Patents by Inventor James W. McPherson

James W. McPherson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20090234353
    Abstract: An electrosurgical system includes an electrosurgical generator, a capacitive return pad, a phase detection component, and a control component. The electrosurgical generator is configured to generate electrosurgical energy. The capacitive return pad has at least one capacitive return electrode operatively coupled to the electrosurgical generator and is configured to provide a return path for the electrosurgical energy. The phase detection component is configured to determine a phase difference between the current and the voltage of the electrosurgical energy. The control component is in operative communication with the phase detection component and is configured to receive the determined phase difference from the phase detection component. The control component is configured to detect a fault in the capacitive return pad by utilizing the determined phase difference.
    Type: Application
    Filed: March 10, 2009
    Publication date: September 17, 2009
    Inventor: James W. McPherson
  • Patent number: 7553309
    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.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: June 30, 2009
    Assignee: Covidien AG
    Inventors: Steven P. Buysse, Gary Dobbins, Brandon Gay, David N. Heard, James W. McPherson
  • Publication number: 20090054891
    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.
    Type: Application
    Filed: August 29, 2008
    Publication date: February 26, 2009
    Inventors: Steven P. Buysse, Gary Dobbins, Brandon Gay, David N. Heard, James W. McPherson
  • Publication number: 20080287791
    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.
    Type: Application
    Filed: June 27, 2008
    Publication date: November 20, 2008
    Inventors: James H. Orszulak, James W. McPherson
  • Publication number: 20080287838
    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.
    Type: Application
    Filed: June 27, 2008
    Publication date: November 20, 2008
    Inventors: James H. Orszulak, James W. McPherson
  • Publication number: 20080249523
    Abstract: An electrosurgical system including a generator configured to supply radiofrequency (RF) energy is disclosed. The system includes at least two electrodes configured to apply RF energy to tissue and at least one return electrode for returning the RF energy to the generator. The generator may operate in a first operational mode and at least one other operational mode. The system includes a controller configured to control the application of RF energy to each of the two or more electrodes and the return of RF energy to the generator. The controller includes a plurality of switching components configured to selectively switch the flow of the RF energy between the two or more electrodes and between the return electrode and at least one of the two or more electrodes based on the operational mode of the generator.
    Type: Application
    Filed: April 3, 2007
    Publication date: October 9, 2008
    Inventors: James W. McPherson, Lewis Puterbaugh
  • Patent number: 7396336
    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.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: July 8, 2008
    Assignee: Sherwood Services AG
    Inventors: James H. Orszulak, James W. McPherson
  • Publication number: 20080082094
    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.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 3, 2008
    Inventors: James W. McPherson, Lewis Puterbaugh
  • Publication number: 20080082092
    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.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 3, 2008
    Inventor: James W. McPherson
  • Publication number: 20080082097
    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.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 3, 2008
    Inventor: James W. McPherson
  • Patent number: 7282049
    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.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: October 16, 2007
    Assignee: Sherwood Services AG
    Inventors: James H. Orszulak, James W. McPherson