Systems and methods for monitoring return patch impedances are provided. A tissue therapy system includes a catheter comprising at least one electrode, the catheter implantable in a patient, a first return patch electrode configured to be applied to skin of the patient, a second return patch electrode configured to be applied to the skin of the patient, and an impedance measuring circuit lectrically coupled to the at least one catheter electrode, the first return patch electrode, and the second return patch electrode. The impedance measuring circuit is configured to drive currents between the at least one catheter electrode, the first return patch electrode, and the second return patch electrode, detect, using a voltage at the at least one catheter electrode as a reference voltage, voltages generated in response to the driven currents, and measure impedances based on the driven currents and the detected voltages.

An electrosurgery system includes a first generator configured to output an operating signal. The system also includes a pathway for the operating signal, the pathway includes an active electrode and a patient pad. The system also includes a circuit configured to measure a complex impedance of the patient pad. The circuit includes a second generator configured to output a measuring signal. The system also includes a voltage transformer, a current transformer, and a plurality of filters.

An electrosurgery system includes a first generator configured to output an operating signal. The system also includes a pathway for the operating signal, the pathway includes an active electrode and a patient pad. The system also includes a circuit configured to measure a complex impedance of the patient pad. The circuit includes a second generator configured to output a measuring signal. The system also includes a voltage transformer, a current transformer, and a plurality of filters.

The present invention relates to systems for use for radio frequency ablation. The systems can include one or more of an ablation tool, power source for use with the ablation tool and a backstop for use in conjunction with the ablation tool during surgical procedures. Preferred ablation tools comprise a series of three or more blade-shaped electrodes disposed in a linear, curved, curvilinear or circular array. The backstops are useful for reducing direct physical and thermal heat transfer injuries to the patient or surgeon during procedures using radiofrequency (RF) ablation devices.

Methods and systems provide a body surface electrode, such as a patch, and, for example, a backpatch, which automatically detects detachment from the skin and/or proximity thereto, within a predetermined limit, and hence, the electrode coming out of contact with and/or proximity to the skin. Once the detachment is detected, the disclosed system instantaneously terminates pulse delivery to a pulse delivery electrode from an IRE generator, which generates the delivered pulses. By instantaneously terminating pulse delivery, damage to body tissues from overheating caused by pulses is minimized or eliminated.

Methods and systems provide a body surface electrode, such as a patch, and, for example, a backpatch, which automatically detects detachment from the skin and/or proximity thereto, within a predetermined limit, and hence, the electrode coming out of contact with and/or proximity to the skin. Once the detachment is detected, the disclosed system instantaneously terminates pulse delivery to a pulse delivery electrode from an IRE generator, which generates the delivered pulses. By instantaneously terminating pulse delivery, damage to body tissues from overheating caused by pulses is minimized or eliminated.

The present disclosed subject matter provides a return electrode, such as a body surface electrode, which includes an accelerometer, for detecting movement of the body at and proximate to the location of the return electrode. The body movement results from pulses from an Irreversible Electroporation (IRE) pulse generator which are delivered to the return electrode, by a pulse delivery electrode. The data associated with the body movement at each location on the body of the return electrode, is used to determine suitable, and in some cases optimal, locations for return electrodes for IRE procedures.

The present disclosed subject matter provides a return electrode, such as a body surface electrode, which includes an accelerometer, for detecting movement of the body at and proximate to the location of the return electrode. The body movement results from pulses from an Irreversible Electroporation (IRE) pulse generator which are delivered to the return electrode, by a pulse delivery electrode. The data associated with the body movement at each location on the body of the return electrode, is used to determine suitable, and in some cases optimal, locations for return electrodes for IRE procedures.

An electrosurgical generator includes: a power supply configured to output a direct current; a current source coupled to the power supply and configured to output source current based on the direct current, and a power converter coupled to the current source, the power converter including at least one power switching element operated at a switching waveform. The power converter is configured to generate a converted waveform based on the source current. The electrosurgical generator also includes a controller coupled to the power converter and configured to modulate the switching waveform and a snubber circuit coupled to the current source and the power converter. The snubber circuit is configured to return the voltage at the at least one power switching element to zero after the power converter generates at least a portion of the converted waveform.

An electrosurgical generator includes: a power supply configured to output a direct current; a current source coupled to the power supply and configured to output source current based on the direct current, and a power converter coupled to the current source, the power converter including at least one power switching element operated at a switching waveform. The power converter is configured to generate a converted waveform based on the source current. The electrosurgical generator also includes a controller coupled to the power converter and configured to modulate the switching waveform and a snubber circuit coupled to the current source and the power converter. The snubber circuit is configured to return the voltage at the at least one power switching element to zero after the power converter generates at least a portion of the converted waveform.