Abstract: Techniques are provided for equipping sensing/pacing leads with physiological sensors without requiring additional conductors within the leads. In a bipolar lead example for use with a pacemaker, a sensor is connected between tip and ring conductors of the lead. The sensor is configured to be activated only in response to enhanced pacing pulse (EPPs) having magnitudes or durations greater than typical pacing pulses or in response to impedance detection pulses (IMPs). In a unipolar example, the sensor is connected to the tip conductor and includes an output terminal on the external housing of the lead for providing a return current path to the pacemaker. The sensor of the unipolar lead is likewise configured to respond only to EPPs or IMPs. In other examples, the sensors are configured to be fitted to the external housing of the lead and to derive power from the lead via electromagnetic induction. Still other examples include actuators rather than sensors.

Abstract: An implantable medical device in the form of a cardiac stimulation device such as a pacemaker or defibrillator includes a hermetically sealed housing having an inner peripheral surface, an electronic component such as an integrated electrical circuit sensitive to bombardment by alpha particles and located within the housing spaced from the inner peripheral surface, and blocking material intermediate the inner peripheral surface of the housing and the electronic component capable of suppressing alpha particles having an energy level up to about 15 mev directed towards the electronic component. The blocking material has a thickness of at least 0.010 inches; it may be sheet material; it may be congruently attached to the inner peripheral surface of the housing; or it may be a liquid coating applied to the inner peripheral surface and subsequently cured.

Abstract: A method and assembly for selectively actuating features of implanted medical devices with a magneto-static field. The method includes selectively exposing the implanted device to a static magnetic field source, selectively shielding the magnetic field source, and distancing the shielded magnetic field source from the medical device. One version of the assembly includes a permanent magnet and a displaceable shield assembly that shields the magnetic field generated by the magnet in one configuration and is displaceable to a second configuration wherein the magnetic field is at least partially exposed. In another version, the assembly is an electromagnet that can be selectively activated and deactivated. The electromagnet generates minimal magnet field when it is off.

Abstract: A method and assembly for selectively actuating features of implanted medical devices with a magneto-static field. The method includes selectively exposing the implanted device to a static magnetic field source, selectively shielding the magnetic field source, and distancing the shielded magnetic field source from the medical device. One version of the assembly includes a permanent magnet and a displaceable shield assembly that shields the magnetic field generated by the magnet in one configuration and is displaceable to a second configuration wherein the magnetic field is at least partially exposed. In another version, the assembly is an electromagnet that can be selectively activated and deactivated. The electromagnet generates minimal magnet field when it is off.