Soft tissue heating apparatus with independent, cooperative heating sources

• US 6,358,273 B1
• Filed: 04/09/1999
• Issued: 03/19/2002
• Est. Priority Date: 04/09/1999
• Status: Expired due to Term

• Current Assignee: Oratec Interventions Incorporated (Smith & Nephew PLC)
• Original Assignee: Oratec Interventions Incorporated (Smith & Nephew PLC)
• Inventors: Stewart, Daren L., Sharkey, Hugh R., Strul, Bruno
• Primary Examiner(s): GIBSON, ROY DEAN
• Application Number:
  US09/289,459
• Time in Patent Office: 1,075 Days
• Field of Search: 607/96, 607/101, 607/102, 607/103, 607/104, 607/105, 607/116, 607/115, 606/41-42, 606/45, 606/49, 606/27-29, 606/31
• US Class Current: 607/96
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• 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 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00714 Temperature
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00815 measured by a thermistor
• CPC Class Codes: A61B 2018/1253 monopolar

Abstract

A medical probe for the heating of soft tissue, such as collagen tissue, wherein the medical probe has an elongated body with a proximal and distal end, a heating source, an RF electrode. Optional components include a thermocouple, and an insulative sleeve. The probe'"'"'s elongated body is preferably hollow and flexible. The RF electrode and the heating source are powered by independently controlled power sources and cooperate to maintain a constant and smooth temperature to the distal end of the RF electrode. The heating source may be a contained liquid, such as saline, or an electrothermal mass, such as a ferrite, a toroid, a resistive element, or the like. Current induced from the conductor to the heating source creates heat in the heating source. The thermocouple measures the temperature of the heating source and adjusts the power to the conductor to maintain the heating source'"'"'s temperature.

Claims

1. A tissue heating apparatus, comprising:

an elongated body having proximal and distal ends;

a first heating source disposed on the distal end of said elongated body to deliver heat to a tissue to be treated; and

a second heating source disposed adjacent said first heating source to provide secondary heat to the tissue simultaneously as said first heating source delivers heat to the tissue;

wherein said first heating source provides a more rapid thermal response than said second heating source and said second heating source has a higher heat capacity than said first heating source such that temperature fluctuations in said first heating source are dampened by said second heating source, and wherein said second heating source comprises an electrothermal mass.

2. The tissue heating apparatus of claim 1, wherein said electrothermal mass comprises a cylindrically shaped ferrite bead having at least one longitudinal opening spanning the length of said ferrite bead.

3. The tissue heating apparatus of claim 1, wherein said electrothermal mass comprises a toroid having annular shape.

4. The tissue heating apparatus of claim 1, wherein said electrothermal mass comprises a resistive element.

5. The tissue heating apparatus of claim 1, wherein said electrothernal mass comprises a liquid disposed within a sealed container.

6. The tissue heating apparatus of claim 1, wherein said electrothermal mass source comprises a coil.

7. The apparatus of claim 6, further comprising an additional electrothermal mass positioned within said coil.

8. The apparatus of claim 1, wherein said second heating source comprises a heated liquid circulated through said distal end.

9. The apparatus of claim 1, wherein said first heating source comprises an RF electrode disposed on the distal end of said body.

10. The apparatus of claim 1, further comprising a first thermocouple disposed within said elongated body to sense the temperature of the second heating source.

11. The tissue heating apparatus of claim 10, further comprising:

a second thermocouple, said second thermocouple located proximally behind said first heating source, such that said second thermocouple primarily responds according to the temperature of said first heating source.

12. A tissue heating apparatus, comprising:

an elongated body having proximal and distal ends;

a first heating source disposed on the distal end of said elongated body to deliver heat to a tissue to be treated;

a second heating source disposed adjacent said first heating source to provide secondary heat to said first heating source; and

a conductor having a portion adjacent to said second heating source such that said conductor induces a current into said second heating source when power is applied to the conductor;

wherein said first heating source provides a more rapid thermal response that said second heating source and said second heating source has a higher heat capacity than said first heating source such that temperature fluctuations in said first heating source are dampened by said second heating source.

13. A tissue heating apparatus, comprising:

an elongated body having proximal and distal ends;

a first heating source disposed on the distal end of said elongated body to deliver heat to a tissue to be treated;

a second heating source disposed adjacent said first heating source to provide secondary heat to said first heating source; and

a conductive paste, disposed within the distal end of said tissue heating apparatus to facilitate an even distribution of heat between said second heating source and said first heating source;

wherein said first heating source provides a more rapid thermal response than said second heating source and said second heating source has a higher heat capacity than said first heating source such that temperature fluctuations in said first heating source are dampened by said second heating source.

14. A tissue heating apparatus, comprising:

an elongated body having proximal and distal ends;

a first heating source disposed within the distal end of said elongated body to deliver heat to a tissue to be treated; and

a second heating source disposed within said elongated body proximally behind said first heating source to provide secondary heat to said first heating source wherein said first heating source provides a more rapid thermal response than said second heating source and said second heating source has a higher heat capacity than said first heating source such that temperature fluctuations in said first heating source are dampened by said second heating source, wherein said elongated body defines a hollow distal end with a heat conductive paste being disposed with said distal end in contact with said first and second heating sources.

15. The tissue heating apparatus of claim 14, wherein said first heating source comprises an RF electrode.

16. A tissue heating apparatus, comprising:

an elongated body having proximal and distal ends;

a first heating source disposed on the distal end of said elongated body to deliver heat to a tissue to be treated; and

a second heating source disposed within said elongated body proximally behind said first heating source to provide secondary heat to said first heating source wherein said first heating source provides a more rapid thermal response than said second heating source and said second heating source has a higher heat capacity than said first heating source such that temperature fluctuations in said first heating source are dampened by said second heating source, wherein said second heating source comprises an electrothermal mass with a conductor passing in close proximity thereto so as to induce a current in said mass in response to power applied to said conductor.

17. The apparatus according to claim 16, wherein said electrothermal mass comprises a ferrite cylinder with said conductor passing through an opening therein.

18. A soft tissue heating apparatus, comprising:

an elongated body with proximal and distal ends;

an RF electrode disposed on the distal end of said elongated body to deliver heat to a tissue to be treated;

a separate heating source disposed within said distal end proximally behind said RF electrode to provide secondary heat to said RF electrode, said heating source comprising a ferrite mass; and

a conductor positioned in close proximity to said ferrite mass to induce a heating current therein in response to applied power.