Circumferential ablation devices and methods
Methods and apparatuses are disclosed for providing pulsed electrical treatment (including high voltage, sub-microsecond pulsed electric energy) to body vessels. The apparatus may include deployable electrodes that conform to transitional surfaces. These apparatuses may include multiple wire loops forming petal-like electrodes configured to expand with an expandable member, such as a balloon.
1. An apparatus for delivering pulsed electric fields comprising:
an elongate body;
an expandable member at a distal end region of the elongate body;
a first electrode assembly comprising a first plurality of wire loops, each wire loop of the first plurality of wire loops forms a petal having a first active region, wherein the first active regions of each of the first plurality of wire loops are arranged around the expandable member and extend around all or at least a portion of a circumference of the expandable member; and
a second electrode assembly comprising a second plurality of wire loops, each wire loop of the second plurality of wire loops forms a petal having a second active region, wherein the second active regions of each of the second plurality of wire loops are arranged around the expandable member and extend around all or at least a portion of a circumference of the expandable member,
wherein the first electrode assembly is laterally offset from the second electrode assembly along a length of the expandable member, and wherein the first electrode assembly and the second electrode assembly are configured to expand radially outward when the expandable member is expanded.
2. The apparatus of claim 1 , wherein the expandable member comprises an expandable balloon.
3. The apparatus of claim 1 , wherein the first electrode assembly and the second electrode assembly extends from the elongate body over the expandable member.
4. The apparatus of claim 1 , wherein the first plurality of wire loops comprises between 2 and 5 loops and wherein the second plurality of wire loops comprises between 2 and 5 loops.
5. The apparatus of claim 1 , wherein each of the first active regions and each of the second active regions comprises a flexible bend, wherein an angle of the flexible bend is configured to expand as the expandable member is expanded.
6. The apparatus of claim 1 , wherein each wire loop of the first plurality of wire loops and each wire loop of the second plurality of wire loops are coupled to an outer surface of the expandable member at one or more spots.
7. The apparatus of claim 1 , wherein each wire loop of the first plurality of wire loops and each wire loop of the second plurality of wire loops are slidably coupled to an outer surface of the expandable member.
8. The apparatus of claim 1 , wherein each of the first active regions and each of the second active regions are bounded on either side by insulated regions.
9. The apparatus of claim 1 , wherein the first active region of each wire loop of the first plurality of wire loops is separated from the second active region of each wire loop of the second plurality of wire loops by a minimum distance, d.
10. The apparatus of claim 1 , wherein the first electrode assembly and the second electrode assembly are configured to flexibly conform to a wall of an anatomical structure.
11. The apparatus of claim 1 , wherein the first electrode assembly and the second electrode assembly are each formed of a wire having a diameter of less than 0.2 mm.
12. The apparatus of claim 1 , wherein the first electrode assembly is configured to have a first polarity and the second electrode assembly is configured to have a second polarity.
13. An apparatus for delivering pulsed electric fields comprising:
an elongate body;
a balloon on the elongate body;
a first electrode assembly comprising a first plurality of wire loops, each wire loop of the first plurality of wire loops forms a petal having a first active region arranged on the balloon; and
a second electrode assembly comprising a second plurality of wire loops, each wire loop of the second plurality of wire loops forms a petal having a second active region arranged on the balloon,
wherein each of the first active regions and each of the second active regions comprises a flexible bend, an angle of the flexible bend is configured to expand as the balloon is expanded so that the first electrode assembly and the second electrode assembly expands radially outward when the balloon is expanded, further wherein the first electrode assembly is laterally offset from the second electrode assembly along a length of the balloon.
14. The apparatus of claim 13 , wherein the first plurality of wire loops comprises between 2 and 8 loops and wherein the second plurality of wire loops comprises between 2 and 8 loops.
15. The apparatus of claim 13 , wherein each wire loop of the first plurality of wire loops and each wire loop of the second plurality of wire loops are coupled to an outer surface of the balloon at one or more spots.
16. The apparatus of claim 13 , wherein each wire loop of the first plurality of wire loops and each wire loop of the second plurality of wire loops are positioned over an outer surface of the balloon.
17. The apparatus of claim 13 , wherein each of the first active regions and each of the second active regions are bounded on either side by insulated regions.
18. The apparatus of claim 13 , wherein the first active region of each wire loop of the first plurality of wire loops is spaced apart from the second active region of a wire loop of the second plurality of wire loops by a fixed distance.
19. The apparatus of claim 13 , wherein the first electrode assembly and the second electrode assembly are configured to flexibly conform to a wall of an anatomical structure.
20. The apparatus of claim 13 , wherein the first electrode assembly and the second electrode assembly are each formed of a wire having a diameter of less than 0.2 mm.
21. The apparatus of claim 13 , wherein the first electrode assembly is configured to have a first polarity and the second electrode assembly is configured to have a second polarity.
22. The apparatus of claim 13 , comprising a plurality of first electrode assemblies having a first polarity and a plurality of second electrode assemblies having a second polarity, wherein each first electrode assembly of the plurality of first electrode assemblies alternate with and laterally offset from each second electrode assembly of the plurality of second electrode assemblies.
23. The apparatus of claim 13 , wherein the first electrode assembly and the second electrode assembly are shape set to return to a radially collapsed or constricted configuration when the balloon is contracted.