Patent ID: 8032228

Claim:
A medical device, comprising: a pulse generator; a lead including an electrode configured to contact body tissue in a body vessel and a lead conductor connecting the pulse generator with the electrode via first and second conductive paths, the first conductive path parallel to the second conductive path; a first switch electrically coupled in series between the lead conductor and the electrode, the first switch including a non-conductive state, the non-conductive state preventing formation of the first conductive path between the pulse generator and the electrode in the presence of an MRI magnetic field, the first switch including a conductive state in the absence of the magnetic field, the conductive state allowing formation of the conductive path between the pulse generator and the electrode; and a second switch electrically connected in series between the lead conductor and the electrode, the second switch including a non-conductive state preventing formation of the second conductive path between the pulse generator and the electrode, the second switch including a conductive state allowing formation of the second conductive path between the pulse generator and the electrode when a voltage applied across the second switch exceeds a threshold voltage; wherein the first switch in the non-conductive state and the second switch in the non-conductive state electrically shields the electrode from at least electromagnetic radiation and induced voltages in the presence of the MRI magnetic field.