Implantable Electrode Lead with Conductors Connected to Form a Braid

Abstract

An implantable electrode lead comprises at least one electrode pole and a plurality of electrical conductors, at least one of which is electrically connected to the at least one electrode pole. The plurality of conductors are connected to one another to form a braid extending along a longitudinal axis, at least one first conductor of the plurality of conductors being helically wound about the longitudinal axis in a first direction of rotation, and at least one second conductor of the plurality of conductors being helically wound about the longitudinal axis in a second direction of rotation, which is opposite the first direction of rotation.

Claims

1. An implantable electrode lead, comprising, at least one electrode pole; and a plurality of electrical conductors, at least one of which is electrically connected to the at least one electrode pole, wherein the plurality of conductors are connected to one another to form a braid extending along a longitudinal axis, at least one first conductor of the plurality of conductors being helically wound about the longitudinal axis in a first direction of rotation, and at least one second conductor of the plurality of conductors being helically wound about the longitudinal axis in a second direction of rotation, which is opposite the first direction of rotation.

2. The implantable electrode lead according to claim 1, wherein the braid has a length, the plurality of conductors extending along the length of the braid.

3. The implantable electrode lead according to claim 1, wherein the plurality of conductors are arranged on an inner tube and are wound around the inner tube.

4. The implantable electrode lead according to claim 1, wherein the at least one first conductor is electrically connected to the at least one electrode pole at a first connection point and the at least one second conductor is electrically connected to the at least one first conductor at a second connection point.

5. The implantable electrode lead according to claim 1, wherein the at least one first conductor and/or the at least one second conductor has at least one interruption point at which the at least one first conductor and/or the at least one second conductor is electrically interrupted.

6. The implantable electrode lead according to claim 1, wherein the at least one electrode pole is annular and extends circumferentially about the longitudinal axis around the braid.

7. The implantable electrode lead according to claim 1, wherein the at least one electrode pole is electrically connected at a connection point a conductor of the plurality of conductors extending there-beneath.

8. The implantable electrode lead according to claim 1, wherein at least some conductors of the plurality of conductors are each associated with at least one accompanying which extends parallel to the particular conductor.

9. The implantable electrode lead according to claim 8, wherein the accompanying fiber is made of an electrically insulating material.

10. The implantable electrode lead according to claim 8, wherein each conductor, measured radially to the longitudinal axis has a first thickness and the associated at least one accompanying fiber has a second thickness, the second thickness being greater than the first thickness.

11. The implantable electrode lead according to claim 1, further comprising at least one electrical contact element electrically connecting the implantable electrode lead to an active device.

12. A method for producing an implantable electrode lead, comprising the steps of: providing at least one electrode pole; and providing a plurality of electrical conductors, at least one of which is to be electrically connected to the at least one electrode pole, the plurality of conductors being interconnected to form a braid extending along a longitudinal axis, at least one first conductor of the plurality of conductors being helically wound about the longitudinal axis in a first direction of rotation and at least one second conductor of the plurality of conductors being helically wound about the longitudinal axis in a second direction of rotation, which is opposite the first direction of rotation; and connecting the at least one electrode pole to at least one conductor of the plurality of conductors.

13. The method according to claim 12, wherein the at least one electrode pole has an opening, via which the at least one electrode pole is connected to at least one conductor of the plurality of conductors.

14. The method according to claim 12, wherein the braid in an initial state has a length, the plurality of electrical conductors extending along the length of the braid.

15. The method according to 12 wherein at least one conductor of the plurality of conductors is electrically interrupted at an interruption point.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various concepts underlying the present invention will be explained in greater detail hereinafter with reference to the exemplary embodiments shown in the figures, in which:

[0058] FIG. 1 shows a view of an exemplary embodiment of an electrode lead with electrical conductors braided into a braid;

[0059] FIG. 2 shows an enlarged sectional view of the detail X according to FIG. 1;

[0060] FIG. 3 shows a view of an exemplary embodiment of an electrode lead with a braid of conductors arranged on an inner tube;

[0061] FIG. 4 shows a cross-sectional view along the line A-A according to FIG. 3;

[0062] FIG. 5 shows a view of another exemplary embodiment of an electrode lead with a braid of conductors arranged on an inner tube;

[0063] FIG. 6 shows a cross-sectional view along the line B-B according to FIG. 5;

[0064] FIG. 7 shows a view of another exemplary embodiment of an electrode lead with a braid of conductors; and

[0065] FIG. 8 shows a schematic view of an electrode lead.

DETAILED DESCRIPTION

[0066] FIG. 1 shows a view of an exemplary embodiment of an electrode lead 1, which is to be connected at a proximal end 101 to an active device 2 and implanted with a distal end 100 in tissue G, for example in the human heart, to effect stimulation at a desired stimulation site, for example.

[0067] Such an electrode lead 1 may be used, for example, as a heart electrode lead for implantation in the human heart. Such an electrode lead 1, however, may also be designed as a neuroelectrode lead and thus may be implanted in the spinal cord or brain of a patient.

[0068] When used as a cardiac electrode lead, the active device 2 may be designed for example as a pacemaker, CRT device, defibrillator or electrophysiology device, for example for catheter ablation. The active device 2 may also be implanted in one embodiment. Alternatively, the active device 2 may also be operated outside the human body and thus may be connected to the electrode lead 1 outside the human body.

[0069] When used as a neuroelectrode lead, the active device 2 is designed for neurostimulation in the spinal cord or human brain (what is known as Spinal Cord Stimulation or Deep Brain Stimulation).

[0070] The electrode lead 1 has a plurality of electrode poles 130 arranged in the region of the distal end 100, which electrode poles form an electrode pole arrangement 13 and via which stimulation pulses may be emitted and signals detected. In contrast, a contact arrangement 14 with contact elements 140 is arranged at the proximal end 101 of the electrode lead 1 to form a plug (for example designed according to the IS4/DF4 standard) for electrical connection to an associated active device 2.

[0071] Inside an outer tube 10 formed by an outer sheath, electrical conductors are enclosed which serve to electrically connect the contact elements 140 to the electrode poles 130 and for this purpose extend along the length of the electrode lead 1 inside the outer tube 10.

[0072] In the electrode lead 1 as per the exemplary embodiment in FIG. 1, electrical conductors 121-124 are interwoven to form a braid 12, as shown in the views in FIGS. 2 to 4. First electrical conductors 121, 122 extend here helically in a first direction of rotation D1 (see FIG. 3) about a longitudinal axis A, along which the electrode lead 1 extends. Second conductors 123, 124, in contrast, are wound helically in a reverse direction of rotation D2 about the longitudinal axis A, with the conductors 123, 124 lying alternately one above the other and one below the other, thus forming a two-layer braid 12 on an inner tube 11 of the electrode lead 1.

[0073] The conductors 121-124 of the braid 12 each have an electrically conductive core which is encased by an insulating sheath so that the conductors 121-124 are electrically insulated from each other.

[0074] Even if the electrode lead 1 is implanted, medical examinations should be possible without restriction on the patient, in particular also an MRI examination, if necessary even within the scope of the implantation to verify the position of the electrode lead 1. Excessive heating due to a coupling-in of an electromagnetic field within the MRI examination must be avoided in order to exclude injury to a patient.

[0075] In the exemplary embodiment shown in FIGS. 1 to 4, a total of four conductors 121-124 are connected together to form a braid 12 and are wound helically around the inner tube 11. In the exemplary embodiment shown, the conductors 121-124 connect the contact elements 140 of the contact arrangement 14 at the proximal end 101 of the electrode lead 1 to the electrode poles 130 of the electrode pole arrangement 13 at the distal end 100 of the electrode lead 1. By selecting the pitch of the helically wound conductors 121-124 and thus by selecting the mesh spacing of the braid 12, the length of the conductors 121-124 may be adjusted so that electromagnetic excitation is effectively prevented at a predetermined MR excitation frequency.

[0076] The conductors 121-124 extend along the length of the electrode lead 1 and may preferably have the same length.

[0077] In the exemplary embodiment shown, an electrode pole 130, as shown in FIGS. 1 and 2, may be connected to an associated conductor 121 at a specific axial location, for example by producing a welded connection between the electrode pole 130 and the conductor 121. This may be done, for example, by what is known as hole closure welding, during the course of which—after removal of the insulation of conductor 121—an edging of an opening 131 of the electrode pole 130 is melted, and molten material of the electrode pole 130 thereby flows into the area of conductor 121 and thus establishes electrical contact, as may be seen in FIG. 2.

[0078] The fact that the electrode poles 130 are annular and the conductors 121-124 for forming the braid 12 extend helically around the inner tube 11 allows an exact axial positioning of the electrode poles 130, in particular in order to set and maintain a predetermined axial distance of the electrode poles 130 from each other. For this purpose, the electrode poles 130 are positioned and twisted on the braiding 12 in such a way that the particular opening 131 of an electrode pole 130 is aligned with an underlying, associated conductor 121-124, and thus a connection to the conductor 121-124 may be produced.

[0079] The braid 12 may have further conductors which are not to be connected (directly) to an electrode pole 130 or a contact element 140, but which serve as spur lines to extend the electrical length of the conductors which serve as feed lines and are in contact with the electrode poles 130.

[0080] This is shown schematically in FIG. 8. In this way, the braid 12 may be formed from conductors 121, 123 (helically extended, but shown by straight lines in FIG. 8 for reasons of simplified representation), which are wound about the longitudinal axis A of the electrode lead 1 in opposite directions of rotation D1, D2, wherein for example first conductors 121 wound in the first direction of rotation D1 are each electrically contacted at an associated connection point 132 with an associated electrode pole 130, whereas second conductors 123 wound oppositely in the second direction of rotation D2 are each electrically connected at an associated connection point 128 with an associated first conductor 121.

[0081] The conductor 121 is connected to the associated electrode pole 130 at the connection point 132 and extends beyond this to the distal end 100 of the electrode lead 1. In the region of the proximal end 101, the conductor 121 is connected to an associated contact element 140, but also extends beyond the contact element 140 to the end of the electrode lead 1. It is not necessary to cut a conductor 121 serving as a feed line, and therefore all conductors 121 serving as feed lines extend over the same length L corresponding to the total length of the electrode lead 1.

[0082] In the example shown, the second conductors 123 may be electrically cut at one or more interruption points 127, so that line portions of shorter length are created.

[0083] It should be noted that fundamentally different configurations of conductors serving as feed lines and conductors serving as spur lines may be created. In particular, first conductors 121 wound in the first direction of rotation D1 and/or second conductors 123 wound in the second direction of rotation D2 may be used as feed lines, and accordingly second conductors 123 wound in the second direction of rotation D2 and/or first conductors 121 wound in the first direction of rotation D1 may be used as spur lines.

[0084] By using conductors 121, 123, which extend along the entire length L of the electrode lead 1, as feed lines or as spur lines, and by electrically connecting a conductor serving as a feed line to another conductor serving as a spur line, the electrical length of a feed line may be doubled, it also being conceivable and possible to connect more than two conductors to each other, so that the effective electrical length of a feed line may also be extended beyond twice the length of the electrode lead 1.

[0085] In the exemplary embodiment in FIGS. 1 to 4, each conductor 121-124 is associated with two accompanying fibers 125, 126, which in each case—viewed along the longitudinal axis A of the electrode lead 1—are arranged on both sides of the associated conductor 121-124 and thus enclose the particular conductor 121-124 between them. As may be seen from the sectional view according to FIG. 4, the accompanying fibers 125, 126 each have a thickness B2 (measured radially in cross-section transversely to the longitudinal axis A) which is greater than the thickness B1 of the associated conductor 121-124. This has the effect that the conductors 121-124 are not in direct mechanical contact with each other, but are supported relative to each other via the accompanying fibers 125, 126, which protects io the conductors 121-124 from damage.

[0086] The accompanying fibers 125, 126 in each case may be permanently connected to the associated conductors 121-124. However, it is also conceivable and possible to lay the accompanying fibers 125, 126 loosely next to the conductors 121-124.

[0087] For production, the inner tube 11 is pushed onto a core that is rigid, for example, and the conductors 121-124 are braided around the inner tube 11 to form the braid 12, for example using a braiding machine. In this case, the accompanying fibers 125, 126 are braided together with the conductors 121-124.

[0088] After braiding the braid 12, the individual conductors 121-124 may be electrically connected to associated electrode poles 130 of the electrode pole arrangement 13 and to contact elements 140 of the contact arrangement 14. In addition, individual conductors 121-124 may be contacted with each other to create spur lines for extending the effective electrical length of a feed line. The spur line length may be adjusted as required by cutting individual conductors 121-124.

[0089] After configuring the braid 12 for the electrical connection of the electrode poles 130 to the contact elements 140, the outer tube 10 is formed on the braid 12. This may be achieved by overmoulding, for example. Alternatively, a reflow process may be used, within the scope of which tube portions are pushed onto the braid 12 and are connected by melting to form an outer sheath. The electrode poles 130 and the contact elements 140 remain accessible from the outside and are not encapsulated.

[0090] In an exemplary embodiment shown in FIGS. 5 and 6, in comparison to the exemplary embodiment shown in FIGS. 1 to 4, the braid 12 is formed from conductors 121-124, each of which is associated with only one accompanying fiber 125, 126. Otherwise, the exemplary embodiment according to FIGS. 5 and 6 is functionally identical to the exemplary embodiment according to FIGS. 1 to 4, and therefore reference should also be made to the previous comments.

[0091] In an exemplary embodiment shown in FIG. 7, conductors 121-124 of the braiding 12 of the electrode lead 1 do not have any accompanying fibers. In FIG. 7, an electrode pole 130 that is to be connected to a conductor 124 as feed line is shown as a dashed line. By contrast, a conductor 121 may serve as a spur line and is electrically cut at an interruption point 127. The conductor 121 may also be contacted with the conductor 124 at a connection point 132, where the electrode pole 130 is electrically contacted with the conductor 124, so that an electrical connection is created between the conductors 121, 124 themselves via the connection point 132 and also between the conductor 124 and the electrode pole 130.

[0092] In the exemplary embodiments shown, the conductors 121-124 are interwoven in two layers to form a braid 12, in such a way that the conductors 121-124 extend above and below each other alternately. The braid 12 is thus produced in one braiding plane and (in its basic form) extends in a tubular form about the longitudinal axis A of the electrode lead 1.

[0093] It is also conceivable in a different embodiment to form a braid 12 having a plurality of braiding planes, each braiding plane being made in two layers by means of conductors that are extended above and below each other alternately. In this way, the number of conductors of the electrode lead 1 may be increased.

[0094] The concepts underlying the present invention are not limited to the exemplary embodiments described above, but may also be realised in other variants.

[0095] An electrode lead of the type described here may be used, in principle, in very different applications with associated active devices, for example implantable active devices or also active devices to be used externally of a patient.

[0096] The use of a braid formed by conductors of the electrode lead results in a favourable laying of the conductors with good utilisation of the available installation space and flexible configurability of the electrode lead, especially with regard to MRI compatibility.

[0097] To produce the braid, multiple conductors may be braided simultaneously in an advantageous manner on an inner tube of the electrode lead, resulting in a tubular basic form which is flexible in its shape and may also be electrically configured by connecting the conductors to electrode poles, contact elements and to each other and by adapting the lengths of the conductors by local cutting.

[0098] In principle, the electrode lead may have any number of conductors, for example between two and several hundred conductors, which together form the braid.

[0099] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof. Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range, including the end points.

LIST OF REFERENCE SIGNS

[0100] 1 implantable electrode

[0101] 10 outer tube

[0102] 100, 101 end

[0103] 11 inner tube

[0104] 110 lumen

[0105] 12 braid

[0106] 121-124 Conductors

[0107] 125, 126 accompanying fibers

[0108] 127 interruption point

[0109] 128 connection point

[0110] 13 pole arrangement

[0111] 130 electrode pole

[0112] 131 opening

[0113] 132 connection point

[0114] 14 contact arrangement

[0115] 140 contact element

[0116] 2 active device

[0117] A longitudinal axis

[0118] B1, B2 thickness

[0119] D1, D2 direction of rotation

[0120] G tissue

[0121] L length