Patent ID: 8306633
Filing Date: 2012-11-06
Classification: A61N,Y10T

Abstract:
1. A lead system comprising: an elongate lead body extending from a proximal end portion to a distal end portion; an active fixation mechanism movable longitudinally relative to the elongate lead body; a stationary electrode member at the distal end portion; a non-stationary electrode member at the distal end portion, the non-stationary electrode member movable longitudinally relative to the elongate lead body between a retracted position and an extended position; at least one annular electrical interconnect in the distal end portion including an outer diameter electrically connected to the stationary electrode member and an inner diameter electrically connected to the non-stationary electrode member, wherein the non-stationary electrode member moves relative to and remains in mechanical and electrical contact with the inner diameter of the at least one annular electrical interconnect when the non-stationary electrode member is moved longitudinally between the retracted position and the extended position; and a capacitor electrically connected to the non-stationary electrode member and stationary electrode member, wherein the capacitor is configured such that, at frequencies associated with magnetic resonance imaging (MRI), the capacitor operates as a short circuit between the non-stationary electrode member and stationary electrode member and, at frequencies associated with pacing and sensing, the capacitor operates as an open circuit between the non-stationary electrode member and stationary electrode member.