POWER CONTROL FOR AN ELECTROSURGICAL VESSEL SEALER
A power delivery approach for delivering power to an electrosurgical vessel sealer when the jaws of the sealer surround tissue to be desiccated. Power delivery commences at a starting point that is at least 40 Joules and then decreases over a first predetermined period of time to a predetermined minimum power level to provide approximately 15 Joules in total. When the predetermined minimum power level is reached, power is then continuously increased over a second predetermined period of time to fully desiccate the tissue. Power delivery is terminated prior to over-desiccation of the tissue.
1 . An electrosurgical system, comprising:
a vessel sealer having a pair of jaws; and
an electrosurgical generator coupled to the pair of jaws of the vessel sealer and configured to output radiofrequency energy to the vessel sealer according to a predetermined continuous power curve;
wherein the predetermined continuous power curve comprises a first power delivery segment that commences at a first power level and continuously decreases to a second, non-zero power level and a second power delivery segment that commences with the second, non-zero power level and increases to a final power level.
2 . The electrosurgical system of claim 1 , wherein the first power delivery segment occurs during a time period of between 0.250 and 9.75 seconds.
3 . The electrosurgical system of claim 1 , wherein the second power delivery segment occurs during a time period of between 0.250 and 9.75 seconds.
4 . The electrosurgical system of claim 1 , wherein the first power delivery segment delivers an amount of power that will not cause any tissue trapped in the pair of jaws to reach a temperature that results in boiling of any moisture in the tissue.
5 . The electrosurgical system of claim 1 , wherein the first power delivery segment delivers an amount of power that causes any tissue trapped in the pair of jaws to desiccate.
6 . The electrosurgical system of claim 1 , wherein the final power level will not cause over-desiccation of any tissue trapped in the pair of jaws.
7 . The electrosurgical system of claim 1 , wherein the second power delivery segment ends when any tissue in the pair of jaws has an impedance that exceeds a predetermined value.
8 . The electrosurgical system of claim 1 , wherein the first power delivery segment has a shape selected from the group consisting of linear, concave, convex, and combinations thereof.
9 . The electrosurgical system of claim 1 , wherein the second power delivery segment has a shape selected from the group consisting of linear, concave, convex, and combinations thereof.
10 . The electrosurgical system of claim 1 , wherein the first power delivery segment comprises an exponential decay curve and the second power delivery segment is linear.
11 . A method of controlling the power output from an electrosurgical generator to a vessel sealer having a pair of jaws, comprising:
providing the vessel sealer having the pair of jaws;
coupling the electrosurgical generator to the pair of jaws of the vessel sealer;
powering the electrosurgical generator to output radiofrequency energy to the vessel sealer according to a predetermined continuous power curve, wherein the predetermined continuous power curve comprises a first power delivery segment that commences at a first power level and continuously decreases to a second power level and a second power delivery segment that commences with the second power level and increases to a final power level.
12 . The electrosurgical system of claim 11 , wherein the first power delivery segment occurs during a time period of between 0.250 and 9.75 seconds.
13 . The electrosurgical system of claim 11 , wherein the second power delivery segment occurs during a time period of between 0.250 and 9.75 seconds.
14 . The electrosurgical system of claim 1 , wherein the first power delivery segment delivers an amount of power that will not cause any tissue trapped in the pair of jaws to reach a temperature that results in boiling of any moisture in the tissue.
15 . The electrosurgical system of claim 11 , wherein the second power delivery segment ends when any tissue in the pair of jaws has an impedance that exceeds a predetermined value.