Medtronic, Inc.

Bryan D Stem

Spencer M Bondhus

James M Olsen

Mark J Conroy

Richard T Stone

Jamu Alford

Brian T Stolz

John D Welter

Spencer Fodness Bondhus

Michael Kalm

Spencer Fodness-Bondhus

A temperature sensor is included within a lead in proximity to distal electrodes. The temperature sensor measures temperature change at the electrode to tissue interface. Actions can be taken when the temperature exceeds a threshold due to heating from current induced by radio frequency energy from an MRI scan. The actions may include sending a signal via telemetry from the implanted device to an external device to produce an alarm to alert an MRI technician or to instruct the MRI scanner to alter the MRI scan. The actions may include activating a switch in the conduction path of an implanted lead to block some of the RF energy and/or to activate a shunt in the conduction path to divert some of the RF energy. The temperature sensor may be of various forms and may be mounted in various locations within the lead.

Methods, implantable medical leads, and related systems to monitor and limit temperature changes in proximty to electrodes

Conductors within an implantable medical lead that carry stimulation signal signals are at least partially embedded within a lead body of the medical lead over at least a portion of the length of the conductors while being surrounded by a radio frequency (RF) shield. A space between the shield and the conductors is filled by the presence of the lead body material such that body fluids that infiltrate the lead over time cannot pool in the space between the shield and the conductors. The dielectric properties of the lead body are retained and the capacitive coupling between the shield and the conductors continues to be inhibited such that current induced on the shield is inhibited from being channeled onto the conductors. Heating at the electrodes of the medical lead is prevented from becoming excessive.

Devices, systems and methods to reduce coupling of a conductor within an implantable medical lead

A shield layer is added to an existing lead or lead extension by applying the shield layer to the lead body between the proximal contact and distal electrode of the lead body. The shield layer may be covered with an outer insulative layer. An inner insulative layer may be applied over the lead body prior to adding the shield layer and the outer insulative layer. The shield layer may have a terminator applied to the end of the shield layer to prevent migration of the shield layer through the outer insulative layer. The shield layer may be of various forms including a tubular braided wire structure or a tubular foil. The tubular braided wire structure may be applied to the lead body by utilizing the lead body as a mandrel within a braiding machine.

Methods of shielding implantable medical leads and implantable medical lead extensions

Medical lead bodies that are paired each include a braided conductive shield. The braided conductive shield of one lead body has a value for a physical parameter that differs from a value for the physical parameter of the second lead body. The difference in values of the physical parameter for the paired lead bodies results in a reduction in heating from exposure of the lead bodies to radiofrequency energy at electrodes associated with the lead bodies. The lead bodies may be paired by being implanted adjacently to one another. The lead bodies may be further paired by being coupled to a same distal body, such as a paddle containing the electrodes.

Paired medical lead bodies with conductive shields providing destructive interference

Devices, systems and methods to reduce coupling of a shield and a conductor within an implantable medical lead

Paired medical lead bodies with braided conductive shields having different physical parameter values

The function of a strain relief loop of an implantable medical lead is preserved by inhibiting restriction of the strain relief loop from tissue growth onto the strain relief loop. The restriction may be inhibited by either obstructing tissue growth and/or by utilizing a mechanical advantage to overcome the restriction. The tissue growth may be obstructed be isolating the interior of the strain relief loop such as by enclosing the strain relief loop or including an object within the loop. The mechanical advantage to overcome restriction from tissue growth may be provided in various ways such as utilizing a spring loaded mechanism or a structure such as an elastic mesh, tube, or mold having an inherent bias toward a steady state position.

Methods and devices for ihibiting tissue growth from restricting a strain relief loop of an implantable medical lead

Strain relief loop holders maintain the strain relief loop formed in a lead while also addressing the excessive heating at the point in the loop where the medical lead intersects with itself. The strain relief loop includes a body section that the medical lead passes through where the intersection occurs. The body section may be a thermal non-conductor and isolate from excessive heating at the intersection point or may be a thermal conductor and distribute the excessive heating. The strain relief loop may include features such as arms or a coil extending from the body segment with arm segments at the ends of the arms defining lead passageways that assist in maintaining the strain relief loop. The body segment may have a single lead passageway where the intersection point occurs or may have multiple lead passageways. The body itself may house the loop by forming a loop or a capsule.

Strain relief loop holders for medical leads and systems

Methods and devices for inhibiting tissue growth from restricting a strain relief loop of an implantable medical lead

Strain relief loop holders maintaining strain relief loop formed in a lead while also addressing excessive heating at the point in the loop where the medical lead intersects itself. The strain relief loop includes a body section that the medical lead passes through where the intersection occurs. The body section may be a thermal non-conductor and isolate from excessive heating at the intersection point or may be a thermal conductor and distribute the excessive heating. The strain relief loop may include features such as arms or a coil extending from the body segment with arm segments at the ends of the arms defining lead passageways that assist in maintaining the strain relief loop. The body segment may have a single lead passageway where the intersection point occurs or may have multiple lead passageways. The body itself may house the loop by forming a loop or a capsule.

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Minneapolis, MN, United States of America

Bryan D Stem