Abstract: A shield located within an implantable medical lead may be terminated in various ways at a metal connector. The shield may be terminated by various joints including butt, scarf, lap, or other joints between insulation layers surrounding the lead and an insulation extension. The shield may terminate with a physical and electrical connection to a single metal connector. The shield may terminate with a physical and electrical connection by passing between an overlapping pair of inner and outer metal connectors. The metal connectors may include features such as teeth or threads that penetrate the insulation layers of the lead. The shield may terminate with a physical and electrical connection by exiting a jacket of a lead adjacent to a metal connector and lapping onto the metal connector.

Abstract: A shield located within an implantable medical lead may be terminated in various ways. The shield may be terminated by butt, scarf, lap, or other joints between insulation layers surrounding the lead and an insulation extension. For lap joints, a portion of an outer insulation layer may be removed and a replacement outer insulation layer is positioned in place of the removed outer insulation layer, where the replacement layer extends beyond an inner insulation layer and the shield. The replacement layer may also lap onto a portion of the insulation extension. The barbs may be located between the replacement layer and the inner insulation layer or the insulation extension. The shield wires have ends at the termination point that may be folded over individually or may be capped with a ring located within one of the insulation layers of the jacket.

Abstract: Implantable medical systems include implantable medical leads that have magnetic orientation-independent magnetically actuated switches that are placed in the conduction path to the electrode of the lead. Thus, regardless of the orientation of a substantial magnetic field like that from an MRI machine to the lead and switch within the lead, the switch opens when in the presence of that substantial magnetic field. The switch may be placed in close proximity to the electrode such that the opening of the switch disconnects the electrode from the majority of the conduction path which thereby produces a high impedance for RF current and reduces the amount of heating that may occur at the electrode when in the presence of substantial levels of RF electromagnetic energy as may occur within an MRI machine.

Abstract: An implantable medical lead has a torsional stiffness and is rotationally coupled to a stylet. Applying rotation directly to the lead in turn causes rotation of the stylet. Where the stylet has a bent tip for purposes of steering the lead, the rotation applied to the lead rotates the bent tip so that the lead can be steered by rotating the lead rather than rotating a hub of the stylet. The rotational coupling may be achieved through one or more features provided for the lead and/or the stylet, such as a feature within a lumen of the lead that mates to a feature along the stylet or a feature of the stylet hub that engages the proximal end of the lead. The torsional stillness of the lead may be provided by adding a feature within the lead body, such as a braided metal wire or an overlapping foil.

Abstract: 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.