Power estimation of distal end of electrosurgical instrument

1 . An apparatus, comprising:

a monitor configured to be electrically coupled between an electrosurgical instrument and an electrosurgical generator, wherein the electrosurgical instrument includes an active electrode and shield, and wherein the monitor comprises one or more of:

measurement circuitry configured to measure at least one of: an active voltage of the active electrode, an active current of the active electrode, and a shield current of the shield; and

identification circuitry configured to detect an identifier of the electrosurgical instrument, and to determine a parameter value corresponding with the identifier in a lookup table, and

capacitance measurement circuitry configured to measure a capacitance of the active electrode to the shield, wherein the capacitance measurement circuitry is configured to be switched into an active line of the monitor while the electrosurgical generator is not being actively keyed,

wherein the monitor includes a processor configured to determine an estimated real power output of the active electrode based on one or more of the active voltage, the active current, the shield current, the parameter value, and the capacitance of the active electrode to the shield, and

wherein the monitor is configured to display the estimated real power output of the active electrode of the electrosurgical instrument, or is configured to send the estimated real power output to the electrosurgical generator to be displayed or processed.

2 . The apparatus of claim 1 , wherein:

the monitor is configured to adjust a fault trip threshold for the shield current of the electrosurgical instrument based on one or more of the active voltage, the active current, the shield current, and the parameter value.

3 . The apparatus of claim 1 , wherein:

the processor is configured to determine the estimated real power output of the active electrode in real-time based on power output by the generator and a power drop determined from one or more of: the active voltage, the active current, the shield current, the parameter value, and the capacitance of the active electrode to the shield; and

the parameter value of the lookup table is a capacitance value of the electrosurgical instrument as periodically measured by the monitor.

4 . The apparatus of claim 1 , wherein:

the processor is configured to determine the estimated real power output of the active electrode by multiplying the active voltage and the active current together on a continuous or regularly-sampled basis and averaging a result of the multiplying.

5 . A system for performing an electrosurgical procedure, the system comprising:

an electrosurgical generator;

an electrosurgical instrument comprising an active electrode and a shield, wherein the active electrode receives power provided by the electrosurgical generator; and

a monitor configured to be electrically coupled between the electrosurgical instrument and the electrosurgical generator, to determine one or more electrical characteristics of the electrosurgical instrument, to estimate a real power output of the active electrode based on the determination of the one or more electrical characteristics, wherein the estimated real power output of the active electrode is determined based at least in part on a capacitance of the active electrode to the shield, and to display the estimated real power output of the active electrode of the electrosurgical instrument,

wherein the determination of the one or more electrical characteristics comprises one or more of:

measure an active voltage of the active electrode;

measure an active current of the active electrode;

measure a shield current of the shield;

determine a parameter value of the electrosurgical instrument based on a lookup table and a detected identifier of the electrosurgical instrument; and

measure the capacitance of the active electrode to the shield using a low-voltage capacitance measurement circuit that is switched in while the electrosurgical generator is turned off.

6 . The system of claim 5 , wherein:

the monitor is configured to adjust a fault trip threshold for the shield current of the electrosurgical instrument based on the one or more electrical characteristics.

7 . The system of claim 5 , wherein:

the monitor is configured to determine the estimated real power output of the active electrode in real-time based on power output by the electrosurgical generator and a power drop determined from one or more of: the active voltage, the active current, the shield current, the parameter value, and the capacitance of the active electrode to the shield.

8 . The system of claim 5 , wherein:

the monitor is configured to determine the estimated real power output of the active electrode by multiplying the active voltage and the active current together on a continuous basis and averaging a result of the multiplying.

9 . The system of claim 5 , wherein:

the parameter value of the lookup table is a capacitance value of the electrosurgical instrument as periodically measured by the monitor.

10 . The system of claim 5 wherein:

the parameter value of the lookup table is a capacitance value or power drop value of the electrosurgical instrument as measured in a factory and stored in memory of the monitor.

11 . A method of providing an accurate power estimate of a distal end of an electrosurgical instrument, the method comprising:

electrically coupling a monitor with the electrosurgical instrument, wherein the electrosurgical instrument includes an active electrode and a shield, and wherein the active electrode is configured to receive power from an electrosurgical generator;

determining, with the monitor, one or more electrical characteristics of the electrosurgical instrument, wherein the determining includes one or more of:

measuring an active voltage of the active electrode;

measuring an active current of the active electrode;

measuring a shield current of the shield;

determining a parameter value of the electrosurgical instrument based on a lookup table and a detected identifier of the electrosurgical instrument; and

measuring a capacitance of the active electrode to the shield using a low-voltage capacitance measurement circuit that is switched in while the electrosurgical generator is turned off;

estimating a real power output of the active electrode based on the determining of the one or more electrical characteristics, wherein the estimated real power output is determined based at least in part on the capacitance of the active electrode to the shield; and

displaying the estimated real power output of the active electrode of the electrosurgical instrument.

12 . The method of claim 11 , further comprising:

adjusting a fault trip threshold for the shield current of the electrosurgical instrument based on the one or more electrical characteristics.

13 . The method of claim 11 , further comprising:

determining the estimated real power output of the active electrode in real-time based on power output by the electrosurgical generator and a power drop determined from one or more of: the active voltage, the active current, the shield current, the parameter value, and the capacitance of the active electrode to the shield.

14 . The method of claim 11 , further comprising:

determining the estimated real power output of the active electrode by multiplying the active voltage and the active current together on a continuous basis and averaging a result of the multiplying.

15 . The method of claim 11 , wherein:

the parameter value of the lookup table is a capacitance value of the electrosurgical instrument as periodically measured by the monitor.

16 . The method of claim 11 , wherein:

the parameter value of the lookup table is a capacitance value or power drop value of the electrosurgical instrument as measured in a factory and stored in memory of the monitor.