Abstract: Implementations of various technologies described herein are directed toward a sensing architecture for use in cardiac rhythm management devices. The sensing architecture may provide a method and means for certifying detected events by the cardiac rhythm management device. Moreover, by exploiting the enhanced capability to accurately identifying only those sensed events that are desirable, and preventing the use of events marked as suspect, the sensing architecture can better discriminate between rhythms appropriate for device therapy and those that are not.

Abstract: Template formation methods for use in implantable cardiac rhythm management devices. In an illustrative method, a signal is captured in an implanted cardiac rhythm management device, and parameters for analysis of the captured signal are then defined. Then, in the example, additional signals can be captured and used to either verify or discard the captured signal defined parameters. The template formation methods provide for creating a robust template to compare with sensed cardiac complexes. Devices and systems configured to perform template formation and verification methods are also shown.

Abstract: A cardiac rhythm management system includes a time-dependent frequency response for sensed heart signals. A change in the frequency response of a sensing circuit is triggered by a sensed or evoked event to make it less sensitive to the detection of a subsequent event for a period of time. For example, a passband bandwidth is reduced, then increased during the time period triggered by the event. For even more event-triggered selectivity, a gain is reduced, then increased during the time period triggered by the event. This provides better discrimination between particular events included in a heart signal so that appropriate therapy can be delivered to the patient based such events.

Abstract: The implantable cardiac treatment system of the present invention is capable of choosing the most appropriate electrode vector to sense within a particular patient. In certain embodiments, the implantable cardiac treatment system determines the most appropriate electrode vector for continuous sensing based on which electrode vector results in the greatest signal amplitude, or some other useful metric such as signal-to-noise ratio (SNR). The electrode vector possessing the highest quality as measured using the metric is then set as the default electrode vector for sensing. Additionally, in certain embodiments of the present invention, a next alternative electrode vector is selected based on being generally orthogonal to the default electrode vector. In yet other embodiments of the present invention, the next alternative electrode vector is selected based on possessing the next highest quality metric after the default electrode vector.

Abstract: Methods and implantable devices for cardiac signal analysis. The methods and devices make use of waveform appraisal techniques to distinguish event detections into categories for suspect events and waveform appraisal passing events. When adjustments are made to the data entering analysis for waveform appraisal, the waveform appraisal thresholds applied are modified as well. For example, when the data analysis window for waveform appraisal changes in length, a waveform appraisal threshold is modified. Other changes, including changes in sensing characteristics with which waveform appraisal operates may also result in changes to the waveform appraisal threshold including changes in gain, sensing vector, activation of other devices, implantee posture and other examples which are explained.

Abstract: Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In illustrative examples, sensed data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data.

Abstract: Methods and devices for adjusting therapy delivery decisions in an implantable cardiac stimulus device by observing cardiac activity following an initial identification of a treatable condition. In some examples, cardiac activity that appears benign is quantified and a therapy confirmation threshold is adjusted according to how much apparently benign cardiac activity is seen after an initial identification of a treatable condition. In other examples, a new threshold is applied following the initial identification of treatable condition, removing historical data preceding the initial identification from subsequent therapy delivery decisions.

Abstract: A method for operating a cardiac rhythm management device in which a clinical state vector is computed as a combination of a plurality of parameters related to a patient's heart failure status and compared to a previously computed clinical state vector to determine a clinical trajectory indicative of changes in the patient's heart failure status. Such detected changes in status can be used both as a clinical tool to evaluate treatment and to automatically adjust the operation of the device.

Abstract: Methods and implantable devices that address response to, or avoidance of, likely non-cardiac voltages including afterpotentials from external or internal stimulus. Some examples are directed toward methods of operation in implantable medical devices, the methods configured for identifying saturation of input circuitry and mitigating the effects of such saturation. Some examples are directed toward implantable cardiac stimulus or monitoring devices that include methods for identifying saturated conditions and mitigating the effects of such saturation.

Abstract: Methods and implantable cardiac stimulus devices that include leads designed to avoid post-shock afterpotentials. Some examples are directed toward lead-electrode designs that reduce the impact of an applied stimulus on sensing attributes.

Abstract: Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In illustrative examples, captured data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data. New methods for organizing the use of morphology and rate analysis in an overall architecture for rhythm classification and cardiac signal analysis are also discussed.

Abstract: The implantable cardiac treatment system of the present invention is capable of choosing the most appropriate electrode vector to sense within a particular patient. In certain embodiments, the implantable cardiac treatment system determines the most appropriate electrode vector for continuous sensing based on which electrode vector results in the greatest signal amplitude, or some other useful metric such as signal-to-noise ratio (SNR). The electrode vector possessing the highest quality as measured using the metric is then set as the default electrode vector for sensing. Additionally, in certain embodiments of the present invention, a next alternative electrode vector is selected based on being generally orthogonal to the default electrode vector. In yet other embodiments of the present invention, the next alternative electrode vector is selected based on possessing the next highest quality metric after the default electrode vector.

Abstract: Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In some examples, captured data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data. Several examples emphasize the use of morphology analysis using correlation to static templates and/or inter-event correlation analysis.

Abstract: The implantable cardiac treatment system of the present invention is capable of choosing the most appropriate electrode vector to sense within a particular patient. In certain embodiments, the implantable cardiac treatment system determines the most appropriate electrode vector for continuous sensing based on which electrode vector results in the greatest signal amplitude, or some other useful metric such as signal-to-noise ratio (SNR). The electrode vector possessing the highest quality as measured using the metric is then set as the default electrode vector for sensing. Additionally, in certain embodiments of the present invention, a next alternative electrode vector is selected based on being generally orthogonal to the default electrode vector. In yet other embodiments of the present invention, the next alternative electrode vector is selected based on possessing the next highest quality metric after the default electrode vector.

Abstract: Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In illustrative examples, captured data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data. New methods for organizing the use of morphology and rate analysis in an overall architecture for rhythm classification and cardiac signal analysis are also discussed.

Abstract: Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In some illustrative examples, detected events are analyzed to identify changes in detected event amplitudes. When detected event amplitudes are dissimilar from one another, a first set of detection parameters may be invoked, and, when detected event amplitudes are similar to one another, a second set of detection parameters may be invoked. Additional methods determine whether the calculated heart rate is “high” or “low,” and then may select a third set of detection parameters for use when the calculated heart rate is high.

Abstract: Methods and devices that are configured to deliver cardiac stimuli in a particular fashion. In an illustrative embodiment, a method is used wherein a first stimulus is delivered using a first polarity, and, if the first stimulus fails to successfully convert an arrhythmia, a second stimulus having a second polarity that is different from or opposite of the first polarity is then delivered. Subsequent stimuli, if needed, are delivered in a continuing alternating-polarity manner. The first polarity may be determined by observing whether successfully-converting stimulus has been delivered previously and, if so, the polarity of the most recent stimulus that resulted in successful conversion is used as the first polarity. In additional embodiments, electrode configuration may be changed instead of or in addition to polarity, following unsuccessful stimulus delivery. Devices configured to perform such methods are included in additional illustrative embodiments.

Abstract: Adaptive methods for initiating charging of the high power capacitors of an implantable medical device for therapy delivery after the patient experiences a non-sustained arrhythmia. The adaptive methods adjust persistence criteria used to analyze an arrhythmia prior to initiating a charging sequence to deliver therapy.

Abstract: Methods of using a template having a template data set and template parameters to provide improved alignment of captured cardiac signal data to a stored template. More particularly, in an illustrative method, a captured cardiac signal is first configured using template parameters for a stored template. Then, once configured, the captured cardiac signal is then compared to the stored template. Other embodiments include implantable cardiac treatment devices including operational circuitry configured to perform the illustrative method. In a further embodiment, more than one stored templates may be used. Each template can have independently constructed parameters, such that a single captured cardiac signal may be configured using first parameters for comparison to a first template, and using second parameters for comparison to a second template.

Abstract: The present invention is directed toward a detection architecture for use in implantable cardiac rhythm devices. The detection architecture of the present invention provides methods and devices for discriminating between arrhythmias. Moreover, by exploiting the enhanced specificity in the origin of the identified arrhythmia, the detection architecture can better discriminate between rhythms appropriate for device therapy and those that are not.