Polyphase electrosurgical system and method

• US 9,700,366 B2
• Filed: 08/01/2008
• Issued: 07/11/2017
• Est. Priority Date: 08/01/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Paulus, Joseph A.
• Primary Examiner(s): GIULIANI, THOMAS ANTHONY
• Application Number:
  US12/184,556
• Publication Number:
  US 20100030210A1
• Time in Patent Office: 3,266 Days
• Field of Search: 606 33- 34, 600393, 607 98, 607 99, 607102
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 2018/00654 with individual control of each of a plurality of energy emitting elements
• CPC Class Codes: A61B 2018/00684 using lookup tables
• CPC Class Codes: A61B 2018/00732 Frequency
• CPC Class Codes: A61B 2018/0075 Phase
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/128 generating two or more frequencies
• CPC Class Codes: A61B 2018/143 multiple needles

Abstract

A polyphase electrosurgical system and method are provided. In embodiments, a radiofrequency generator having the capability of delivering a plurality of independent electrosurgical signals is disclosed. An electrosurgical instrument having an array of electrodes that correspond to the plurality of signals may be used to deliver the electrosurgical signals to tissue. In embodiments, three RF signals having a phase offset of about 120° therebetween, i.e., a three-phase configuration, may be used to achieve a balanced delivery of electrosurgical energy, which may lead to increased rates of energy delivery, improved control of tissue ablation regions, and improved operative outcomes. The phase, amplitude, and/or frequency of each signal may be independently variable in response to user inputs and/or biological parameters such as tissue impedance or return electrode current.

Claims

1. A polyphase electrosurgical system, comprising:

a storage device configured to store digitized waveform data;

an energy module including three digital to analog converters and three amplifiers, each digital to analog converter configured to receive the digitized waveform data, convert the digitized waveform data to a respective radiofrequency signal, and deliver the respective radiofrequency signal to a respective amplifier of the three amplifiers, wherein;

each respective radiofrequency signal has a phase offset relative to the other radiofrequency signals,

each of the three amplifiers amplifies the respective radiofrequency signal and provides the respective radiofrequency signal to a respective output of the energy module, and

the energy module is configured to adjust a frequency of each of the radiofrequency signals by altering a rate at which the digitized waveform data is converted by the digital to analog converters;

an electrosurgical instrument having a housing and three distinct active electrodes extending externally from a distal end of the housing and disposed in spaced relation relative to each other, each distinct active electrode operably coupled to one of the respective outputs of the energy module, wherein each of the respective outputs is configured to deliver one of the provided respective radiofrequency signals to the respective distinct active electrode, each of the three distinct active electrodes defining an elongate shaft having a tapered distal tip configured to penetrate tissue;

a tissue impedance sensor operatively coupled to at least one of the three distinct active electrodes and in communication with the energy module, the energy module configured to adjust the rate at which the digitized waveform data is converted by the digital to analog converters in response to a signal from the tissue impedance sensor;

a return electrode operably coupled to the energy module and disposed in spaced relation to the electrosurgical instrument; and

an actuator operably coupled to the energy module for activating the energy module.

2. The polyphase electrosurgical system of claim 1, wherein the phase offset is selected from the group consisting of about 120 degrees, about 90 degrees, and in the range of about 1 degree to about 180 degrees.

3. The polyphase electrosurgical system of claim 1, further comprising:

a set of programmable instructions stored in the storage device for generating the radiofrequency signals; and

a processor operably coupled to the storage device, the processor configured to execute the set of programmable instructions.

4. The polyphase electrosurgical system of claim 3, wherein the digitized waveform data is organized in a table, the table including:

a first data point corresponding to a phase of a first sample radiofrequency signal; and

a second data point corresponding to a phase of a second sample radiofrequency signal.

5. The polyphase electrosurgical system of claim 3, wherein the set of programmable instructions is configured to vary an amplitude of at least one of the radiofrequency signals.

6. The polyphase electrosurgical system of claim 3, wherein the set of programmable instructions is configured to vary a frequency of at least one of the radiofrequency signals.

7. The polyphase electrosurgical system of claim 3, further comprising a display module operably coupled to the processor for displaying operational parameters of the energy module.

8. The polyphase electrosurgical system of claim 1, wherein the actuator is selected from the group consisting of a handswitch and a footswitch.

9. The polyphase electrosurgical system of claim 1, wherein the energy module is configured to adjust at least one of the phase offset or an amplitude of at least one of the respective radiofrequency signals to minimize a target return electrode current.

10. The polyphase electrosurgical system of claim 1, wherein the distal end of the housing defines a planar surface perpendicular to a longitudinal axis defined by the housing and the three distinct active electrodes extend from the planar surface.

11. The polyphase electrosurgical system of claim 1, wherein the energy module is configured to:

adjust the frequency of each of the radiofrequency signals by altering a rate at which the digitized waveform data is delivered to the digital to analog

converters.

12. A polyphase electrosurgical system, comprising:

a storage device configured to store digitized waveform data;

an energy module including three digital to analog converters and three amplifiers, each digital to analog converter configured to receive the digitized waveform data, convert the digitized waveform data to a respective radiofrequency signal, and deliver the respective radiofrequency signal to a respective amplifier of the three amplifiers, wherein;

each respective radiofrequency signal has a phase offset relative to the other radiofrequency signals,

each of the three amplifiers amplifies the respective radiofrequency signal and provides the respective radiofrequency signal to a respective output of the energy module, and

the energy module is configured to adjust a frequency of each of the radiofrequency signals by altering a rate at which the digitized waveform data is converted by the digital to analog converters;

an electrosurgical instrument having a housing and three distinct active electrodes extending externally from a distal end of the housing and disposed in spaced relation relative to each other, each distinct active electrode operably coupled to one of the respective outputs of the energy module, wherein each of the respective outputs is capable of delivering the provided respective radiofrequency signals to the respective distinct active electrode, each of the three distinct active electrodes defining an elongate shaft having a tapered distal tip configured to penetrate tissue; and

a return electrode operably coupled to the energy module and disposed in spaced relation to the electrosurgical instrument.

13. The polyphase electrosurgical system of claim 12, wherein the energy module is configured to adjust at least one of the phase offset or an amplitude of at least one of the radiofrequency signals.

14. The polyphase electrosurgical system of claim 12, wherein the distal end of the housing defines a planar surface perpendicular to a longitudinal axis defined by the housing and the three distinct active electrodes extend from the planar surface.

15. The polyphase electrosurgical system of claim 12, wherein the energy module is configured to:

adjust the frequency of each of the radiofrequency signals by altering a rate at which the digitized waveform data is delivered to the digital to analog

converters.

16. A polyphase electrosurgical system, comprising:

a storage device configured to store digitized waveform data;

an energy module including a plurality of digital to analog converters and an amplifier corresponding to each of the plurality of digital to analog converters, each digital to analog converter configured to receive the digitized waveform data, convert the digitized waveform data to a respective radiofrequency signal, and deliver the respective radiofrequency signal to the corresponding amplifier, wherein;

each respective radiofrequency signal has a phase offset relative to the other radiofrequency signals,

each amplifier amplifies the respective radiofrequency signal and provides the respective radiofrequency signal to a respective output of the energy module, and

the energy module is configured to adjust a frequency of each of the radiofrequency signals by altering a rate at which the digitized waveform data is converted by the digital to analog converters; and

an electrosurgical instrument having a housing and three distinct active electrodes extending externally from a distal end of the housing and disposed in spaced relation relative to each other, each distinct active electrode operably coupled to one of the respective outputs of the energy module, wherein each of the respective outputs is capable of delivering one of the provided respective radiofrequency signals to the respective distinct active electrode, each of the three distinct active electrodes defining an elongate shaft having a tapered distal tip configured to penetrate tissue.

17. The polyphase electrosurgical system of claim 16, wherein the energy module is configured to:

adjust the frequency of each of the radiofrequency signals by altering a rate at which the digitized waveform data is delivered to the digital to analog

converters.