Patent application number | Description | Published |
20080228093 | Systems and methods for enhancing cardiac signal features used in morphology discrimination - Methods and devices used to classify cardiac events based on morphological analysis of sensed signals are described. A signal comprising a cardiac signal component and a noise signal component is sensed. The sensed signal is processed to preferentially alter morphology of the cardiac signal component. The altered morphology of the cardiac signal component enhances detection of one or more features of the cardiac signal component. The features of the cardiac signal component are detected and the cardiac event is classified using the detected features. Processing the sensed signal may involve the use of adaptable signal processing parameters. For example, the signal processing parameters may be selected to accentuate one or more desirable features of the cardiac signal component or to mitigate one or more undesirable features of the cardiac signal component. | 09-18-2008 |
20080275522 | Non-captured intrinsic discrimination in cardiac pacing response classification - Cardiac devices and methods discriminate non-captured intrinsic beats during evoked response detection and classification by comparing the features of a post-pace cardiac signal with expected features associated with a non-captured response with intrinsic activation. Detection of a non-captured response with intrinsic activation may be based on the peak amplitude and timing of the cardiac signal. The methods may be used to discriminate between a fusion or capture beat and a non-captured intrinsic beat. Discriminating between possible cardiac responses to the pacing pulse may be useful, for example, during automatic capture verification and/or a capture threshold test. | 11-06-2008 |
20090069858 | Capture Detection for Multi-Chamber Pacing - Multi-chamber pacing may result in capture of one chamber, capture of multiple chambers, fusion, or non-capture. Approaches for detecting various capture conditions during multi-chamber pacing are described. Pacing pulses are delivered to left and right heart chambers during a cardiac cycle. A cardiac electrogram signal is sensed following the delivery of the pacing pulses. Left chamber capture only, right chamber capture only, and bi-chamber capture may be distinguished based on characteristics of the cardiac electrogram signal. Multi-chamber capture detection may be implemented using detection windows having dimensions of time and amplitude. The detection windows are associated with expected features, such as expected signal peaks, under a particular capture condition. The cardiac electrogram signal features are compared to detection windows to determine the capture condition. | 03-12-2009 |
20090105780 | Pacing Output Determination Based on Selected Capture Threshold Values - Approaches for adjusting the pacing energy delivered by a pacemaker are provided. Adjusting the pacing energy involves performing a plurality of capture threshold tests, each capture threshold test measuring a capture threshold of the heart. One or more measured captured thresholds are selected, including at least one capture threshold that is higher relative to other measured capture thresholds acquired by the plurality of capture threshold tests. The pacing energy is adjusted based on the one or more selected capture thresholds. | 04-23-2009 |
20100036449 | Adaptive Windowing for Cardiac Waveform Discrimination - Cardiac devices and methods provide adaptation of detection windows used to determine a cardiac response to pacing. Adapting a detection window involves sensing a cardiac signal indicative of a particular type of cardiac pacing response, and detecting a feature of the sensed cardiac signal. The cardiac response detection window associated with the type of cardiac pacing response is preferentially adjusted based on the location of the detected cardiac feature. Preferential adjustment of the detection window may involve determining a direction of change between the detection window and the detected feature. The detection window may be adapted more aggressively in a more preferred direction and less aggressively in a less preferred direction. | 02-11-2010 |
20100262207 | Methods and Systems for Managing Fusion and Noise in Cardiac Pacing Response Classification - Methods and systems for detecting noise in cardiac pacing response classification processes involve determining that a cardiac response classification is possibly erroneous if unexpected signal content is detected. The unexpected signal content may comprise signal peaks that have polarity opposite to the polarity of peaks used to determine the cardiac response to pacing. Fusion/noise management processes include pacing at a relatively high energy level until capture is detected after a fusion, indeterminate, or possibly erroneous pacing response classification is made. The relatively high energy pacing pulses may be delivered until capture is detected or until a predetermined number of paces are delivered. | 10-14-2010 |
20100286743 | Methods and Systems for Mitigating the Occurrence of Arrhythmia During Atrial Pacing - Noncaptured atrial paces can result in long-short cardiac cycles which are proarrhythmic for ventricular tachyarrhythmia. Approaches are described which are directed to avoiding proarrhythmic long-short cycles. For cardiac cycles in which the atrial pace captures the atrium, a first post ventricular refractory period (PVARP) and a first A-A interval are used. For cardiac cycles in which the atrial pace does not capture the atrium, both an extended PVARP and an extended A-A interval are used. The A-A interval following a noncaptured atrial pace is extended from an atrial depolarization sensed during the extended PVARP. | 11-11-2010 |
20110098773 | ESTIMATION OF DEDICATED BIPOLAR PACING VECTOR THRESHOLD - Methods and devices are described that allow estimation of an electrostimulation capture threshold, such as a dedicated bipolar pacing vector threshold. In an example, an equal-energy assumption between first and second pacing vectors can be used to estimate an electrostimulation capture threshold of a second pacing vector from a measured electrostimulation capture threshold of the first pacing vector and impedances of the first and second pacing vectors. In an example, a relationship between first and second pacing vectors can be determined from measured data, and a parameter of the relationship can be used with a measurement of an electrostimulation capture threshold of the first pacing vector to estimate an electrostimulation capture threshold of the second pacing vector. | 04-28-2011 |
20110098774 | ESTIMATION OF DEDICATED BIPOLAR PACING VECTOR THRESHOLD - Methods and devices are described that allow estimation of an electrostimulation capture threshold, such as a dedicated bipolar pacing vector threshold. In an example, an equal-energy assumption between first and second pacing vectors can be used to estimate an electrostimulation capture threshold of a second pacing vector from a measured electrostimulation capture threshold of the first pacing vector and impedances of the first and second pacing vectors. In an example, a relationship between first and second pacing vectors can be determined from measured data, and a parameter of the relationship can be used with a measurement of an electrostimulation capture threshold of the first pacing vector to estimate an electrostimulation capture threshold of the second pacing vector. | 04-28-2011 |
20110245890 | METHOD AND APPARATUS FOR PACING SAFETY MARGIN - An apparatus comprises a cardiac signal sensing circuit, a pacing therapy circuit, and a controller circuit. The controller circuit includes a safety margin calculation circuit. The controller circuit initiates delivery of pacing stimulation energy to the heart using a first energy level, changes the energy level by at least one of: a) increasing the energy from the first energy level until detecting that the pacing stimulation energy induces stable capture, or b) reducing the energy from the first energy level until detecting that the stimulation energy fails to induce capture, and continues changing the stimulation energy level until confirming stable capture or the failure of capture. The safety margin calculation circuit calculates a safety margin of pacing stimulation energy using at least one of a determined stability of a parameter associated with evoked response and a determined range of energy levels corresponding to stable capture or intermittent failure of capture. | 10-06-2011 |
20110313488 | AUTOMATIC NEURAL STIMULATION TITRATION SWEEP - Various neural stimulator embodiments comprise controller circuitry, neural stimulation output circuitry, sensor circuitry and a memory. The neural stimulation output circuitry is configured to deliver the neural stimulation. The controller circuitry is configured to control stimulation parameters of the neural stimulation delivered by the neural stimulation output circuitry. The sensor circuitry, including at least one sensor, is configured to sense a response to the neural stimulation. The controller is configured to communicate with the sensor circuitry. The memory has instructions stored therein, operable on by the controller circuitry. The instructions include instructions for delivering neural stimulation using the neural stimulation output circuitry, instructions for controlling a titration sweep wherein the titration sweep varies stimulation parameter values, and instructions for monitoring a response to the titration sweep and automatically selecting stimulation parameters that provide an efficacious neural stimulation and provide a desirable safety margin to prevent injury to neural tissue. | 12-22-2011 |
20120165895 | Non-Captured Intrinsic Discrimination in Cardiac Pacing Response Classification - Cardiac devices and methods discriminate non-captured intrinsic beats during evoked response detection and classification by comparing the features of a post-pace cardiac signal with expected features associated with a non-captured response with intrinsic activation. Detection of a non-captured response with intrinsic activation may be based on the peak amplitude and timing of the cardiac signal. The methods may be used to discriminate between a fusion or capture beat and a non-captured intrinsic beat. Discriminating between possible cardiac responses to the pacing pulse may be useful, for example, during automatic capture verification and/or a capture threshold test. | 06-28-2012 |
20130013020 | Methods and Systems for Managing Fusion and Noise in Cardiac Pacing Response Classification - Methods and systems for detecting noise in cardiac pacing response classification processes involve determining that a cardiac response classification is possibly erroneous if unexpected signal content is detected. The unexpected signal content may comprise signal peaks that have polarity opposite to the polarity of peaks used to determine the cardiac response to pacing. Fusion/noise management processes include pacing at a relatively high energy level until capture is detected after a fusion, indeterminate, or possibly erroneous pacing response classification is made. The relatively high energy pacing pulses may be delivered until capture is detected or until a predetermined number of paces are delivered. | 01-10-2013 |
20130245466 | WITHIN-PATIENT ALGORITHM TO PREDICT HEART FAILURE DECOMPENSATION - This document discusses, among other things, systems and methods for predicting heart failure decompensation using within-patient diagnostics. A method comprises detecting an alert status of each of one or more sensors; calculating an alert score by combining the detected alerts; and calculating a composite alert score, the composite alert score being indicative of a physiological condition and comprising a combination of two or more alert scores. | 09-19-2013 |
20140018875 | METHOD AND APPARATUS FOR PACING SAFETY MARGIN - An apparatus comprises a cardiac signal sensing circuit, a pacing therapy circuit, and a controller circuit. The controller circuit includes a safety margin calculation circuit. The controller circuit initiates delivery of pacing stimulation energy to the heart using a first energy level, changes the energy level by at least one of: a) increasing the energy from the first energy level until detecting that the pacing stimulation energy induces stable capture, or b) reducing the energy from the first energy level until detecting that the stimulation energy fails to induce capture, and continues changing the stimulation energy level until confirming stable capture or the failure of capture. The safety margin calculation circuit calculates a safety margin of pacing stimulation energy using at least one of a determined stability of a parameter associated with evoked response and a determined range of energy levels corresponding to stable capture or intermittent failure of capture. | 01-16-2014 |