Electrosurgical apparatus with high speed energy recovery

• US 8,287,529 B2
• Filed: 09/05/2008
• Issued: 10/16/2012
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Orszulak, James H.
• Primary Examiner(s): KOHARSKI, CHRISTOPHER
• Application Number:
  US12/205,298
• Publication Number:
  US 20100063494A1
• Time in Patent Office: 1,502 Days
• Field of Search: 606/34, 606 37- 40
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2018/00345 Vascular system
• CPC Class Codes: A61B 2018/00404 Blood vessels other than those in or around the heart
• CPC Class Codes: A61B 2018/00619 Welding
• CPC Class Codes: A61B 2018/0063 Sealing
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/00892 Voltage

Abstract

A circuit for controlling the discharging of stored energy in an electrosurgical generator includes a pulse modulator which controls an output of a power supply. At least one comparator is configured to provide an error signal to the pulse modulator based on a comparison between an output signal generated by the power supply and a feedback signal generated in response to the application of energy to tissue. A discharge circuit is configured to control the discharge of the output of the power supply to an inductive load disposed in parallel with the output of the power supply based on the comparison between the output signal and the feedback signal. The discharge circuit provides a rapid response and time rate control of the delivered electrosurgical energy by controlling the power supply and delivered RF energy in real time, based on a feedback signal generated in response to the application of energy to tissue.

Claims

1. A method for providing treatment energy from a generator to tissue, comprising the steps of:

storing direct current energy in an output filter in operable communication with an output stage;

converting the stored direct current energy into treatment energy at the output stage;

controlling an output of the treatment energy for treating tissue;

sensing at least one sensed tissue property based on application of the treatment energy to tissue; and

controlling a time rate of change of a discharge of the stored direct current energy away from the output stage based on a comparison between the stored direct current energy and a feedback signal based on the sensed tissue property.

2. A method for providing treatment energy from a generator to tissue according to claim 1, wherein the at least one sensed tissue property of the generating step is tissue impedance based on an application of treatment energy to the tissue.

3. A method for providing treatment energy from a generator to tissue according to claim 1, further comprising the step of:

controlling the time rate of change of the discharge of the direct current energy from the output filter to an inductive load in operable communication therewith.

4. A method for providing treatment energy from a generator to tissue according to claim 1, further comprising the step of:

adjusting at least one of a power supply and an output stage to control an amount of treatment energy output by the generator for treatment of tissue.

5. A method for providing treatment energy from a generator to tissue according to claim 1, wherein the treatment energy of the controlling step is RF energy.

6. A method for providing treatment energy from a generator to tissue according to claim 1, further comprising the step of:

providing a discharge circuit in operable communication with an output filter to provide the time rate of control of the discharge of the direct current energy stored in the output filter.

7. A method for providing treatment energy from a generator to tissue according to claim 1, further comprising the step of:

Controlling the output of treatment energy in real time.

8. A method for providing treatment energy from a generator to tissue according to claim 1, further comprising the step of:

actuating a switching component based on the comparison between the stored direct current energy and the feedback signal to discharge the stored direct current energy away from the output stage through an inductive load.

9. A method for providing treatment energy from a generator to tissue according to claim 8, further comprising the step of:

controlling the flow of current through the inductive load based on a comparison of a voltage drop across a resistive element disposed in series with the inductive load and a threshold voltage.