Abstract: The electrosurgical systems and methods of the present disclosure perform cable compensation using an electrosurgical generator that includes a plurality of sensors configured to sense voltage and current waveforms, a plurality of medium-band filters, a plurality of narrowband filters, and a signal processor. The plurality of medium-band filters and narrowband filters pass sensed voltage and current waveforms at a plurality of predetermined frequencies. The signal processor calculates medium-band RMS voltage and current values using the output from the plurality of medium-band filters, calculates narrowband phase and magnitude values using the output from the plurality of narrowband filters, calculates tissue impedance based on the medium-band RMS voltage and current values and the narrowband phase value, and generates a control signal to control the energy generated by the electrosurgical generator based on the calculated tissue impedance.

Abstract: A surgical device includes an elongated shaft having an end-effector assembly at a distal end thereof. The end-effector assembly includes movable first, second and third jaw members. The first and second jaw members controllably movable from a first position, wherein the first and second jaw members are disposed in spaced relation relative to the third jaw member disposed therebetween, to a second position, wherein the first, second and third jaw members cooperate to grasp tissue therebetween.

Abstract: A surgical device includes an elongated shaft having an end-effector assembly at a distal end thereof. The end-effector assembly includes first, second and third jaw members. The first and second jaw members controllably movable from a first position, wherein the first and second jaw members are disposed in spaced relation relative to the third jaw member disposed therebetween, to a second position, wherein the first, second and third jaw members cooperate to grasp tissue therebetween. The surgical device also includes a knife operatively coupled to the elongated shaft. A channel defined along a length of an upper surface of the third jaw member is configured to slideably receive a portion of the knife therein.

Abstract: A method of cutting tissue includes providing a surgical instrument including an end-effector assembly including first and second jaw members controllably movable from a first position in spaced relation relative to a third jaw member disposed therebetween to at least one second position closer to the third jaw member wherein the first, second and third jaw members cooperate to grasp tissue therebetween. Each of the first and second jaw members includes an electrically-conductive sealing plate. A cutting member is disposed on a portion of the upper surface of the third jaw member. The method also includes positioning the first, second and third jaw members about tissue, applying energy to the electrically-conductive sealing plates so that energy passes between the electrically-conductive sealing plates and through tissue to effect a tissue seal, and activating the cutting member to cut through tissue overlying the upper surface of the third jaw member.

Abstract: The electrosurgical systems and methods of the present disclosure include a tissue resistance measurement system that compensates for capacitive parasitics in a cable connecting an electrosurgical generator to and electrosurgical cable to estimate the real resistance of a tissue load. The electrosurgical generator includes an output stage coupled to an electrical energy source and generates electrosurgical energy. The electrosurgical generator includes a plurality of sensors sensing a voltage and current of the electrosurgical energy and a controller controlling the output stage. The controller includes a calculator that calculates a real part of an impedance based on the sensed voltage and current, an estimator that estimates a resistance of the tissue using a solution to a quadratic equation that is a function of the real part of the impedance, and a control signal generator configured to generate a control signal for the output stage based on the resistance of the tissue.

Abstract: The electrosurgical systems and methods of the present disclosure include a tissue resistance measurement system that compensates for capacitive parasitics in a cable connecting an electrosurgical generator to and electrosurgical cable to estimate the real resistance of a tissue load. The electrosurgical generator includes an output stage coupled to an electrical energy source and generates electrosurgical energy. The electrosurgical generator includes a plurality of sensors sensing a voltage and current of the electrosurgical energy and a controller controlling the output stage. The controller includes a calculator that calculates a real part of an impedance based on the sensed voltage and current, an estimator that estimates a resistance of the tissue using a solution to a quadratic equation that is a function of the real part of the impedance, and a control signal generator configured to generate a control signal for the output stage based on the resistance of the tissue.

Abstract: An electrosurgical generator and related systems and methods using a gain-compensated full bridge topology. Gain nonlinearity is corrected by applying impedance and phase correction factors to a control loop to achieve a linear gain structure. In embodiments, gain compensation is performed by comparing an RF setpoint signal with a calculated output signal to generate a first error signal. An impedance correction factor is applied to the first error signal to generate a second error signal. The second error signal is processed by a proportional-integral-derivative controller to generate a phase control signal. A phase control correction factor is applied to the phase control signal to generate a corrected pulse width modulation driving signal, which is used to generate PWM driving signals for a full-bridge inverter. One or more sensors provide feedback for comparison with the RF setpoint.

Abstract: An electrosurgical forceps is provided and includes a housing, a shaft and a pair of opposing first and second jaw members. Each jaw member including a pair of spaced apart, electrically conductive tissue sealing surfaces adapted to connect to a source of electrosurgical energy such that the tissue sealing surfaces are capable of conducting electrosurgical energy through tissue held therebetween to effect a seal. One or both of the first and second jaw members includes an electrically conductive cutting element disposed thereon. A switch assembly operably disposed on the housing includes an activation member in operable communication with the source of electrosurgical energy for supplying electrosurgical energy to the first and second jaw members. Activation of the activation member provides electrosurgical energy to the tissue sealing surfaces for sealing tissue and electrosurgical energy to the cutting element for cutting the sealed tissue.

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.