Abstract: The present disclosure provides one or more structures, techniques, components and/or methods for avoiding or positively resolving failure modes for an implanted medical device coupled to one or more sensors. A common fault scenario involves unintended stimulation during therapy delivery. A pacing stimulus can couple to exposed conductive portion(s) of a medical electrical lead (e.g., a tip portion) that includes a sensor to cause the stimulation. Stimulation also occurs due to insulation breaches of a lead. Stimulation can also result from a breach in insulation surrounding a conductive set screw that couples the lead to active circuitry. Stimulation also results when high energy therapy energy shunts to sensor circuitry (e.g., sensor bus) via insulation breach of the sensor lead and/or the circuitry.

Abstract: One aspect of the invention involves a possible fault scenario due to a breach of an inner layer of insulation of an elongated medical electrical lead which couples an active electrical circuit for an active implantable medical device (AIMD)—typically within a conductive AIMD housing—to a sensor disposed within a sensor capsule. In one form, the AIMD provides physiological sensing of a patient parameter, such as endocardial pressure via a chronically implanted absolute pressure sensor. In such a physiological monitor, a high impedance connection is established between the active electrical circuit and the conductive AIMD housing. In a therapy delivering AIMD, a high impedance connection is established between therapy electrodes and the active electrical circuit. As a result, any errant electrical current(s) will be shunted directly to the reference-ground of the sensor-bearing lead in lieu of traveling through a patient's tissue or conductive body fluid.