Abstract: Described herein are methods for use with an implantable system including at least an atrial leadless pacemaker (aLP). Also described herein are specific implementations of an aLP, as well as implantable systems including an aLP. In certain embodiments, the aLP senses a signal from which cardiac activity associated with a ventricular chamber can be detected by the aLP itself based on feature(s) of the sensed signal. The aLP monitors the sensed signal for an intrinsic or paced ventricular activation within a ventricular event monitor window. In response to the aLP detecting an intrinsic or paced ventricular activation itself from the sensed signal within the ventricular event monitor window, the aLP resets an atrial escape interval timer that is used by the aLP to time delivery of an atrial pacing pulse if an intrinsic atrial activation is not detected within an atrial escape interval.

Abstract: Described herein are methods, devices, and systems for providing an implantable leadless pacemaker (LP) with a remote follow-up capability whereby the LP can provide diagnostic information to an external device that is incapable of programming the LP, wherein the LP includes two or more implantable electrodes used to output both pacing pulses and conductive communication pulses. Such a method can include the LP monitoring for a presence of one or more notification conditions associated with the LP and/or associated with a patient within which the LP is implanted, and the LP periodically outputting an advertisement sequence of pulses, using at least implantable electrodes of the LP, irrespective of whether the LP recognizes the presence of at least one notification condition. The method can also include the LP recognizing the presence of at least one notification condition, and based thereon, the LP also outputting a notification sequence of pulses.

Abstract: Described herein are methods, devices, and systems for providing an implantable leadless pacemaker (LP) with a remote follow-up capability whereby the LP can provide diagnostic information to an external device that is incapable of programming the LP, wherein the LP includes two or more implantable electrodes used to output both pacing pulses and conductive communication pulses. Such a method can include the LP monitoring for a presence of one or more notification conditions associated with the LP and/or associated with a patient within which the LP is implanted, and the LP periodically outputting an advertisement sequence of pulses, using at least implantable electrodes of the LP, irrespective of whether the LP recognizes the presence of at least one notification condition. The method can also include the LP recognizing the presence of at least one notification condition, and based thereon, the LP also outputting a notification sequence of pulses.

Abstract: Implantable medical devices (IMDs) described herein, and methods for use therewith described herein, reduce how often an IMD accepts a false message and/or reduce adverse effects of an IMD accepting a false message. Such IMDs can be leadless pacemakers (LPs), or implantable cardio defibrillators (ICDs), but are not limited thereto. Such embodiments can be used help multiple IMDs (e.g., multiple LPs) implanted within a same patient maintain synchronous operation, such as synchronous multi-chamber pacing.

Abstract: Implantable medical devices (IMDs) described herein, and methods for use therewith described herein, reduce how often an IMD accepts a false message and/or reduce adverse effects of an IMD accepting a false message. Such IMDs can be leadless pacemakers (LPs), or implantable cardio defibrillators (ICDs), but are not limited thereto. Such embodiments can be used help multiple IMDs (e.g., multiple LPs) implanted within a same patient maintain synchronous operation, such as synchronous multi-chamber pacing.

Abstract: Embodiments described herein relate to implantable medical devices (IMDs) and methods for use therewith. Such a method includes, during each of a plurality of message alert periods during which a communication capability of the IMD is enabled, determining whether a valid message is detected. In response to determining that no valid message was detected during a message alert period, the communication capability of the IMD is temporarily disable for a disable period. A length of the disable period may be increased in response to no valid message being detected during two consecutive message alert periods. A length of the disable period may be dependent on an operational mode of the IMD, such that the length of the disable period differs for different operational modes. The IMD may also enter a noise state, and remain in the noise state until the IMD receives a specified number of valid messages.

Abstract: Described herein is a fully-differential preamplifier comprising an input differential pair, an output current load, and a current source. The current source is coupled between the input differential pair and a low voltage rail and configured to control whether the fully-differential preamplifier is operating in a first mode or a second mode, wherein the preamplifier draws more current when operating in the second mode compared to when operating in the first mode. The input differential pair is coupled between the output current load and the current source. The output current load is coupled between a high voltage rail and the input differential pair. The input differential pair comprise positive and negative inputs of the fully-differential preamplifier. Nodes where the input differential pair and the output current load are coupled to one another comprise positive and negative outputs of the fully-differential preamplifier.

Abstract: Described herein is a fully-differential receiver for use with an implantable medical device (IMD) and configured to receive conducted communication signals that are transmitted by another IMD or an external device. The fully-differential receiver includes a fully-differential preamplifier, a fully-differential buffer, a first comparator, a second comparator, and an AC coupling network coupled between differential outputs of the fully-differential buffer and a coupled together differential pair of inputs of the first and second comparators. A differential pair of inputs of the fully-differential receiver comprise the differential pair of inputs of the fully-differential preamplifier, and a differential pair of outputs of the fully-differential receiver comprise a first output of the first comparator and a second output of the second comparator. In order to conserve power, the fully-differential receiver is selectively changed from operating in a first mode to operating in a second mode, and vice versa.

Abstract: Described herein is a fully-differential preamplifier comprising an input differential pair, an output current load, and a current source. The current source is coupled between the input differential pair and a low voltage rail and configured to control whether the fully-differential preamplifier is operating in a first mode or a second mode, wherein the preamplifier draws more current when operating in the second mode compared to when operating in the first mode. The input differential pair is coupled between the output current load and the current source. The output current load is coupled between a high voltage rail and the input differential pair. The input differential pair comprise positive and negative inputs of the fully-differential preamplifier. Nodes where the input differential pair and the output current load are coupled to one another comprise positive and negative outputs of the fully-differential preamplifier.

Abstract: Implantable medical devices (IMDs) described herein, and methods for use therewith described herein, reduce how often an IMD accepts a false message and/or reduce adverse effects of an IMD accepting a false message. Such IMDs can be leadless pacemakers (LPs), or implantable cardio defibrillators (ICDs), but are not limited thereto. Such embodiments can be used help multiple IMDs (e.g., multiple LPs) implanted within a same patient maintain synchronous operation, such as synchronous multi-chamber pacing.

Abstract: Described herein are methods, devices, and systems that enable a remote non-implantable device (RNID) to send commands to a leadless pacemaker (LP) implanted within a patient. The RNID provide commands to a local non-implantable device (LNID) over one or more communication networks, and the LNID sends the commands to a second implantable device (SID) by transmitting radio frequency (RF) communication signals, which include the commands, using an antenna of the LNID. After receiving the commands from the LNID, by receiving RF communication signals that include the commands using an antenna of the SID, the SID transmits conductive communication signals, which include the commands, using electrodes of the SID. The LP receives the commands from the SID by receiving the conductive communication signals, which include the commands, using electrodes of the LP, and the LP performs command responses based on the commands that originated from the RNID.

Abstract: Described herein are external devices, and methods for use therewith, that are configured to communicate with one or more implantable medical devices (IMDs) implanted within a patient using conductive communication, wherein the external device includes or is communicatively coupled to at least three external electrodes that are in contact with the patient. Certain such methods involve the external device identifying, for each IMD, of the plurality of IMDs, which one of the plurality of communication vectors is a preferred communication vector for communicating with the IMD, based on respective indicators of conductive communication quality that are determined for the plurality of communication vectors. Certain embodiments involve determining when there should be a reassessment of which one of the plurality of communication vectors is the preferred communication vector for communicating with an IMD, and in response thereto, identifying an updated preferred communication vector for communicating with the IMD.

Abstract: Described herein is an implantable medical device (IMD) that wirelessly communicates another IMD, and methods for use therewith. Such a method can include receiving one or more implant-to-implant (i2i) communication signals from the other IMD using a communication receiver of the IMD, measuring a strength of at least one of the one or more received i2i communication signals or a surrogate thereof, and updating a strength metric based on the measured strength or surrogate thereof. The method further includes determining, based on the updated strength metric, whether to increase, decrease, or maintain the sensitivity of the communication receiver of the IMD, and responding accordingly such that the sensitivity is sometimes increased, sometimes decreased, and sometimes maintained. The method can also include selectively causing a transmitter of the IMD to transmit an i2i communication signal to the other IMD requesting that the other IMD adjust its transmission strength.

Abstract: Described herein are methods for use with an implantable system including at least an atrial leadless pacemaker (aLP). Also described herein are specific implementations of an aLP, as well as implantable systems including an aLP. In certain embodiments, the aLP senses a signal from which cardiac activity associated with a ventricular chamber can be detected by the aLP itself based on feature(s) of the sensed signal. The aLP monitors the sensed signal for an intrinsic or paced ventricular activation within a ventricular event monitor window. In response to the aLP detecting an intrinsic or paced ventricular activation itself from the sensed signal within the ventricular event monitor window, the aLP resets an atrial escape interval timer that is used by the aLP to time delivery of an atrial pacing pulse if an intrinsic atrial activation is not detected within an atrial escape interval.

Abstract: Embodiments described herein relate to implantable medical devices (IMDs) and methods for use therewith. Such a method includes, during each of a plurality of message alert periods during which a communication capability of the IMD is enabled, determining whether a valid message is detected. In response to determining that no valid message was detected during a message alert period, the communication capability of the IMD is temporarily disable for a disable period. A length of the disable period may be increased in response to no valid message being detected during two consecutive message alert periods. A length of the disable period may be dependent on an operational mode of the IMD, such that the length of the disable period differs for different operational modes. The IMD may also enter a noise state, and remain in the noise state until the IMD receives a specified number of valid messages.

Abstract: Described herein are methods, devices, and systems for providing an implantable leadless pacemaker (LP) with a remote follow-up capability whereby the LP can provide diagnostic information to an external device that is incapable of programming the LP, wherein the LP includes two or more implantable electrodes used to output both pacing pulses and conductive communication pulses. Such a method can include the LP monitoring for a presence of one or more notification conditions associated with the LP and/or associated with a patient within which the LP is implanted, and the LP periodically outputting an advertisement sequence of pulses, using at least implantable electrodes of the LP, irrespective of whether the LP recognizes the presence of at least one notification condition. The method can also include the LP recognizing the presence of at least one notification condition, and based thereon, the LP also outputting a notification sequence of pulses.

Abstract: Described herein are methods, devices, and systems for providing an implantable leadless pacemaker (LP) with a remote follow-up capability whereby the LP can provide diagnostic information to an external device that is incapable of programming the LP, wherein the LP includes two or more implantable electrodes used to output both pacing pulses and conductive communication pulses. Such a method can include the LP monitoring for a presence of one or more notification conditions associated with the LP and/or associated with a patient within which the LP is implanted, and the LP periodically outputting an advertisement sequence of pulses, using at least implantable electrodes of the LP, irrespective of whether the LP recognizes the presence of at least one notification condition. The method can also include the LP recognizing the presence of at least one notification condition, and based thereon, the LP also outputting a notification sequence of pulses.

Abstract: Embodiments described herein relate to implantable medical devices (IMDs) and methods for use therewith. Such a method includes enabling a communication capability of an IMD during a message alert period and monitoring for a message while the communication capability is enabled during the message alert period. In response to receiving a message during the message alert period, there is a determination whether the message is valid or invalid. If the message is invalid, the message is ignored, and an invalid message count is incremented. A further message is monitored for during the message alert period occurs, when the invalid message count has not yet reached a corresponding invalid message count threshold. The communication capability of the IMD is disabled for a disable period, when the invalid message count reaches the corresponding invalid message count threshold. If a valid message is received, the IMD acts upon information included therein.

Abstract: The present disclosure provides systems and methods for classifying signals of interest in a cardiac rhythm management (CRM) device. A CRM device includes an intrinsic activation sensing circuit configured to pass signals falling within a first passband, a crosstalk sensing circuit configured to pass signals falling within a second passband, wherein the second passband contains higher frequencies than the first passband, and a computing device communicatively coupled to the intrinsic activation sensing circuit and the crosstalk sensing circuit, the computing device configured to classify a signal of interest as one of an intrinsic activation signal and a crosstalk signal based on whether the signal of interest is passed by the intrinsic activation sensing circuit and the crosstalk sensing circuit.

Abstract: Implantable medical devices (IMDs) described herein, and methods for use therewith described herein, reduce how often an IMD accepts a false message and/or reduce adverse effects of an IMD accepting a false message. Such IMDs can be leadless pacemakers (LPs), or implantable cardio defibrillators (ICDs), but are not limited thereto. Such embodiments can be used help multiple IMDs (e.g., multiple LPs) implanted within a same patient maintain synchronous operation, such as synchronous multi-chamber pacing.