Electrosurgical apparatus with high speed energy recovery

• US 8,968,295 B2
• Filed: 09/26/2012
• Issued: 03/03/2015
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Orszulak, James H.
• Primary Examiner(s): Lavert, Nicole F
• Application Number:
  US13/627,136
• Publication Number:
  US 20130023869A1
• Time in Patent Office: 888 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 generator for providing treatment energy to tissue, comprising:

a power supply having an output filter and a discharge circuit, the output filter configured to store and output direct current energy;

an output stage coupled to the power supply and configured to convert the direct current energy into treatment energy for use in treating tissue; and

a controller configured to adjust at least one of the power supply or the output stage to control the amount of treatment energy output by the output stage, wherein the discharge circuit is configured to control a time rate change of a discharge of the direct current energy stored in the output filter away from the output stage based on a comparison between the direct current energy stored in the output filter and a feedback signal generated by application of the treatment energy to tissue.

2. A generator for providing treatment energy to tissue according to claim 1, wherein the feedback signal is based on at least one sensed tissue property.

3. A generator for providing treatment energy to tissue according to claim 2, wherein the at least one sensed tissue property is derived based on an application of treatment energy output by the output stage to tissue.

4. A generator for providing treatment energy to tissue according to claim 2, wherein the at least one sensed tissue property is an increase in tissue impedance based on tissue desiccation.

5. A generator for providing treatment energy to tissue according to claim 1, further comprising a sensor operably coupled to the controller and configured to sense at least one tissue property.

6. A generator for providing treatment energy to tissue according to claim 5, wherein the feedback signal is generated by the sensor based on the at least one sensed tissue property.

7. A generator for providing treatment energy to tissue according to claim 1, wherein the output filter is an LC circuit.

8. A generator for providing treatment energy to tissue according to claim 1, wherein the treatment energy is RF energy.

9. A generator for providing treatment energy to tissue according to claim 1, wherein the controller is configured to adjust at least one of the power supply or the output stage to control the amount of treatment energy output by the output stage in real time.

10. A generator for providing treatment energy to tissue, comprising:

a power supply having an output filter and a discharge circuit, the output filter configured to store and output direct current energy;

an output stage coupled to the power supply and configured to convert the direct current energy into treatment energy for use in treating tissue;

at least one sensor configured to sense at least one tissue property based on the application of treatment energy to tissue and configured to generate a feedback signal based on the at least one sensed tissue property; and

a controller operably coupled to the at least one sensor and configured to adjust at least one of the power supply or the output stage to control the amount of treatment energy output by the output stage, wherein the discharge circuit is configured to provide time rate control of the discharge of the direct current energy stored in the output filter away from the output stage based on a comparison between the direct current energy stored in the output filter and the feedback signal generated by the sensor.