Abstract: An implantable medical device system and method are provided for synchronizing atrial cardioversion shocks to the ventricular rhythm using an adjustable atrial cardioversion/defibrillation ventricular refractory period. Upon determining a need for an atrial shock therapy, the method determines if the ventricular rate meets synchronization criteria based on an upper ventricular refractory period limit. If synchronization criteria are not met, the refractory period is automatically adjusted in stepwise decrements until the synchronization criteria are met, or until a lower refractory period limit is exceeded. If synchronization criteria are met, an atrial shock is synchronized to the next ventricular depolarization occurring outside the current refractory period. If the lower refractory period limit is exceeded, the atrial therapy is aborted.

Abstract: An implantable medical device (IMD) provides an alert to a patient that has the IMD implanted in their body. The alert is used to remind the patient to schedule and/or proceed to a follow-up physician visit. The reminder is also used to remind the patient to initiate a remote communication so that stored data or other information may be transmitted to a remote computer network or other communication node.

Abstract: A method and apparatus for providing a therapy to the patient that includes a therapy component configured to provide the therapy to the patient, sensing circuitry sensing a parameter of the patient, and a microprocessor coupled to the therapy component and the sensing circuitry to determine onset of a first state of the patient in response to the sensed physiologic parameter, and to determine whether the onset of the first state is detected for a predetermined time period.

Abstract: A system and method for monitoring respiration including sensing a signal that varies with respiration, deriving a respiration parameter, applying criteria for detecting a respiration disturbance and determining one or more respiratory disturbance metrics. The system preferably includes an implantable sensor with an associated implantable medical device such that chronic respiration monitoring is possible. The implantable medical device may execute methods for detecting and measuring respiratory disturbances or may store data to be transferred to an external device for detecting and measuring respiratory disturbances. Respiratory disturbance detection may trigger a responsive action such as physiological data storage, a change in therapy delivery, or a clinician warning. Assessment of cardiac function may be made based on metrics of respiratory disturbances or a measure of circulatory delay time following detection of a respiratory disturbance.

Abstract: Techniques for increase the accuracy of detection of atrial capture may involve determining a ventricular sensing window for ventricular senses associated with atrial test pulses based on observed ventricular senses. For example, an implanted medical device may deliver atrial test pulses to a patient at a time prior to respective atrial pacing pulses to evaluate atrial capture. The implanted medical device observes ventricular senses in response to the atrial test pulses. The implanted medical device may determine a point such as, for example, a midpoint of the ventricular sensing window for the ventricular senses and shift a midpoint of the default ventricular window to the determined midpoint. Further, the implanted medical device may measure patient parameters, such as heart rate and activity level, and determine a ventricular sensing window for ventricular senses associated with atrial test pulses based on the observed ventricular senses and measured patient parameters.

Abstract: An implantable device is described that collects and aggregates data from non-implanted medical devices external from a body of a patient. The device may also collect and aggregate data from medical devices implanted within the body. The implantable device includes a wireless transceiver to acquire physiological data from the external medical devices, and a storage medium to store the physiological data. A processor retrieves the physiological data and communicates the physiological data to a remote patient management system. The device may collect the physiologic data from the various external data sources, possibly over an extended period of time, and stores the data for subsequent upload to a common patient management system. In addition, the implantable device may collect physiological data from other medical devices implanted within the patient. In this manner, the device provides a central point for collection and aggregation of physiological data relating to the patient.

Abstract: An implantable medical device system is described including an implantable medical device for implantation in a patient. One embodiment of the implantable medical device includes a therapy component for providing a therapy to the patient, a minute ventilation (MV) sensing circuit producing MV values indicative of a MV of the patient at time intervals, and computational circuitry. The computational circuitry receives a number of the MV values over a period of time, calculates a statistical parameter (e.g., a mean) of the MV values, and calculates a deviation of the MV values from the statistical parameter (e.g., a standard deviation of the MV values). The computational circuitry detects an onset of sleep in the patient when the deviation of the MV values from the statistical parameter is less than a predetermined MV threshold value, and signals the therapy component to modify the therapy when the onset of sleep is detected in the patient.

Abstract: The present invention provides a method and apparatus for detecting and treating sleep respiratory events that includes a plurality of sensors gathering physiological data related to sleep respiratory events. A processor extracts an average cycle length and a frequency of at least one of Cheyne-Stokes respiration and periodic breathing based upon the physiological data, and determines whether therapy is required based on the average cycle length and the frequency.

Abstract: The present invention provides a method and apparatus for detecting and treating sleep respiratory events that includes a plurality of sensors gathering physiological data related to sleep respiratory events. A processor extracts an average cycle length and a frequency of at least one of Cheyne-Stokes respiration and periodic breathing based upon the physiological data, and determines whether therapy is required based on the average cycle length and the frequency.

Abstract: A method and an apparatus for performing implementing external data into an implantable medical device. A first stress test is performed using an external sensor. External data resulting from the initial stress test is acquired. An external data injection process is performed. The external data injection process includes providing the external data to the implantable medical device. A second stress test is performed, the second stress test being substantially similar to the first stress test. Internal data resulting from the second stress test is acquired. Internal data resulting from the second stress test along with the external data resulting from the first stress test, are processed.

Abstract: A method and an apparatus for performing rate responsive control in an implantable medical device using a scaling factor. Sensor data is acquired using a sensor operatively coupled with the implantable medical device. At least one setpoint for controlling a rate of therapy is generated, the setpoint being based upon the sensor data. A scaling factor adjustment process is performed for scaling the internal sensor data to correlate the sensor data to the setpoint. The rate of therapy is adjusted based upon the scaling factor adjustment.

Abstract: Methods and devices for determining optimal Atrial to Ventricular (AV) pacing intervals and Ventricular to Ventricular (VV) delay intervals in order to optimize cardiac output. Impedance, preferably sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change.

Abstract: Primarily, the invention relates to a safe delivery of atrial cardioversion pulses in complex cardiac therapy environments wherein cardiac events suggest, for example, rapid ventricular rates that would prevent a safe atrial cardioversion. The invention generally utilizes an algorithmic system in which a resultant R-R interval encountered subsequent to the delivery of a ventricular pacing pulse is decrementally scanned until an R-R interval is found that will yield a reliable sustained R-R interval. The sustenance of the R-R interval prolongation enables ventricular deceleration. Strategically selected timing windows are used to trigger a device response that is proper and tailored to the ventricular event detected during and within the timing windows. Further, the invention enables an atrial cardioversion synchronization method that allows for the safe delivery of atrial cardioversion pulses in the presence of very rapid ventricular rates.

Abstract: An implantable medical device system is described including an implantable medical device for implantation in a patient. One embodiment of the implantable medical device includes a therapy component for providing a therapy to the patient, a minute ventilation (MV) sensing circuit producing MV values indicative of a MV of the patient at time intervals, and computational circuitry. The computational circuitry receives a number of the MV values over a period of time, calculates a statistical parameter (e.g., a mean) of the MV values, and calculates a deviation of the MV values from the statistical parameter (e.g., a standard deviation of the MV values). The computational circuitry detects an onset of sleep in the patient when the deviation of the MV values from the statistical parameter is less than a predetermined MV threshold value, and signals the therapy component to modify the therapy when the onset of sleep is detected in the patient.

Abstract: The present invention provides a method and apparatus for detecting and treating sleep respiratory events that includes a plurality of sensors gathering physiological data related to sleep respiratory events. A processor extracts an average cycle length and a frequency of at least one of Cheyne-Stokes respiration and periodic breathing based upon the physiological data, and determines whether therapy is required based on the average cycle length and the frequency.

Abstract: An implantable anti-tachyarrhythmia device which delivers atrial cardioversion or defibrillation pulses heart in response to detection of atrial tachyarrhythmias. The pulses are synchronized to atrial and ventricular events in such a fashion as to assure they occur outside of the vulnerable periods associated with both chambers.

Abstract: A cardiac pacemaker and a method of its use. The pacemaker paces a patient's heart in a tachyarrhythmia prevention pacing mode for an extended time period, defines a metric of success of the tachyarrhythmia prevention pacing mode, monitors the metric over the extended time period and, responsive to the monitored metric, adjusts the tachyarrhythmia prevention pacing mode. Adjustment of the tachyarrhythmia prevention pacing mode may take the form of pacing the patient's heart with a different set of electrodes, pacing the patient's heart with a different tachyarrhythmia prevention pacing mode and/or terminating operation of the tachyarrhythmia prevention pacing mode.

Abstract: An implantable anti-tachyarrhythmia device which delivers atrial cardioversion or defibrillation pulses heart in response to detection of atrial tachyarrhythmias. The pulses are synchronized to atrial and ventricular events in such a fashion as to assure they occur outside of the vulnerable periods associated with both chambers. The device is provided with a pulse synchronizer which defines a first synchronization interval initiated following a sensed atrial event and a second synchronization interval initiated responsive to a sensed ventricular event and a pulse triggerer which triggers delivery of a cardioversion or defibrillation pulse responsive to the first and second synchronization intervals simultaneously being underway. In particular, the pulse triggerer may be responsive to initiation of the first synchronization interval during the second synchronization interval.

Abstract: In an implantable pacemaker.backslash.cardioverter.backslash.defibrillator, a system for correlating the delivery of an atrial cardioversion therapy to an optimum blood pressure to effect delivery of the therapy when the volume of the atrium is minimized. In a first embodiment, the blood pressure in the atrium or ventricle is monitored and delivery is timed to a low blood pressure occurring as blood is emptying from the atrium. In a variation ventricular pacing may be provided to ensure that the ventricles are contracting forcefully and at a rate which optimizes atrial emptying. In a second embodiment, the delivery of the cardioversion therapy is also timed to an optimum point or phase of the respiratory cycle. The optimum point or phase of the respiration cycle depends in part on the chamber to be cardioverted and the location of the cardioversion electrodes with respect to the chamber.

Abstract: A method of and apparatus for delivering ventricular pacing pulses to terminate high rate atrial tachyarrhythmias including fibrillation or flutter or to reduce the requirements for termination of atrial fibrillation or flutter. In response to detected atrial fibrillation or flutter, the apparatus delivers ventricular pacing pulses at a lower rate, for example one third or half of the preceding base pacing rate, for a defined, limited period of time. After delivery of the low rate ventricular pacing pulses for the defined time period, if the high rate atrial tachyarrhythmia is not terminated, an additional therapy such a high energy defibrillation pulse or pacing level pulse trains may be applied to the atria. Prior to the delivery of low rate ventricular pacing pulses, the apparatus may deliver a higher rate of ventricular pacing pulses, for example twice the preceding base pacing rate, so that the transition in rates occurring on delivery of the low rate pulses is made more pronounced.