Patent application number | Description | Published |
20080269624 | MORPHOLOGY BASED ARRHYTHMIA DETECTION - A medical device system and associated method sample an EGM signal over a processing window having a predetermined time duration. A number of morphology metrics are determined from the sampled EGM signal, and a heart rhythm is detected in response to the morphology metrics without determining depolarization intervals. The morphology metrics include metrics determined from a slope signal derived from the EGM signal in one embodiment. | 10-30-2008 |
20090093860 | AUTOMATIC DETERMINATION OF T-SHOCK VULNERABLE WINDOW - A method and apparatus for determining a T-wave shock interval sense a cardiac electrogram (EGM) signal comprising a T-wave signal. A T-wave center is determined from the EGM signal, and a T-wave shock interval is determined in response to determining the T-wave center. A T-wave shock is delivered at the T-wave shock interval computed based on the T-wave center. | 04-09-2009 |
20090192398 | METHOD AND APPARATUS FOR MONITORING T-WAVE ALTERNANS - An implantable medical device and associated method assess T-wave alternans by sensing a cardiac electrogram (EGM) signal and selecting a pair of consecutive T-wave signals from the EGM signal. A first amplitude and a second amplitude from each of the consecutive T-wave signals are determined. The differences between the first amplitudes and the second amplitudes of the consecutive T-wave signal pairs are used to compute a T-wave alternans metric. | 07-30-2009 |
20090204194 | MEDICAL SYSTEM INCLUDING A NOVEL BIPOLAR PACING PAIR - A medical system includes a first low voltage electrode adapted for intimate contact with tissue at an implant site, in order to provide pacing stimulation in conjunction with a second low voltage electrode. A porous layer is formed over the second electrode; the porous layer allows conduction therethrough while preventing contact between the second electrode and tissue in proximity to the implant site. | 08-13-2009 |
20100023072 | Methods for the Determination of T-Shock Vulnerable Window from Far-Field Electrograms in Implantable Cardioverter Defibrillators - Methods for determination of timing for electrical shocks to the heart to determine shock strength necessary to defibrillate a fibrillating heart. The timing corresponds the window of most vulnerability in the heart, which occurs during the T-wave of a heartbeat. Using a derivatized T-wave representation, the timing of most vulnerability is determined by a center of the area method, peak amplitude method, width method, or other similar methods. Devices are similarly disclosed embodying the methods of the present disclosure. | 01-28-2010 |
20100152804 | SECURE AND EFFICACIOUS THERAPY DELIVERY FOR A PACING ENGINE - The above-described methods and apparatus are believed to be of particular benefit for patients suffering heart failure including cardiac dysfunction, chronic HF, and the like and all variants as described herein and including those known to those of skill in the art to which the invention is directed. It will understood that the present invention offers the possibility of monitoring and therapy of a wide variety of acute and chronic cardiac dysfunctions. The current invention provides systems and methods for delivering therapy for cardiac hemodynamic dysfunction via the innervated myocardial substrate receives one or more discrete pulses of electrical stimulation during the refractory period of said innervated myocardial substrate. | 06-17-2010 |
20100185109 | "BLURRED TEMPLATE" APPROACH FOR ARRHYTHMIA DETECTION - An implantable medical device and associated method sense cardiac signals for deriving a template representing a known EGM waveform morphology and for classifying an unknown waveform morphology. A boundary of the template, offset from the template, is computed and compared to an unknown waveform morphology for classifying the unknown waveform morphology. | 07-22-2010 |
20100191301 | HYBRID SINGLE-CHAMBER TO SIMULTANEOUS PACING METHOD FOR DISCRIMINATION OF TACHYCARDIAS - A cardiac medical device and associated method control delivery of anti-tachycardia pacing (ATP) in response to detecting tachycardia. In one embodiment, an initial set of single chamber pacing pulses are delivered in a single one of the atrium and the ventricle, the other one of the atrium and the ventricle being a non-paced chamber during the initial set of single chamber pacing pulses. The device detects simultaneity between a sensed event in the non-paced chamber and one of the single chamber pacing pulses and delivers ATP in both the atrium and the ventricle in response to detecting the simultaneity. | 07-29-2010 |
20100241180 | COMBINED HEMODYNAMIC AND EGM-BASED ARRHYTHMIA DETECTION - A medical device and associated method for detecting arrhythmias that includes electrodes for sensing cardiac electrical signals and a hemodynamic sensor for sensing a hemodynamic signal. An episode of cardiac electrical event intervals meeting cardiac arrhythmia detection criteria is detected from the sensed electrical signals. Cardiac mechanical events and/or cardiac mechanical event intervals are measured from the hemodynamic signal and used to withhold or confirm a cardiac arrhythmia detection of the episode. | 09-23-2010 |
20100241182 | COMBINED HEMODYNAMIC AND EGM-BASED ARRHYTHMIA DETECTION - A medical device and associated method for detecting arrhythmias that includes sensing cardiac electrical signals and cardiac hemodynamic signals, determining a long-term baseline hemodynamic measurement in response to a plurality of the sensed cardiac hemodynaic signals, detecting a period of increased metabolic demand in response to the sensed cardiac electrical signals, determining a sinus tachycardia baseline hemodynamic measurement in response sensing of cardiac hemododynamic signals during the detected period of increased metabolic demand, and detecting the arrhythmia and delivering therapy in response to one of only the sensed cardiac electrical signals and the sensed cardiac electrical signals in combination with one or both of the determined long-term baseline hemodynamic measurement and the sinus tachycardia baseline hemodynamic measurement | 09-23-2010 |
20100249627 | Detecting A Condition Of A Patient Using A Probability-Correlation Based Model - Techniques are described for detecting a condition of a patient using a probability-correlation based model that integrates a plurality of parameters associated with the condition. A medical device that operates in accordance with the techniques obtains a plurality of parameters associated with the condition of the patient. The medical device obtains probabilities that the condition of the patient exists based on each single parameter separately and correlations between each of the parameters and the other ones of the parameters. After obtaining the probabilities and correlations associated with each of the parameters, the medical device determines whether the condition of the patient exists based on the determined probabilities and correlations. Such techniques may be particularly effective for use in distinguishing whether a rhythm of a patient is treatable, e.g., VT or VF, or non-treatable, e.g., SVT. | 09-30-2010 |
20100274148 | DISTINGUISHING BETWEEN TREATABLE AND NON-TREATABLE HEART RHYTHMS - Techniques are described for distinguishing between treatable and non-treatable heart rhythms. A medical device that operates in accordance with the techniques analyzes characteristics over several cardiac event intervals to detect initiation of a sudden rate onset. After detection of the initiation of the sudden rate onset, the IMD analyzes a morphology of an EGM associated with a selected cardiac event within the first several beats after the initiation of sudden rate onset. In one example, the IMD analyzes the morphology of the EGM associated with the first cardiac event immediately subsequent to the initiation of the sudden rate onset. If the morphology of the EGM of the selected cardiac event is abnormal compared to template EGM, the rhythm is classified as treatable. Otherwise, the rhythm is classified as non-treatable. | 10-28-2010 |
20100331903 | HEART SOUND SENSING TO REDUCE INAPPROPRIATE TACHYARRHYTHMIA THERAPY - Techniques for detecting heart sounds to reduce inappropriate tachyarrhythmia therapy are described. In some examples, a medical device determines that a cardiac rhythm of the patient is treatable with a therapy, such as a defibrillation pulse, based on a cardiac electrogram (EGM). The medical device analyzes detected heart sounds, and withholds or allows the therapy based on the analysis of the heart sounds. | 12-30-2010 |
20110022104 | METHODS AND APPARATUS FOR DETECTING VENTRICULAR DEPOLARIZATIONS DURING ATRIAL PACING - AV synchronous, dual chamber pacing systems are disclosed having improved sensing of ectopic ventricular depolarizations or PVCs coincidentally occurring at or shortly following delivery of an A-PACE pulse. A first ventricular sense amplifier that is blanked during and following delivery of an A-PACE pulse is coupled to active and indifferent ventricular pace/sense electrodes defining a ventricular sense vector for sensing natural ventricular depolarizations and declaring a V-EVENT. A far field PVC sense amplifier coupled to a far field PVC sense electrode pair defining a PVC sense vector detects such PVCs while the ventricular sense amplifier is blanked. A PVC declared during the ventricular blanking period by the far field PVC sense amplifier is employed to deliver a VSP pulse upon time-out of a VSP delay, if the VSP function is provided and programmed ON, and/or to halt time-out of an AV delay. | 01-27-2011 |
20110077704 | PACE DISCRIMINATION OF TACHYCARDIA USING ATRIAL-VENTRICULAR PACING - A cardiac medical device and associated method control delivery of dual chamber burst pacing pulses in response to detecting tachycardia. A number of cardiac cycles occurring in a first cardiac chamber are identified subsequent to the dual chamber pacing pulses. The number of sensed intrinsic events occurring in a second cardiac chamber during the first chamber cardiac cycles is determined as a number of second chamber events. The tachycardia episode is classified in response to the number of second chamber events. | 03-31-2011 |
20110077705 | PACE DISCRIMINATION OF TACHYCARDIA USING ATRIAL-VENTRICULAR PACING - A cardiac medical device and associated method control delivery of dual chamber burst pacing pulses in response to detecting tachycardia. In one embodiment, a single chamber pacing pulse is delivered in response to detecting a tachycardia. Dual chamber pacing pulses are delivered subsequent to the single chamber pacing pulse. An intrinsic depolarization is sensed subsequent to delivering the dual chamber pacing pulses. The tachycardia episode is classified in response to the sensed intrinsic depolarization. | 03-31-2011 |
20110196247 | REJECTING OVERSENSING DUE TO NOISE - In general, this disclosure is directed to signal processing based methods to reject oversensing due to electromagnetic interference or other noise without compromising tachyarrhythmia detection sensitivity. A method comprises sensing a signal indicative of cardiac activity, detecting a cardiac event based on the signal, determining a count of fluctuations of the signal within a window between the detected cardiac event and a next cardiac event, and determining whether noise is present in the signal based on the count. | 08-11-2011 |
20110270102 | METHOD AND APPARATUS FOR DETECTING AND DISCRIMINATING TACHYCARDIA - A medical device and associated method for discriminating cardiac events includes sensing a cardiac signal spatially located across approximately a full duration of a predetermined sensing window. A match score is determined corresponding to the sensed cardiac signal. A beat feature of multiple beat features across less than the full duration of the sensing window is determined, the beat feature being selected from the multiple beat features in response to the match score. Cardiac event evidence is accumulated in response to the match score and the determined beat feature, and cardiac events are discriminated in response to the accumulated cardiac evidence. | 11-03-2011 |
20110270103 | METHOD AND APPARATUS FOR DETECTING AND DISCRIMINATING TACHYCARDIA - A medical device and associated method for discriminating cardiac events includes determining whether a first match score is within a first match zone having a first correlation with a non-treatable cardiac event, a second match zone having a second correlation with the non-treatable cardiac event less than the first correlation with the non-treatable event, a third match zone having a first correlation with a treatable cardiac event, and a fourth match zone having a second correlation with the treatable cardiac event greater than the first correlation with the treatable cardiac event. A determination is made as to whether a second match score and a third match score are within the first match zone, the second match zone, the third match zone and the fourth match zone to generate a first adjusting factor, and cardiac event evidence is accumulated in response to the first adjusting factor for discriminating cardiac events. | 11-03-2011 |
20110270106 | METHOD AND APPARATUS FOR DETECTING AND DISCRIMINATING TACHYCARDIA - A medical device and associated method for discriminating cardiac events sense cardiac signals that includes determining whether a first match score is within one of a first match zone corresponding to a first cardiac event, and a second match zone corresponding to the first cardiac event, and determining whether a second match score is within one of the first match zone, the second match zone, and a third match zone corresponding to a second cardiac event different from the first cardiac event. One of increasing and decreasing an event counter is performed in response to both the determination of whether the first match score is within one of the first match zone and the second match zone and the determination of whether the second match score is within one of the first match zone, the second match zone, and the third match zone. | 11-03-2011 |
20110270107 | METHOD AND APPARATUS FOR DETECTING AND DISCRIMINATING TACHYCARDIA - A medical device and associated method for discriminating cardiac events includes determining whether a first match score is within a first match zone having a first correlation with a non-treatable cardiac event, a second match zone having a second correlation with the non-treatable cardiac event less than the first correlation, a third match zone having a first correlation with a treatable cardiac event, and a fourth match zone having a second correlation with the treatable cardiac event greater than the first correlation with the treatable cardiac event. In response to the first match score being within one of the first and second match zones, a determination is made whether consecutive match scores are within the first match zone and whether a break in the treatable cardiac event has occurred. Cardiac evidence is accumulated in response to determining whether a break has occurred and utilized to discriminate cardiac events. | 11-03-2011 |
20110270108 | METHOD AND APPARATUS FOR DETECTING AND DISCRIMINATING TACHYCARDIA - A medical device and associated method for monitoring a patient's heart rhythm sense cardiac events and detect a sudden change in the heart rhythm in response to the sensed cardiac events. Detecting the sudden change includes determining a variability of intervals between the sensed cardiac events and switching between a low variability mode of operation and a high variability mode of operation in response to the variability of intervals. During the low variability mode, detecting the sudden change includes detecting an increase in the rate of cardiac events. During the high variability mode, detecting the sudden change includes detecting a sudden decrease in the variability of the cardiac event intervals. A concerning cardiac rhythm is detected in response to detecting the sudden change. | 11-03-2011 |
20120004515 | MULTI-CHANNEL SENSING METHODS IN IMPLANTABLE CARDIOVERTOR DEFIBRILLATORS - An implantable medical device uses an implantable sensor for acquiring a physiological signal that is received by a digital signal processor. The digital signal processor is a multi-channel signal processor including a first signal processing channel having a first sensitivity for sensing the physiological signal and a second signal processing channel having a second sensitivity different than the first sensitivity for sensing the physiological signal. | 01-05-2012 |
20120095520 | SEQUENTIAL DISCRIMINATION APPROACH FOR DETECTING TREATABLE CARDIAC RHYTHMS - A system and method for use in a medical device for discriminating cardiac events establishes population-based thresholds corresponding to cardiac signal morphology metrics for discriminating between a first cardiac event and a second cardiac event. A population-based threshold criterion for discriminating cardiac events is established. The population-based threshold criterion is applied to a cardiac signal segment and the segment is classified if the criterion is satisfied. A patient-specific threshold is established in response to the sensed cardiac signal segment not being classified after applying the population-based threshold criterion. The sensed signal segment is classified in response to the patient-specific threshold comparison. | 04-19-2012 |
20120101393 | SYSTEM AND METHOD FOR DERIVING RESPIRATION FROM INTRACARDIAC ELECTROGRAMS (EGM) OR ECG SIGNALS - A method and apparatus for monitoring respiration in a patient sense a cardiac electrical signal and detect signal peaks from the cardiac electrical signal. A peak amplitude waveform is generated from the signal peaks. a first derivative of the peak amplitude waveform is computed. Inspiration pulses are derived from the first derivative signal, and a respiration metric can be computed using the inspiration pulses derived from the cardiac electrical signal. | 04-26-2012 |
20120165810 | IMPLANTED DEVICE DATA TO GUIDE ABLATION THERAPY - A medical device system and associated method for guiding ablation therapy sense cardiac signals using implantable electrodes and detect spontaneous cardiac events from the sensed cardiac signals. Pacing pulses are delivered in response to detecting a spontaneous cardiac event and a return cycle length is measured. The spontaneous cardiac event is clustered with a previously detected cardiac event in response to the measured return cycle length. Data corresponding to the clustered cardiac events is displayed to guide an ablation therapy. | 06-28-2012 |
20120165811 | IMPLANTED DEVICE DATA TO GUIDE ABLATION THERAPY - A medical device system and associated method for guiding ablation therapy sense cardiac signals using implantable electrodes and detect spontaneous cardiac events from the sensed cardiac signals. Pacing pulses are delivered and a return cycle length is measured in response to the plurality of pacing pulses. The spontaneous cardiac event is clustered with a previously detected cardiac event in response to the measured return cycle length, and a targeted ablation site is estimated in response to the measured return cycle length. A transit time interval, corresponding to a distance traversed by a depolarization associated with a last one of the plurality of pacing pulses when a reset condition occurs, is computed using the return cycle length, and the ablation site is estimated in response to the computed transit time interval. | 06-28-2012 |
20120232605 | USING FOCAL MYOCARDIAL STIMULATION TO DISTINGUISH SUPRAVENTRICULAR TACHYCARDIA FROM VENTRICULAR TACHYCARDIA - An apparatus and method to discriminate cardiac events by sensing atrial and ventricular depolarizations having associated refractory periods thereafter. A fast ventricular rate is detected in response to the sensed ventricular depolarizations. Responsive to detecting the fast ventricular rate, at least one stimulus pulse is delivered to atrial tissue within the associated refractory period of the ventricle but outside of an associated refractory period of the stimulated atrial tissue. A ventricular response to the atrial tissue stimulus pulse is determined, and the cardiac event is discriminated based on the ventricular response to the atrial tissue stimulus pulse. | 09-13-2012 |
20120232606 | USING FOCAL MYOCARDIAL STIMULATION TO DISTINGUISH SUPRAVENTRICULAR TACHYCARDIA FROM VENTRICULAR TACHYCARDIA - An apparatus and method to discriminate cardiac events by sensing atrial and ventricular depolarizations having associated refractory periods thereafter. A fast ventricular rate is detected in response to the sensed ventricular depolarizations. Responsive to detecting the fast ventricular rate, at least one stimulus pulse is delivered to atrial tissue within the associated refractory period of the ventricle but outside of an associated refractory period of the stimulated atrial tissue. A ventricular response to the atrial tissue stimulus pulse is determined, and the cardiac event is discriminated based on the ventricular response to the atrial tissue stimulus pulse. | 09-13-2012 |
20120283587 | ASSESSING INTRA-CARDIAC ACTIVATION PATTERNS AND ELECTRICAL DYSSYNCHRONY - Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient. | 11-08-2012 |
20120284003 | ASSESSING INTRA-CARDIAC ACTIVATION PATTERNS - Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient. | 11-08-2012 |
20120289845 | TECHNIQUES FOR DETERMINING MORPHOLOGICAL STABILITY OF CARDIAC CYCLES - A method includes retrieving electrogram (EGM) data for N cardiac cycles from a memory of an implantable medical device. N is an integer greater than 1. The method further include categorizing each of the N cardiac cycles into one of a plurality of categories based on a morphology of the N cardiac cycles and performing comparisons between pairs of the N cardiac cycles. Each of the comparisons between two cardiac cycles includes detecting a mismatch between the two cardiac cycles when the two cardiac cycles are in different categories, and detecting a match between the two cardiac cycles when the two cardiac cycles are in the same category. Additionally, the method includes classifying the rhythm of the N cardiac cycles based on a number of detected matches and detected mismatches. | 11-15-2012 |
20120289846 | TECHNIQUES FOR DETERMINING CARDIAC CYCLE MORPHOLOGY - A method includes storing an electrogram (EGM) template in a memory. The EGM template includes first and second alignment points at first and second peaks of the EGM template, respectively. The method further includes identifying first and second peaks of a cardiac cycle EGM acquired by a medical device and selecting one of the first and second peaks of the cardiac cycle EGM to align with one of the first and second alignment points based on an order in which the first and second peaks of the cardiac cycle EGM occur. Additionally, the method includes aligning the selected one of the first and second peaks with one of the first and second alignment points and determining an amount of similarity between the cardiac cycle EGM and the EGM template after alignment. | 11-15-2012 |
20120296387 | PHRENIC NERVE STIMULATION DETECTION USING HEART SOUNDS - A method of delivering phrenic nerve stimulation in a medical device system that includes detecting an activation event, delivering phrenic nerve stimulation therapy in response to the detected activation event, sensing a heart sound signal, in response to the delivered phrenic nerve stimulation therapy, monitoring a portion of the sensed heart sound signal, the portion defined by a predetermined window ocurring after the delivered phrenic nerve stimulation therapy, and determining whether the delivered phrenic nerve stimulation therapy was successful in response to the monitoring. | 11-22-2012 |
20120296388 | PHRENIC NERVE STIMULATION DETECTION USING HEART SOUNDS - A method and system of detecting phrenic nerve stimulation in a patient that includes detecting an activation event, obtaining a heart sound signal of a patient from an implanted heart sound sensor, determining that an electrical stimulation has been applied to the patient, in response to detecting the activation event, monitoring a portion of the heart sound signal, the portion defined by a predetermined window after the application of the electrical stimulation, and determining whether phrenic nerve stimulation occurred based on the portion of the heart sound signal. | 11-22-2012 |
20120303084 | SECURE AND EFFICACIOUS THERAPY DELIVERY FOR A PACING ENGINE - The above-described methods and apparatus are believed to be of particular benefit for patients suffering heart failure including cardiac dysfunction, chronic HF, and the like and all variants as described herein and including those known to those of skill in the art to which the invention is directed. It will understood that the present invention offers the possibility of monitoring and therapy of a wide variety of acute and chronic cardiac dysfunctions. The current invention provides systems and methods for delivering therapy for cardiac hemodynamic dysfunction via the innervated myocardial substrate receives one or more discrete pulses of electrical stimulation during the refractory period of said innervated myocardial substrate. | 11-29-2012 |
20130030481 | MORPHOLOGY-BASED DISCRIMINATION ALGORITHM BASED ON RELATIVE AMPLITUDE DIFFERENCES AND CORRELATION OF IMPRINTS OF ENERGY DISTRIBUTION - Techniques for morphologic discrimination between beats of a tachyarrhythmia episode are described for selecting delivery of appropriate therapy. An exemplary method comprises nonordered binning of digitized amplitude values of signals associated with cardiac depolarizations. Monomorphic VT is discriminated from polymorphic VT without signal alignment. One exemplary method involves sensing electrical signals associated with depolarizations of a patient's heart during a tachyarrhythmia episode. The sensed electrical signals are converted to digital values and stored. The stored digital values are normalized and binned. At most, 5 pairs of beats or depolarizations are compared for morphologic similarity by determining the similarity between the binned values associated with each pair. The result of the comparison is used to select and deliver therapy to the patient. | 01-31-2013 |
20130030484 | SYSTEM AND METHOD FOR PACING PARAMETER OPTIMIZATION USING HEART SOUNDS - A medical device system and associated method predict a patient response to a cardiac therapy. The system includes for delivering cardiac pacing pulses to a patient's heart coupled to a cardiac sensing module and a cardiac pacing module for generating cardiac pacing pulses and controlling delivery of the pacing pulses at multiple pace parameter settings. An acoustical sensor obtains heart sound signals. A processor is enabled to receive the heart sound signals, derive a plurality of heart sound signal parameters from the heart sound signals, and determine a trend of each of the plurality of heart sound signal parameters with respect to the plurality of pace parameter settings. An external display is configured to present the trend of at least one heart sound parameter with respect to the plurality of pace parameter settings. | 01-31-2013 |
20130053716 | SYSTEM AND METHOD FOR PROFILING A PATIENTS HEMODYNAMIC RESPONSE BASED ON HEART SOUNDS - A medical device system includes electrodes for delivering cardiac pacing pulses to a patient's heart, a cardiac sensing module coupled to the electrodes and a cardiac pacing module coupled to the electrodes for generating cardiac pacing pulses. An acoustical sensor is used for obtaining heart sound signals. The system includes a processor that is configured to establish multiple conditions during which heart sound signals are received. The processor derives heart sound signal parameters from the heart sound signals and determines a heart sound profile comprising a trend of each of the heart sound signal parameters with respect to the multiple established conditions. | 02-28-2013 |
20130053906 | MORPHOLOGY-BASED PRECURSOR TO TEMPLATE MATCHING COMPARISION - One or more embodiments of the present disclosure relates to a method and/or system for classifying and/or treating heart rhythms. The present disclosure involves sensing electrical signals associated with depolarizations of a patient's heart. The sensed electrical signals are converted to digital values and storing the digital values. Normalizing solely a maximum and a minimum value of the stored digital values associated with a depolarization of the patient's heart without normalizing other stored digital values of the depolarization is another aspect of the present disclosure. The maximum and minimum values associated with the depolarization are compared to maximum and minimum values associated with a template derived from signals indicative of a heart depolarization of known type. A determination is made as to whether a match exists between the maximum and minimum values associated with the depolarization to the maximum and minimum values associated with a template. | 02-28-2013 |
20130165986 | DETECTION OF TARGET VEIN FOR CRT THERAPY - A method for selecting a target vein for left ventricular lead placement for cardiac resynchronization therapy includes determining electrical dispersion for the first coronary vein by calculating the difference between (i) activation time at a location of the vein that has the latest activation time of a plurality of locations in the vein and (ii) activation time at a location that has the earliest activation time of the plurality of locations. The method may further include (ii) determining whether the magnitude of the electrical dispersion for the vein meets or exceeds a predetermined threshold selecting the vein if the vein meets or exceeds the predetermined threshold; or (ii) selecting, among several veins, the vein that has the highest electrical dispersion. | 06-27-2013 |
20130165987 | FAULT TOLERANT PACING - Methods and/or devices may be configured to monitor the performance of pacing therapy and provide fault-tolerant operation to provide therapy in the event of certain failure modes occurring in the pacing delivery circuits, leads, and/or lead/tissue interfaces. Generally, the methods and/or devices may provide fault-detection, fault-recovery and fault-handling to, e.g., handle potential faults. | 06-27-2013 |
20130237872 | HEART SOUND SENSING TO REDUCE INAPPROPRIATE TACHYARRHYTHMIA THERAPY - Techniques for reducing inappropriate tachyarrhythmia therapy and associated medical device systems are described. In some examples a processor is enabled to receive a cardiac electrical signal representative of electrical activity of a heart of a patient and provide an indication of cardiac electrical signal reliability. A heart sound analyzing module is enabled to receive the indication of cardiac electrical signal reliability and a heart sound signal representing sounds generated by the heart of the patient and generated by a heart sound sensor. The heart sound analyzing module selectively determines an ensemble averaged heart sound signal or detects a plurality of heart sounds from the heart sound signal in response to the indication of cardiac electrical signal reliability. | 09-12-2013 |
20130268017 | HEART-SOUNDS BASED ADAPTIVE CARDIAC RESYNCHRONIZATION THERAPY TIMING PARAMETER OPTIMIZATION SYSTEM - A medical device and associated method for controlling a cardiac pacing therapy sense a first cardiac signal including events corresponding to cardiac electrical events and a second cardiac signal including events corresponding to cardiac hemodynamic events. A processor is enabled to measure a cardiac conduction time interval using the first cardiac signal and control a signal generator to deliver a pacing therapy. A pacing control parameter is adjusted to a plurality of settings during the pacing therapy delivery. A hemodynamic parameter value is measured from the second cardiac signal during application of each of the control parameter settings. The processor identifies an optimal setting from the plurality of settings and solves for a patient-specific equation defining the pacing control parameter as a function of the cardiac conduction time interval. | 10-10-2013 |
20130289640 | HEART SOUND-BASED PACING VECTOR SELECTION SYSTEM AND METHOD - A system and method for generating a pacing vector selection table senses a heart sound signal generated by a heart sound sensor and representing sounds generated by the heart of the patient. A processor controls the sequential selection of a pacing electrode vectors from electrodes positioned along a heart chamber. Pacing pulses are delivered via the sequentially selected plurality of pacing electrode vectors. The processor receives the heart sound signal, determines a plurality of different pacing responses using the heart sound signal for each of the of pacing electrode vectors, and generates a pacing vector selection table listing the plurality of different pacing responses for each of the plurality of pacing electrode vectors. | 10-31-2013 |
20140100623 | METHOD AND APPARATUS FOR ARRHYTHMIA DETECTION IN A MEDICAL DEVICE - A method and device for detecting arrhythmias in a patient that includes electrodes positioned subcutaneously within the patient, a microprocessor, coupled to the electrodes, determining one of a sequence of the sensing of cardiac signals by the electrodes and a duration between the sensing of cardiac signals by the electrodes, and control circuitry delivering a therapy in response to one of the determined sequence and the determined duration. | 04-10-2014 |
20140114372 | TRACKING PACING EFFECTIVENESS BASED ON WAVEFORM FEATURES - Methods and/or devices may be configured to track effectiveness of pacing therapy by monitoring two or more electrical vectors of the patient's heart during pacing therapy and analyzing at least one feature of a morphological waveform within each of the two or more electrical vectors. | 04-24-2014 |
20140371807 | METRICS OF ELECTRICAL DYSSYNCHRONY AND ELECTRICAL ACTIVATION PATTERNS FROM SURFACE ECG ELECTRODES - A method and system of cardiac pacing is disclosed. A baseline rhythm is determined using a plurality of body-surface electrodes. A set of baseline functional electrical metrics is determined in response to determining the baseline rhythm. Resynchronization pacing is delivered using a right ventricular electrode and a pacing left ventricular electrode or only with a left ventricular electrode. A set of functional electrical metrics relating to cardiac depolarization and repolarization is determined in response to resynchronization pacing. A determination is made as to whether relative reduction of at least one functional electrical metric from the set of functional electrical metrics exceeds X % of its corresponding value from the set of baseline functional electrical metrics. A determination is made as to whether an absolute value of at least one electrical metric from the set of the functional electrical metrics is less than Y ms. A determination is made as to whether a site is responsive to cardiac resynchronization therapy (CRT). | 12-18-2014 |
20140371808 | METRICS OF ELECTRICAL DYSSYNCHRONY AND ELECTRICAL ACTIVATION PATTERNS FROM SURFACE ECG ELECTRODES - A method and system of cardiac pacing is disclosed. A baseline rhythm is determined using a plurality of body-surface electrodes. A set of baseline functional electrical metrics is determined in response to determining the baseline rhythm. Resynchronization pacing is delivered using a right ventricular electrode and a pacing left ventricular electrode or only with a left ventricular electrode. A set of functional electrical metrics relating to cardiac depolarization and repolarization is determined in response to resynchronization pacing. A determination is made as to whether relative reduction of at least one functional electrical metric from the set of functional electrical metrics exceeds X % of its corresponding value from the set of baseline functional electrical metrics. A determination is made as to whether an absolute value of at least one electrical metric from the set of the functional electrical metrics is less than Y ms. A determination is made as to whether a site is responsive to cardiac resynchronization therapy (CRT). | 12-18-2014 |