Abstract: An apparatus and methods of rendering an active implantable medical device (AIMD) fault tolerant when such an AIMD couples to a chronically implantable physiologic sensor (IPS) adapted to be operatively deployed into contact with body fluid and/or tissue. An exemplary AIMD for implementing the teaching of this disclosure includes implantable cardioverter-defibrillator (ICDs) incorporating implantable pulse generator (IPG) circuitry and/or therapeutic substance delivery devices. Certain aspects involve sensors such as blood-based sensors (e.g., a saturated oxygen sensor, a pH sensor, a potassium-ion sensor, a calcium-ion sensor, a lactate sensor, a metabolite sensor, a glucose sensor). Various mechanical sensors can be used according to the disclosure and in some forms, more than one sensor couples to an AIMD.

Abstract: This disclosure relates to fault tolerant instantiations of a cardiac therapy delivery device such as an implantable cardiac stimulator (e.g., an implantable pulse generator, IPG, and/or an implantable cardioverter-defibrillator, ICD) coupled to an implantable physiologic sensor (IPS). According to the disclosure delivery of cardiac pacing and/or cardioversion-defibrillator therapy delivery can cause errors in output signals from an IPS. Resolution of such errors involves selectively energizing (or disconnecting the output signal from) the IPS during pacing and/or defibrillation therapy delivery. Programmable signal “blanking” in lieu of or in addition to the foregoing also improves the integrity of the output signal (i.e., continuously energize the IPS and ignore parts of the output signal). An ICD having a transient weakness in an insulated conductor used for the IPS signal can likewise have the IPS de-energized and/or blank the IPS output signal during high voltage therapy delivery.

Abstract: According to the invention, a possible fault scenario involves an insulation breach of a medical lead which couples signals and/or electrical energy between a sensor and a circuit-bearing, active implantable medical device (AIMD). An initial response involves disconnecting the power source from the sensor with subsequent responses including selective reconnection of the power source. If the fault spontaneously resolves, then power to the sensor can be restored and physiologic signals transmitted to operative circuitry of the AIMD. In addition, however, an intermediate mode is enabled with the power source only coupled temporarily, for example, during intervals when stimulation and/or capture of excitable tissue (e.g., myocardial tissue) is not likely to occur due to any electrical shunt current(s). Thus, applying energy to a sensor(s) during the refractory period of a cardiac chamber eliminates undesired tissue activation.

Abstract: An implantable cell/tissue-based biosensor device detects and/or monitors the amount of one or more specific analytes within a patient. Stimulation circuitry stimulates the cells/tissue of the biosensor device causing the cells/tissue to evoke a response that is altered by the presence of a specific analyte. Sensing circuitry detects the evoked response and the amount of analyte is determined based on the detected response.

Abstract: An implantable medical lead includes a device, such as a physiological sensor, that is coupled to one or more stimulation/sensing sensing conductors within the lead. When the implantable medical lead is coupled to an implantable medical device, the device carried by the lead both receives power from, and communicates with the implantable medical device via the one or more stimulation/sensing sensing conductors. Each of the one or more stimulation/sensing sensing conductors is also coupled to an electrode that is exposed to body tissue.

Abstract: An implantable medical lead includes a sensor capsule coupled to a lead body through which a sensor bus extends to couple with the sensor capsule. The sensor bus includes an elongate coil conductor, an elongate cable conductor extending within the coil conductor, and a material, positioned between the cable conductor and the coil conductor, which has a relative dielectric coefficient less than approximately 10.