Microwave ablation system with dielectric temperature probe

• US 9,968,401 B2
• Filed: 11/12/2014
• Issued: 05/15/2018
• Est. Priority Date: 12/18/2009
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Manley, Prakash, Brannan, Joseph D.
• Primary Examiner(s): GIULIANI, THOMAS ANTHONY
• Application Number:
  US14/539,326
• Publication Number:
  US 20150073403A1
• Time in Patent Office: 1,280 Days
• Field of Search: 606 33, 606 34, 606 38, 606 41, 606 42
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00648 using more than one sensed parameter
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/1869 with an instrument interstitially inserted into the body, e.g. needles

Abstract

An electromagnetic surgical ablation system having a generator adapted to selectively provide surgical ablation energy to an ablation probe, and methods of operating same, are disclosed. The system includes a controller operatively coupled to the generator, and a tissue sensor probe operatively coupled to the controller. The tissue sensor provides a tissue temperature and at least one tissue dielectric property to the controller. During an electromagnetic tissue ablation procedure, the controller monitors tissue temperature and the at least one tissue dielectric property to determine tissue status, and to activate and deactivate the generator in accordance therewith.

Claims

1. A method of operating an ablation system, comprising:

sensing tissue temperature, tissue permittivity, and tissue loss factor at a tissue sensor probe coupled to a source of ablation energy, the tissue sensor probe being disposed within tissue;

absorbing moisture from the tissue sensor probe using an absorbent sleeve slidably disposed on the tissue sensor probe;

determining a tissue status based on the sensed tissue temperature, the tissue permittivity, and the tissue loss factor; and

applying ablation energy to the tissue based on the determined tissue status.

2. The method according to claim 1, wherein sensing of the tissue permittivity and the tissue loss factor occurs during a sensing phase at which no ablation energy is applied to the tissue.

3. The method according to claim 2, wherein the ablation energy is applied during a treatment phase.

4. The method according to claim 3, further comprising:

adjusting a time period of the treatment phase using a cycle timer.

5. The method according to claim 4, wherein sensing of the tissue temperature occurs during at least one of the sensing phase or the treatment phase.

6. The method according to claim 3, further comprising:

iterating the sensing phase and the treatment phase until the determined tissue status is indicative of a completed ablation.

7. The method according to claim 1, further comprising:

accessing a look-up table stored in a memory associated with the source of ablation energy to determine the tissue status based on the sensed tissue temperature, the tissue permittivity, and the tissue loss factor.

8. The method according to claim 7, wherein the look-up table is a three-dimensional lookup table storing the tissue temperature, the tissue permittivity, and the tissue loss factor as each of the dimensions.