Abstract: Implantable medical leads include a shield that is guarded at a termination by having a first portion and a second portion of the shield, where the first portion is between a termination of the shield at the second portion and an inner insulation layer that surrounds the filars. The first portion may reduce the coupling of RF energy from the termination of the shield at the second portion to the filars. The first and second portions may be part of a continuous shield, where the first and second portions are separated by an inversion of the shield. The first and second portions may instead be separate pieces. The first portion may be noninverted and reside between the termination at the second portion and the inner layers, or the first portion may be inverted to create first and second sub-portions. The shield termination at the second portion is between the first and second sub-portions.

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. 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: 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.

Abstract: 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.

Abstract: 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.

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 method of manufacturing an implantable medical device having reduced MRI image distortion, includes producing an implantable medical device. The implantable medical device has a configuration that comprises a housing and one or more internal components disposed within the housing. The configuration is based upon a design process that includes creating a first prototype, determining the aggregate relative magnetic permeability of the first prototype, and modifying the design of the first prototype by at least one of (a) selecting and adding a diamagnetic shimming material to the first prototype or (b) repositioning one or more internal components of the first prototype. Modifying the design results in a modified design that is the configuration for the implantable medical device.

Abstract: 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.

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 method of manufacturing an implantable medical device having reduced MRI image distortion, includes producing an implantable medical device. The implantable medical device has a configuration that comprises a housing and one or more internal components disposed within the housing. The configuration is based upon a design process that includes creating a first prototype, determining the aggregate relative magnetic permeability of the first prototype, and modifying the design of the first prototype by at least one of (a) selecting and adding a diamagnetic shimming material to the first prototype or (b) repositioning one or more internal components of the first prototype. Modifying the design results in a modified design that is the configuration for the implantable medical device.

Abstract: Implantable medical leads include a shield that is guarded at a termination by having a first portion and a second portion of the shield, where the first portion is between a termination of the shield at the second portion and an inner insulation layer that surrounds the filars. The first portion may reduce the coupling of RF energy from the termination of the shield at the second portion to the filars. The first and second portions may be part of a continuous shield, where the first and second portions are separated by an inversion of the shield. The first and second portions may instead be separate pieces. The first portion may be noninverted and reside between the termination at the second portion and the inner layers, or the first portion may be inverted to create first and second sub-portions. The shield termination at the second portion is between the first and second sub-portions.

Abstract: Implantable medical leads include a shield that is guarded at a termination by having a first portion and a second portion of the shield, where the first portion is between a termination of the shield at the second portion and an inner insulation layer that surrounds the filars. The first portion may reduce the coupling of RF energy from the termination of the shield at the second portion to the filars. The first and second portions may be part of a continuous shield, where the first and second portions are separated by an inversion of the shield. The first and second portions may instead be separate pieces. The first portion may be noninverted and reside between the termination at the second portion and the inner layers, or the first portion may be inverted to create first and second sub-portions. The shield termination at the second portion is between the first and second sub-portions.

Abstract: Implantable medical leads include a shield that is guarded at a termination by having a first portion and second portion of the shield, where the first portion is between a termination of the shield at the second portion and an inner insulation layer surrounding the filars. The first portion may reduce the coupling of RF energy from the termination of the shield at the second portion to the filars. The first and second portions may be part of a continuous shield, where the first and second portions are separated by an inversion of the shield. The first and second portions may instead be separate pieces. The first portion may be noninverted residing between the termination at the second portion and inner layers, or the first portion may be inverted to create first and second sub-portions. The shield termination at the second portion is between the first and second sub-portions.

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.

Abstract: Grounding of a shield that is located in an implantable medical lead may be done in many ways. The ground pathway may couple to the shield at a point that is outside of a header of an implantable medical device to which the implantable medical lead is attached. The ground pathway may couple to the shield at a point that is within the header of the implantable medical device. The ground pathway may terminate at the metal can of the implantable medical device. As another option, the ground pathway may terminate at a ground plate that is mounted to the header. The ground pathway may be direct current coupled from the shield to the can or ground plate. Alternatively, the ground pathway may include one or more capacitive couplings that provide a pathway for induced radio frequency current.

Abstract: A method of manufacturing an implantable medical device having reduced MRI image distortion, includes producing an implantable medical device. The implantable medical device has a configuration that comprises a housing and one or more internal components disposed within the housing. The configuration is based upon a design process that includes creating a first prototype, determining the aggregate relative magnetic permeability of the first prototype, and modifying the design of the first prototype by at least one of (a) selecting and adding a diamagnetic shimming material to the first prototype or (b) repositioning one or more internal components of the first prototype. Modifying the design results in a modified design that is the configuration for the implantable medical device.

Abstract: 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.

Abstract: An implantable medical device includes a housing formed of a first material and a first electronic component provided within the housing. The implantable medical device also includes a second material provided in contact with at least a portion of the housing. At least one of the housing and the first electronic component has a magnetic permeability in a magnetic field that differs from the magnetic permeability of water. The second material is provided in an amount effective to reduce MRI image distortion caused by the implantable medical device.

Abstract: Implantable medical leads include a shield that is guarded at a termination by having a first portion and a second portion of the shield, where the first portion is between a termination of the shield at the second portion and an inner insulation layer that surrounds the filars. The first portion may reduce the coupling of RF energy from the termination of the shield at the second portion to the filars. The first and second portions may be part of a continuous shield, where the first and second portions are separated by an inversion of the shield. The first and second portions may instead be separate pieces. The first portion may be noninverted and reside between the termination at the second portion and the inner layers, or the first portion may be inverted to create first and second sub-portions. The shield termination at the second portion is between the first and second sub-portions.

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.