Abstract: Systems, devices, and techniques for establishing communication between two medical devices are described. In one example, an implantable medical device comprises communication circuitry, therapy delivery circuitry, and processing circuitry configured to initiate a communication window during which the implantable second medical device is capable of receiving the information related to a cardiac event detected by a first medical device, the communication window being one of a plurality of communication windows defined by a communication schedule that corresponds to a transmission schedule in which the first medical device is configured to transmit the information, control the communication circuitry to receive, from the first medical device, the information related to the cardiac event that is indicative of a timing of the cardiac event with respect to a timing of the communication window, schedule and control delivery of a therapy according to the information related to the cardiac event.

Abstract: A pacemaker is configured to operate in an atrial synchronous ventricular pacing mode and, after expiration of a conduction check time interval, switch to an asynchronous ventricular pacing mode that includes setting a ventricular pacing interval to a base pacing rate interval. The pacemaker is further configured to determine when atrioventricular block detection criteria are satisfied during the asynchronous ventricular pacing mode and, responsive to the atrioventricular block detection criteria being satisfied, switch back to the atrial synchronous ventricular pacing mode.

Abstract: A pacemaker is configured to operate in an atrial synchronous ventricular pacing mode and, after expiration of a conduction check time interval, switch to an asynchronous ventricular pacing mode that includes setting a ventricular pacing interval to a base pacing rate interval. The pacemaker is further configured to determine when atrioventricular block detection criteria are satisfied during the asynchronous ventricular pacing mode and, responsive to the atrioventricular block detection criteria being satisfied, switch back to the atrial synchronous ventricular pacing mode.

Abstract: Techniques are disclosed for adjusting event detection parameters used for sensing mechanical motion data of a heart of a patient for use in cardiac pacing therapy. For example, processing circuitry receives, from a user, an input specifying one or more event detection parameters defining mechanical motion sensing of a heart of a patient by one or more motion sensors of an implantable medical device (IMD). The processing circuitry controls the IMD to perform mechanical motion sensing of the heart of the patient in accordance with the one or more event detection parameters. The processing circuitry obtains mechanical motion data of the heart of the patient sensed in accordance with the one or more event detection parameters. The processing circuitry controls the IMD to deliver cardiac pacing therapy based on the mechanical motion data of the heart of the patient sensed in accordance with the one or more event detection parameters.

Abstract: Systems, devices, and techniques for establishing communication between two medical devices are described. In one example, an implantable medical device comprises communication circuitry, therapy delivery circuitry, and processing circuitry configured to initiate a communication window during which the implantable second medical device is capable of receiving the information related to a cardiac event detected by a first medical device, the communication window being one of a plurality of communication windows defined by a communication schedule that corresponds to a transmission schedule in which the first medical device is configured to transmit the information, control the communication circuitry to receive, from the first medical device, the information related to the cardiac event that is indicative of a timing of the cardiac event with respect to a timing of the communication window, schedule and control delivery of a therapy according to the information related to the cardiac event.

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: Systems, devices, and techniques for establishing communication between two medical devices are described. In one example, an implantable medical device comprises communication circuitry, therapy delivery circuitry, and processing circuitry configured to initiate a communication window during which the implantable second medical device is capable of receiving the information related to a cardiac event detected by a first medical device, the communication window being one of a plurality of communication windows defined by a communication schedule that corresponds to a transmission schedule in which the first medical device is configured to transmit the information, control the communication circuitry to receive, from the first medical device, the information related to the cardiac event that is indicative of a timing of the cardiac event with respect to a timing of the communication window, schedule and control delivery of a therapy according to the information related to the cardiac event.

Abstract: A pacemaker is configured to operate in an atrial synchronous ventricular pacing mode and, after expiration of a conduction check time interval, switch to an asynchronous ventricular pacing mode that includes setting a ventricular pacing interval to a base pacing rate interval. The pacemaker is further configured to determine when atrioventricular block detection criteria are satisfied during the asynchronous ventricular pacing mode and, responsive to the atrioventricular block detection criteria being satisfied, switch back to the atrial synchronous ventricular pacing mode.

Abstract: A system and method is provided for reliably indicating that an implantable medical device is in need of replacement. An implantable medical device includes a battery and a replacement indicator timer. The battery provides power to the implantable medical device. The replacement indicator timer counts a replacement time period to a determined replacement date for the implantable medical device. The replacement indicator timer starts the counting when an operational characteristic of the battery reaches a selected value.

Abstract: Systems, devices, and techniques for establishing communication between two medical devices are described. In one example, an implantable medical device comprises communication circuitry, therapy delivery circuitry, and processing circuitry configured to initiate a communication window during which the implantable second medical device is capable of receiving the information related to a cardiac event detected by a first medical device, the communication window being one of a plurality of communication windows defined by a communication schedule that corresponds to a transmission schedule in which the first medical device is configured to transmit the information, control the communication circuitry to receive, from the first medical device, the information related to the cardiac event that is indicative of a timing of the cardiac event with respect to a timing of the communication window, schedule and control delivery of a therapy according to the information related to the cardiac event.

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: Methods for estimating a remaining service life of an implantable medical device (IMD) battery are presented. In one embodiment, a characteristic discharge model of the battery is employed. Systems employing the methods may include an external device coupled to the IMD, for example, via a telemetry communications link, wherein a first portion of a computer readable medium included in the IMD is programmed to provide instructions for the measurement, or tracking, of time and the measurement of battery voltage, and a second portion of the computer readable medium included in the external device is programmed to provide instructions for carrying out the calculations when the voltage and time data is transferred via telemetry from the IMD to the external device.

Abstract: In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or “LV”) can be used to infer capture or loss-of-capture (LOC) of an earlier stimulus pulse in the same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and/or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and/or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.

Abstract: Methods for estimating a remaining service life of an implantable medical device (IMD) battery are presented. In one embodiment, a characteristic discharge model of the battery is employed. Systems employing the methods may include an external device coupled to the IMD, for example, via a telemetry communications link, wherein a first portion of a computer readable medium included in the IMD is programmed to provide instructions for the measurement, or tracking, of time and the measurement of battery voltage, and a second portion of the computer readable medium included in the external device is programmed to provide instructions for carrying out the calculations when the voltage and time data is transferred via telemetry from the IMD to the external device.

Abstract: In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or “LV”) can same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and/or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and/or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.

Abstract: In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or “LV”) can be used to infer capture or loss-of-capture (LOC) of an earlier stimulus pulse in the same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and/or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and/or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.

Abstract: Methods for estimating a remaining service life of an implantable medical device (IMD) battery employ calculations using a characteristic discharge model of the battery; the calculations require measurements of battery voltage and time. Systems employing the methods may include an external device coupled to the IMD, for example, via a telemetry communications link, wherein a first portion of a computer readable medium included in the IMD is programmed to provide instructions for the measurement, or tracking, of time and the measurement of battery voltage, and a second portion of the computer readable medium included in the external device is programmed to provide instructions for carrying out the calculations when the voltage and time data is transferred via telemetry from the IMD to the external device.

Abstract: A capture detection algorithm detects and distinguishes atrial capture. Atrial chamber reset (ACR) and AV conduction (AVC) algorithms are implemented to measure an atrial pacing threshold The data that is used to choose between ACR and AVC methods is used to determine the progression of the patient's disease state. Some of the significant aspects of the invention include enablement of accurate threshold measurements, including calculation of stability criteria, precise interval measurements and the use of reference interval to determine capture and loss of capture.

Abstract: A system and method is provided for reliably indicating that an implantable medical device is in need of replacement. The system and method measures the operational characteristics of the battery and the operational parameters of the implantable device itself. When these characteristics and parameters reach a defined level, the implantable medical device starts a replacement indicator timer. The replacement indicator timer starts and counts a replacement time period, with the replacement time period ending at a determined replacement date. The determined replacement date is the date at which the implantable medical device should be replaced.

Abstract: A system and method is provided for reliably indicating that an implantable medical device is in need of replacement. The system and method measures the operational characteristics of the battery and the operational parameters of the implantable device itself. When these characteristics and parameters reach a defined level, the implantable medical device starts a replacement indicator timer. The replacement indicator timer starts and counts a replacement time period, with the replacement time period ending at a determined replacement date. The determined replacement date is the date at which the implantable medical device should be replaced.