Leads with high surface resistance
AssigneeCardiac Pacemakers, Inc.
InventorsYingbo Li, Masoud Ameri
Life of this patent
Estimating the term…
Abstract
Implantable medical leads having resistance characteristics adapted to dissipate radio frequency (RF) electromagnetic energy during medical procedures such as magnetic resonance imaging (MRI) are disclosed. An illustrative medical device includes a lead having an inner electrical conductor operatively coupled to an electrode and a pulse generator, and one or more outer resistive shields that radially surround the inner conductor and dissipate RF energy into the surrounding body tissue along the length of the lead.
Claims12
An implantable medical device for use in a magnetic resonance imaging environment, the medical device comprising:
- a lead including an inner electrical conductor operatively coupled to an electrode, and a plurality of outer resistive shields each comprising a helically-shaped coil radially disposed about the inner electrical conductor along at least a portion of a length of the lead, the helically-shaped resistive shield coils spaced apart and electrically isolated from each other via a non-conductive gap;
- the inner electrical conductor having a first resistance;
- the helically-shaped coils each having a second resistance greater than the first resistance;
- and
- wherein the helically-shaped coils are configured to dissipate RF electromagnetic energy received by an MRI device along the length of the lead.
An implantable medical device for use in a magnetic resonance imaging environment, the medical device comprising:
- a lead including a helically-shaped electrical conductor coil operatively coupled to an electrode, and a plurality of resistive shields each radially surrounding a portion of the conductor coil along a length of the lead;
- the conductor coil including an electrically conductive material and having a first resistance;
- each of the outer resistive shields spaced apart and electrically isolated from each other and the conductor coil along the length of the lead, the outer resistive shields each having a second resistance greater than the first resistance of the conductor coil;
- and
- wherein the at least one outer resistive shield is configured to dissipate RF electromagnetic energy received by an MRI device along the length of the lead.
An implantable medical device for use in a magnetic resonance imaging environment, the medical device comprising:
- a lead including an electrical conductor wire operatively coupled to an electrode, the conductor wire having a resistivity that continuously varies across a width of the lead between a center portion of the conductor wire and an outer portion of the conductor wire;
- the conductor wire includes an inner conductor core and a plurality of outer resistive shields radially disposed about the inner conductor core, and wherein the resistivity of each of the outer resistive shields successively increases towards the outer portion of the conductor wire;
- the center portion of the conductor wire having a first resistivity;
- the outer portion of the conductor wire having a second resistivity greater than the first resistivity;
- and
- wherein the outer portion of the conductor wire is configured to dissipate RF electromagnetic energy received by an MRI device along a length of the lead.
Dependencies are inferred from the claim text.