Adjustable impedance electrosurgical electrodes

• US 20080281316A1
• Filed: 05/10/2007
• Published: 11/13/2008
• Est. Priority Date: 05/10/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Odom, Darren, Carlton, John
• Granted Patent: US 8,777,941 B2
• Time in Patent Office: Days
• US Class Current: 606/40
• CPC Class Codes: A61B 18/1206 Generators therefor
• 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 18/16 Indifferent or passive electrodes for grounding
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61B 2018/128 generating two or more frequencies
• CPC Class Codes: A61B 2018/147 Electrodes transferring energy by capacitive coupling, i.e. with a dielectricum between electrode and target tissue
• CPC Class Codes: A61B 2018/167 Passive electrodes capacitively coupled to the skin

Abstract

An electrosurgical system is disclosed. The electrosurgical system includes at least one electrosurgical electrode having a resistive element and a capacitive element configured in series. The electrosurgical system also including an electrosurgical generator configured to generate electrosurgical energy having a first frequency which generates a first impedance in the at least one electrode due to capacitive reactance of the capacitive element in series. The generator is further configured to adjust the first frequency to at least one other frequency to generate a different impedance in the at least one electrode due to capacitive reactance of the capacitive element in series, thereby adjusting the temperature of at least one electrosurgical electrode.

Claims

1. An electrosurgical system, comprising:

at least one electrosurgical electrode having a resistive element and a capacitive element configured in series; and

an electrosurgical generator configured to generate electrosurgical energy having a first frequency that generates a first impedance in the at least one electrode due to capacitive reactance of the capacitive element in series, the generator being further configured to adjust the first frequency to at least one other frequency to generate a different impedance in the at least one electrode due to capacitive reactance of the capacitive element in series, thereby adjusting the temperature of at least one electrosurgical electrode.

2. An electrosurgical system according to claim 1, wherein the first frequency is less than the at least one other frequency and the first corresponding impedance is higher than the second corresponding impedance.

3. An electrosurgical system according to claim 1, wherein the capacitive element is a capacitive layer.

4. An electrosurgical system according to claim 3, wherein the capacitive layer is disposed on an outer conductive surface of the at least one electrosurgical electrode.

5. An electrosurgical system according to claim 3, wherein the capacitive layer is disposed on an innermost conductive surface of the at least one electrosurgical electrode.

6. An electrosurgical system according to claim 1, wherein the frequency of the energy is inversely proportional to the amount of heat being generated by the at least one electrosurgical electrode.

7. An electrosurgical system according to claim 1, wherein the capacitive element is selected from the group consisting of aluminum, titanium dioxide, titanium oxide, tantalum oxide, aluminum oxide, and barium titranate.

9. An electrosurgical system according to claim 7, wherein the capacitive element is disposed on an outer conductive surface of each sealing plate.

10. An electrosurgical system according to claim 7, wherein the capacitive element is disposed on an innermost conductive surface of each sealing plate.

11. An electrosurgical system according to claim 7, wherein the frequency of the energy is inversely proportional to the amount of heat being generated by the at least one electrosurgical electrode.

12. An electrosurgical system according to claim 7, wherein the capacitive element is selected from the group consisting of aluminum, titanium dioxide, titanium oxide, tantalum oxide, aluminum oxide, and barium titranate.

14. A method for performing electrosurgical procedures according to claim 11, further comprising the step of:

lowering the first frequency to at least one other frequency to increase the temperature of the least one electrosurgical electrode.

15. A method for performing electrosurgical procedures according to claim 11, further comprising the step of:

increasing the first frequency to at least one other frequency to decrease the temperature of the least one electrosurgical electrode.

8. An electrosurgical system, comprising:

an electrosurgical forceps for sealing tissue including at least one shaft member having an end effector assembly disposed at a distal end thereof, the end effector assembly including jaw members movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members cooperate to grasp tissue therebetween, wherein each of the jaw members includes a sealing plate that communicates electrosurgical energy through tissue held therebetween, each of the sealing plates having a resistive element and a capacitive element configured in series; and

an electrosurgical generator configured to generate electrosurgical energy having a first frequency that generates a first impedance in at least one of the sealing plates due to capacitive reactance of the capacitive element in series, the generator being further configured to adjust the first frequency to at least one other frequency to generate a different impedance in at least one of the sealing plates due to capacitive reactance of the capacitive element in series, thereby adjusting the temperature of at least one of the sealing plates.

13. A method for performing electrosurgical procedures, comprising the steps of:

providing at least one electrosurgical electrode having a resistive element and a capacitive element configured in series;

generating electrosurgical energy having a first frequency that generates a first impedance in the at least one electrode due to capacitive reactance of the capacitive element in series; and

adjusting the first frequency to at least one other frequency to generate a different impedance in the at least one electrode due to capacitive reactance of the capacitive element in series.