Power-controlled waveform in electrosurgical systems
Apparatus and associated methods relate to controlling electrical power of an electrotherapeutic signal that is provided to a biological tissue engaged by an electrosurgical instrument during a medical procedure. Electrical power—a product of a voltage difference across and an electrical current conducted by the engaged biological tissue—is controlled according to a therapeutic schedule. The electrotherapeutic schedule can be reduced or terminated in response to a termination criterion being met. In some examples, the termination criterion is a current characteristic, such as, for example, a decrease in current conducted by the engaged biological tissue. In some examples, the termination criterion is a biological tissue resistance characteristic, such as, for example, an increase in the biological tissue resistance that exceeds a predetermined delta resistance value.
1. A surgical generator configured to generate and provide controlled electrical power of a therapeutic signal to biological tissue in electrical communication with an instrument, the surgical generator comprising:
a control circuit in communication with an electrical-energy source, the electrical-energy source electrically coupled to the instrument and configured to generate the therapeutic signal, the control circuit configured to:
control the electrical power of the therapeutic signal provided to the biological tissue during a portion of a non-sealing therapeutic phase according to a therapeutic plan by monotonically increasing the electrical power as a function of resistance, wherein the electrical power decreases to a non-zero level between the non-sealing therapeutic phase and a subsequent therapeutic phase.
2. The surgical generator of claim 1 , wherein the control circuit is configured to:
control a voltage of the therapeutic signal provided to the biological tissue during a portion of a drying phase according to the therapeutic plan.
3. The surgical generator of claim 2 , wherein the control circuit is configured to:
monitor the voltage of the therapeutic signal; and
maintain the voltage when the voltage meets a voltage threshold.
4. The surgical generator of claim 1 , wherein the control circuit is configured to:
control the electrical power of the therapeutic signal provided to the biological tissue during the portion of the therapeutic phase using a pre-defined power curve.
5. The surgical generator of claim 4 , wherein the pre-defined power curve includes a linear portion.
6. The surgical generator of claim 4 , wherein the pre-defined power curve includes two or more linear portions.
7. A method of delivering controlled electrical power of a therapeutic signal to biological tissue in electrical communication with an instrument, the method comprising:
generating, using an electrical-energy source electrically coupled to the instrument, the therapeutic signal; and
controlling the electrical power of the therapeutic signal provided to the biological tissue during a portion of a non-sealing therapeutic phase according to a therapeutic plan by monotonically increasing modifying the electrical power as a function of resistance, wherein the electrical power decreases to a non-zero level between the non-sealing therapeutic phase and a subsequent therapeutic phase.
8. The method of claim 7 , comprising:
controlling a voltage of the therapeutic signal provided to the biological tissue during a portion of a drying phase according to the therapeutic plan.
9. The method of claim 8 , comprising:
monitoring the voltage of the therapeutic signal; and
maintaining the voltage when the voltage meets a voltage threshold.
10. The method of claim 7 , comprising:
controlling the electrical power of the therapeutic signal provided to the biological tissue during the portion of the therapeutic phase using a pre-defined power curve.
11. The method of claim 10 , wherein the pre-defined power curve includes a linear portion.
12. The method of claim 11 , wherein the pre-defined power curve includes two or more linear portions.
13. A surgical generator configured to generate and provide controlled electrical power of a therapeutic signal to biological tissue in electrical communication with an instrument, the surgical generator comprising:
a control circuit in communication with an electrical-energy source, the electrical-energy source electrically coupled to the instrument and configured to generate the therapeutic signal, the control circuit configured to:
control the electrical power of the therapeutic signal provided to the biological tissue during a portion of a non-sealing therapeutic phase according to a therapeutic plan by monotonically increasing the electrical power as a function of current, wherein the electrical power decreases to a non-zero level between the non-sealing therapeutic phase and a subsequent therapeutic phase.
14. The surgical generator of claim 13 , wherein the function of current is a function of an instantaneous measured change in current.
15. A method of delivering controlled electrical power of a therapeutic signal to biological tissue in electrical communication with an instrument, the method comprising:
generating, using an electrical-energy source electrically coupled to the instrument, the therapeutic signal; and
controlling the electrical power of the therapeutic signal provided to the biological tissue during a portion of a non-sealing therapeutic phase according to a therapeutic plan by monotonically increasing the electrical power as a function of current, wherein the electrical power decreases to a non-zero level between the non-sealing therapeutic phase and a subsequent therapeutic phase.
16. The method of claim 15 , wherein the function of current is a function of an instantaneous measured change in current.
17. The method of claim 16 , wherein the function of the instantaneous measured change in current is a linear function.