Patent Application
20200246609
The invention relates to an implantable electrical, connecting structure between an electrical implant, which has at least one electrical conductor, and an electric feed and drain line structure.
Electronic implants, which are suitable for permanent, or at least long-term, retention in the body, are typically used to influence organ functions therapeutically. Examples of known art are cardiac or brain pacemakers. Depending on the application purpose and complexity of the therapeutic objective, generic implants have a multiplicity of electrical feed and drain lines, which supply the implant in question with electrical control and regulatory signals, together with electrical power. The number of electrical feed and drain lines for electronically complex implants may well include twenty or more electrical lines assembled into a flexible cable, by means of which the implant is connected to a control unit, which is usually combined with a power source. The intra-corporeal positioning of the control unit and the power source is usually performed subcutaneously in a part of the body, such as the chest region, or near the clavicle, where the external and internal stresses caused by movement are as small as possible for the person, and ease of surgical access is possible.
As a rule, the electrical feed and drain lines between the implant and the control unit and/or power source are not integrally designed, but are implemented via at least one interface in the form of an intra-corporeal plug connection, or a detachable or non-detachable electrical connection, for example in the form of a bonded or soldered connection. On the one hand, this raises problems related to the installation space required for the interface, and on the other hand it is necessary to make the interface region moisture-resistant, on account of the moist intra-corporeal environment.
Using the example of an implantable cuff electrode arrangement to be supplied via a multi-pole feed and drain line structure, the problems existing up to the present time concerning an implantable electrical multi-pole connecting structure known per se will be explained in more detail with reference to the illustrations to be found in
For the purpose of making electrical contact with the microflex structures 5, a ceramic adapter plate 6 is used in a manner known per se, on which, in accordance with the number and arrangement of the microflex structures 5, so-called microflex contacts or microflex pads 7 are attached; these are brought into contact with the microflex structures 5, and are in each case connected individually in an electrically conductive manner to the electrode surfaces 8 mounted on the surface of the ceramic adapter plate 6. Individual electric wires 10 of an electrical feed and drain line structure 11 are connected to the individual electrode surfaces 8, designed as solder pads, via soldered or bonded connections 9.
In order to improve the electrical as well as the mechanical contact between an electrical feed and drain line 3 and the electrical conductor structure 12 mounted on the ceramic adapter plate, two, three or a plurality of such microflex contacts 13 can be provided side-by-side along the electrical feed and drain line 3 running within the support substrate 4, in a manner known per se.
Needless to say, the entire electrical connection arrangement shown in
It is obvious that the installation space required for the electrical connecting structure of known art increases with increasing complexity and multi-polarity of the unit to be implanted, as a result of which the loading on, and irritation to, the patient also increases in the same manner.
An implantable thin-film electrode arrangement, which has a uniform thin-film surface substrate, which has a first section that can be deformed into a winding electrode, a second section for making electrical contact with an electric feed and drain line structure, and a third section connecting the two sections with one another, can be found in U.S. Pat. No. 5,324,322. In this patent nothing is presented concerning the configuration of the contact ends in terms of the electrical feed and drain line structure.
The invention is an implantable electrical connecting structure between an electrical implant, which has at least one electrical conductor, and an electrical feed and drain line structure, such that the loading on the patient is to be significantly reduced, compared to generic connecting structures of known art. In particular, a connecting structure is to be created that is as flexible as possible, in order to ensure a high degree of reliability with regard to a durable electrical connection.
The implantable electrical connecting structure of the invention is between an electrical implant, which has at least one electrical conductor, and an electrical feed and drain line structure, in which the electrical feed and drain line structure comprises at least one electric cable with a cable end to which an electrically conductive flat piece is attached in an unsupported manner, to which flat piece the at least one implant-side electrical conductor is directly joined.
The connecting structure of the invention thus avoids the rigid and planar ceramic adapter plate, and opens up the possibility of a highly flexible configuration of the implantable electrical connecting structure of a miniaturizable design, by which a patient-specific loading associated with the implantation can be significantly reduced.
The invention is based on the connecting the end of an implant-side electrical conductor directly to the cable end of a cable, which is part of an electrical feed and drain line structure, and, for example, is connected to an electrical energy and/or control module, in a directly electrically conductive manner. The electrical connection is robust and mechanically loadable, such that it can withstand compressive and tensile forces that can result from elastic or plastic deformations of the cable section immediately adjacent to the connection, or of the implant-side electrical conductor. In order to achieve the high degree of flexibility, the flat piece attached to the cable end is unsupported without any kind of mechanical support, and defines the electrical and mechanical connection region between an implant-side electrical conductor and a cable.
The flat piece, preferably consisting of the same metallic material as the cable itself, can be in the form of a separate component that is permanently attached to the cable end by a joint, for example by soldering, welding, adhesive or mechanical clamping.
The size and shape of the flat piece, which is preferably designed as a metallic platelet, has been selected in the interests of a design of the implantable electric connecting structure being miniaturized as far as possible, exclusively for the purpose of providing a mechanically strong and electrically conductive connection between one cable end of the electrical feed and drain line structure and one implant-side electrical conductor, having surface sizes measuring in the range of only a few μm2.
At the same time, it is appropriate to form the flat piece by material forming the cable material at the cable end so that the flat piece is integrally connected to the respective cable.
The support substrate, having a flexible, film-like, electrically non-conductive surface element, confers to the multiplicity of electrical conductors embedded in the film-like surface element both a defined relative arrangement to one another, and also a mechanical hold for their handling as a whole. In a particularly preferred form of embodiment, the film-like support substrate has finger-like film end sections for the purpose of making electrical contact with the individual electrical conductors in an edge-side film region, along each of which at least one electrical conductor is embedded. In each of the finger-like film end sections at least one opening is provided, which passes through the film together with the at least one electrical conductor and within which the at least one electrical conductor has a freely accessible conductor surface, which is electrically and mechanically robustly connected to a flat piece of a cable by a welded, adhesively bonded, wire bonded, ball bonded or soldered connection.
The joining of a flat piece attached to one cable end to the exposed electrical conductor ends in the finger-like film end sections requires only a mutual spatial overlapping and joining, preferably by forming a local microflex contact. In order to improve the electrical and mechanical contact between an electrical conductor and a flat piece, microflex contacts can be provided along one conductor end.
By virtue of the spatially separated formation of the electrical contacts between the cables and the electrical conductors, that is preferably only one cable leads to each finger-like film end section. The cables can be arranged spatially independently of one another, for example in order to bring them together to form the slimmest possible cable loom, and the finger-like film end sections can also be wound or rolled together, in the context of film flexibility, to form the most compact and space-saving film geometry possible.
The implantable electric connecting structure of the invention can be produced in a particularly advantageous way. Thus, first of all it is necessary to provide at least one cable belonging to the electrical feed and drain line structure, with an electrically conductive flat piece attached to the cable end. Such a pre-assembled cable can be provided either by joining a separate metallic flat piece to a cable end, or by mechanically deforming a cable end to form a flat piece integrally connected to the cable end.
In addition, the flat piece attached to the cable end is joined to a freely accessible end section of an implant-side electrical conductor. The handling of the cable and the electrical conductor during the joining process, in which a welding, adhesive bonding, wire bonding, ball bonding or soldering technique is preferably used, is simplified by the mechanically stable connection of the at least one electrical conductor within the flexible, film-like, electrically non-conductive surface element, which is positioned in a fixed manner on a base. Thus, it is only necessary to position the cable-side flat piece at the location of the exposed conductor end section, preferably between the support and the flat piece. For example, by applying a gold ball bond in the region of the finger-like film end sections together with openings through the electrical conductor end sections, a stable microflex contact is created.
The drawings illustrate a preferred form of embodiment of an implantable electric connecting structure designed according to the invention. Finally, a polymeric encapsulation material is preferably applied around the electrical connecting structure to protect the electrical connection from the aqueous environment of the body.
The invention is described below in an exemplary manner by way of examples of embodiment with reference to the drawings, without any limitation of the general inventive concept. Here:
a, b, c show an implantable connecting structure known per se in accordance with the prior art.
The electrical conductors 3 provided on the implant side are usually integrated in a support substrate 4 in the form of a flexible, film-like, electrically non-conductive surface element 4, preferably in the form of a biocompatible polymer film. In the example of embodiment shown, each individual electrical cable 3 leads along a finger-like film end section 4a. The number of individual film end sections 4a corresponds to the number of individual electrical lines 3 leading to the implant.
For purposes of making contact between the electrical lines 3 and an electrical supply cable 10, each cable 10 provides a metallic, platelet-shaped flat piece 16, which is either connected to the end of a cable 10 via a joint 17, for example by means of welding, adhesively bonding, wire bonding or a soldered joint, or is integrally formed from the cable end by material deformation. See also the longitudinal section representation in
Each of the finger-like film end sections 4a has two openings 14 to form two microflex contacts 13, which pass through both the film end section 4a and the electrical conductor 3 locally. Each individual film end section 4a rests directly on one side of a surface of the flat piece 16, having a thickness which can range from some 10 g of μm to some 100 g of μm. To provide joints that are electrically and mechanically sound, the two openings 14 within each individual film end section 4a are filled with a ball bond 15, which preferably a gold bond.
If necessary, only one microflex contact 13, or multiple microflex contacts 13, can be provided along an electrical conductor 3, depending on the anticipated loading situation that the connecting structure has to withstand.
The shape and surface size of the individual flat pieces 16 must be selected with a view to being miniaturized and compact of a design as possible for each individual electrical connecting structure, and is primarily directed at the shape and size of the implant-side film end sections 4a.
Even with a large number of electrical conductors 3 and the cables 10 connected thereto, it is possible to transform the finger-like film end sections 4a into a small cylindrical design, by winding them, for example, around an axis oriented in the longitudinal extent of the film end sections 4a, from which the cables 10, in close proximity to one another, lead into the electrical feed and drain line structure 11. It is precisely this deformability of the design of the implantable electrical connecting structure that constitutes the particular advantage, by means of which miniaturization of the structure is made possible.
Other shapes and geometries can also be used for the configuration of the contact region of the film-like support substrate 4a. All connection techniques known in the art, and suitable for this particular application, such as friction welding, ultrasonic welding, soldering, gluing, bonding methods, etc., are also suitable for the configuration of the electrical and mechanical joint between the individual electrical conductors 3 and the flat pieces 16 of the cables 10.
In order to prevent the electrically conductive flat pieces 16 from forming electrical short circuits, they must be enclosed with an electrically insulating layer material or a potting compound before a space-saving sculpting of the connecting structure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 209 773.6 | Jun 2017 | DE | national |
Reference is made to PCT/EP2018/063863 filed May 28, 2018, designating the United States, which claims priority to German Application No. 10 2017 209 767.1 filed Jun. 9, 2017, which are incorporated herein by reference in their entirety
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/063864 | 5/28/2018 | WO | 00 |
