Implantable flexible circuit leads and methods of use
Devices, systems and methods are provided for stimulation of tissues and structures within a body of a patient. In particular, implantable leads are provided which are comprised of a flexible circuit. Typically, the flexible circuit includes an array of conductors bonded to a thin dielectric film. Example dielectric films include polyimide, polyvinylidene fluoride (PVDF) or other biocompatible materials to name a few. Such leads are particularly suitable for stimulation of the spinal anatomy, more particularly suitable for stimulation of specific nerve anatomies, such as the dorsal root (optionally including the dorsal root ganglion).
1. A system for stimulating the dorsal root ganglion of a patient, comprising:
a first elongate flexible implantable dielectric structure comprising a first proximal end adapted to receive first stimulation pulses from an implantable pulse generator, a first distal end adapted to apply the first stimulation pulses to the dorsal root ganglion of the patient, and a first medial portion connecting the first proximal end and the first distal end, wherein the first distal end comprises a first electrode; and
a second elongate flexible implantable dielectric structure comprising a second proximal end adapted to receive second stimulation pulses from the implantable pulse generator, a first distal end adapted to apply the second stimulation pulses to the dorsal root ganglion of the patient, and a second medial portion connecting the second proximal end and the second distal end, wherein the second distal end comprises a second electrode;
wherein the first and second proximal ends and first and second medial portions are bonded together along a central longitudinal axis so that the first and second elongate flexible implantable dielectric structures are configured to extend lengthwise along the central longitudinal axis, wherein the first and second electrodes are disposed on first and second inner surfaces of the first and second distal ends respectively and are configured to be implanted at least partially within a vertebral foramen containing the dorsal root ganglion to direct stimulation energy toward the central longitudinal axis;
wherein at least one of the first and second distal ends is configured to move away from the central longitudinal axis while the first and second proximal ends are joined to allow the dorsal root ganglion to be positioned at least partially between the first and second distal ends to receive the stimulation energy that is directed by the first and second electrodes toward the central longitudinal axis.
2. A system as in claim 1 , wherein the first distal end is movable by recoil force.
3. A system as in claim 1 , wherein the first distal end is attachable to a first obturator which is capable of moving the first distal end.
4. A system as in claim 3 , wherein the first obturator is configured to dissect tissue while it moves the first distal end.
5. A system as in claim 3 , wherein the first obturator is advanceable from a delivery device so as to advance the first distal end and move the first distal end away from the second distal end.
6. A system as in claim 1 , wherein the first elongate structure and the second elongate structure comprise a dielectric film.
7. A system as in claim 6 , wherein the first dielectric film and the second dielectric film has a thickness in the range of approximately 7.5 to 125 μm.
8. A system as in claim 6 , wherein the first dielectric film and the second dielectric film has a thickness in the range of approximately 0.5-2 mils.
9. A system as in claim 1 , further comprising: a first contact pad and a first conductive trace extending from the first contact pad to the first electrode, a second contact pad and a second conductive trace extending from the second contact pad to the second electrode, wherein the first contact pad and the second contact pad provide electrical connection from the first electrode and the second electrode to the implantable pulse generator.
10. A system as in claim 1 , wherein the first and second distal ends are passable through a needle.
11. A system as in claim 1 , wherein the first distal end of the first elongate structure includes at least one fold, wherein the first distal end is configured to pass through a delivery device while in an unfolded position and wherein the first distal end deploys upon release from the delivery device toward a folded position.
12. A system as in claim 11 , wherein the second distal end includes at least one fold, wherein the second distal end is configured to pass through the delivery device while in an unfolded position and wherein the second distal end deploys upon release from the delivery device toward a folded position so that the first and second distal ends deploy by moving away from each other so as to at least partially surround the dorsal root ganglion.
13. A system as in claim 12 , wherein the first and second distal ends move independently.
14. A system as in claim 12 , wherein the deployed first and second distal ends together form a V-shape.
15. A system as in claim 11 , wherein the first and second distal ends are configured to be passable through a needle prior to deployment.
16. A system as in claim 11 , wherein the first inner surface faces away from the at least one fold.
17. A system as in claim 16 , wherein the first proximal end has at least one contact pad, wherein the at least one contact pad is disposed on an opposite surface of the first inner surface and faces the at least one fold.
18. A system as in claim 17 , wherein the at least one fold is disposed between the first electrode and the at least one contact pad.
19. A system as in claim 1 , wherein the at least one of the first and second distal ends are moveable away from the longitudinal axis by bending or curving.
20. A system as in claim 1 , wherein the at least one of the first and second distal ends are moveable away from the longitudinal axis by folding.