Patent Application
20230225785
The present disclosure relates to an electrosurgical electrode and, more particularly, to an electrosurgical electrode including a composite coating.
Electrosurgery involves application of high radio frequency (RF) electrical current to a surgical site to cut, ablate, desiccate, or coagulate tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency alternating current from the electrosurgical generator to the targeted tissue. A patient return electrode is placed remotely from the active electrode to conduct the current back to the generator.
Monopolar electrodes apply RF electrical energy to heat the tissue to transect or achieve hemostasis. Thus, there is a need for a coating which can reduce the unexpected thermal damage and secondary damage caused by tissue adhesion during application of RF energy.
Polytetrafluoroethylene (PTFE) coating disposed directly on electrode surface may decompose and peel from the electrode due to high temperature and arcing during application of RF energy. This may cause a decrease in blade performance due to tissue sticking to the surface of the electrode.
The present disclosure provides an electrosurgical electrode, such as a monopolar blade electrode used in open surgery and laparoscopic surgery, having a composite coating, which is used to prevent secondary damage caused by intraoperative thermal damage and tissue adhesion. The electrode includes a composite coating having a PTFE primer coating and a second coating formed of perfluoroalkoxy alkanes (PFA), which is a copolymer of hexafluoropropylene and perfluoroethers. Compared with traditional PTFE coated monopolar blade, composite coating has better surface adhesion and anti-sticking performance.
According to one embodiment of the present disclosure, an electrosurgical electrode is disclosed. The electrode includes a conductive rod having a working portion at a distal end portion. The electrode also includes a composite coating disposed on the working portion. The composite coating includes a first coating disposed on an outer surface of the working portion and a second coating disposed over the first coating.
According to another embodiment of the present disclosure, an electrosurgical electrode is disclosed. The electrode includes a conductive rod including a distal end portion having a working portion and a proximal end portion configured to couple to an electrosurgical instrument. The electrode also includes a composite coating disposed on the working portion. The composite coating includes a first coating formed from a first polymer disposed on an outer surface of the working portion and a second coating disposed over the first coating, the second coating formed from a second polymer, different from the first polymer.
According to one aspect of any of the above embodiments, the outer surface of the working portion has a roughness from about 0.6 Ra to about 0.8 Ra. The first coating may include polytetrafluoroethylene. The second coating may be a powder coating of perfluoroalkoxy alkanes.
According to another aspect of any of the above embodiments, the first coating has a thickness from about 7 μm to about 9 μm. The second coating has a thickness from 12 μm to about 15 μm. The composite coating has a thickness from about 19 μm to about 24 μm. The second coating has a roughness from about 0.2 Ra to about 0.4 Ra.
According to a further embodiment of the present disclosure, a method for making an electrosurgical electrode is disclosed. The method includes texturing a working portion of an electrosurgical electrode; applying a first coating formed from a first polymer to an outer surface of the working portion; and applying a second coating onto the first coating, the second coating formed from a second polymer, different from the first polymer.
According to one aspect of the above embodiment, texturing including sandblasting the working portion to have a roughness from about 0.6 Ra to about 0.8 Ra. Applying the first coating may also include achieving a thickness from about 7 μm to about 9 μm for the first coating. Applying the second coating may also include achieving a thickness from about 19 μm to about 24 μm for the second coating.
The present disclosure may be understood by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:
Embodiments of the presently disclosed electrosurgical system are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to the portion of the surgical instrument coupled thereto that is closer to the patient, while the term “proximal” refers to the portion that is farther from the patient.
In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Those skilled in the art will understand that the present disclosure may be adapted for use with either an endoscopic instrument, a laparoscopic instrument, or an open instrument. It should also be appreciated that different electrical and mechanical connections and other considerations may apply to each particular type of instrument.
Referring to
With reference to
The working portion 38 includes a composite coating 40 disposed on its outer surface. With reference to
After the working portion 38 is roughened, the first coating 42 is applied to achieve a desired thickness. The first coating 42 may have a thickness from about 7 μm to about 9 μm. The first coating 42 is formed from a polymer, such as PTFE, which may be applied by atomizing or aerosolizing a PTFE solution using a high-pressure air supply and spraying the PTFE solution on the surface of the working portion 38. Thereafter, the first coating 42 is dried and sintered.
Once the first coating 42 has solidified, the second coating 44 is applied to the first coating 42. The second coating 44 may be formed from a second polymer, that is different from the first polymer of the first coating 42. The second coating 44 may be a powder coating formed from PFA particles and may be formed by spraying onto the first coating 42 until a desired thickness is achieved. The second coating 44 may have a thickness from about 12 μm to about 15 μm. The composite coating 40 may have a combined thickness from about 19 μm to about 24 μm.
With reference to
The following Examples illustrate embodiments of the present disclosure. These Examples are intended to be illustrative only and are not intended to limit the scope of the present disclosure. Also, parts and percentages are by weight unless otherwise indicated. As used herein, “room temperature” or “ambient temperature” refers to a temperature from about 20° C. to about 25° C.
This Example describes effectiveness of the dual-layer PTFE/PFA coating according to the present disclosure as compared to uncoated, silicone, and single layer PTFE coated electrodes.
Four electrodes were used to determine effectiveness of the coating of the present disclosure including an uncoated electrode, a silicone coated electrode, a PTFE coated electrode, and a composite coated electrode according to the present disclosure. Each of the electrodes were used with a VALLEYLAB™ FT10® generator available from Medtronic of Minneapolis, Minn. in a manual cut mode at 10 Watts setting. The electrodes were used to make incisions in porcine liver tissue and are shown in
A fatigue test was also performed on the four electrodes to determine their effectiveness after multiple cuts. The uncoated electrode was substituted with another PTFE coated electrode (PTFE 2). For the fatigue test, twenty cuts were made with each electrode and the electrodes were tested until failure of the coatings to evaluate durability of coatings. The electrodes were mounted to a Gantry system to control cutting length, depth, and speed. In particular, the electrodes were used to make a 40 mm cut, having approximately a 2 mm depth, at a speed of about 10 mm/s. During cutting the generator was in manual cutting mode at 15 Watts setting.
The first 1-15 cuts, width of cuts made with the composite coated electrode were narrower than those made with electrodes having other coatings. Furthermore, the first PTFE coated electrode (PTFE1) failed after 10 cuts. After 20 cuts, the silicone coated electrode failed to cut completely and could not form unbroken cut marks whereas the composite coated electrode cut smoothly and flatly. In addition, stickiness and cleanability of each of the electrodes was evaluated and the results are included in the table of
While several embodiments of the disclosure have been shown in the drawings and/or described herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope of the claims appended hereto.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/102269 | 7/16/2020 | WO |
