Surgical instrument
First Claim
1. A bipolar radio frequency electrosurgical instrument comprising at least first:
- and second electrodes, each of the first and second electrodes having a tissue-treatment region wherein, in use, current flows in a pathway from the tissue-treatment region of one electrode to the tissue-treatment region of the other electrode, and at least one dielectric element made of a dielectric material, the dielectric element having a tissue-contacting portion and being positioned in the current pathway between the tissue-treatment regions of the first and second electrodes, the dielectric element having a reactive impedance of less than 3,000 ohms/sq.mm. at 450 kHz.
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Accused Products
Abstract
An electrosurgical instrument for use in cutting and/or coagulating tissue includes a dielectric material, the dielectric material being positioned in the current pathway between the tissue-treatment regions of first and second electrodes. This can be achieved by providing one or more electrode surfaces coated with a dielectric material having a reactive impedance of less than 3,000 ohms/sq. mm. at 450 kHz. The dielectric coating acts to couple the RF signal into the tissue primarily by capacitive coupling, providing a more even heating of the tissue and the elimination of “hot spot”. Examples of electrosurgical instruments employing such coated electrodes include forceps, scissors or scalpel blade instruments.
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Citations
23 Claims
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1. A bipolar radio frequency electrosurgical instrument comprising at least first:
- and second electrodes, each of the first and second electrodes having a tissue-treatment region wherein, in use, current flows in a pathway from the tissue-treatment region of one electrode to the tissue-treatment region of the other electrode, and at least one dielectric element made of a dielectric material, the dielectric element having a tissue-contacting portion and being positioned in the current pathway between the tissue-treatment regions of the first and second electrodes, the dielectric element having a reactive impedance of less than 3,000 ohms/sq.mm. at 450 kHz.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- 12. An electrosurgical instrument comprising a bipolar cutting blade and a handpiece to which the blade is secured, the cutting blade comprising first and second electrodes and an electrical insulator spacing apart the electrodes, each of the first and second electrodes having a tissue-treatment region, wherein, in use, current flows in a pathway from the tissue-treatment region of one electrode to the tissue treatment region of the other electrode, and at least one dielectric element made of a dielectric material, the dielectric element having a tissue-contacting portion and being positioned in the current pathway between the tissue-treatment regions of the first and second electrodes, the dielectric element having a reactive impedance of less than 3,000 ohms/sq. mm. at 450 kHz.
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14. An electrosurgical system for treating tissue, the system comprising a bipolar radio frequency instrument comprising at least first and second electrodes, each of the first and second electrodes having a tissue-treatment region, and an electrosurgical generator adapted to supply a radio frequency output to the electrodes of the instrument at a frequency f, such that current flows in a pathway from the tissue-treatment region of one of the electrodes to the other, and a dielectric material, the dielectric material having a tissue-contacting portion and being positioned in the current pathway between the tissue-treatment regions of the first and second electrodes, the dielectric element having a reactive impedance at the frequency f of less than 3,000 ohms/sq. mm.
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15. An electrosurgical system for treating tissue, the system comprising a bipolar radio frequency instrument comprising at least first and second electrodes, each of the first and second electrodes having a tissue-treatment region, and an electrosurgical generator adapted to supply a radio frequency output to the electrodes of the instrument at a frequency of 6.79 MHz, such that current flows in a pathway from the tissue-treatment region of one of the electrodes to the tissue treatment region of the other electrode, and at least one dielectric element made of a dielectric material, the dielectric element having a tissue-contacting portion and being positioned in the current pathway between the tissue-treatment regions of the first and second electrodes, the dielectric element having a reactive impedance at the 6.79 MHz of less than 3,000 ohms/sq. mm.
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16. An electrosurgical system for treating tissue, the system comprising a bipolar radio frequency instrument comprising at least first and second electrodes, each of the first and second electrodes having a tissue-treatment region, and an electrosurgical generator adapted to supply a radio frequency output to the electrodes of the instrument at a frequency of 13.56 MHz, such that current flows in a pathway from the tissue-treatment region of one of the electrodes to tissue treatment region of the other electrode, and at least one dielectric element made of a dielectric material, the dielectric element having a tissue-contacting portion and being positioned in the current pathway between the tissue-treatment regions of the first and second electrodes, the dielectric element having a reactive impedance at the 13.56 MHz frequency of less than 3,000 ohms/sq. mm.
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17. An electrosurgical system for treating tissue, the system comprising a bipolar radio frequency instrument comprising at least first and second electrodes, each of the first and second electrodes having a tissue-treatment region, and an electrosurgical generator adapted to supply a radio frequency output to the electrodes of the instrument at a frequency of 27.12 MHz, such that current flows in a pathway from the tissue-treatment region of one of the electrodes to the tissue treatment region of the other electrode, and at least one dielectric element made of a dielectric material, the dielectric element having a tissue-contacting portion and being positioned in the current pathway between the tissue-treatment regions of the first and second electrodes, the dielectric element having a reactive impedance at the 27.12 MHz frequency of less than 3,000 ohms/sq.mm.
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18. An electrosurgical system for treating tissue, the system comprising a bipolar radio frequency instrument comprising at least first and second electrodes, each of the first and second electrodes having a tissue-treatment region, and an electrosurgical generator adapted to supply a radio frequency output to the electrodes of the instrument at a frequency of 40.68 MHz, such that the current flows in a pathway from the tissue-treatment region of one of the electrodes to the tissue treatment region of the other electrode, and at least one dielectric element made of a dielectric material, the dielectric element having a tissue-contacting portion and being positioned in the current pathway between the tissue treatment regions of the first and second electrodes, the dielectric element having a reactive impedance at the 40.68 MHz frequency of less than 3,000 ohms/sq.mm.
- 19. An electrosurgical instrument comprising a bipolar tissue cutting blade and a handpiece to which the blade is secured, wherein the blade comprises a laminar combination of first and second electrically conductive electrodes spaced apart by an intermediate insulating layer, the electrodes having neighbouring co-extensive edge portions forming tissue-treatment regions, and wherein the blade further comprises at least one dielectric element formed as a tissue-contacting extension of the edge portion of the second electrode, the dielectric element being made of a dielectric material having a relative dielectric constant which is at least 10 times greater than that of the material of the intermediate layer.
Specification