An electrosurgical system can include an electrosurgical generator, a feedback circuit or controller, and an electrosurgical tool. The feedback circuit can provide an electrosurgery endpoint by determining the phase end point of a tissue to be treated. The electrosurgical system can include more than one electrosurgical tool for different electrosurgical operations and can include a variety of user interface features and audio/visual performance indicators. The electrosurgical system can also power conventional bipolar electrosurgical tools and direct current surgical appliances.

Various systems and methods for controlling an ultrasonic surgical instrument according to the location of tissue grasped within an end effector are disclosed. A control circuit can be configured to apply varying power levels, via a generator, to an ultrasonic transducer driving an ultrasonic electromechanical system to oscillate an ultrasonic blade. Further, the control circuit can measure impedances of the ultrasonic transducer corresponding to the varying power levels and determine a location of tissue positioned within the end effector according to a difference between the impedances of the ultrasonic transducer relative to a threshold.

An ultrasonic electromechanical system for an ultrasonic electromechanical system may include an ultrasonic blade, a clamp arm disposed opposite the ultrasonic blade, an ultrasonic transducer acoustically coupled to the ultrasonic blade, in which the ultrasonic transducer is configured to oscillate the ultrasonic blade in response to a drive signal, and a control circuit coupled to the ultrasonic transducer. The control circuit can be configured to determine a position of a tissue clamped between the ultrasonic blade and the clamp arm, and control an amount of power of the drive signal based at least in part on the position of the tissue.

A sine wave generator includes a resonator circuit, a control circuit and a pulse generator. The resonator circuit is configured to receive energy pulses and to generate a resonator sinusoidal signal responsively to the energy pulses. The control circuit is configured to estimate a signal measure of the resonator sinusoidal signal, or of a signal derived from the resonator sinusoidal signal. The pulse generator is configured to generate the energy pulses responsive to the signal measure estimated by the control circuit, and to drive the resonator circuit with the energy pulses.

An electrosurgical instrument includes jaws having an electrode configuration utilized to electrically modify tissue in contact with one or more electrodes. The instrument is removably connectable to an electrosurgical unit via an electrosurgical connector extending from the instrument and a receptacle on the electrosurgical unit. The electrosurgical instrument is rotatable without disrupting electrical connection to the electrodes of the jaws. One or more of the electrodes is retractable. The electrosurgical unit and instrument optimally seals and/or cuts tissue based on identifying the tissue and monitoring the modification of the tissue by the application of radio frequency energy.

A control system for use with an electrosurgical generator which delivers electrosurgical energy to tissue has a control module. The module includes a processor executing an algorithm. The algorithm has the steps of determining a sensed voltage value corresponding to a sensed voltage signal output by the electrosurgical generator and determining a sensed current value corresponding to a sensed current signal output by the electrosurgical generator. The algorithm has the steps of determining phase information corresponding to a phase shift between the voltage signal and the current signal and determining a characteristic related to the electrosurgical energy delivered to the tissue using the phase information, the sensed voltage value and the sensed current value.

A radio-frequency (RF) amplifier having a direct response to an arbitrary signal source to output one or more electrosurgical waveforms within an energy activation request, is disclosed. The RF amplifier includes a phase compensator coupled to an RF arbitrary source, the phase compensator configured to generate a reference signal as a function of an arbitrary RF signal from the RF arbitrary source and a phase control signal; at least one error correction amplifier coupled to the phase compensator, the at least one error correction amplifier configured to output a control signal at least as a function of the reference signal; and at least one power component coupled to the at least one error correction amplifier and to a high voltage power source configured to supply high voltage direct current thereto, the at least one power component configured to operate in response to the control signal to generate at least one component of the at least one electrosurgical waveform.

An apparatus is provided to detect electrical contact between anatomical tissue and a shield conductor: a transformer; an alternating current (AC) reference frequency signal generator to inject a reference frequency signal to a primary winding of the transformer; a reactive impedance coupled in parallel with a secondary winding of the transformer between a first node and a second node; and a phase match detector circuit to detect a phase match between the reference frequency signal and a reflected reference frequency signal that is reflected from the secondary winding to the primary winding.

An ultrasonic electromechanical system for an ultrasonic surgical instrument may include an ultrasonic blade, a clamp arm disposed opposite the ultrasonic blade, an ultrasonic transducer configured to oscillate the ultrasonic blade in response to a drive signal, and a control circuit coupled to the ultrasonic transducer. The control circuit can be configured to determine a temperature of the ultrasonic blade, increase an amount of power of the drive signal when the temperature of the ultrasonic blade is less than a first predetermined value, and decrease the amount of power of the drive signal when the temperature of the ultrasonic blade is greater than a second predetermined value. The second predetermined value may be greater than the first predetermined value. An ultrasonic generator connectable to the ultrasonic electromechanical system may include the control circuit.

Electrode assemblies include segmented electrodes disposed on a catheter. The segmented electrodes can be constructed at the tip of the catheter. Tip electrodes can be constructed from an electrically insulative substrate comprising an inner lumen, an external tip surface, and a plurality of channels extending from the inner lumen to the external tip surface, a plurality of segmented electrodes, and a plurality of spot electrodes. Each of the plurality of segmented electrodes and each of the plurality of spot electrodes can be laterally separated from each other by an electrically non-conductive substrate portion and each of the spot electrodes and each of the segmented electrodes can be electrically coupled to at least one wire or conductor trace.