Patent application number | Description | Published |
20080243201 | PACER WITH COMBINED DEFIBRILLATOR TAILORED FOR BRADYCARDIA PATIENTS - A combination pacer/defibrillator is tailored for bradycardia patients. In one example, its shock-delivery specificity exceeds its sensitivity to shockable ventricular tachyarrhythmias. In another example, its specificity exceeds 95%, or 99%, or even 99.5%. Sensitivity is programmed to a high desired sensitivity value, but only if it can be done without decreasing the specificity below the desired specificity threshold value. This can be conceptualized as “avoiding at all costs” delivering false shocks, even at the expense of failing to deliver a shock to a treatable ventricular tachyarrhythmia. Specificity enhancements include, among other things, inhibiting shock delivery when the patient is breathing or not supine, using multiple channels or a high rate VT/VF detection threshold. The present pacer/defibrillator device could potentially save the lives of bradyarrhythmia patients who are not presently clinically indicated for a defibrillator/pacer, but who have an increased risk of sudden cardiac death due to one or more risk factors. | 10-02-2008 |
20080288009 | SELF-ADJUSTING ECG MORPHOLOGICAL FEATURE CORRELATION THRESHOLD - An apparatus comprising an implantable cardiac signal sensing circuit configured for sensing an intrinsic cardiac signal, a memory to store a template of a morphology of normal atrial-ventricular conduction, and a controller that includes a tachyarrhythmia detection circuit and a correlation circuit. The tachyarrhythmia detection circuit is configured for detecting a rhythm with elevated ventricular rate using the sensed intrinsic cardiac signal. The correlation circuit is configured for iteratively calculating a correlation between the sensed intrinsic cardiac signal and the template, and comparing the calculated correlation to a variable correlation threshold to determine whether the detected rhythm correlates to the template. The apparatus also includes a therapy circuit configured for inhibiting a ventricular tachycardia therapy when the detected rhythm correlates to the template. Other apparatuses and methods are described. | 11-20-2008 |
20090099616 | METHOD AND APPARATUS FOR CONCURRENT ATRIO-VENTRICULAR ANTI-TACHYCARDIA PACING - An implantable medical device delivers anti-tachyarrhythmia therapies including anti-tachycardia pacing (ATP). If a detected tachyarrhythmia is classified as a type suitable for treatment using ATP, the implantable medical device selects one of an atrial ATP (A-ATP) mode, a ventricular ATP (V-ATP) mode, and a concurrent atrio-ventricular ATP (concurrent AV-ATP) mode according to the characteristics of the detected tachyarrhythmia. The concurrent ATP mode is an ATP mode during which the atrial pacing pulses and the ventricular pacing pulses are delivered concurrently. In one embodiment, the concurrent AV-ATP mode includes a synchronized atrio-ventricular ATP (synchronized AV-ATP) mode during which atrial and ventricular pacing pulses are delivered synchronously and an independent atrio-ventricular ATP (independent AV-ATP) mode during which atrial and ventricular pacing pulses are delivered concurrently but timed independently. | 04-16-2009 |
20090216289 | CARDIAC RHYTHM MANAGEMENT SYSTEMS AND METHODS USING MULTIPLE MORPHOLOGY TEMPLATES FOR DISCRIMINATING BETWEEN RHYTHMS - This document describes systems, devices, and methods that use multiple morphology templates for discriminating between rhythms, such as supraventricular tachyarrhythmias (SVTs) and ventricular tachyarrhythmias (VTs), for delivering a countershock in response to a VT episode, but withholding delivery of such a countershock in response to an SVT episode. In certain examples, the particular morphology used for storing morphological features is selected at least in part using a sensor-indicated activity level of a subject, or a metabolic need of the subject. | 08-27-2009 |
20090299425 | 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. | 12-03-2009 |
20090299426 | Synchronized Ventricular Pacing to Promote Atrial Sensing - Methods and systems are described that involve synchronized ventricular pacing that promotes sensing of atrial events. The atrioventricular pacing delay is modified based on characteristics of previously sensed atrial events. The modified AV delay is implemented relative to a first atrial event. A second AV delay is implemented relative to a second atrial event if the second atrial event is sensed during the modified AV delay. A ventricular pacing pulse is delivered following the second AV delay. | 12-03-2009 |
20100057152 | SUSTAINING VENTRICULAR TACHYCARDIA DETECTION - An apparatus comprises an implantable ventricular depolarization sensing circuit configured to provide a sensed ventricular depolarization signal, a timer circuit configured to provide a ventricular time interval between ventricular depolarizations, and a controller circuit communicatively coupled to the ventricular depolarization sensing circuit and the timer circuit. The controller circuit includes a ventricular tachycardia (VT) detection circuit configured to declare an episode of VT when a number of accelerated beats are detected, calculate a hysteresis VT detection threshold interval, and deem whether the episode of VT persists using the hysteresis VT detection threshold interval. | 03-04-2010 |
20100069978 | DUAL SENSING FOR BRADY-TACHY PACEMAKER/ICD - A system detects events related to cardiac activity. The system comprises a primary cardiac signal sensing circuit, at least one secondary cardiac signal sensing circuit having a higher sensitivity than the primary sensing circuit, and a controller circuit coupled to the primary and secondary cardiac signal sensing circuits. The controller circuit determines a rate of depolarization using the primary sensing circuit and detects tachyarrhythmia using the rate. The controller circuit also detects tachyarrhythmia using the secondary sensing circuit and also deems the tachyarrhythmia valid if the controller circuit detects the tachyarrhythmia using both the primary and secondary sensing circuit. | 03-18-2010 |
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 |
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 |
20100280400 | RATE ABERRANT BEAT SELECTION AND TEMPLATE FORMATION - A cardiac rhythm management system can be used to detect episode beats associated with cardiac events in a subject's body. These events may be monitored and depolarization morphology information can be derived for candidate arrhythmic beats in an arrhythmia episode. An arrhythmic beat morphology template may be formed from selecting at least one of the candidate arrhythmic beats based upon user's labeling according to specific morphologies of one or more candidate episodes. Methods of use are also presented. | 11-04-2010 |
20100298902 | TACHYARRHYTHMIA SUDDEN ONSET DETECTION WITH HYSTERESIS - This document discusses, among other things, detection of a sudden onset of a tachyarrhythmia. A sudden onset of tachyarrhythmia is determined by monitoring changes in intrinsic ventricular rate, such as by using one or more sensing channels in the ICD. A lowest tachyarrhythmia rate threshold is accompanied by a slightly lower “hysteresis tachyarrhythmia rate threshold.” If a sudden onset of tachyarrhythmia is declared, the sudden onset status is not reset by the ventricular rate falling below the lowest tachyarrhythmia rate threshold, but is instead reset by the ventricular rate falling below the slightly lower hysteresis tachyarrhythmia rate threshold. | 11-25-2010 |
20100324613 | METHOD AND APPARATUS FOR RATE ACCURACY ENHANCEMENT IN VENTRICULAR TACHYCARDIA DETECTION - An implantable cardioverter/defibrillator (ICD) executes a rate accuracy enhancement algorithm to select measured atrial and ventricular intervals for classifying a detected tachycardia based on average atrial and ventricular rates calculated from the selected atrial and ventricular intervals. The detected tachycardia is classified as ventricular tachycardia (VT) if the average ventricular rate is substantially higher than the average atrial rate. | 12-23-2010 |
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 |
20110130672 | SELF-ADJUSTING ECG MORPHOLOGICAL FEATURE CORRELATION THRESHOLD - An apparatus comprises first and second sensing circuits, a template generator circuit, and a correlation circuit. The correlation circuit is configured to identify a first fiducial position in a third cardiac signal sensed using the first sensing circuit during a detected rhythm with elevated ventricular rate, align the template correlation features and the correlation features of a fourth cardiac signal using the first fiducial position, calculate a correlation using the correlation features of the template and the correlation features of the fourth cardiac signal, and iteratively searching for a replacement to the first fiducial position in the third cardiac signal according to the calculated correlation. | 06-02-2011 |
20110156706 | SENSING DURING MAGNETIC RESONANCE IMAGING - Physiologic information can be received from a subject during a portion of a magnetic resonance imaging (MRI) session using a sensing circuit of an implantable medical device (IMD). An indication of an active MRI scan can be received, and a time period to inhibit use of physiological information from the subject can be determined following the received indication of the active MRI scan. | 06-30-2011 |
20110160783 | MRI CARDIAC OPTIMIZATION - An implantable or other ambulatory device, such as a pacer, defibrillator, or other cardiac function management device, can use imaging information, such as one or more of cardiac functional magnetic resonance imaging (fMRI) information or cardiac magnetic resonance imaging (MRI) information, such as for helping optimize one or more parameters of the implantable or other ambulatory device. | 06-30-2011 |
20110160786 | IMPLANTABLE DEVICE FAILSAFE MODE FOR MRI - An implantable device, such as a pacer, defibrillator, or other cardiac rhythm management device, can include a failsafe backup, such as a separate and independent safety core that can assume control over operation of the implantable device from a primary controller. In an example, the safety core can include a normal first safety core operating mode and a magnetic resonance imaging (MRI) second safety core operating mode that can provide different functionality from the normal first safety core operating mode. | 06-30-2011 |
20110160803 | IMPLANTABLE DEVICE WITH BIAS FOR MRI - An ambulatory or implantable device, such as a pacer, defibrillator, or other cardiac rhythm management device, can tolerate magnetic resonance imaging (MRI) or other noise without turning on an integrated circuit diode by selectively providing a bias voltage that can overcome an expected induced voltage resulting from the MRI or other noise. | 06-30-2011 |
20110160808 | IMPLANTABLE MEDICAL DEVICE INCLUDING ISOLATION TEST CIRCUIT - An implantable medical device can include a hermetically-sealed implantable housing, an exposed first conductor located on or near the housing, and at least one insulated second conductor located near the exposed first conductor. In an example, the implantable medical device can include an isolation test circuit to provide a test stimulus to the exposed first conductor and configured to measure a portion of the test stimulus coupled to the second conductor. | 06-30-2011 |
20110288603 | POST-SHOCK RECOVERY MONITORING FOR TACHYARRHYTHMIA DISCRIMINATION - A cardiac rhythm management device is configured to discriminate between ventricular and supraventricular tachycardias (referred to as SVT/VT discrimination) by utilizing a morphology criterion in which the morphology of electrogram waveforms during ventricular beats are analyzed to determine if the beats are normally conducted. After the delivery of a cardioversion/defibrillation shock, however, the intraventricular conduction system is left in a modified state which alters the subsequently generated electrogram signal. Use of the morphology criterion for to SVT/VT discrimination is discontinued after delivery of such a shock and resumed after a predetermined minimum number of normally conducted ventricular beats has been detected. | 11-24-2011 |
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 |
20120158089 | LEAD FAULT DETECTION FOR IMPLANTABLE MEDICAL DEVICE - An implantable medical device can include a therapy circuit coupled to a therapy delivery terminal, the therapy circuit configured to generate a specified electrostimulation therapy for delivery to a tissue site via the therapy delivery terminal, and a measurement circuit for measuring at least two impedances of a first terminal combination including the therapy delivery terminal, the two impedances corresponding to at least two instances of excitation separated enough in time to capture an impedance artifact due at least in part to a motion of the heart, such as to determine an electrostimulation therapy lead status at least in part using the at least two impedances. | 06-21-2012 |
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 |
20120215273 | METHOD AND APPARATUS FOR CONCURRENT ATRIO-VENTRICULAR ANTI-TACHYCARDIA PACING - An implantable medical device delivers anti-tachyarrhythmia therapies including anti-tachycardia pacing (ATP). If a detected tachyarrhythmia is classified as a type suitable for treatment using ATP, the implantable medical device selects one of an atrial ATP (A-ATP) mode, a ventricular ATP (V-ATP) mode, and a concurrent atrio-ventricular ATP (concurrent AV-ATP) mode according to the characteristics of the detected tachyarrhythmia. The concurrent ATP mode is an ATP mode during which the atrial pacing pulses and the ventricular pacing pulses are delivered concurrently. In one embodiment, the concurrent AV-ATP mode includes a synchronized atrio-ventricular ATP (synchronized AV-ATP) mode during which atrial and ventricular pacing pulses are delivered synchronously and an independent atrio-ventricular ATP (independent AV-ATP) mode during which atrial and ventricular pacing pulses are delivered concurrently but timed independently. | 08-23-2012 |
20130226266 | SYSTEMS AND METHODS FOR MODIFYING IMPEDANCE ALONG ELECTRICAL PATHS OF ELECTRICAL STIMULATION SYSTEMS - An implantable medical device system includes a control module with a connector assembly for electrically coupling to a lead. The control module includes a plurality of feedthrough interconnects extending from the connector assembly to an electronic subassembly disposed in a sealed housing. The plurality of feedthrough interconnects include a first feedthrough interconnect and a second feedthrough interconnect. Impedance circuitry disposed in the control module modulates impedance associated with terminals and conductors of the lead. The impedance circuitry includes a plurality of impedance elements each coupled electrically to a different feedthrough interconnect. Each impedance element has a pre-defined impedance. The plurality of impedance elements include a first impedance element electrically coupled to the first feedthrough interconnect and a second impedance element electrically coupled to the second feedthrough interconnect. The pre-defined impedance of the first impedance element is different than the pre-defined impedance of the second impedance element. | 08-29-2013 |
20130241573 | SYSTEMS AND METHODS FOR OBTAINING AND USING INCIDENT FIELD TRANSFER FUNCTIONS OF ELECTRICAL STIMULATION SYSTEMS - A method of estimating response of a medical lead to an electromagnetic field includes providing a medical lead having a proximal end, a distal end, a plurality of electrodes disposed along the distal end, a plurality of terminals disposed along the proximal end, and a plurality of conductors extending along the medical lead and electrically coupling the electrodes to the terminals; individually applying a test field at each of a plurality of test positions along the medical lead using at least one excitation probe; for each application of the test field, determining a response to the application of the test field at one or more of the electrodes or terminals; generating a transfer function using a combination of the responses determined for the applications of the test field; and using the transfer function to estimate a response of the medical lead to an electromagnetic field. | 09-19-2013 |
20130338725 | CARDIAC RESPONSE CLASSIFICATION USING MULTISITE SENSING AND PACING - Methods and devices for classifying a cardiac pacing response involve using a first electrode combination for pacing and a second electrode combination for sensing a cardiac signal following pacing. The cardiac response to pacing may be classified using the sensed cardiac signal. One process involves using the sensed cardiac signal to detect the cardiac response as a fusion/pseudofusion beat. Another process involves using the sensed cardiac signal to classify the cardiac response to pacing as one of at least three cardiac response types. | 12-19-2013 |
20130345777 | NEUROSTIMULATION SYSTEM FOR ENABLING MAGNETIC FIELD SENSING WITH A SHUT-DOWN HALL SENSOR - An implantable medical device capable of being placed between a first operational mode and a second operational mode. The medical device comprises a magnetic field sensing device configured for outputting a signal in response to sensing a magnetic field. The medical device further comprises a logic circuit configured for continuously asserting the signal during a time period when the neurostimulation device is in the first operational mode, and intermittently asserting the signal during at least one time period when the neurostimulation device is in the second operational mode. The medical device further comprises a delay circuit configured for introducing a time delay into the asserted signal, the time delay being less than the time period, but greater than each of the at least one time period. The medical device further comprises control circuitry configured for performing a function in response to receiving the delayed signal at a first input terminal. | 12-26-2013 |
20140155970 | IMPLANTABLE MEDICAL DEVICE HAVING ELECTROMAGNETIC INTERFERENCE FILTER DEVICE TO REDUCE POCKET TISSUE HEATING - An active implantable medical device (AIMD) for use with a medical lead carrying at least one lead electrode. The AIMD comprises interior electronic circuitry configured for performing a medical function via the medical lead, an electrically conductive case containing the interior electronic circuitry, at least one electrical terminal configured for electrically coupling the electronic circuitry respectively to the lead electrode(s), and an inductive element coupled in series between the electrical terminal(s) and the case. The inductive element is configured for hindering the shunting of electrical current from the at least one electrical terminal to the case that has been induced by electromagnetic interference (EMI) impinging on the medical lead. | 06-05-2014 |
20140296699 | IMPLANTABLE DEVICE WITH BIAS FOR MRI - An ambulatory or implantable device, such as a pacer, defibrillator, or other cardiac rhythm management device, can tolerate magnetic resonance imaging (MRI) or other noise without turning on an integrated circuit diode by selectively providing a bias voltage that can overcome an expected induced voltage resulting from the MRI or other noise. | 10-02-2014 |
20140378820 | SYSTEMS AND METHOD FOR AUTOMATICALLY DETECTING AN MRI ENVIRONMENT FOR PATIENT IMPLANTED WITH MEDICAL DEVICE - Methods, medical devices, and magnetic resonance imaging (MRI) systems are provided. A patient implanted with a medical device is exposed to a time-varying magnetic field having a signature, thereby inducing mechanical vibrations in at least one component of the medical device. A vibrational characteristic of the mechanical vibrations induced in the component(s) is detected. The vibrational characteristic is analyzed, and the signature of the magnetic field is identified based on the analyzed vibrational characteristic. The medical device is automatically switched from a first operational mode to a second operational mode when the signature is identified. | 12-25-2014 |
20150051662 | CARDIAC RESPONSE CLASSIFICATION USING MULTISITE SENSING AND PACING - Methods and devices for classifying a cardiac pacing response involve using a first electrode combination for pacing and a second electrode combination for sensing a cardiac signal following pacing. The cardiac response to pacing may be classified using the sensed cardiac signal. One process involves using the sensed cardiac signal to detect the cardiac response as a fusion/pseudofusion beat. Another process involves using the sensed cardiac signal to classify the cardiac response to pacing as one of at least three cardiac response types. | 02-19-2015 |