Patents by Inventor Mark T. Stewart

Mark T. Stewart 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).

  • Patent number: 10849677
    Abstract: A system and method for the safe delivery of treatment energy to a patient, which includes verification of system integrity before, during, or after the delivery of treatment energy and provides several mechanisms for rapid termination of the delivery of potentially harmful energy to the patient when a fault condition in the device and/or system is identified. The system may include an energy generator having processing circuitry to determine if there is a fault condition in the system and to automatically terminate a delivery of treatment energy when the processing circuitry determines there is a fault condition. The method may generally include performing a series of pre-checks, synchronizing a treatment energy delivery to the proper segment of the heart's depolarization pattern, configuring the system for treatment energy delivery, delivering the treatment energy, and performing post-treatment evaluation.
    Type: Grant
    Filed: January 27, 2017
    Date of Patent: December 1, 2020
    Assignee: Medtronic, Inc.
    Inventors: Steven J. Fraasch, Catherine R. Condie, Brian T. Howard, Louis Jacob, Paul S. Lam, Trenton J. Rehberger, Mark T. Stewart, Qin Zhang
  • Publication number: 20200315703
    Abstract: Methods and systems for combining ablation therapy with navigation of the ablation device. An ablation system may be configured for use with one of two methods to prevent loss of navigation signals during ablation energy delivery. In the first method, ablation energy signals are filtered from the navigation signal. In the second method, the delivery of ablation energy is sequenced with the delivery of navigation energy such that ablation energy and navigation energy are not delivered at the same time and navigation signals received by the system are time-division multiplexed to reconstruct the navigation signals and determine a location of the device within the patient.
    Type: Application
    Filed: June 18, 2020
    Publication date: October 8, 2020
    Inventors: Marshall L. Sherman, Catherine R. Condie, Trenton J. Rehberger, Steven J. Fraasch, Mark T. Stewart
  • Publication number: 20200297418
    Abstract: A medical system, including a medical device having a plurality of deployable arms, and at least one electrode on at least one of the plurality of arms; and an electric signal generator in communication with the medical device, the electric signal generator programmed to deliver pulsed energy to the medical device sufficient to induce irreversible electroporation ablation.
    Type: Application
    Filed: June 8, 2020
    Publication date: September 24, 2020
    Inventors: Mark T. Stewart, Jordon D. Honeck
  • Patent number: 10722302
    Abstract: Methods and systems for combining ablation therapy with navigation of the ablation device. An ablation system may be configured for use with one of two methods to prevent loss of navigation signals during ablation energy delivery. In the first method, ablation energy signals are filtered from the navigation signal. In the second method, the delivery of ablation energy is sequenced with the delivery of navigation energy such that ablation energy and navigation energy are not delivered at the same time and navigation signals received by the system are time-division multiplexed to reconstruct the navigation signals and determine a location of the device within the patient.
    Type: Grant
    Filed: September 27, 2016
    Date of Patent: July 28, 2020
    Assignee: Medtronic Ablation Frontiers LLC
    Inventors: Marshall L. Sherman, Catherine R. Condie, Trenton J. Rehberger, Steven J. Fraasch, Mark T. Stewart
  • Publication number: 20200138506
    Abstract: Methods and systems for monitoring and modifying pulsed field ablation (PFA) energy delivery to prevent patient safety risks and/or delivery device failure. In particular, some embodiments provide methods and systems for detecting and preventing arcs and arc-induced plasma, and their causal events, during delivery of pulsed field ablation energy, as well as methods and systems for identifying conditions leading to potential delivery device failure and correcting charge imbalance or asymmetry.
    Type: Application
    Filed: November 7, 2019
    Publication date: May 7, 2020
    Inventors: Steven J. FRAASCH, Trenton J. REHBERGER, Qin ZHANG, Lynn A. DAVENPORT, Steven V. RAMBERG, Brian T. HOWARD, Mark T. STEWART, Alexander J. HILL, John VANDANACKER
  • Publication number: 20200121382
    Abstract: Systems and methods to confirm safe delivery of treatment energy to a patient by identifying a presence of a fault in an energy delivery pathway and identifying a location of the fault within the device. The system includes a processing unit configured to calculate blood impedances external to the device based on known impedance characteristics of the device, and then to calculate impedances within the device during energy delivery based on the calculated blood impedances. The processing unit prevents the delivery of energy in an energy delivery pathway that is determined to be compromised. The processing unit is also configured to compare times for two different frequencies to travel a predetermined distance, the difference in the times corresponding to a location of a fault within the energy delivery pathway.
    Type: Application
    Filed: December 23, 2019
    Publication date: April 23, 2020
    Inventors: Steven J. FRAASCH, Catherine R. CONDIE, Trenton J. REHBERGER, Mark T. STEWART, Qin ZHANG
  • Publication number: 20200107879
    Abstract: A method for ablating tissue by applying at least one pulse train of pulsed-field energy. The method includes delivering a pulse train of energy having a predetermined frequency to cardiac tissue, the pulse train including at least 60 pulses, an inter-phase delay between 0 ?s and 5 ?s, an inter-pulse delay of at least 5 ?s, and a pulse width of 5 ?s.
    Type: Application
    Filed: December 9, 2019
    Publication date: April 9, 2020
    Inventors: Mark T. STEWART, Steven J. FRAASCH
  • Patent number: 10589130
    Abstract: A device and method for ablating tissue is disclosed comprising the steps of acquiring an anatomical image of a patient, correlating the image to the patient, guiding an ablating member within the patient while tracking the position of the ablating member in the patient, positioning the ablating member in a desired position to ablate tissue, emitting ablating energy from the ablating member to form an ablated tissue area and removing the ablating member from the patient.
    Type: Grant
    Filed: March 12, 2018
    Date of Patent: March 17, 2020
    Assignee: MEDTRONIC, INC.
    Inventors: James B. Hissong, Mark T. Stewart, David E. Francischelli, James R. Keogh, Hotaik Lee, Nadine B. Smith, James R. Skarda
  • Patent number: 10555768
    Abstract: Systems and methods to confirm safe delivery of treatment energy to a patient by identifying a presence of a fault in an energy delivery pathway and identifying a location of the fault within the device. The system includes a processing unit configured to calculate blood impedances external to the device based on known impedance characteristics of the device, and then to calculate impedances within the device during energy delivery based on the calculated blood impedances. The processing unit prevents the delivery of energy in an energy delivery pathway that is determined to be compromised. The processing unit is also configured to compare times for two different frequencies to travel a predetermined distance, the difference in the times corresponding to a location of a fault within the energy delivery pathway.
    Type: Grant
    Filed: February 14, 2017
    Date of Patent: February 11, 2020
    Assignee: Medtronic, Inc.
    Inventors: Steven J. Fraasch, Catherine R. Condie, Trenton J. Rehberger, Mark T. Stewart, Qin Zhang
  • Patent number: 10531914
    Abstract: A method for ablating tissue by applying at least one pulse train of pulsed-field energy. The method includes delivering a pulse train of energy having a predetermined frequency to cardiac tissue, the pulse train including at least 60 pulses, an inter-phase delay between 0 ?s and 5 ?s, an inter-pulse delay of at least 5 ?s, and a pulse width of 5 ?s.
    Type: Grant
    Filed: August 4, 2016
    Date of Patent: January 14, 2020
    Assignee: Medtronic, Inc.
    Inventors: Mark T. Stewart, Steven J. Fraasch
  • Publication number: 20200009378
    Abstract: A method, system, and device for electroporation. A system may include a medical device with a plurality of electrodes borne on an expandable element and an energy generator in communication with the electrodes. The energy generator may have processing circuitry configured to selectively deliver electroporation energy to at least one of the electrodes. The processing circuitry may determine whether an alert condition is present and, if so, cease the delivery of electroporation energy to one or more electrodes identified as the cause of the alert condition and/or prevent the delivery of electroporation energy to the one or more electrodes identified as the cause of the alert condition. The energy generator may also be configured to deliver electroporation energy in a sequence of a plurality of energy delivery patterns to enhance lesion formation.
    Type: Application
    Filed: September 17, 2019
    Publication date: January 9, 2020
    Inventors: Mark T. STEWART, Brian T. HOWARD
  • Publication number: 20190254735
    Abstract: Devices, systems, and methods for more efficiently ablating tissue with pulsed field ablation energy while minimizing collateral injury to non-target tissue. In one embodiment, a system for ablating tissue at a treatment site comprises: an energy delivery device; and a control unit including: a source of impedance-modifying fluid in fluid communication with the energy delivery device; an energy generator in electrical communication with the energy delivery device, the energy generator being configured to transmit energy to the energy delivery device and the energy delivery device being configured to deliver energy to the treatment site; and processing circuitry configured to control delivery of the impedance-modifying fluid from the energy delivery device to the treatment site. In one embodiment, a method for ablating tissue comprises delivering an impedance-modifying fluid to a treatment site and delivering pulsed field ablation energy to the treatment site.
    Type: Application
    Filed: January 31, 2019
    Publication date: August 22, 2019
    Inventors: Mark T. STEWART, Brian T. HOWARD
  • Publication number: 20190223948
    Abstract: A device, system, and method for ablating tissue with pulsed field ablation energy while minimizing stimulation of skeletal muscle and nerves, as well as minimizing damage to non-targeted tissue. Some embodiments provide a device, system, and method for delivering pulsed field ablation energy to tissue from at least one energy delivery electrode on an energy delivery device to at least one energy return electrode, which may be located on the energy delivery device and/or on a sheath or secondary device. The at least one energy delivery electrode has a surface area for the application of energy that is smaller than the surface area for the receipt or return of energy of the at least one energy return electrode.
    Type: Application
    Filed: January 18, 2019
    Publication date: July 25, 2019
    Inventors: Mark T. STEWART, Brian T. HOWARD
  • Publication number: 20190216525
    Abstract: A method and system for mapping tissue and producing lesions for the treatment of cardiac arrhythmias in a non-thermal and optimal manner, minimizing the amount of energy required to selectively stun or ablate the target tissues. Energy may be delivered only at the moment(s) of best device position and proximity of an electrode to target tissue, and only during a time in the cardiac cycle determined to be optimal for reversible or irreversible effects. A method may include determining timing of the cardiac cycle and an optimal time within the cardiac cycle for energy delivery, evaluating proximity between at least one energy delivery electrode and the target tissue, and delivering pulsed field energy from the at least one energy delivery electrode to the target tissue when, during the optimal time for energy delivery, the at least one energy delivery electrode is in close proximity with the target tissue.
    Type: Application
    Filed: March 20, 2019
    Publication date: July 18, 2019
    Inventors: Mark T. STEWART, Catherine R. CONDIE, Jay L. KELLEY
  • Publication number: 20190209235
    Abstract: A medical device for directionally focusing energy to a treatment site, the medical device including a shaft having an elongated body defining a proximal portion and a distal portion opposite the proximal portion, the distal portion including at least one electrode having a contact portion and a permeable sheath at least partially surrounding the at least one electrode, the permeable sheath and the at least one electrode defining an insulation cavity, the permeable sheath being impermeable to an insulation material introduced to the insulation cavity from a fluid source configured to be coupled to the shaft.
    Type: Application
    Filed: January 8, 2019
    Publication date: July 11, 2019
    Inventors: Mark T. STEWART, Brian T. HOWARD
  • Patent number: 10335280
    Abstract: A method for treating a human patient includes emitting ultrasound energy from an ultrasound transducer positioned remotely from target tissue of the patient. The ultrasound transducer is positioned at a desired location relative to the patient and target tissue using location and imaging techniques. The method further includes focusing the ultrasound energy such that one or more focal points are directed to the target tissue of the patient and ablating the target tissue at each focal point. The target tissue is ablated via the focused ultrasound energy without ablating non-target tissue through which the ultrasound energy passes between the ultrasound transducer and the one or more focal points.
    Type: Grant
    Filed: April 14, 2016
    Date of Patent: July 2, 2019
    Assignee: Medtronic, Inc.
    Inventors: James R. Keogh, Timothy R. Ryan, Carol E. Eberhardt, Mark T. Stewart, James R. Skarda, Timothy G. Laske, Alexander J. Hill, Jack D. Lemmon, David E. Francischelli
  • Patent number: 10285755
    Abstract: A medical system, including a catheter body, an elongate body disposed in the catheter body; an expandable element having a proximal portion coupled to the catheter body and a distal portion coupled to the elongate body, the distal portion of the expandable element defining the distal-most portion of the medical device; a mesh or array of longitudinal splines substantially surrounding the expandable element, at least a portion of the mesh or splines being electrically conductive; and a coolant source in fluid communication with the expandable element.
    Type: Grant
    Filed: June 13, 2016
    Date of Patent: May 14, 2019
    Assignee: Medtronic Ablation Frontiers LLC
    Inventors: Mark T. Stewart, Jordon D. Honeck
  • Patent number: 10271893
    Abstract: A method and system for mapping tissue and producing lesions for the treatment of cardiac arrhythmias in a non-thermal and optimal manner, minimizing the amount of energy required to selectively stun or ablate the target tissues. Energy may be delivered only at the moment(s) of best device position and proximity of an electrode to target tissue, and only during a time in the cardiac cycle determined to be optimal for reversible or irreversible effects. A method may include determining timing of the cardiac cycle and an optimal time within the cardiac cycle for energy delivery, evaluating proximity between at least one energy delivery electrode and the target tissue, and delivering pulsed field energy from the at least one energy delivery electrode to the target tissue when, during the optimal time for energy delivery, the at least one energy delivery electrode is in close proximity with the target tissue.
    Type: Grant
    Filed: March 20, 2015
    Date of Patent: April 30, 2019
    Assignee: Medtronic Ablation Frontiers LLC
    Inventors: Mark T. Stewart, Catherine R. Condie, Jay L. Kelley
  • Publication number: 20190110838
    Abstract: A device, system, and method for optically evaluating and treating or ablating tissue. Specifically, device, system, and method allow for the optical and/or electrical evaluation of tissue at the same location(s) at which ablation or treatment or ablation energy is delivered. This allows for a more accurate evaluation of lesion formation and tissue condition before, during, and/or after a treatment or ablation procedure. In one embodiment, a device for performing a medical procedure includes an elongate body including a proximal portion, a distal portion having a distal end, and a longitudinal axis, and a distal tip electrode at the elongate body distal end, the tip electrode being optically transparent and electrically conductive. The device may also include optical windows in the elongate body aligned with one or more transparent lateral electrodes for optically interrogating tissue and/or for delivering treatment or ablation energy to tissue.
    Type: Application
    Filed: October 17, 2017
    Publication date: April 18, 2019
    Inventors: Gonzalo MARTINEZ, Timothy G. LASKE, Mark T. STEWART
  • Publication number: 20190030328
    Abstract: A method, system, and device for electroporation. A system may include a medical device with a plurality of electrodes borne on an expandable element and an energy generator in communication with the electrodes. The energy generator may have processing circuitry configured to selectively deliver electroporation energy to at least one of the electrodes. The processing circuitry may determine whether an alert condition is present and, if so, cease the delivery of electroporation energy to one or more electrodes identified as the cause of the alert condition and/or prevent the delivery of electroporation energy to the one or more electrodes identified as the cause of the alert condition. The energy generator may also be configured to deliver electroporation energy in a sequence of a plurality of energy delivery patterns to enhance lesion formation.
    Type: Application
    Filed: July 28, 2017
    Publication date: January 31, 2019
    Inventors: Mark T. STEWART, Brian T. HOWARD