Abstract: Systems, devices, and methods are disclosed for limiting the duration of elevated pacing rates in an implantable medical device. An illustrative device may include a housing, a plurality of electrodes connected to the housing, and a controller within the housing and connected to the electrodes. The controller may deliver pacing pulses to the electrodes at a base pacing rate, detect a measure of elevated metabolic demand which may vary over time, deliver pacing pulses at an elevated pacing rate based on the measure of elevated metabolic demand. The controller may change a heart stress tracking value (HSTV) when the pacing rate is elevated and may be changed faster during times of relatively higher elevated pacing rates than times of relatively lower elevated pacing rates. The elevated pacing rate may be reduced back toward the base pacing rate after the HSTV crossed a predetermined heart stress threshold.

Abstract: Systems, methods, and devices for detecting or confirming fibrillation are discussed. In one example, a method for detecting a cardiac arrhythmia of a patients' heart comprises receiving, by a leadless cardiac pacemaker fixed in the patients' heart, an indication from a remote device that a cardiac arrhythmia is detected, monitoring by the leadless cardiac pacemaker a signal generated by a sensor that is located within the patients' heart, and based at least in part on the monitored signal, confirming whether a cardiac arrhythmia is occurring or not. In some embodiments, the method may further comprise, if a cardiac arrhythmia is confirmed, delivering a therapy to treat the cardiac arrhythmia.

Abstract: Methods and devices for configuring the use of a motion sensor in an implantable cardiac device. The electrical signals of the patient's heart are observed and may be correlated to the physical motion of the heart as detected by the motion sensor of the implantable cardiac device in order to facilitate temporal configuration of motion sensor data collection that avoids detecting cardiac motion in favor of overall motion of the patient.

Abstract: Implantable devices having motion sensors. In some examples the a configuration is generated for the implantable device to use the motion sensor in an energy preserving mode in which one or more axis of detection of the motion sensor is disabled or ignored. In some examples the motion sensor outputs along multiple axes are analyzed to determine which axes best correspond to certain patient parameters including patient motion/activity and/or cardiac contractility. In other examples the output of the motion sensor is observed across patient movements or postures to develop conversion parameters to determine a patient standard frame of reference relative to outputs of the motion sensor of an implanted device.

Abstract: Systems, devices, and methods for pacing a heart of a patient are disclosed. In some embodiments, a method for pacing a patient's heart may include determining a posture of the patient and determining if the determined posture corresponds to a predetermined sleep posture. If the determined posture correspond to the predetermined sleep posture, the method may further comprise determining a respiration phase of the patient and pacing the patient's heart at a pacing rate that is modulated based on the determined respiration phase of the patient. If the determined posture does not correspond to the predetermined sleep posture, the method may pace the patient's heart at a pacing rate that is not dependent on the respiration phase of the patient.

Abstract: Systems, devices, and methods for adjusting functionality of an implantable medical device based on posture are disclosed. In some instances, a method for operating a leadless cardiac pacemaker implanted into a patient, where the patient has two or more predefined behavioral states, may include detecting a change in the behavioral state of the patient, and in response, changing a sampling rate of a sensor signal generated by a sensor of the leadless cardiac pacemaker. In some embodiments, the method may further include using the sampled sensor signal to determine an updated pacing rate of the leadless cardiac pacemaker and providing pacing to the patient at the updated pacing rate.

Abstract: Medical device systems and methods with multiple communication modes. An example medical device system may include a first medical device and a second medical device communicatively coupled to the first medical device. The first medical device may be configured to communicate information to the second medical device in a first communication mode. The first medical device may further be configured to communicate information to the second medical device in a second communication mode after determining that one or more of the communication pulses captured the heart of the patient.

Abstract: An implantable cardiac rhythm system includes a first implantable medical device configured to detect a first heartbeat from a first location, and a second implantable medical device configured to detect the first heart beat of the patient from a second location. The second implantable medical device, upon detecting the first heart beat, may communicate an indication of the detected first heart beat to the first implantable medical device, and in response, the first implantable medical device may institute a blanking period having a blanking period duration such that a T-wave of the detected first heart beat is blanked out by the first implantable medical device so as to not be interpreted as a subsequent second heart beat. In some instances, the first implantable medical device is an SICD and the second implantable medical device is a LCP.

Abstract: System and methods for energy adaptive communications between medical devices are disclosed. In one example, a medical device includes a communication module configured to deliver a plurality of pulses to tissue of a patient, where each pulse has an amount of energy. A control module operatively coupled to the communication module, may be configured to, for each delivered pulse, determine whether the delivered pulse produces an unwanted stimulation of the patient and to change the amount of energy of the plurality of pulses over time so as to identify an amount of energy that corresponds to an unwanted stimulation threshold for the pulses. The control module may then set a maximum energy value for communication pulses that is below the unwanted stimulation threshold, and may deliver communication pulses below the maximum energy value during communication with another medical device.

Abstract: Self-correlation enhancements and implementations are described. In particular, certain examples demonstrate the analytical tools to reduce the computational burden of generating a self-correlation function within an implantable medical device. Peak selector and tracking analysis are also included as secondary elements for identifying and generating confidence in rate estimates based on the self-correlation function. The approach may enable an alternative calculation of cardiac rate in an implantable medical device as a stand-alone rate detector or as a double-check of other rate calculations.

Abstract: System and methods for energy adaptive communications between medical devices are disclosed. In one example, a medical device includes a communication module configured to deliver a plurality of pulses to tissue of a patient, where each pulse has an amount of energy. A control module operatively coupled to the communication module, may be configured to, for each delivered pulse, determine whether the delivered pulse produces an unwanted stimulation of the patient and to change the amount of energy of the plurality of pulses over time so as to identify an amount of energy that corresponds to an unwanted stimulation threshold for the pulses. The control module may then set a maximum energy value for communication pulses that is below the unwanted stimulation threshold, and may deliver communication pulses below the maximum energy value during communication with another medical device.

Abstract: Systems and methods for treating arrhythmias are disclosed. In one embodiment an LCP comprises a housing, a plurality of electrodes for sensing electrical signals emanating from outside of the housing, an energy storage module disposed within the housing, and a control module disposed within the housing and operatively coupled to the plurality of electrodes. The control module may be configured to receive electrical signals via two or more of the plurality of electrodes and determine if the received electrical signals are indicative of a command for the LCP to deliver ATP therapy. If the received electrical signals are indicative of a command for the LCP to deliver ATP therapy, the control module may additionally determine whether a triggered ATP therapy mode of the LCP is enabled. If the triggered ATP therapy mode is enabled, the control module may cause the LCP to deliver ATP therapy via the plurality of electrodes.

Abstract: An implantable medical device comprises a non-volatile memory circuit including a configuration memory portion to store auto-configuration data for the IMD, a controller circuit, a reset circuit adapted to generate a reset signal and disable the controller circuit, and a startup circuit adapted to transfer the auto-configuration data from the configuration memory portion to one or more configuration registers in response to the reset signal, wherein values of the one or more configuration registers configure the IMD for a safety mode operation.

Abstract: An implantable cardiac rhythm system includes a first implantable medical device configured to detect a first heartbeat from a first location, and a second implantable medical device configured to detect the first heart beat of the patient from a second location. The second implantable medical device, upon detecting the first heart beat, may communicate an indication of the detected first heart beat to the first implantable medical device, and in response, the first implantable medical device may institute a blanking period having a blanking period duration such that a T-wave of the detected first heart beat is blanked out by the first implantable medical device so as to not be interpreted as a subsequent second heart beat. In some instances, the first implantable medical device is an SICD and the second implantable medical device is a LCP.

Abstract: System and methods for energy adaptive communications between medical devices are disclosed. In one example, a medical device includes a communication module configured to deliver a plurality of pulses to tissue of a patient, where each pulse has an amount of energy. A control module operatively coupled to the communication module, may be configured to, for each delivered pulse, determine whether the delivered pulse produces an unwanted stimulation of the patient and to change the amount of energy of the plurality of pulses over time so as to identify an amount of energy that corresponds to an unwanted stimulation threshold for the pulses. The control module may then set a maximum energy value for communication pulses that is below the unwanted stimulation threshold, and may deliver communication pulses below the maximum energy value during communication with another medical device.

Abstract: A cardiac rhythm management system includes a first implantable device such as a defibrillator and a second implantable device such as a leadless cardiac pacemaker. A programmer is configured to receive and display heart data emanating from the implantable defibrillator and from the leadless cardiac pacemaker. The heart data emanating from the leadless cardiac pacemaker is displayed in temporal alignment with the heart data emanating from the implantable defibrillator.

Abstract: Self-correlation enhancements and implementations are described. In particular, certain examples demonstrate the analytical tools to reduce the computational burden of generating a self-correlation function within an implantable medical device. Peak selector and tracking analysis are also included as secondary elements for identifying and generating confidence in rate estimates based on the self-correlation function. The approach may enable an alternative calculation of cardiac rate in an implantable medical device as a stand-alone rate detector or as a double-check of other rate calculations.

Abstract: Systems and methods for communicating between medical devices. In one example, an implantable medical device comprising may comprise one or more electrodes and a controller coupled to the electrodes. The controller may be configured to receive a first communication pulse at a first communication pulse time and a second communication pulse at a second communication pulse time via the one or more electrodes. The controller may further be configured to identify one of three or more symbols based at least in part on the time difference between the first communication pulse time and the second communication pulse time.

Abstract: Systems and methods for communicating between medical devices. In one example, a method for communicating between a plurality of medical devices in a medical device system comprises, with a first medical device, communicating a first message to a second medical device. The method further comprises, with the second medical device, receiving the first message, wherein the first message comprises a plurality of communication pulses. A first set of the plurality of communication pulses represent a synchronization portion of the first message. A second set of the plurality of communication pulses represent a relative device address portion of the first message. A third set of the plurality of communication pulses represent a command portion of the first message. A fourth set of the plurality of communication pulses represent a payload portion of the first message.

Abstract: Medical device systems and methods with multiple communication modes. An example medical device system may include a first medical device and a second medical device communicatively coupled to the first medical device. The first medical device may be configured to communicate information to the second medical device in a first communication mode. The first medical device may further be configured to communicate information to the second medical device in a second communication mode after determining that one or more of the communication pulses captured the heart of the patient.