Abstract: An implantable medical device (IMD) may include a plurality of coils that may be used to recharge a power supply of the IMD and/or provide telemetry for the IMD. The IMD may be configured to couple all of the coils in series, such that currents that are induced by each of the coils are added together when the IMD is exposed to an electromagnetic field. The IMD may be configured to alter the coupling of the coils such that the coils are coupled in series opposition, such that currents that are induced by some coils of the IMD are opposed by currents that are induced by other coils of the IMD.

Abstract: An implantable medical device (IMD) may include a plurality of coils that may be used to recharge a power supply of the IMD and/or provide telemetry for the IMD. The IMD may be configured to couple all of the coils in series, such that currents that are induced by each of the coils are added together when the IMD is exposed to an electromagnetic field. The IMD may be configured to alter the coupling of the coils such that the coils are coupled in series opposition, such that currents that are induced by some coils of the IMD are opposed by currents that are induced by other coils of the IMD.

Abstract: An implantable medical device (IMD) may include a plurality of coils that may be used to recharge a power supply of the IMD and/or provide telemetry for the IMD. The IMD may be configured to couple all of the coils in series, such that currents that are induced by each of the coils are added together when the IMD is exposed to an electromagnetic field. The IMD may be configured to alter the coupling of the coils such that the coils are coupled in series opposition, such that currents that are induced by some coils of the IMD are opposed by currents that are induced by other coils of the IMD.

Abstract: An implantable medical device (IMD) may include a plurality of coils that may be used to recharge a power supply of the IMD and/or provide telemetry for the IMD. The IMD may be configured to couple all of the coils in series, such that currents that are induced by each of the coils are added together when the IMD is exposed to an electromagnetic field. The IMD may be configured to alter the coupling of the coils such that the coils are coupled in series opposition, such that currents that are induced by some coils of the IMD are opposed by currents that are induced by other coils of the IMD.

Abstract: This disclosure describes techniques for reducing, and possibly eliminating, adverse effects caused by signals induced on an inductive antenna of an implanted medical device by varying magnetic fields from a source of interference, such as the gradient magnetic fields applied during an MRI procedure. For example, the implantable medical device includes an inductive antenna that receives signals via inductive coupling, a filter circuit that attenuates signals induced on the inductive antenna by varying magnetic fields generated from a source of interference and substantially passes signals induced on the inductive antenna by varying magnetic fields generated by an expected source and a telemetry module that processes the signals from the filter circuit.

Abstract: This disclosure describes techniques for reducing, and possibly eliminating, adverse effects caused by signals induced on an inductive antenna of an implanted medical device by varying magnetic fields from a source of interference, such as the gradient magnetic fields applied during an MRI procedure. For example, the implantable medical device includes an inductive antenna that receives signals via inductive coupling, a filter circuit that attenuates signals induced on the inductive antenna by varying magnetic fields generated from a source of interference and substantially passes signals induced on the inductive antenna by varying magnetic fields generated by an expected source and a telemetry module that processes the signals from the filter circuit.

Abstract: A system and method for acquiring and processing an EGM signal during a pacing event, wherein a unique converter code is generated upon digitizing of the EGM signal and encrypted in the EGM signal to demarcate a transient event. The system further provides dynamic filtering of the EGM signal and subsequent detection of an intrinsic event signal during the pacing event, from which rhythm events may be diagnosed and classified.

Abstract: In general, the invention is directed to techniques for electrically detecting physiological events. The physiological events may include cardiac events such as R waves or p waves. In addition, the physiological events may include respiratory events. In general, the techniques involve converting an analog physiological signal to a digital delta value, correlating the digital delta value with a correlation template, and detecting a physiological event based on an output of the correlation. A digital correlation-based technique, as described herein, is implemented to reliably detecting physiological events, particularly for very small signals captured in the presence of significant background noise.

Abstract: A time domain reflectometry (TDR) impedance sensor is provided for measuring body impedance along a lead or catheter implanted in a patient's cardiovascular system. The TDR sensor applies an electrical stimulus to the lead and measures reflections echoed from impedance variations along and distal to the lead, which are superimposed on the applied stimulus. The measured signals may be analyzed with respect to time-of-flight and distance along the lead to detect a plurality of physiologically meaningful signals.

Abstract: A method and apparatus for selectively controlling an oscillator-driven implantable stimulator to operate either in a quiescent state, in response to a command from an external communicating device, or in an active state in response either to removal of an activation pin or to an activating command from an external communicating device. Upon completion of manufacture of the stimulator, and before being placed on a shelf to await implantation in a patient, the activation pin is inserted into the stimulator and the external communicating device is triggered to send a deactivating command to the stimulator. The stimulator responds by generally disabling current sources to stimulator circuits, while maintaining current sources to a wake up circuit of the stimulator that is associated with communication operations. The stimulator is activated by subsequently transmitting an activating command from an external communicating device to the implantable stimulator, or by removing the activation pin.