Ablation Systems, Probes, and Methods for Reducing Radiation from an Ablation Probe into the Environment

• US 20130178841A1
• Filed: 01/05/2012
• Published: 07/11/2013
• Est. Priority Date: 01/05/2012
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Vivant Medical, Inc. (Johnson Controls International plc)
• Inventors: Reid, William O. Jr.
• Granted Patent: US 9,375,274 B2
• Time in Patent Office: Days
• US Class Current: 606/33
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00017 with gas
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00077 high, i.e. electrically conducting
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00458 Deeper parts of the skin, e.g. treatment of vascular disorders or port wine stains
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00809 measured thermochromatically
• CPC Class Codes: A61B 2018/1425 Needle
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 2018/1838 Dipole antennas
• CPC Class Codes: A61B 2018/1869 with an instrument interstitially inserted into the body, e.g. needles
• CPC Class Codes: A61B 2018/1892 Details of electrical isolations of the antenna
• CPC Class Codes: A61B 2090/0481 against EM radiation, e.g. microwave
• CPC Class Codes: A61B 90/04 Protection of tissue around surgical sites against effects of non-mechanical surgery, e.g. laser surgery protection of eyes against laser radiation A61F9/022

Abstract

The ablation systems, ablation probes, and corresponding methods according to the present disclosure reduce or eliminate energy radiating from an ablation probe into the environment. Some ablation probes include a retractable sheath that shields at least the radiating portion of the ablation probe. The retractable sheath and/or the ablation probe may include conduits through which a fluid may flow to shield the radiating portion and to drive the retractable sheath to an extended state. Other ablation probes include apertures defined in the probe walls through which the fluid can flow to expand a balloon surrounding the radiating portion. Yet other ablation probes include a thermal indicator to indicate the temperature of the ablation probe to a user. The ablation systems include fluid circuits and associated mechanical controls for varying the contents and/or flow rate of the fluid provided to the radiating portion of the ablation probe.

Claims

1. An ablation probe, comprising:

a shaft having a proximal portion and a distal portion, the distal portion comprising a radiating portion configured to deliver energy to tissue; and

a retractable sheath surrounding at least the radiating portion of the shaft, the retractable sheath configured to prevent at least a portion of the energy from radiating outside of the retractable sheath, the retractable sheath configured to retract as the shaft is inserted into tissue.

2. The ablation probe according to claim 1, wherein the distal portion of the shaft includes a sharp tip and the retractable sheath includes a tip cover coupled to a distal end of the retractable sheath, the tip cover configured to enclose the sharp tip when the retractable sheath is in an extended state.

3. The ablation probe according to claim 1, further comprising a handle coupled to a proximal end of the shaft, the retractable sheath coupled to a distal end of the handle.

4. The ablation probe according to claim 1, wherein the retractable sheath is a compressible plastic cylinder and at least a portion of the compressible plastic cylinder is coated with an electrically conductive material.

5. The ablation probe according to claim 1, wherein the retractable sheath is electrically coupled to an electrical ground.

6. The ablation probe according to claim 1, wherein the retractable sheath is a compressible, electrically conductive material formed in the shape of a cylinder.

7. The ablation probe according to claim 6, wherein the compressible, electrically conductive material is a metal.

8. The ablation probe according to claim 7, wherein the metal is copper.

9. The ablation probe according to claim 1, wherein the retractable sheath includes at least one fluid conduit configured to surround the shaft.

10. The ablation probe according to claim 9, wherein the retractable sheath includes an inner wall and an outer wall, and wherein the at least one fluid conduit is disposed between the inner and outer wall.

11. The ablation probe according to claim 10, wherein the outer wall of the retractable sheath is coated with an electrically conductive material.

12. An ablation system, comprising:

an ablation probe including;

a shaft having a proximal portion and a distal portion, the distal portion including an antenna configured to deliver energy to tissue; and

a sheath surrounding at least the radiating portion of the shaft, the sheath including at least one fluid conduit defined therein;

a fluid source in fluid communication with the at least one fluid conduit;

a fluid pump in fluid communication with the fluid source and the at least one fluid conduit, the fluid pump configured to pump a fluid through the at least one fluid conduit; and

a generator electrically coupled to the antenna, the generator configured to supply electrical energy to the antenna.

13. The ablation system according to claim 12, wherein the fluid has dielectric properties that reduce the energy radiating from the radiating portion of the shaft.

14. The ablation system according to claim 12, wherein the fluid is selected from the group consisting of air, a mixture of cooling fluid and air, and a mixture of cooling fluid and a dielectric material.

15. The ablation system according to claim 12, wherein the energy is microwave energy.

16. The ablation system according to claim 12, wherein the sheath is a retractable sheath configured to retract when the shaft is inserted in tissue.

17. The ablation system according to claim 16, wherein the fluid pump is configured to supply a fluid to the at least one fluid conduit under a working pressure sufficient to extend the retractable sheath as the shaft is removed from tissue.

18. A method of operating an ablation probe to reduce radiation of energy from the ablation probe to a surrounding surgical environment:

retracting a sheath surrounding at least a radiating portion of an ablation probe, the sheath retracting along a longitudinal axis of the ablation probe toward a proximal end of the ablation probe as the radiating portion of the ablation probe is advanced towards a target volume of tissue; and

advancing the sheath along the longitudinal axis of the ablation probe toward a distal end of the probe as the radiating portion of the ablation probe is removed from tissue such that the sheath surrounds at least the radiating portion of the ablation probe.

19. The method according to claim 18, further comprising pumping a fluid into at least one fluid conduit disposed in the sheath, the fluid having properties that at least reduce the energy radiating from the radiating portion of the ablation probe to the environment.

20. The method according to claim 19, wherein the fluid is selected from the group consisting of nitrogen and air.