Methods, systems, and devices for performing electrosurgical procedures

• US 8,500,727 B2
• Filed: 05/12/2009
• Issued: 08/06/2013
• Est. Priority Date: 05/13/2008
• Status: Active Grant

• Current Assignee: Megadyne Medical Products Incorporated (Johnson & Johnson)
• Original Assignee: Megadyne Medical Products Incorporated (Johnson & Johnson)
• Inventors: Aramayo, Thomas F.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US12/464,591
• Publication Number:
  US 20100030212A1
• Time in Patent Office: 1,547 Days
• Field of Search: 606 32- 34, 606/41, 606 45- 50
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/1422 Hook
• CPC Class Codes: A61B 2018/1425 Needle

Abstract

An electrosurgical system including a sharpened electrosurgical electrode, which can have a coated surface, and an automatically adjusting electrosurgical wave generator is disclosed. The automatically adjusting wave generator and the sharpened electrode tip provide or enhance the properties, attributes and/or characteristics of the electrosurgical system and prevent tissue damage and reduce incidences of post-operative complications, thereby quickening the healing process. The wave generator detects various circuit parameters and automatically adjusts the output settings, such as the output power level, based on the various circuit parameters, such as tissue impedance, to prevent undesirable tissue damage.

Claims

1. An electrosurgical system comprising:

an electrosurgical electrode adapted to transmit electrical energy to patient tissue during an electrosurgical procedure, the electrode having a configuration that enhances rapid feedback used to automatically correct and regulate power levels applied to the electrode, the electrode comprising a working surface that is sharpened to concentrate the electrical energy transmitted from the electrode to the patient tissue during an electrosurgical procedure so that concentration of the electrical energy to the patient tissue improves both speed with which the electrode is able to cut or cauterize the tissue while also reducing likelihood of tissue damage in tissue surrounding the cut or cauterized tissue, the improved speed with which the electrode is able to cut or cauterize tissue providing more rapid feedback that can be used to regulate power levels applied to the electrode; and

an electrosurgical wave generator electrically coupled to the electrode, the wave generator comprising;

a power source for providing electrical energy to said electrode working surface at a specified frequency;

at least one of a voltage sensor and a current sensor coupled between the power source and the electrode for sensing one or more electrical feedback parameters from which the tissue impedance can be essentially continuously sampled so that the tissue impedance can be used to rapidly adjust power levels applied to the electrode during a cut or cauterize procedure to avoid application of excess power and tissue damage; and

a processor programmed with executable instructions for processing the sensed electrical parameters to re-compute tissue impedance for each sample taken while cutting or cauterizing the tissue so that (i) as cutting or cauterizing the tissue is initiated, power to the electrode is rapidly increased up to a pre-determined tissue impedance level, and then (ii) as tissue impedance increases above the pre-determined tissue impedance level, the power to the electrode is rapidly reduced in inverse proportion to further increases in tissue impedance.

2. An electrosurgical system as recited in claim 1, wherein the sharpened working surface of the electrode has a thickness of between about 0.0254 mm and about 0.127 mm.

3. An electrosurgical system as recited in claim 1, wherein the electrode has a reduced mass to minimize the amount of latent heat retained by the electrode and transferred to the surrounding tissue.

4. An electrosurgical system as recited in claim 1, wherein the wave generator includes both a voltage and a current sensor that sense both a voltage and a current from the power applied to the electrode working surface.

5. An electrosurgical system as recited in claim 4, wherein the processor of the wave generator is programmed to calculate an impedance of the electrosurgical system from the sensed voltage and current.

6. An electrosurgical system as recited in claim 1, wherein the electrical energy level of the power applied to the electrode working surface as a result of the sampled parameters and the re-computed tissue impedance for each sample corresponds to a customized power curve that is inversely proportional to the impedance of the tissue once the impedance reaches the pre-determined tissue impedance level as determined during the cut or cauterize procedure based on the samples.

7. An electrosurgical system as recited in claim 6, wherein the wave generator comprises a processor that is programmed to:

use the computed impedance of each sample to calculate the electrical energy level on the customized power curve associated with the computed impedance level; and

adjust the level of electrical energy being transmitted through the electrode working surface to the level on the customized power curve associated with the computed impedance.

8. An electrosurgical system as recited in claim 7, wherein, prior to determining that the tissue impedance has reached the pre-determined tissue impedance level, the customized power curve maintains the electrical energy being transmitted to the patient tissue at a maximum power level, which corresponds to tissue impedance levels on the customized power curve of between about 100 ohms and about 200 ohms.

9. An electrosurgical system as recited in claim 8, wherein the maximum power level of electrical energy transmitted to the patient tissue is about 150 watts.

10. An electrosurgical system as recited in claim 1, wherein the electrical parameters are sampled and the tissue impedance is re-computed so that the wave generator is capable of adjusting the level of a lied power at the electrode working surface about every 20 milliseconds.

11. An electrosurgical system comprising:

an electrosurgical electrode adapted to transmit electrical energy to patient tissue during an electrosurgical procedure, the electrode having a configuration that enhances rapid feedback used to automatically correct and regulate power levels applied to the electrode, the electrode comprising a working edge that is sharpened to concentrate the electrical energy transmitted from the electrode to the patient tissue during an electrosurgical procedure so that concentration of the electrical energy to the patient tissue improves both speed with which the electrode is able to cut or cauterize the tissue while also reducing likelihood of tissue damage in tissue surrounding the cut or cauterized tissue, the improved speed with which the electrode is able to cut or cauterize tissue providing more rapid feedback that can be used to regulate power levels applied to the electrode, and the electrode having a limited mass which limits the amount of latent heat the electrode is able to retain; and

an electrosurgical wave generator electrically coupled to the electrode, the wave generator comprising;

a power source for providing electrical energy to said electrode working edge at a specified frequency;

a voltage sensor and a current sensor coupled between the power source and the electrode for sensing both voltage and current at the electrode at a sampling rate of about every 20 milliseconds in order to provide voltage and current feedback parameters from which the tissue impedance can be essentially continuously re-computed about every 20 milliseconds and then used to rapidly adjust power levels applied to the electrode during a cut or cauterize procedure to avoid application of excess power and tissue damage; and

a processor programmed with executable instructions for processing the sensed voltage and current to re-compute tissue impedance for each sample taken while cutting or cauterizing the tissue so that (i) as cutting or cauterizing the tissue is initiated, power to the electrode is initially rapidly increased up to a pre-determined tissue impedance level, and then (ii) as tissue impedance increases above the pre-determined tissue impedance level, the power to the electrode is rapidly reduced in inverse proportion to further increases in tissue impedance.

12. An electrosurgical system as recited in claim 11, wherein the sharpened working edge of the electrode has a thickness in the range of about 0.1270 mm to about 0.0254 mm.

13. An electrosurgical system as recited in claim 11, wherein the sharpened working edge of the electrode is coated with a non-stick coating.

14. An electrosurgical system as recited in claim 11, wherein the parameters of the electrode'"'"'s working edge are used by the processor to automatically adjust the electrical energy being applied by the working edge to the patient tissue in real-time based on a sampling rate of about 20 milliseconds.

15. An electrosurgical system as recited in claim 11, wherein the wave generator is adapted to generate electrical energy in a range from about 0 watts to about 150 watts.

16. An electrosurgical system comprising:

an electrosurgical electrode adapted to transmit electrical energy to patient tissue during an electrosurgical procedure, the electrode having a configuration that enhances rapid feedback used to automatically correct and regulate power levels applied to the electrode, the electrode comprising a plurality of working surfaces with differing lengths that are angled relative to one another, but wherein each working surface has a thickness in the range of about 0.254 mm to about 0.1270 mm that is sharpened to concentrate the electrical energy transmitted from the electrode to the patient tissue during an electrosurgical procedure so that concentration of the electrical energy to the patient tissue improves both speed with which the electrode is able to cut or cauterize the tissue while also reducing likelihood of tissue damage in tissue surrounding the cut or cauterized tissue, the improved speed with which the electrode is able to cut or cauterize tissue providing more rapid feedback that can be used to regulate power levels applied to the electrode, and the electrode having an overall thickness of about 0.4318 mm so that the electrode has a limited mass which limits the amount of latent heat the electrode is able to retain; and

an electrosurgical wave generator electrically coupled to the electrode, the wave generator comprising;

a power source for providing electrical energy to said electrode working surface at a specified frequency;

a voltage sensor and a current sensor coupled between the power source and the electrode for sensing both voltage and current at the electrode at a sampling rate of about every 20 milliseconds in order to provide voltage and current feedback parameters from which the tissue impedance can be essentially continuously re-computed about every 20 milliseconds and then used to rapidly adjust power levels applied to the electrode during a cut or cauterize procedure to avoid application of excess power and tissue damage; and

a processor programmed with executable instructions for processing the sensed voltage and current to re-compute tissue impedance for each sample taken while cutting or cauterizing the tissue so that (i) as cutting or cauterizing the tissue is initiated, power to the electrode is initially rapidly increased up to a pre-determined tissue impedance level, and then (ii) as tissue impedance increases above the pre-determined tissue impedance level, the power to the electrode is rapidly reduced in inverse proportion to further increases in tissue impedance.

17. An electrosurgical system as recited in claim 16, wherein the re-computed impedance is directly proportional to the velocity at which the electrode working edge is moved through the tissue so that the level of electrical power applied to the electrode is related to the speed at which the tissue is cut by the working edge.

18. An electrosurgical system as recited in claim 16, wherein the wave generator is adapted to generate electrical energy for transmission to patient tissue through the electrode in a range from about 0 watts to about 150 watts.

19. A computer-implemented method of controlling power to a working surface of an electrode of an electrosurgical system used to cut or cauterize a patient'"'"'s tissue during a medical procedure, comprising:

providing electrical energy to said electrode working surface at a specified frequency;

sampling at a rate of about 20 milliseconds the voltage and current at said electrode working surface so that tissue impedance can be derived from the voltage and current samples and then used to rapidly adjust power levels applied to the electrode during a cut or cauterize procedure to avoid application of excess power and tissue damage; and

using a processor programmed with executable instructions to process the sensed voltage and current parameters in order to re-compute tissue impedance for each sample taken while cutting or cauterizing the tissue so that (i) as cutting or cauterizing the tissue is initiated, power to the electrode is rapidly increased up to a pre-determined tissue impedance level, and then (ii) as tissue impedance increases above the pre-determined tissue impedance level, the power to the electrode is rapidly reduced in inverse proportion to further increases in tissue impedance.

20. An electrosurgical wave generator having a processor for implementing a computer-implemented method of controlling power to a working surface of an electrode of an electrosurgical system used to cut or cauterize a patient'"'"'s tissue during a medical procedure, and wherein the processor includes computer-executable instructions for implementing a method comprised of:

providing electrical energy to said electrode working surface at a specified frequency;

sampling at a rate of about 20 milliseconds the voltage and current at said electrode working surface so that tissue impedance can be derived from the voltage and current samples and then used to rapidly adjust power levels applied to the electrode during a cut or cauterize procedure to avoid application of excess power and tissue damage; and

using a processor programmed with executable instructions to process the sensed voltage and current parameters in order to re-compute tissue impedance for each sample taken while cutting or cauterizing the tissue so that (i) as cutting or cauterizing the tissue is initiated, power to the electrode is rapidly increased up to a pre-determined tissue impedance level, and then (ii) as tissue impedance increases above the pre-determined tissue impedance level, the power to the electrode is rapidly reduced in inverse proportion to further increases in tissue impedance.