A DC-to-DC voltage regulator circuit comprising: an output node; a pull-up switch and a pull-down switch with an output node coupled between them; a reactive circuit element coupled to the output node; a pull-up setting voltage circuit coupled to provide a pull-up setting voltage that is a function of a voltage at the output node; a pull-down setting voltage circuit coupled to provide a pull-down setting voltage that is a function of the voltage at the output node; a first comparator coupled to cause the pull-up switch to transition between open switch state and its closed switch state based upon a comparison of the pull-up setting voltage and a control voltage; and a second comparator coupled to cause the pull-down switch to transition between its open switch state and its closed switch state.

The present disclosure relates generally to the use of medical devices for the treatment of chronic venous disease and collagenous scar tissue. In particular, the present disclosure provides methods and systems for remodeling a collagen obstruction using energy and an expandable catheter.

A surgical instrument comprising an end effector is disclosed. The end effector comprises a surgical dissector. The surgical dissector can apply mechanical and/or electrosurgical energy to treated tissue.

Embodiments relate to circuitry to provide amplitude modulated waveforms in electrosurgical devices. The circuitry can be included in an electrosurgical generator device to provide the amplitude modulated waveforms to an electrosurgical probe coupled with the electrosurgical generator device.

A surgical instrument connectable to a surgical energy module that is configured to provide a first drive signal at a first frequency range for driving a first energy modality and a second drive signal at a second frequency range for driving a second energy modality is provided. The surgical instrument can comprise a surgical instrument component configured to receive power from a direct current (DC) power source, an end effector, and a circuit. The circuit can be configured to convert the first electrical signal to a DC voltage, apply the DC voltage to the surgical instrument component, and deliver the second energy modality to the end effector according to the second drive signal. Alternatively, the circuit can be disposed within a cable assembly configured to connect the surgical instrument to the surgical energy module.

An electrosurgical system is provided and includes a bipolar electrosurgical instrument and an electrosurgical generator. The bipolar electrosurgical instrument is arranged to seal and cut tissue captured between jaws of the bipolar electrosurgical instrument. The electrosurgical generator is arranged to supply RF energy through the bipolar electrosurgical instrument, monitor the supplied RF energy, and adjust or terminate the supplied RF energy to optimally seal the tissue.

A method and device for controlling a treatment procedure includes a treatment tool, an energy source, and a controller. The controller controls the energy source such that in a first treatment phase, power fed into the material to be treated is controlled with an increasing course. An impedance detector determines the impedance course and/or the present impedance of the material to be treated, and recognizes the achievement of an impedance minimum. A timer is started upon recognition of an impedance minimum, and upon recognition of a further impedance minimum within the specific time interval, the timer is reset. If no new impedance minimum is detected within the specific time interval and the time interval expires, the controller switches the power control to constant power or to a power course with an altered gradient. Upon fulfilling a specific criterion, there is a switchover from power control to voltage control.

A catheter for tissue ablation with one or more electrodes attached to the inner surface of the catheter body facing the lumen, and one or more electrodes attached to the outer surface. The electrodes are offset from the distal end of the catheter. The material between the inner and outer electrodes is an insulator and may be for example a dielectric with a high dielectric constant. This catheter configuration generates an electric field that bends around the tip of the catheter. The field strength near the catheter tip is relatively symmetric; therefore, tissue ablation depth is relatively insensitive to catheter orientation. Embodiments may have multiple inner or outer electrodes and may switch voltage configurations across electrodes to vary the electric field direction over time, improving ablation consistency.

A medical apparatus includes a probe configured for insertion into a body of a patient. The probe includes a plurality of electrodes configured to contact tissue within the body. The medical apparatus further includes an electrical signal generator configured to apply between one or more pairs of the electrodes signals of first and second types in alternation. The signals of the first type include a sequence of bipolar pulses having an amplitude sufficient to cause irreversible electrophoresis (IRE) in the tissue contacted by the electrodes. The signals of the second type include a radio-frequency (RF) signal having a power sufficient to thermally ablate the tissue contacted by the electrodes.

Electrosurgical coagulation devices. At least some of the example embodiment are methods including: applying RF energy between a first electrode and a second electrode, the first and second electrodes define an interstice; flowing an electrically conductive fluid through a first nozzle and a second nozzle of the first electrode, the first nozzle defines a first spray direction, the second nozzle defines a second spray direction, and a first angle between the first spray direction and the second spray direction is 180 angular degrees or less measured through the interstice; flowing an electrically conductive fluid through a third nozzle and a fourth nozzle of the second electrode, the third nozzle defines a third spray direction, the fourth nozzle defines a fourth spray direction, and a second angle between the third spray direction and the fourth spray direction is 180 angular degrees or less measured through the interstice.