Abstract: A medical device lead includes an insulative lead body, outer and inner conductive coils, and a flexible core assembly. The outer conductive coil extends through the lead body and is coupled to a first electrode at a distal end of the outer conductive coil. The inner conductive coil extends coaxially with the outer conductive coil, is coupled to a second electrode at a distal end of the inner conductive coil, and includes a central lumen. The flexible core assembly is disposed in the central lumen and is comprised of a material that has a saturation magnetization of at least about 1.5 T and a relative permeability of greater than one. The flexible core assembly includes a positioning interface configured for manipulation of the flexible core assembly such that the flexible core assembly translates through the central lumen during insertion and extraction of the flexible core assembly.

Abstract: An implantable medical lead exhibits reduced heating under MRI conditions. The lead includes a multi-layer coil conductor including an inner coil layer, a middle coil layer disposed around the inner coil layer, and an outer coil layer disposed around the middle coil layer. Each of the coil layers is characterized by one or more of a filar thickness, a coil pitch, or a coil diameter configured such that the coil conductor exhibits a high inductance when exposed to MRI radiation. Each of the coil layers is electrically connected to the other coil layers to provide parallel conductive paths resulting in a coil conductor resistance suitable for defibrillation lead applications.

Abstract: An implantable electrical lead having a flexible body and including a multi-layer coil conductor extending within the longitudinal body lumen from the connector assembly to at least the electrode, the multi-layer coil conductor including a first coil layer a second coil layer disposed about the first coil layer, wherein at least one parameter of the first and the second coil layer is configured such that the lead exhibits a predetermined axial stiffness or bending stiffness.

Abstract: An implantable lead may have a distal assembly including a coupler and a fixation helix secured to the coupler. The fixation helix may be formed of a filar having a non-circular cross-sectional profile having a major dimension and a minor dimension. The major dimension may be disposed transversely to a longitudinal axis of the helical electrode.

Abstract: The present invention provides medical devices that contain polyisobutylene urethane copolymers, polyisobutylene urea copolymers and polyisobutylene urethane/urea copolymers. More particularly, the present invention provides medical leads that contain such copolymers.

Abstract: Implantable medical leads and methods of forming such leads are disclosed. An implantable medical lead includes a lead body, a swage base coupled to the lead body, and a polymeric member interposed at least in part between the swage base and at least one rigid component of the lead such as an electrode or annular ring. The swage base includes an annular-shaped body including a flange having a number of protrusions that extend radially outward from the flange. During a swaging process, the protrusions on the flange are compressed against the polymeric member, forming a number of channels in the member that mechanically bond the member to the swage base.

Abstract: An implantable lead may include a housing and a laminate distal seal disposed across a distal end of the housing. A coupler and a fixation helix secured to the coupler may be disposed within the housing. The fixation helix may have a retracted position in which the fixation helix does not penetrate the laminate distal seal and an extended position in which the fixation helix has pierced the laminate distal seal and extends therethrough.

Abstract: A conductor assembly for a medical device lead includes a helically coiled conductor including a plurality of turns having a coil pitch and an outer diameter and consisting of one filar having a filar diameter. The coil pitch and outer diameter are selected based on the filar diameter to minimize heating of the helically coiled conductor in the presence of an MRI field. A polymer sheath is formed about the helically coiled conductor such that the coil pitch of the unifilar helically coiled conductor is maintained. The polymer sheath is configured to increase a torque transmitting capacity of the helically coiled conductor.

Abstract: An implantable lead may have a distal assembly including a coupler, a fixation helix secured to the coupler and a housing in which the fixation helix and the coupler are disposed. The distal assembly may include an annular seal that is disposed between the coupler and the housing and that provides an at least substantially fluid-tight seal between the coupler and the housing.

Abstract: An implantable lead may have a distal assembly including a coupler and a fixation helix secured to the coupler. The coupler may include a helical groove that is configured to accommodate the fixation helix. The helical groove may facilitate attaching the fixation helix to the coupler by threading the fixation helix into the helical groove. A weld may provide a secondary attachment between the fixation helix and the coupler.

Abstract: An apparatus for applying a signal to a nerve for the treatment of a disorder includes a main electrode body of biocompatible dielectric material and having a concave upper surface and an opposite lower surface. The concave upper surface curves about an axis and has a curvature sized to receive a nerve within the concave surface with an axis of the nerve substantially parallel to an axis of the concave surface. An electrode contact of electrically conductive material is secured to the main electrode body and has an electrode contact surface exposed on the concave surface. The concave surface terminates at opposite first and second upper ends. The electrode contact has a first end near the first end of the concave surface. A secondary electrode body of biocompatible dielectric material is attached to the first upper end of the concave surface.

Abstract: The lead includes a helical fixation member coupled to the distal end of the lead body. The helical fixation member has at least one internal reservoir and a plurality of elution ports in fluid communication with the internal reservoir. A therapeutic agent composition is disposed within the internal reservoir. Additionally, the helical fixation member includes a sealed distal end to prevent coring of the cardiac tissue.

Abstract: Medical electrical leads equipped with spacer elements and configured for use during medical procedures such as magnetic resonance imaging (MRI) are disclosed. An illustrative medical electrical lead includes a proximal connector, an insulated lead body including at least one electrode, a helically coiled conductor wire, and a helically coiled spacer element interstitially disposed between adjacent turns of the conductor wire.

Abstract: Implantable medical leads with magnetic shielding and methods of shielding implantable leads from magnetic fields during medical procedures such as magnetic resonance imaging (MRI) are disclosed. An exemplary implantable medical lead includes a helically coiled inner electrode conductor wire, a helically coiled outer electrode conductor wire disposed radially about the inner electrode conductor wire, and at least one layer of insulation that electrically isolates the inner and outer electrode conductor wires. The inner electrode conductor wire can have a hollowed, multifilar configuration including six or more co-radially wound wire filars. The outer electrode conductor wire is electrically isolated from the inner electrode conductor wire, and may have either a single or double filar configuration.

Abstract: A cardiac rhythm management device that includes a lead and a pulse generator. The lead can comprise a lead body, a helical composite electrode, a composite conductor and a proximal connector. The helical composite electrode can have first and second electrodes in a co-axial configuration. The composite connector can electrically connect the first and second electrodes to the proximal connector. The proximal connector can be configured to couple to the pulse generator.

Abstract: Medical device leads with magnetic shielding and methods of shielding medical device leads from magnetic fields during medical procedures such as magnetic resonance imaging (MRI) are described. An illustrative implantable medical device includes a lead including a lead conductor having a length and a helically coiled ribbon shield radially surrounding the lead conductor along at least a portion of the length of the lead. The ribbon shield can include one or more inner ribbon conductors and/or one or more outer ribbon conductors. The outer ribbon conductor can have a variable width (e.g., a necked-down configuration, an arrowhead configuration, or an undulating configuration) along the length of the lead. In some cases, the helically coiled ribbon has a variable pitch along the length of the lead that may be the same as or different from that of the lead conductor pitch.

Abstract: A cardiac rhythm management device that can comprise a lead and a pulse generator. The lead can comprise lead body, a composite conductor, a stylet guide, two or more electrodes and a proximal connector. The composite conductor can comprise two or more conductors which can electrically couple the electrodes to the proximal connector. The electrodes can be disposed on a distal portion of the lead body and can be longitudinally spaced from one another. The proximal connector can be configured to couple to the pulse generator.

Abstract: An implantable endocardial lead with retractable sharpened helix. The piston has a central bore for receiving a specialized stylet. The stylet comprises a flexible wire having an enlarged distal end or tip. An elastomeric sliding sleeve fits over the wire. When the proximal end of the stylet is inserted into the bore in the piston, the wire can be withdrawn slightly, pulling the enlarged tip into the tube, and wedging the tube against the walls of the bore. By manipulating the stylet, the helix can be exposed outside of the lead, or retractable into the lead, as desired.