Impedance feedback monitor with query electrode for electrosurgical instrument

An electrosurgical device having an end effector, wherein said end effector comprises:

• first and second opposing interfacing surfaces, said interfacing surfaces capable of engaging tissue therebetween, and end effector capable of receiving electrosurgical energy therein,
• electrically isolated first and second therapeutic poles comprised of first and second electrically opposite therapeutic electrodes capable of conducting electrosurgical energy therethrough;
• electrically isolated first and second sensing poles comprised of first and second electrically opposite query electrodes capable of conducting electrosurgical energy therebetween;
• wherein said first therapeutic electrode is located on at least one of said first and second interfacing surfaces and said second therapeutic electrode is located on said end effector so that electrosurgical energy may be communicated between said therapeutic poles through the tissue engaged by said interfacing surfaces to electrosurgically treat the tissue;
• and
• wherein said first query electrode is located on at least one of said first and second interfacing surfaces and said second query electrode is located on said end effector so that sensing electrosurgical energy may be communicated between said sensing poles to measure an electrical parameter of said tissue between said sensing poles.

An electrosurgical device having an end effector, wherein said end effector comprises:

• first and second opposing interfacing surfaces, said interfacing surfaces capable of engaging tissue therebetween, and end effector capable of receiving electrosurgical energy therein,
• electrically isolated first and second therapeutic poles comprised of first and second electrically opposite therapeutic electrodes capable of conducting electrosurgical energy therethrough;
• electrically isolated first and second sensing poles comprised of first and second electrically opposite query electrodes capable of conducting electrosurgical energy therebetween;
• wherein said first therapeutic electrode is located on at least one of said first and second interfacing surfaces and said second therapeutic electrode is located on said end effector so that electrosurgical energy may be communicated between said therapeutic poles through the tissue engaged by said interfacing surfaces to electrosurgically treat the tissue;
• and
• wherein said first query electrode is located on at least one of said first and second interfacing surfaces and said second query electrode is located on said end effector so that sensing electrosurgical energy may be communicated between said sensing poles to measure an electrical parameter of said sensing electrosurgical energy delivered between said sensing poles.

An electrosurgical method comprising:

• providing an electrosurgical device having an end effector, wherein said end effector comprises:
• first and second opposing interfacing surfaces, said interfacing surfaces capable of engaging tissue therebetween, and end effector capable of receiving electrosurgical energy therein, electrically isolated first and second therapeutic poles comprised of electrically opposite therapeutic electrodes capable of conducting electrosurgical energy therethrough;
• and
• electrically isolated first and second sensing poles comprised of electrically opposite query electrodes capable of conducting electrosurgical energy therebetween;
• wherein each of said therapeutic electrodes and each of said first and second query electrodes is located on a said interfacing surface;
• engaging tissue between said surfaces;
• delivering therapeutic electrosurgical energy to said tissue between said therapeutic electrodes;
• delivering sensing electrosurgical energy to said tissue between said sensing electrodes;
• measuring an electrical parameter of said sensing electrosurgical energy;
• determining when a desired tissue effect has occurred;
• and
• providing a signal indicating said tissue effect.

An electrosurgical device for treating tissue during a surgical procedure, said device comprising;

• a surgical instrument having a tissue treating portion including an end effector adapted to engage tissue to be treated;
• electrically isolated first and second therapeutic poles comprised of tissue contacting first and second therapeutic electrodes adapted to receive electrosurgical energy from an energy source and capable of conducting electrical energy therebetween, fat least said first therapeutic electrode being positioned on said tissue treating portion of said instrument and said second therapeutic electrode being positioned on said end effector;
• electrically isolated first and second query poles comprised of tissue contacting first and second query electrodes adapted to receive electrosurgical energy from an energy source and capable of conducting electrical energy therebetween, of said first query electrodes being positioned on said tissue treating portion of said instrument and said second query electrode being positioned on said end effector;
• a tissue treatment status determining device including electrical parameter measuring circuitry coupled to said query electrodes for measuring an electrical parameter of tissue engaged by said end effector, said tissue treatment status determining device adapted to provide an energy control signal for controlling electrosurgical energy supplied to said therapeutic electrodes.

A method of electrosurgically treating tissue, said method comprising the steps of:

• providing an electrosurgical instrument including electrically different query electrodes;
• electrically different therapeutic electrodes;
• and an end effector comprising one or more of said tissue treating electrodes and one or more of said query electrodes;
• applying sensing electrosurgical energy through said one or more query electrodes to tissue to be electrosurgically treated;
• measuring an electrical parameter of the tissue between said query electrodes;
• generating a signal representative of the measured electrical parameter of tissue between said query electrodes;
• determining a therapeutic target electrical parameter value from said measured electrical parameter;
• comparing subsequent measured electrical parameters to said target value;
• generating a control signal to control the electrosurgical energy to said electrosurgical instrument in response to said measured electrical parameter reaching said target value;
• and
• controlling the energy applied to the tissue through said one or more therapeutic electrodes in response to said control signal.

A method of electrosurgically treating tissue, said method comprising the steps of:

• providing an electrosurgical instrument including electrically different query electrodes;
• electrically different therapeutic electrodes;
• and an end effector comprising one or more of said tissue treating electrodes and one or more of said query electrodes;
• applying sensing electrosurgical energy through said one or more query electrodes to tissue to be electrosurgically treated;
• measuring the impedance of the tissue between said query electrodes;
• generating an impedance signal representative of the measured impedance value of tissue between said query electrodes;
• determining a representative minimum impedance value from said impedance signal;
• determining a representative target impedance value as a function of said minimum impedance value;
• comparing subsequent impedance signals to said target impedance value;
• generating a control signal to control the electrosurgical energy to said electrosurgical instrument in response to said measured impedance value reaching said target impedance value;
• and
• controlling the energy applied to the tissue through said one or more therapeutic electrodes in response to said control signal.

A method of electrosurgically treating tissue comprising the steps of:

• providing an electrosurgical instrument having an end effector comprising first and second tissue engaging surfaces, one of said first and second tissue engaging surfaces including thereon a first tissue contacting therapeutic electrode electrically connected to a first pole of an electrosurgical therapeutic system, and one of said first and second tissue engaging surfaces containing thereon a second tissue contacting therapeutic electrode electrically connected to a second pole of the therapeutic system;
• one of said first and second tissue engaging surfaces including thereon a first query electrode electrically connected to a first pole of an impedance sensing system and one of said first and second tissue engaging surfaces including thereon a second query electrode electrically connected to a second pole of said impedance sensing system;
• engaging tissue to be treated between the first and second tissue engaging surfaces;
• selectively controlling electrosurgical energy supplied to the first and second tissue contacting therapeutic electrodes for treating tissue positioned therebetween;
• measuring the impedance of the treated tissue between the first and second query electrodes with said first and second query electrodes;
• setting a threshold impedance value at which tissue treatment is complete;
• comparing measured impedance values to the threshold impedance value;
• and
• controlling or switching off the electrosurgical energy coupled to the first and second therapeutic electrodes upon the condition of the measured impedance value reaching or exceeding the threshold impedance value.

An electrosurgical impedance feedback control device, said device comprising:

• an energy control signal generating device for generating a control signal to control electrosurgical energy supplied from an energy source to one or more therapeutic electrodes positioned on a tissue treating portion of a surgical instrument;
• impedance measurement circuitry adapted to be coupled to at least one tissue contacting query electrode positioned on the tissue treating portion of the surgical instrument and to an energy source arranged to supply therapeutic electrosurgical energy to the one or more therapeutic electrodes positioned on the tissue treating portion of the surgical instrument,
• wherein said impedance measurement circuitry is adapted to measure the impedance of tissue engaged by the tissue treating portion of the surgical instrument;
• wherein said impedance measuring circuitry comprises:
• a first device for determining a minimum impedance value;
• a target determining device coupled to said first device, for determining the target impedance value as a function of said minimum impedance value;
• and
• a first comparison device for comparing measured impedance values to said target impedance value and generating a signal indicating whether said measured impedance value exceeds said target impedance value.