Abstract: An endocardial lead for implantation in a right heart chamber for responding to blood pressure and temperature and providing modulated pressure and temperature related signals to an implanted or external hemodynamic monitor and/or cardiac pacemaker or pacemaker/cardioverter/defibrillator. The lead has a sensor module formed in its distal end and is coupled to a monitor that powers a sensor circuit in the sensor module. The sensor module is formed with a pickoff capacitor that changes capacitance with pressure changes and a reference capacitor that is relatively insensitive to pressure changes. The sensor circuit provides charge current that changes with temperature variation at the implant site, alternately charges and discharges the two capacitors, and provides timing pulses having distinguishable parameters at the end of each charge cycle that are transmitted to the demodulator.

Abstract: An implantable medical device has a novel ceramic enclosure with joinable multi-layered clamshells. In the preferred embodiment one half of the enclosure carries the hybrid circuitry and feedthroughs of, for example, a pacemaker, while, the other half carries a battery. The advantages over the prior art include higher transparency to radio frequency waves (for telemetry purposes), and reduced costs and construction time.