A frequency control method and system for an ultrasonic surgical tool. The frequency control method for an ultrasonic tool comprised: obtaining a maximum value of a phase difference between an operating voltage and an operating current of the ultrasonic surgical tool; determining whether the maximum value is less than zero, so as to obtain a first determination result; if the first determination result indicates that the maximum value is not less than zero, adjusting an operating frequency of the ultrasonic surgical tool to a frequency corresponding to the phase difference to zero; if the first determination result indicates that the maximum value is less than zero, subtracting a preset value from the maximum value to obtain a phase lock point; and adjusting, according to the phase lock point, the operating frequency of the ultrasonic tool. The frequency control method for an ultrasonic surgical tool solves a problem in which, in some situations where the phase of a self-resonant frequency does not exceed 0, ultrasonic surgical tools fail to operate normally, or operate inefficiently, thereby improving operation efficiency and stability of ultrasonic surgical tools.

Retrieval of material from vessel lumens can be improved by electrically enhancing attachment of the material to the thrombectomy system. The system can include a catheter having a distal portion configured to be positioned adjacent to a thrombus in a blood vessel, an electrode disposed at the distal portion of the catheter, and an interventional element configured to be delivered through a lumen of the catheter. The electrode and the interventional element are each configured to be electrically coupled to an extracorporeal current generator. Delivery of current to the interventional element can be gradually ramped up during initialization to improve patient comfort and safety.

An electrical conductor, such as a wire or catheter, which is coated circumferentially with a ferromagnetic material in a selected region, is fed from a high frequency alternating current source. The ferromagnetic material has a quick response in heating and cooling to the controllable power delivery. The ferromagnetic material can be used for separating tissue, coagulation, tissue destruction or achieving other desired tissue effects in numerous surgical procedures.

An electrosurgical generator includes: a power supply configured to output a direct current; an energy metering stage including at least one metering switching component operated by a metering switching waveform, the energy metering stage configured to generate a metered energy packet from the direct current; a power converter coupled to the energy metering stage, the power converter including at least one power switching element operated by a power switching waveform, the power converter configured to generate a radio frequency half cycle based on the metered energy packet; and a controller coupled to the power converter, the controller is configured to modulate the metering switching waveform and the power switching waveform.

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.

An electrosurgical connection unit for a surgical robot arm to connect an electrosurgical instrument attached to the arm to an electrosurgical generator. The electrosurgical connection unit includes an input port connectable to the electrosurgical generator, the input port configured to receive a driving electrosurgical signal and output one or more activation signals; an output port connectable to the electrosurgical instrument, the output port configured to output the driving electrosurgical signal received on the input port; one or more activation switch units, wherein activation of an activation switch unit causes an activation signal to be output from the input port indicating a driving electrosurgical signal with a desired waveform is to be activated; and a control unit configured to selectively activate one of the one or more activation switch units in response to a control signal.

Retrieval of material from vessel lumens can be improved by electrically enhancing attachment of the material to the thrombectomy system. The system can include a catheter having a distal portion configured to be positioned adjacent to a thrombus in a blood vessel, an electrode disposed at the distal portion of the catheter, and an interventional element configured to be delivered through a lumen of the catheter. The electrode and the interventional element are each configured to be electrically coupled to an extracorporeal power supply.

Retrieval of material from vessel lumens can be improved by electrically enhancing attachment of the material to the thrombectomy system. The system can include a catheter having a distal portion configured to be positioned adjacent to a thrombus in a blood vessel, an electrode disposed at the distal portion of the catheter, and an interventional element configured to be delivered through a lumen of the catheter. The electrode and the interventional element are each configured to be electrically coupled to an extracorporeal power supply.

Retrieval of material from vessel lumens can be improved by electrically enhancing attachment of the material to the thrombectomy system. The system can include a catheter having a distal portion configured to be positioned adjacent to a thrombus in a blood vessel, an electrode disposed at the distal portion of the catheter, and an interventional element configured to be delivered through a lumen of the catheter. The electrode and the interventional element are each configured to be electrically coupled to an extracorporeal power supply.

Retrieval of material from vessel lumens can be improved by electrically enhancing attachment of the material to the thrombectomy system. The system can include a catheter having a distal portion configured to be positioned adjacent to a thrombus in a blood vessel, an electrode disposed at the distal portion of the catheter, and an interventional element configured to be delivered through a lumen of the catheter. The electrode and the interventional element are each configured to be electrically coupled to an extracorporeal power supply.