Implantable medical device lead incorporating a conductive sheath surrounding insulated coils to reduce lead heating during mri

Abstract

A conducting sheath is provided along at least a portion of an implantable medical device lead, and preferably along substantially its entire length, for mitigating heating problems arising during magnetic resonance imaging (MRI) procedures, particularly problems arising due to a problem described herein as the “coiling effect.” During device implant, the clinician may elect to wrap or coil excess proximal portions of leads around or under the medical device being implanted. Thereafter, during MRI procedures, shunt capacitance may develop between the housing of the implantable device and insulated coils within the proximal portions of the lead that are near the device, resulting in greater lead heating during the MRI. The conducting sheath helps suppress induced currents and also reduces or eliminates shunt capacitance. The conducting sheath may be, for example, formed using a metal mesh or a conducting polymer tube incorporating non-ferrous metal powders. The sheath may be formed in ¼ wavelength segments.

Dependencies are inferred from the claim text.