Medical implant having an electrical line arrangement with a longitudinal extent

Abstract

The invention relates to a medical implant having an electrical line arrangement with a longitudinal extent, comprising a sheet-like, strip-shaped planar substrate which is made of a flexible and non-elastic material and on and / or in which a number of electrical conductors are arranged, wherein along the longitudinal extent of said conductors the electrical line arrangement is mechanically and electrically connected at one end to an array that applies and / or senses signals and, at the longitudinally opposite end, to a rigid connecting structure such that it is movable with respect to the structure, wherein at least in a longitudinal portion connected at one end to the connecting structure the sheet-like, strip-shaped planar substrate of the electrical line arrangement has an undulating shape characterised by a sequence of at least one wave crest and one wave trough which extend orthogonally with respect to an otherwise flat surface of the sheet-like, strip-shaped planar substrate. The invention is characterised in that at least the longitudinal portion of the sheet-like, strip-shaped planar substrate of the electrical line arrangement which at one end is connected to the connecting structure, as well as at least part of said connecting structure, are surrounded in a fluid-tight manner by an elastic sheathing.

Description

[0001] Medical implant with an electrical conductor arrangement extending over a longitudinal area

[0002] Technical field

[0003] The invention relates to a medical implant with a longitudinally extending electrical conductor arrangement comprising a film-like, ribbon-shaped surface substrate made of a flexible and non-elastic material, on and / or in which a number of electrical conductors are arranged, and along its longitudinal extent the electrical conductor arrangement is mechanically and electrically connected, and relative to it, to a signal-applying and / or sensor-detecting arrangement on one side and to a rigid connecting structure opposite the latter on the other side, wherein the film-like, ribbon-shaped surface substrate of the electrical conductor arrangement has a wavy shape structure, characterized by a sequence of at least one wave crest and one wave trough, at least in one longitudinal section connected to the connecting structure on one side.which extend orthogonally to an otherwise flat surface of the foil-like, ribbon-shaped substrate.

[0004] State of the art

[0005] Implants designed for permanent or long-term indwelling are typically used to therapeutically influence organ function. Well-known examples include cardiac and cerebral pacemakers. Depending on their intended use and the complexity of the therapeutic goal, such implants have a variety of electrical conductors through which they receive electrical control signals and electrical energy. The intracorporeal placement of the control unit and the power source, which typically form a single implantable component, is usually subcutaneous, in a body region such as the chest or near the collarbone, where the patient experiences minimal external and internal stresses from movement and where surgical access is easily possible.In contrast, the medically active implant is attached separately from the control unit and the energy source at the location or at least in the immediate vicinity of an organ, vessel, nerve bundle, etc., where the therapeutic measure is to be carried out.

[0006] Using the example of an implantable cuff electrode arrangement supplied via a multipole supply and drainage structure, as disclosed in publication DE 10 2014 014 927 A1, the existing problem will be explained in more detail with reference to Figure 4.

[0007] Figure 4 shows an electrical implant in the form of a cuff electrode assembly 1, designed as a coiled electrode for encircling a nerve fiber bundle 2. For the purpose of therapeutic stimulation of the nerve fiber bundle 2, the cuff electrode assembly 1 provides a plurality of individual electrode surfaces applied to the surface of a film-like substrate 4, which lies directly against the nerve fiber bundle 2, forming at least one coil around a winding axis. The electrode surfaces, which are not visible in Figure 4, are supplied separately with electrical energy and control signals. For this purpose, each electrode surface is connected to electrical conductors 3 running within the flexible substrate 4, which is preferably designed as a polyimide film and is otherwise inelastic. The electrical conductors 3 typically terminate at a connection structure 5, e.g.in the form of a plug connection or a non-removable electrical contact structure, from which a cable harness 6, comprising the electrical conductors 3, leads to a separate intracorporeally arranged supply unit 7. Almost incessant and inherent body movements also change the relative position between the individual implanted components, in particular the relative position between the cuff electrode assembly 1 and the supply unit 7. The connection between the film-like, flexible surface substrate 4 and the mechanically rigid connection structure 5 proves to be a particularly critical area due to the relative movements and the resulting mechanical (continuous) loads acting on the implanted components. In this area, the film-like surface substrate 4 is ribbon-shaped, has a longitudinal extension, and is, on the one hand, a single piece, i.e.,monolithically, the cuff electrode arrangement 1 and the rigid connection structure 5 are mechanically and electrically connected, as well as being movably relative to it. Besides the movement-induced deformations oriented along the surface normal of the film-like substrate, which lead to virtually harmless surface deflections of the substrate, it is primarily deformations that develop along the substrate and perpendicular to the surface normal that generate shear forces within the substrate, particularly at the connection point to the supply unit.

[0008] In addition, tensile forces Z develop along the cable 6 due to movement, placing the entire component string under further mechanical stress. To counteract such tensile stress, German patent application DE 10 2028 213 119 A1 proposes providing the ribbon-shaped, film-like surface substrate 4, which connects the cuff electrode arrangement 1 to the connecting structure, with a helical, wavy, meandering, or zigzag-like structure, so that the ribbon-shaped, film-like surface substrate 4 can be transformed from an initial state to a state stretched relative to the initial state and back again. For easier handling when attaching the cuff electrode arrangement 1 to a nerve strand and to maintain its shape, the structured ribbon-shaped, film-like surface substrate 4 is enclosed in an elastic sheath.

[0009] In long-term studies on generic medical implants, it was nevertheless observed in individual cases that the foil-like surface substrate 4 began to form microcracks in the immediate vicinity of the rigid connecting structure 5, which can develop into a damage scenario in which the function and operational safety of the entire implant can be called into question.

[0010] In publication DE 102004 035 002 A1, an electrical connecting cable for implantable components is disclosed which has a wave-like shape in the unloaded state in order to improve the flexibility of an elastic flat ribbon cable.

[0011] The publication EP 3292 885 A1 discloses a stretchable electrode conductor arrangement for a medical implant, which provides a plurality of conductors applied to a non-stretchable carrier material and is cut in a zigzag or meander shape to adapt to the contour of the conductors.

[0012] Description of the invention

[0013] The invention is based on the objective of providing a medical implant with a longitudinally extending electrical conductor arrangement comprising a film-like surface substrate made of a flexible and non-elastic material, on and / or in which a number of electrical conductors are arranged, and which, along its longitudinal extent, is mechanically and electrically connected, and relative to it, to a signal-applying and / or sensor-detecting arrangement on the one hand, and to a rigid connecting structure opposite this arrangement on the other, wherein the film-like, ribbon-shaped surface substrate of the electrical conductor arrangement has a wavy shape structure, characterized by a sequence of at least one wave crest and one wave trough, at least in a longitudinal section connected to the connecting structure on one side.which extend orthogonally to an otherwise flat surface of the foil-like, ribbon-shaped substrate, to further develop in such a way as to avoid or at least significantly reduce movement-related material weakening that leads to irreversible material damage and ultimately to a resulting loss of function of the medical implant, in order to improve, i.e., significantly increase, the service life or lifespan of such medical implants.

[0014] The solution to the problem underlying the invention is specified in claim 1. Features that advantageously develop the inventive concept are specified in the dependent claims.

[0015] According to the solution, the medical implant is characterized by the features of the preamble of claim 1 such that the foil-like, ribbon-shaped surface substrate of the electrical conductor arrangement is fluid-tightly surrounded by an elastic sheathing, at least in the longitudinal section connected on one side to the connection structure, and at least a part of the connection structure.

[0016] The functional principle underlying the proposed medical implant utilizes the same or a comparable principle as that governing the deformability of an accordion bellows. Thus, when deformed around a surface normal attributable to the surface substrate of the electrical conductor arrangement, the lateral edge is stretched within the corrugated longitudinal section, while the opposite lateral edge is compressed. The corrugated shape imprinted on the longitudinal section of the foil-like surface substrate connected to the connecting structure imparts the necessary elastic deformability to both opposing lateral edges of the surface substrate, allowing them to stretch or lengthen and compress or shorten accordingly, while avoiding or minimizing stress.significant reduction of shear forces that are harmful to the surface substrate.

[0017] It has proven advantageous to introduce a large number n > 2 of wave crests and wave troughs along the foil-like surface substrate, e.g., within the framework of a thermomechanical embossing process, into the surface substrate and to spatially form the wave shape by means of an elastic coating produced by means of potting, the respective assignable amplitude of which is either constant over the entire longitudinal section connected with the connecting structure, decreases continuously with increasing distance to the connecting structure, or decreases section by section or stepwise with increasing distance to the connecting structure.

[0018] The elastic sheathing, which fluid-tightly surrounds the film-like substrate in the longitudinal section connected to the bonding structure on one side and additionally encloses at least part of the bonding structure, preferably consists of an elastomer produced by a casting process. Silicone is particularly suitable as an elastomer, which, in addition to alternative elastomers, has a modulus of elasticity equal to or less than that of the film-like substrate, which is preferably made of polyimide.

[0019] The elastic coating, which forms as a solidified casting compound, surrounds the wave-shaped surface substrate including the connection structure, preferably in a tubular shape or in the form of an elongated ellipsoid.

[0020] Since the film-like, ribbon-shaped surface substrate has a substrate thickness of a few pm or a few tens of pm and a typical geometric length, extending between the cuff electrode arrangement and the connection structure (see Figure 4), of 1 to 3 cm, as well as a bandwidth of 1–2 mm, the fragility of this electrical conductor arrangement becomes apparent. To prevent movement-induced cracks in the surface substrate, particularly directly at the connection point between the connection structure (typically designed as a rigid ceramic plate) and the film-like, ribbon-shaped surface substrate, both the entire connection structure and the corrugated longitudinal section of the film-like, ribbon-shaped surface substrate, which is directly connected to the connection structure on one side and is also integrally and fluid-tightly encased by the elastic sheath, provide robust protection.This arrangement ensures that the substrate is not subjected to any significant, crack-inducing torsions or longitudinal elongations in this area. Another area of ​​the substrate that is critical for potential movement-related mechanical damage is the end of the elastic sheath opposite the connection structure, from which the otherwise unstructured, flat, film-like, ribbon-shaped substrate emerges and extends further towards the cuff electrode arrangement.Without further precautions, the film-like, ribbon-shaped surface substrate emerging from the elastic covering would be mechanically clamped on one side at this point, so that while deformations oriented orthogonally to the surface substrate plane would leave the surface substrate undamaged due to its surface flexibility, deformation forces acting on the film-like, ribbon-shaped surface substrate around the surface orthogonal could lead to damage, especially since the surface substrate is connected to the covering on one side via a linear clamping, similar to a clamping situation between two clamping jaws, or emerges from it.

[0021] To avoid or significantly reduce this mechanical stress, the cladding features a tapered extension extending towards the unstructured, film-like, ribbon-shaped substrate adjacent to the longitudinal section. This extension is monolithically connected to the cladding and encloses a portion of the unstructured, film-like, ribbon-shaped substrate. Its shape and dimensions give it greater, i.e., easier, deformability than the rest of the cladding. In this way, mechanical stresses that would otherwise lead to shear forces within the film-like, ribbon-shaped substrate are largely absorbed by the elastic extension of the cladding, while still ensuring a high degree of elasticity in this area.

[0022] It has also proven particularly advantageous that the sheathing has a rotationally symmetrical area facing the extension, which tapers conically towards the extension and preferably transitions continuously into the shape of the extension. Furthermore, it has proven advantageous to shape the extension in the manner of a duck's bill, with a width oriented transversely to the longitudinal extent of the electrical conductor arrangement and a thickness oriented orthogonally to the film-like, ribbon-shaped substrate, wherein the width and / or the thickness of the extension preferably decrease towards the end of the extension, from which the film-like, ribbon-shaped substrate emerges.

[0023] A further measure, supplementing the elastic covering described above, to avoid or significantly reduce movement-related mechanical damage to the film-like, ribbon-shaped surface substrate, which is bounded by two longitudinally extending and transversely opposing side edges, provides for both side edges to be designed in a meandering shape, at least in the longitudinal section of the electrical conductor arrangement that is connected to the connecting structure on one side and is surrounded by the elastic covering.

[0024] The term "meandering" refers to a sequence of successive geometric indentations and protrusions along both edges of the film-like substrate, relative to a virtual center line oriented along the longitudinal axis of the substrate. To prevent deformation-induced mechanical stress concentrations, the sequence of indentations and protrusions along the meandering edges is preferably characterized by a contour line consisting exclusively of rounded contours or of rounded contour lines connected by straight contour line segments.

[0025] The meandering shape of the side edges significantly increases the deformability and flexibility of the film-like substrate used in the electrical conductor assembly compared to a standard ribbon substrate with straight, parallel side edges. Particularly when the substrate deforms perpendicular to its center line or longitudinal axis, the resulting material expansion and contraction at the side edges is distributed and transmitted much more effectively within the material than in the case of straight side edges.

[0026] Inspired by the plant world, primarily by the geometric arrangement of individual leaves along the stem of a fern, which is characterized by high flexibility and deformability without sustaining damage, and in which the leaves are connected to the stem in a serial sequence with opposite extensions relative to the stem (i.e., no two leaves are ever axially aligned), a particularly preferred design for the solution-oriented meandering shape of the lateral edges of the foil-like substrate is such that the indentations along one edge of each of the two lateral edges are opposite or coincide with the indentations on the other edge of each of the two lateral edges in projection perpendicular to the midline. Analogous to the example from the plant world, each indentation would correspond to a leaf, i.e.,The protrusions arranged along the longitudinal extension of the foil-like surface substrate on both side edges are always axially offset from each other.

[0027] It has also proven advantageous to lay or arrange the electrical conductors on and / or in the substrate in a meandering longitudinal pattern, preferably with the proviso that the electrical conductors are positioned at a maximum distance transverse to the longitudinal extent of the substrate from both meandering side edges. In the case of the alternating axial arrangement of the protrusions along both side edges described above, the protrusions corresponding to the meandering shape of the electrical conductors follow the protrusions along both side edges.

[0028] In principle, the shape and size of the indentations and protrusions along both edges can be freely chosen, provided that mathematically inconsistent kinks are avoided along both edges. It has proven particularly advantageous to design and arrange the edges with the same or identical shape and size, but axially offset from each other. In the case of a sinusoidal edge design, the sine curves of both edges would run axially relative to each other without any phase shift.

[0029] To stay within the metaphor of sinusoidal side edge formation, but without limiting ourselves to the sinusoidal shape, it is advantageous that the amplitude attributable to the sinusoidally or meanderingly formed side edges decreases continuously or stepwise at least along a longitudinal section of the conductor arrangement with increasing distance to the connection structure.

[0030] In addition to the meandering shape of both side edges of the substrate, at least in the longitudinal section connected on one side by the connecting structure, a further embodiment provides a greater substrate thickness near the edges along the meandering side edges than in the rest of the substrate area. Alternatively to or in combination with the increased substrate thickness near the edges, it is also possible to round off at least some sections of the meandering side edges and / or to surround them with an edge protection material.

[0031] In most cases, the film-like substrate of the electrical conductor assembly is firmly joined to the connection structure by means of an adhesive or form-fit connection. From the perspective of the flexible electrical conductor assembly, this joining process is mechanically comparable to a cable clamped at one end, except that it involves a substantially two-dimensional, non-elastic band clamped at one end.

[0032] In addition to a variety of different configurations for the signal-applying and / or sensory-detection arrangement, a particular focus of the solution lies in the application with an electrode arrangement designed as a cuff, or cuff electrode arrangement for short, which is suitable for extravascular or extraneuronal fixation along an intracorporeal vessel or nerve fiber bundle, see Figure 4 and the preceding description. Brief description of the invention

[0033] The invention is described below by way of example, without limiting the general concept of the invention, with reference to the drawings. The drawings show:

[0034] Fig. 1 ae Side views of a detail section of a medical implant with a wavy, foil-like, ribbon-shaped surface substrate and elastic sheathing,

[0035] Fig. 2a, b Top and side view of a preferredly designed casing,

[0036] Fig. 3 Illustration of the functioning of a corrugated, foil-like surface substrate with sheathing,

[0037] Fig. 4 state-of-the-art medical implant as well as

[0038] Fig. 5 ae Detail sections of variants of a medical implant with wavy-shaped, foil-like, ribbon-shaped surface substrate and meandering side edge formation and elastic covering.

[0039] Ways to implement the invention, industrial applicability

[0040] Figure 1a shows a side view of the foil-like surface substrate 4 of the electrical conductor arrangement 8, which is connected on one side to the connection structure 5. Neither the signal-applying and / or sensor-detecting arrangement 1, as described in Figure 4 as a prior art representation and which would otherwise be connected to the surface substrate 4 on the left side in Figure 1a, nor the flexible cable 6 connected to a power supply unit 7, which is otherwise attached to the connection structure 5 on the right side, are shown. This also applies to Figures 1b to 1e.In order to give the foil-like surface substrate 4 at least within the longitudinal section 11 connected to the connecting structure 5 a kind of surface elasticity, a wavy shape structure 16 is imprinted into the surface substrate 4, which is characterized by a sequence of wave crests 19 and wave troughs 18 that extend orthogonally to an otherwise unstructured surface of the foil-like surface substrate 4.

[0041] Furthermore, an elastic sheath 17, preferably made of an elastomer, e.g. silicone, surrounds the connection structure 5 and the longitudinal section 11, along which the film-like, ribbon-shaped surface substrate 4 has the corrugated form structure 16, in a matrix-like manner. The elastomeric sheath 17 is preferably ellipsoidal in shape.

[0042] The elastomeric coating 17 in all its illustrated embodiments contributes to reducing the mechanical stress on the film-like surface substrate 4 and the wavy shape structure 16 imprinted therein, which results from the body's own movement-related deformation forces, and furthermore to creating a barrier to the moist body environment that is as fluid-tight as possible.

[0043] The surface elasticity conferred on the surface substrate 4 by the corrugated shape structure 16 is explained in more detail in Figure 3. Figure 3 shows a top view of the ribbon-shaped, film-like surface substrate 4, which is connected on one side to the connecting structure 5. Two deformation states, I and II, are shown: a first deformation state i, in which the film-like surface substrate 4 is deformed counterclockwise about its surface normal, and a second deformation state n, shown in the dashed line, in which the film-like surface substrate 4 is deformed clockwise about its surface normal. For clarity, the depiction of the sheathing 17 has been omitted in deformation state II.

[0044] In deformation state I, the upper side edge 20 undergoes stretching due to the elongation D acting there, and the lower side edge 21 undergoes compression due to the compression S acting there, which manifests itself on the one hand as a flattening and on the other hand as an increase in the waviness in the corrugated shape structure 16. In deformation state II, compression and stretching alternate sides, as can be seen in Figure 3.

[0045] Without the provision of the solution-specific wavy shape structure 16, material fatigue cracks form within the surface substrate 4 due to a constantly occurring change in load, which can be avoided or significantly reduced by the geometrically induced wavy shape of the surface substrate 4 within the longitudinal section 11 and the resulting inherent deformability of the surface substrate 4.

[0046] Figure 1b, in contrast to Figure 1a, where the wave crests 19 and wave troughs 18 are constant in shape and size, i.e. frequency and amplitude, over the entire extent of the longitudinal section 11, shows an embodiment in which the amplitudes, i.e. the size, of the wave crests 19 and wave troughs 18 are of the same dimension, but in a first section 22, which is connected to the connecting structure 5, the periodicity, i.e. the frequency of the wave crests 19 and wave troughs 18, is greater than in the second section 23.

[0047] Figure 1c shows an alternative embodiment in which the periodicity, i.e. the frequency of the sequence of wave crests 19 and wave troughs 18, is constant, but in a first section 22, which is connected to the connecting structure 5, the amplitude of the wave crests 19 and wave troughs 18 is greater than in the second section 23.

[0048] Figure 1d shows another alternative embodiment in which the amplitude of the wave crests 19 and wave troughs 18 decreases continuously with increasing distance to the connecting structure 5.

[0049] In Figure 1e, a tapered extension 24 of the encasing 17 is provided on the ellipsoidally shaped sheathing 17 in the direction of the unstructured, film-like surface substrate 4. This extension is monolithically connected to the sheathing 17 and, due to its shape and dimensions, exhibits greater, i.e., easier, deformability compared to the sheathing. Figure 2a shows a top view, and Figure 2b a side view, of a particularly advantageous embodiment of an elastic sheathing 17. This sheathing completely surrounds the longitudinal section 11 of the corrugated surface substrate 4 as well as the connecting structure 5, thus forming a monolithic elastic matrix composite. Electrical conductors 3 are embedded along the length of the film-like, ribbon-shaped surface substrate 4 and are connected to a cuff electrode arrangement (not shown).The electrical conductors 3 contact a multi-pole extension cable 6 on the connection structure 5, which leads to a supply unit not shown.

[0050] Of particular importance is the shape of the casing 17 in the area of ​​the extension 24, where the wavy shape structure 16 of the film-like, ribbon-shaped surface substrate 4 flattens to the left (see Fig. 2b) and emerges from the casing 17 in a straight line. In the area where the amplitude of the wavy shape structure 16 begins to flatten to the left, the casing 17 has a rotationally symmetric, conically tapered outer contour 26, which transitions continuously into the duckbill-shaped extension 24, from which the unstructured, i.e., flat, film-like, ribbon-shaped surface substrate 4 emerges.The duckbill-shaped extension 24 has a width B oriented transversely to the longitudinal extent of the electrical conductor arrangement 8 and a thickness D oriented orthogonally to the foil-like, band-shaped surface substrate 4, wherein the width B and the thickness D of the extension 24 decrease in the direction of the extension end 25, from which the foil-like, band-shaped surface substrate 4 emerges.The width B and thickness D are geometrically adapted to the shape and size of the film-like, ribbon-shaped surface substrate 4 such that the extension 24 surrounds the film-like, ribbon-shaped surface substrate 4 flush and fluid-tight, and is flexible in comparison to the film-like, ribbon-shaped surface substrate 4 in such a way that at the extension end 25, where the film-like, ribbon-shaped surface substrate 4 exits the extension 24, the film-like, ribbon-shaped surface substrate 4 dictates the movements and not the extension 24. In this way, buckling of the film-like, ribbon-shaped surface substrate 4 at the end 25 of the highly flexible extension 24 is prevented.

[0051] Turning away from the end 25 of the extension 24, the duckbill-shaped extension 24 transitions continuously into a sheath 17 with a conically widening, rotationally symmetric outer contour 26. Torsional forces acting on the film-like, ribbon-shaped substrate 4 can thus be ideally transferred via the highly flexible extension 24 into the region 26 of the rotationally symmetric cone shape, where the torsional forces are effectively dampened by the combination of the flexible sheath 17, preferably made of silicone, and the increasing diameter. Preferably, the corrugated shape structure 16, or at least the largest portion of the shape structure 16, is arranged in precisely this region of the sheath 17.

[0052] A further measure, supplementing the elastic covering 17 described above, to prevent or significantly reduce movement-induced mechanical damage to the film-like, ribbon-shaped surface substrate 4, which is bounded by two longitudinally extending and transversely opposing side edges 9, 10, provides for both side edges 9, 10 to be designed in a meandering shape, at least in the longitudinal section 11 of the electrical conductor arrangement 8, which is connected on one side to the connecting structure 5 and is surrounded by the elastic covering 17. Variants of this design are illustrated in Figures 5a to 5e. The covering 17 shown in a highly schematic form in Figures 5a to 5e is to be understood as representative of all embodiments described above, i.e.,Furthermore, and in particular, the coverings 17 indicated graphically in Figures 5a to 5e are each to be designed in the manner of a covering 17 illustrated in Figure 2. Figure 5a shows such a design of a medical implant with an electrical conductor arrangement 8 extending longitudinally, which has a film-like surface substrate 4 made of a flexible and non-elastic material, on and / or in which a number of electrical conductors 3 are arranged, and along its longitudinal extent the electrical conductor arrangement 8 is mechanically and electrically connected, and movably relative to, a signal-applying and / or sensor-detecting arrangement 1' on the one hand and to a rigid connection structure 5 on the other.The signal-applying and / or sensor-detecting arrangement 1' is, for example, a cuff electrode assembly 1, as already explained with reference to Figure 4. However, any medically active implant can also be considered, for whose signal and energy supply an electrical connection to a supply unit 7 located away from the site of the active implant is required.

[0053] The film-like surface substrate 4 of the electrical conductor arrangement 8 is bounded by two longitudinally extending and transversely opposing side edges 9, 10, which are meanderingly structured at least in a longitudinal section 11 of the electrical conductor arrangement 8 that is connected on one side to the connecting structure 5. In Figure 5a, the meandering side edge region 12 of both side edges 9, 10 is highlighted with hatching. In principle, the meandering side edge region 12 can extend over the entire length of both side edges 9, 10. Furthermore, the foil-like, ribbon-shaped surface substrate 4, together with the electrical conductors 3 arranged therein or on it, is wavy along the meandering longitudinal section 11, i.e. the wavy shape structure 16 extends orthogonally to the surface of the foil-like surface substrate 4, as shown in Figure 5e.The wavy shape structure 16 embossed within the longitudinal section 11 in the film-like, ribbon-shaped surface substrate 4 is realized in all embodiments relating to Figures 5a to 5e. Figure 5b shows a specific embodiment for a meandering shape of the side edges 9, 10 within the longitudinal sections 11 of the electrical conductor arrangement 8, which are connected on one side to the connecting structure 5.

[0054] The meandering side edge regions 12 of both side edges 9, 10 are each characterized by a sequence of longitudinally successive indentations 14 and protrusions 15 oriented relative to a virtual center line 13 running lengthwise along the side edges 9, 10. In the case of Figure 5b, the indentations and protrusions 14, 15 are arranged symmetrically opposite each other along both side edges 9, 10 with respect to the center line 13. One criterion for the design of the meandering shape is to avoid kinks and to connect the round indentations and protrusions 14, 15, whatever their shape and size, by round or straight contours. In this case, as in the prior art (see Figure 4), the electrical conductors 3 run parallel to the center line 13.

[0055] Particularly pronounced resistance to movement-induced cracking within the film-like surface substrate 4 of the electrical conductor arrangement 8 can be achieved by designing the meandering side edge regions 12 in such a way that the indentations 14 along one side edge 9 coincide with the protrusions 15 of the other side edge 10, or in such a way that the indentations 14 along the other side edge 10 coincide with the protrusions 15 of one side edge 9 in projection perpendicular to the center line 13, as can be seen in Figure 5c. In this case, it is also advantageous to arrange the electrical conductors 3 in a meandering pattern along the film-like, ribbon-shaped surface substrate 4 in order to create a maximum lateral distance to both meandering side edge regions 12 of both side edges 9, 10.

[0056] The indentations and protrusions 14, 15 do not necessarily have to be uniform and of constant size. Figure 5d shows an electrical conductor arrangement 8 with meandering longitudinal sections 11, along which the amplitudes of the indentations and protrusions 14, 15 decrease with increasing distance from the connecting structure 5. The electrical conductors 3 are also laid or arranged in the same meandering shape on the foil-like, ribbon-shaped surface substrate 4. The change in shape and / or size of the indentations and protrusions 14, 15 can, as in the case of Figure 5d, occur continuously depending on the distance to the connecting structure 5, or stepwise, i.e., in intervals of distance to the connecting structure 5.

[0057] Figure 5e shows a schematic side view of the electrical conductor arrangement 8 connected to the connecting structure 5, which applies accordingly to all meandering, foil-like, ribbon-shaped surface substrates 4 shown in Figures 5a to 5d. The foil-like, ribbon-shaped surface substrate 4, together with the electrical conductors 3 arranged therein or on it, is wavy at least along the meandering longitudinal sections 11, i.e., the wavy shape structure 16 extends orthogonally to the surface of the foil-like surface substrate 4, so that the foil-like surface substrate 4 undergoes elongation by way of elastic tensile deformation when tensile forces act along the electrical conductor arrangement 3, thus effectively reducing the effect of the tensile force.

[0058] Reference symbol

[0059] Cuff electrode arrangement ' signal-applying and / or sensor-detecting arrangement'

[0060] Nerve fiber bundles, vagus nerve, electrical conductors, foil-like, band-shaped surface substrate

[0061] Flexible cable connection structure

[0062] Supply unit electrical conductor arrangement, 10 side edges of the electrical conductor arrangement 1 longitudinal section 2 meandering side edge area, 3 center line 4 indentation 5 bulge 6 wavy shape structure 7 sheathing 8 wave trough 9 wave crest 0 upper side edge 1 lower side edge 2 first section 3 second section 4 extension 25 end

[0063] 26 Rotationally symmetrical area with conical outer contour

Claims

Patent claims 1. Medical implant with an electrical conduction arrangement (8) extending over a longitudinal extent, comprising a film-like, ribbon-shaped surface substrate (4) made of a flexible and non-elastic material, on and / or in which a number of electrical conductors (3) are arranged, and along its longitudinal extent the electrical conduction arrangement (8) is mechanically and electrically connected, and relative to it, on the one hand to a signal-applying and / or sensor-detecting arrangement (T) and, on the other hand, opposite this arrangement in its longitudinal extent, to a rigid connecting structure (5), wherein the film-like, ribbon-shaped surface substrate (4) of the electrical conduction arrangement (8) has, at least in a longitudinal section connected to the connecting structure (5) on one side, a wavy shape structure (16) characterized by a sequence of at least one wave crest and one wave trough,which extend orthogonally to an otherwise flat surface of the film-like, ribbon-shaped surface substrate (4), characterized in that the film-like, ribbon-shaped surface substrate (4) of the electrical conduction arrangement (8) is fluid-tightly surrounded by an elastic sheathing (17) at least in the longitudinal section connected on one side to the connection structure (5) and at least a part of the connection structure.

2. Medical implant according to claim 1, characterized in that the corrugated shape structure (16) has a plurality n > 2 of wave crests and wave troughs, each of which can be assigned an amplitude that a) is constant over the longitudinal section, b) decreases continuously with increasing distance to the connecting structure (5), or c) decreases section by section with increasing distance to the connecting structure (5).

3. Medical implant according to claim 1 or 2, characterized in that the elastic covering (17) has an E-modulus which is equal to or less than an E-modulus attributable to the foil-like, ribbon-shaped surface substrate (4).

4. Medical implant according to one of claims 1 to 3, characterized in that the elastic coating consists of silicone.

5. Medical implant according to one of claims 1 to 4, characterized in that the elastic covering is tubular or ellipsoidal in shape.

6. Medical implant according to one of claims 1 to 5, characterized in that the wavy shape structure (16) is introduced into the foil-like, ribbon-shaped surface substrate (4) by thermomechanical embossing.

7. Medical implant according to one of claims 1 to 6, characterized in that the wavy shape structure (16) can be produced by elastically forming the foil-like, ribbon-shaped surface substrate (4) and casting around the wavy shape structure (16) to form the elastic covering.

8. Medical implant according to one of claims 1 to 7, characterized in that the covering (17) has the wavy shape structure (16) over the entire length of the longitudinal section (11) and completely encloses the supply structure (5).

9. Medical implant according to claim 8, characterized in that, in the direction of the unstructured, film-like, band-shaped surface substrate (4) adjoining the longitudinal section (11), the covering provides a tapered extension (24) which is monolithically connected to the covering (17) and encloses a part of the unstructured, film-like, band-shaped surface substrate (4), and that, due to its shape and dimensions, the extension (24) has a higher, i.e., easier deformability than the rest of the covering (17).

10. Medical implant according to claim 9, characterized in that the covering (17) has a rotationally symmetrical area (26) facing the extension (24), which tapers conically in the direction of the extension (25).

11. Medical implant according to claim 9 or 10, characterized in that the extension (24) has a duckbill-like shape, with a width (B) oriented transversely to the longitudinal extent of the electrical conductor arrangement (8) and a thickness (D) oriented orthogonally to the foil-like, band-shaped surface substrate (4), and that the width (B) and / or the thickness (D) of the extension (24) decrease in the direction of an end (25) associated with the extension (24), from which the foil-like, band-shaped surface substrate (4) emerges.

12. Medical implant according to claims 10 and 11, characterized in that the rotationally symmetrical conical area (26) of the covering (17) transitions continuously into the shape of the extension (24).

13. Medical implant according to one of claims 1 to 12, characterized in that the film-like surface substrate (4) is bounded by two longitudinally extending side edges (9, 10) that are opposite each other transversely to the longitudinal extension, and that both side edges (9, 10) are meander-shaped at least in the longitudinal section of the electrical conductor arrangement (8) which is connected on one side to the connecting structure (5).

14. Medical implant according to claim 13, characterized in that the meandering side edges (9, 10) are each characterized by a sequence of indentations and protrusions (14, 15) in the longitudinal extension and relative to a longitudinally oriented virtual center line (13) such that the indentations (14) along one side edge (9) of the two side edges (9, 10) coincide with the protrusions (15) of the other side edge (10) of the two side edges (9, 10) in projection transverse to the center line (13).

15. Medical implant according to claim 13 or 14, characterized in that the indentations and protrusions (14, 15) of both side edges (9, 10) are identical in shape and size.

16. Medical implant according to claim 13 or 14, characterized in that an amplitude attributable to the meandering side edges (9, 10) is at least along a longitudinal section (11 ) the line arrangement (8) decreases continuously or stepwise with increasing distance to the connection structure (5).

17. Medical implant according to one of claims 13 to 15, characterized in that the number of electrical conductors (3) is arranged in a meandering longitudinal direction on and / or in the surface substrate (4).

18. Medical implant according to claim 17, characterized in that the electrical conductors (3) are each arranged under the maxim of a maximum distance transverse to the longitudinal extent to both meander-shaped side edges (9, 10).

19. Medical implant according to one of claims 13 to 18, characterized in that the meandering side edges (9, 10) are formed at least section by section with a greater surface substrate thickness than in the remaining surface substrate area.

20. Medical implant according to one of claims 13 to 19, characterized in that the meandering side edges (9, 10) are at least partially rounded and / or surrounded with an edge protection material.

21. Medical implant according to one of claims 13 to 20, characterized in that the sequence of indentations and protrusions (14, 15) along the meandering side edges (9, 10) is each characterized exclusively by a contour line with round contour line shapes or with round contour line shapes connected by straight contour line sections.

22. Medical implant according to one of claims 1 to 21, characterized in that the signal-applying and / or sensor-detecting arrangement (1') is an electrode arrangement designed as a cuff, or cuff electrode arrangement (1), which is suitable for extravascular or extraneuronal attachment along an intracorporeal vessel or nerve fiber bundle (2), and that the rigid connecting structure (5) is electrically connected by wire to an implantable supply unit (7) separately designed for the cuff electrode arrangement (1).

23. Medical implant according to claim 22, characterized in that the cuff electrode arrangement (1 ) is made of a foil-like surface substrate (4) which is monolithically connected to the surface substrate (4) of the electrical conductor arrangement (8) having a longitudinal extension.

24. Medical implant according to one of claims 1 to 23, characterized in that the surface substrate (4) consists of a polymer, preferably polyimide (PI).

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