Radiopaque markers represent that a lead is suitable for a particular medical procedure such as a magnetic resonance image scan and are added to the lead or related device. The markers may be added after implantation of the lead in various ways including suturing, gluing, crimping, or clamping a radiopaque tag to the lead or to the device. The markers may be added by placing a radiopaque coil about the lead, and the radiopaque coil may radially contract against the lead to obtain a fixed position. The markers may be added by placing a polymer structure onto the lead where the polymer structure includes a radiopaque marker within it. The polymer structure may include a cylindrical aperture that contracts against the lead to fix the position of the polymer structure. The polymer structure may form a lead anchor that includes suture wings that can be sutured to the lead.

A corona comprises a central electrode surrounded by an insulator, which is surrounded by a conductive component. The conductive component includes a shell and an intermediate part both formed of an electrically conductive material. The intermediate part is a layer of metal which brazes the insulator to the shell. An outer surface of the insulator presents a lower ledge, and the layer of metal can be applied to the insulator above the lower ledge prior to or after inserting the insulator into the shell. The conductive inner diameter is less than an insulator outer diameter directly below the lower ledge such the insulator thickness increases toward the electrode firing end. The insulator outer diameter is also typically less than the shell inner diameter so that the corona igniter can be forward-assembled.

A reversed-assembled corona igniter including an insulator, central electrode, and metal shell, wherein an outer diameter of the insulator increases adjacent a lower end of the metal shell to achieve an electrical advantage is provided. In addition, the insulator maintains strength because is not placed under tension during or after assembly, or once disposed in an engine. To achieve the increase in insulator outer diameter, the insulator includes a lower shoulder adjacent the shell firing end. An intermediate part, such as braze and/or a metal ring, is disposed between the insulator outer surface and the shell adjacent the shell firing end. To prevent tension in the insulator, the insulator can be supported at only one location between the insulator upper end and the insulator lower end, for example along the intermediate part.

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 stiffness of the lead may be provided by adding a feature within the lead body, such as a braided metal wire or an overlapping foil.

A cable includes a flexible jacket extending along a length and first and second lateral axes perpendicular to the length. The jacket also defines flat major surfaces that are parallel to each other and spaced apart on opposite sides of the first lateral axis. First and second inner wire assemblies extend within the jacket. The jacket maintains the first and second inner wire assembles in predetermined positions along the first lateral axis within 0.05 mm of each other and disposed on opposing sides of the second lateral axis. First and second outer wire assemblies also extend within the jacket. The outer wire assemblies include a wire of conductive filaments and an insulating layer of an enamel material surrounding the wire. The jacket maintains the first and second outer wire assemblies in positions along the first lateral axis and spaced apart from the first and second inner wire assemblies.

Implantable medical leads and implantable lead extensions include a shield. The implantable medical lead is coupled to the implantable lead extension. Stimulation electrodes of the implantable medical lead contact stimulation connectors within a housing of the implantable extension to establish a conductive pathway for stimulation signals from filars of the implantable extension to filars of the implantable medical lead. Continuity is established between the shield of the implantable medical lead and the implantable extension by providing a radio frequency conductive pathway within the housing. The radio frequency conductive pathway extends from a shield of the implantable extension to a shield connector that contacts a shield electrode of the implantable medical lead. The radio frequency conductive pathway may have various forms such as a jumper wire or an extension of the shield within the implantable extension.

A corona igniter (20) comprises a central electrode (22) surrounded by an insulator (26), which is surrounded by a conductive component. The conductive component includes a shell (34) and an intermediate part (36) both formed of an electrically conductive material. An outer surface (50) of the insulator (26) presents a lower ledge (52), and the intermediate part (36) is typically attached to the insulator (26) above the lower ledge (52) prior to inserting the insulator (26) into the shell (34). The conductive inner diameter (D.sub.g) is less than an insulator outer diameter (D.sub.io) directly below the lower ledge (52) such the insulator thickness (t.sub.i) increases toward the electrode firing end (40). The corona igniter (20) can be reversed-assembled by inserting an upper end (42) of the insulator into a firing end (56) of the shell.

Radiopaque markers represent that a lead is suitable for a particular medical procedure such as a magnetic resonance image scan and are added to the lead or related device. The markers may be added after implantation of the lead in various ways including suturing, gluing, crimping, or clamping a radiopaque tag to the lead or to the device. The markers may be added by placing a radiopaque coil about the lead, and the radiopaque coil may radially contract against the lead to obtain a fixed position. The markers may be added by placing a polymer structure onto the lead where the polymer structure includes a radiopaque marker within it. The polymer structure may include a cylindrical aperture that contracts against the lead to fix the position of the structure. The polymer structure may form a lead anchor that includes suture wings that can be sutured to the lead.

There is provided an acoustic element for placement in a sound path of a loudspeaker device, the acoustic element comprising a container and an acoustic volume increasing material located in the container. In an embodiment, the container comprises wall portions with different physical characteristics. In other embodiments, the walls of the container are made of the same material.

A method of forming an insulated conductor, includes forming an insulated conductor to modify a cross sectional shape thereof. Heating at least a portion of the insulated conductor to a selected temperature range. Maintaining the selected temperature range for at least a selected period of time thereby annealing the conductor. Forming the insulated conductor into a plurality of gable shaped loops; and maintaining insulating properties of an insulation layer of the insulated conductor. Also included is a method of annealing an insulated conductor.