| abstract |
Implantable medical leads are shielded with a braided shield that surrounds an inner layer of insulation. An outer layer of insulation may also surround the shield. The shield is designed with parameters that limit the passage of radio frequency energy, particularly in the magnetic resonance imaging spectrum, to filars that are surrounded by the inner layer of insulation. The braided shield has a plurality of parameters and corresponding ranges. The parameters include one or more of braid angle, wire size, number of wires wound per direction, number of wires in a bundle, wire spacing in an axial dimension, ultimate tensile strength, cross-sectional wire shape, material, and distance from termination to a nearest electrode. Additional parameters of the lead related to the shielding also include one or more of inner insulation thickness, and outer insulation thickness. |