Renal nerve neuromodulation device

1. A neuromodulation device for use in a vessel having an endothelium and carrying body fluid with a fluid pressure, comprising:

a) an elongate flexible introducer having a proximal end and distal end;

b) an expandable ablation valve at said distal end of said introducer, said ablation valve having a proximal surface, a distal surface, a circumference, and a plurality of electrodes displaced about said circumference, said ablation valve adapted to dynamically react to fluid pressure within the vessel such that,

i) when a pressure within and on said distal surface of said ablation valve is less than the fluid pressure on said proximal surface of said ablation valve, said ablation valve is in a retreated configuration in which said electrodes are configured to be out of circumferential contact with the endothelium of the vessel, and

ii) when said pressure within and on said distal surface of said ablation valve is greater than the fluid pressure on said proximal surface of said ablation valve, said ablation valve is in a contact configuration in which said electrodes are configured to be in circumferential contact with the endothelium of the vessel; and

c) a conductor extending along said introducer, said conductor having a distal end electrically coupled to said electrodes of said ablation valve and a proximal end extended to a terminal for coupling to a RF generator.

2. A neuromodulation device according to claim 1 , wherein:

said introducer is a catheter defining a lumen having a distal opening that is located at an interior of said ablation valve.

3. A neuromodulation device according to claim 1 , wherein:

a proximal end of said ablation valve is located substantially coincident with said distal opening of said lumen.

4. A neuromodulation device according to claim 1 , wherein:

said ablation valve expands to said contact configuration during diastole, and moves to said retreated configuration during systole.

5. A neuromodulation device according to claim 1 , wherein:

said ablation valve comprises an inner layer defined by electrospun fibers, and an expandable structure over said inner layer comprising a braid of filaments which cross over each other, at least a plurality of said filaments having a spring bias to assume a preferred crossing angle relative to each other, a proximal end of said braid of filaments radially collapsed and coupled to the distal end of said elongate introducer.

6. A neuromodulation device according to claim 5 , wherein:

in each of said contact configuration and said retreated configuration, said ablation valve has respective frustoconical shapes.

7. A neuromodulation device according to claim 5 , wherein:

said filaments define at least a plurality of electrodes.

8. A neuromodulation device according to claim 7 , wherein:

said filaments comprise insulated wires, and each said electrode is defined at a portion of said wire at which a portion of the insulation has been removed to expose an interior conductive metal of said wire.

9. A neuromodulation device according to claim 7 , wherein:

said filaments include non-conductive filaments.

10. A neuromodulation device according to claim 7 , wherein:

an outer layer of electrospun fibers provided over said filaments.

11. A neuromodulation device according to claim 7 , wherein:

said device is bipolar.

12. A neuromodulation device according to claim 11 , wherein:

said electrodes includes first and second electrically isolated sets of electrodes, and said conductor comprises first and two electrically isolated conductors, said first conductor electrically coupled to said first set of electrodes, and said second electrode coupled to said second set of electrodes.

13. A neuromodulation device according to claim 7 , wherein:

said device is monopolar.

14. A neuromodulation device according to claim 1 , further comprising:

a sleeve into which said introducer and ablation valve are provided for delivery to a treatment site, said introducer longitudinally displaceable relative to said sleeve to advance said ablation valve out of a distal end of said sleeve.

15. A neuromodulation device according to claim 1 , further comprising:

an inner catheter having a proximal end and a distal end and extending through said introducer, wherein a distal end of said ablation valve is coupled to said distal end of said inner catheter, and said inner catheter and introducer are longitudinally translatable relative to each other to move said ablation valve between said open and closed configurations.

16. A neuromodulation device according to claim 1 , further comprising:

said RF generator electrically coupled to said terminal.

17. A neuromodulation device for use in a vessel having an endothelium and carrying body fluid with a fluid pressure, comprising:

a) an elongate flexible introducer having a proximal end and distal end;

b) an expandable ablation valve at said distal end of said introducer, said ablation valve having a first surface, an opposing second surface, a circumference, and a plurality of electrodes displaced about said circumference, said ablation valve adapted to dynamically react to fluid pressure within the vessel such that,

i) when a pressure within and on said second surface of said ablation valve is less than the fluid pressure on said first surface of said ablation valve, said ablation valve is in a retreated configuration in which said electrodes are configured to be out of circumferential contact with the endothelium of the vessel, and

ii) when said pressure within and on said second surface of said ablation valve is greater than the fluid pressure on said first surface of said ablation valve, said ablation valve is in a contact configuration in which said electrodes are configured to be in circumferential contact with the endothelium of the vessel; and

c) a conductor extending along said introducer, said conductor having a distal end electrically coupled to said electrodes of said ablation valve and a proximal end extended to a terminal for coupling to a RF generator.