Optimization of energy delivery for various applications
Pulsed electric fields (PEFs) are transmitted to a body lumen or passageway in a manner which provides focal therapy. In some embodiments, PEFs are delivered through independent electrically active electrodes of an energy delivery body, typically in a monopolar fashion. Such delivery concentrates the electrical energy over a smaller surface area, resulting in stronger effects than delivery through an electrode extending circumferentially around the lumen or passageway. It also forces the electrical energy to be delivered in a staged regional approach, mitigating the effect of preferential current pathways through the surrounding tissue. Focal delivery of PEFs can provide increased tissue lethality by employing precise timing and sequencing of energy delivery to the electrodes.
1. A method of treating a passageway within a body wherein the passageway has an inner circumference, the method comprising:
positioning a plurality of electrodes within the passageway so that the plurality of electrodes spans the inner circumference of the passageway;
creating a first treatment area along a first portion of the inner circumference of the passageway by providing pulsed electric field energy to at least one of the plurality of electrodes so as to prioritize energy delivery through the at least one of the plurality of electrodes to the first treatment area so as to destroy at least a portion of cells within a cellular matrix along the first treatment area without destroying the cellular matrix along the first treatment area; and
creating at least one additional treatment area along at least one additional portion of the inner circumference of the passageway by providing pulsed electric field energy to at least one of the plurality of electrodes so as to prioritize energy delivery through the at least one of the plurality of electrodes to the at least one additional treatment area so as to destroy at least a portion of cells within a cellular matrix along the at least one additional treatment area without destroying the cellular matrix along the at least one additional treatment area,
wherein the first portion and the at least one additional portion extends along the inner circumference so as to create a functionally continuous treatment area spanning the inner circumference.
2. A method as in claim 1 , wherein the passageway is disposed within a heart and the functionally continuous treatment area comprises an electrical disconnection between a pulmonary vein and a left atrium so as to treat arrhythmia.
3. A method as in claim 2 , wherein the passageway comprises the pulmonary vein.
4. A method as in claim 1 , wherein the functionally continuous treatment area comprises a transmural lesion.
5. A method as in claim 1 , wherein the passageway comprises an airway within a lung and the functionally continuous treatment area creates a vacancy of cell types while maintaining a cartilage layer of the airway.
6. A method as in claim 5 , wherein the cell types include epithelial cells, goblet cells and/or submucosal gland cells.
7. A method as in claim 5 , wherein the functionally continuous treatment area has a depth of up to and not beyond 2.5 cm.
8. A method as in claim 1 , wherein the pulsed electric field energy is biphasic.
9. A method as in claim 1 , wherein creating the first treatment area along the first portion of the inner circumference of the passageway is achieved by providing pulsed electric field energy to the at least one of the plurality of electrodes for less than or equal to 10,000 μs.
10. A method as in claim 9 , wherein creating the first treatment area along the first portion of the inner circumference of the passageway is achieved by providing pulsed electric field energy to the at least one of the plurality of electrodes for less than or equal to 500 μs.
11. A method as in claim 9 , wherein creating the first treatment area along the first portion of the inner circumference of the passageway is achieved by providing pulsed electric field energy to the at least one of the plurality of electrodes for 5 μs-50 μs.
12. A method as in claim 1 , wherein the pulsed electric field energy is comprised of 40-500 packets.
13. A method as in claim 12 , wherein the pulsed electric field energy is comprised of up to 10 packets.
14. A method as in claim 1 , wherein the pulsed electric field energy is delivered in a monopolar arrangement.
15. A method as in claim 1 , wherein the at least one additional portion comprises two to seven additional portions.
16. A method as in claim 1 , wherein the pulsed electric field energy is provided to the plurality of electrodes in a manner so that the first treatment area and the at least one additional treatment area are created in series.
17. A method as in claim 1 , wherein the first treatment area and the at least one additional treatment area overlap.
18. A method as in claim 1 wherein creating the first treatment area comprises providing the pulsed electric field energy to the first treatment area in a plurality of phases.
19. A method as in claim 18 , wherein creating the at least one additional treatment area comprises providing the pulsed electric field energy to the at least one additional treatment area in a plurality of differing phases, wherein the plurality of phases and the plurality of differing phases do not coincide.
20. A method as in claim 19 , wherein creating the at least one additional treatment area comprises providing the pulsed electric field energy to the at least one additional treatment area in a plurality of differing phases, wherein the plurality of phases and the plurality of differing phases form a repetitive pattern.
21. A method as in claim 19 , further comprising providing maintenance pulsed electric field energy to the first treatment area and/or the at least one additional treatment area in between phases, wherein the maintenance pulsed electric field energy has a lower voltage than the pulsed electric field energy.
22. A method as in claim 21 , wherein the maintenance pulsed electric field energy has a voltage of less than half that of the pulsed electric field energy.
23. A method as in claim 1 wherein the plurality of electrodes comprise a plurality of electrodes mounted on or imbedded in an expandable member, wherein positioning the plurality of electrodes comprises expanding the expandable member.
24. A method as in claim 1 , wherein the plurality of electrodes comprises a plurality of wires or ribbons forming an electrode delivery body.
25. A method as in claim 24 , wherein the plurality of wires or ribbons forming an electrode delivery body having an expandable basket shape wherein a portion of the basket shape is insulated, and wherein positioning the plurality of electrodes comprises expanding the electrode delivery body.