Implantable, expandable, multicontact electrodes and tools for use therewith

• US 6,522,932 B1
• Filed: 02/13/2001
• Issued: 02/18/2003
• Est. Priority Date: 02/10/1998
• Status: Expired due to Term

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Kuzma, Janusz A., Mann, Carla M.
• Primary Examiner(s): WILSON, GREGORY A
• Application Number:
  US09/783,237
• Time in Patent Office: 735 Days
• Field of Search: 607/115, 607/116, 607/117, 607/152, 600/373, 600/374, 600/377
• US Class Current: 607/116
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0553 Paddle shaped electrodes, e.g. for laminotomy

Abstract

A paddle-type electrode or electrode array is implantable like a percutaneously inserted lead, i.e., without requiring major surgery, and once implanted, expands to provide a platform for many electrode configurations. The electrode array is provided on a flexible, foldable, subcarrier or substrate. Such subcarrier or substrate folds or compresses during implantation, thereby facilitating its insertion using percutaneous implantation techniques and tools. Once implanted, such subcarrier or substrate expands, thereby placing the electrodes in a desired spaced-apart positional relationship, and thus achieving a desired electrode array configuration. A steering stylet may be accommodated in a lumen provided in the subcarrier or substrate. Insertion tools useful with such electrode arrays include a needle with an oblong cross-section, which accommodates the dimensions of the folded array, and also accommodates other electrode arrays that are not necessarily folded.

Claims

1. An implantable electrode array comprising:

a compliant biocompatible substrate configured as two columns, the substrate substantially following the outer edge of a paddle shape;

a plurality of electrode contacts carried on the substrate;

conductive wires within the substrate for making electrical contact with each of the plurality of electrode contacts; and

a shape memory element integral with the substrate;

whereby the electrode array is foldable to assume a small cross-sectional area during implantation, but whereby the electrode array unfolds to assume an expanded configuration as controlled by the shape memory element after implantation.

2. The implantable electrode array of claim 1 further comprising a flexible membrane formed inside the area formed by the substantially paddle shaped substrate.

3. The implantable electrode array of claim 1 wherein the shape memory element comprises a wire made from at least one of metal and polymer.

4. An implantable electrode array comprising:

a compliant biocompatible substrate having a width greater than a height;

a plurality of electrode contacts carried on the substrate;

conductive wires within the substrate for making electrical contact with each of the plurality of electrode contacts;

a lumen within the compliant biocompatible substrate, which lumen accepts a stylet for steering the electrode array during implantation;

whereby the electrode array is foldable to assume a small cross-sectional area during implantation, but whereby the electrode array unfolds to assume an expanded configuration as controlled by the shape of the compliant biocompatible substrate after implantation.

5. The implantable electrode array of claim 4 wherein the lumen within the substrate extends through the substrate to an opening at a distal end of the electrode array.

6. The implantable electrode array of claim 4 wherein the lumen within the substrate extends substantially through the substrate.

7. The implantable electrode array of claim 4 wherein the substrate is foldable along an axis substantially parallel to the substantially parallel columns, said axis lying in the region of the flexible substrate between the columns of electrodes.

8. The implantable electrode array of claim 4 wherein the plurality of electrodes are spaced-apart in at least two substantially parallel columns.

9. The implantable electrode array of claim 8 wherein the number of substantially parallel columns of spaced-apart electrodes comprises three.

10. The implantable electrode array of claim 4 wherein the flexible substrate has a width of between about 6.5 and 7.0 mm and a length of about 8-12 mm, and wherein each column of electrodes has a height of between about 0.6 and 1.0 mm, and wherein the flexible substrate has a height in the region between the electrode columns of approximately 0.10 to 0.30 mm.

11. A system for implanting an expandable electrode array comprising:

an electrode array, the electrode array comprising;

a compliant biocompatible substrate;

a plurality of electrodes integral with a surface of the substrate; and

conductive wires for making electrical contact with each electrode in the plurality of electrodes;

the flexible substrate normally assuming a substantially flat shape, but being collapsible so as to configure the electrode array in a folded or compressed state; and

an insertion tool configured to facilitate implantation of the electrode array into living tissue while the electrode array is still in a folded or compressed state.

12. The system of claim 11 wherein the plurality of electrodes are spaced-apart in at least two substantially parallel columns.

13. The system of claim 12 wherein the number of substantially parallel columns of spaced-apart electrodes comprises three.

14. The system of claim 11 wherein the insertion tool comprises a hollow cylinder wherein the folded or compressed electrode array may be inserted and a distal tip configured to allow expulsion of the electrode array into living tissue, wherein the cylinder is oblong in cross-section.

15. The system of claim 14 further comprising a removable core stylet insertable into the lumen of the cylinder, which stylet has an oblong cross-section similar to the dimensions of the lumen.

16. The system of claim 11 further comprising a loading tool detachably connected to a proximal end of the insertion tool, the loading tool having a shape that facilitates configuring the electrode array in its folded or compressed state from its substantially flat state as such electrode array is longitudinally inserted into the insertion tool.

17. A system for implanting a foldable or compact electrode array comprising:

a foldable or compact electrode array, the electrode array comprising;

a compliant biocompatible substrate;

a plurality of electrodes integral with a surface of the substrate; and

conductive wires for making electrical contact with each electrode in the plurality of electrodes; and

an insertion tool configured to facilitate implantation of the electrode array into living tissue, the insertion tool comprising;

a cylinder defining a lumen for accepting the foldable or compact electrode array; and

a distal tip configured to allow expulsion of the electrode array into living tissue;

wherein the cylinder is oblong in cross-section.

18. The system of claim 17 further comprising a removable core stylet insertable into the lumen of the cylinder, which stylet has an oblong cross-section similar to the dimensions of the lumen.

19. The system of claim 17 further comprising a loading tool detachably connected to a proximal end of the insertion tool, the loading tool having a shape that facilitates configuring the electrode array in its folded or compressed state from its substantially flat state as such electrode array is longitudinally inserted into the insertion tool.

20. A method of implanting an expandable electrode array through the lumen of a needle, comprising:

forming an electrode array having a plurality of substantially parallel columns of spaced apart electrodes on a flexible substrate and a lumen within the substrate configured to accept a steering stylet;

providing a needle having a lumen therethrough and a distal tip configured to allow expulsion of the electrode array into living tissue;

providing a removable core stylet insertable into the lumen of the needle;

inserting the core stylet into the lumen of the needle;

injecting the needle into living tissue;

removing the core stylet from the lumen of the needle;

inserting the steering stylet into the lumen of the electrode array;

folding the columns of electrodes against each other;

inserting the folded columns into the lumen of the needle;

using the steering stylet to expel the folded columns of electrodes from the lumen of the needle into the living tissue; and

unfolding the columns of electrodes to form a paddle-type array of substantially parallel columns of electrodes.

21. The method of claim 20 wherein the needle is oblong in cross-section.

22. The method of claim 20 further comprising providing a loading tool detachably connected to a proximal end of the needle, the loading tool having a shape that facilitates folding the columns of electrodes against each other, and wherein folding the columns of electrodes against each other and inserting the folded columns into the lumen of the needle comprise inserting the electrode array through the loading tool and into the needle.

23. A method of implanting a foldable or compact electrode array through the lumen of a needle, composing:

forming an electrode array having a plurality of substantially parallel columns of spaced apart electrodes on a flexible substrate;

providing a needle having an oblong lumen therethrough and a distal tip configured to allow expulsion of the electrode array into living tissue;

providing a removable core stylet insertable into the lumen of the needle;

inserting the core stylet into the lumen of the needle;

injecting the needle containing the core stylet into living tissue;

removing the core stylet from the lumen of the needle;

inserting the electrode array into the lumen of the needle;

expelling the electrode array into the living tissue.

24. The method of claim 23 wherein the electrode array includes a lumen within the substrate configured to accept a steering stylet, and further comprising inserting the steering stylet into the lumen of the electrode array and using the steering stylet to expel the electrode array from the lumen of the needle into the living tissue.