Abstract: A method for performing an electrosurgical procedure at a surgical site on a patient, the method including the steps of providing a current restricting circuit operatively coupled between a source of electro surgical energy and an electrode, the current restricting circuit including: a switch configured to direct the flow of electrosurgical energy; and a plurality of current restrictive devices arranged in an H-Bridge arrangement, wherein the switch is disposed between adjacent current restrictive devices of the plurality of current restrictive devices; restricting the flow of electrosurgical energy wherein the current restricting circuit is configured to restrict a flow of electrosurgical energy when the switch is in a first position; enabling the flow of electrosurgical energy when the switch is in a second position; and dynamically controlling the electrosurgical energy delivered to the electrode with the current restricting circuit.

Abstract: An electrosurgical system is disclosed. The electrosurgical system includes a multiple-secondary transformer configured for sensing voltage. The multiple-secondary transformer includes a primary winding coupled to an active terminal and a return terminal of the electrosurgical system and a plurality of secondary windings. Each of the secondary windings is configured to transform the radio frequency voltage into a sensed voltage. Each of the secondary windings includes an output coupled to a sensor circuit and configured to transmit the sensed voltage to the sensor circuit.

Abstract: An electrosurgical return electrode is disclosed. The return electrode includes a conductive pad having one or more temperature monitoring zones and a patient-contacting surface configured to conduct electrosurgical energy and a temperature sensing circuit coupled to the conductive pad. The temperature sensing circuit includes at least one diode disposed within the at least one temperature monitoring zone, the at least one diode having a predetermined forward voltage drop that is indicative of temperature of at least one temperature monitoring zone.

Abstract: A system for heat ablation of tissue in a patient comprises a plurality of electrodes operatively connected to a source of radiofrequency energy and configured to apply RF energy to tissue at a patient site, a plurality of RF current restricting circuits, each circuit coupled between one of the plurality of electrodes and the source of radiofrequency energy, and configured to restrict RF energy to the electrode when the current restricting circuit is enabled and not restrict RF energy to flow to the electrode when the current restricting circuit is disabled, at least one return electrode adapted to contact the patient and configured to return RF energy to the RF source; and a switching mechanism configured to selectively enable each of the plurality of RF current restricting circuits, in one of a sequential and non sequential fashion, wherein the switching mechanism is isolated from each of the current restricting circuits.

Abstract: A switched resonant power amplifier system for ultrasonic transducers is disclosed. The system includes an amplifier that receives and processes a driver output signal for generating a drive signal that is provided to an ultrasonic device for controlling output of the ultrasonic device. An output control circuit receives and processes a signal related to a feedback signal generated by the ultrasonic device and a divider reference signal, and generates a compensated clock signal that is adjusted for at least one of phase and frequency differences between the received feedback signal and the divider reference signal. A compensated drive circuit receives and processes the compensated clock signal for generating the divider reference signal, and for generating the driver output signal.

Abstract: A system for heat ablation of tissue, the system comprising a radiofrequency source configured to supply RF energy to at least two electrodes for treating tissue, at least one return electrode configured to return the RF energy to the radiofrequency source, a controller configured to sequentially apply the RF energy to each of the at least two electrodes for a pre-determinable period of time and circuitry configured to switch the RF energy to an internal load. The RF energy is applied simultaneously to the internal load and at least one of the at least two electrodes. The controller is configured to apply the RF energy to the next electrode in the sequence when the amount of time the applied RF energy is off is greater than a predetermined minimum off time.

Abstract: A switched resonant power amplifier system for ultrasonic transducers is disclosed. The system includes an amplifier that receives and processes a driver output signal for generating a drive signal that is provided to an ultrasonic device for controlling output of the ultrasonic device. An output control circuit receives and processes a signal related to a feedback signal generated by the ultrasonic device and a divider reference signal, and generates a compensated clock signal that is adjusted for at least one of phase and frequency differences between the received feedback signal and the divider reference signal. A compensated drive circuit receives and processes the compensated clock signal for generating the divider reference signal, and for generating the driver output signal.

Abstract: A switched resonant power amplifier system for ultrasonic transducers is disclosed. The system includes an amplifier that receives and processes a driver output signal for generating a drive signal that is provided to an ultrasonic device for controlling output of the ultrasonic device. An output control circuit receives and processes a signal related to a feedback signal generated by the ultrasonic device and a divider reference signal, and generates a compensated clock signal that is adjusted for at least one of phase and frequency differences between the received feedback signal and the divider reference signal. A compensated drive circuit receives and processes the compensated clock signal for generating the divider reference signal, and for generating the driver output signal.

Abstract: A system for heat ablation of tissue in which energy is sequentially applied to at least two electrodes inserted into tissue, the system comprising a radiofrequency source configured to supply radiofrequency energy to two or more electrodes, at least one return electrode for returning the RF energy to the RF source, and a controller configured to sequentially apply the RF energy to each of the two or more electrodes for a predetermined period of time. The controller includes a determiner configured to determine an off time for a next electrode in a sequence and a comparator configured to compare the off time for the next electrode in the sequence to a predetermined minimum off time. The controller applies the radiofrequency energy to the next electrode in the sequence when the off time is greater than the predetermined minimum off time.

Abstract: An electrosurgical return electrode is disclosed. The return electrode includes a return electrode pad having a patient-contacting surface configured to conduct electrosurgical energy and a sensor circuit coupled to the return electrode pad. The sensor circuit is configured to monitor at least one of a return electrode pad property and a tissue property to generate sensor data. The return electrode also includes a control circuit coupled to the return electrode pad and to the sensor circuit. The control circuits configured to receive and process sensor data from the sensor circuit and relay the processed sensor data to an electrosurgical energy source.

Abstract: An electrosurgical return electrode is disclosed. The return electrode includes a conductive pad having one or more temperature monitoring zones and a patient-contacting surface configured to conduct electrosurgical energy and a temperature sensing circuit coupled to the conductive pad. The temperature sensing circuit includes at least one diode disposed within the at least one temperature monitoring zone, the at least one diode having a predetermined forward voltage drop that is indicative of temperature of at least one temperature monitoring zone.

Abstract: An electrosurgical return electrode is disclosed. The return electrode includes a conductive pad having one or more temperature monitoring zones and a patient-contacting surface configured to conduct electrosurgical energy and a temperature sensing circuit coupled to the conductive pad. The temperature sensing circuit includes at least one diode disposed within the at least one temperature monitoring zone, the at least one diode having a predetermined forward voltage drop that is indicative of temperature of at least one temperature monitoring zone.

Abstract: An electrosurgical system is disclosed. The electrosurgical system includes a multiple-secondary transformer configured for sensing voltage. The multiple-secondary transformer includes a primary winding coupled to an active terminal and a return terminal of the electrosurgical system and a plurality of secondary windings. Each of the secondary windings is configured to transform the radio frequency voltage into a sensed voltage. Each of the secondary windings includes an output coupled to a sensor circuit and configured to transmit the sensed voltage to the sensor circuit.

Abstract: An electrosurgical system is disclosed. The electrosurgical system includes a multiple-secondary transformer configured for sensing voltage. The multiple-secondary transformer includes a primary winding coupled to an active terminal and a return terminal of the electrosurgical system and a plurality of secondary windings. Each of the secondary windings is configured to transform the radio frequency voltage into a sensed voltage. Each of the secondary windings includes an output coupled to a sensor circuit and configured to transmit the sensed voltage to the sensor circuit.

Abstract: An electrosurgical return electrode is disclosed. The return electrode includes a return electrode pad having a patient-contacting surface configured to conduct electrosurgical energy and a sensor circuit coupled to the return electrode pad. The sensor circuit is configured to monitor at least one of a return electrode pad property and a tissue property to generate sensor data. The return electrode also includes a control circuit coupled to the return electrode pad and to the sensor circuit. The control circuits configured to receive and process sensor data from the sensor circuit and relay the processed sensor data to an electrosurgical energy source.

Abstract: A system for heat ablation of tissue in which energy is sequentially applied to at least two electrodes inserted into tissue, the system comprising a radiofrequency source configured to supply radiofrequency energy to two or more electrodes, at least one return electrode for returning the RF energy to the RF source, and a controller configured to sequentially apply the RF energy to each of the two or more electrodes for a predetermined period of time. The controller includes a determiner configured to determine an off time for a next electrode in a sequence and a comparator configured to compare the off time for the next electrode in the sequence to a predetermined minimum off time. The controller applies the radiofrequency energy to the next electrode in the sequence when the off time is greater than the predetermined minimum off time.

Abstract: The present disclosure provides an electrosurgical return pad current detection system for use in monopolar surgery as well as a method of using the same. The detection system comprises a plurality of conductive pads which include a plurality of conductive elements. The detection system further includes a sensor which senses the current returning to each conductive pad as well as a comparator which determines the difference in current among a plurality of conductive pads. If the current differential is above or below a prescribed limit, the system will alert the user of potential hazards and/or alter the amount of energy delivered to a surgical device.

Abstract: An electrosurgical return electrode is disclosed. The return electrode includes a return electrode pad having a patient-contacting surface configured to conduct electrosurgical energy and a sensor circuit coupled to the return electrode pad. The sensor circuit is configured to monitor at least one of a return electrode pad property and a tissue property to generate sensor data. The return electrode also includes a control circuit coupled to the return electrode pad and to the sensor circuit. The control circuits configured to receive and process sensor data from the sensor circuit and relay the processed sensor data to an electrosurgical energy source.

Abstract: A system and method for heat ablation of tissue in which energy is sequentially applied to at least two electrodes inserted into tissue. The system is comprised of a radiofrequency (RF) source for supplying RF energy, at least two electrodes configured to apply RF energy to tissue, at least one return electrode for returning the RF energy to the RF source, and a controller configured to sequentially apply the RF energy to each of the at least two electrodes. The sequential delivery of energy is determined by the measured current and voltage, the calculated impedance at each of the electrodes and the timing for each electrode. An internal load may be activated with the previously activated channel and remain on until the next channel is activated to avoid the generator from having an open circuit.

Abstract: An electrosurgical generator is disclosed. The electrosurgical generator includes a power supply for generating a DC voltage. The electrosurgical generator also includes a first parallel inductor-capacitor circuit being driven by a first signal at a first predetermined frequency and a second parallel inductor-capacitor inductor-capacitor circuit driven by a second signal at the first predetermined frequency phase shifted 180°. The electrosurgical generator further includes a series inductor-capacitor resonant circuit operably connected in series with a primary winding of a transformer. The first and second parallel inductor-capacitor circuits are operably connected to the transformer, such that the first inductor-capacitor circuit generates a positive half sine wave and the second inductor-capacitor circuit generates a 180° phase-shifted positive half sine wave to generate a full sine wave in a secondary winding of the transformer.