrode contact surface on the first surface (3).

11. The medical implant according to claim 4 or 5, characterized in that the wrap sleeve is designed as a cuff electrode sleeve having an electrode arrangement (5) on the first flat base material portion (1) and disposed on and inside thereof, and having at least one freely accessible electrode contact surface on the first surface (3).

12. The medical implant according to claim 6, characterized in that the wrap sleeve is designed as a cuff electrode sleeve having an electrode arrangement (5) on the first flat base material portion (1) and disposed on and inside thereof, and having at least one freely accessible electrode contact surface on the first surface (3).

13. The medical implant according to claim 1 or 2, characterized in that the shape of the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) is selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

14. The medical implant according to claim 3, characterized in that the shapes set in particular for the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) are selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

15. The medical implant according to claim 4 or 5, characterized in that the shape of the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) is selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

16. The medical implant according to claim 6, characterized in that the shape of the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) is selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

17. The medical implant according to claim 9, characterized in that the shapes set in particular for the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) are selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

18. The medical implant according to claim 10, characterized in that the shapes set in particular for the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) are selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

19. The medical implant according to claim 11, characterized in that the shapes inherent to the material of the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) are selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

20. The medical implant according to claim 12, characterized in that the shapes set in particular for the flat biocompatible film-like substrate and the first and second flat substrate portions (1, 7) are selected such that, by manual application, the medical implant can autonomously convert from an elongated state in which the first and second flat substrate portions (1, 7) are stretched in opposite directions along a plane under the influence of the tensile force to the rolled state when the tensile force is stopped being applied.

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