The invention relates to a device for the extravasal or extraneuronal fastening of a medical implant with a biocompatible surface substrate having a first substrate portion which is configured as a compression sleeve and has a free end portion, which by winding the first substrate portion about a spatial axis, is loosely radially covered in at least layer by the wound first substrate portion, and also second substrate portion, which is attached integrally to the first substrate portion, is not wound about the spatial axis, and is connectable directly or indirectly to a connection structure leading away from the medical implant.
A medical implant of this type, configured in the manner of a compression sleeve for detection as well as application of neuronal electrical signals for permanent or at least long-term positioning along a nerve fiber bundle within the human or animal body is described in WO 2016/055512 A1 and is also shown schematically in
Through material pre-tensioning applied to the surface substrate 2 in the first substrate portion 3, the surface substrate 2 takes on a predefined winding configuration without the effect of external forces, in which the free portion end 4 is at least loosely radially covered in one layer by the first substrate portion, that is by at least one surface substrate winding.
Adjoining the wound first substrate portion 3 in one piece, and not wound about the spatial axis 5 is a second substrate portion 6, within which there are electrical leads that are connected to the plurality of electrodes coming into contact with the epineurium of the nerve fiber bundle. In the illustrated example embodiment, the also flat second substrate portion 6 comprises a web-like surface portion 6 orientated in parallel to the spatial axis 5, which via an interface S, not illustrated, in the form of an implantable plug connection for example, is connected to a connection structure 7 leading away from the medical implant 1 along which the electrical leads extend to a separate, preferably implantable unit.
In an unstressed state, the mechanical implant 1 lies along a nerve fiber bundle N in accordance with the schematic view in
A cuff electrode in an original form is set out in DE 44 33 111 A1 and has an interdigital surface form, with individual finger portions opening outward depending on external pressure and force exertions.
U.S. Pat. No. 4,602,624 discloses an implantable cuff electrode with a surface substrate which winds itself into a hollow cylindrical shape and has different internal diameters in the axial longitudinal extension. The hollow cylindrical shape is solely maintained by inherent material predetermined pre-tensioning.
WO 2013/150524 A1 discloses an electrode cuff arrangement with a series of individual metal cuffs serving as electrodes, which are all radially encompassed from outside by a metal housing, which can be transformed from an open into a closed state in which the latter is secured by a locking clip mechanism.
The invention is a device for extravasal or extraneuronal fastening of a medical implant with a biocompatible surface substrate having a first substrate portion, which is configured as a compression sleeve and has a free end portion, which by winding the first substrate portion about a spatial axis, is loosely radially covered in at least a layer by the wound first substrate portion, and also has second substrate portion, which is attached integrally to the first substrate portion, is not wound about the spatial axis, and is connectable directly or indirectly to a connection structure leading away from the medical implant. Thus a secure and at the same time protected and durable application of the medical implant along an intracorporeal vessel or nerve fiber bundle is obtained. The measures to be taken should avoid movement-related deformations of the compression sleeve, or at least reduce them to such a degree that no appreciable mechanical stresses are exerted on the intracorporeal vessel of nerve fiber bundle. For the operator, the measures to be taken should not represent appreciable additional effort in terms of time or manipulation during the implantation.
In accordance with the invention, a device for the extravasal or extraneuronal fastening of a medical implant with a biocompatible surface substrate having a first substrate portion, configured as a compression sleeve, is characterised in the region of the end portion of the first substate portion configured as a compression sleeve, has at least one attachment applied thereto, which in the wound state of the first substrate portion about the spatial axis forms a joint connection with at least one of the first substrate portion and the second substrate portion being spatially separated from the portion end.
According to the invention, the end at the free portion of the first substrate portion which is configured as a compression sleeve, is detachably firmly connected which by the attachment to transmit at least one tensile force to an area of the carrier substrate which is preferably located within the second substrate area, which is the area of the carrier substrate that integrally adjoins the first substrate portion of the compression sleeve. The at least one attachment is arranged and designed so that in the case of an external force acting on the medical implant, a stopping or supporting force is produced through which the form and shape of the compression sleeve remains unchanged. The at least one attachment can primarily transmit tensile force between the free portion end and the join area. In principle it is also possible to provide a joint connection area within the first substrate portion, but in this case it must be ensured that between the area of the portion end on which the attachment is applied, and the joint connection at least one complete winding of the first sustrate portion extends about the spatial axis.
In a preferred embodiment, the at least one attachment is a flexible and non-stretchable strand of material, preferably in the form of a thread or strip. In each case, the strand of material is firmly attached by its two ends in the region of the end of the first substate portion or is integrally connected thereto. The other end of the strand of material is fastened in the area of at least one of the first and second substrate portion by a detachable firm joint connection, preferably as at least one of a frictional and interlocking connection. Advantageously, for this, in the area of at least one of the first and second substrate portion the biocompatible surface substrate has at least one fastening opening, completely passing through the surface substrate, through which the strand of material can be threaded for the purpose of providing a detachable firm connection, preferably for forming a knot.
In a preferred embodiment, the at least one attachment is designed as a tab which laterally projects beyond the first substrate portion in the area of the end if the portion and is connected thereto in one piece. Provided along the first or second substrate portion is a slit-shaped recess into which the tab can be introduced, forming a frictional and/or interlocking joint connection. Here, preferably the slit-shaped recess is located within an area of the first or second substrate portion which projects beyond the first substrate portion configured as a compression sleeve in the longitudinal extension of the winding. A more detailed explanation of this is set out in the following description with reference to a concrete example of embodiment.
Fundamentally, the first substrate portion has a longitudinal winding extension orientated about the spatial axis as well as a longitudinal cuff extension orientated axially to the spatial axis, wherein the longitudinal winding extension is determined by the distance between the free end portion and the second substrate portion adjoining the first substrate portion. In a preferred embodiment, the longitudinal cuff extension tapers within the first substrate portion as the distance increases to the end of the portion in a stepwise manner, preferably evenly along the winding extension. Through this, the opposite ends of the portion end in the wound form of the first substrate portion axially remain freely accessible from outside, so that the strand of material can extent to the joint area without being hindered by each of the opposite ends of the portion end.
Other aspects and features in accordance with the invention are set out in the further description with reference to the drawings.
As an example, the invention will be described below, without restricting the general inventive concept, by way of examples of embodiment with reference to the drawings. Here:
Firmly fastened centrally along the free portion end 4 is one end of a strand of material 8, which preferably is a thread, strip or comparable attachment that transits tensile forces. The firm connection 10 is at least one of bonded/frictional and interlocking non-detachable connection. Starting from the place of connection 10, the strand of material 8 extends through openings 11 which are provided in the first substrate portion 3 and are shown being in wound state, with radially overlaps each other in a congruent manner. In this way the strand of material 8 traverses the compression sleeve from inside to outside. The end of the stand of material opposite the connection 10 is locally connected to the second substrate portion 6 in the form of a detachable firm joint connection 12. In the area of the joint connection 12, on the surface substrate 2, an opening 13 is provided through which the strand of material 8 passes and, preferably by means of knotting, is connected to the second substrate portion 6.
Through the central application along the longitudinal cuff extension L of the strand material 8 on portion end 4, tensile forces are symmetrically transferred to the portion end 4 with unrolling of the compression sleeve being prevented. In addition, through the symmetrical force transmission, asymmetrical stress conditions, as illustrated in
Instead of a single strand material, the embodiment illustrated in figure lb has two separate strand materials 8 which each are a surgical thread, which is unilaterally firmed fixed to the ends 41, 42 of the free portion end 4 of the first substrate portion 3. At the free ends 81, 82, both strands of material 8 are attached to the second substrate portion 6 via a detachably fixed joint connections 9. In this case also, the joint connections 9, are formed by each passing through the surface substrate 2 in the second substrate portion 6.
It is of course possible combine the measures described in the above examples of embodiment with each other.
Number | Date | Country | Kind |
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10 2018 207 709.6 | May 2018 | DE | national |
REFERENCE IS MADE TO PCT/EP2019/061599 FILED MAY 7, 2019, DESIGNATING THE UNITED STATES, WHICH CLAIMS PRIORITY TO GERMAN APPLICATION NO. 10 2018 207 709.6 FILED MAY 17, 2018, WHICH ARE INCORPORATED HEREIN BY REFERENCE IN THEIR ENTIRETY
Filing Document | Filing Date | Country | Kind |
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PCT/EP2019/061599 | 5/7/2019 | WO | 00 |