Inductively heated snare

1. A thermally adjustable surgical tool comprising:

an applicator and a snare forming a thermal element for receiving oscillating electrical current from a power source, the thermal element comprising a single electrical conductor forming a loop and being at least partially disposed in the applicator, and having at least one ferromagnetic coating covering at least a portion of the single electrical conductor;

wherein the single electrical conductor forms part of a return pathway for the oscillating electrical current distal to the ferromagnetic coating and is configured such that a majority of the oscillating electrical current remains in the thermal element as it passes out of and back into the applicator; and

wherein the at least one ferromagnetic coating is sufficiently thin that the at least one ferromagnetic coating will not fracture when the at least one ferromagnetic coating is heated in air and then immersed in liquid while the at least one ferromagnetic coating is heated.

2. The thermally adjustable surgical tool of claim 1 , further comprising a conductive pathway for connecting the power source to the single electrical conductor for delivering the oscillating electrical current to the single electrical conductor to thereby heat the at least one ferromagnetic coating.

3. The thermally adjustable surgical tool of claim 2 , wherein the power source is configured to provide a sufficient amount of the oscillating electrical current through the single electrical conductor to heat the at least one ferromagnetic coating to cause hemostasis in tissue contacted by the at least one ferromagnetic coating.

4. The thermally adjustable surgical tool of claim 2 , wherein the conductive pathway and the thermal element form a tuned circuit for optimizing power delivery to the at least one ferromagnetic coating.

5. The thermally adjustable surgical tool of claim 4 , further comprising a control mechanism for adjusting a frequency of the oscillating electrical current to thereby optimize power delivery to the at least one ferromagnetic coating.

6. The thermally adjustable surgical tool of claim 4 , further comprising a matching circuit wherein the power source has an output impedance and the thermal element has an input impedance, wherein the matching circuit is configured to match the output impedance with the input impedance.

7. The thermally adjustable tool of claim 2 , wherein the power source is configured to heat the at least one ferromagnetic coating by inductive heating.

8. The thermally adjustable surgical tool of claim 1 , wherein the at least one ferromagnetic coating comprises a plurality of ferromagnetic coatings disposed along the loop.

9. The thermally adjustable surgical tool of claim 1 , wherein the applicator is a ring.

10. The thermally adjustable tool of claim 1 , wherein the at least one ferromagnetic coating comprises an elongate coating extending along the single electrical conductor.

11. The thermally adjustable tool of claim 10 , wherein at least a portion of the single electrical conductor is disposed in the applicator and wherein the elongate coating is deployable from the applicator such that at least a portion of the single electrical conductor not covered by the elongate coating is located outside the applicator when the elongate coating is deployed.

12. The thermally adjustable tool of claim 1 , wherein the at least one ferromagnetic coating surrounds the single electrical conductor.

13. The thermally adjustable tool of claim 1 , wherein the at least one ferromagnetic coating is generally arcuate and extends along a portion of the loop formed by the single electrical conductor.

14. A thermally adjustable surgical tool comprising:

an electrical conductor;

a ferromagnetic coating covering a portion of the electrical conductor to form a heating region along the portion of the electrical conductor coated with the ferromagnetic coating of the electrical conductor;

a power source disposed in electrical communication with the electrical conductor configured to deliver an oscillating current to the electrical conductor to thereby generate heat in the ferromagnetic coating; and

a tube configured to contain the electrical conductor, the portion of the electrical conductor coated with the ferromagnetic coating being deployable from the tube;

wherein the heating region is configured to contact tissue and thereby treat the tissue with the heat generated in the ferromagnetic coating without passing a substantial amount of the oscillating current through the tissue; and

wherein the ferromagnetic coating is sufficiently thin to not fracture when exposed to a temperature differential sufficiently large to cause a ferrite bead to fracture.

15. The thermally adjustable surgical tool of claim 14 wherein the electrical conductor forms a loop.

16. A surgical tool comprising:

an applicator;

an electrical conductor having a distal end forming a loop and two arms extending away from the loop; and

a ferromagnetic coating covering only the distal end of the electrical conductor forming the loop so as to form a substantially semi-circular ferromagnetic coating along the loop;

wherein the two arms are extendable from or extending from the applicator, and wherein the arms are not covered by a ferromagnetic coating; and

wherein the ferromagnetic coating will not fracture when repeatedly heated and immersed in liquid while still hot.

17. The surgical tool of claim 16 , further comprising a tube, and wherein the electrical conductor is deployably disposed in the tube and wherein the ferromagnetic coating can be withdrawn into the tube.

18. A thermal surgical tool comprising:

an applicator;

a flexible electrical conductor at least partially disposable within the applicator;

an arcuate ferromagnetic coating covering a portion of the flexible electrical conductor; and

a non-stick coating covering at least the arcuate ferromagnetic coating; and

wherein the arcuate ferromagnetic coating, when heated, is movable between air and liquid without causing fracturing of the arcuate ferromagnetic coating.

19. The thermal surgical tool of claim 18 , wherein the flexible electrical conductor is deployable from the applicator.

20. The thermal surgical tool of claim 19 , wherein the flexible electrical conductor forms a loop.

21. The thermal surgical tool of claim 20 , wherein the loop formed by the flexible electrical conductor has a first width when at least partially disposed within the applicator and wherein the loop is expandable when deployed from the applicator such that the loop has a second width when deployed from the applicator, and wherein the first width is less than the second width.

22. The thermal surgical tool of claim 18 , wherein the flexible electrical conductor forms a loop extendable from the applicator, and wherein the arcuate ferromagnetic coating covers a distal portion of the loop generally opposite the applicator, the arcuate ferromagnetic coating being wider than a distal end of the applicator when the loop is extended from the applicator.

23. A thermal surgical tool comprising:

an electrical conductor forming a loop and having a first section and second section;

a thermally adjustable ferromagnetic coating covering a portion of the electrical conductor between the first section and second section;

wherein the electrical conductor is at least partially disposable within a tube and the loop formed by the electrical conductor has a first width when disposed within the tube;

wherein the electrical conductor is deployable from the tube and the loop has a second width when deployed from the tube;

wherein the first width is less than the second width;

wherein a portion of the first section or the second section not covered with the thermally adjustable ferromagnetic coating is located outside the tube when the electrical conductor is deployed; and

wherein the adjustable ferromagnetic material, when heated, is movable between air and liquid without causing the thermally adjustable ferromagnetic coating to crack.

24. The thermal surgical tool of claim 23 , further comprising an electrical circuit configured to deliver oscillating electrical energy to the electrical conductor by electrically connecting the electrical circuit to the first section and to the second section of the electrical conductor independent of the thermally adjustable ferromagnetic coating.

25. The thermal surgical tool of claim 24 , wherein the electrical circuit comprises an impedance matching circuit.

26. The thermal surgical tool of claim 23 , wherein a plurality of thermally adjustable ferromagnetic coatings are disposed on the electrical conductor.

27. The thermal surgical tool of claim 23 , wherein the thermally adjustable ferromagnetic coating is circumferentially disposed about the electrical conductor.

28. A thermal surgical tool comprising:

a conductor having a first section and a second section, a portion of the electrical forming a loop;

a ferromagnetic coating covering a portion of the conductor between the first section and the second section; and

a power source attached to the conductor independent of the ferromagnetic coating such that passing electrical energy through the conductor heats the ferromagnetic coating;

wherein the conductor is at least partially disposed within an applicator; and

wherein substantially all the electrical energy delivered to the conductor flows through the conductor and is substantially contained within the conductor and the ferromagnetic coating; and

wherein the ferromagnetic coating, when heated, is moveable between a first environment and a second environment without causing the ferromagnetic coating to fracture even when the first environment and the second environment have a large temperature differential.

29. The thermal surgical tool of claim 28 , wherein a plurality of spaced apart ferromagnetic coatings are disposed on the electrical conductor.