A system and method for detecting faults within an electrosurgical instrument having a shield and an active electrode uses multiple possible fault conditions. In one embodiment the monitoring system comprises an electrosurgical generator coupled to the electrosurgical instrument and adapted to deliver power to the active electrode of the electrosurgical instrument, monitoring circuitry coupled to the electrosurgical generator and the electrosurgical instrument.

An electrosurgical generator includes: a power supply configured to output a DC waveform; a current or voltage source coupled to the power supply and configured to output current; and a power converter coupled to the current source. The power converter includes at least one power switching element operated at a switching waveform and configured to generate a radio frequency waveform based on the energy from the current or voltage source. The radio frequency waveform includes at least one pulse having an overshoot peak. The electrosurgical generator further includes a clipper circuit coupled to the current source and the power converter, the clipper circuit configured to generate a clipping voltage to clip the overshoot peak; and a controller coupled to the power converter and configured to modulate the switching waveform to generate the radio frequency waveform.

At least some embodiments of the present disclosure are directed to an electroporation ablation system for treating targeted tissue in a patient. The electroporation ablation system comprises an ablation catheter including catheter electrodes configured to generate electric fields in the targeted tissue in response to a plurality of electrical pulse sequences delivered in a plurality of therapy sections; a controller configured to receive a first pulse voltage of a first electrical pulse sequence measured during a first therapy section of the plurality of therapy sections; and determine a charge voltage based on the first pulse voltage; and an electroporation generator. The electroporation generator is operatively coupled to the catheter electrodes and the controller and configured to deliver a second electrical pulse sequence at a controlled pulse voltage for a second therapy section of the plurality of therapy sections.

A plurality of control-signal generators are configured to generate respective control signals having respective control-signal amplitudes and different respective control-signal frequencies, and a plurality of signal adders are configured to produce respective composite signals for application to a subject, by adding the control signals to respective ablation signals having respective ablation-signal amplitudes. The control-signal generators are configured to generate the control signals such that respective ratios between the control-signal amplitudes and the ablation-signal amplitudes are constant during the application of the composite signals to the subject. A plurality of controlled voltage dividers are configured to adjust respective amplitudes of the composite signals during the application of the composite signals to the subject, and one or more controllers are configured to control the adjusting of the amplitudes by the controlled voltage dividers, in response to respective currents of, and respective voltages of, the control signals, and based on the constant ratios.

In an example, an electrosurgical generator includes a power converter configured to convert a supply power received from a power source to an output power. The output power is suitable for delivering electrosurgical energy. The electrosurgical generator also includes a current sensor configured to sense a current of the output power and generate a logarithmic and analog representation of the current, and a voltage sensor configured to sense a voltage of the output power and generate a logarithmic and analog representation of the voltage. The electrosurgical generator further includes a controller configured to: (i) receive the logarithmic and analog representation of the current sensed by the current sensor, (ii) receive the logarithmic and analog representation of the voltage sensed by the voltage sensor, and (iii) adjust, based on the logarithmic and analog representation of the current and the voltage, a voltage

A method includes, coupling, to a target tissue, at least a pair of electrodes of an ablation catheter; at a first stage of an ablation procedure, a first bipolar signal having a first amplitude, is received from the pair of electrodes; at a second stage of the ablation procedure, a second bipolar signal having a second amplitude, is received from the pair of electrodes; based on the first and second amplitudes, at least a parameter indicative of a progress of the ablation procedure is estimated.

A method of ablating tissue with pulse field ablation energy includes generating a single pulse of energy between a first set of one or more conducting elements of a first polarity and a second set of one or more conducting elements of a second polarity, the single pulse of energy having a first pulse width and consecutively generating pulses of energy with opposite polarity to that of the single pulse of energy, the pulses having a collective pulse width equal to the first pulse width.

A device (10) for tissue coagulation, in particular for fusion, encompasses an electric source (18), which is connected or which can be connected to electrodes (12, 13) for influencing biological tissue (11) with current. A control unit (22) controls the source (18) during phases I and II of the tissue fusion. These phases I and II correspond to operating phases I, II and III of the device (10). During operating phase I, a monitoring unit (23) determines the energy E.sub.1, which is applied into the tissue (11). In the subsequent operating phases II and III, the control unit (22) controls the source (18) by means of the determined energy E.sub.1. Such a device turns out to be particularly reliable and to be robust in use.

An end effector assembly adapted to couple to an electrosurgical instrument, the end effector assembly including a plurality of spaced apart small seal plates on opposing jaw members where each seal plate forms a pair of seal plates with the corresponding seal plate on the opposing jaw member. Each pair of seal plates is individually activatable, and the pair of seal plates are activated in sequence. When the opposing jaw members are in an approximated position, the pairs of seal plates around the periphery of each jaw member define a gap therebetween that is larger than the gap between pairs of seal plates along the center of each jaw member.

A surgical instrument comprising a shiftable transmission is disclosed. The transmission comprises a mechanism for assuring that the transmission is in one of a plurality of predefined configurations.