Implantable medical device lead incorporating insulated coils formed as inductive bandstop filters to reduce lead heating during mri

Abstract

To provide radio-frequency (RF) bandstop filtering within an implantable lead, such as a pacemaker lead, one or more segments of the tip and ring conductors of the lead are formed as insulated coils to function as inductive band stop filters. By forming segments of the conductors into insulated coils, a separate set of discrete or distributed inductors is not required, yet RF filtering is achieved to, e.g., reduce lead heating during magnetic resonance imaging (MRI) procedures. To enhance the degree of bandstop filtering at the RF signal frequencies of MRIs, additional capacitive elements are added. In one example, the ring electrode of the lead is configured to provide capacitive shunting to the tip conductor. In another example, a capacitive transition is provided between the outer insulated coil and proximal portions of the ring conductor. In still other examples, conducting polymers are provided to enhance capacitive shunting. The insulated coils may be spaced at ¼ wavelength locations.

Dependencies are inferred from the claim text.