System and method for tissue sealing
First Claim
1. An electrosurgical generator, comprising:
- an RF output stage configured to supply electrosurgical energy to tissue via at least one active electrode configured to apply electrosurgical energy to tissue;
sensing circuitry configured to measure impedance of tissue and measure a phase between voltage and current waveforms of the electrosurgical energy delivered to tissue; and
a controller programmed to;
determine whether a tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid;
generate a target impedance trajectory as a function of measured impedance and a predetermined desired rate of change of impedance based on the tissue reaction determination, wherein the target impedance trajectory includes a plurality of target impedance values for each of a plurality of time-steps;
drive tissue impedance along the target impedance trajectory by adjusting the output level of the electrosurgical generator to substantially match tissue impedance to a corresponding target impedance value for at least a predetermined minimum time period;
determine an open circuit based on the phase being above an upper phase threshold; and
determine a short circuit based on the phase being below a lower phase threshold.
3 Assignments
0 Petitions
Accused Products
Abstract
An electrosurgical generator is disclosed. The generator includes an RF output stage configured to supply electrosurgical energy to tissue via at least one active electrode configured to apply electrosurgical energy to tissue; sensing circuitry configured to measure impedance of tissue; and a controller. The controller is configured to determine occurrence of a tissue reaction as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid; generate a target impedance trajectory as a function of measured impedance and desired rate of change based on the tissue reaction determination, wherein the target impedance trajectory includes a plurality of target impedance values; and drive tissue impedance along the target impedance trajectory by adjusting the output of the electrosurgical generator to substantially match tissue impedance to a corresponding target impedance for at least a predetermined minimum time period.
795 Citations
12 Claims
-
1. An electrosurgical generator, comprising:
-
an RF output stage configured to supply electrosurgical energy to tissue via at least one active electrode configured to apply electrosurgical energy to tissue; sensing circuitry configured to measure impedance of tissue and measure a phase between voltage and current waveforms of the electrosurgical energy delivered to tissue; and a controller programmed to; determine whether a tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid; generate a target impedance trajectory as a function of measured impedance and a predetermined desired rate of change of impedance based on the tissue reaction determination, wherein the target impedance trajectory includes a plurality of target impedance values for each of a plurality of time-steps; drive tissue impedance along the target impedance trajectory by adjusting the output level of the electrosurgical generator to substantially match tissue impedance to a corresponding target impedance value for at least a predetermined minimum time period; determine an open circuit based on the phase being above an upper phase threshold; and determine a short circuit based on the phase being below a lower phase threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An electrosurgical system, comprising:
-
an RF output stage configured to supply electrosurgical energy to tissue; sensing circuitry configured to measure impedance of tissue and a phase between voltage and current waveforms of the electrosurgical energy delivered to the tissue; a controller programmed to; determine whether a tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid; generate a target impedance trajectory as a function of measured impedance and a predetermined desired rate of change of impedance based on the tissue reaction determination, wherein the target impedance trajectory includes a plurality of target impedance values for each of a plurality of time-steps; drive tissue impedance along the target impedance trajectory by adjusting the output level of the electrosurgical generator to substantially match tissue impedance to a corresponding target impedance value for at least a predetermined minimum time period; determine an open circuit based on the phase being above an upper phase threshold; and determine a short circuit based on the phase being below a lower phase threshold; and an electrosurgical instrument including at least one active electrode configured to apply electrosurgical energy to tissue. - View Dependent Claims (9, 10, 11, 12)
-
Specification