摘要:
A method and apparatus for detection of changes in physiologic parameters of a patient that includes generating measured physiologic parameters, generating an adaptive baseline trend of the measured physiologic parameters corresponding to a first time period, generating a short term trend of the measured physiologic parameters corresponding to a second time period less than the first time period, and generating a metric of physiologic parameter change between the adaptive baseline trend and one of a most recent measured physiologic parameter and the short term trend of the measured physiologic parameters.
摘要:
A method and apparatus for determining oversensing in a medical device that includes sensing cardiac signals, determining an oversensing characteristic associated with cardiac signals sensed during a predetermined sensing window, identifying oversensing in response to the oversensing characteristic, determining, in response to oversensing being identified, an adjusting characteristic associated with cardiac signals sensed during the predetermined sensing window, and updating a sensing parameter in response to the determined adjusting characteristic.
摘要:
The invention provides methods and apparatus for determining in a non-tracking pacing mode (e.g., DDI/R, VVI/R) whether a ventricular pacing stimulus is capturing a paced ventricle, including some or all of the following aspects. For example, increasing a ventricular pacing rate a nominal amount to an overdrive pacing rate higher than a most recent heart rate and evaluating a conduction interval from a first pacing ventricle to a second sensing ventricle and then continuing to monitor the underlying rate to ensure that a threshold testing pacing rate will not exceed a predetermined minimum interval and providing pacing stimulation to the first ventricle and sensing the second ventricle to determine whether the pacing stimulation to the first ventricle was one of sub-threshold and supra-threshold. The methods and apparatus are especially useful in conjunction with ensuring actual delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”).
摘要:
Techniques for storing electrograms (EGMS) that are associated with sensed episodes or events that may be non-physiological and, instead, associated with a sensing integrity condition are described. In some examples, a device or system identifies suspected non-physiological NSTs, and stores an EGM for the suspected non-physiological NSTs within an episode log. In some examples, a device or system determines whether to store an EGM for a suspected non-physiological episode or event based on whether an impedance integrity criterion has been satisfied. For example, a device or system may store an EGM for a detected short interval if the impedance integrity criterion has been met. In some examples, a device or system determines whether to buffer EGM data based on whether an impedance integrity criterion or other sensing integrity criterion has been met.
摘要:
The present invention provides a technique for verifying pacing capture of a ventricular chamber, particularly to ensure desired delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”). The invention also provides for ventricular capture management by delivering a single ventricular pacing stimulus and checking inter-ventricular conduction during a temporal window to determine if the ventricular pacing stimulus captured the chamber. If a loss-of-capture (LOC) signal results from the capture management testing, then the characteristics of the applied pacing pulses are modified and the conduction test repeated. In the event that the LOC signal persists, a pacing mode-switch to an atrial-based pacing therapy and/or non-bi-ventricular pacing regimen can be implemented.
摘要:
A method and apparatus for adjusting a sensing parameter in a medical device that includes a sensing electrode sensing cardiac signals, a processor to determine an adjusting characteristic associated with the cardiac signals sensed over a predetermined sensing window, and a control unit to update the sensing parameter in response to the determined adjusting characteristic.
摘要:
A method and apparatus of updating a sensing parameter in a medical device that includes sensing cardiac signals, determining intervals in response to the sensed cardiac signals, determining interval patterns associated with the determined intervals, and updating the sensing parameter in response to the determined interval patterns.
摘要:
A pacing system for selectively sensing spontaneous ventricular cardiac depolarizations at first and second spaced apart ventricular sites during the time-out of an AV delay and delivering pace pulses to the spaced apart ventricular sites in a triggered pacing mode. The first and second ventricular sites are preferably right ventricular (RV) and left ventricular (LV) pace/sense electrode sites, and RV event and LV event signals are sensed at the RV and LV pace/sense electrodes. A V-A pacing escape interval and a ventricular refractory period, a trigger pace window, an upper rate interval and further post-event time periods are started upon a RV or LV sense event or a first ventricular pace pulse delivered upon time-out of the AV delay. A triggered ventricular pace pulse or pulses is delivered to one or both of the RV and LV pace/sense electrode sites upon detecting an RV sense event or LV sense event during the AV delay. In one triggered pacing mode, a RV or LV pace pulse is delivered upon a RV or LV sense event during the AV delay to one of the RV or LV pace/sense electrode sites. In another triggered pacing mode, a triggered pace pulse is delivered to the other one of the RV or LV pace/sense electrode sites after a triggered pacing delay timed from a non-refractory RV or LV sense event occurring during the AV delay. In still another triggered pacing mode, a first pace pulse is delivered upon a RV or LV sense event, the triggered pacing delay is timed out, and a second pace pulse is delivered to the other one of the RV or LV pace/sense electrode sites after time-out of the triggered pacing delay. Triggered ventricular pacing is disabled during the V-A escape interval. Such a system could be employed in pacemakers that are part of a cardio defibrillator system if desired.
摘要:
Multi-site cardiac pacing systems for providing pacing to multiple spaced apart sites of a patient's heart, including especially but not limited to sites in right heart chamber (RHC) and left heart chamber (LHC), in triggered pacing modes while avoiding inappropriate delivery of triggered pacing to the RHC and/or LHC on a non-refractory sense event that occurs early in the cardiac cycle.
摘要:
The present disclosure is directed to generating and displaying an electrogram (EGM) summary for use by physicians or other clinicians. An implantable medical device (IMD) transmits EGM signal data for a number of cardiac episodes to an external computing device. The external computing device selects a subset of the cardiac episodes for which information or images are displayed to the user. In various examples, cardiac episodes may be selected for display based at least in part on a retrospective analysis classification of the cardiac episode.