Catheter with inductively heated regions

• US 8,506,561 B2
• Filed: 12/24/2009
• Issued: 08/13/2013
• Est. Priority Date: 04/17/2009
• Status: Active Grant

• Current Assignee: Domain Surgical, Inc (OmniGuide Holdings, Inc.)
• Original Assignee: Domain Surgical, Inc (OmniGuide Holdings, Inc.)
• Inventors: McNally, David, Manwaring, Kim
• Primary Examiner(s): Dvorak, Linda
• Assistant Examiner(s): DELLA, JAYMI E
• Application Number:
  US12/647,358
• Publication Number:
  US 20100268215A1
• Time in Patent Office: 1,328 Days
• Field of Search: 606/47, 606/113, 607/103
• US Class Current: 606/31
• CPC Class Codes: A61B 17/00234 for minimally invasive surgery A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/320068 using mechanical vibrations, e.g. ultrasonic A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745
• CPC Class Codes: A61B 17/3211 Surgical scalpels, knives; Accessories therefor
• CPC Class Codes: A61B 18/04 by heating by applying electromagnetic radiation A61B18/18; hyperthermia using electric or magnetic fields, radiation or ultrasound A61N
• CPC Class Codes: A61B 18/08 by means of electrically-heated probes
• CPC Class Codes: A61B 18/082 Probes or electrodes therefor
• CPC Class Codes: A61B 18/085 Forceps, scissors
• CPC Class Codes: A61B 18/10 Power sources therefor
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00141 continuous, e.g. wave
• CPC Class Codes: A61B 2017/00876 magnetic
• CPC Class Codes: A61B 2017/00973 pedal-operated
• CPC Class Codes: A61B 2017/320069 for ablating tissue
• CPC Class Codes: A61B 2017/32007 with suction or vacuum means
• CPC Class Codes: A61B 2017/320082 for incising tissue
• CPC Class Codes: A61B 2018/00077 high, i.e. electrically conducting
• CPC Class Codes: A61B 2018/00095 high, i.e. heat conducting
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61B 2018/0013 non-sticking
• CPC Class Codes: A61B 2018/00577 : Ablation
• CPC Class Codes: A61B 2018/00589 : Coagulation
• CPC Class Codes: A61B 2018/00595 : Cauterization
• CPC Class Codes: A61B 2018/00601 : Cutting
• CPC Class Codes: A61B 2018/00619 : Welding
• CPC Class Codes: A61B 2018/00642 : with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00654 : with individual control of each of a plurality of energy emitting elements
• CPC Class Codes: A61B 2018/00702 : Power or energy
• CPC Class Codes: A61B 2018/00714 : Temperature
• CPC Class Codes: A61B 2018/00755 : Resistance or impedance
• CPC Class Codes: A61B 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00803 : with temperature prediction
• CPC Class Codes: A61B 2018/00958 : for switching between different working modes of the main function
• CPC Class Codes: A61B 2018/128 : generating two or more frequencies
• CPC Class Codes: A61B 2018/1407 : Loop
• CPC Class Codes: A61B 2018/1412 : Blade
• CPC Class Codes: A61M 25/00 : Catheters; Hollow probes dilators A61M29/00; peritoneal catheters A61M1/285; tracheal tubes A61M16/04; for drainage A61M27/00; for uterus, vagina or rectum A61M31/00 ; for measuring or testing A61B; materials for catheters A61L29/00
• CPC Class Codes: A61M 25/0082 : Catheter tip comprising a tool
• CPC Class Codes: Y10T 29/49124 : On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

An electrical conductor, such as a wire or catheter, which is coated circumferentially with a ferromagnetic material in a selected region, is fed from a high frequency alternating current source. The ferromagnetic material has a quick response in heating and cooling to the controllable power delivery. The ferromagnetic material can be used for separating tissue, coagulation, tissue destruction or achieving other desired tissue effects in numerous surgical procedures.

Claims

1. A thermally adjustable surgical instrument comprising:

an endoscope comprising;

a first channel for receiving a catheter; and

a light source;

a catheter having a conductive loop contained within the catheter comprising a ferromagnetic coating comprising an electrically conductive material covering a portion of the conductive loop, the ferromagnetic coating is sufficiently thin that the ferromagnetic coating will not fracture when the ferromagnetic coating is heated in air and then immersed in liquid while the ferromagnetic coating is heated; and

a power source for delivering an oscillating current to the conductive loop to generate heat in the ferromagnetic coating.

2. The thermally adjustable surgical instrument of claim 1, wherein the ferromagnetic coating 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.

3. The thermally adjustable surgical instrument of claim 1, wherein the endoscope further comprises a second channel for insufflation, aspiration or irrigation.

4. The thermally adjustable surgical instrument of claim 1, wherein the ferromagnetic coating has a thickness between about 0.5 micrometers and about 500 micrometers.

5. The thermally adjustable surgical instrument of claim 1, and wherein the ferromagnetic coating has a thickness between about 1 micrometer and about 50 micrometers and is less than one fifth as thick as the conductor.

6. The thermally adjustable surgical instrument of claim 1, wherein the conductive loop extends from a position before the ferromagnetic coating, through the ferromagnetic coating and to a position beyond the ferromagnetic coating.

7. A thermally adjustable surgical instrument comprising:

an applicator configured to be received in an endoscope channel;

a conductor at least partially disposed within the applicator, the conductor forming a loop at a distal end, a first proximal end for receiving electrical energy from a power supply, and a second proximal end for allowing electrical energy to return to the power supply; and

an electrically conductive ferromagnetic material covering a section of the loop such that the electrically conductive ferromagnetic material forms a heating region along the section of the loop and wherein the electrically conductive ferromagnetic material is sufficiently thin to not fracture when exposed to a temperature differential sufficiently large to cause a ferrite bead to fracture;

wherein the conductor is extendable from the applicator to a position where the heating region and a portion of the conductor not covered by the electrically conductive ferromagnetic material is located outside of the applicator.

8. The thermally adjustable surgical instrument of claim 7, further comprising a non-stick coating covering the heating region.

9. The thermally adjustable surgical instrument of claim 7, further comprising a power source connected to the electrical conductor independent of the electrically conductive ferromagnetic material.

10. The thermally adjustable surgical instrument of claim 9, wherein the conductor and the electrically conductive ferromagnetic material are configured such that substantially all the electrical energy delivered to the conductor flows through the conductor and returns to the power supply without passing a substantial amount of the electrical energy through a tissue.

11. The thermally adjustable surgical instrument of claim 7, wherein in the conductor is a small diameter wire conductor.

12. The thermally adjustable surgical instrument of claim 7, wherein the electrically conductive ferromagnetic material is plated on the conductor.

13. The thermally adjustable surgical instrument of claim 7, wherein the heating region is heatable to a temperature sufficient to cause carbonizing or vaporizing of tissue debris so as to facilitate self-cleaning of the heating region.

14. The thermally adjustable surgical instrument of claim 7, wherein the electrically conductive ferromagnetic material is selected from the group of NiFe alloy, NIRON™

, Co, Fe, FeOFe₂O₃, NiOFe₂O₃, CuOFe₂O₃, MgOFe₂O₃, MnBi, Ni, MnSb, MnOFe₂O₃, Y₃Fe₅O₁₂, CrO₂, MnAs, Gd, Dy, EuO, magnetite, PERMALLOY™

, yttrium iron garnet, aluminum, and zinc.

15. The thermally adjustable surgical instrument of claim 7, wherein the section of the loop is symmetrically covered by the electrically conductive ferromagnetic material.

16. The thermally adjustable surgical tool of claim 7, wherein the section of the loop is asymmetrically covered by the electrically conductive ferromagnetic material.

17. The thermally adjustable surgical instrument of claim 7, further comprising an insulator disposed between the conductor and the electrically conductive ferromagnetic material.

18. A thermal surgical instrument comprising:

a catheter configured to be received in a channel of an endoscope;

a 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 conductor forming the loop so as to form a substantially semi-circular ferromagnetic coating along the loop wherein the ferromagnetic coating is thinner than the conductor and will not fracture when repeatedly heated and immersed in liquid while heated;

wherein the two arms extend from or are configured to be extendable from the catheter, and wherein the arms are not covered by the ferromagnetic coating; and

wherein delivering electrical energy to the conductor causes the ferromagnetic coating to heat to a temperature of at least 58 degrees Centigrade without passing a substantial amount of the electrical energy into tissue contacted by the ferromagnetic coating.

19. A thermally adjustable surgical instrument comprising:

a small diameter wire conductor at least partially disposed in a catheter configured to be received in a channel of an endoscope, the small diameter wire conductor having a proximal end and a distal end, wherein the proximal end is connected to an electrical circuit providing radiofrequency energy and the distal end is deployable from the catheter;

a thin plating of electrically conductive ferromagnetic material covering the distal end of the small diameter wire conductor such that passing radiofrequency energy through the small diameter wire conductor causes the thin plating of electrically conductive ferromagnetic material to heat to at least 58 degrees Centigrade, the thin plating of electrically conductive ferromagnetic material having a thickness and the small diameter wire conductor having a thickness, the thickness of the thin plating of electrically conductive ferromagnetic material being up to about 20 percent of the thickness of the small diameter wire conductor and being movable between air and liquid while heated without fracturing; and

a material disposed over the thin plating of electrically conductive ferromagnetic material for substantially preventing the distal end from sticking to a tissue that is contacted by the thin plating of electrically conductive ferromagnetic material.

20. The thermally adjustable surgical instrument of claim 19, wherein the small diameter wire conductor is about 0.375 millimeters in diameter and wherein the thickness of the thin plating of electrically conductive ferromagnetic material is about 0.05 millimeters or smaller.

21. The thermally adjustable surgical instrument of claim 19, wherein the thickness of the thin plating of electrically conductive ferromagnetic material is between about 0.5 micrometers and about 500 micrometers.

22. The thermally adjustable surgical instrument of claim 19, wherein the thickness of the thin plating of electrically conductive ferromagnetic material is between about 1 micrometer and about 50 micrometers.

23. The thermally adjustable surgical instrument of claim 19, wherein the small diameter wire conductor is between about 0.01 millimeter and 1 millimeter thick.

24. The thermally adjustable surgical instrument of claim 19, wherein the small diameter wire conductor is between about 0.125 millimeters and about 0.5 millimeters thick.

25. The thermally adjustable surgical instrument of claim 19, wherein the thin plating of electrically conductive ferromagnetic material is between about 0.1 percent and about 20 percent as thick as the small diameter wire conductor.

26. The thermally adjustable surgical instrument of claim 19, wherein the small diameter wire conductor extends from a position before the thin plating of electrically conductive ferromagnetic material and to a position beyond the thin plating of electrically conductive ferromagnetic material.

27. A thermally adjustable surgical instrument comprising:

an applicator configured to be received in an endoscope channel;

a conductor at least partially disposed within the applicator, the conductor forming a loop at a distal end, a first proximal end for receiving electrical energy from a power supply, and a second proximal end for allowing the electrical energy to return to the power supply, the conductor having a thickness between 0.01 millimeter and 1 millimeter; and

an electrically conductive ferromagnetic material covering a section of the loop such that the electrically conductive ferromagnetic material forms a heating region along the section of the loop wherein the electrically conductive ferromagnetic material is between 0.05 micrometer and 500 micrometers thick and does not fracture when heated in air and then immersed in liquid; and

wherein the conductor is extendable from the applicator to a position where the heating region and a portion of the conductor not covered by the electrically conductive ferromagnetic material is located outside of the applicator.

28. The thermally adjustable surgical instrument of claim 27, wherein the electrically conductive ferromagnetic material has a thickness between about 1 micrometer and about 50 micrometers.

29. The thermally adjustable surgical instrument of claim 27, wherein the conductor is at least 5 times as thick as the electrically conductive ferromagnetic material.