Electrosurgical system employing multiple electrodes and method thereof

• US 20080021448A1
• Filed: 09/26/2007
• Published: 01/24/2008
• Est. Priority Date: 10/08/2004
• Status: Active Grant

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Covidien AG (Medtronic Plc)
• Inventors: McPherson, James, Orszulak, James
• Granted Patent: US 8,182,477 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/124 switching the output to different electrodes, e.g. sequentially
• CPC Class Codes: A61B 2018/143 multiple needles

Abstract

A system for heat ablation of tissue in a patient comprises a plurality of electrodes operatively connected to a source of radiofrequency energy and configured to apply RF energy to tissue at a patient site, a plurality of RF current restricting circuits, each circuit coupled between one of the plurality of electrodes and the source of radiofrequency energy, and configured to restrict RF energy to the electrode when the current restricting circuit is enabled and not restrict RF energy to flow to the electrode when the current restricting circuit is disabled, at least one return electrode adapted to contact the patient and configured to return RF energy to the RF source; and a switching mechanism configured to selectively enable each of the plurality of RF current restricting circuits, in one of a sequential and non sequential fashion, wherein the switching mechanism is isolated from each of the current restricting circuits.

Claims

1-6. -6. (canceled)

7. A system for heat ablation of tissue in a patient, the system comprising:

at least one electrode operatively connected to a source of electrosurgical energy, the at least one electrode configured to apply electrosurgical energy to the tissue of the patient;

at least one return electrode adapted to contact the patient and configured to return electrosurgical energy to the source of electrosurgical energy; and

a current restricting circuit coupled between the at least one electrode and the source of electrosurgical energy, the current restricting circuit configured to restrict a flow of electrosurgical energy to the at least one electrode when the current restricting circuit is enabled and to not restrict the flow of electrosurgical energy to the at least one electrode when the current restricting circuit is disabled.

8. The system as in claim 7, wherein the current restricting circuit comprises:

a switch configured to direct the flow of electrosurgical energy; and

a plurality of current restrictive devices arranged to restrict the flow of electrosurgical energy when the switch is disposed in a first position and not restrict the flow of electrosurgical energy when the switch is disposed in a second position.

9. The system as in claim 8, wherein the plurality of current restrictive devices includes diodes.

10. The system as in claim 9, wherein a plurality of the diodes is arranged in an H-Bridge arrangement wherein the switch is disposed between adjacent diodes, and wherein electrosurgical energy is conducted when the switch is closed.

11. The system as in claim 8, wherein the switch is a transistor.

12. A system for regulating a flow of electrosurgical energy, the system comprising:

a current restricting circuit operatively coupled between a source of electrosurgical energy and an electrode, the current restricting circuit including;

a switch configured to direct the flow of electrosurgical energy; and

a plurality of current restrictive devices arranged in an H-Bridge arrangement, wherein the switch is disposed between adjacent current restrictive devices of the plurality of current restrictive devices;

wherein the current restricting circuit is configured to restrict a flow of electrosurgical energy when the switch is in a first position and not restrict the flow of electrosurgical energy when the switch is in a second position; and

wherein the current restricting circuit dynamically controls the electrosurgical energy delivered to the electrode.

13. The system as in claim 12, further comprising a controller for dynamically controlling a duty cycle of the electrosurgical energy.

14. The system as in claim 12, wherein the plurality of current restrictive devices includes a diode.

15. The system as in claim 12, wherein the switch is a transistor.

16. A current restricting circuit for controlling the delivery of electrosurgical energy, the circuit comprising:

a switch configured to direct a flow of electrosurgical energy between a source of electrosurgical energy and an electrosurgical energy delivery device;

a first current restricting device, disposed between the switch and the source of electrosurgical energy;

a second current restricting device, disposed between the switch and the electrosurgical energy delivery device;

a third current restricting device, disposed between the switch and the source of electrosurgical energy and in parallel with the first current restricting device; and

a fourth current restricting device, disposed between the switch and the electrosurgical energy delivery device and in parallel with the second current restricting device; and

wherein the first and fourth current restricting devices conduct current in a forward direction, the second and third current restricting devices conduct current in a forward direction.

17. The circuit as in claim 16, wherein the circuit is configured to provide dynamic control of the flow of electrosurgical energy to the electrosurgical energy delivery device.

18. The circuit as in claim 16, wherein the first, second, third and fourth current restricting devices include diodes.

19. The circuit as in claim 16, wherein the switch is a transistor.