Abstract: In an example, an implantable medical device (IMD) includes a hold capacitor configured to deliver an electrical therapy pulse, and charge pump circuitry configured to transfer energy from the battery to the hold capacitor. In this example, the charge pump circuitry comprises a plurality of capacitors, and switching circuitry configured to put the charge pump circuitry into a K-factor mode selected from a group of K-factor modes by opening and closing a combination of switches connected to the plurality of capacitors.

Abstract: In some examples, the disclosure describes an implantable medical device comprising a plurality of electrodes, sensing circuitry configured to sense a physiological electrical signal via the plurality of electrodes, and communication circuitry configured to transmit and/or receive a transconductance communication signal via the plurality of electrodes, wherein at least one electrode of the plurality of electrodes comprises a lower-capacitance portion and a higher-capacitance portion.

Abstract: In some examples, an implantable medical device determines that another medical device delivered an anti-tachyarrhythmia shock, and delivers post-shock pacing in response to the determination. The implantable medical device may be configured to both detect the delivery of the shock in a sensed electrical signal and, if delivery of the shock is not detected, determine that the shock was delivered based on detection of asystole of the heart. The asystole may be detected based on the sensed electrical signal. In some examples, an implantable medical device is configured to revert from a post-shock pacing mode to a baseline pacing mode by iteratively testing a plurality of decreasing values of pacing pulse magnitude until loss of capture is detected. The implantable medical device may update a baseline value of the pacing pulse magnitude for the baseline mode based on the detection of loss of capture.

Abstract: In general, the disclosure is directed toward an implantable medical device that includes a plurality of sensor modules that are implanted within a patient. The sensor modules may cooperate with each other to coordinate the timing for performance of one or more sensor actions across the modules when making a measurement. Example measurements include tissue perfusion measurements, oxygen sensing measurements, sonomicrometry measurements, and pressure measurements. The coordination of the sensor modules may be controlled by a signal that is transmitted from a host controller to the sensor modules via a bus. In some examples, the bus may have two wires that transmit both timing information and data information to the sensor modules. The signal may be a signal that is substantially periodic, such as a pulsed signal. In additional examples, the signal may supply operating power and timing information to the sensor modules.

Abstract: A pressure sensing system provides signals representative of a magnitude of pressure at a selected site. A sensor module includes a first transducer producing a first signal having an associated first response to pressure and strain applied to the sensor module and a second transducer producing a second signal having an associated second response to pressure and strain applied to the sensor module. A calculated pressure, a bending pressure error and a bend-compensated pressure are computed in response to the first signal and the second signal.

Abstract: An implantable medical device comprising a signal generator configured to generate and deliver anti-tachyarrhythmia pacing (ATP) to a heart of a patient and processing circuitry. The processing circuitry is configured to detect an enable event, responsive to detecting the enable event, enable the delivery of ATP by the signal generator, detect a disable event indicating that another implantable medical device cannot be relied upon to deliver an anti-tachyarrhythmia shock, and responsive to detecting the disable event, disable delivery of ATP.

Abstract: An implantable medical device comprises a communication module that comprises at least one of a receiver module and a transmitter module. The receiver module is configured to both receive from an antenna and demodulate an RF telemetry signal, and receive from a plurality of electrodes and demodulate a tissue conduction communication (TCC) signal. The transmitter module is configured to modulate and transmit both an RF telemetry signal via the antenna and a TCC signal via the plurality of electrodes. The RF telemetry signal and the TCC signal are both within a predetermined band for RF telemetry communication. In some examples, the IMD comprises a switching module configured to selectively couple one of the plurality of electrodes and the antenna to the receiver module or transmitter module.

Abstract: An implantable medical device comprising a signal generator configured to generate and deliver anti-tachyarrhythmia pacing (ATP) to a heart of a patient and processing circuitry. The processing circuitry is configured to detect an enable event, responsive to detecting the enable event, enable the delivery of ATP by the signal generator, detect a disable event indicating that another implantable medical device cannot be relied upon to deliver an anti-tachyarrhythmia shock, and responsive to detecting the disable event, disable delivery of ATP.

Abstract: An implantable medical device comprises a communication module that comprises at least one of a receiver module and a transmitter module. The receiver module is configured to both receive from an antenna and demodulate an RF telemetry signal, and receive from a plurality of electrodes and demodulate a tissue conduction communication (TCC) signal. The transmitter module is configured to modulate and transmit both an RF telemetry signal via the antenna and a TCC signal via the plurality of electrodes. The RF telemetry signal and the TCC signal are both within a predetermined band for RF telemetry communication. In some examples, the IMD comprises a switching module configured to selectively couple one of the plurality of electrodes and the antenna to the receiver module or transmitter module.

Abstract: Implantable medical devices automatically switch from a normal mode of operation to an exposure mode of operation and back to the normal mode of operation. The implantable medical devices may utilize hysteresis timers in order to determine if entry and/or exit criteria for the exposure mode are met. The implantable medical devices may utilize additional considerations for entry to the exposure mode such as a confirmation counter or a moving buffer of sensor values. The implantable medical devices may utilize additional considerations for exiting the exposure mode of operation and returning to the normal mode, such as total time in the exposure mode, patient position, and high voltage source charge time in the case of devices with defibrillation capabilities.

Abstract: In some examples, an implantable medical device determines that another medical device delivered an anti-tachyarrhythmia shock, and delivers post-shock pacing in response to the determination. The implantable medical device may be configured to both detect the delivery of the shock in a sensed electrical signal and, if delivery of the shock is not detected, determine that the shock was delivered based on detection of asystole of the heart. The asystole may be detected based on the sensed electrical signal. In some examples, an implantable medical device is configured to revert from a post-shock pacing mode to a baseline pacing mode by iteratively testing a plurality of decreasing values of pacing pulse magnitude until loss of capture is detected. The implantable medical device may update a baseline value of the pacing pulse magnitude for the baseline mode based on the detection of loss of capture.

Abstract: An implantable medical device comprising a signal generator configured to generate and deliver anti-tachyarrhythmia pacing (ATP) to a heart of a patient and processing circuitry. The processing circuitry is configured to detect an enable event, responsive to detecting the enable event, enable the delivery of ATP by the signal generator, detect a disable event indicating that another implantable medical device cannot be relied upon to deliver an anti-tachyarrhythmia shock, and responsive to detecting the disable event, disable delivery of ATP.

Abstract: An implantable device system for delivering electrical stimulation pulses to a patient's body includes a pulse delivery device having a piezoelectric element that is enclosed by a housing and produces voltage signals delivered to the patient's body in response to receiving ultrasound energy. The pulse delivery device includes a circuit having a rate limiter configured to filter voltage signals produced by the piezoelectric element a rate faster than a maximum stimulation rate.

Abstract: Implantable medical systems enter an exposure mode of operation, either manually via a down linked programming instruction or by automatic detection by the implantable system of exposure to a magnetic disturbance. A controller then determines the appropriate exposure mode by considering various pieces of information including the device type including whether the device has defibrillation capability, pre-exposure mode of therapy including which chambers have been paced, and pre-exposure cardiac activity that is either intrinsic or paced rates. Additional considerations may include determining whether a sensed rate during the exposure mode is physiologic or artificially produced by the magnetic disturbance. When the sensed rate is physiologic, then the controller uses the sensed rate to trigger pacing and otherwise uses asynchronous pacing at a fixed rate.

Abstract: Implantable medical systems enter an exposure mode of operation, either manually via a down linked programming instruction or by automatic detection by the implantable system of exposure to a magnetic disturbance. A controller then determines the appropriate exposure mode by considering various pieces of information including the device type including whether the device has defibrillation capability, pre-exposure mode of therapy including which chambers have been paced, and pre-exposure cardiac activity that is either intrinsic or paced rates. Additional considerations may include determining whether a sensed rate during the exposure mode is physiologic or artificially produced by the magnetic disturbance. When the sensed rate is physiologic, then the controller uses the sensed rate to trigger pacing and otherwise uses asynchronous pacing at a fixed rate.

Abstract: An implantable device system for delivering electrical stimulation pulses to a patient's body includes a pulse delivery device having a piezoelectric element that is enclosed by a housing and produces voltage signals delivered to the patient's body in response to receiving ultrasound energy. The pulse delivery device includes a circuit having a rate limiter configured to filter voltage signals produced by the piezoelectric element a rate faster than a maximum stimulation rate.

Abstract: Electrical crosstalk between two implantable medical devices or two different therapy modules of a common implantable medical device may be evaluated, and, in some examples, mitigated. In some examples, one of the implantable medical devices or therapy modules delivers electrical stimulation to a nonmyocardial tissue site or a nonvascular cardiac tissue site, and the other implantable medical device or therapy module delivers cardiac rhythm management therapy to a heart of the patient.

Abstract: An implantable medical device system is configured to deliver cardiac pacing by receiving a cardiac electrical signal by sensing circuitry of a first device via a plurality of sensing electrodes, identifying by a control module of the first device a first cardiac event from the cardiac electrical signal, setting a first pacing interval in response to identifying the first cardiac event, controlling a power transmitter of the first device to transmit power upon expiration of the first pacing interval, receiving the transmitted power by a power receiver of a second device; and delivering at least a portion of the received power to a patient's heart via a first pacing electrode pair of the second device coupled to the power receiver.

Abstract: An implantable medical device system is configured to deliver cardiac pacing by receiving a cardiac electrical signal by sensing circuitry of a first device via a plurality of sensing electrodes, identifying by a control module of the first device a first cardiac event from the cardiac electrical signal, setting a first pacing interval in response to identifying the first cardiac event, controlling a power transmitter of the first device to transmit power upon expiration of the first pacing interval, receiving the transmitted power by a power receiver of a second device; and delivering at least a portion of the received power to a patient's heart via a first pacing electrode pair of the second device coupled to the power receiver.

Abstract: A medical device including an optical sensor is configured to measure an optical signal by integrating a current induced on a light detector of the optical sensor to obtain a voltage signal. The voltage signal is compared to a threshold. Responsive to the voltage signal reaching the threshold, an optical sensor control parameter is adjusted. The optical sensor is operated to produce the voltage signal using the adjusted control parameter.