Entries |
Document | Title | Date |
20080208070 | Defibrillator with Automatic Shock First/Cpr First Algorithm - An automated external defibrillator (AED) with an improved rescue protocol is described which follows a “shock first” or a “CPR first” rescue protocol after identification of a treatable arrhythmia, depending upon an estimate of the probability of successful resuscitation made from an analysis of a patient parameter measured at the beginning of the rescue. | 08-28-2008 |
20090062671 | PERIODIC SAMPLING OF CARDIAC SIGNALS USING AN IMPLANTABLE MONITORING DEVICE - In a method of diagnosing an atrial fibrillation or atrial flutter condition, a monitoring device implanted in a subject acquires strips of a subcutaneous ECG signal of a predetermined length. The strips are acquired at regular, periodic intervals, and the timing of when the strips are acquired is not triggered by analysis of the subcutaneous ECG signal by the monitoring device. The acquired subcutaneous ECG strips are stored in memory of the implanted monitoring device, and transmitted from the implanted monitoring device for receipt by an external analysis system. In the external analysis system, the received subcutaneous ECG strips are processed to generate information for an assessment of an atrial fibrillation or atrial flutter burden for the subject. | 03-05-2009 |
20090112110 | System for Cardiac Medical Condition Detection and Characterization - A system and method provides monitoring for atrial fibrillation. A data acquisition processor acquires a cardiac signal data stream from a patient and a wave detector detects an R-wave in a cardiac signal of the data stream. A T-wave in the cardiac signal occurring after the detected R-wave and a Q-wave in a subsequent cardiac signal of the data stream is also detected by the wave detector. A filter provides signal gating and extraction of data representing a Region of Interest (ROI) time window from the detected T-wave to the Q-wave. An integration processor detects characteristics of a P wave signal occurring within the ROI time window. At least one of the detected P wave characteristics is compared to characteristics derived from data representing at least one P wave signal and generating an output signal in response to the comparison for use in determining if the patient is in atrial fibrillation. | 04-30-2009 |
20090118630 | METHOD AND APPARATUS FOR CARDIAC ARRHYTHMIA CLASSIFICATION USING SAMPLE ENTROPY - An implantable medical device includes an arrhythmia detection and classification system that classifies an arrhythmia episode based on an irregularity parameter and/or a complexity parameter. The arrhythmia episode is detected from a cardiac signal. The irregularity parameter is indicative of the degree of cycle length irregularity of the cardiac signal and the complexity parameter is indicative of the degree of morphological complexity of the cardiac signal. One example of the irregularity parameter is an irregularity sample entropy, or a parameter related to the irregularity sample entropy, computed to indicate the cycle length irregularity. One example of the complexity parameter is a complexity sample entropy, or a parameter related to the complexity sample entropy, computed to indicate the morphological complexity. In one embodiment, the detected arrhythmia episode is classified using both the irregularity parameter and the complexity parameter. | 05-07-2009 |
20090264783 | SYSTEMS AND METHODS FOR IMPROVED ATRIAL FIBRILLATION (AF) MONITORING - Methods and systems described herein are especially useful wherein monitoring for atrial fibrillation (AF) is based on RR interval variability as measured from an electrocardiogram (ECG) signal. An activity threshold, which can be patient specific, is obtained. Patient activity is monitored. Based on the monitored patient activity and the activity threshold, there is a determination of when it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity. When it has been determined that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, whether and/or how AF monitoring is performed is modified. | 10-22-2009 |
20090270749 | DEVICE AND METHOD FOR DETECTING ATRIAL FIBRILLATION - Detection of atrial fibrillation involves detecting a plurality of ventricular events and obtaining a series of probabilities of AF, each corresponding to a probability of AF for a different beat window having a plurality of ventricular events. AF onset is detected when one or each of a plurality of consecutive AF probabilities satisfies an AF trigger threshold. AF termination is detected when one or each of a plurality of consecutive AF probabilities does not satisfy the AF trigger threshold. A probability of AF is obtained using one or more of a probability of AF that is based on the presence of irregularity of the ventricular events (P | 10-29-2009 |
20090270750 | Biopotential Signal Source Separation Using Source Impedances - Cardiac methods and devices that separate signals using at least two composite signals acquired at least at two input impedances. A target source impedance may be selected, and a cardiac signal may be separated from composite signals using the selected target source impedance. Medical systems include a cardiac device having a housing that provides amplification circuitry configured to have a first amplifier input impedance and a second amplifier input impedance, such as using two separate circuits or switching between two input impedances. One or more electrode assemblies are coupled to the amplification circuitry. A signal processor is provided in the housing configured to separate a source signal using a first composite signal detected at the first input impedance and a second composite signal detected at the second input impedance. The phase response of the first input amplifier circuit is about equal to that of the second input amplifier circuit. | 10-29-2009 |
20090275849 | Methods for Detection of Cardiac Arrhythmias - A method for calculating a variability value that is indicative of AF by obtaining a signal sequence of a plurality of RR intervals by monitoring electrical activity of a patient's heart. Each RR interval is converted into an instantaneous heart rate value and sorted into ascending order. The difference between each successive heart rate is calculated, discarding the two largest differences. The variability value is calculated by adding the retained differences. | 11-05-2009 |
20090299205 | DISCRIMINATION OF VENTRICULAR TACHYCARDIA FROM SUPRAVENTRICULAR TACHYCARDIA - This disclosure describes various techniques for discriminating supraventricular tachycardia (SVT) from ventricular tachycardia (VT). As one example, a method includes detecting a tachycardia rhythm, identifying a rate of change in heart rate corresponding to the tachycardia rhythm, identifying a rate of change in heart rate variability corresponding to the tachycardia rhythm, and classifying the tachycardia rhythm as at least one of supraventricular tachycardia or ventricular tachycardia based on the rate of change in heart rate and rate of change in heart rate variability. | 12-03-2009 |
20100010360 | Atrial Fibrillation Detection - Atrial fibrillation is detected in an electrical signal representative of a beating heart by measuring atrial activity over a time window of three or more beats, measuring beat interval variation over the time window and combining the measures of atrial activity and beat interval variation to produce an indication of an atrial fibrillation condition in the electrical signal. | 01-14-2010 |
20100030093 | PERIODIC BEAT DETECTION TO DETECT ARTIFACTS IN A CARDIAC ELECTROGRAM - Techniques for determining whether artifacts are present in a cardiac electrogram are described. According to one example, a medical device senses a cardiac electrogram via electrodes. The medical device determines a derivative, e.g., a second order derivative, the electrogram. The medical device detects beats within the derivative, e.g., by comparing a rectified version of the derivative to one or more thresholds determined based on a maximum of the rectified derivative. The medical device determines whether the beats are periodic, and determines whether artifacts are present in the cardiac electrogram based on the determination of whether the beats are periodic. The medical device may further determine whether tachyarrhythmia is present and/or whether the cardiac rhythm of the patient is treatable based on the determination of whether the beats are periodic. For example, the medical device may determine that an electrogram is not treatable when the beats are periodic. | 02-04-2010 |
20100056940 | Method, System and Computer Program Product for Non-Invasive Classification of Cardiac Rhythm - The invention relates to a method for analysis of cardiac rhythms, based on calculations of entropy and moments of interbeat intervals. The invention provides an optimal determination of segments of data that demonstrate statistical homogeneity, specifically with regard to moments and entropy. The invention also involves calculating moments and entropy on each segment with the goal of diagnosis of cardiac rhythm. More specifically, an absolute entropy measurement is calculated and provided as a continuous variable, providing dynamical information of fundamental importance in diagnosis and analysis. Through the present invention, standard histograms, thresholds, and categories can be avoided. | 03-04-2010 |
20100113954 | Device and Method to Detect The Severity of Ischemia and Heart Attack Risk - A device and method of detecting the severity of myocardial ischemia and heart attack risk is provided. The method includes obtaining an electrogram signal, determining T-wave measurements based on the electrogram signal, and determining ST segment measurements based on the electrogram signal. The method also includes identifying T-wave alternans based on the T-wave measurements and identifying ST segment changes based on the ST segment measurements. The method further includes correlating the T-wave alternans with the ST segment changes in order to detect a severity of ischemia. | 05-06-2010 |
20100168597 | ZONELESS TACHYARRHYTHMIA DETECTION WITH REAL-TIME RHYTHM MONITORING - A method of using an implantable medical device (IMD) comprising monitoring a ventricular contraction rate of a subject, monitoring an atrial contraction rate of the subject, declaring tachyarrhythmia if the ventricular contraction rate exceeds the atrial contraction rate, and declaring a slow tachyarrhythmia when the ventricular rate is less than a specified tachyarrhythmia detection rate. | 07-01-2010 |
20100174206 | Method to discriminate arrhythmias in cardiac rhythm management devices - The present invention describes a covariance-based algorithm for the specific and sensitive discriminantion of heart rhythms in cardiac rhythm management devices. | 07-08-2010 |
20100204598 | Apparatus And Method For Cardiac Ablation - A system and method for cardiac mapping and ablation include a multi-electrode catheter introduced percutaneously into a subject's heart and deployable adjacent to various endocardial sites. The electrodes are connectable to a mapping unit, an ablation power unit a pacing unit, all of which are under computer control. Intracardiac electrogram signals emanated from a tachycardia site of origin are detectable by the electrodes. Their arrival times are processed to generate various visual maps to provide real-time guidance for steering the catheter to the tachycardia site of origin. In another aspect, the system also include a physical imaging system which is capable of providing different imaged physical views of the catheter and the heart. These physical views are incorporated into the various visual maps to provide a more physical representation. Once the electrodes are on top of the tachycardia site of origin, electrical energy is supplied by the ablation power unit to effect ablation. | 08-12-2010 |
20100249626 | DISCRIMINATING BETWEEN TACHYCARDIAS OF VENTRICULAR ORIGIN AND SUPRA ENTRICULAR ORIGIN, METHODS AND APPARATUS - An active medical device able to discriminate between tachycardias of ventricular origin and of supra-ventricular origin. Two distinct temporal components (UnipV, BipV) are obtained corresponding to two EGM signals of ventricular electrograms. The diagnosis operates in at least two-dimensional space to determine, from the variations of one temporal component as a function of the other temporal component, a 2D characteristic representative of a heart beat and, this, for a reference beat collected in Sinus Rhythm (SR) in the absence of tachycardia episodes, and for a heart beat in Tachycardia. The discrimination of the tachycardia type, VT or SVT, is then realized by a classifier operating a comparison of the two current and reference 2D characteristics. | 09-30-2010 |
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 |
20100262029 | NEEDLE IMPLANTABLE ATRIAL FIBRILLATION MONITOR AND METHODS FOR USE THEREWITH - A needle implantable atrial fibrillation monitor includes a plurality of terminals that generate a terminal voltage when the needle implantable atrial fibrillation monitor is implanted in a patient's body. An analog processing circuit generates a monitoring signal based on the terminal voltage. An analog to digital converter converts the monitoring signal to monitoring data. A processor analyzes the monitoring data, generates events and compresses the event data and that generates compressed data in response thereto. A memory stores the compressed data. An RF interface transmits the compressed data to a base station via RF signaling when the needle implantable atrial fibrillation monitor is implanted in the patient's body. | 10-14-2010 |
20100262030 | RHYTHM DISCRIMINATION OF SUDDEN ONSET AND ONE-TO-ONE TACHYARRHYTHMIA - This document discusses, among other things, systems and methods to discriminate between a ventricular tachyarrhythmia (VT) and a supraventricular tachyarrhythmia (SVT), such as upon detecting sudden onset and one-to-one tachycardia. In certain examples, a detected tachyarrhythmia is analyzed to determine whether it is sudden onset and 1:1. If so, a first fast beat is identified. One or more ventricular intervals in close proximity to the first fast beat are analyzed to determine an initial classification of either VT or SVT. The initial classification is used to adjust a morphological feature correlation coefficient (FCC) threshold. A morphology analysis is performed with the adjusted FCC threshold value to yield a secondary classification. | 10-14-2010 |
20100268103 | Cardiac Arrhythmia Report - Systems, devices, methods, and techniques relating to generating and presenting information related to heart rate data. In one aspect, a system includes a monitoring device configured to obtain physiological data for a living being and to generate annotation data based on the physiological data for a total time period, a processing system configured to obtain the annotation data via a communication channel from the monitoring device and to generate for display based on the annotation data a daily patient report that includes, a chart showing summary statistical data for a proportion of a total monitored time period spent in cardiac arrhythmia for each of a plurality of days and summary statistical data for a proportion of the total monitored time period not spent in cardiac arrhythmia for each of the plurality of days. | 10-21-2010 |
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 |
20100274149 | METHODS FOR DETECTING ATRIAL TACHYARRHYTHMIA IN IMPLANTABLE DEVICES WITHOUT DEDICATED ATRIAL SENSING - An apparatus comprises an implantable cardiac signal sensing circuit configured to provide a sensed depolarization signal from a ventricle and a processor. The processor includes a signal analyzer module and a tachyarrhythmia discrimination module. The signal analyzer module is configured to determine a measure of stability of ventricular (V-V) depolarization intervals using the depolarization signal, and determine a rate of change of the measure of stability. The tachyarrhythmia discrimination module is configured to detect an episode of tachyarrhythmia using the depolarization signal, determine whether the detected tachyarrhythmia is indicative of atrial tachyarrhythmia using the determined rate of change, and provide the determination to a user or process. | 10-28-2010 |
20100280401 | ATRIAL ARRHYTHMIA DETECTION AND DISCRIMINATION BASED ON INTRACARDIAC IMPEDANCE - An apparatus comprises an implantable impedance sensing circuit configured to sense an atrial impedance signal when coupled to a plurality of implantable electrodes, and an impedance signal analyzer circuit configured to detect a sudden change in a characteristic of the sensed atrial impedance signal that indicates atrial tachyarrhythmia. The impedance signal analyzer circuit classifies the atrial tachyarrhythmia indication as ST when the detected sudden change satisfies an ST threshold value of the characteristic, classifies the atrial tachyarrhythmia indication as AT when the detected sudden change satisfies an AT threshold value of the characteristic that is different from the ST threshold value, classifies the atrial tachyarrhythmia indication as AF when the detected sudden change satisfies an AF threshold value of the characteristic that is different from the ST and AT amplitude threshold values, and provides a classification of the tachyarrhythmia to a user or process. | 11-04-2010 |
20100317984 | TACHYARRHYTHMIA DETECTION USING DYNAMIC DURATION - An apparatus comprises an implantable cardiac signal sensing circuit configured to produce a sensed cardiac signal representative of cardiac activity of a subject and a controller communicatively coupled to the cardiac signal sensing circuit. The controller includes a sensing module configured to detect a cardiac depolarization using the sensed cardiac signal and an arrhythmia detection module. The arrhythmia detection module is configured to detect a depolarization rate or interval that satisfies a first tachyarrhythmia detection rate zone threshold, adjust a specified detection duration threshold for the tachyarrhythmia detection zone according to the detected depolarization rate, declare that the detected depolarization rate is an episode of tachyarrhythmia when the detected depolarization rate is sustained for the adjusted detection duration threshold, and provide an indication of the tachyarrhythmia to a user or process. | 12-16-2010 |
20100331713 | POST-EXERCISE ARRHTYMIA DETECTION - Post-exercise arrhythmias are detected by an implantable medical device. In some aspects, post-exercise arrhythmia may be prognostic of a worsening cardiovascular condition. Thus, the detection of post-exercise arrhythmia may be used as an indicator for adjusting the therapy prescribed for a patient. In some aspects post-exercise arrhythmia are detected if a patient is exercising at a level that equals or exceeds a threshold exercise level. In some aspects, therapy for a patient is modified if the detected post-exercise arrhythmia exceeds a threshold arrhythmia level. In some aspects therapy for a patient is modified if ischemia is detected in conjunction with post-exercise arrhythmia. | 12-30-2010 |
20110021934 | BLENDING CARDIAC RHYTHM DETECTION PROCESSES - Systems and methods are described for classifying a cardiac rhythm. A cardiac rhythm is classified using a classification process that includes a plurality of cardiac rhythm discriminators. Each rhythm discriminator provides an independent classification of the cardiac rhythm. The classification process is modified if the modification is likely to produce enhanced classification results. The rhythm is reclassified using the modified classification process. | 01-27-2011 |
20110034817 | DISCRIMINATION OF SUPRAVENTRICULAR TACHYCARDIA AND VENTRICULAR TACHYCARDIA EVENTS - A method and system for discrimination of supraventricular tachycardia and ventricular tachycardia events. Morphological features points are extracted from normal sinus rhythm (NSR) complexes and used to generate a NSR template. A numerical convolution is performed using the NSR template and the feature points for each sensed NSR to give a NSR filter output. Using a plurality of NSR complexes, a median NSR filter output template is determined, where the median NSR filter output template has a median value for each value in the NSR filter output. The median NSR filter output template is then used during a tachycardia event to distinguish tachycardia events as either ventricular tachycardia events or supraventricular tachycardia events. | 02-10-2011 |
20110144512 | THERAPY-SELECTION METHODS FOR IMPLANTABLE HEART MONITORS - An implantable heart-monitoring device comprising one or more leads for sensing electrical signals of a patient's heart a therapy circuit for delivering pharmaceuticals to the patient; and a monitoring circuit coupled to the one or more leads and to the therapy circuit, the monitoring circuit for monitoring heart activity of the patient through one or more of the leads, the monitoring circuit operable to: determine a minimum interval from a set of two or more intervals based on sensed heart activity, determine a range parameter based on a difference between a first subset and second subset of the intervals, determine a dispersion parameter quantifying dispersion of a subset of the intervals, and to determine an assessment value for the set of intervals, based on the minimum interval, the range parameter, the dispersion index. | 06-16-2011 |
20110166468 | SYSTEM AND METHOD FOR PROCESSING AND PRESENTING ARRHYTHMIA INFORMATION TO FACILITATE HEART ARRHYTHMIA IDENTIFICATION AND TREATMENT - A system and method for presenting information relating to heart data can involve operations including identifying arrhythmia events in physiological data obtained for a living being, receiving human assessments of at least a portion of the arrhythmia events, determining a measure of correlation between the human assessments and the identified events, and selectively presenting information regarding the identified events based on the measure of correlation. The operations can also include identifying atrial fibrillation events in physiological data obtained for a living being, obtaining heart rate data for the living being, and presenting information regarding the heart rate data and duration of the atrial fibrillation events together with a common time scale to pictographically represent heart rate trend with atrial fibrillation burden during a defined time period. | 07-07-2011 |
20110190650 | Computerized Systems and Methods for Stability-Theoretic Prediction and Prevention of Sudden Cardiac Death - Systems, methods and computer-readable media are provided for automatic identification of patients according to near-term risk of ventricular arrhythmias and sudden cardiac death (SCD). Embodiments of the invention are directed to event prediction, risk stratification, and optimization of the assessment, communication, and decision-making to prevent SCD, and in one embodiment take the form of a platform for wearable, mobile, unteathered monitoring devices with embedded decision support. Thus embodiments relate to automatically identifying persons at risk for arrhythmias and SCD through the use of noninvasive, portable, wearable electronic device and sensors equipped with signal-processing software and statistical predictive algorithms that calculate stability-theoretic measures derived from the digital electrocardiogram timeseries acquired by the device. The measurements and predictive algorithms embedded within the device provide for unsupervised use in the home or in general acute-care and chronic-care venues and afford a degree of robustness against variations in individual anatomy and sensor placement. | 08-04-2011 |
20110208079 | REAL TIME ATRIAL FIBRILLATION MONITORING - An atrial fibrillation (AF) monitor extracts two P wave features and an R-R interval feature from a sequence of ECG waveforms. The features are used by a classifier to classify a heart rhythm as AF or non-AF. The AF classification results may be further processed to reduce false alarm reporting. The AF classification results are used by an AF burden calculator to report AF burden in real time. | 08-25-2011 |
20110218449 | Therapy Delivery for Identified Tachyarrhythmia Episode Types - Methods and systems for identifying tachyarrhythmia episode types and delivering therapy to mitigate the identified tachyarrhythmia episode types are described. Electrogram signals of cardiac activity are sensed and stored by an implantable cardiac device. Tachyarrhythmia episodes are detected and tachyarrhythmia episode types are identified based on characteristics of the electrogram signals. In preparation for performing ablation, a tachyarrhythmia episode is induced. The features of the induced tachyarrhythmia episode are compared to characteristics of the identified episode types. A similarity between the induced tachyarrhythmia episode and at least one of the episode types identified from the stored electrogram signals is indicated to facilitate performing the ablation. | 09-08-2011 |
20110224566 | LEAD INTEGRITY TESTING DURING SUSPECTED TACHYARRHYTHMIAS - Techniques for performing a lead integrity test during a suspected tachyarrhythmia are described. An implantable medical device (IMD) may perform the test prior to delivering a therapeutic shock to treat the suspected tachyarrhythmia and, in some cases, may withhold the shock based on the test. In some examples, the IMD measures an impedance of a lead a plurality of times during the suspected tachyarrhythmia. In some examples, the IMD measures the impedance a plurality of times between two sensed events of the suspected tachyarrhythmia. The IMD or another device may determine a variability of, or otherwise compare, the measured impedances to evaluate the integrity of the lead. Instead of or in addition to withholding a shock, the IMD or another device may change a sensing or stimulation vector of the IMD, or provide an alert to a user, if the integrity test indicates a possible lead integrity issue. | 09-15-2011 |
20110263996 | METHODS FOR ESTIMATING THE RISK FOR VENTRICULAR ARRHYTHMIAS IN A SUBJECT - The present invention relates to methods for predicting the risk for ventricular arrhythmias in a subject who has previously suffered a myocardial infarction (MI) or suffers from a primary cardiomyopathy, said method comprising measuring the myocardial mechanical dispersion in said subject and estimating the risk for ventricular arrhythmias based on said measurements. Similar the invention relates to a method for evaluating whether a subject is a candidate for implantable cardioverter-defibrillator (ICD) therapy. | 10-27-2011 |
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 |
20110270109 | METHOD AND APPARATUS FOR DETECTING AND DISCRIMINATING TACHYCARDIA - A medical device and associated method obtaining cardiac event intervals corresponding to a tachycardia interval. Evidence of a rhythm breaking point is obtained in response to sensing a cardiac event having a morphology corresponding to a supraventricular beat. A non-treatable rhythm is detected in response to the plurality of cardiac event intervals and the evidence of the rhythm breaking point. | 11-03-2011 |
20110270110 | METHOD AND APPARATUS FOR DETECTING AND DISCRIMINATING TACHYCARDIA - A medical device and associated method for monitoring a patient's heart rhythm sensing a cardiac signal determine whether a cardiac signal is noise corrupted by obtaining cardiac signal pulses and generating a pulse amplitude threshold in response to the plurality of signal pulses. The number of signal sample points exceeding the pulse amplitude threshold in each of the of signal pulses is computed. The cardiac signal is determined to be noise corrupted or non-corrupted in response to the computed number of signal sample points. | 11-03-2011 |
20110288427 | DISCRIMINATION OF SUPRAVENTRICULAR TACHYCARDIA AND VENTRICULAR TACHYCARDIA EVENTS - A method and system for discrimination of supraventricular tachycardia and ventricular tachycardia events. Morphological features points are extracted from normal sinus rhythm (NSR) complexes and used to generate a NSR template. A numerical convolution is performed using the NSR template and the feature points for each sensed NSR to give a NSR filter output. Using a plurality of NSR complexes, a median NSR filter output template is determined, where the median NSR filter output template has a median value for each value in the NSR filter output. The median NSR filter output template is then used during a tachycardia event to distinguish tachycardia events as either ventricular tachycardia events or supraventricular tachycardia events. | 11-24-2011 |
20120035490 | WIRELESS CARDIAC PULSATILITY SENSING - An implantable medical device system and associated method monitor changes in transimpedance in a body tissue due to changes in cardiac pulsatility. A first dipole is used to deliver a non-stimulating electrical current. The first dipole includes a first electrode and a second electrode adapted to be deployed along a first body location. A second dipole is used to measure a voltage resulting from the non-stimulating electrical current being conducted through a portion of a patient's body. The second dipole includes a third electrode and a fourth electrode different than the first electrode and the second electrode and adapted to be deployed along a second body location spaced apart from the first body location. | 02-09-2012 |
20120035491 | RHYTHM DISCRIMINATION ENHANCEMENT - AV DRIVE - An apparatus comprises an implantable cardiac signal sensing circuit and a controller circuit. The implantable cardiac signal sensing circuit provides a sensed depolarization signal from a ventricle and a sensed depolarization signal from an atrium. The controller circuit includes a one-to-one detector circuit and a tachyarrhythmia discrimination circuit. The one-to-one detector circuit measures cardiac depolarization intervals of the atrium and the ventricle and determines whether a relationship of atrial depolarizations to ventricular depolarizations is substantially one-to-one. The tachyarrhythmia discrimination circuit increments a counter when detecting a shortening or prolonging of a V-V interval that immediately precedes the same shortening or prolonging of an A-A interval, classifies the episode as VT according to the counter, and provides the classification of the tachyarrhythmia episode to a user or process. | 02-09-2012 |
20120035492 | Atrial Tachyarrhythmia Detection using Selected Atrial Intervals - Methods and systems are directed to detecting atrial tachyarrhythmia. A plurality of A-A intervals is detected. The detected A-A intervals are selected and used to detect atrial tachyarrhythmia. Selecting A-A intervals may be based on determining that A-A intervals are qualified. Qualified A-A intervals may be determined if a duration of the particular A-A interval falls outside a predetermined duration range, for example. Qualified A-A intervals may also be determined based on events occurring between consecutively sensed atrial events of the particular A-A interval, and whether the duration of the particular A-A interval falls within the predetermined duration range, for example. | 02-09-2012 |
20120046566 | CLASSIFICATION OF SUPRAVENTRICULAR AND VENTRICULAR CARDIAC RHYTHMS USING CROSS CHANNEL TIMING ALGORITHM - A system and method for classifying cardiac complexes sensed during a tachycardia episode. A first cardiac signal and a second cardiac signal are sensed, where the first cardiac signal has a voltage. A first cardiac complex and a second cardiac complex of a cardiac cycle are detected in the first and second cardiac signal, respectively. A predetermined alignment feature is identified in the second cardiac complex. A datum is defined, or positioned, at a specified interval from the predetermined alignment feature of the second cardiac complex. Voltage values are then measured from the first cardiac complex at each of two or more measurement intervals from the datum. The voltage values are then compared voltage values measured from NSR cardiac complexes to classify the first cardiac complex is either a ventricular tachycardia complex or a supraventricular tachycardiac complex. | 02-23-2012 |
20120165692 | IMPLANTABLE MEDICAL DEVICE AND A METHOD FOR USE IN AN IMPLANTABLE MEDICAL DEVICE - An implantable medical device is connectable to at least three electrodes, and includes an immittance measurer that performs immittance measurements within the heart of a patient using at least three electrodes coupled to the device, with at least one of the electrodes is arranged in an atrium of the patient's heart. The medical device further includes an immittance converter that converts the immittance measurement values into individual near-field immittance values of the at least one electrode arranged in an atrium, an atrial dilatation detector that detects atrial dilatation based upon the individual near-field immittance values, and that determines atrial dilatation values in dependence thereon, and an atrial fibrillation risk determiner that determines an atrial fibrillation risk index based upon the atrial dilatation values. | 06-28-2012 |
20120179057 | BLENDING CARDIAC RHYTHM DETECTION PROCESSES - Systems and methods are described for classifying a cardiac rhythm. A cardiac rhythm is classified using a classification process that includes a plurality of cardiac rhythm discriminators. Each rhythm discriminator provides an independent classification of the cardiac rhythm. The classification process is modified if the modification is likely to produce enhanced classification results. The rhythm is reclassified using the modified classification process. | 07-12-2012 |
20120232417 | Signal Analysis System for Heart Condition Determination - A system for heart performance characterization and abnormality detection includes an interface for receiving sampled data representing an electrical signal indicating electrical activity of a patient heart over multiple heart beat cycles. A signal processor automatically, decomposes the received sampled data to multiple different subcomponent signals in the time domain. The signal processor associates individual decomposed subcomponents with corresponding different cardiac rotors and determined characteristics of the subcomponents indicating relative significance of the rotors in a cardiac atrial condition. A reproduction device provides data indicating the subcomponent characteristics indicating relative significance of the rotors in a cardiac atrial condition. | 09-13-2012 |
20120289847 | IMPLANTABLE MEDICAL DEVICE SENSING AND SELECTING WIRELESS ECG AND INTRACARDIAC ELECTROGRAM - A CRM system enhances intracardiac electrogram-based arrhythmia detection using a wireless electrocardiogram (ECG), which is a signal sensed with implantable electrodes and approximating a surface ECG. In one embodiment, an intracardiac electrogram allows for detection of an arrhythmia, and the wireless ECG allows for classification of the detected arrhythmia by locating its origin. In another embodiment, the wireless ECG is sensed as a substitute signal for the intracardiac electrogram when the sensing of the intracardiac electrogram becomes unreliable. In another embodiment, a cardiac signal needed for a particular purpose is selected from one or more intracardiac electrograms and one or more wireless ECGs based on a desirable signal quality. In another embodiment, intracardiac electrogram-based arrhythmia detection and wireless ECG-based arrhythmia detection confirm with each other before indicating a detection of arrhythmia of a certain type. | 11-15-2012 |
20120310102 | METHODS AND APPARATUSES FOR CARDIAC ARRHYTHMIA CLASSIFICATION USING DYNAMIC BEATDRIVEN MORPHOLOGICAL FEATURE EXTRACTION - An implantable cardioverter/defibrillator (ICD) includes a tachyarrhythmia detection and classification system that classifies tachyarrhythmias based on a morphological analysis of arrhythmic waveforms and a template waveform. Correlation coefficients each computed between morphological features of an arrhythmic waveform and morphological features of the template waveform provide for the basis for classifying the tachyarrhythmia. In one embodiment, morphological features are collected from a sensed arrhythmic waveform, and temporally corresponding morphological features are extracted a stored template waveform. | 12-06-2012 |
20130030314 | DEVICES, SYSTEMS AND METHODS TO PERFORM ARRHYTHMIA DISCRIMINATION BASED ON THE ATRIAL AND VENTRICULAR ACTIVATION TIMES - Described herein are implantable systems and devices, and methods for use therewith, that can be used to perform arrhythmia discrimination based on activation times. A plurality of different sensing vectors are used to obtain a plurality of IEGMs that collectively enable electrical activations to be detected in the left atrial (LA) chamber, the right atrial (RA) chamber, and at least one ventricular chamber of a patient's heart. For each of a plurality of cardiac cycles, there is a determination, based on the plurality of obtained IEGMs, of an LA activation time, an RA activation time, and a ventricular activation time. Arrhythmia discrimination is then performed based on the determined activation times. | 01-31-2013 |
20130035605 | DETECTING HEMODYNAMIC STABILITY DURING ARRHYTHMIA USING THE CHANGES IN ATRIAL ACTIVATION - Detected changes in atrial activation can be used to discriminate between hemodynamically stable and hemodynamically unstable tachyarrhythmias. | 02-07-2013 |
20130066222 | SYSTEMS AND METHODS FOR DETECTING FAR-FIELD OVERSENSING BASED ON SIGNALS SENSED BY THE PROXIMAL ELECTRODE OF A MULTIPOLAR LV LEAD - A device senses cardioelectrical signals using a right atrial (RA) lead, which might include far-field R-waves as well as near-field P-waves. The device concurrently senses events using a proximal electrode of an LV lead, which can sense both P-waves and R-waves as substantially near-field events. Suitable templates are then applied to the signals sensed via the proximal LV electrode to identify the origin of the signals (e.g. atrial vs. ventricular) so as to properly classify the corresponding events sensed in the RA as near-field or far-field events. In this manner, far-field oversensing is conveniently detected. | 03-14-2013 |
20130079654 | EPISODE CLASSIFIER ALGORITHM - The present disclosure is directed to the classification of cardiac episodes using an algorithm. In various examples, an episode classification algorithm evaluates electrogram signal data from a near-field channel and a far-field channel. The episode classification algorithm classifies the cardiac episode based on the evaluation of the electrogram signal data for at least one of the near-field and far-field channels. In some examples, a cardiac episode being classified may be an episode that resulted in treatment being provided by an implantable medical device. Possible classifications of the cardiac episode may include, for example, unknown, inappropriate, appropriate, supraventricular tachycardia, ventricular tachycardia, ventricular fibrillation or ventricular over-sensing. | 03-28-2013 |
20130085406 | ELECTROGRAM SUMMARY - 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. | 04-04-2013 |
20130102913 | Patient Readable Portable Atrial Fibrillation Detector - Systems and devices to gather data from a subject's heart, analyze said data to determine whether the subject is experiencing cardiac arrhythmia, and display results of said determining. Use, and display of cardiac condition information, are preferably simple and unambiguous to untrained users. | 04-25-2013 |
20130116585 | Ventricular Fibrillation Detection - Systems and techniques are disclosed for determining the onset and offset of a ventricular fibrillation event and for distinguishing ventricular fibrillation from noise. In some examples, an electrocardiogram (ECG) signal is obtained; a transform is applied to the ECG signal to obtain an analytical pair, the analytical pair including the ECG signal and the transformed ECG signal; a speed-amplitude is determined from the analytical pair; and an onset of a ventricular fibrillation event is identified based at least one of a value of a cost function of the speed-amplitude over a window and a quantity of occurrences the speed-amplitude crosses a threshold over the window. | 05-09-2013 |
20130116586 | USE OF DRONEDARONE OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF FOR THE PREPARATION OF A DRUG FOR THE PREVENTION OF ATRIAL FIBRILLATION - The present invention relates to the use of dronedarone or a pharmaceutically acceptable salt thereof for the preparation of a drug for the prevention of atrial fibrillation wherein said use comprises the following precaution of use steps:
| 05-09-2013 |
20130144180 | METHODS AND SYSTEMS FOR ATRIAL FIBRILLATION DETECTION - Methods and systems for automatic detection of Atrial Fibrillation (AF) are disclosed. The methods and systems use time-varying coherence functions (TVCF) to detect AF. The TVCF is estimated by the multiplication of two time-varying transfer functions (TVTFs). | 06-06-2013 |
20130178755 | ANALYZING ELECTROCARDIOGRAMS - An electrocardiogram (ECG) analyzing system for analyzing electrocardiogram (ECG) signals, the system including: a computing device including: a transformer for transforming an ECG signal into a time-frequency representation over a plurality of frequencies over a period of time; a calculator for calculating a magnitude of the time-frequency representation; an analyzer for analyzing a degree of clustering of a plurality of low-magnitude values in the time-frequency representation; and a diagnosing system for diagnosing whether ventricular fibrillation is present based on the degree of clustering. | 07-11-2013 |
20130184600 | SYSTEMS AND METHODS FOR FILTERING ECG ARTIFACTS - Systems and methods of processing raw electrocardiogram (ECG) waveform data of a patient into estimated real-time ECG waveform data. The method includes sensing at least one physical non-cardiac influence on the raw ECG waveform data, constructing a time domain computer model of the at least one physical, non-cardiac influence on the raw ECG waveform data, and adaptively filtering the raw ECG waveform data in the time domain using the constructed time domain computer model of the at least one physical non-cardiac influence on the raw ECG waveform data to form the estimated real-time ECG waveform data. The system can include an ECG device for collecting raw ECG waveform data, at least two ECG electrodes positioned on the patient and electrically coupled to the ECG device, and a processor coupled to the ECG device and configured to compute a time domain model of an artifact created by chest compressions. | 07-18-2013 |
20130197380 | Atrial Fibrillation Classification Using Power Measurement - An atrial fibrillation classification system collects celectrocardiogram signals and converts them to a frequency, time, or phase domain representation for analysis. An evaluation stage extracts energy density profile over a range of frequencies, time intervals, or phases, which is then summed and normalized to form dispersion metrics. The system then analyzes the dispersion metrics, in their respective domains, to determine whether a patient is experiencing an arrhythmia and then to classify the type of arrhythmia being experienced. | 08-01-2013 |
20130204149 | APPARATUS AND METHOD FOR GENERATING ATRIAL FIBRILLATION PREDICTION MODEL, AND APPARATUS AND METHOD FOR PREDICTING ATRIAL FIBRILLATION - An apparatus and a method to generate an atrial fibrillation prediction model, and an apparatus and a method to predict atrial fibrillation are provided. An atrial fibrillation (AF) prediction model generating apparatus includes a feature extractor configured to extract T-wave features in a predetermined time period from electrocardiogram data and generate a T-wave feature profile based on the extracted features, and a prediction model generator configured to classify the generated T-wave feature profile and generate an AF prediction model using the classified feature profile. | 08-08-2013 |
20130218037 | INTERBEAT INTERVAL MONITORING AND ECTOPIC BEAT REMOVAL - Disclosed is an apparatus and method for ambulatory, real-time detection of removal of ectopic beats by obtaining consecutive patient heartbeats, and recognizing an ectopic beat by detecting a signature short-long sequence in an interbeat interval of the obtained heartbeats, with the signature short-long sequence including an ectopic coupling interval followed by a compensatory pause between RR intervals. | 08-22-2013 |
20130245474 | METHOD AND APPARATUS FOR EVALUATING CARDIAC FUNCTION - The present invention relates to a method for assessing the electrical function of a heart, comprising the steps of:—(1) for each of a plurality of leads of an ECG, determining a value derived from the output of that lead and which corresponds to an action potential duration; (2) for each of the plurality of leads of the ECG, determining a value derived from the output of that lead and which corresponds to a diastolic interval; (3) for each of the plurality of leads of the ECG, determining a relationship between the determined values for action potential duration and for diastolic interval; (3) assessing the differences between the determined relationships for each of the plurality of leads. The invention further relates to apparatus and a computer program that may be used in the method. | 09-19-2013 |
20130245475 | RI MEASUREMENT/NOTIFICATION APPARATUS AND MEASUREMENT/NOTIFICATION PROGRAM - An RI measurement/notification apparatus includes: a displaying section configured to display waveform data of an intracardiac electrocardiogram; a waveform data acquiring section configured to acquire waveform data in a preset waveform data acquisition time period from an intracardiac electrocardiogram during atrial fibrillation; an RI calculating section configured to calculate an RI value based on the waveform data acquired by the waveform data acquiring section; and a notifying section configured to, in a case where the RI value calculated by the RI calculating section exceeds a preset threshold, notify that the value exceeds the threshold. | 09-19-2013 |
20130245476 | CARDIAC MUSCLE EXCITATION WAVEFORM DETECTOR - A cardiac muscle excitation waveform detector including: a waveform acquisition section that acquires, in a preset period, a waveform from an intracardiac electrocardiogram measured in middle of occurrence of atrial fibrillation; a waveform detection condition setting section that sets conditions for detecting a waveform of cardiac muscle excitation; and an excitation waveform detection section that detects a waveform of cardiac muscle excitation from the waveforms based on the conditions, wherein the waveform detection condition setting section includes a section that sets conditions based on a contour of a waveform to detect candidates for the waveform of cardiac muscle excitation, a section that sets a search period for searching for a waveform of cardiac muscle excitation; and a section that sets a preset period subsequent to detection as a detection exclusion period during which the candidate waveforms are not detected when the waveform of cardiac muscle excitation is detected. | 09-19-2013 |
20130274624 | METHOD AND APPARATUS FOR AUTOMATIC ARRHYTHMIA CLASSIFICATION WITH CONFIDENCE ESTIMATION - An arrhythmia classification system receives cardiac data from an implantable medical device, performs automatic adjudication of each cardiac arrhythmia episode indicated by the cardiac data, and generates episode data representative of information associated with the episode. The episode data include at least an episode classification resulting from the automatic adjudication of the episode and a confidence level in the episode classification. In one embodiment, the episode data further include key features rationalizing the automatic adjudication of the episode. | 10-17-2013 |
20130303926 | ATRIAL FIBRILLATION DETECTION - A method of detecting atrial fibrillation (AFib) includes receiving electrical signals representative of a beating heart and measuring atrial activity over a time window of three or more beats. The method may also include measuring beat interval variation over the time window and combining the measures of atrial activity and beat interval variation to produce an indication of an atrial fibrillation condition in the electrical signal. The method may further include producing the indication with a processing system. Measuring atrial activity may include measuring P waves, and measuring P waves may include analyzing a standard deviation of a PR interval. | 11-14-2013 |
20130324869 | USING INTRACARDIAC ELECTROGRAMS TO PREDICT LOCATION OF FIBROSIS AND AUTONOMIC NERVES IN THE HEART - A method of targeting fibrosis or autonomic nerve tissue for ablation in a subject is described. The method includes at least the following steps. The method includes performing at least one EGM analysis of a plurality of recorded atrial EGMs for a tissue in a region suspected of having fibrosis or autonomic nerve tissue. With regard to targeting fibrosis for ablation, the method includes determining one or more correlations of at least one AF EGM characteristic to a region having fibrosis from the plurality of recorded atrial EGMs for the tissue and determining whether the tissue contains dense fibrosis that would preclude effective ablation of the analysis region of the tissue. With regard to targeting autonomic nerve for ablation, the method includes determining whether one or more significant changes in EGM characteristics with autonomic blockade exist that would indicate the need to perform ablation of the analysis region of the tissue. | 12-05-2013 |
20130331719 | RESUSCITATION ENHANCEMENTS - A system including a sensor interface coupled to a processor. The sensor interface is configured to receive and process an analog electrocardiogram signal of a subject and provide a digitized electrocardiogram signal sampled over a first time period and a second time period that is subsequent to the first time period. The processor is configured to receive the digitized electrocardiogram signal, to analyze a frequency domain transform of the digitized electrocardiogram signal sampled over the first and second time periods and determine first and second metrics indicative of metabolic state of a myocardium of the subject during the first and second time periods, respectively, to compare the first and second metrics to determine whether the metabolic state of the myocardium of the subject is improving, and to indicate administration of an intervention to the subject in response to a determination that the metabolic state is not improving. | 12-12-2013 |
20140005562 | ATRIAL FIBRILLATION TREATMENT SYSTEMS AND METHODS | 01-02-2014 |
20140031708 | SYSTEM AND METHOD FOR IMPROVED COMPLEX FRACTIONATED ELECTROGRAM ABLATION - A computer-assisted method for quantitative characterization and treatment of ventricular fibrillation includes preprocessing a time series of an atrial fibrillation signal obtained from a patient, segmenting the time series of the AF signal into activation segments by the computer system, obtaining local activation waveforms (LAW) from the activation segments, determining degrees of similarity between the LAWs, and identifying one or more critical regions in the patient's atria if the LAWs have degrees of similarity exceeding a first threshold value. | 01-30-2014 |
20140046207 | Determination of site of origin for a natural electrical pulse in a living body - Techniques include determining a first vector of temporal changes in electrical data measured at multiple electrical sensors positioned at corresponding locations on a surface of a living body due to a natural electrical pulse. A different vector of temporal changes in electrical data measured at the same electrical sensors is determined due to each stimulated signal of multiple stimulated signals within the living body. Stimulated position data is received, which indicates a different corresponding position within the living body where each of the stimulated signals originates. The site of origin of the natural electrical pulse is determined based on the first vector and the multiple different vectors and the stimulated position data. Among other applications, these techniques allow the rapid, automatic determination of the site of origin of ventricular tachycardia arrhythmia (VT). | 02-13-2014 |
20140052012 | SYSTEMS AND METHODS FOR SELECTIVELY UPDATING CARDIAC MORPHOLOGY DISCRIMINATION TEMPLATES FOR USE WITH IMPLANTABLE MEDICAL DEVICES - Techniques are provided for updating a morphology template used to discriminate abnormal cardiac rhythms. In one example, a non-weighted candidate morphology template is generated based on far-field R-wave morphology. A weighted candidate morphology template is generated based on an ensemble average of the non-weighted candidate morphology template and a previous (i.e. active) morphology template. The previous morphology template is then selectively updated based on a comparison of additional R-waves against both the non-weighted and the weighted candidate templates. Thereafter, abnormal cardiac rhythms such as ventricular tachycardia and supraventricular tachycardia are discriminated using the updated morphology template based on newly-detected far-field R-waves. These techniques provide a method for updating the morphology discrimination template in response to long-term changes in morphology due to cardiac remodeling or cardiac disease progression. | 02-20-2014 |
20140052013 | METHOD FOR ANALYSIS OF COMPLEX RHYTHM DISORDERS - A method of analyzing a complex rhythm disorder in a human heart includes accessing signals from a plurality of sensors disposed spatially in relation to the heart, where the signals are associated with activations of the heart, and identifying a region of the heart having an activation trail that is rotational or radially emanating, where the activation trail is indicative of the complex rhythm disorder and is based on activation times associated with the activations of the heart. | 02-20-2014 |
20140066799 | SCHEMA FOR USING DYNAMIC COLOR AND PATTERN BACKGROUNDS FOR ELECTROCARDIOGRAM DISPLAYS AND ASSOCIATED SYSTEMS AND METHODS - The present technology is generally directed to schemas for using dynamic color and pattern backgrounds for electrocardiogram display and associated systems and methods. In a particular embodiment, a method of displaying an electrocardiogram rhythm can include receiving an electrocardiogram signal and applying an algorithm to the signal to determine a rhythm diagnosis or recommended therapy. The method can further include displaying a color and/or a pattern corresponding to the rhythm diagnosis or recommended therapy. In various embodiments, the method can be performed in real time or on a pre-recorded signal for post-event analysis. | 03-06-2014 |
20140094709 | BIOLOGICAL SIGNAL MANAGEMENT - Systems and techniques for managing biological signals. In one implementation, a method includes receiving a cardiac biological signal that includes information describing events, determining a merit of each event based on one or more of a severity of a cardiac condition associated with the event and a quality of the event, and handling a subset of the events that meet a merit criterion. The subset can be handled for medical purposes. | 04-03-2014 |
20140107512 | CARDIO MAPPING SYSTEM AND METHOD FOR CARDIO MAPPING - A method and system for determining the mechanism of cardiac arrhythmia in a patient is disclosed. The method basically entails measuring the impedance of cardiac tissue in a portion of the patient's heart using a catheter during an episode of supraventricular tachycardia to produce an iso-impedance map of that cardiac tissue on a video display and analyzing the pattern of the iso-impedance map to differentiate focal arrhythmia caused by a circumscribed region of focal firing and reentrant arrhythmia caused by a macroreentrant circuit. The method can also be used to identify regions of coherent rapidly conducting tissue e.g., Bachman's bundle or the inferoposterior pathway insertion points, to identify focal “mother rotors” throughout the left atrium that may participate in the generation and maintenance of atrial fibrillation and to identify areas of CAFE (complex atrial/fractionated electrograms) that truly reflect these mother rotors. | 04-17-2014 |
20140114204 | METHOD AND SYSTEM FOR DETECTION OF BIOLOGICAL RHYTHM DISORDERS - System, assembly and method are provided to facilitate reconstruction of cardiac information representing a complex rhythm disorder associated with a patient's heart to indicate a source of the heart rhythm disorder. The complex rhythm disorder can be treated by application of energy to modify the source of the rhythm disorder. | 04-24-2014 |
20140121552 | FIBRILLATION DETECTOR AND DEFIBRILLATOR - To provide a fibrillation detector and a defibrillator that are capable of correctly detecting within a short time a ventricular fibrillation (VF) that shows an irregular amplitude or shape, an R-wave detection unit R_DETECT_MEAN converts power of a frequency component making up an R wave of an electrocardio signal ECG into an approximately DC component, and outputs the converted power as R-wave power V_R. A T-wave detection unit T_DETECT_MEAN converts power of a frequency component making up a T wave of the electrocardio signal ECG into an approximately DC component, and outputs the converted power as T-wave power V_T. The R-wave power V_R and the T-wave power V_T are input to a comparison unit CMP, and the comparison unit CMP outputs a magnitude comparison result between the R-wave power V_R and the T-wave power V_T as a comparison signal sig_comp. | 05-01-2014 |
20140128758 | ELECTROCARDIOGRAM SIGNAL DETECTION - Apparatuses and methods for extracting, de-noising, and analyzing electrocardiogram signals. Any of the apparatuses described herein may be implemented as a (or as part of a) computerized system. For example, described herein are apparatuses and methods of using them or performing the methods, for extracting and/or de-noising ECG signals from a starting signal. Also described herein are apparatuses and methods for analyzing an ECG signal, for example, to generate one or more indicators or markers of cardiac fitness, including in particular indicators of atrial fibrillation. Described herein are apparatuses and method for determining if a patient is experiencing a cardiac event, such as an arrhythmia. | 05-08-2014 |
20140200471 | METHODS AND SYSTEMS FOR DETERMINING SPATIOTEMPORAL VARIABILITY FOR MAPPING CARDIAC FIBRILLATION - Methods and systems for determining optimal spatial resolution for mapping cardiac fibrillation in a patient, including obtaining one or more electrograms, having an initial spatial resolution; calculating at least one electrogram frequency; obtaining one or more electrograms, having a higher spatial resolution; calculating at least one electrogram frequency, having a higher spatial resolution; comparing at least one electrogram frequency having a higher spatial resolution with at least one electrogram frequency having an initial spatial resolution; iterating the steps above until the electrogram frequencies of the two compared electrograms are the same; and identifying at least one of minimum spatial resolution threshold and an optimal spatial resolution based on the step of comparing. | 07-17-2014 |
20140207012 | SYSTEMS AND METHODS FOR ANALYZING ELECTROCARDIOGRAMS TO DETECT VENTRICULAR FIBRILLATION - The present technology describes various embodiments of systems and methods for analyzing electrocardiograms to detect ventricular fibrillation. In several embodiments, systems for detecting ventricular fibrillation can be implemented without interrupting cardiopulmonary resuscitation. In one embodiment, a method of identifying a cardiac rhythm in a person includes recording an electrocardiogram signal of the person and stratifying the signal. A signal having a parameter value within a pre-determined range is categorized as a shockable ventricular fibrillation signal while a signal having a parameter value outside the pre-determined range is categorized as a non-shockable signal. | 07-24-2014 |
20140221861 | CONTRIBUTION OF OXIDATIVE STRESS TO AF ELECTROGRAMS - The invention relates generally to methods of detecting reactive oxygen species (ROS) in cardiac tissue and treatment modalities for ablating ROS-associated tissue in cardiac disease. The methods rely upon targeting ROS-associated cardiac tissue for ablation and/or gene therapy in a subject using analytical tools based upon a plurality of recorded atrial EGMs for a tissue to assess ROS content and underlying AF organization as a function of ROS blockade conditions. | 08-07-2014 |
20140236033 | Apparatus and Method for the Detection and Treatment of Atrial Fibrillation - Embodiments of the invention provide methods for the detection and treatment of atrial fibrillation (AF) and related conditions. One embodiment provides a method comprising measuring electrical activity of the heart using electrodes arranged on the heart surface to define an area for detecting aberrant electrical activity (AEA) and then using the measured electrical activity (MEA) to detect foci of AEA causing AF. A pacing signal may then be sent to the foci to prevent AF onset. Atrial wall motion characteristics (WMC) may be sensed using an accelerometer placed on the heart and used with MEA to detect AF. The WMC may be used to monitor effectiveness of the pacing signal in preventing AF and/or returning the heart to normal sinus rhythm (NSR). Also, upon AF detection, a cardioversion signal may be sent to the atria using the electrodes to depolarize an atrial area causing AF and return the heart to NSR. | 08-21-2014 |
20140257123 | ATRIAL FIBRILLATION ANALYZER, ATRIAL FIBRILLATION ANALYSIS SYSTEM, ATRIAL FIBRILLATION ANALYSIS METHOD, AND PROGRAM - An atrial fibrillation analyzer includes: an acquisition unit that acquires a waveform signal indicating a temporal change of a pulse wave or an electrocardiogram; an RR interval calculation unit that calculates a parameter corresponding to an average RR interval for each frame on the basis of a spectrum of each frame obtained by frequency analysis of the acquired waveform signal, and calculates an RR waveform signal indicating a temporal change of the parameter; a power calculation unit that calculates a temporal change of power of a predetermined frequency band in a frequency spectrum of the RR waveform signal; a variation coefficient calculation unit that calculates a variation coefficient of the average RR interval; an analysis unit that analyzes presence of atrial fibrillation on the basis of a set of the power and the variation coefficient; and a measurement unit that measures an amount of activity of a user. | 09-11-2014 |
20140257124 | ATRIAL FIBRILLATION ANALYZER AND PROGRAM - An atrial fibrillation analyzer includes: an acquisition unit that acquires a detected waveform signal indicating a detection result of a pulse wave or an electrocardiogram; an RR interval calculation unit that calculates, on the basis of a spectrum of each unit period obtained by frequency analysis performed on the acquired detected waveform signal every unit period longer than 4 seconds and equal to or shorter than 16 seconds, a parameter corresponding to an average RR interval of the unit period every unit period; a power calculation unit that calculates power of a frequency band determined in advance in an RR waveform signal indicating a temporal change of the average RR interval calculated by the RR interval calculation unit; and an analysis unit that determines whether or not the power satisfies specific conditions and outputs information indicating presence of atrial fibrillation from the determination result. | 09-11-2014 |
20140276160 | SYSTEM AND METHOD FOR AVOIDING UNDERSENSING OF VENTRICULAR FIBRILLATION - A medical device and associated method for detecting and treating tachyarrhythmias acquires a cardiac signal using electrodes coupled to a sensing module. Cardiac events are sensed from the cardiac signal and a processing module computes a first morphology metric for each sensed cardiac event occurring during a time segment of the cardiac signal. The first morphology metrics corresponding to an event originating in a ventricular chamber are counted. The first processing module computes a second morphology metric for the time segment of the cardiac signal in response to the count of the first morphology metrics meeting a threshold number of events. The time segment is classified as a shockable segment in response to the second morphology metric meeting a detection criterion. | 09-18-2014 |
20140323894 | STAGED RHYTHM DETECTION SYSTEM AND METHOD - A medical device and associated method for detecting and treating tachyarrhythmias acquires a cardiac signal using electrodes coupled to a sensing module. During an initial detection process, a shockable cardiac rhythm is detected by a processing module configured to compare the cardiac signal to a first set of detection criteria. By analyzing the cardiac signal, the processing module establishes at least one patient-specific detection threshold during the initial detection process. Upon establishing the at least one patient-specific detection threshold, the initial detection process is stopped, and a next detection process is started which includes comparing the cardiac signal to a second set of detection criteria including the at least one patient-specific detection threshold. In some embodiments, user programming of tachyarrhythmia detection parameters is not required. | 10-30-2014 |
20140330147 | ELECTROGRAM SUMMARY - Example techniques, systems, and devices select one or more portions of EGM signal data for presentation based on an identified cardiac episode type of the EGM signal data. For example, one or more processors are configured to receive cardiac electrogram (EGM) signal data collected from a medical device associated with a patient. The EGM signal data may include a detected cardiac episode identified as one of a plurality of episode types. The one or more processors may also be configured to select, based on the identified one of the plurality of episode types, one or more portions of the EGM signal data associated with the detected cardiac episode, and output the selected one or more portions of the EGM signal data. | 11-06-2014 |
20140330148 | CYCLE LENGTH ITERATION FOR THE DETECTION OF ATRIAL ACTIVATIONS FROM ELECTROGRAM RECORDINGS OF ATRIAL FIBRILLATION - A method is provided of analyzing a cardiac electrogram using a computer. In one step, a determination is made as to a plurality of cycle lengths between a plurality of activation peaks of the cardiac electrogram. In another step, a determination is made as to whether a mean of the plurality of cycle lengths meets at least one criteria. The method may be used to iteratively adjust a detection threshold level for detecting atrial fibrillation based on the cardiac electrogram. | 11-06-2014 |
20140330149 | Methods, Systems and Devices for Detecting Atrial Fibrillation - Disclosed herein are various embodiments of methods, systems and devices for detecting atrial fibrillation (AF) in a patient. According to one embodiment, a patient places his or her left and right hands around left and right electrodes and a hand-held atrial fibrillation detection device acquires an electrocardiogram (ECG) from the patient over a predetermined period of time such as, by way of example, one minute. After acquiring the ECG from the patient, the device processes and analyzes the ECG and makes a determination of whether the patient has AF. The device may further be configured to provide a visual or audio indication of whether the patient has AF, or does not have AF. The device may be employed in a health care provider's office without the need for complicated or expensive diagnostic equipment, and is capable of providing an on-the-spot and low-cost diagnosis of AF. The device may further be connected to a physician's computer in the office, which may be configured to store the results of the analysis and the patient's ECG, and which may further be configured to carry out additional processing and analyses of the acquired and processed data. Moreover, the physician's computer may be operably connected to a remote server configured to store, process and analyze the ECG and the results provided by the hand-held device. | 11-06-2014 |
20140336521 | INTRACARDIAC IMPEDANCE AND ITS APPLICATIONS - A system to measure intracardiac impedance includes implantable electrodes and a medical device. The electrodes sense electrical signals of a heart of a subject. The medical device includes a cardiac signal sensing circuit coupled to the implantable electrodes, an impedance measurement circuit coupled to the same or different implantable electrodes, and a controller circuit coupled to the cardiac signal sensing circuit and the impedance measurement circuit. The cardiac signal sensing circuit provides a sensed cardiac signal. The impedance measurement circuit senses intracardiac impedance between the electrodes to obtain an intracardiac impedance signal. The controller circuit determines cardiac cycles of the subject using the sensed cardiac signal, and detects tachyarrhythmia using cardiac-cycle to cardiac-cycle changes in a plurality of intracardiac impedance parameters obtained from the intracardiac impedance signal. | 11-13-2014 |
20140343445 | System and Computer Program Product for Automatically Distinguishing Atrial Flutter from Atrial Fibrillation - The present invention relates to a system for automatically distinguishing atrial flutter from atrial fibrillation based on a sequence of R-R-intervals of ECG-data. The system of the invention comprises means adapted to calculate or simulate an R-R-pattern from a model which is based on a periodic or almost periodic signal representing peaks of an atrial flutter signal, a first AV block scheme blocking respective ones of the atrial excitations while transmitting the others with a predetermined transmittal delay and at least one more AV-block scheme blocking respective ones of the excitations transmitted by the previous AV-block scheme and transmitting the others with a predetermined transmittal delay. The excitations transmitted by the last AV-block scheme constitute the calculated R-R-pattern. The system further comprises consistency checking means adapted to automatically check whether said sequence of R-R-intervals of the ECG-data is to some predetermined degree consistent with said calculated or simulated pattern. The system is configured to identify the ECG-data to be based on atrial flutter if said predetermined degree of consistency is found. | 11-20-2014 |
20140371616 | METHOD FOR ANALYSIS OF COMPLEX RHYTHM DISORDERS - A method of analyzing a complex rhythm disorder in a human heart includes accessing signals from a plurality of sensors disposed spatially in relation to the heart, where the signals are associated with activations of the heart, and identifying a region of the heart having an activation trail that is rotational or radially emanating, where the activation trail is indicative of the complex rhythm disorder and is based on activation times associated with the activations of the heart. | 12-18-2014 |
20150073288 | METHOD AND APPARATUS TO CONTROL CONDUCTION THROUGH THE HEART TO TREAT CARDIAC CONDITIONS - Control of conduction through a heart is described. A lead with a proximal end and a distal end is provided. The distal end of the lead is inserted into a target area. An agent is delivered through the lead to the target area. Delivery of the agent is monitored via a closed loop feedback system. | 03-12-2015 |
20150088019 | HIGH DENSITY ATRIAL FIBRILLATION CYCLE LENGTH (AFCL) DETECTION AND MAPPING SYSTEM - Systems and methods to assist in locating the focus of an atrial fibrillation include the association of atrial fibrillation cycle length values and statistics relating thereto with temporal locations on an electrogram of a given electrode, and/or the coordination of electrode locations with respective the spectral analyses of electrogram signals and further parameters and statistics relating thereto. Ablation therapy can proceed under guidance of such information. | 03-26-2015 |
20150126885 | RESUSCITATION ENHANCEMENTS - A system including a sensor interface coupled to a processor. The sensor interface is configured to receive and process an analog electrocardiogram signal of a subject and provide a digitized electrocardiogram signal sampled over a first time period and a second time period that is subsequent to the first time period. The processor is configured to receive the digitized electrocardiogram signal, to analyze a frequency domain transform of the digitized electrocardiogram signal sampled over the first and second time periods and determine first and second metrics indicative of metabolic state of a myocardium of the subject during the first and second time periods, respectively, to compare the first and second metrics to determine whether the metabolic state of the myocardium of the subject is improving, and to indicate administration of an intervention to the subject in response to a determination that the metabolic state is not improving. | 05-07-2015 |
20150297080 | NON-INVASIVE PORTABLE SYSTEM FOR THE MONITORING AND PRELIMINARY DIAGNOSIS OF ELECTROCARDIAC EVENTS IN REAL TIME - The present invention discloses a portable system for acquiring, processing, storage, diagnostics, remote alarm transmission and cardiac event in patients, which operates at a sampling rate of a minimum 1 kHz signals, making it quick and effective. The system is non-invasive and capable of detecting more than eight cardiac conditions, unlike other similar devices on the market. | 10-22-2015 |
20150327790 | METHOD FOR CREATING AND ANALYZING GRAPHS OF CARDIAC FUNCTION IN ATRIAL FIBRILLATION AND SINUS ARRHYTHMIA BASED ON THORACIC IMPEDANCE MEASUREMENTS - The present invention provides a method for creating and pathophysiologically analyzing graphs of cardiac function in atrial fibrillation and sinus arrhythmia by using thoracic impedance measurements. A two-dimensional scatter plot is created by applying (dZ/dt)min values corresponding to preceding RR interval (RR1) values and an approximate curve (i.e., cardiac function curve) is fitted to dots on the plot. The distribution pattern of the dots and the slope of the approximate curve allow for readily and visually evaluating cardiac function. Furthermore, a graph of the relationship between (dZ/dt)min values and RR1/pre-preceding RR interval (RR2) ratio values makes it possible to analyze pathophysiological mechanisms of cardiac function in more detail. This novel method of the present invention can be easily and repeatedly performed in atrial fibrillation and sinus arrhythmia with less of a physical burden on the patient, thereby being able to provide a very useful information for diagnosis and treatment. | 11-19-2015 |
20150359449 | ATRIAL FIBRILLATION DETECTION AND ASSOCIATED METHODS - A method to detect atrial fibrillation including the steps of receiving an electrical signal representative of a beating heart, measuring atrial activity over a time window of three or more beats, measuring beat interval variation over the time window, combining the measures of atrial activity and beat interval variation to produce an indication of an atrial fibrillation condition in the electrical signal, and generating an alert based on the indication of an atrial fibrillation condition. | 12-17-2015 |
20150366477 | USING INTRACARDIAC ELECTROGRAMS TO PREDICT LOCATION OF FIBROSIS AND AUTONOMIC NERVES IN THE HEART - A method of targeting fibrosis or autonomic nerve tissue for ablation in a subject is described. The method includes at least the following steps. The method includes performing at least one EGM analysis of a plurality of recorded atrial EGMs for a tissue in a region suspected of having fibrosis or autonomic nerve tissue. With regard to targeting fibrosis for ablation, the method includes determining one or more correlations of at least one AF EGM characteristic to a region having fibrosis from the plurality of recorded atrial EGMs for the tissue and determining whether the tissue contains dense fibrosis that would preclude effective ablation of the analysis region of the tissue. With regard to targeting autonomic nerve for ablation, the method includes determining whether one or more significant changes in EGM characteristics with autonomic blockade exist that would indicate the need to perform ablation of the analysis region of the tissue. | 12-24-2015 |
20160000346 | METHOD AND SYSTEM FOR EXTRACTING VENTRICULAR FIBRILLATION SIGNALS IN ELECTROCARDIOGRAM - This invention discloses a system and method for extracting VF signal in ECG recorded during uninterrupted CPR. The method and system applies an adaptive algorithm incorporating the EMD and least mean square (LMS) filtering to effectively model the CPR artifacts such as chest compression signals. Thus, A VF signal in ECG recorded during uninterrupted CPR can be extracted without deteriorating the reliability of the waveform parameter (i.e. AMSA) of shockability. The present invention enables uninterrupted CPR performed during recording ECG for accessing the shockability, so that an increase the probability of successful resuscitation is achieved. | 01-07-2016 |
20160045124 | VENTRICULAR FIBRILLATION DETECTION - Systems and techniques are disclosed for determining the onset and offset of a ventricular fibrillation event and for distinguishing ventricular fibrillation from noise. In some examples, an electrocardiogram (ECG) signal is obtained; a transform is applied to the ECG signal to obtain an analytical pair, the analytical pair including the ECG signal and the transformed ECG signal; a speed-amplitude is determined from the analytical pair; and an onset of a ventricular fibrillation event is identified based at least one of a value of a cost function of the speed-amplitude over a window and a quantity of occurrences the speed-amplitude crosses a threshold over the window. | 02-18-2016 |
20160045125 | ATRIAL FIBRILLATION DETECTION USING VENTRICULAR RATE VARIABILITY - Atrial fibrillation information can be determined from ventricular information or a ventricular location, such as using ventricular rate variability. An ambulatory medical device can receive indications of pairs of first and second ventricular rate changes of three temporally adjacent ventricular heart beats. A first count of instances of the pairs meeting a combined rate change magnitude characteristic and a second count of instances of the pairs in which both of the first and second ventricular rate changes are negative can be used to provide atrial fibrillation information. | 02-18-2016 |
20160120429 | METHOD AND SYSTEM FOR EXTRACTING VENTRICULAR FIBRILLATION SIGNALS IN ELECTROCARDIOGRAM - This invention discloses a system and a method for extracting VF signal in ECG recorded during uninterrupted CPR. The present invention provides a method for extracting a Ventricular fibrillation (VF) signal in Electrocardiography (ECG), comprising: receiving an ECG signal; adding a plurality of shadowing functions to the ECG signal, to obtain a plurality of modification signals; decomposing the plurality of modification signals by using an Empirical Mode Decomposition (EMD) method, to generate a plurality of Intrinsic Mode Functions (IMFs); calculating the sum of IMFs in different frequency regions based on time sequence, dividing by a number of the shadowing signal, to obtain a plurality of modification intrinsic mode functions; combining the plurality of modification IMFs with the same property, to obtain a shape function; modeling the shape functions to obtain a compression signal; and subtracting the compression signal from the ECG signal based on time sequence, to obtain the VF signal. | 05-05-2016 |
20160128595 | MEANS AND METHOD FOR THE DETECTION OF CARDIAC EVENTS - A system for detecting cardiac events and alerting the patient of the cardiac event issued by an implanted medical device. A processor detects a cardiac event and issues an activation signal to a patient alerting mechanism which emits an alarm during a first time interval followed by an alarm-off period of time. Reminder alarms are issued periodically following the alarm-off period of time. Reminder alarms are issued during reminder on-periods of time which are shorter than the first time interval. The alarm-off period and the time between periodic reminder alarms are greater than the alarm first time interval. A disabling device permits disabling of reminder alarms. | 05-12-2016 |
20160135707 | METHODS FOR DETECTING ATRIAL TACHYARRHYTHMIA IN IMPLANTABLE DEVICES WITHOUT DEDICATED ATRIAL SENSING - An apparatus comprises an implantable cardiac signal sensing circuit configured to provide a sensed depolarization signal from a ventricle and a processor. The processor includes a signal analyzer module and a tachyarrhythmia discrimination module. The signal analyzer module is configured to determine a measure of stability of ventricular (V−V) depolarization intervals using the depolarization signal, and determine a rate of change of the measure of stability. The tachyarrhythmia discrimination module is configured to detect an episode of tachyarrhythmia using the depolarization signal, determine whether the detected tachyarrhythmia is indicative of atrial tachyarrhythmia using the determined rate of change, and provide the determination to a user or process. | 05-19-2016 |
20160166166 | ATRIAL FIBRILLATION TREATMENT SYSTEMS AND METHODS | 06-16-2016 |
20160249823 | ELECTROCARDIOGRAM SIGNAL DETECTION | 09-01-2016 |